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Background: Mitral valve repair provides superior outcomes to replacement for primary mitral regurgitation. Whether this is true after previous repair is unknown. This study presents the results of a strategy of rerepair for failed mitral valve repair. The study examined patients who were brought to the operating room for an intended mitral valve rerepair., Methods: Study investigators reviewed the last decade of institutional mitral valve databases at The University of Pennsylvania (Philadelphia, PA) and Baylor Scott & White The Heart Hospital - Plano (Plano, TX) and identified patients who underwent repeat mitral valve repair, in whom the index operation was mitral valve repair. The study analyzed their operative details and the clinical and echocardiographic outcomes., Results: Between 2008 and 2021, 71 patients (aged 61.5 ±10.7 years; 20% female) underwent mitral valve reoperation at an mean of 6.24 ± 7.62 years after an index mitral repair. A total of 20% of patients presented with New York Heart Association functional class III or IV symptoms. At the index operation, 34 patients (47.9%) had repair through a right minithoracotomy. Fifteen patients (21.1%) required the reoperation within 1 year. There were 0 early and 8 late deaths. One patient who underwent mitral replacement instead of repair required reoperation for paravalvular leak during the follow-up period. Three patients required mitral valve replacement at an average of 2.28 ± 2.03 years after initial mitral valve rerepair., Conclusions: Mitral rerepair can be performed with acceptable results at a valve reference center. Durability and functional advantages of this approach remain to be proven., Competing Interests: Disclosures Wilson Szeto reports a relationship with Abbott that includes: board membership, consulting or advisory, and speaking and lecture fees. Wilson Szeto reports a relationship with Artivion, Inc that includes: board membership, consulting or advisory, and speaking and lecture fees. Wilson Szeto reports a relationship with Edwards Lifesciences Corporation that includes: board membership, consulting or advisory, and speaking and lecture fees. Wilson Szeto reports a relationship with Medtronic that includes: board membership, consulting or advisory, and speaking and lecture fees. Wilson Szeto reports a relationship with Terumo Aortic that includes: board membership, consulting or advisory, and speaking and lecture fees. Pavan Atluri reports a relationship with Edwards Lifesciences Corporation that includes: consulting or advisory. Robert Smith reports a relationship with Edwards Lifesciences Corporation that includes: consulting or advisory and funding grants. Robert Smith reports a relationship with Medtronic that includes: funding grants and speaking and lecture fees. Robert Smith reports a relationship with Artivion, Inc that includes: funding grants. Robert Smith reports a relationship with Enable CV that includes: speaking and lecture fees. All other authors, declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

Background: Minimally invasive mitral valve repair has been proven to be a safe alternative to open sternotomy and may be accomplished through classic endoscopic and robotic endoscopic approaches. Outcomes across different minimally invasive techniques have been insufficiently described. We compare early and late clinical outcomes across matched patients undergoing robotic endoscopic and classic endoscopic repair., Methods: From 2011 to 2020, 786 patients underwent minimally invasive mitral surgery, from which we were able to generate 124 matched patients (62 patients in each cohort). Clinical results were then compared between the two matched populations. Survival analysis was used to compare freedom from mortality to 10 years among matched classic endoscopic and robotic endoscopic mitral valve repair cohorts and to calculate freedom from moderate or severe mitral insufficiency at latest follow-up. Histograms of cardiopulmonary bypass (CPB) and aortic cross-clamp times were constructed, and mean bypass and cross-clamp times were compared between classic endoscopic and robotic endoscopic cohorts., Results: There was no difference in early or late mortality at 10 years in either cohort. Freedom from moderate or severe mitral regurgitation or mitral valve replacement at last echocardiogram was 86.4% vs. 73.5% at 10 years, P=0.97. Patients undergoing robotic endoscopic mitral repair had a significantly longer CPB run when compared to the classic endoscopic cohort, with 148 min of CPB in the robotic endoscopic cohort compared to 133 min in the classic endoscopic group, P=0.03. Overall post-operative length of stay was not statistically significant between the robotic endoscopic and classic endoscopic groups, 6.3±0.5 and 6.0±0.3 days, respectively. No patients in either cohort developed renal failure or wound infection. The classic endoscopic group had a slightly higher risk of prolonged ventilation when compared to the robotic endoscopic group, with three classic endoscopic patients remaining intubated >8 hours post-operatively, compared to a single patient in the robotic endoscopic group. There were no unplanned reoperations in either group. Rates of postoperative stroke were comparable between groups (three in the classic endoscopic cohort, and two in the robotic endoscopic cohort)., Conclusions: Index mitral valve surgery via a classic endoscopic approach yields similar clinical outcomes when compared to robotic endoscopic surgery. We demonstrate that both classic endoscopic and robotic endoscopic approaches allow repair of degenerative mitral valves with excellent short- and medium-term outcomes in a tertiary referral center., Competing Interests: Conflicts of Interest: The authors have no conflicts of interest to declare., (2022 Annals of Cardiothoracic Surgery. All rights reserved.)

Background: Coronary endarterectomy (CE) is an uncommon and often unplanned technique used to approach difficult targets during coronary artery bypass grafting (CABG). We evaluated the outcomes of CABG with CE (CE-CABG) using The Society of Thoracic Surgeons Adult Cardiac Surgery Database., Methods: All isolated, first-time, elective or urgent CABG cases from July 2011 to September 2019 in the Adult Cardiac Surgery Database were retrospectively reviewed. Because of a higher risk profile in the patients undergoing CE-CABG, we performed propensity score matching. Primary outcomes included operative mortality and postoperative myocardial infarction. For patients ≥65 years, long-term mortality and rehospitalization were evaluated using linked data from Centers for Medicare and Medicaid Services., Results: Of the total 1 111 792 patients included, 32 164 (2.9%) had CE-CABG and 1 079 628 (97.1%) underwent CABG alone. The majority of CE-CABG involved a single-vessel endarterectomy (86.9%; n = 27 945); the left anterior descending was most common (40.9%; n = 13 161). Compared with propensity score-matched CABG, CE-CABG had increased operative mortality (3.2% vs 1.7%; P < .0001; odds ratio, 1.81; 95% CI, 1.63-2.01) and postoperative myocardial infarction (6.8% vs 3.9%; P < .0001; odds ratio, 1.80; 95% CI, 1.68-1.93). CE-CABG had higher risk of mortality in the first year and rehospitalization for myocardial infarction in the first 3 years but was comparable to CABG alone thereafter. Subgroup analysis showed no difference between CE-CABG of the left anterior descending compared with CE-CABG of other coronary arteries., Conclusions: This analysis demonstrates that CE-CABG has acceptable long-term outcomes and serves as a benchmark for what can be expected when this rare procedure is used., (Copyright © 2022 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

In the setting of chronic primary mitral regurgitation, the benefit of mitral valve repair over replacement is well established. However, data comparing outcomes for mitral valve surgery for endocarditis is limited. We sought to determine whether mitral valve repair offers traditional advantages over replacement in the endocarditis population. Retrospective review of our institutional mitral valve database (N = 8,181) was performed between 1998 and 2019 for all adult patients undergoing isolated mitral valve surgery for endocarditis. Patients were stratified by mitral valve repair or replacement and propensity score matching was performed to adjust for differences in baseline characteristics and degree of valve damage. Overall, 267 surgeries (124 repair, 153 replacement) met inclusion criteria during the study period. Following propensity matching, the repair cohort was associated with shorter initial ventilator times (5.6 vs 7.9 hours, p = 0.05), shorter ICU (28 vs 52 hours, p = 0.03), and hospital lengths of stays (7 vs 11 days, p < 0.01). Thirty-day mortality (0% vs 2.1%, p = 0.01) and 10-year survival (88% vs 86%, p = 0.55) were similar between cohorts. Patients in the repair cohort were less likely to require repeat mitral valve intervention at our institution for recurrent endocarditis than those in the replacement cohort (0% vs 10.6%, p = 0.03). Mitral valve repair is safe, when feasible, in the setting of isolated native valve endocarditis and may provide patients faster recovery. Experienced mitral surgeons should approach this patient population with a "repair if feasible" methodology., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Objectives: Conduction disturbances requiring permanent pacemaker (PPM) implantation remain a complication following valvular surgery. PPMs confer the risk of infection, tricuspid valve regurgitation and pacing-induced cardiomyopathy. Literature examining PPM placement in mitral valve surgery (MVS) is limited., Methods: Our institutional mitral valve (MV) database was retrospectively reviewed for adult patients undergoing surgery from 2011 to 2019. Patients with preoperative PPM were excluded. Patients were stratified by the receipt of PPM following their index operations. Multivariable logistic regression was performed to determine patient and operative risk factors for PPM. Subgroup analysis was performed on patients who underwent isolated MVS. Kaplan-Meier analysis and a multivariable Cox proportional hazards model were utilized to assess the association between PPM implantation and long-term survival., Results: A total of 3391 (2991 non-PPM and 400 PPM) patients met the study criteria. Significant predictors of PPM included increased decade of age (odds ratio: 1.23; 95% confidence interval: 1.12-1.35), concomitant aortic (1.44; 1.10-1.90) and tricuspid valve procedures (2.21; 1.64-2.97) and prior history of myocardial infarction (1.48; 1.07-1.86). In the isolated MV repair population, annuloplasty with ring prosthesis was associated with PPM (3.09; 1.19-8.02). Patients in the replacement population did not have significant identifiable risk factors. There was no survival difference found, and postoperative PPM placement was not found to be an independent predictor of mortality., Conclusions: Our primary aim was to elucidate predictors for PPM implantation in MVS and found increasing age and concomitant procedures to be risk factors. Receipt of PPM is associated with worse long-term survival but does not independently predict survival. Among patients undergoing isolated MV repair, use of an annuloplasty ring confers a higher risk of PPM compared to an annuloplasty band., (© The Author(s) 2021. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

Background: Compared with conventional full sternotomy (FS) approaches, minimally invasive mitral valve surgery (MIMVS) offers improved cosmesis, decreased pain and bleeding, and faster recovery without compromising repair or survival rates. However, little is known about outcomes in patients with pulmonary hypertension (PH), an independent risk factor for morbidity and mortality., Methods: Retrospective review was performed between 2002 and 2019 for all adult patients undergoing isolated mitral valve surgery. Patients with PH (mean pulmonary artery pressure ≥25 mm Hg) were stratified by FS or MIMVS, and nearest-neighbor propensity score matching was performed to adjust for differences in baseline characteristics., Results: Overall, 591 operations (317 MIMVS, 274 FS) met inclusion criteria during the study period. Nearest-neighbor propensity matching generated 112 well-matched pairs. Cardiopulmonary bypass (137 vs 89.5 minutes, P < .001), cross-clamp (102 vs 63 minutes, P < .001), and total operative times (241 vs 178.5 minutes, P < .001) were longer for the MIMVS group. Postoperatively, MIMVS was associated with shorter initial ventilator times (6 vs 9.6 hours, P < .001) and hospital lengths of stay (7 vs 8 days, P = .049), as well as blood product usage rates (26.8% vs 41.1%, P = .03). Survival at 30 days (0.0% vs 2.7%, P = .12) and 10 years (log-rank, P = .661) were similar between groups., Conclusions: MIMVS is safe in patients with PH and provides traditional benefits of minimally invasive surgery, including shorter initial ventilator times and hospital length of stay, without compromising on long-term survival., (Copyright © 2021 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: Aortic valve replacement (AVR) for calcific aortic stenosis is associated with high rates of perioperative stroke and silent cerebral infarcts on diffusion-weighted magnetic resonance imaging (MRI), but cognitive outcomes in elderly AVR patients compared with individuals with cardiac disease who do not undergo surgery are uncertain., Methods: One hundred ninety AVR patients (mean age 76 ± 6 years) and 198 non-surgical participants with cardiovascular disease (mean age 74 ± 6 years) completed comprehensive cognitive testing at baseline (preoperatively) and 4 to 6 weeks and 1 year postoperatively. Surgical participants also completed perioperative stroke evaluations, including postoperative brain MRI. Mixed model analyses and reliable change scores examined cognitive outcomes. Stroke outcomes were evaluated in participants with and without postoperative cognitive dysfunction., Results: From reliable change scores, only 12.4% of the surgical group demonstrated postoperative cognitive dysfunction at 4 to 6 weeks and 7.5% at 1 year. Although the surgical group had statistically significantly lower scores in working memory/inhibition 4 to 6 weeks after surgery, the groups did not differ at 1 year. In surgical participants, postoperative cognitive dysfunction was associated with a greater number (p < 0.01) and larger total volume (p < 0.01) of acute cerebral infarcts on MRI., Conclusions: In high-risk, aged participants undergoing surgical AVR for aortic stenosis, postoperative cognitive dysfunction was surprisingly limited and was resolved by 1 year in most. Postoperative cognitive dysfunction at 4 to 6 weeks was associated with more and larger acute cerebral infarcts., (Copyright © 2019 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: The optimal treatment strategy following a failed mitral valve repair remains unclear. This study evaluated early and long-term outcomes of redo mitral valve repair (MVr) and replacement (MVR) after prior mitral valve repair., Methods: Patients undergoing redo mitral valve surgery after prior mitral valve repair at a single institution between 2002 and 2014 were reviewed. Primary outcomes included operative mortality (30-day or in-hospital mortality) and long-term freedom from mitral valve reoperation and death. Secondary outcomes included postoperative complications., Results: 305 patients underwent redo MVr (n = 48) or MVR (n = 257) after prior mitral valve repair. Concomitant procedures included tricuspid valve repair or replacement (23%), aortic valve replacement (6%), and coronary artery bypass grafting (4%), with no differences between cohorts. 18% were performed via right mini-thoracotomy (24% MVr vs 18% MVR, P = 0.31). Unadjusted and risk-adjusted operative mortality were lower with MVr (0% vs 8%, P = 0.04). Rates of postoperative complications were similar except for blood product transfusion (35% MVr vs 59% MVR, P = 0.003) and prolonged mechanical ventilation (8% MVr vs 29% MVR, P = 0.003). Long-term freedom from mortality was comparable: 96% MVr versus 86% MVR at 1 year and 78% MVr versus 68% MVR at 5 years (P = 0.29)., Conclusions: When technically feasible, mitral valve re-repair can be safely performed with outcomes comparable to MVR., (© 2018 Wiley Periodicals, Inc.)

Background: When valve replacement is required in patients with end-stage renal disease (ESRD), it is not clear if mechanical or bioprosthetic valve selection is better. We compared outcomes between ESRD patients who underwent either mechanical or biologic valve replacements at our institution., Methods: All patients with ESRD who underwent either mitral or aortic valve replacement from 2002 to 2014 at our institution were reviewed (n = 215; mechanical = 64, biological = 151). A Cox proportional hazards model was used to test the hypothesis that a mechanical valve was correlated with improved long-term survival. Among patients younger than 65 years (n = 123) we also compared survival with the Kaplan-Meier method., Results: Similar unadjusted survival was found for patients who received either a bioprosthetic or mechanical valve (log-rank p = 0.55). Survival is clearly attenuated in this patient population, with only about half the patients younger than 65 years surviving beyond 2 years. In the proportional hazards model, a mechanical valve was not correlated with improved survival even when controlled for other variables, including shock, endocarditis, mitral valve replacement, and patient age (95% confidence interval for hazard ratio of mechanical valve: 0.64 to 1.62)., Conclusions: It appears that there is minimal difference in survival after operation for ESRD patients who undergo bioprosthetic or mechanical valve replacement, even in patients younger than 65 years. The attenuated survival of the ESRD population after valve replacement makes the increased burden of anticoagulation (particularly in hemodialysis patients) unattractive. It is likely that only a small portion of ESRD patients benefit from the increased durability of a mechanical valve., (Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: There remains concern that moderate hypothermic circulatory arrest (MHCA) with antegrade cerebral perfusion (ACP) may provide suboptimal distal organ protection compared with deep hypothermic circulatory arrest (DHCA) with retrograde cerebral perfusion (RCP). We compared postoperative acute kidney injury (AKI) in in patients who underwent elective hemiarch repair with either DHCA/RCP or MHCA/ACP., Methods: This was a retrospective review of all patients undergoing elective aortic hemiarch reconstruction for aneurysmal disease between 2009 and 2014. Patients were stratified according to the use of DHCA/RCP versus MHCA/ACP. The primary outcome was the occurrence of AKI at 48 hours, as defined by the Risk, Injury, Failure, Loss, End-Stage (RIFLE ) criteria. A multivariable logistic regression identified risk factors for AKI., Results: One hundred eighteen patients who underwent ACP and 471 patients who underwent RCP were included. The mean lowest temperature was 26.4°C in patients who underwent MHCA/ACP and 17.5°C in patients who underwent DHCA/RCP. Baseline demographics were similar except that patients who underwent DHCA/RCP were more likely to have peripheral arterial disease or bicuspid aortic valves. Cardiopulmonary bypass and aortic cross-clamp times were shorter in the MHCA/ACP group. AKI occurred in 19 (16.2%) patients who underwent MHCA/ACP and 67 (14.3%) patients who underwent DHCA/RCP. Four (0.8%) patients who underwent DHCA/RCP required postoperative dialysis. In-hospital mortality tended to increase with increasing RIFLE classification (RIFLE class-0 (No AKI) = 0.41%; Risk = 1.35%, and Injury = 10.0%; p = 0.09). On multivariable analysis, the lowest temperature and cerebral perfusion strategy were not significant predictors of AKI. Lower baseline glomerular filtration rate (GFR), lower preoperative ejection fraction, and longer cardiopulmonary bypass (CPB) time were independently associated with higher AKI., Conclusions: We applied the sensitive RIFLE criteria to examine AKI in patients undergoing elective aortic hemiarch replacement for aneurysmal disease. Baseline renal dysfunction, lower ejection fraction, and longer CPB time are independent predictors of AKI. Compared with DHCA/RCP, our data suggest that an MHCA/ACP cerebral protection strategy does not appear to be associated with worse postoperative renal outcomes., (Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Widespread adoption of minimally invasive mitral valve repair and replacement may be fostered by practice consensus and standardization. This expert opinion, first of a 3-part series, outlines current best practices in patient evaluation and selection for minimally invasive mitral valve procedures, and discusses preoperative planning for cannulation and myocardial protection.

Minimally invasive mitral valve operations are increasingly common in the United States, but robotic-assisted approaches have not been widely adopted for a variety of reasons. This expert opinion reviews the state of the art and defines best practices, training, and techniques for developing a successful robotics program.

Techniques for minimally invasive mitral valve repair and replacement continue to evolve. This expert opinion, the second of a 3-part series, outlines current best practices for nonrobotic, minimally invasive mitral valve procedures, and for postoperative care after minimally invasive mitral valve surgery.

Objective: We describe an alternate technique for establishing antegrade cerebral perfusion (ACP) during hypothermic circulatory arrest via direct, central cannulation of the innominate artery., Methods: From 2009 to 2015, 100 elective hemiarch reconstructions for proximal aortic aneurysms were performed under moderate hypothermic circulatory arrest (MHCA). Cerebral perfusion was instituted with ACP via direct cannulation of the innominate artery., Results: Mean patient age was 63 ± 13 years (72 men; 72%). Mean MHCA temperature was 27.3°C ± 1.0°C (median, 28°C). Mean ACP time was 17 ± 4 minutes and mean crossclamp time was 134 ± 42 minutes. Proximal reconstruction included root replacement with composite valved graft (n = 47), valve sparing root reimplantation (n = 16), and aortic valve replacement (n = 19). In-hospital 30-day mortality (n = 1; 1%), stroke (1; 1%), reversible ischemic neurologic deficit (n = 1; 1%), coma (n = 0), and renal failure (n = 1; 1%) rates were low. There was no incidence of injury or dissection of the innominate artery., Conclusions: Direct, central innominate artery cannulation for ACP yields excellent outcomes. This technique is safe, provides excellent cerebral protection during circulatory arrest and simplifies the circulatory management strategy for elective ascending aortic and hemiarch reconstruction., (Copyright © 2016 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: Mitral valve surgery is increasingly performed through minimally invasive approaches. There are limited data regarding the cost of minimally invasive mitral valve surgery. Moreover, there are no data on the specific costs associated with mitral valve surgery. We undertook this study to compare the costs (total and subcomponent) of minimally invasive mitral valve surgery relative to traditional sternotomy., Methods: All isolated mitral valve repairs performed in our health system from March 2012 through September 2013 were analyzed. To ensure like sets of patients, only those patients who underwent isolated mitral valve repairs with preoperative Society of Thoracic Surgeons scores of less than 4 were included in this study. A total of 159 patients were identified (sternotomy, 68; mini, 91). Total incurred direct cost was obtained from hospital financial records., Results: Analysis demonstrated no difference in total cost (operative and postoperative) of mitral valve repair between mini and sternotomy ($25,515 ± $7598 vs $26,049 ± $11,737; P = .74). Operative costs were higher for the mini cohort, whereas postoperative costs were significantly lower. Postoperative intensive care unit and total hospital stays were both significantly shorter for the mini cohort. There were no differences in postoperative complications or survival between groups., Conclusions: Minimally invasive mitral valve surgery can be performed with overall equivalent cost and shorter hospital stay relative to traditional sternotomy. There is greater operative cost associated with minimally invasive mitral valve surgery that is offset by shorter intensive care unit and hospital stays., (Copyright © 2016 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)

Background: In patients requiring a second-time or more operation on the mitral valve (MV), we assessed whether the outcomes of the minimally invasive port access approach (port access group) were equivalent to those of the traditional redo sternotomy approach (redo sternotomy group)., Methods: In a retrospective review (1998-2011), 409 patients had previous MV operations requiring a second-time or more MV reintervention. Of those, 67 patients had the port access approach, and 342 had the redo sternotomy approach. Of the latter, 220 met the inclusion criteria because emergencies, patients with endocarditis, and those requiring concomitant procedures involving aortic valve and aorta were excluded., Results: New York Heart Association class 2 or above, age, atrial fibrillation, and surgical indications were similar in both groups. The port access group had more patients with previous MV repair (78% [n = 52] vs 41% [n = 90], p < 0.01) than with MV replacement (19% [n = 13) vs 53% [n = 116], p < 0.01). Concomitant procedures were similar (20% [n = 14] vs 27% [n = 59], p = 0.4). The MV re-repair rates were similar (19% [n = 10] vs 22% [n = 20], p = 1). The cardiopulmonary bypass times (153 ± 42 minutes vs 172 ± 83 minutes, p = 0.07) and aortic cross-clamping times (104 ± 38 minutes versus 130 ± 71 minutes, p < 0.01) were lower in the port access group. Mortality was lower in the port access group, although not significantly (3.0% [n = 2] vs 6.0% [n = 13], p = 0.5). The rates of postoperative stroke were similar (3.0% [n = 2] vs 3.2% [n = 7], p = 1). On postoperative echocardiography, freedom from mitral regurgitation >2+ was 100% in the port access group and 99% in the redo sternotomy group. The mean hospital length of stay was 11 ± 15 days versus 14 ± 12 days (p = 0.07)., Conclusions: The port access approach can be safely adopted for reoperations on the MV without compromising postoperative mortality or MV function., (Copyright © 2015 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: Deep hypothermic circulatory arrest (DHCA) with retrograde cerebral perfusion (DHCA group) has traditionally been the cerebral protection strategy during transverse hemiarch aortic reconstruction. Recently, we have adopted moderate hypothermic (≥ 25 °C) circulatory arrest (MHCA) with antegrade cerebral perfusion (MHCA group). We compared the outcomes for these two circulatory arrest management strategies., Methods: From 2008 to 2012, in a concurrent series of 376 patients (DHCA, 301; MHCA, 75) undergoing transverse hemiarch for aortic aneurysm disease, incidences of concomitant root replacement (44% vs 47%, p = 0.8), and aortic valve replacement (29% vs 21%, p = 0.3) were similar, although atherosclerotic aneurysm pathology was present in patients in the MHCA group (71% vs 33%, p < 0.01). Antegrade cerebral perfusion was established via axillary artery or direct innominate artery cannulation. A database was prospectively maintained., Results: MHCA group patients were older (66 ± 11 vs 60 ± 14 years; p < 0.01). Other demographics were similar. Aortic cross-clamp (128 ± 46 vs 163 ± 57 minutes, p < 0.01) and cardiopulmonary bypass (167 ± 49 vs 222 ± 61 minutes, p < 0.01) times were lower in the MHCA group. Transfusion requirements were significantly reduced with MHCA (38% vs 61%, p < 0.01), especially use of fresh frozen plasma and cryoprecipitate. Direct innominate artery cannulation did not result in any vascular or neurologic complication. Postoperative outcomes were similar. In-hospital and 30-day mortality was 1% in both groups. Stroke (0% vs 2%) and hemodialysis rates (0% vs 1%) were also similar., Conclusions: MHCA with antegrade cerebral perfusion yields excellent and equivalent outcomes to DHCA for elective aortic hemiarch reconstruction. MHCA significantly improves intraoperative times and, importantly, reduces transfusion requirements compared with DHCA with a retrograde cerebral perfusion strategy., (Copyright © 2015 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: Median sternotomy may be associated with postoperative complications such as nonunion after conventional metal wire closure. The Sternal Talon device (KLS Martin, Jacksonville, FL) has recently been introduced as an alternative for osteosynthesis after median sternotomy and may also be beneficial for patients with persistent sternal nonunion., Methods: A consecutive series of 24 patients underwent Sternal Talon repair for sternal nonunion or acute mediastinitis, or both, after sternal wire closure. Patient data--including demographics, surgical history, and indication for operation, as well as outcomes--were obtained and analyzed by retrospective chart review., Results: The average patient age was 61.3 years and 23 patients were men (95.8%). The most common median sternotomy procedure was coronary artery bypass grafting (CABG) in 19 patients (79.2%). Secondary closure using the Sternal Talon was indicated for sternal nonunion or infection, or both, in all patients. Eight patients underwent simultaneous muscle flap procedures during the placement of the Sternal Talon (33.3%). Sternal union was eventually achieved in 23 of 24 patients (95.8%). Subsequent reoperation was required in 4 patients (16.7%)., Conclusions: The data presented suggest that the osteosynthesis using the Sternal Talon device is a safe and effective modality for treating symptomatic sternal nonunion or acute dehiscence associated with infection (mediastinitis.)., (Copyright © 2014 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: Minimally invasive, right thoracotomy (port access) approaches to intracardiac operations (mitral valve, tricuspid valve, atrial septal defect, intracardiac tumors) are becoming increasingly accepted by surgeons, cardiologists, and patients alike. Standard techniques for cardioplegic arrest of the heart have included endoaortic balloons and Chitwood clamps. Concerns have been raised regarding the potential increased risk of vascular adverse events (embolization, dissection, stroke, lower extremity ischemia) associated with endoaortic balloon occlusion. We undertook this study to evaluate the vascular risk associated with endoaortic balloon use., Methods: All patients undergoing minimally invasive, port access, right thoracotomy operations from 1998 to 2012 at our institution were retrospectively analyzed. Patients undergoing aortic occlusion with the Chitwood clamp (n=189) were compared with patients undergoing occlusion with the endoaortic balloon (n=875)., Results: There was no statistical difference in the rate of dissection between patients undergoing aortic occlusion with an endoaortic balloon (1.03%) and those receiving a Chitwood clamp (1.06%). Similarly, there was no difference in the rate of type A dissection between aortic occlusion strategies (endoaortic balloon=0.57%, n=5, vs Chitwood clamp=1.06%, n=2, p=0.28). No difference in the incidence of stroke was identified between the endoaortic balloon and the Chitwood clamp (2.2% vs 2.1%, p=1.0)., Conclusions: Minimally invasive cardiac operations using a peripheral cannulation strategy can be safely performed with minimal vascular adverse events incorporating either endoaortic balloon or Chitwood clamp aortic occlusion. As experience with the endoaortic balloon is gained, the incidence of vascular adverse events can be reduced to nearly negligible rates., (Copyright © 2014 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: The incidence and impact of clinical stroke and silent radiographic cerebral infarction complicating open surgical aortic valve replacement (AVR) are poorly characterized., Methods and Results: We performed a prospective cohort study of subjects ≥65 years of age who were undergoing AVR for calcific aortic stenosis. Subjects were evaluated by neurologists preoperatively and postoperatively and underwent postoperative magnetic resonance imaging. Over a 4-year period, 196 subjects were enrolled at 2 sites (mean age, 75.8±6.2 years; 36% women; 6% nonwhite). Clinical strokes were detected in 17%, transient ischemic attack in 2%, and in-hospital mortality was 5%. The frequency of stroke in the Society for Thoracic Surgery database in this cohort was 7%. Most strokes were mild; the median National Institutes of Health Stroke Scale was 3 (interquartile range, 1-9). Clinical stroke was associated with increased length of stay (median, 12 versus 10 days; P=0.02). Moderate or severe stroke (National Institutes of Health Stroke Scale ≥10) occurred in 8 (4%) and was strongly associated with in-hospital mortality (38% versus 4%; P=0.005). Of the 109 stroke-free subjects with postoperative magnetic resonance imaging, silent infarct was identified in 59 (54%). Silent infarct was not associated with in-hospital mortality or increased length of stay., Conclusions: Clinical stroke after AVR was more common than reported previously, more than double for this same cohort in the Society for Thoracic Surgery database, and silent cerebral infarctions were detected in more than half of the patients undergoing AVR. Clinical stroke complicating AVR is associated with increased length of stay and mortality., (© 2014 American Heart Association, Inc.)

Objective: To determine operative outcomes of right mini-thoracotomy mitral valve surgery utilizing port access technology in first-time and reoperative cardiac surgery patients., Methods: From 2002 to 2011, 881 patients underwent minimally invasive mitral valve surgery. Of these, 154 patients had previous cardiac operations via sternotomy (Group 1), of which 18 (12%) had two previous operations. Seven hundred and twenty-seven patients had no previous cardiac operations (Group 2)., Results: Patient demographics were similar in both groups. In Group 1, 76 (49%) patients had previous coronary artery bypass grafting, 13 (8%) had previous aortic valve surgery, and 57 (37%) had previous mitral valve surgery. Preoperative echo findings for Groups 1 and 2 included severe mitral regurgitation (MR) (88%, n = 135; 94%, n = 687), mitral stenosis (MS) (4%, n = 6; 2%, n = 12), MS + MR (8%, n = 13; 4%, n = 28), and ejection fraction (48%, 56%). Operative procedures in Groups 1 and 2 were MV repair (54%, n = 84; 89%, n = 645) and MV replacement (46%, n = 70; 11%, n = 82). Circulatory management techniques for Groups 1 and 2 included endoballoon (75%, n = 116; 79%, n = 576), Chitwood clamp (8%, n = 12; 20%, n = 147), and fibrillatory arrest (17%, n = 30; 0.5%, n = 4). Perioperative outcomes were: stroke: 2.5%, 1.6%; reoperation for bleeding: 5%, 6%; valvular reoperation rate: 0.6%, 2%; aortic dissection: 2.5%, 1%; and wound infection: 0%, 0%. Transfusion requirement was 49% (n = 76) and 31% (n = 232), respectively. Median hospital stay was seven and seven days, respectively. On postoperative echocardiography, 98% (n = 151) and 99% (n = 718) of patients had zero or trace MR (1+) with 100% freedom from MR > 2+. In-hospital mortality was 3% (n = 5) and 1% (n = 8)., Conclusions: Operative outcomes with minimally invasive mitral valve surgery utilizing port access technology can be performed safely. Stroke rate was higher in the reoperative cases (p = NS) although similar to reports evaluating redo sternotomy in mitral valve cases., (© 2014 Wiley Periodicals, Inc.)

Background: Minimally invasive approaches to mitral valve repair have demonstrated equivalent technical outcomes and more rapid recovery when compared with traditional sternotomy. These techniques have been widely accepted for mitral insufficiency and stenosis. The utilization of minimally invasive techniques in the presence of left ventricular (LV) dysfunction has been controversial. We hypothesized that minimally invasive mitral valve surgery could be safely performed in the presence of compromised myocardial function, thereby minimizing recovery time., Methods: All patients undergoing minimally invasive mitral valve surgery at our center from November 1998 through June 2012 were analyzed. During this time 1,103 patients underwent minimally invasive, port access, mitral valve surgery utilizing a video-assisted limited right thoracotomy approach. Patients with LV dysfunction (ejection fraction ≤ 0.40, n = 140) were compared with patients with normal ventricular function (n = 963). Preoperative, intraoperative, and postoperative variables were compared between cohorts., Results: Patients with LV dysfunction were able to undergo mitral valve surgery with minimal mortality (2.1% vs 1.7%, p = 0.7) and morbidity, that was comparable with patients with normal ventricular function. Postoperative recovery was only slightly longer compared with patients with normal LV function as noted by time to extubation (6.0 vs 7.0 hours, p = 0.005) and hospital length of stay (7.0 vs 6.0 days, p < 0.001). A significant percentage of patients with LV dysfunction underwent redo cardiac surgery (40.0%) through minimally invasive approaches., Conclusions: Minimally invasive, port-access, mitral valve surgery can be safely performed with minimal morbidity and mortality in the presence of cardiomyopathy. This approach may be considered in patients with isolated mitral valve pathology and LV dysfunction in an experienced center., (Copyright © 2013 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Objective: To evaluate the accuracy of Doppler-derived transmitral valve gradients immediately after mitral valve repair by comparing them with near simultaneously obtained direct catheter gradients., Design: A prospective study., Setting: A tertiary care medical center., Participants: Twenty elective adult surgical patients presenting for mitral valve repair surgery., Methods: Mitral valve surgery proceeded in standard fashion except for the use of a smaller than usual left ventricular vent catheter (Medtronic DLP 10 French left heart vent catheter). After completion of the mitral valve repair and subsequent cardiac de-airing, the patient was weaned from cardiopulmonary bypass. Immediately after separation, the study period began. Near simultaneous transmitral Doppler gradients were obtained with directly measured catheter gradients via the vent catheter., Results: While the mean peak gradient difference of 1.1 mmHg was small (p-value 0.18, 95% CI: -0.54 to 2.73 mmHg), the correlation between Doppler and catheter gradient measurements (Pearson correlation coefficient r = 0.54, p = 0.055) only approached statistical significance due to the large variance associated with the small sample size. In all patients with a peak gradient greater than 10 mmHg (4 of the 20 patients), overestimation of catheter gradients by Doppler occurred, with two showing a 62% to 73% discrepancy. In these two cases, there was also evidence for elevated left ventricular end-diastolic pressure (LVEDP) along with high transmitral blood flow velocities., Conclusion: Doppler-derived transmitral gradients provide a simple, safe, and reliable measure of the true physiologic transmitral valve gradient. At the same time, it is important to recognize that significant Doppler over-estimation of catheter gradients may occur in patients with elevated Doppler transmitral velocities. The causes of these overestimations are unknown. They may be related to technical recording errors. They may also be related to an inherent weakness in Doppler technology--its inability to account for any distal recovery of pressure, which in a select group of patients could be significant., (© 2013 Wiley Periodicals, Inc.)

Objective: Minimally invasive approaches to mitral valve surgery are increasingly used, but the surgical approach must not compromise the clinical outcome for improved cosmesis. We examined the outcomes of mitral repair performed through right minithoracotomy or median sternotomy., Methods: Between January 2002 and October 2011, 1011 isolated mitral valve repairs were performed in the University of Pennsylvania health system (455 sternotomies, 556 right minithoracotomies). To account for key differences in preoperative risk profiles, propensity scores identified 201 well-matched patient pairs with mitral regurgitation of any cause and 153 pairs with myxomatous disease., Results: In-hospital mortality was similar between propensity-matched groups (0% vs 0% for the degenerative cohort; 0% vs 0.5%, P = .5 for the overall cohort; in minimally invasive and sternotomy groups, respectively). Incidence of stroke, infection, myocardial infarction, exploration for postoperative hemorrhage, renal failure, and atrial fibrillation also were comparable. Transfusion was less frequent in the minimally invasive groups (11.8% vs 20.3%, P = .04 for the degenerative cohort; 14.0% vs 22.9%, P = .03 for the overall cohort), but time to extubation and discharge was similar. A 99% repair rate was achieved in patients with myxomatous disease, and a minimally invasive approach did not significantly increase the likelihood of a failed repair resulting in mitral valve replacement. Patients undergoing minimally invasive mitral repair were more likely to have no residual post-repair mitral regurgitation (97.4% vs 92.1%, P = .04 for the degenerative cohort; 95.5% vs 89.6%, P = .02 for the overall cohort). In the overall matched cohort, early readmission rates were higher in patients undergoing sternotomies (12.6% vs 4.4%, P = .01). Over 9 years of follow-up, there was no significant difference in long-term survival between groups (P = .8)., Conclusions: In appropriate patients with isolated mitral valve disease of any cause, a right minithoracotomy approach may be used without compromising clinical outcome., (Copyright © 2013 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.)

Takotsubo cardiomyopathy is increasingly being recognized in the perioperative period. To date, there have been only three previous cases involving cardiac surgery reported and this represents the fourth case. The precise mechanism remains elusive, and there is no definitive management strategy. It appears that the syndromes course in cardiac surgical patients is self-limited. This syndrome must now be considered in the differential diagnosis of postcardiotomy cardiac failure., (© 2010 Wiley Periodicals, Inc.)

Background: The very low risk of mitral valve repair performed through median sternotomy must be reproducible when using a port-access approach to justify early repair employing minimally invasive platforms. We compared the outcomes of mitral valve repair performed through port access using thoracoscopic assistance (port) versus median sternotomy (open)., Methods: The early results after mitral valve repair performed by two different surgeons at two separate institutions were analyzed. Between January 1999 and December 2006, isolated mitral valve repair was performed with a port approach in 350 patients and an open approach in 365 patients., Results: The mean age was similar between the two groups; however, port patients were more frequently female (148 [42%] versus 119 [33%], p = 0.007), and had a higher likelihood of having New York Heart Association class III to IV symptoms (100 [29%] versus 48 [13%], p < 0.001), diabetes mellitus (19 [5%] versus 8 [2%], p = 0.023), congestive heart failure (90 [26%] versus 26 [7%], p < 0.001), and a lower ejection fraction (53% versus 64%, p < 0.001) preoperatively. Cross-clamp time (104 versus 24 minutes, p < 0.001) and bypass time (140 versus 33 minutes, p = 0.001) were significantly lower for the open group. On univariate analysis, the duration of postoperative ventilatory support was significantly lower in the port group (5.0 versus 11.0 hours, p < 0.001); however, the length of hospital stay was longer (6.95 versus 6.19 days, p < 0.001). There were 2 early deaths (2 port versus 0 open). A propensity score factor was calculated and utilized to account for differences between groups. After adjusting for propensity score and significant factors identified in multivariate models, port mitral repair independently predicted a diminished duration of postoperative ventilatory support (p = 0.045), but there were no significant differences in other outcomes including postoperative blood transfusion, reoperation for hemorrhage, or length of stay in hospital., Conclusions: Despite longer cross-clamp and bypass times, early outcomes using a thoracoscopic port-access approach were similar to those for mitral valve repair performed through median sternotomy. Minimally invasive mitral valve repair was associated with a shorter time to extubation, but that did not translate into a diminished duration of postoperative hospitalization.

Objective: To review a 2-institution experience with minimally invasive mitral valve surgery over a 12-year period., Methods: We prospectively collected data on all patients having minimally invasive mitral valve surgery through a right minithoracotomy between May 1996 and May 2008., Results: A total of 1178 patients included 941 (79.9%) patients having mitral valve repair and 237 (20.1%) having mitral valve replacement. The mean age was 61.1 +/- 13.9 years, mean ejection fraction was 52.8% +/- 12.1%, and 221 patients (18.8%) were having reoperations. Operative mortalities for mitral valve repair and mitral valve replacement were 2.1% and 4.6%, and for isolated primary MVP and MVR were 0.2% and 3.6%, respectively. Repair techniques included annuloplasty (98.2%), leaflet resection (40.7%), sliding plasty (21.0%), chordal transfer (9.0%), and neochordae placement (7.4%), with no or trivial residual MR in over 97% of patients. In patients having mitral valve replacement, a bioprosthesis was placed in 101 patients (42.6%) and a mechanical valve in 136 (57.4%). Concomitant procedures included atrial fibrillation ablation (22.5%), tricuspid valve surgery (5.4%), and atrial septal defect closure (9.4%). Nineteen patients (1.6%) experienced intraoperative conversion to sternotomy. Twenty-two patients (1.9%) had a reoperation at a mean of 732 +/- 1014 days. Independent predictors of in-hospital mortality included New York Heart Association class III/IV (odds ratio 3.62), diabetes (odds ratio 2.81), bypass time > 180 minutes (odds ratio 2.63), preoperative atrial fibrillation (odds ratio 2.53), and age > 70 years (odds ratio 2.29). Prior cardiac surgery was not a significant predictor of mortality., Conclusions: Video-assisted mitral valve surgery is safe with high rates of repair, low morbidity, and excellent outcomes. Reoperation after previous median sternotomy is not an independent predictor of mortality with this approach. Operative risk is increased if surgery is delayed until the onset of atrial fibrillation.

Background: Reoperative mitral valve (MV) surgery through sternotomy can be technically challenging. Limited exposure and injury to the right ventricle or patent grafts (previous coronary artery bypass graft surgery [CABG]) are potential complications upon sternal reentry. The purpose of this study was to examine the results of port access MV surgery through right minithoracotomy in patients with previous cardiac surgery performed through median sternotomy., Methods: From 1998 through July 2007, 651 port access MV procedures were performed. In 107 patients (16.4%), previous cardiac surgery had been performed through midline sternotomy. Mean age was 67.5 +/- 11.2 years, and 60.7% (n = 65) were male. Previous surgery included CABG (n = 45, 42.1%), aortic valve replacement (n = 9, 8.4%), aortic valve replacement/MV repair (n = 2, 1.9%), MV repair (n = 21, 19.6%), MV replacement (n = 5, 4.7%), CABG/MV replacement (n = 1, 0.9%), CABG/MV repair (n = 8, 7.5%), CABG/aortic valve replacement (n = 2, 1.9%), and others (n = 14, 13.1%). New York Heart Association functional classes were I (n = 2, 1.9%), II (n = 28, 26.2%), III (n = 50, 46.7%), and IV (n = 27, 25.2%). The endoaortic balloon was used in 75 patients (70.1%) and the Chitwood clamp in 11 patients (10.2%). In the remaining patients (n = 21, 19.6%), fibrillatory arrest was employed., Results: Mitral valve repair and MV replacement were performed in 60 patients (56.1%) and 47 patients (43.9%), respectively. The 30-day mortality was 4.7% (n = 5). The mean cardiopulmonary bypass and aortic cross-clamp times were 140.8 +/- 43.7 minutes and 77.0 +/- 49.7 minutes, respectively. Complications included 6 reoperations for bleeding (5.6%), 1 stroke (0.9%), and 2 wound infections (1.9%). Conversion to sternotomy was required in 1 patient (0.9%) because of an acute type A dissection secondary to aortic occlusion with Chitwood clamp. The mean hospital stay was 9.6 days. During follow-up, reoperation for failure of MV repair was performed in 4 patients (3.7%)., Conclusions: Reoperative port access MV surgery can be performed with minimal morbidity and mortality. This approach may be the preferred technique for patients who require MV procedures after previous cardiac surgery performed through median sternotomy.

Background: Reoperative aortic root reconstruction is increasingly performed and remains a clinical challenge. The aim of this study is to evaluate the outcome of patients undergoing reoperative aortic root replacement after previous aortic surgery., Methods: From 1995 to 2006, 156 consecutive patients underwent reoperative aortic root replacement after previous aortic valve replacement (group 1, n = 106, 67.8%), proximal aortic reconstruction (group 2, n = 25, 16.1%), and aortic root replacement (group 3, n = 25, 16.1%). Their records were retrospectively reviewed., Results: The mean age was 58.1 +/- 14.4 years, and 73.7% (n = 115) were men. Reoperation was performed 98.4 months after previous operation, with 14.7% (n = 23) having undergone three or more sternotomies. Indications for reoperations were endocarditis in 55 (35.3%), prosthetic valve dysfunction in 28 (17.9%), paravalvular leak in 12 (7.7%), aortic aneurysm or pseudoaneurysm in 29 (18.5%), aortic dissection in 12 (7.7%), and aortic stenosis or insufficiency in 20 (12.9%). Aortic root replacement was performed in all 156 patients, with concomitant hemiarch reconstruction in 62 (39.7%), Cabrol coronary reconstruction in 5 (3.2%), coronary artery bypass grafting (CABG) in 26 (16.6%), and mitral valve repair or replacement (MVR) in 25 (16.0%). Thirty-day mortality was 11.5% (n = 18). Actuarial survival was 86.4% +/- 2.7% at 1 year, 72.6% +/- 4.3% at 5 years, and 58.4% +/- 7.8% at 10 years. Subgroup analysis demonstrated no difference in 30-day mortality (group 1, 14.1%; group 2, 8.0%; group 3, 4.0%; p = 0.31) and late survival between the three groups (p = 0.14). Multivariate analysis demonstrated age older than 75 years (p = 0.03) and New York Heart Association (NYHA) functional class IV (p = 0.05) as risk factors for 30-day mortality., Conclusions: Reoperative aortic root reconstruction can be performed with a low perioperative mortality rate and satisfactory long-term survival. Age older than 75 years and NYHA class IV are risk factors for early mortality. Previous aortic root replacement is not a risk factor for reoperative aortic root reconstruction.

The immediate effect or mitral valve repair (MVP) or replacement (MVR) on cardiac function was compared in patients with mitral regurgitation in relation to the changes in left ventricular (LV) function and geometry by using intraoperative transesophageal echocardiography in 29 patients with MVP and 21 patients with MVR, before and immediately after cardiopulmonary bypass. The LV volumes, ejection fraction, and long-axis and short-axis lengths and eccentricity index (ratio of long axis to short axis) at end-systole and end-diastole were measured. After both MVP and MVR, there were significant decreases in LV end-diastolic volume (p < 0.0001). However, the ejection fraction did not change after MVP, whereas it decreased after MVR (p < 0.0001). After MVP, there was an increase in eccentricity index at end-systole (p < 0.0001). After MVR, there was no decrease in end-systolic volume, and the eccentricity index was lower than that after MVP (p < 0.0001). The change in LV ejection fraction correlated with the changes in eccentricity index at end-systole (r = 0.55; p < 0.0001) and end-diastole (r = 0.42; p < 0.0003). Immediate intraoperative LV function is preserved after MVP but is depressed after MVR for mitral regurgitation. The changes in ejection fraction correlate with changes in ventricular geometry.

Background: Patients with sustained ventricular tachycardia after acute myocardial infarction frequently have characteristic abnormalities of left ventricular endocardial electrical activity, including fractionated (prolonged, multicomponent, low-amplitude), split (having discrete widely separated deflections), and late (extending after the end of the QRS complex) electrograms. The exact cause and source of these electrograms are not clear., Methods and Results: In this study, endocardial electrograms from 18 patients were recorded with a 20-electrode array from the same area immediately before and immediately after resection of subendocardial tissue at the time of surgery for ventricular tachycardia. Electrograms could be compared before and after resection from 298 of 360 (83%) of the electrodes. Before resection, split electrograms were present in 130 (44%) and late components in 81 (27%) of the recordings. Recordings made after resection showed fewer abnormalities, including complete absence of split electrograms as well as all previously recorded late components (P < .02). Mean electrogram amplitude increased from 0.5 +/- 0.8 to 1.0 +/- 1.6 mV (P < .0001) because of removal of the attenuating effect of endocardial scar; mean duration decreased from 112 +/- 38 to 65 +/- 27 ms (P < .0001) mainly because of loss of late and split components. Overall electrogram contour was very similar aside from these changes., Conclusions: These data show that (1) some of the signal recorded on the endocardial surface is derived from deeper tissue layers and (2) split and late electrogram components appear to be generated by cells in the superficial endocardial layers, since they are eradicated by removal of this tissue. These findings correspond well with previous histological studies of resection specimens that show bundles of surviving muscle cells separated by layers of dense scar that act as an insulator.

Sustained ventricular tachycardia with left ventricular aneurysm formation is a rare complication following penetrating cardiac trauma. We present an unusual case of serious ventricular tachycardia which developed 35 years after a World War II injury and was successfully treated with aneurysmectomy, map-guided subendocardial resection, and cryoablation.

Two patients with isolated transmural ischemic necrosis of the cecum after cardiopulmonary bypass are discussed. Superimposed upon the multiple cardiovascular abnormalities in these patients, cardiopulmonary bypass adds another risk factor for nonocclusive intestinal infarction. In patients undergoing open-heart procedures, postoperative nonspecific abdominal complaints should be evaluated with a high degree of suspicion for this lethal complication. An intensive diagnostic effort is indicated, including contrast and angiographic radiological studies. Consideration of early abdominal exploration is indicated.

To determine the relation between the intraoperative defibrillation threshold and successful postoperative termination of induced ventricular fibrillation (VF) with the automatic implantable cardioverter defibrillator (AICD), 33 patients who underwent AICD implantation were studied. The defibrillation threshold, determined after at least 10 seconds of VF, was 5 J in 2, 10 J in 6, 15 J in 10, 20 J in 10 and 25 J in 5 patients. The AICD energy rating on the first discharge was 28 +/- 1.8 J. Defibrillation of induced VF was demonstrated postoperatively in 29 of 33 (88%) patients. The AICD terminated VF postoperatively in all 18 patients with a defibrillation threshold less than or equal to 15 J. Only 11 of the 15 (73%) patients with a defibrillation threshold greater than or equal to 20 J (p less than 0.04) had VF terminated postoperatively. In all 4 patients in whom the AICD failed to terminate induced VF, the energy difference between the AICD rating and the defibrillation threshold was less than or equal to 10 J. Among the 14 patients with a difference of less than or equal to 10 J between the AICD energy rating and the defibrillation threshold, there were no significant differences between the 4 patients with and the 10 without successful VF termination with respect to the duration of VF induced postoperatively or the AICD lead system. In summary, failure to terminate VF with the AICD is not uncommon (27%) when the defibrillation threshold approaches the energy delivering capacity of the AICD.(ABSTRACT TRUNCATED AT 250 WORDS)

We studied the effect of parenteral nutrition with amino acids and hypertonic glucose on protein synthesis and liver fat metabolism. Patients with operable gastrointestinal tract malignancies were divided into two groups. Group I ate the hospital diet ad libitum for the 7-10 days preceding surgery. Group II were given adjuvant parenteral nutrition (APN) for 7-10 days prior to the surgical removal of the tumor. Daily nutrient intake and nitrogen balance were determined. [15N[glycine (1-2 g) was infused at a constant rate for 12-18 prior to surgery. During surgery, blood, liver, and muscle specimens were taken for 15N analysis. Fractional protein synthesis rates were estimated by the method of Garlick et al. (Biochem. J. 136: 935-945, 1973). The fat content and distribution pattern in the liver was determined by gas chromatography-mass spectrometry. The following results were found. 1) APN increaed the albumin synthesis rate. 2) The fraction of linoleate in the total liver fatty acids were reduced by 75% in the APN patients. 3) Some of the APN patients developed fatty livers during the study. When the APN patients were subdivided on the basis of whether they had fatty livers, it was found that only those patients who did not accumulate fat showed an improvement in their plasma albumin concentration during the period of parenteral nutrition.

In 28 Dorsett sheep, ligation of the distal homonymous (equivalent to human left anterior descending) and second diagonal coronary arteries produced a constant transmural infarct of 22.9% +/- 2.5% (mean +/- standard deviation) of the left ventricular mass. Serial left ventriculograms showed that within four hours the infarct segment expands, wall thickness decreases, and aneurysmal dilatation occurs and progresses over the next 60 days in all sheep. Epicardial ventricular point references indicated that adjacent noninfarcted myocardium participates in the formation of the aneurysm. Anatomy of the coronary vasculature was studied in 22 excised sheep hearts. In sheep, coronary arterial anatomy is remarkably constant. The left coronary artery provides all of the blood supply to the left ventricle and septum and only a small rim of both the anterior and posterior right ventricles. Cardiac veins from the left ventricle drain into the coronary sinus, which also receives the left azygos vein. Right ventricular veins drain separately. The essentially separate coronary circulations to the two ventricles, the paucity of coronary collateral circulation, and the consistent evolution of left ventricular infarcts into aneurysms are important advantages of the ovine model for both metabolic and ventricular mechanical studies of acute myocardial infarction and left ventricular aneurysm.

Subendocardial resection and implantation of an automatic implantable cardioverter/defibrillator are the current preferred treatments for the management of drug-resistant malignant ventricular arrhythmias and sudden cardiac death. We reviewed retrospectively the case histories of 269 patients who had subendocardial resection and 77 patients who had defibrillator implantation to define clinical characteristics of each group and compare operative and long-term results. All patients treated by subendocardial resection had recurrent sustained ventricular tachycardia as a result of a myocardial infarction. From the standpoint of arrhythmia substrate and cardiac disease, patients receiving the defibrillator were a more heterogeneous group. Forty-eight (62%) had coronary artery disease, 28 (36%) cardiomyopathy, and one patient had a primary electrical abnormality. Among patients receiving the defibrillator, 55% had sustained ventricular tachycardia and 45% polymorphic ventricular tachycardia or ventricular fibrillation. Overall ventricular function was similar in the two groups. Operative mortality rate was better in the group having defibrillator implantation (3% versus 15%). Complications related to the defibrillator device or implantation occurred in 46 (60%) patients, with asymptomatic shocks occurring in 35 patients (45%). Since the defibrillator was not designed to prevent arrhythmias, the arrhythmia-free survival rate was much better in the group having subendocardial resection (95% versus 44% at 3 years). Fewer patients treated by subendocardial resection required antiarrhythmic medications (33% versus 66%). The actuarial survival rate was similar in the two groups (approximately 60% at 4 years), with heart failure the most common cause of death. Thus both subendocardial resection and defibrillator implantation are highly effective in preventing sudden cardiac death. The choice of procedure depends on (1) arrhythmia diagnosis, (2) cardiac disease, and (3) intangible factors.

Fractional protein synthesis rates of tumor, normal intestinal tissue, liver, and fibrinogen were measured in a series of patients with gastrointestinal malignancies. Protein synthesis rates were measured by the continuous infusion of 95+% [15N]glycine. Twelve to eighteen hours prior to the clinically indicated surgical excision of the tumor, 1-2 g of 95+% [15N]glycine was infused at a constant rate into each subject. During the surgical procedure, 0.05-2 g of tumor, normal intestinal tissue, liver, and 30 ml of venous blood were obtained. Protein synthesis rates were estimated from the ratio of 15N incorporated into tissue protein to the 15N enrichment of the tissue-free amino acid pool. The major findings were: i) the 15N enrichment of the tissue-free amino acids in malignant tissue was greater than and proportional to that in the corresponding normal tissue (P less than 0.02); ii) tumor protein synthesis rates were greater and proportional to the corresponding intestinal tissue rates (P less than 0.05); iii) the fibrinogen synthesis rate was greater than the liver protein synthesis rate (P less than 0.01), but there was no correlation between them.

Forty-three patients with sustained ventricular tachycardia (VT) caused by prior myocardial infarction underwent intraoperative endocardial activation mapping during a total of 122 episodes of VT. Electrograms obtained during mapping were analyzed to determine the prevalence of local conduction failure during VT (defined as a portion of the local electrogram that did not repeat with every tachycardia cycle). Local conduction failure during VT was observed in 37 (86%) patients and 73 (65%) tachycardias. VT in which local conduction failure was observed were faster than VTs without local conduction failure (cycle length 315 vs 345 msec; p less than .05). Local conduction failure occurred most frequently at or near sites having the earliest recorded electrical activity during VT ("site of origin"). Twenty-three patients also had sinus rhythm endocardial mapping at the time of surgery. Areas with abnormal or fractionated electrograms in sinus rhythm were more likely to demonstrate local conduction failure in VT than areas with normal electrograms in sinus rhythm (16% vs 8%; p less than .01). Although the mechanism responsible for local conduction failure in VT is unclear, it is a common occurrence and is significant in that it can occasionally mimic "early" sites of endocardial activation, unless enough VT cycles are observed at a given site.

Seventeen patients with acute peripheral arterial or graft occlusion were treated with local low-dose intra-arterial streptokinase. The series includes eight patients with native vessel occlusion, six patients with vein graft occlusion, two patients with prosthetic graft occlusion, and one patient with renal allograft artery occlusion. The duration of occlusion prior to streptokinase therapy varied from 2 hours to 5 weeks. The treatment was successful in 14 of the 17 instances. In conjunction with the successful thrombolytic therapy, percutaneous transluminal angioplasty was performed subsequently in 10 of the patients and reconstructive surgery in three. One major and five minor hemorrhagic complications occurred and were considered to be secondary to the streptokinase therapy. In follow-up of up to 9 months, 11 of the 14 successfully treated patients continued to have a good result, without any indication of recurrent arterial occlusion. Two patients have died of causes unrelated to thrombolytic therapy and one patient required bypass grafting for recurrent thrombosis. None of the successfully treated patients lost a limb. Of the three patients in whom thrombolysis was unsuccessful, two required amputation. Local intra-arterial low-dose streptokinase appears to be a promising alternative to immediate operative treatment in carefully selected cases of arterial occlusion. Definitive treatment of the underlying cause of the thrombus usually is required and changes of success may be enhanced by the thrombolytic therapy.

Ventricular tachycardia associated with inferior wall myocardial infarction has had a lower surgical cure rate with localized subendocardial resection than ventricular tachycardia related to anterior infarction. Some investigators have advocated visually directed extensive subendocardial resection, including resection of the papillary muscles and mitral valve replacement, even without documenting the origin of ventricular tachycardia at these sites. We have operated on 46 patients (43 men and three women) for ventricular tachycardia associated with inferior wall myocardial infarction. Thirty-one consecutive patients (Group I) had standard localized subendocardial resection. Two patients in this group had mitral valve replacement for mitral insufficiency. Fifteen consecutive recent patients (Group II) underwent subendocardial resection plus focal endocardial cryoablation (3 minutes at -70 degrees C) of the annular isthmus. The annular isthmus is defined as the ventricular muscle between the basal end of the ventriculotomy and the mitral valve anulus. In Group I there were four operative deaths (13%). Ventricular tachycardia was noninducible in 15 of 27 operative survivors (56%) at postoperative electrophysiologic studies. In Group II there was one operative death (7%) and 13 of 14 survivors (93%) had no inducible ventricular tachycardia at postoperative electrophysiologic studies (p less than 0.01 versus Group I). No Group II patient required mitral valve replacement. Six operative survivors in Group II had intraoperative activation maps consistent with macroreentry incorporating the annular isthmus. Group I and Group II were indistinguishable in terms of preoperative hemodynamics, number of coronary arteries diseased, or the presence of left ventricular aneurysm. These results suggest that subendocardial resection with additional cryoablation of the annular isthmus results in improved control of ventricular tachycardia in patients with ventricular tachycardia associated with inferior wall myocardial infarction. Mitral valve replacement is not required unless intrinsic mitral valve disease is present. These data also suggest that the annular isthmus is a critical component of the reentrant circuit in these tachycardias.

Twenty-seven endocardial cryolesions were created in mongrel dogs and analyzed to determine the effects on cryolesion size of both the initial myocardial temperature (37 degrees C versus 12 degrees C) and the pressure within the nitrous oxide delivery line (tank pressure of more than 700 pounds per square inch [psi] versus tank pressure of less than 700 psi). In addition, local myocardial temperatures were monitored to determine their utility in the intraoperative determination of the extent of cryothermic cell death. Cryolesion volume was significantly affected by both the initial myocardial temperature (p less than 0.001) and the line pressure (p = 0.014). In a 37 degrees C myocardium, the mean lesion volume ranged from 0.501 +/- 0.183 cc at line pressures lower than 700 psi to 0.839 +/- 0.258 cc at line pressures greater than 700 psi. In a 12 degrees C myocardium, the mean volume was 1.151 +/- 0.436 cc at line pressures lower than 700 psi and 1.361 +/- 0.288 cc at line pressures higher than 700 psi. A myocardial temperature of 0 degrees C occurs at the edge of the area of cell death. When analyzing the range from -5 degrees to +5 degrees C, the probability of a point at or lower than 0 degrees C falling inside the cryolesion is 84.2%. Monitoring intramyocardial temperature will predict the border of a cryolesion.