78 results on '"Poston RS"'
Search Results
2. Letter by Landis et al regarding article 'Aprotinin does not increase the risk of renal failure in cardiac surgery patients'.
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Landis RC, Taylor KM, Poston RS, Furnary AP, Wu Y, Hiratzka LF, Grunkemeier GL, and Page US III
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- 2008
Catalog
3. Blood product transfusion in association with coronary artery bypass grafting: proceed with caution.
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Malone DL, Poston RS, and Hess JR
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- 2006
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4. Mortality benefit with prasugrel in the TRITON-TIMI 38 coronary artery bypass grafting cohort: risk-adjusted retrospective data analysis.
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Smith PK, Goodnough LT, Levy JH, Poston RS, Short MA, Weerakkody GJ, Lenarz LA, Smith, Peter K, Goodnough, Lawrence T, Levy, Jerrold H, Poston, Robert S, Short, Mary A, Weerakkody, Govinda J, and Lenarz, Leroy A more...
- Abstract
Objectives: The objective of this study was to characterize the bleeding, transfusion, and other outcomes of patients related to the timing of prasugrel or clopidogrel withdrawal before coronary artery bypass grafting (CABG).Background: There is little evidence to guide clinical decision making regarding the use of prasugrel in patients who may need urgent or emergency CABG. Experience with performing CABG in the presence of clopidogrel has raised concern about perioperative bleeding complications that are unresolved.Methods: A subset of the TRITON-TIMI 38 study (Trial to Assess Improvement in Therapeutic Outcomes by Optimizing Platelet Inhibition with Prasugrel-Thrombolysis In Myocardial Infarction 38), in which patients with acute coronary syndrome were randomized to treatment with aspirin and either clopidogrel or prasugrel, underwent isolated CABG (N = 346). A supplemental case report form was designed and administered, and the data combined with the existing TRITON-TIMI 38 database. Baseline imbalances were corrected for using elements of the European System for Cardiac Operative Risk Evaluation and The Society of Thoracic Surgeons predictive algorithm.Results: A significantly higher mean 12-h chest tube blood loss (655 ± 580 ml vs. 503 ± 378 ml; p = 0.050) was observed with prasugrel compared with clopidogrel, without significant differences in red blood cell transfusion (2.1 U vs. 1.7 U; p = 0.442) or the total donor exposure (4.4 U vs. 3.0 U; p = 0.463). All-cause mortality was significantly reduced with prasugrel (2.31%) compared with 8.67% with clopidogrel (adjusted odds ratio: 0.26; p = 0.025).Conclusions: Despite an increase in observed bleeding, platelet transfusion, and surgical re-exploration for bleeding, prasugrel was associated with a lower rate of death after CABG compared with clopidogrel. [ABSTRACT FROM AUTHOR] more...- Published
- 2012
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5. Coronary computed tomography angiography following robotic coronary artery bypass grafting surgery: Systematic approach to image analysis and practical considerations.
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Pasha AK, Lee JZ, Poston RS, and Abidov A
- Abstract
Standard open chest Coronary Artery Bypass Grafting (CABG) has evolved over last couple of decades. With advancement in minimally invasive procedures, Robotic CABG (RCABG) is still in its evolution phase. There is dearth of experienced surgeons in this complicated field and lack of data to verify it clinical safety. in this review, we intend to describe the utility of Cardiac Computed Tomography Angiography (CCTA) in assessment of graft anatomy and quality, grafting strategy, distal graft anastomosis site evaluation and detection of complications associated with RCABG. CCTA appears to provide valuable information regarding the visualization of grafts, target coronary arteries and other cardiac and non-cardiac structures., Competing Interests: None for all authors., (© 2021 The Authors.) more...
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- 2021
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6. OR and ICU teams 'running in parallel' at the end of cardiothoracic surgery improves perceptions of handoff safety.
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Hamid S, Joyce F, Burza A, Yang B, Le A, Saleh A, and Poston RS
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- Humans, Intensive Care Units, Operating Rooms, Perception, Patient Handoff, Running
- Abstract
The transfer of a cardiac surgery patient from the operating room (OR) to the intensive care unit (ICU) is both a challenging process and a critical period for outcomes. Information transferred between these two teams-known as the 'handoff'-has been a focus of efforts to improve patient safety. At our institution, staff have poor perceptions of handoff safety, as measured by low positive response rates to questions found in the Agency for Health Care Research and Quality (AHRQ) Hospital Survey on Patient Safety Culture (HSOPS). In this quality improvement project, we developed a novel handoff protocol after cardiac surgery where we invited the ICU nurse and intensivist into the OR to receive a face-to-face handoff from the circulating nurse, observe the final 30 min of the case, and participate in the end-of-case debrief discussions. Our aim was to increase the positive response rates to handoff safety questions to meet or surpass the reported AHRQ national averages. We used plan, do, study, act cycles over the course of 123 surgical cases to test how our handoff protocol was leading to changes in perceptions of safety. After a 10-month period, we achieved our aim for four out of the five HSOPS questions assessing safety of handoff. Our results suggest that having an ICU team 'run in parallel' with the cardiac surgical team positively impacts safety culture., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.) more...
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- 2021
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7. Simulation trainer for practicing emergent open thoracotomy procedures.
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Hamilton AJ, Prescher H, Biffar DE, and Poston RS
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- Clinical Competence, Emergencies, Feasibility Studies, Humans, Interprofessional Relations, Patient Care Team, Thoracotomy methods, Time Factors, United States, Education, Medical, Continuing methods, Manikins, Models, Educational, Thoracic Surgery education, Thoracotomy education
- Abstract
Background: An emergent open thoracotomy (OT) is a high-risk, low-frequency procedure uniquely suited for simulation training. We developed a cost-effective Cardiothoracic (CT) Surgery trainer and assessed its potential for improving technical and interprofessional skills during an emergent simulated OT., Materials and Methods: We modified a commercially available mannequin torso with artificial tissue models to create a custom CT Surgery trainer. The trainer's feasibility for simulating emergent OT was tested using a multidisciplinary CT team in three consecutive in situ simulations. Five discretely observable milestones were identified as requisite steps in carrying out an emergent OT; namely (1) diagnosis and declaration of a code situation, (2) arrival of the code cart, (3) arrival of the thoracotomy tray, (4) initiation of the thoracotomy incision, and (5) defibrillation of a simulated heart. The time required for a team to achieve each discrete step was measured by an independent observer over the course of each OT simulation trial and compared., Results: Over the course of the three OT simulation trials conducted in the coronary care unit, there was an average reduction of 29.5% (P < 0.05) in the times required to achieve the five critical milestones. The time required to complete the whole OT procedure improved by 7 min and 31 s from the initial to the final trial-an overall improvement of 40%., Conclusions: In our preliminary evaluation, the CT Surgery trainer appears to be useful for improving team performance during a simulated emergent bedside OT in the coronary care unit., (Copyright © 2015 Elsevier Inc. All rights reserved.) more...
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- 2015
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8. A nationwide survey on perception, experience, and expectations of hybrid coronary revascularization among top-ranked US hospitals.
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Harskamp RE, Halkos ME, Xian Y, Szerlip MA, Poston RS, Mick SL, Lopes RD, Tijssen JG, de Winter RJ, and Peterson ED
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- Coronary Angiography, Coronary Artery Disease diagnostic imaging, Coronary Artery Disease epidemiology, Female, Humans, Male, Middle Aged, Morbidity trends, Treatment Outcome, United States epidemiology, Coronary Artery Disease surgery, Hospitals statistics & numerical data, Myocardial Revascularization methods, Population Surveillance methods
- Abstract
Background: Hybrid coronary revascularization (HCR) combines a surgical and percutaneous approach for treatment of multivessel coronary artery disease., Methods: A survey was conducted among 200 cardiologists and cardiac surgeons from 100 top-ranked US hospitals. Questions were asked involving the perception, experience, and future expectations of HCR., Results: Of physicians invited to the survey, 90 completed the survey (45.5%). Relative to nonresponders, responders were more often affiliated with an academic institution (80.0% vs 61.8%, P=.005), with higher patient volumes, and with the availability of a hybrid operating room (90.0% vs 67.3%, P<.001). Survey responders felt that HCR should be considered in an older and relatively healthy patient population without complex lesions. Cardiac surgeons were more favorable to use HCR in patients with chronic lung disease (42.0% vs 10.0%, P<.001) or renal failure (28.0% vs 15.0%, P=.06). Among responders with HCR experience (n=54), 94% reported good to excellent results, and the learning curve differed depending on the surgical technique used. Inappropriate patient selection (41.2%) was the most common cause for complications. Three-quarter of responders believe that the future role for HCR will expand in the next decade. Important determinants of greater HCR use in the future were collaborative associations between cardiac surgeons and cardiologists (86.7%), appropriate patient selection (67.8%), and the outcomes of ongoing clinical trials (57.8%)., Conclusion: In this nationwide survey, cardiologists and cardiac surgeons felt that HCR is a reasonable alternative technique for coronary revascularization among suitable patients. Most felt that use of HCR would increase in the next decade., (Copyright © 2015 Elsevier Inc. All rights reserved.) more...
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- 2015
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9. Transfusion outcomes in patients undergoing coronary artery bypass grafting treated with prasugrel or clopidogrel: TRITON-TIMI 38 retrospective data analysis.
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Goodnough LT, Smith PK, Levy JH, Poston RS, Short MA, Weerakkody GJ, and LeNarz LA
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- Clopidogrel, Humans, Prasugrel Hydrochloride, Retrospective Studies, Risk Factors, Ticlopidine therapeutic use, Acute Coronary Syndrome surgery, Coronary Artery Bypass, Piperazines therapeutic use, Platelet Aggregation Inhibitors therapeutic use, Platelet Transfusion, Thiophenes therapeutic use, Ticlopidine analogs & derivatives
- Abstract
Objective: Coronary artery bypass grafting-related bleeding and associated transfusion is a concern with dual antiplatelet therapy in patients with acute coronary syndromes. The objective of the present study was to characterize a potential risk-adjusted difference in transfusion requirements between prasugrel and clopidogrel cohorts., Methods: The data from 422 patients undergoing isolated coronary artery bypass grafting from the TRial to assess Improvement in Therapeutic Outcomes by optimizing platelet InhibitioN with prasugrel Thrombolysis In Myocardial Infarction 38 were analyzed retrospectively., Results: We found no difference in baseline transfusion risk scores between cohorts. As predicted, the number of units of red blood cells transfused perioperatively correlated with the transfusion risk score (P < .0001). Overall, the 12-hour chest tube drainage volumes and platelet transfusion rates in the prasugrel cohort were significantly greater. However, no statistically significant differences were found in the number of red blood cell transfusions, total hemostatic components transfused, or total blood donor exposure. A significantly greater number of platelet units were transfused postoperatively in the prasugrel patients who underwent surgery within 5 days or less after withdrawal of drug. In an analysis adjusted for the predicted risk of mortality, total donor exposure was not associated with increased mortality., Conclusions: The use of prasugrel compared with clopidogrel was associated with greater 12-hour chest tube drainage volumes and platelet transfusion rates but without any significant differences in red blood cell transfusions, total hemostatic components transfused, or total blood donor exposure., (Copyright © 2013 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.) more...
- Published
- 2013
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10. Reply: To PMID 21996436.
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Kiani S and Poston RS
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- Female, Humans, Male, Coronary Artery Bypass, Endoscopy methods, Saphenous Vein transplantation, Tissue and Organ Harvesting methods, Vascular Patency physiology
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- 2013
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11. Managing port-site bleeding during less invasive coronary artery bypass grafting.
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Kiani S, Brecht ML, Lovinger K, and Poston RS
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- Aged, Case-Control Studies, Chest Tubes, Coronary Artery Bypass instrumentation, Coronary Artery Disease diagnostic imaging, Drainage methods, Erythrocyte Transfusion methods, Female, Follow-Up Studies, Humans, Injections, Intralesional, Linear Models, Male, Middle Aged, Minimally Invasive Surgical Procedures, Postoperative Hemorrhage diagnosis, Radiography, Reference Values, Retrospective Studies, Risk Assessment, Severity of Illness Index, Treatment Outcome, Coronary Artery Bypass methods, Coronary Artery Disease surgery, Hemostatics therapeutic use, Postoperative Hemorrhage therapy, Robotics methods, Vascular Access Devices adverse effects
- Abstract
Introduction: Robotic-assisted coronary artery bypass grafting (r-CABG) requires the placement of ports bluntly through the chest wall. When removed, these ports create bleeding sites that can be difficult to detect and treat. This study evaluated whether a topical hemostatic agent placed locally within these sites helps to reduce bleeding and blood product requirements., Methods: We retrospectively analyzed outcomes for r-CABG cases where 5 mL of a flowable hemostatic agent was injected locally within all port sites (hemostat group, n = 62) compared with patients whose port sites were untreated (controls, n = 131). Outcomes included chest tube output, red blood cell (RBC) transfusions, length of hospital stay, and the risk of reoperation for bleeding. Analyses were adjusted for risk factors known to influence bleeding and Society of Thoracic Surgeons (STS) risk score as a weighted composite of variables, which controls for patient and clinical variables., Results: The 2 study groups had similar baseline characteristics and underwent the same r-CABG procedure. The hemostat group had significant reductions in RBC transfusion (24.2% versus 40.8% receiving blood; P = .026; 0.44 versus 1.39 U transfused postoperatively, P = .024). After adjustment for bleeding risks (using STS risk score), differences in transfusions remained significant. Reoperation rates for bleeding, length of stay, chest tube drainage, and intraoperative transfusions were not significantly different in the 2 groups., Conclusions: There was significantly reduced postoperative bleeding and less exposure to blood products in the hemostat group. These findings suggest that undetected bleeding from sites used for port access serves as an underappreciated source of morbidity after r-CABG. more...
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- 2012
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12. Risk of renal dysfunction after less invasive multivessel coronary artery bypass grafting.
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Kiani S, Brown AK, Kurian DJ, Henkin S, Flynn MM, Thirumavalavan N, Desai PH, and Poston RS
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- Aged, Coronary Artery Bypass adverse effects, Female, Follow-Up Studies, Humans, Incidence, Male, Middle Aged, Postoperative Complications, Prospective Studies, Renal Insufficiency epidemiology, Renal Insufficiency physiopathology, Risk Factors, Survival Rate trends, United States epidemiology, Coronary Artery Bypass methods, Coronary Artery Disease surgery, Glomerular Filtration Rate physiology, Renal Insufficiency etiology, Thoracotomy adverse effects
- Abstract
Objective: Several centers have established that off-pump, multivessel coronary artery bypass grafting performed via a small thoracotomy (MVST) is feasible. However, this procedure can be challenging when posterolateral coronary targets need to be grafted. We hypothesized that use of cardiopulmonary bypass via peripheral access (MVST-PA) would improve outcomes compared with a completely off-pump approach (OP-MVST)., Methods: This was a prospective observational study of patients undergoing OP-MVST (n = 46) versus MVST-PA (n = 45) using bilateral internal mammary artery grafts onto the left anterior descending coronary artery and circumflex/right coronary artery distribution. Hemostasis was quantified by measuring platelet function (aggregometry), chest tube output, thrombolysis in myocardial infarction bleeding score (%hematocrit change at 24 hours), and transfusion requirements. The rate of mortality and major morbidity at 30 days was defined according to The Society of Thoracic Surgeons criteria. Estimated glomerular filtration rate (normalized to baseline levels) was determined daily until discharge., Results: The OP-MVST versus MVST-PA groups had similar risk factors at baseline and risks of composite morbidity/mortality at 30 days. However, renal failure was significantly increased after OP-MVST (10.87 vs 0%, P = 0.05), and MVST-PA affected hemostasis as evidenced by inhibition of platelet function (latency to response on aggregometry, 29.9 vs 17.9 seconds; P = 0.04) and higher transfusion requirement (2.31 vs 0.85 units of red blood cells/patient, P = 0.04; 55.6% vs 34.8% transfused; P = 0.059). However, 24-hour chest tube output was similar (645 vs 750 mL; P = 0.53)., Conclusions: In comparison with a completely off-pump strategy, use of cardiopulmonary bypass to assist MVST reduced the risk of renal dysfunction with only modest tradeoffs in other morbidities, for example, altered coagulation and higher transfusion requirements. These data justify further study of the effect of MVST-PA on renal complications. more...
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- 2012
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13. Endoscopic venous harvesting by inexperienced operators compromises venous graft remodeling.
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Kiani S, Desai PH, Thirumvalavan N, Kurian DJ, Flynn MM, Zhao X, and Poston RS
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- Aged, Female, Humans, Male, Reproducibility of Results, Saphenous Vein cytology, Saphenous Vein physiology, Tomography, Optical Coherence, Coronary Artery Bypass, Endoscopy methods, Saphenous Vein transplantation, Tissue and Organ Harvesting methods, Vascular Patency physiology
- Abstract
Background: Endoscopic vein harvesting (EVH) is the standard of care for coronary artery bypass grafting (CABG) in the United States, but recent comparisons with open harvesting suggest that conduit quality and outcomes may be compromised in EVH. To test the hypothesis that problems with EVH may relate to its learning curve and conduit quality, we analyzed the quality and early function of conduits procured by technicians with varying experience in EVH., Methods: Experienced (more than 900 cases, n=55 patients) and novice (less than 100 cases, n=30 patients) technicians performed EVH during CABG. Subsequently, optical coherence tomography (OCT) was used to examine the conduits for vascular injury, with segments identified as injured being further examined for gene expression with an array of genes related to tissue injury. Conduit diameter was measured intra- and postoperatively (day 5 and 6 months, respectively) with OCT and computed tomographic angiography., Results: Endoscopic vein harvesting by novice harvesters resulted in a greater number of discrete graft injuries and greater expression of tissue-injury genes than EVH done by experienced harvesters. Regression analysis revealed an association between shear stress and early dilation of engrafted vessels (positive remodeling) (R2=0.48, p<0.01). Injured veins showed blunted positive remodeling at 5 days after harvesting and a greater degree of late lumen loss at 6 months., Conclusions: Under normal conditions, intraluminal shear stress leads to positive remodeling of vein grafts during the first postoperative week. Injury to conduits, a frequent sequela of the learning curve for EVH, was a predictor of early graft failure and of blunted positive remodeling and greater negative remodeling of endoscopically harvested vein grafts. Given the current annual volume of cases in which EVH is used, rigorous monitoring of the learning curve for this procedure represents an important and unrecognized issue in public health., (Copyright © 2012 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.) more...
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- 2012
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14. Change management and an innovative approach to heart bypass surgery.
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Kurian D, Gorcos J, Meinke S, Thirumavalavan N, Mizrahi I, Kiani S, Desai P, and Poston RS
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- Humans, Organizational Case Studies, Personnel Management, Surgery Department, Hospital organization & administration, Coronary Artery Bypass methods, Diffusion of Innovation
- Published
- 2011
15. Simulation in coronary artery anastomosis early in cardiothoracic surgical residency training: the Boot Camp experience.
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Fann JI, Calhoon JH, Carpenter AJ, Merrill WH, Brown JW, Poston RS, Kalani M, Murray GF, Hicks GL Jr, and Feins RH
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- Anastomosis, Surgical, Animals, Clinical Competence, Computer Simulation, Curriculum, Humans, Models, Animal, Motor Skills, Program Development, Program Evaluation, Surveys and Questionnaires, Suture Techniques education, Swine, Task Performance and Analysis, Video Recording, Coronary Artery Bypass education, Coronary Vessels surgery, Education, Medical, Graduate, Internship and Residency, Thoracic Surgical Procedures education
- Abstract
Objective: We evaluated focused training in coronary artery anastomosis with a porcine heart model and portable task station., Methods: At "Boot Camp," 33 first-year cardiothoracic surgical residents participated in 4-hour coronary anastomosis sessions (6-7 attending surgeons per group of 8-9 residents). At beginning, midpoint, and session end, anastomosis components were assessed on a 3-point rating scale (1 good, 2 average, 3 below average). Performances were video recorded and reviewed by 3 surgeons in a blinded fashion. Participants completed questionnaires at session end, with follow-up surveys at 6 months., Results: Ten to 18 end-to-side anastomoses with porcine model and task station were performed. Initial assessments ranged from 2.11 +/- 0.58 (forceps use) to 2.44 +/- 0.48 (needle angles). Midpoint scores ranged from 1.76 +/- 0.63 (forceps use) to 1.91 +/- 0.49 (needle angles). Session end scores ranged from 1.29 +/- 0.45 (needle holder use) to 1.58 +/- 0.50 (needle transfer and suture management and tension; P < .001). Video recordings confirmed improved performance (interrater reliability >0.5). All respondents agreed that task station and porcine model were good methods of training. At 6 months, respondents noted that the anastomosis session provided a basis for training; however, only slightly more than half continued to practice outside the operating room., Conclusions: Four-hour focused training with porcine model and task station resulted in improved ability to perform anastomoses. Boot Camp may be useful in preparing residents for coronary anastomosis in the clinical setting, but emphasis on simulation development and deliberate practice is necessary., (Published by Mosby, Inc.) more...
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- 2010
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16. Challenges of telerobotics in coronary bypass surgery.
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Desai PH, Tran R, Steinwagner T, and Poston RS
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- United States, Coronary Artery Bypass trends, Forecasting, Robotics trends, Telemedicine trends
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- 2010
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17. A randomized clinical trial investigating the relationship between aprotinin and hypercoagulability in off-pump coronary surgery.
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Desai PH, Kurian D, Thirumavalavan N, Desai SP, Ziu P, Grant M, White C, Landis RC, and Poston RS
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- Blood Coagulation Tests, Blood Platelets metabolism, Double-Blind Method, Erythrocyte Transfusion, Graft Occlusion, Vascular blood, Graft Occlusion, Vascular etiology, Humans, Peptide Fragments blood, Platelet Adhesiveness drug effects, Platelet Aggregation drug effects, Platelet Function Tests, Postoperative Hemorrhage prevention & control, Prospective Studies, Prothrombin, Receptor, PAR-1 blood, Thrombin metabolism, Thrombosis blood, Thrombosis etiology, Treatment Outcome, Wound Healing drug effects, Platelet Aggregation Inhibitors, Aprotinin therapeutic use, Blood Coagulation drug effects, Blood Platelets drug effects, Coronary Artery Bypass, Off-Pump adverse effects, Fibrinolytic Agents therapeutic use, Graft Occlusion, Vascular prevention & control, Thrombosis prevention & control
- Abstract
Background: Off-pump coronary artery bypass (OPCAB) surgery is associated with a hypercoagulable state in which the platelet thrombin receptor, protease-activated receptor-1 (PAR-1), helps propagate a thrombin burst within saphenous vein grafts. Aprotinin, used in cardiothoracic surgery mainly for its antifibrinolytic properties, also spares platelet PAR-1 activation due to thrombin. We hypothesized that this PAR-1 antagonistic property provides an antithrombotic benefit during OPCAB surgery., Methods: Patients were randomly assigned to receive saline (n = 38) or a modified full-dose regimen of aprotinin (n = 37) IV during OPCAB surgery. Blood sampled perioperatively from the coronary sinus, skin wounds, and systemic circulation was analyzed to test coagulation and platelet function. Major adverse cardiovascular events were monitored by obtaining troponin I at 24 h (myocardial infarction), predischarge computed tomography angiography (vein graft thrombosis), and by clinical examination for stroke., Results: Coronary sinus blood obtained immediately after OPCAB surgery showed significantly less activation in the aprotinin group, as judged by reduced formation of platelet-leukocyte conjugates (P < 0.02) and platelet-derived microparticles (P < 0.05). The aprotinin group showed inhibition of platelet aggregation induced by thrombin (P = 0.007) but not adenosine diphosphate. Thrombin generation, defined by F1.2 levels, was significantly reduced by aprotinin in the coronary sinus but not in skin wound incisions. Major adverse cardiovascular events were significantly reduced in aprotinin-treated patients (5.4% vs 29.7%, P < 0.05). Aprotinin also demonstrated antifibrinolytic properties through diminished red blood cell transfusion (P < 0.04) and reduced blood loss postoperatively (603 +/- 330 vs 810 +/- 415 mL, P < 0.004)., Conclusion: This study demonstrates that aprotinin protects patients undergoing OPCAB surgery from a hypercoagulable state by diminishing thrombin-induced platelet activation and thrombin generation within saphenous vein grafts, while maintaining systemic hemostatic and antifibrinolytic benefits. These results support further investigation of aprotinin and other PAR-1 antagonists in OPCAB surgery. more...
- Published
- 2009
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18. Intraoperative detection of intimal lipid in the radial artery predicts degree of postoperative spasm.
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Brown EN, Burris NS, Kon ZN, Grant MC, Brazio PS, Xu C, Laird P, Gu J, Kallam S, Desai P, and Poston RS
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- Aged, Angiography methods, Biopsy, Coronary Angiography methods, Female, Humans, Intraoperative Period, Lipids chemistry, Male, Middle Aged, Postoperative Complications, Postoperative Period, Risk, Radial Artery pathology, Radial Artery transplantation, Spasm metabolism, Spasm prevention & control, Tunica Intima pathology
- Abstract
Background: The radial artery's (RA) tendency to spasm when used as a bypass graft may relate to features of the RA itself. We imaged RA conduits before and after CABG in order to characterize intimal abnormalities that might relate to the risk of spasm., Methods: RA conduits from thirty-two CABG patients were imaged intraoperatively using catheter-based optical coherence tomography (OCT) and again on day 5 using 64-channel MDCT angiography. The change in luminal diameter between timepoints was measured in the proximal, mid and distal RA. "Spasm" was defined as focal or diffuse luminal narrowing to a diameter less than the target coronary. Lipid content in the RA was quantified by the degree of light attenuation on the OCT image., Results: Postoperative spasm was diagnosed in 18 of 32 (56%) RA grafts with the distal RA showing the most severe change versus the mid and proximal portions (-24.1+/-43.2% vs. -15.3+/-40.7%, -9.0+/-42.5% change in diameter respectively, p<0.01). The degree of attenuation of the OCT signal produced by the RA was strongly correlated with % diameter change (R=0.64, p=0.0005) and was significantly more pronounced in grafts with spasm versus no spasm (-1.97+/-0.61mm(-1) vs. -0.81+/-0.57mm(-1), p<0.0001). Histology confirmed lipid deposits in areas of RA with strong attenuation., Conclusions: RA conduits otherwise considered acceptable for bypass grafting were often found by OCT imaging to have a substantial amount of lipid, which in turn strongly relates to the risk of postoperative spasm. Screening conduits based on characteristics of intimal quality may improve results following RA grafting. more...
- Published
- 2009
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19. Prospective, observational study of antiplatelet and coagulation biomarkers as predictors of thromboembolic events after implantation of ventricular assist devices.
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Majeed F, Kop WJ, Poston RS, Kallam S, and Mehra MR
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- Adult, Aged, Biomarkers blood, Blood Platelets metabolism, Drug Resistance, Female, Fibrinolysis drug effects, Humans, Male, Middle Aged, Peptide Fragments metabolism, Plasminogen Activator Inhibitor 1 blood, Platelet Aggregation drug effects, Platelet Function Tests, Predictive Value of Tests, Prospective Studies, Prothrombin metabolism, Risk Assessment, Thrombelastography, Thromboembolism blood, Thromboembolism prevention & control, Time Factors, Aspirin therapeutic use, Blood Coagulation drug effects, Blood Platelets drug effects, Heart Failure therapy, Heart-Assist Devices adverse effects, Platelet Aggregation Inhibitors therapeutic use, Thromboembolism etiology
- Abstract
Background: Long-term success in ventricular assist device (VAD) recipients is limited by thromboembolic events, the prediction of which remains elusive. We evaluated the predictive value of aspirin hyporesponsiveness and markers of coagulation and fibrinolysis., Methods: We prospectively enrolled patients scheduled to undergo VAD implantation between June 2004 and March 2006. Once before surgery, daily during hospitalization, and weekly after discharge we assessed platelet function, measured prothrombin activation fragment 1.2 (F1.2) and plasminogen activator inhibitor-1 (PAI-1) concentrations, and evaluated aspirin hyporesponsiveness by whole-blood aggregometry and thromboelastography. All patients received 325 mg oral aspirin daily from at least 7 days before VAD implantation. Follow-up continued until heart transplantation, death or closure of the database., Results: We included 26 patients (median follow-up 315 days, range 9-833 days). In eight (31%) patients, 14 thromboembolic events occurred at a median of 42 (interquartile range 26-131) days. Only six (43%) events based on whole-blood aggregometry and one (7%) based on thromboelastography coincided with aspirin hyporesponsiveness. Within-patient variability was high for both tests (59% and 567%, respectively). Compared with levels before surgery, PAI-1 concentrations were raised for up to 45 days (P <0.0001) and those of F1.2 for up to 3 days (P = 0.0001) after VAD implantation. PAI-1 and F1.2 levels did not rise significantly further before thromboembolic events., Conclusions: Aspirin hyporesponsiveness was not associated with raised risk of future clinical thromboembolic events after VAD implantation. Impaired fibrinolysis, demonstrated by raised PAI-1 concentrations, might, however, indicate a predisposition to such events early after surgery. more...
- Published
- 2009
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20. Harmonic scalpel versus electrocautery for harvest of radial artery conduits: reduced risk of spasm and intimal injury on optical coherence tomography.
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Brazio PS, Laird PC, Xu C, Gu J, Burris NS, Brown EN, Kon ZN, and Poston RS
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- Aged, Female, Humans, Intraoperative Complications prevention & control, Male, Radial Artery anatomy & histology, Tunica Intima anatomy & histology, Vascular Patency, Coronary Artery Bypass methods, Electrocoagulation methods, Radial Artery transplantation, Spasm prevention & control, Tissue and Organ Harvesting methods, Tomography, Optical Coherence
- Abstract
Objective: Vasospasm is the primary obstacle to widespread adoption of the radial artery as a conduit in coronary artery bypass grafting. We used optical coherence tomography, a catheter-based intravascular imaging modality, to measure the degree of radial artery spasm induced by means of harvest with electrocautery or a harmonic scalpel in patients undergoing coronary artery bypass grafting., Methods: Radial arteries were harvested from 44 consecutive patients with a harmonic scalpel (n = 15) or electrocautery (n = 29). Vessels were imaged before harvesting and after removal from the arm, with saphenous vein tracts serving as internal controls. Optical coherence tomographic findings for the degree of harvesting-induced injury were validated against histologic measures., Results: Optical coherence tomographic measures of endovascular dimensions and injury correlated strongly with histologic findings. Mean luminal volume, a measure of vasospasm, decreased significantly less after harvesting with a harmonic scalpel (9% +/- 7%) than with electrocautery (35% +/- 6%, P = .015). Completely intact intima was present in 11 (73%) of 15 radial arteries harvested with a harmonic scalpel (73%) compared with 9 of 29 arteries harvested by means of electrocautery (31%, P = .011). Intraoperative flow measurements and patency rates at 5 days postoperatively were not significantly different among groups., Conclusions: Optical coherence tomography provides a level of speed and accuracy for quantifying endothelial injury and vasospasm that has not been described for any other modality, suggesting potential as an intraoperative quality assurance tool. Our optical coherence tomographic findings suggest that the harmonic scalpel induces less spasm and intimal injury compared with electrocautery. more...
- Published
- 2008
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21. Comparison of economic and patient outcomes with minimally invasive versus traditional off-pump coronary artery bypass grafting techniques.
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Poston RS, Tran R, Collins M, Reynolds M, Connerney I, Reicher B, Zimrin D, Griffith BP, and Bartlett ST
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- Aged, Coronary Artery Bypass, Off-Pump methods, Coronary Artery Disease economics, Cost-Benefit Analysis, Female, Humans, Length of Stay economics, Male, Middle Aged, Minimally Invasive Surgical Procedures methods, Prospective Studies, Quality of Life, Robotics economics, Treatment Outcome, United States, Coronary Artery Bypass, Off-Pump economics, Coronary Artery Disease surgery, Hospital Costs, Minimally Invasive Surgical Procedures economics
- Abstract
Background: Minimally invasive coronary artery bypass grafting (miniCABG) decreases in-hospital morbidity versus traditional sternotomy CABG. We performed a prospective cohort study (NCT00481806) to assess the impact of miniCABG on costs and metrics that influence quality of life after hospital discharge., Methods: One hundred consecutive miniCABG cases performed using internal mammary artery (IMA) grafting +/- coronary stenting were compared with a matched group of 100 sternotomy CABG patients using IMA and saphenous veins, both treating equivalent number of target coronaries (2.7 vs. 2.9), off-pump. We compared perioperative costs, time to return to work/normal activity, and risk of major adverse cardiac/cerebrovascular events (MACCE) at 1 year: myocardial infarction (elevated troponin or EKG changes), target vessel occlusion (CT angiography at 1 year), stroke, or death., Results: For miniCABG, robotic instruments and stents increased intraoperative costs; postoperative costs were decreased from significantly less intubation time (4.80 +/- 6.35 vs. 12.24 +/- 6.24 hours), hospital stay (3.77 +/- 1.51 vs. 6.38 +/- 2.23 days), and transfusion (0.16 +/- 0.37 vs. 1.37 +/- 1.35 U) leading to no significant differences in total costs. Undergoing miniCABG independently predicted earlier return to work after adjusting for confounders (t = -2.15; P = 0.04), whereas sternotomy CABG increased MACCE (HR, 3.9; 95% CI, 1.4-7.6), largely from lower target-vessel patency., Conclusions: MiniCABG shortens patient recovery time, minimizes MACCE risk at 1 year, and showed superior quality and outcome metrics versus standard-of-care CABG. These findings occurred without increasing costs and with superior target vessel graft patency. more...
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- 2008
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22. Is aprotinin safe to use in a cohort at increased risk for thrombotic events: results from a randomized, prospective trial in off-pump coronary artery bypass.
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Grant MC, Kon Z, Joshi A, Christenson E, Kallam S, Burris N, Gu J, and Poston RS
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- Aprotinin administration & dosage, Aprotinin blood, Blood Coagulation Tests, Follow-Up Studies, Glomerular Filtration Rate drug effects, Hemostatics administration & dosage, Hemostatics blood, Humans, Platelet Function Tests, Postoperative Complications, Prospective Studies, Aprotinin adverse effects, Coronary Artery Bypass, Off-Pump, Hemostatics adverse effects, Thrombosis etiology
- Abstract
Background: Multiple randomized trials have established a favorable safety profile for aprotinin use during cardiac surgery, but recent database analyses suggest an increased risk of adverse thrombotic events. Our group previously demonstrated that off-pump coronary artery bypass (OPCAB) is linked to a postoperative hypercoagulable state. In this study, we tested whether aprotinin influences thrombotic events after OPCAB., Methods: Patients randomly received saline (n = 61) or aprotinin (2 x 10(6) kallikrein inhibiting units (KIU) loading dose, 0.5 x 10(6) KIU/hour [n = 59]) during OPCAB. Aprotinin levels (KIU/mL) were analyzed before, and 30 minutes (peak) and 4 hours after the loading dose. Estimated glomerular filtration rate (eGFR) was calculated daily based on Cockcroft equation with acute kidney injury (AKI) defined as eGFR less than 75% of baseline. Major adverse cardiac and cerebrovascular events (MACCE) were monitored during the first year, including acute graft failure by predischarge computed tomographic angiography., Results: Compared with placebo, the aprotinin group developed a significantly lower eGFR on day 3 (p < 0.006), but this difference resolved by day 5. Peak aprotinin level correlated with the degree of eGFR decline noted on day 3 (r = 0.56, p < 0.03) and independently predicted postoperative AKI (odds ratio 8.8, p < 0.008). The receiver operating characteristic analysis demonstrated that peak aprotinin level strongly predicts AKI (area under the curve = 0.86, 95% confidence interval 0.69 to 1.00). The percentage of patients reaching the composite MACCE endpoint was significantly reduced in the aprotinin versus placebo group (12 vs 34%, p = 0.01)., Conclusions: Compared with placebo, aprotinin use was associated with less MACCE but more AKI after OPCAB. The strong relationship between the peak aprotinin level and subsequent AKI suggests weight-based protocols for dosing aprotinin may reduce this risk. more...
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- 2008
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23. Preserving and evaluating hearts with ex vivo machine perfusion: an avenue to improve early graft performance and expand the donor pool.
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Collins MJ, Moainie SL, Griffith BP, and Poston RS
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- Cold Temperature, Graft Survival, Humans, Perfusion methods, Prognosis, Tissue Donors, Heart Transplantation methods, Organ Preservation methods
- Abstract
Cardiac transplantation remains the first choice for the surgical treatment of end stage heart failure. An inadequate supply of donor grafts that meet existing criteria has limited the application of this therapy to suitable candidates and increased interest in extended criteria donors. Although cold storage (CS) is a time-tested method for the preservation of hearts during the ex vivo transport interval, its disadvantages are highlighted in hearts from the extended criteria donor. In contrast, transport of high-risk hearts using hypothermic machine perfusion (MP) provides continuous support of aerobic metabolism and ongoing washout of metabolic byproducts. Perhaps more importantly, monitoring the organ's response to this intervention provides insight into the viability of a heart initially deemed as extended criteria. Obviously, ex vivo MP introduces challenges, such as ensuring homogeneous tissue perfusion and avoiding myocardial edema. Though numerous groups have experimented with this technology, the best perfusate and perfusion parameters needed to achieve optimal results remain unclear. In the present review, we outline the benefits of ex vivo MP with particular attention to how the challenges can be addressed in order to achieve the most consistent results in a large animal model of the ideal heart donor. We provide evidence that MP can be used to resuscitate and evaluate hearts from animal and human extended criteria donors, including the non-heart beating donor, which we feel is the most compelling argument for why this technology is likely to impact the donor pool. more...
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- 2008
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24. Endovascular stenting for traumatic aortic injury: an emerging new standard of care.
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Moainie SL, Neschis DG, Gammie JS, Brown JM, Poston RS, Scalea TM, and Griffith BP
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- Adolescent, Adult, Aorta, Thoracic diagnostic imaging, Aortic Rupture diagnostic imaging, Aortic Rupture mortality, Aortic Rupture therapy, Aortography, Female, Glasgow Outcome Scale, Humans, Image Processing, Computer-Assisted, Imaging, Three-Dimensional, Injury Severity Score, Male, Middle Aged, Outcome and Process Assessment, Health Care, Risk Factors, Survival Analysis, Tomography, X-Ray Computed, Wounds, Nonpenetrating diagnostic imaging, Wounds, Nonpenetrating mortality, Aorta, Thoracic injuries, Stents, Thoracotomy, Wounds, Nonpenetrating therapy
- Abstract
Background: Thoracic aortic injury remains a leading cause of death after blunt trauma. Thoracic aortic stents have the potential to treat aortic tears using a less invasive approach. We have accumulated the largest series of patients treated with blunt thoracic aortic injury over a 2-year period., Methods: From July 2005 to present, 26 patients presenting with blunt aortic injury were treated with thoracic aortic endografting; these patients were retrospectively compared with the prior 26 patients presenting with similar aortic injury who were treated by open surgical repair. A Severity Characterization of Trauma score calculated for each patient predicts mortality based on severity of injury and degree of physiologic derangement on presentation., Results: Patients treated with endografting had a significantly shorter length of stay, less intraoperative blood loss, decreased 24-hour blood transfusion, and lower incidence of postoperative tracheostomy compared with patients undergoing open repair. Survival in both groups was similar despite a trend toward higher injury severity among patients treated with endografting., Conclusions: This early experience suggests that aortic endografting may provide a safe and efficient treatment of aortic tears that cardiac surgeons can be successful in employing. more...
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- 2008
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25. Optical coherence tomography imaging as a quality assurance tool for evaluating endoscopic harvest of the radial artery.
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Burris NS, Brown EN, Grant M, Kon ZN, Gibber M, Gu J, Schwartz K, Kallam S, Joshi A, Vitali R, and Poston RS
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- Aged, Cadaver, Cohort Studies, Coronary Disease diagnostic imaging, Coronary Disease mortality, Endoscopy methods, Evaluation Studies as Topic, Female, Humans, Male, Middle Aged, Observer Variation, Probability, Quality Control, Radial Artery pathology, Radiography, Reproducibility of Results, Risk Assessment, Sensitivity and Specificity, Survival Analysis, Vascular Patency, Coronary Artery Bypass methods, Coronary Disease surgery, Radial Artery transplantation, Tissue and Organ Harvesting methods, Tomography, Optical Coherence methods
- Abstract
Background: Concerns about intimal disruption and spasm have limited enthusiasm for endoscopic radial artery harvest (ERAH), although the risk of these problems after this procedure remains uncertain. Radial artery conduits were screened intraoperatively before and after ERAH vs open harvest using catheter-based high-resolution optical coherence tomography (OCT) imaging., Methods: Twenty-four cadavers and 60 coronary artery bypass graft (CABG) patients scheduled to receive a RA graft underwent OCT imaging before (in situ) and after (ex vivo) open harvest or ERAH. Spasm was quantified by the percentage change in luminal volume between images. Intimal disruption was classified as minor or severe depending on whether the defect was confined to branch ostia or involved the luminal surface. Histology was used to confirm OCT findings., Results: Luminal volume significantly declined after harvest in all RAs from CABG patients, but there was no difference between groups: -43% +/- 29% vs -35% +/- 38% change after ERAH (n = 21) vs open harvest (n = 39; p = 0.342). Significantly more intimal injury was noted after ERAH vs open harvest (34/41 vs 9/43, intimal tears/total evaluated RAs, p < 0.0001). Most intimal injury was minor: only 2 tears involved the luminal surface of the RA (both after ERAH). Serial imaging in cadavers revealed that 86% of ostial tears occur in ERAH during the initial blunt dissection step using the endoscope., Conclusions: Although branch injury is a pitfall of ERAH, OCT imaging documented that the quality of RA procured is acceptable and comparable with open harvest. Catheter-based OCT provides an important quality assurance tool for RA harvest. more...
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- 2008
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26. Simultaneous "hybrid" percutaneous coronary intervention and minimally invasive surgical bypass grafting: feasibility, safety, and clinical outcomes.
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Reicher B, Poston RS, Mehra MR, Joshi A, Odonkor P, Kon Z, Reyes PA, and Zimrin DA
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- Aged, Blood Coagulation Tests, Case-Control Studies, Combined Modality Therapy, Coronary Artery Bypass, Off-Pump, Coronary Disease surgery, Feasibility Studies, Female, Health Care Costs, Humans, Logistic Models, Male, Middle Aged, Minimally Invasive Surgical Procedures, Multivariate Analysis, Prospective Studies, Treatment Outcome, Vascular Patency, Angioplasty, Balloon, Coronary methods, Coronary Artery Bypass methods, Coronary Disease therapy, Drug-Eluting Stents
- Abstract
Surgical and percutaneous coronary artery intervention revascularization are traditionally considered isolated options. A simultaneous hybrid approach may allow an opportunity to match the best strategy for a particular anatomic lesion. Concerns regarding safety and feasibility of such an approach exist. We examined the safety, feasibility, and early outcomes of a simultaneous hybrid revascularization strategy (minimally invasive direct coronary bypass grafting of the left anterior descending [LAD] artery and drug-eluting stent [DES] to non-LAD lesions) in 13 patients with multivessel coronary artery disease that underwent left internal mammary artery to LAD minimally invasive direct coronary bypass performed through a lateral thoracotomy, followed by stenting of non-LAD lesions, in a fluoroscopy-equipped operating room. Assessment of coagulation parameters was also undertaken. Inhospital and postdischarge outcomes of these patients were compared to a group of 26 propensity score matched parallel controls that underwent standard off-pump coronary artery bypass. Baseline characteristics were similar in both groups. All hybrid patients were successfully treated with DES and no inhospital mortality occurred in either group. Hybrid patients had a shorter length of stay (3.6 +/- 1.5 vs 6.3 +/- 2.3 days, P < .0001) and intubation times (0.5 +/- 1.3 vs 11.7 +/- 9.6 hours, P < .02). Despite aggressive anticoagulation and confirmed platelet inhibition, hybrid patients had less blood loss (581 +/- 402 vs 1242 +/- 941 mL, P < .05) and decreased transfusions (0.33 +/- 0.49 vs 1.47 +/- 1.53 U, P < .01). Six-month angiographic vessel patency and major adverse cardiac events were similar in the hybrid and off-pump coronary artery bypass groups. A simultaneous hybrid approach consisting of minimally invasive coronary artery bypass grafting with left internal mammary artery to LAD combined with revascularization of the remaining coronary targets using percutaneous coronary artery intervention with DES is a feasible option accomplished with acceptable clinical outcomes without increased bleeding risk. more...
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- 2008
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27. Perioperative management of aspirin resistance after off-pump coronary artery bypass grafting: possible role for aprotinin.
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Poston RS, Gu J, White C, Jeudy J, Nie L, Brown J, Gammie J, Pierson RN, Romar L, and Griffith BP
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- Aprotinin therapeutic use, Blood Coagulation drug effects, Blood Coagulation physiology, Cohort Studies, Fibrinolytic Agents therapeutic use, Follow-Up Studies, Graft Survival drug effects, Hemostatics pharmacology, Hemostatics therapeutic use, Humans, Platelet Activation, Thromboplastin metabolism, Aprotinin pharmacology, Aspirin therapeutic use, Coronary Artery Bypass, Off-Pump adverse effects, Drug Resistance drug effects, Perioperative Care methods
- Abstract
Background: Aspirin is the only drug proven to reduce saphenous vein graft (SVG) failure, but aspirin resistance (ASA-R) frequently occurs after off-pump coronary artery bypass grafting (OPCAB). The factors, mechanism, and best means for preventing and/or treating ASA-R have not been established. This study hypothesizes that thrombin production during OPCAB stimulates this acquired ASA-R., Study Design and Methods: A nonrandomized prospective cohort of 255 patients (n=465 SVG) who underwent OPCAB with varied use of aprotinin (21%) and different SVG preparation techniques (standard, 56% vs. low-pressure, 44%) was analyzed. A surplus SVG segment was obtained to assess endothelial integrity. ASA-R was determined at baseline, after surgery, and on Days 1 and 3 by three assays. The effects of aprotinin on thrombin responsiveness were analyzed by means of whole-blood aggregometry, SVG tissue factor (TF) activity, and transcardiac thrombin production (i.e., F1.2 levels in aorta versus coronary sinus). SVG patency was assessed on Day 5 with multichannel CT angiography., Results: ASA-R developed in 42 percent of patients after OPCAB. Multivariate analysis showed that ASA-R, endothelial integrity, and target size independently predicted early SVG failure. Aprotinin use was associated with: 1) reduced postoperative ASA-R (15%); 2) decreased platelet (PLT) response to thrombin; 3) reduced TF activity within SVG segments; 4) decreased transcardiac thrombin gradient; and 5) improved SVG patency., Conclusion: ASA-R is a common post-OPCAB event whose frequency may be reduced by intraoperative use of aprotinin, possibly via TF and thrombin suppression. Improved perioperative PLT function after OPCAB may also inadvertently enhance the clinical relevance of these potential antithrombotic effects. more...
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- 2008
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28. Simultaneous hybrid coronary revascularization reduces postoperative morbidity compared with results from conventional off-pump coronary artery bypass.
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Kon ZN, Brown EN, Tran R, Joshi A, Reicher B, Grant MC, Kallam S, Burris N, Connerney I, Zimrin D, and Poston RS
- Subjects
- Aged, Analysis of Variance, Case-Control Studies, Cohort Studies, Coronary Angiography, Coronary Artery Bypass, Off-Pump mortality, Coronary Stenosis diagnostic imaging, Female, Follow-Up Studies, Humans, Internal Mammary-Coronary Artery Anastomosis mortality, Length of Stay trends, Logistic Models, Male, Middle Aged, Pain, Postoperative physiopathology, Pilot Projects, Postoperative Complications mortality, Probability, Risk Assessment, Sensitivity and Specificity, Severity of Illness Index, Time Factors, Tomography, X-Ray Computed, Treatment Outcome, Vascular Patency, Coronary Artery Bypass, Off-Pump methods, Coronary Stenosis mortality, Coronary Stenosis surgery, Internal Mammary-Coronary Artery Anastomosis methods
- Abstract
Objectives: Less-invasive options are available for surgical treatment of multivessel coronary artery disease. We hypothesized that stenting combined with grafting of the left anterior descending artery with the left internal thoracic artery through a minithoracotomy (hybrid procedure) would provide the best outcome., Methods: Patients with equivalent numbers of coronary lesions (2.8 +/- 0.4) underwent either hybrid (n = 15) or off-pump coronary artery bypass through a sternotomy (n = 30). Early and 1-year outcomes were compared. Blood drawn from the aorta and coronary sinus immediately postoperatively was analyzed for activation of coagulation (prothrombin fragment 1.2 and activated Factor XII), myocardial injury (myoglobin), and inflammation (interleukin 8) by using an enzyme-linked immunosorbent assay. Target-vessel patency was determined by means of computed tomographic angiographic analysis., Results: The hybrid procedure was associated with significantly shorter lengths of intubation and stays in the intensive care unit and hospital and perioperative morbidity (P < .05). Intraoperative costs were increased but postoperative costs were reduced for the hybrid procedure compared with off-pump coronary artery bypass through a sternotomy. As a result, overall total costs were not significantly different between the groups. After adjusting for potential confounders, assignment to the hybrid group was an independent predictor of shortened time to return to work (t = -2.12, P = .04). Patient satisfaction after the hybrid procedure, as judged on a 6-point scale, was greater versus that after off-pump coronary artery bypass through a sternotomy. Finally, the hybrid procedure showed significantly reduced transcardiac gradients of markers of coagulation, myocardial injury, and inflammation and a trend toward significant improvement in target-vessel patency., Conclusions: Perhaps because of reduced myocardial injury, inflammation, and activation of coagulation, patients undergoing the hybrid procedure had better perioperative outcomes and satisfaction, with excellent patency at 1 year's follow-up. These promising preliminary findings warrant further investigation of this procedure. more...
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- 2008
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29. Warm ischemia provokes inflammation and regional hypercoagulability within the heart during off-pump coronary artery bypass: a possible target for serine protease inhibition.
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Kon ZN, Brown EN, Grant MC, Ozeki T, Burris NS, Collins MJ, Kwon MH, and Poston RS
- Subjects
- Acidosis complications, Acidosis epidemiology, Aged, Aprotinin pharmacology, Aprotinin therapeutic use, Female, Graft Occlusion, Vascular blood, Humans, Intraoperative Care methods, Male, Middle Aged, Myoglobin blood, Myoglobin drug effects, Platelet Activation drug effects, Prospective Studies, Serine Proteinase Inhibitors pharmacology, Serine Proteinase Inhibitors therapeutic use, Thrombophilia blood, Thrombophilia prevention & control, Thrombosis blood, Tumor Necrosis Factor-alpha blood, Coronary Artery Bypass, Off-Pump methods, Graft Occlusion, Vascular etiology, Myocarditis etiology, Thrombophilia etiology, Warm Ischemia adverse effects
- Abstract
Objective: Accumulating evidence suggests that a hypercoagulable state influences early graft failure after off-pump coronary artery bypass (OPCAB). We hypothesized that regional myocardial ischemia caused by obligatory periods of coronary occlusion during OPCAB is an important trigger for this prothrombotic state., Methods: Using a series of biomarkers, 60 consecutive patients undergoing OPCAB were monitored for myocardial injury (myoglobin), inflammation (TNF-alpha, IL-8) and thrombosis (thrombin generation-F1.2, contact activation pathway-FXII-a, platelet derived microparticles-via flow cytometry). The transcardiac gradients of these markers were determined by assaying both arterial and coronary sinus blood just after protamine administration. Intramyocardial pH was monitored continuously during coronary occlusion in a subset (N=30 grafts, 11 patients). The influence of management strategies affecting hemostasis (e.g. antiplatelet therapy, anti-fibrinolytics, peak activated clotting time (ACT) during heparinization) was analyzed., Results: Ischemic injury, depicted by the transcardiac myoglobin gradient, significantly correlated with intramyocardial acidosis during coronary occlusion (R=0.96, p<0.0001) and predicted the transcardiac gradients of TNF-alpha (R=0.83, p<0.001) and F1.2 (R=0.72, p<0.0001). Transcardiac F1.2 strongly correlated with TNF-alpha (R=0.73, p=0.01) and IL-8 (R=0.51, p=0.02). Patients receiving aprotinin (N=20) showed significantly lower transcardiac gradients for myoglobin (4.1+/-7.5% vs 72.9+/-108.8% change, p=0.002), F1.2 (31+/-37% vs 89+/-149%, p=0.03), FXII-a (2.6+/-4.1% vs 19.2+/-34%, p=0.04) and microparticles (7+/-3.9% vs 12.9+/-8%, p=0.01)., Conclusions: Strong correlations between myocardial ischemia and the transcardiac gradients of markers for inflammation and thrombosis suggest that even brief episodes of coronary occlusion in the beating heart may have pathophysiologic consequences. Aprotinin, but not other factors that influence the coagulation system, appears to mitigate this process during OPCAB. more...
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- 2008
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30. Strategies to reduce intraluminal clot formation in endoscopically harvested saphenous veins.
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Brown EN, Kon ZN, Tran R, Burris NS, Gu J, Laird P, Brazio PS, Kallam S, Schwartz K, Bechtel L, Joshi A, Zhang S, and Poston RS
- Subjects
- Aged, Coronary Artery Bypass, Endoscopy adverse effects, Female, Humans, Male, Middle Aged, Tissue and Organ Harvesting instrumentation, Tomography, Optical Coherence, Venous Thrombosis diagnosis, Venous Thrombosis etiology, Anticoagulants therapeutic use, Heparin therapeutic use, Saphenous Vein transplantation, Tissue and Organ Harvesting adverse effects, Venous Thrombosis prevention & control
- Abstract
Objective: Residual clot strands within the excised saphenous vein are an increasingly recognized sequela of endoscopic vein harvest. We hypothesized that endoscopic visualization facilitated by sealed carbon dioxide insufflation causes stagnation of blood within the saphenous vein. In the absence of prior heparin administration, this stasis provokes clot formation., Methods: Forty consecutive patients having coronary artery bypass grafting underwent endoscopic vein harvest using sealed (Guidant VasoView, n = 30; Guidant Corp, Minneapolis, Minn) or open (Datascope ClearGlide, n = 10; Datascope Corp, Montvale, NJ) carbon dioxide insufflation followed by ex vivo assessment of intraluminal saphenous vein clot via optical coherence tomography. In the sealed carbon dioxide insufflation groups, clot formation was compared with (preheparinized, n = 20) and without (control, n = 10) heparin administration before endoscopic vein harvest, either at a fixed dose or titrated to an activated clotting time greater than 300 seconds. Risk factors for clot formation were assessed., Results: Residual saphenous vein clot was a universal finding in control veins (sealed carbon dioxide insufflation endoscopic vein harvest without preheparinization). At either dose used, heparin given before endoscopic vein harvest significantly decreased saphenous vein clot burden. A similar reduction in clot was observed when using open carbon dioxide insufflation endoscopic vein harvest without preheparinization. Intraoperative blood loss and blood product requirements were similar in all groups. Patient age and preoperative maximum amplitude of the thrombelastography tracing showed a linear correlation with saphenous vein clot volume., Conclusion: By enabling the quantification of this issue as never before possible, optical coherence tomography screening revealed that intraluminal saphenous vein clot is frequently found after endoscopic vein harvest. Systemic heparinization before harvest or an open carbon dioxide endoscopic vein harvest system are benign changes in practice that can significantly lessen this complication. more...
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- 2007
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31. The role of preexisting pathology in the development of neointimal hyperplasia in coronary artery bypass grafts.
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Kon ZN, White C, Kwon MH, Judy J, Brown EN, Gu J, Burris NS, Laird PC, Brown T, Brazio PS, Gammie J, Brown J, Griffith BP, and Poston RS
- Subjects
- Aged, Cohort Studies, Coronary Angiography, Coronary Artery Disease diagnostic imaging, Coronary Artery Disease epidemiology, Female, Follow-Up Studies, Graft Occlusion, Vascular diagnostic imaging, Graft Survival, Humans, Hyperplasia, Male, Middle Aged, Postoperative Complications diagnostic imaging, Postoperative Complications epidemiology, Postoperative Complications pathology, Risk Factors, Saphenous Vein diagnostic imaging, Saphenous Vein pathology, Tunica Intima pathology, Coronary Artery Bypass adverse effects, Coronary Artery Disease surgery, Graft Occlusion, Vascular epidemiology, Graft Occlusion, Vascular pathology, Saphenous Vein transplantation
- Abstract
Objective: Saphenous vein grafts (SVG) used for coronary artery bypass surgery (CABG) often develop a gradual luminal narrowing over the first year due to neointimal hyperplasia (NH). Although the basic science of NH is well studied, our clinical understanding of this issue is limited. The purpose of this cohort study was to investigate clinical risk factors for NH by monitoring luminal narrowing within SVG using multichannel CT angiography (CTA)., Methods: Thirty patients underwent CABG involving SVG (N = 44) and arterial grafts (N = 36). Patient variables were recorded and the baseline quality of each conduit determined intraoperatively by analyzing surplus segments for intima-media thickness ratio (IMT) by histology and matrix metalloproteinase-2 by enzyme-linked immunosorbent assay. Percent luminal narrowing (%LN) was calculated for each patent graft by comparing the CTA appearance on day 5 to a repeat study at 1 y., Results: Compared with arterial grafts, SVG showed significantly higher IMT at baseline (0.9 +/- 0.65 versus 0.22 +/- 0.17, P < 0.0001) and more %LN over the first year (6.9 +/- 7.5 versus 25.3 +/- 13.3% LN, P< 0.0001). Of all of the measured variables, the only significant predictors of %LN included baseline IMT (r = 0.58, P = 0.002) and matrix metalloproteinase-2 levels (r = 0.60, P = 0.002) in SVG., Conclusions: The degree of NH at baseline, a phenomenon exclusive to SVG and not found in arterial grafts, was significantly related to the development of lumen loss in the conduit over the first year after CABG. The study of SVG using serial CTA may provide unique insights into the natural history of SVG remodeling and to identify factors that influence the long-term function of this conduit. more...
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- 2007
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32. Thinking inside the graft: applications of optical coherence tomography in coronary artery bypass grafting.
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Brown EN, Burris NS, Gu J, Kon ZN, Laird P, Kallam S, Tang CM, Schmitt JM, and Poston RS
- Subjects
- Female, Humans, Male, Coronary Artery Bypass methods, Coronary Artery Disease pathology, Coronary Artery Disease surgery, Coronary Vessels pathology, Coronary Vessels surgery, Surgery, Computer-Assisted methods, Tomography, Optical Coherence methods
- Abstract
Recent advances in catheter-based optical coherence tomography (OCT) have provided the necessary resolution and acquisition speed for high-quality intravascular imaging. Complications associated with clearing blood from the vessel of a living patient have prevented its wider acceptance. We identify a surgical application that takes advantage of the vascular imaging powers of OCT but that circumvents the difficulties. Coronary artery bypass grafting (CABG) is the most commonly performed major surgery in America. A critical determinant of its outcome has been postulated to be injury to the conduit vessel incurred during the harvesting procedure or pathology preexistent in the harvested vessel. As a test of feasibility, intravascular OCT imaging is obtained from the radial arteries (RAs) and/or saphenous veins (SVs) of 35 patients scheduled for CABG. Pathologies detected by OCT are compared to registered histological sections obtained from discarded segments of each graft. OCT reliably detects atherosclerotic lesions in the RAs and discerns plaque morphology as fibrous, fibrocalcific, or fibroatheromatous. OCT is also used to assess intimal trauma and residual thrombi related to endoscopic harvest and the quality of the distal anastomosis. We demonstrate the feasibility of OCT imaging as an intraoperative tool to select conduit vessels for CABG. more...
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- 2007
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33. Transmyocardial Laser Revascularization Enhances Blood Flow within Bypass Grafts.
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Tran R, Brazio PS, Kallam S, Gu J, and Poston RS
- Abstract
Objective: : Early benefits from transmyocardial laser revascularization (TMR) may be related to acute sympathetic denervation. This study hypothesized that TMR as an adjunct to off-pump coronary artery bypass (OPCAB) would improve myocardial runoff in the TMR-treated regions and increase graft flow., Methods: : Graft blood flow was measured in 145 consecutive OPCAB patients. In patients with graft flow <40 mL/min (n = 25), the myocardial region served by the graft was treated with TMR. Blood flow was reassessed 10 minutes after TMR and compared with graft flow in the nontreated regions. Postoperative outcomes, transcardiac thrombin production, coagulation activation, myocardial, and inflammatory markers were assessed. A control group not treated with TMR (n = 14) was selected with similar graft flows and other baseline characteristics., Results: : Risk factors, comorbidities, and preoperative medications were similar in all groups. TMR led to a 48% increase in bypass graft flow in 12 patients, but no significant change in flow in the remainder (n = 13). The control group also showed no change in graft flow measured during the same time-points. Compared with those that did not respond to TMR, responders showed a greater drop in pH during warm ischemia caused by distal anastomoses during OPCAB and significantly higher transcardiac gradients of F1.2, IL-8, TNFα, and VCAM., Conclusions: : TMR acutely improves venous bypass graft flow in regions with more severe myocardial acidosis and inflammation during and after OPCAB. Acute sympathetic denervation after TMR may provide mechanistic insight into the early clinical benefits of TMR as an adjunct to OPCAB. more...
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- 2007
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34. Use of diffusion tensor imaging to predict myocardial viability after warm global ischemia: possible avenue for use of non-beating donor hearts.
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Collins MJ, Ozeki T, Zhuo J, Gu J, Gullapalli R, Pierson RN, Griffith BP, Fedak PW, and Poston RS
- Subjects
- Adenosine Triphosphate metabolism, Animals, Anisotropy, Biomarkers metabolism, Biopsy, Caspase 3 metabolism, Dogs, Endothelin-1 metabolism, Myocardium enzymology, Myocardium pathology, Organ Preservation, Predictive Value of Tests, Recovery of Function, Diffusion Magnetic Resonance Imaging, Heart physiopathology, Heart Arrest physiopathology, Tissue Donors, Tissue Survival, Warm Ischemia
- Abstract
Background: The assessment of myocardial viability after global warm ischemia (WI) but before reperfusion is challenging. We hypothesized that fractional anisotropy (FA), a magnetic resonance imaging (MRI) parameter of water diffusion that characterizes cellular integrity within tissues, provides a rapid and useful method for evaluating the viability of hearts after WI., Methods: Dog hearts were exposed to 60 minutes of WI after exanguination, explanted and preserved in a cold, non-beating state for 6 hours, using continuous perfusion (CP) or static cold storage (CS). Toward the end of preservation, a global FA assessment, acquired using MRI, was compared with analyses obtained from myocardial biopsies that included adenosine triphosphate (ATP), endothelin-1 (ET-1) and caspase-3 levels, light microscopy and tetrazolium staining. Functional recovery was analyzed after restoration of blood flow on a non-working Langendorff preparation., Results: FA measured at the end of CP showed strong correlations with all parameters of functional recovery (developed pressure, R = 0.60; dP/dt, R = 0.96; -dP/dt, R = 0.96). Although FA also correlated with tissue levels of ATP, ET-1 and caspase-3 (R = 0.77, -0.84, -0.64), recovery of myocardial function did not correlate with these markers or any other conventional analyses of myocardial injury (troponin I, changes on light microscopy or tetrazolium staining)., Conclusions: FA, an MRI-based parameter that indicates cellular integrity, was found to reflect better myocardial ATP stores, less induction of ET-1 and caspase-3 and improved functional recovery of hearts after global WI. As a clinically applicable tool capable of rapidly differentiating reversible from lethal injury, diffusion tensor imaging may prove useful in the eventual adoption of non-beating donor hearts for transplantation. more...
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- 2007
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35. A hybrid alternative for high risk left main disease.
- Author
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Zimrin D, Reyes PA, Reicher B, and Poston RS
- Subjects
- Aged, Combined Modality Therapy, Coronary Angiography, Coronary Stenosis complications, Diabetes Mellitus, Type 2 complications, Drug Delivery Systems, Humans, Internal Mammary-Coronary Artery Anastomosis, Male, Minimally Invasive Surgical Procedures, Peripheral Vascular Diseases complications, Pulmonary Disease, Chronic Obstructive complications, Coronary Artery Bypass, Coronary Stenosis therapy, Stents
- Abstract
Percutaneous revascularization strategies for bifurcation disease of the left main are complex and carry significant risk. These risks are magnified in the setting of a left main which trifurcates. In a patient with complex ostial disease of two of the three limbs of a left main trifurcation, turned down for conventional bypass surgery, we report on a hybrid approach for complete revascularization, consisting of minimally invasive bypass grafting of the LAD combined with simultaneous drug eluting stent placement., (Copyright (c) 2006 Wiley-Liss, Inc.) more...
- Published
- 2007
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- View/download PDF
36. Heart preservation using continuous ex vivo perfusion improves viability and functional recovery.
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Ozeki T, Kwon MH, Gu J, Collins MJ, Brassil JM, Miller MB Jr, Gullapalli RP, Zhuo J, Pierson RN 3rd, Griffith BP, and Poston RS
- Subjects
- Adenosine Triphosphate metabolism, Animals, Apoptosis physiology, Caspase 3 metabolism, Dogs, Endothelin-1 metabolism, Hydrogen-Ion Concentration, Malondialdehyde metabolism, Myocardium metabolism, Reperfusion Injury physiopathology, Reperfusion Injury prevention & control, Temperature, Ventricular Function, Left physiology, Heart physiology, Heart Transplantation methods, Organ Preservation methods, Perfusion methods, Tissue Survival physiology
- Abstract
Background: Cold static storage (CS) is a proven preservation method for heart transplantion, yet early postoperative graft dysfunction remains prevalent, so continuous perfusion (CP) during ex vivo transport may improve viability and function of heart grafts., Methods and Results: Canine hearts underwent CP (n=9) or CS (n=9) for 6 h while intramyocardial pH was continuously monitored. Biopsies were assayed for ATP, caspase-3, malondialdehyde (MDA), and endothelin-1 (ET-1) levels at baseline, after preservation (t1), and after 1 h of blood reperfusion on a Langendorff model (t2). Functional recovery was determined at t2 by +dP/dt, -dP/dt, developed pressure, peak pressure and end-diastolic pressure. CP resulted in higher tissue pH and ATP stores and reduced caspase-3, MDA and ET-1 levels compared with CS at both t1 and t2. Post reperfusion recovery was significantly greater in CP vs CS for all myocardial functional parameters except end-diastolic pressure. Weight gain was significantly increased in CP vs CS at t1, but not at t2., Conclusions: Low-grade tissue acidosis and energy depletion occur during CS and are associated with oxidative injury and apoptosis during reperfusion. CP attenuates these biochemical and pathologic manifestations of tissue injury, together with improved myocardial recovery, despite mild, transient edema. more...
- Published
- 2007
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37. Role of procurement-related injury in early saphenous vein graft failure after coronary artery bypass surgery.
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Poston RS, Kwon MH, and Gu J
- Abstract
Saphenous vein graft thrombosis after coronary artery bypass graft surgery is a poorly understood problem that lessens the benefits of this procedure. Recent studies highlight the importance of injury sustained at the time of saphenous vein graft procurement in the pathogenesis of acute graft thrombosis. In particular, damage to the graft endothelium that occurs secondary to ex vivo pressure distention, a common practice during vein harvest, leads to a loss of antithrombotic factors and increased activity of subendothelial prothrombotic factors. The prothrombotic potential of damaged grafts is further exacerbated by an ischemic storage interval and subsequent exposure to arterial flow conditions after grafting. A clearer understanding of the mechanisms by which endothelial disruption leads to acute saphenous vein graft thrombosis may result in interventions for improving our procurement techniques, interrupting the downstream effects of the damaged saphenous vein graft and/or discriminating damage that is beyond an acceptable threshold of thrombotic risk. more...
- Published
- 2006
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38. Aortic valve bypass for the high-risk patient with aortic stenosis.
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Gammie JS, Brown JW, Brown JM, Poston RS, Pierson RN 3rd, Odonkor PN, White CS, Gottdiener JS, and Griffith BP
- Subjects
- Aged, Aged, 80 and over, Aneurysm, False diagnostic imaging, Aortic Valve Stenosis physiopathology, Cardiopulmonary Bypass, Hemodynamics, Humans, Middle Aged, Postoperative Period, Retrospective Studies, Thoracotomy, Tomography, X-Ray Computed, Aortic Valve Stenosis surgery, Heart Valve Prosthesis Implantation methods
- Abstract
Background: Interest in percutaneous therapy of heart valve disease has focused attention on the high-risk patient with aortic stenosis. Aortic valve bypass (apicoaortic conduit) surgery is the construction of a vascular graft containing a bioprosthetic valve from the apex of the left ventricle to the descending thoracic aorta. We have undertaken a programmatic effort to perform aortic valve bypass surgery as an alternative to conventional aortic valve replacement in selected high-risk patients, and now report our recent experience., Methods: Between April 2003 and May 2005, 14 patients with aortic stenosis underwent aortic valve bypass surgery at two institutions. All patients selected for aortic valve bypass surgery were deemed to be at very high risk for conventional aortic valve replacement. These patients represented 14 (5.8%) of all 243 patients undergoing isolated aortic valve surgery during the same time period. Mean Society of Thoracic Surgeons predicted risk for operative mortality (11%) was between the 90th and 95th percentile., Results: Twelve of 14 patients had previous cardiac surgery with patent bypass grafts. Average age was 78 years. Mean aortic valve area was 0.68 cm2. All operations were performed through a left thoracotomy on the beating heart (cross-clamp time, 0 minutes). Cardiopulmonary bypass was used for 6 patients (median cardiopulmonary bypass time, 15 minutes). There were 2 perioperative deaths. Median postoperative length of stay was 9 days. Two noncardiac late deaths occurred. Nine of 10 surviving patients are functional class I and are living independently. Early postoperative echocardiography confirms excellent aortic valve bypass function with preservation of ventricular ejection performance., Conclusions: Treatment of high-risk aortic stenosis patients with aortic valve bypass surgery is promising. Avoidance of sternotomy and cardiopulmonary bypass supports broader application to moderate-risk patients with aortic stenosis and as a control arm for studies of novel interventional therapies. more...
- Published
- 2006
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39. Off-pump versus on-pump coronary artery bypass grafting in consecutive patients: decision-making algorithm and outcomes.
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Brown JM, Poston RS, Gammie JS, Cardarelli MG, Schwartz K, Sikora JA, Yi S, Pierson RN 3rd, and Griffith BP
- Subjects
- Aged, Comorbidity, Coronary Artery Disease mortality, Coronary Artery Disease surgery, Female, Humans, Male, Middle Aged, Prospective Studies, Risk Assessment, Treatment Outcome, Algorithms, Benchmarking, Coronary Artery Bypass mortality, Coronary Artery Bypass, Off-Pump mortality, Decision Making
- Abstract
Background: Debate continues between on-pump or off-pump approach for coronary artery bypass grafting (CABG). We used off-pump coronary artery bypass grafting (OPCAB) as a tool within a decision-making algorithm driven by the patient-related factors of coronary anatomy and comorbidity. Our analysis presents this decision algorithm and describes outcomes using this approach., Methods: From January 2000 to December 2003, 592 consecutive patients undergoing isolated CABG were assigned by one surgeon to a technique: on-pump CABG or OPCAB according to (1) anatomy and (2) predicted risk. Anatomic factors against OPCAB were target vessel size less than 1.25 mm, calcification, poor quality, intramyocardial location, and multiple stenoses. Given that OPCAB could be performed safely, patients in the moderate risk range, ie, those elderly with multiple comorbidities, were preferentially treated using OPCAB., Results: The OPCAB group had higher predicted 30-day mortality compared with the on-pump CABG group, consistent with the protocol's intent. However, morbidity and mortality were similar between on-pump CABG and OPCAB. The OPCAB patients received the same number of internal mammary artery grafts but fewer distal grafts. Mortality and observed to expected ratios were favorable for both groups and below those The Society of Thoracic Surgeons' predicted for OPCAB., Conclusions: Matching surgical strategy to patient-related factors and needs resulted in excellent outcomes. Our data support the use of a protocol based on patient characteristics to drive the surgeon's choice between an on-pump CABG or OPCAB approach. As such, OPCAB can be viewed as a tool to be used by the surgeon developing a best practice in treating coronary artery disease. more...
- Published
- 2006
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40. Aprotinin shows both hemostatic and antithrombotic effects during off-pump coronary artery bypass grafting.
- Author
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Poston RS, White C, Gu J, Brown J, Gammie J, Pierson RN, Lee A, Connerney I, Avari T, Christenson R, Tandry U, and Griffith BP
- Subjects
- Aspirin pharmacology, Biomarkers, Blood Coagulation Tests, Blood Loss, Surgical, Coronary Restenosis epidemiology, Double-Blind Method, Drug Resistance, Follow-Up Studies, Graft Occlusion, Vascular epidemiology, Humans, Myocardial Infarction epidemiology, Peptide Fragments analysis, Platelet Aggregation drug effects, Platelet Function Tests, Postoperative Complications epidemiology, Postoperative Complications prevention & control, Postoperative Hemorrhage epidemiology, Prospective Studies, Prothrombin analysis, Stroke epidemiology, Thrombelastography, Thrombin analysis, Thrombosis epidemiology, Aprotinin therapeutic use, Coronary Artery Bypass, Off-Pump, Fibrinolytic Agents therapeutic use, Hemostatics therapeutic use, Myocardial Infarction prevention & control, Postoperative Hemorrhage prevention & control, Thrombosis prevention & control
- Abstract
Background: Hemostatic drugs are widely thought to be unnecessary and potentially detrimental in off-pump coronary artery bypass graft surgery (OPCABG), despite well-established use in on-pump surgery. In a randomized, prospective OPCABG trial, we assessed efficacy and safety of aprotinin through a comprehensive assessment of graft patency and hematologic function., Methods: Sixty patients were randomly assigned to full-dose aprotinin or placebo. Heparin was titrated to a kaolin-based activated clotting time of greater than 300 seconds. Exclusionary criteria included creatinine greater than 2 mg/dL, conversion to on-pump CABG, and preoperative GPIIb/IIIa inhibition. Hematologic assessments were obtained preoperatively, at the end of surgery, and on days 1 and 3: mean platelet volume, thrombin generation (prothrombin fragment 1.2 assay), and aspirin resistance using a modified thrombelastography, whole blood aggregometry, 11-dehydro-thromboxane B2 levels, and flow cytometry. Thrombotic events were defined as postoperative myocardial infarction by electrocardiography or elevated troponin I, clinical stroke by examination and head computed tomography, and bypass graft failure by multichannel computed tomography angiography on day 5., Results: Aprotinin was associated with a significant reduction in intraoperative and postoperative blood loss compared with placebo but had no effect on transfusion rates. Patients treated with aprotinin had significantly fewer thrombotic events (3% versus 23%, p < 0.05, Fisher's exact test) and less postoperative aspirin resistance (20% versus 46%, respectively, p < 0.05, Fisher's exact test). Postoperative prothrombin fragment 1.2 level was reduced by aprotinin use., Conclusions: Aprotinin reduced perioperative bleeding after OPCABG. Preserved aspirin sensitivity in the aprotinin group may explain the observed reduction in thrombotic events and might be related to the suppression of perioperative and transmyocardial thrombin formation. more...
- Published
- 2006
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41. Off-Pump Coronary Artery Bypass Leads to a Regional Hypercoagulable State Not Detectable Using Systemic Markers.
- Author
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Kon ZN, Kwon MH, Collins MJ, Kallam S, Sangrampurkar R, Ozeki T, Brown EN, Romar LG, Pierson RN 3rd, Gammie JS, Brown JM, Griffith BP, and Poston RS
- Abstract
OBJECTIVE: It is believed that off-pump coronary artery bypass grafting (OPCAB) leads to hypercoagulability, but efforts to document such a state have been unrevealing. We hypothesized that OPCAB increases the risk of developing a regional hypercoagulable state. METHODS: Blood was obtained from the aorta and coronary sinus (CS) after CABG performed off- (N=69) or on-pump (N=35) to determine the transcardiac gradients of F1.2 (thrombin production), XIIa (coagulation activation), myoglobin (ischemia) and IL-6, IL-8 using ELISA and platelet-derived microparticles using FACS. Platelet function was measured using aggregometry. Regional myocardial pH and SVG flow were recorded intraoperatively. SVG biopsies were analyzed for endothelial integrity (EI) using immunohistochemistry and graft patency was determined by predischarge CT angiography. RESULTS: Compared with on-pump, OPCAB provoked significantly higher transcardiac F1.2 (117±200 v. 31±38%), FXII-a (14±29 v. 2±4%), microparticles (14±-9.5% v. 6.4±-4.1%), IL-6 (119±183 v. 28±39%), and a trend toward increased IL-8 (67±94 v. 24±46%, P = 0.077). Myoglobin release after OPCAB, also greater than on-pump CABG (54±89 v. 8±14%, P < 0.01), correlated with regional pH change (R=-0.96, P < 0.0001), and F1.2 release (R=0.55, P = 0.0002). In contrast, systemic changes in these markers were all less after OPCAB. SVG flow was significantly reduced in OPCAB (39.4 versus 66.5 mL/min, P = 0.0002), but EI and graft patency rates were the same. CONCLUSIONS: Through the use of transcardiac assays, we illustrated that regional coagulation was enhanced after off- compared with on-pump CABG. If the findings of this pilot study are confirmed, OPCAB may require additional antithrombotic therapies to respond to this local hypercoagulable state. more...
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- 2006
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42. Endothelial injury and acquired aspirin resistance as promoters of regional thrombin formation and early vein graft failure after coronary artery bypass grafting.
- Author
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Poston RS, Gu J, Brown JM, Gammie JS, White C, Nie L, Pierson RN 3rd, and Griffith BP
- Subjects
- Aged, Drug Resistance, Female, Humans, Male, Risk Factors, Time Factors, Treatment Failure, Aspirin therapeutic use, Coronary Artery Bypass, Off-Pump, Endothelium, Vascular pathology, Fibrinolytic Agents therapeutic use, Postoperative Complications etiology, Saphenous Vein transplantation, Thrombin biosynthesis, Thrombosis etiology
- Abstract
Objective: The predominant mechanism of early graft failure after coronary artery bypass grafting remains in doubt. Aspirin administered in the initial hours after coronary artery bypass grafting improves graft patency, implicating prostanoid synthesis in the pathogenesis. We hypothesized that synergy between endothelial disruption in the venous conduit and aspirin resistance would cause vein graft failure., Methods: Aspirin resistance, defined by diagnostic findings on at least two of three separate assays, was serially assessed in 225 patients undergoing off-pump coronary artery bypass grafting. Endothelial cell integrity was determined in surplus segments obtained from 408 vein grafts. The deposition of intraluminal thrombin within the vein was determined by comparing serum F1.2 levels between the coronary sinus and the aorta after grafting. Intraoperative blood flow in the grafts was measured with transit-time technology, and patency was assessed with electrocardiographically gated multichannel computed tomographic coronary angiography on day 5. Aspirin was the sole antithrombotic agent used during the study., Results: Thrombosed grafts (16/408) showed more endothelial cell loss at the time of grafting than did those grafts that remained patent (10.8% +/- 21.5% vs 51.4% +/- 39.1% integrity, P < .01). Aspirin resistance occurred in 67 patients (30%). Graft thrombosis was associated with aspirin resistance (P < .04) and reduced endothelial integrity (P < .01). These factors coexisted in 14 of 16 grafts that failed and were associated with elevated coronary sinus F1.2 levels., Conclusion: Aspirin resistance and relatively compromised venous endothelial cell integrity together marked patients whose vein grafts failed within days after off-pump coronary artery bypass grafting. These observations form a basis for identifying patients at risk and developing approaches to prevent vein injury or to selectively intervene in high-risk circumstances. more...
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- 2006
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43. A multi-institutional experience with the CryoMaze procedure.
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Gammie JS, Laschinger JC, Brown JM, Poston RS, Pierson RN 3rd, Romar LG, Schwartz KL, Santos MJ, and Griffith BP
- Subjects
- Adult, Aged, Aged, 80 and over, Cryosurgery instrumentation, Female, Follow-Up Studies, Humans, Male, Middle Aged, Pacemaker, Artificial, Survival Analysis, Treatment Outcome, Atrial Fibrillation surgery, Cryosurgery methods
- Abstract
Background: The Cox Maze III operation remains the gold standard for the surgical treatment of atrial fibrillation (AF). We report our experience using a flexible argon-powered metal cryoprobe for creation of the complete Cox-Maze III lesion set in patients with AF (the CryoMaze operation)., Methods: Beginning July 2002, 38 patients underwent the CryoMaze operation. Two patients had isolated CryoMaze procedures, whereas 36 patients had the CryoMaze performed in combination with coronary, valvular, or aortic surgery. All patients had electrocardiographic follow-up. Atrial fibrillation was continuous in 79%. Mean duration of AF before operation was 48 months., Results: There were no complications related to the use of cryoenergy. There was 1 hospital death (2.6%) and no late deaths. At a mean follow-up of 12 months, 35 of 37 patients (95%) were in normal sinus rhythm. One patient required pacemaker implantation 3 months after surgery, and 1 patient refused follow-up. There have been no early or late thromboembolic events., Conclusions: The CryoMaze operation reliably cures atrial fibrillation at medium term follow-up, with rates identical to those reported for the classic Cox-Maze III operation. more...
- Published
- 2005
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44. A novel approach to tricuspid valve replacement: the upside down stentless aortic bioprosthesis.
- Author
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Cardarelli MG, Gammie JS, Brown JM, Poston RS, Pierson RN 3rd, and Griffith BP
- Subjects
- Adult, Female, Humans, Male, Middle Aged, Retrospective Studies, Bioprosthesis, Heart Valve Prosthesis, Heart Valve Prosthesis Implantation methods, Tricuspid Valve Insufficiency surgery
- Abstract
Background: Tricuspid valve replacement (TVR) is a rarely needed operation. Choices between mechanical and biological prosthesis still generate controversy. We present our initial clinical experience with a stentless aortic root placed inverted in the tricuspid annulus., Methods: Between August 2000 and September 2003, TVR for severe tricuspid insufficiency was performed in 8 patients. Indications were infective endocarditis (7) and iatrogenic damage (1). Mean age was 42.2 years old (20 to 58 years old). Five patients were male and 3 patients had a concomitant procedure (mitral valvuloplasty, coronary bypass grafting, and aortic valve replacement). A stentless aortic root, size 27 mm (n = 5) or 29 mm (n = 3) was placed inverted in the tricuspid position after the valsalva sinuses were scalloped. Interrupted 4-0 polypropylene sutures were used between the tricuspid valve annulus and the sewing ring. The struts equivalent on the stentless valve were anchored to the septal, anterior and posteroinferior wall of the right ventricle using 5-0 PTFE pledgeted sutures., Results: Hospital survival was 100% and mean hospital stay was 12.5 days (3 to 18 days). Intraoperative and follow-up echocardiograms revealed no stenosis or insufficiency. Mean follow-up was 17.2 months (1-38 months). There were 3 late deaths due to continued IV drug use (n = 2) and end-stage renal failure (n = 1)., Conclusions: This is a novel surgical alternative for a very high risk population. Potential advantages over current options include minimization of blood contact with nonbiological surfaces, preservation of annular motion, freedom from anticoagulation, and a theoretical lower rate of calcification. more...
- Published
- 2005
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45. Coronary artery bypass grafts: assessment with multidetector CT in the early and late postoperative settings.
- Author
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Frazier AA, Qureshi F, Read KM, Gilkeson RC, Poston RS, and White CS
- Subjects
- Humans, Mammary Arteries transplantation, Postoperative Care, Postoperative Complications diagnostic imaging, Postoperative Complications etiology, Saphenous Vein transplantation, Time Factors, Coronary Artery Bypass adverse effects, Coronary Artery Bypass methods, Coronary Artery Disease surgery, Tomography, X-Ray Computed
- Abstract
Coronary artery bypass graft (CABG) surgery is the standard of care in the treatment of advanced coronary artery disease. It is well known that the long-term clinical outcome after myocardial revascularization depends on the patency of the bypass grafts. In the past, invasive coronary angiography was used to assess the status of the grafts and check for graft occlusion. Recently, computed tomography (CT), particularly multidetector CT with electrocardiographic gating, has emerged as an important diagnostic tool for evaluation of CABGs in both the early (< or =1 month) and late (>1 month) postoperative settings. A variety of postoperative complications may manifest as dyspnea and chest pain, thereby mimicking recurrent angina secondary to graft occlusion. Owing to its improved spatial resolution compared with that of earlier-generation CT scanners and its ability to produce three-dimensional and multiplanar images, multidetector CT has assumed an integral role in characterization of graft patency while allowing investigation of alternative postoperative complications. In addition, the expanded capabilities of volumetric imaging may provide valuable information in preoperative planning for repeat CABG surgery. more...
- Published
- 2005
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46. Disruption of graft endothelium correlates with early failure after off-pump coronary artery bypass surgery.
- Author
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Manchio JV, Gu J, Romar L, Brown J, Gammie J, Pierson RN 3rd, Griffith B, and Poston RS
- Subjects
- Aged, Anticoagulants therapeutic use, Coronary Artery Disease surgery, Female, Heparin therapeutic use, Humans, Male, Middle Aged, Platelet Activation, Risk Factors, Thrombophilia, Thrombosis etiology, Treatment Outcome, Vascular Patency, Coronary Artery Bypass, Off-Pump methods, Endothelium, Vascular physiopathology, Postoperative Complications, Saphenous Vein pathology, Saphenous Vein transplantation
- Abstract
Background: Saphenous vein graft failure after coronary artery bypass surgery may be as high as 5% to 10% in the first postoperative week. We hypothesized that identifying damage sustained by saphenous vein endothelium before grafting predicts early graft attrition after off-pump coronary artery bypass graft surgery., Methods: Intraoperative graft flow, platelet function, and endothelial integrity were analyzed in 125 patients undergoing off-pump coronary artery bypass graft surgery. Endothelial integrity was assessed in an excess vein segment from each graft using immunohistochemistry (CD31 staining). Platelet function was monitored just before and immediately after revascularization and on postoperative days 1 and 3 using whole blood aggregometry, thrombelastography, and platelet activated clotting time. Platelet activation was monitored using flow cytometry. Intraoperative conduit blood flow, measured by transit time ultrasonography, was used to detect and rectify anastomotic problems. Early graft patency was determined on postoperative day 5 using gated multichannel computed tomography angiography., Results: In 106 patients undergoing postoperative computed tomography evaluation, 10 vein grafts in 10 patients were discovered to have developed early thrombosis, representing 4% (10 of 217) of all vein grafts. Endothelial integrity was 10.75% +/- 17.56% in 10 grafts that failed early compared with 51.45% +/- 36.29% in patent grafts (p = 0.04). Perioperative platelet function and graft flow did not differ significantly between the two groups., Conclusions: Although endothelial disruption predicts early failure of bypass grafts, the importance of a hypercoaguable state and low graft flow as a cause of early graft thrombosis after off-pump coronary artery bypass graft surgery was not supported by our preliminary results. A means to assess, prevent, and treat intraoperative vein graft damage will likely improve early graft patency. more...
- Published
- 2005
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47. Myocardial reperfusion injury: etiology, mechanisms, and therapies.
- Author
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Hoffman JW Jr, Gilbert TB, Poston RS, and Silldorff EP
- Subjects
- Antioxidants metabolism, Antioxidants pharmacokinetics, Apoptosis, Endothelium, Vascular metabolism, Endothelium, Vascular physiopathology, Humans, Models, Cardiovascular, Myocardial Reperfusion Injury drug therapy, Myocardium metabolism, Myocardium pathology, Myocytes, Cardiac metabolism, Myocytes, Cardiac pathology, Neutrophil Activation, Neutrophils metabolism, Oxidative Stress, Reactive Oxygen Species metabolism, Risk Factors, Myocardial Reperfusion Injury metabolism, Myocardial Reperfusion Injury physiopathology
- Abstract
Reperfusion of ischemic myocardium is required for tissue survival; however, reperfusion elicits pathologic consequences. Myocardial reperfusion injury is a multifarious process that is mediated in part by oxygen free radicals, neutrophil-endothelium interactions, apoptosis, and intracellular calcium overload. The oxygen paradox describes the contradictory need to delivery oxygen to ischemic tissue and the resultant reduction of oxygen to form free radicals that are involved in macromolecule oxidation, membrane disfunction, apoptosis, and damaged calcium sequestering ability, which results in hypercontracture. These cell-damaging crises are amplified by the excessive activation of neutrophils, which promote the formation of proinflammatory mediators, oxygen radicals, and the reduction of endothelial nitric oxide formation, leading to increased neutrophil-endothelium interactions and capillary occlusion. Neutrophil action is twofold, however, because it is required for necrotic debris removal after severe ischemia. The oxygen radicals produced by neutrophils, endothelium, and myocytes may also play a role in activating the apoptotic cascade. Although the role of apoptosis in reperfusion injury is controversial, apoptotic cells are found in infarcted tissue. One of the key mediators may be increased inner mitochondrial membrane permeability, resulting in reduced ATP formation, release of cytochrome c, and caspase activation, which is key to promotion of apoptosis. Increased mitochondrial membrane permeability occurs during exposure to supraphysiological calcium concentrations. This occurs because of compensatory Na+/Ca2+ exchange to remove the excess intracellular sodium resulting from decreased Na+/K+ pumping during ischemia and increased Na+/H+ exchange following reperfusion. Supraphysiological calcium elicits hypercontracture and cellular damage. The various therapies being developed to diminish myocardial reperfusion injury involve inhibition of the processes described above as well as others. Although single therapies have shown some promise, the complexity of the response to reperfusion has made dramatic improvement elusive. Effective treatment will most likely require multifaceted antagonism of the numerous pathological cascades initiated by reperfusion. more...
- Published
- 2004
- Full Text
- View/download PDF
48. Optimizing donor heart outcome after prolonged storage with endothelial function analysis and continuous perfusion.
- Author
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Poston RS, Gu J, Prastein D, Gage F, Hoffman JW, Kwon M, Azimzadeh A, Pierson RN 3rd, and Griffith BP
- Subjects
- Aerobiosis, Animals, Coronary Vessels physiology, Cryopreservation statistics & numerical data, Diastole, Dogs, Endothelium, Vascular physiology, Energy Metabolism, Lactates metabolism, Myocardial Reperfusion, Myocardium metabolism, Organ Preservation statistics & numerical data, Organ Preservation Solutions pharmacology, Organ Size, Oxygen Consumption, Peroxidase analysis, Systole, Time Factors, Tissue Donors, Ventricular Function, Left, Cryopreservation methods, Heart physiology, Heart Transplantation, Organ Preservation methods
- Abstract
Background: By minimizing tissue ischemia, continuous perfusion (CP) during organ transport may increase the safety of "marginal donors." My colleagues and I investigated whether an analysis of donor heart viability predicts recovery of grafts challenged with a 24-hour preservation interval., Methods: Dog hearts underwent cold static storage (CS) for 8 hours (n = 8) or 24 hours (n = 2) or CP for 24 hours with cold asanguinous, oxygenated solution (n = 8). Myocardial systolic and diastolic function and oxygen and lactate consumption were assessed at base line, during CP, and after Langendorff blood reperfusion. Base line endothelial function was evaluated by the percentage transcoronary change ([coronary sinus - aorta]/aorta) in myeloperoxidase and by platelet function and coronary flow reserve after 20 seconds of coronary artery occlusion. During CP, the endothelium was assessed by transcoronary protein release and coronary resistance. Edema was assessed by weight gain and histology., Results: Base line systolic and metabolic functions showed no relation to post-Langendorff function. Compared with CS, CP resulted in a greater recovery in systolic function (87% +/- 35% vs 65% +/- 15% of baseline; p = 0.05) and a shorter interval required for lactate consumption to exceed production (7.0 +/- 6.8 minutes vs 15.0 +/- 8.9 minutes; p = 0.06). Endothelial function was heterogeneous: coronary flow reserve, 2.7 +/- 0.7; percentage change in myeloperoxidase, -8.4% +/- 6.8%; and change in platelet function, 4.3% +/- 3.5%, as determined by thromboelastography angle at base line. Protein release during CP for 24 hours was 8.3 +/- 7.1 g. Two factors predicted more than 75% systolic pressure generation recovery: use of CP and normal endothelial function (p = 0.05; Fisher's exact test). However, CP led to edema according to histology, weight gain (72 +/- 29 g), and impaired diastolic function versus CS (end-diastolic pressure-volume relationship, 1.4 +/- 0.4 mm Hg/mL vs 0.8 +/- 0.3 mm Hg/mL; p = 0.08)., Conclusions: Better systolic function despite 16 hours' more preservation than cold storage corroborates the idea that CP supports aerobic metabolism at physiologically important levels. Viability analysis focused on endothelial function and identified organs that were able to tolerate this 24-hour preservation interval. more...
- Published
- 2004
- Full Text
- View/download PDF
49. Heart transplantation.
- Author
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Poston RS and Griffith BP
- Subjects
- Graft Rejection prevention & control, Heart Diseases mortality, Heart Diseases therapy, Heart Transplantation mortality, Humans, Organ Preservation, Perioperative Care, Transplantation Conditioning, Heart Transplantation methods
- Abstract
Although the number of available donor hearts severely limits the epidemiologic impact of heart transplantation on patients with heart failure, patients with end-stage heart failure unresponsive to medical management currently have no other viable alternatives. Destination therapy with a ventricular assist device is the closest toward approaching clinical reality but has been plagued with problems of infection and stroke. The purpose of this review is to summarize recent developments in the field that may broaden the clinical impact of heart transplantation. For example, novel methods of cardiac preservation are being designed to safely evaluate and utilize "extended criteria" donors. Surgical techniques and medical management have reduced the incidence of postoperative right heart failure, and immunosuppressive regimens promise to limit chronic graft vascular disease. more...
- Published
- 2004
- Full Text
- View/download PDF
50. LVAD bloodstream infections: therapeutic rationale for transplantation after LVAD infection.
- Author
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Poston RS, Husain S, Sorce D, Stanford E, Kusne S, Wagener M, Griffith BP, and Kormos RL
- Subjects
- Bacteremia surgery, Device Removal, Diagnosis, Differential, Female, Humans, Male, Patient Selection, Retrospective Studies, Survival Rate, Time Factors, Treatment Outcome, Ventricular Dysfunction, Left mortality, Bacteremia diagnosis, Bacteremia etiology, Heart Transplantation, Heart-Assist Devices adverse effects, Heart-Assist Devices microbiology, Ventricular Dysfunction, Left therapy
- Abstract
Introduction: Patients who have ventricular assist devices (VADs) and experience bloodstream infection (BSI) have high mortality. We addressed 2 questions raised by the United Network for Organ Sharing (UNOS) priority policy for this problem: 1) Are organs wasted on this ultra-high-risk group? 2) Can device-related BSI be differentiated from transient BSI?, Methods: Patients with VADs who underwent heart transplantation from 1987 to 2001, who had BSI during VAD support, and who had positive cultures at VAD explant (device-related BSI, n = 10) were compared with those with negative cultures at explant (non-device-related BSI, n = 11)., Results: Patients with device-related BSI had an 80% (8/10) rate of persistent bacteremia; 30 days and 1 year after transplantation, mortality was 14% and 26%, respectively. Non-device-related BSI (n = 11) persisted in 18% (2/11); peri-operative and 1-year mortalities were 9% and 13%. Duration of VAD support predicted infection (132 vs 48 days, p < 0.001); hypo-albuminemia (2.9 +/- 0.5 mg/dl vs 3.3 +/- 0.8 mg/dl, p < 0.05), and a resistant organism predicted a device-related BSI. These patients had increased intubation requirements and had increased creatinine concentration during the first post-operative week, with no difference in liver function, blood loss, transfusions (packed red blood cells, fresh frozen plasma, or platelets), or hemodynamic stability vs patients with non-device BSI. Despite decreased immunosuppression, we found no difference in acute rejection events with device-related BSI. Re-infection with the pre-operative organism occurred in only 1 patient per group., Conclusions: These data suggest that urgent (Status 1A) cardiac transplantation is effective in stable patients with device-related BSI, and these data support the current UNOS policy. However, an extra-device source of BSI should be excluded by considering the isolated organism, the baseline nutritional status, and other risk factors. more...
- Published
- 2003
- Full Text
- View/download PDF
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