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Background: Long-term (>30 days) esophageal stenting is controversial. Previous studies have documented complications associated with long-term esophageal stent use. This study's objective was to investigate complications associated with long-term esophageal stent use., Methods: A retrospective review of stenting done by thoracic surgery for any reason between 2010-2020 was completed. Patients were included if they had at least 30 days of follow-up after their initial stent placement. Outcomes included stent dwell time, patient outcomes, procedural and stent-related complications., Results: Fifty-six patients, with 25 having ≥2 stents placed were included; overall, 90 stents were placed. The median length of initial esophageal stent dwell time was 59 [interquartile range (IQR), 21-119] days. Stent migration was the most common complication and occurred more with benign indications (P=0.12). As the length of dwell time increased, prevalence of any complication decreased. Complication rates between short-term (<30 days) and long-term stents were not significantly different (P=0.39). No instances of esophageal perforation or aortoesophageal fistulas related to stents were identified. There was one instance of post-esophagectomy tracheoesophageal fistula which was managed successfully with prolonged stenting., Conclusions: Over a 10-year period, there were no instances of stent erosion into the aorta or esophageal perforation, and the most frequent stent-related complication was stent migration. Long-term esophageal stenting did not result in increased rates of stent related complications in our cohort. This case series demonstrates that long-term stents may be safely used for many different indications. Randomized controlled studies may be needed to validate these findings., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form, except for author B.M.B., who is deceased (available at https://jtd.amegroups.com/article/view/10.21037/jtd-24-366/coif). K.F.L.U. reports that he holds positions in two local medical societies (Treasurer, Philippine Medical Association of New England and Committee Member, Worcester District Medical Society), which do not impact this work. The other authors have no conflicts of interest to declare., (2024 Journal of Thoracic Disease. All rights reserved.)

Background: Although robotic surgery has gained popularity, safety concerns remain due to potential delay in addressing intraoperative hemorrhages since the surgeon is not at the bedside. This study aimed to test whether a training program for emergency robotic undocking protocols improved the performance of thoracic operating room (OR) teams., Methods: An emergency undocking protocol and checklists were created for massive hemorrhage during robotic thoracic surgery. In phase I, two OR teams participated in in-situ simulations of the scenarios in the OR without knowledge of the protocols. In phase II, the protocol and checklists were introduced to four different OR teams by either high-fidelity lab simulation or video-based didactic sessions. The teams' performances were tested with in-situ OR simulations. Performance assessments included the number of missed critical steps, participant-reported feedback, and timeliness of crucial steps., Results: All teams successfully converted from robot-assisted to open, with the attending at bedside within five minutes from the decision to convert, regardless of phase or education type. Phase I (control) teams had an average of 2.55 critical misses per team while the average was 0.25 for phase II teams (P=0.08). There was no significant difference between phases in time required for the surgeon to be at the bedside (average 132.2 seconds, P=0.64)., Conclusions: Targeted education can lead to improved team performance. This study shows that high-fidelity simulation and didactic sessions can both be used to effectively teach emergency undocking protocols., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form, except for author Bryce Bludevich, who is deceased (available at https://jtd.amegroups.com/article/view/10.21037/jtd-24-291/coif). K.U. reports grant funding from the Intuitive Foundation to his institution. The other authors have no conflicts of interest to declare., (2024 Journal of Thoracic Disease. All rights reserved.)

Background: Anastomotic leak is a serious complication after esophagectomy that has been associated with worse outcomes. However, identifying patients at increased risk for anastomotic leak remains challenging., Methods: Patients were included from the 2016 to 2021 National Surgical Quality Improvement Project database who underwent elective esophagectomy with gastric reconstruction for cancer. A multivariable logistic regression model was used to identify risk factors associated with anastomotic leak., Results: A total of 4,331 patients were included in the study, of whom 647 patients experienced anastomotic leak (14.9%). Multivariable logistic regression revealed higher odds of anastomotic leak with smoking (adjusted odds ratio 1.24, confidence interval 1.02-1.51, P = .031), modified frailty index-5 score of 1 (adjusted odds ratio 1.44, confidence interval 1.19-1.75, P = .002) or 2 (adjusted odds ratio 1.52, confidence interval 1.19-1.94, P = .000), and a McKeown esophagectomy (adjusted odds ratio 1.44, confidence interval 1.16-1.80, P = .001). Each 1,000/μL increase in white blood cell count was associated with a 7% increase in odds of anastomotic leak (adjusted odds ratio 1.07, confidence interval 1.03-1.10, P = .0005). Higher platelet counts were slightly protective, and each 10,000/ μL increase in platelet count was associated with 2% reduced odds of anastomotic leak (adjusted odds ratio 0.98, confidence interval 0.97-0.99, P = .001)., Conclusion: In this study, smoking status, frailty index, white blood cell count, McKeown esophagectomy, and platelet counts were all associated with the occurrence of anastomotic leak. These results can help to inform surgeons and patients of the true risk of developing anastomotic leak and potentially improve outcomes by providing evidence to improve preoperative characteristics, such as frailty., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Digital chest drainage systems (DCDS) provide reliable pleural drainage while quantifying fluid output and air leak. However, the benefits of DCDS in the contemporary era of minimally invasive thoracic surgery and enhanced recovery after surgery (ERAS) protocols have not been fully investigated. Additionally, hospital and resident staff experiences after implementation of a DCDS have not been fully explored. The objective of this study was to evaluate the clinical outcomes and hospital staff experience after adoption of a DCDS for minimally invasive lung resections., Methods: A single-center retrospective review of patients who underwent minimally invasive lung resection (lobectomy, segmentectomy, and wedge resection) and received a DCDS from 11/1/2021 to 11/1/2022. DCDS patients were compared to sequential historical controls (3/1/2019-6/30/2021) who received a analog chest drainage system. For the analog system, chest tubes were removed when no bubbles were observed in the water seal compartment with Valsalva, cough, and in variable positions. With a DCDS, chest tubes were removed when the air leak was less than 30 cc/min for 8 hours, with no spikes. All patients followed an institutional ERAS protocol. Primary outcomes were length of stay (LOS) and chest tube duration. Hospital staff and residents were surveyed regarding their experience., Results: One hundred and twenty-four patients received DCDS, and 248 received an analog chest drainage system. There was a reduction in mean LOS (3.6 vs . 4.4 days, P=0.01) and chest tube duration (2.7 vs . 3.6 days, P=0.03) in the DCDS group. Hospital staff (n=77, 46% response rate) reported the DCDS easier to use (60%, P<0.001) and easier to care for patients with (65%, P<0.001) compared to the analog system. Surgical residents (n=28, 56% response rate) reported increased confidence in interpretation of air leak (75%, P<0.001) and decision-making surrounding chest tube removal (79%, P<0.001)., Conclusions: Using a DCDS can reduce LOS and chest tube duration in the contemporary setting of minimally invasive lung resections and ERAS protocols. Increased confidence of resident decision-making for chest tube removal may contribute to improved outcomes., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://jtd.amegroups.com/article/view/10.21037/jtd-23-1747/coif). M.W.M. received lecture fees from Intuitive Surgical, unrelated to the content of this manuscript. The other authors have no conflicts of interest to declare., (2024 Journal of Thoracic Disease. All rights reserved.)

Background: Enhanced recovery after surgery (ERAS) protocols in thoracic surgery have been demonstrated to impact length of stay (LOS), complication rates, and postoperative opioid use. However, ERAS protocols for minimally invasive lung resections have not been well described. Given most lung resections are now performed minimally invasively, there is a gap in the literature regarding the efficacy of ERAS protocols in this setting. In this study, we analyzed patient outcomes following implementation of an ERAS protocol for minimally invasive lung resections., Methods: Outcome data was retrospectively collected for 442 patients undergoing minimally invasive lung resections between January 1 st , 2015 and October 26 th , 2021. Patients were divided into either a pre-ERAS (n=193) or ERAS (n=249) group. Primary outcomes included LOS, postoperative complications, intensive care unit (ICU) admission status, 30-day hospital readmissions, and 30-day mortality. Secondary outcomes included common postoperative complications required for the Society for Thoracic Surgeons (STS) database., Results: We observed an overall decrease in median LOS (4.0 vs. 3.0 days, P=0.030) and ICU admission status (15% vs. 7.6%, P=0.020) after implementation of our ERAS protocol. The difference in LOS was significantly lower for anatomic lung resections, but not non-anatomic resections. There was no difference in 30-day readmissions and a 0% mortality rate in both groups. Overall, there was a low complication rate that was similar between groups., Conclusions: The implementation of an ERAS protocol led to decreased LOS and decreased ICU admission in patients undergoing minimally invasive lung resection. Process standardization optimizes performance by providers by decreasing decision fatigue and improving decision making, which may contribute to the improved outcomes observed in this study., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://jtd.amegroups.com/article/view/10.21037/jtd-23-1500/coif). M.W.M. received lecture fees from Intuitive Surgical, unrelated to the content of this manuscript. The other authors have no conflicts of interest to declare., (2024 Journal of Thoracic Disease. All rights reserved.)

Acute esophageal necrosis may be a potential complication of Coronavirus Disease 2019 (COVID-19). COVID-19 has been associated with a variety of sequelae, including acute respiratory distress syndrome, myocarditis, and thromboembolic events. Here, we present a case of a 43-year-old male who was admitted for acute necrotizing pancreatitis and found to have COVID-19 pneumonia. He subsequently developed acute esophageal necrosis requiring a total esophagectomy. Currently, there are at least five other reported cases of esophageal necrosis with concomitant COVID-19 infection. This case is the first requiring esophagectomy. Future studies may establish esophageal necrosis as a known complication of COVID-19., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

There has been a recent shift in medical student anatomy education with greater incorporation of virtual resources. Multiple approaches to virtual anatomy resources have been described, but few involve video or images from surgical procedures. In this pilot study, a series of surgical case videos was created using robotic surgery video footage for a first-year medical student anatomy course. Five operations were included that covered thoracic, abdominal, and pelvic anatomy. Students were surveyed at the end of the course regarding their experience with the videos and their perceptions towards a surgical career. Overall, participants agreed that the videos were an effective learning tool, were useful regardless of career interest, and that in the future it would be useful to incorporate additional surgical case videos. Respondents highlighted the importance of audio narration with future videos and provided suggestions for future operations that they would like to see included. In summary, this pilot study describes the creation and implementation of a surgical video anatomy curriculum and student survey results suggest this may be an effective approach to video-based anatomy education for further curricular development., (© 2023 American Association for Anatomy.)

A subset of patients with marginal ulcers after Roux-en-Y gastric bypass (RNYGB) is refractory to medical management. Here we report a retrospective review of a single institution cohort (N = 10) of video- or robotic-assisted thoracoscopic (VATS or RATS) truncal vagotomies performed between 2013 and 2018. All patients had recurrent marginal ulcers following RNYGB complicated by bleeding or perforation, refractory to medical management for a median of 3.5 months prior to undergoing truncal vagotomy. With a median of 23 months' follow-up, only three patients had continued symptoms (70% symptom resolution) post-operatively. Only one patient who had repeat endoscopy after the procedure had documented endoscopic evidence of recurrent marginal ulcer (83% endoscopic resolution). VATS or RATS truncal vagotomy is a safe and effective method to treat complicated marginal ulceration after RNYGB. After an average duration of unsuccessful medical treatment lasting three months, vagotomy led to successful resolution in 70-83% of patients.

Introduction: Rapid onsite evaluation (ROSE) generally uses smears made at the site of the procedure ("smear-based ROSE"). It requires considerable time, generally 2 individuals, technical expertise, and it can be difficult to estimate material available for ancillary studies. We developed an alternative ROSE using liquid-based cytology ThinPrep with hematoxylin and eosin (H&E) stain ("liquid-based ROSE") and assessed its advantages., Materials and Methods: Clinicians rinse the sample(s) into CytoRich Red and send to Pathology. A defined proportion of the needle rinse is removed for a ThinPrep stained with a rapid H&E. Adequacy and diagnosis were compared to final outcome. Total time was recorded., Results: Among 52 liquid-based ROSE readings, 28 (53.8%) were interpreted as "adequate" with final as adequate; 17 (32.7%) were interpreted as "inadequate" with final as inadequate; 7 (13.5%) were interpreted as "inadequate" with final as adequate. Of 23 readings provided with onsite diagnosis, 15 (65.2%) were interpreted as definitive positive or negative diagnoses; 6 (26%) were interpreted as nondiagnostic; and 2 (8.7%) were interpreted as atypical. All definitive diagnoses were concordant with final diagnoses. The time for liquid ROSE performance ranges from 6 to 22 minutes (mean: 13 minutes) and required only 1 individual., Conclusions: Liquid-based ROSE allows accurate adequacy determination and diagnosis, takes about 15 minutes of cytologist time, and can be performed by just 1 person. The technique produces well-preserved and stained slides, it may allow a better estimation of the total amount of material in the specimen vial and may provide a better platform for telecytology., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

Chordomas are rare, slowly growing, aggressive primary bone tumors that originate from notochord remnants and occur almost exclusively in the axial skeleton. Here, we describe a patient with an enlarging right-sided neck mass that was later diagnosed as a sternoclavicular joint chondroid chordoma. En bloc surgical resection was accomplished with negative margins. The patient continues to do well 15 months after resection without radiotherapy. This case highlights the importance of considering a wide differential in managing sternoclavicular joint tumors., (© 2022 The Authors.)

In this case report, we present a 25-year-old woman who was diagnosed with anti-N-methyl-D-aspartate (NMDA) receptor encephalitis and subsequently was found to have thymic hyperplasia. She underwent robotic bilateral access thymectomy for treatment of her anti-NMDA receptor encephalitis and has remained asymptomatic after her operation without any medication. This is only the second reported case of thymectomy for treatment of this condition. This case may further suggest thymic tissue is involved in the development of anti-NMDA receptor encephalitis and that thymectomy is an appropriate treatment for a subset of patients with this disease., (© The Author(s) 2022. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

Introduction: With the advancement of robotic surgery, some thoracic surgeons have been slow to adopt to this new operative approach, in part because they are un-scrubbed and away from the patient while operating. Aiming to allay surgeon concerns of intra-operative emergencies, an insitu simulation-based clinical system's test (SbCST) can be completed to test the current clinical system, and to practice low-frequency, high-stakes clinical scenarios with the entire operating room (OR) team., Methods: Six different OR teams completed an insitu SbCST of an intra-operative pulmonary artery injury during a robot-assisted thoracic surgery at a single tertiary care center. The OR team consisted of an attending thoracic surgeon, surgery resident, anesthesia attending, anesthesia resident, circulating nurse, and a scrub technician. This test was conducted with an entire OR team along with study observers and simulation center staff. Outcomes included the identified latent safety threats (LSTs) and possible solutions for each LST, culminating in a complete failure mode and effects analysis (FMEA). A Risk Priority Number (RPN) was determined for each LST identified. Pre- and post-simulation surveys using Likert scales were also collected., Results: The six FMEAs identified 28 potential LSTs in four categories. Of these 28 LSTs, nine were considered high priority based on their Risk Priority Number (RPN) with seven of the nine being repeated multiple times. Pre- and post-simulation survey responses were similar, with the majority of participants (94%) agreeing that high fidelity simulation of intra-operative emergencies is helpful and provides an opportunity to train for high-stakes, low-frequency events. After completing the SbCST, more participants felt confident that they knew their role during an intra-operative emergency than their pre-simulation survey responses. All participants agreed that simulation is an important part of continuing education and is helpful for learning skills that are infrequently used. Following the SbCST, more participants agreed that they knew how to safely undock the da Vinci robot during an emergency., Conclusions: SbCSTs provide an opportunity to test the current clinical system with a low-frequency, high-stakes event and allow medical personnels to practice their skills and teamwork. By completing multiple SbCSTs, we were able to identify multiple LSTs within different OR teams, allowing for a broader review of the current clinical systems in place. The use of these SbCSTs in conjunction with debriefing sessions and FMEA completion allows for the most significant potential improvement of the current system. This study shows that SbCST with FMEA completion can be used to test current systems and create better systems for patient safety., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Competing Interests: Conflict of Interest None.

Background: Left ventricular (LV) remodeling following a myocardial infarction (MI) is associated with new-onset atrial fibrillation (AF). LV remodeling post-MI is characterized by regional changes in matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs), causing extracellular matrix (ECM) remodeling., Objective: The purpose of this study was to test the hypothesis that a shift in regional atrial MMP activity, MMP/TIMP expression, and ECM remodeling occurs post-MI, which cause increased vulnerability to AF., Methods: MI was induced in pigs (weight 25 kg; coronary ligation; n = 9). At approximately 14 days post-MI, an atrial electrical stimulation protocol was performed, after which an MMP radiotracer was infused, MMP/TIMP mRNA profiling performed, and ECM collagen assessed by histochemistry. An additional 7 non-MI pigs served as controls., Results: AF could be induced in 89% (8/9) of the post-MI pigs but none of the controls. MMP activity (MMP radiotracer uptake) increased by approximately 2-fold in most atrial regions post-MI, whereas fibrillar collagen content was unchanged or actually reduced in right atrial regions and increased in left atrial regions. MMP/TIMP profiles revealed a heterogeneous pattern from the left atrial appendage to right atrial regions., Conclusion: AF vulnerability early post-MI was associated with a heterogeneous pattern of atrial ECM remodeling, detectable by noninvasive molecular imaging. Detection of early atrial MMP activation post-MI may help define the myocardial substrate underlying AF., (Copyright © 2022 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Paraconduit hiatal hernia (PCHH) is a known complication of esophagectomy with significant morbidity. PCHH may be more common with the transition to a minimally invasive approach and improved survival. We studied the PCHH occurrence following minimally invasive esophagectomy to determine the incidence, treatment, and associated risk factors., Methods: We retrospectively reviewed records of patients who underwent esophagectomy at an academic tertiary care center between 2013-2020. We divided the cohort into those who did and did not develop PCHH, identifying differences in demographics, perioperative characteristics and outcomes. We present video of our laparoscopic repair with mesh., Results: Of 49 patients who underwent esophagectomy, seven (14%) developed PCHH at a median of 186 d (60-350 d) postoperatively. They were younger (57 versus 64 y, P< 0.01), and in cases of resection for cancer, more likely to develop tumor recurrence (71% versus 23%, P= 0.02). There was a significant difference in 2-y cancer free survival of patients with a PCHH (PCHH 19% versus no hernia 73%, P< 0.01), but no significant difference in 5-y overall survival (PCHH 36% versus no hernia 68%, P= 0.18). Five of seven PCHH were symptomatic and addressed surgically. Four PCHH repairs recurred at a median of 409 d., Conclusions: PCHH is associated with younger age and tumor recurrence, but not mortality. Safe repair of PCHH can be performed laparoscopically with or without mesh. Further studies, including systematic video review, are needed to address modifiable risk factors and identify optimal techniques for durable repair of post-esophagectomy PCHH., (Copyright © 2021. Published by Elsevier Inc.)

The benefits of percutaneous dilational tracheostomy (PDT) placement have been well documented in patients requiring prolonged mechanical ventilation. However, the data regarding the benefit of PDT in coronavirus-2019 (COVID-19) patients are scarce. The objective of this study is to evaluate the outcomes of a cohort of 37 patients who underwent tracheostomy as part of their COVID-19 care. Retrospective data from a series for 37 patients undergoing tracheostomy was collected using chart review. Primary outcomes included 30 and 60 day mortality, weaning rate, and decannulation rate. Secondary outcomes collected included admission demographics, comorbidities, and procedural information. Thirty-seven (37) patients requiring prolonged mechanical ventilation due to COVID-19. Of these 37 patients, 35 were alive 60 days post-PDT placement, 33 have been weaned from mechanical ventilation and 18 have been decannulated. The low mortality and high decannulation rates in this cohort in is a promising development in the care of critically ill COVID-19 patients. Of note, all participating physicians underwent routine polymerase chain reaction (PCR) testing for infection with the severe acute respiratory syndrome coronavirus-2 virus and no physician contracted COVID-19 as a result of their involvement. Overall, this case series describes the modified PDT technique used by our team and discusses the feasibility and potential benefit to PDT placement in COVID-19 patients requiring long-term mechanical ventilation.

Background: Burnout has been linked to poor job satisfaction and increased medical errors, and is prevalent among health care professionals. We sought to characterize burnout and distress among US cardiothoracic surgery (CTS) trainees., Methods: A 19-question survey was sent to CTS trainees in collaboration with the Thoracic Surgery Residents Association. We queried sociodemographic variables, balance/quality of life, and indicators of depression and regret. We included questions along the emotional exhaustion, depersonalization, and personal accomplishment subscales of the Maslach Burnout Inventory., Results: The survey was sent to 531 CTS trainees across 76 institutions and there were 108 responses (20.3%). More than 50% of respondents expressed dissatisfaction with balance in their professional life and more than 40% screened positively for signs of depression. More than 25% of respondents (n = 28) would not complete CTS training again, given a choice. More than half met criteria for burnout on emotional exhaustion and depersonalization subscales. The CTS residents with children were more likely to express regret toward pursuing CTS training. A greater proportion of women than men reported poor levels of balance/quality of life during training as measured by missed health appointments, negative impact on relationships, and self-perception. Similarly, those in the final 3 years of training were more likely to report poor levels of balance/quality of life., Conclusions: High rates of burnout, regret, and depression are present among US CTS trainees. Efforts to promote trainee well-being and implement interventions that support those at high risk for burnout are warranted, to benefit trainees as well as the patients they serve., (Copyright © 2021 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Objective: Minimally invasive (video-assisted thoracoscopic surgery) mediastinal parathyroidectomy has been described as a technique for surgical management of primary hyperparathyroidism due to ectopic parathyroid adenoma. Herein, we present the largest cohort of patients ( n  = 8) treated with robot-assisted mediastinal parathyroidectomy and describe our technique for this procedure, pre- and intraoperative variables, and postoperative outcomes. Materials and Methods: A single surgeon, single institution case series of eight consecutive robot-assisted mediastinal parathyroidectomies performed from April 2013 to March 2018. Preoperative workup, intraoperative variables, and postoperative outcomes were evaluated. Results: Of the eight patients, seven were women. Average age was 54 years (range: 28-69) and average body mass index 33.6 (range: 24.8-42.9). Seven patients had a preoperative diagnosis of primary hyperparathyroidism with preoperative parathyroid hormone (PTH) and calcium levels (PTH: 137 (70-192); Ca 2+ : 10.9 (10.2-12), and one patient had preoperative diagnosis of thymoma. Preoperative imaging studies included computed tomography (CT)-sestamibi ( n  = 3), CT neck ( n  = 4), CT chest ( n  = 6), and neck ultrasound ( n  = 6). Intraoperative PTH measurements found >50% reduction in all cases. Average length of surgery was 108.6 minutes (range: 76-186); average blood loss 26 cc. All specimens were parathyroid adenomas, with an average size of 16 mm (range: 7-35 mm). Seven of eight patients were discharged on postoperative day 1. No complications or recurrences occurred at a median follow-up of 18.5 days (range: 15-1,066 days). Conclusions: Robot-assisted thoracoscopic parathyroidectomy is a safe and effective technique, with immediate improvement in PTH levels. Thorough clinical, biochemical, and radiologic preoperative workup assists in operative planning and may improve diagnostic accuracy of anterior mediastinal masses.

Electrospinning is commonly used to generate polymeric scaffolds for tissue engineering. Using this approach, we developed a small-diameter tissue engineered vascular graft (TEVG) composed of poly-ε-caprolactone-co-l-lactic acid (PCLA) fibers and longitudinally assessed its performance within both the venous and arterial circulations of immunodeficient (SCID/bg) mice. Based on in vitro analysis demonstrating complete loss of graft strength by 12 weeks, we evaluated neovessel formation in vivo over 6-, 12- and 24-week periods. Mid-term observations indicated physiologic graft function, characterized by 100% patency and luminal matching with adjoining native vessel in both the venous and arterial circulations. An active and robust remodeling process was characterized by a confluent endothelial cell monolayer, macrophage infiltrate, and extracellular matrix deposition and remodeling. Long-term follow-up of venous TEVGs at 24 weeks revealed viable neovessel formation beyond graft degradation when implanted in this high flow, low-pressure environment. Arterial TEVGs experienced catastrophic graft failure due to aneurysmal dilatation and rupture after 14 weeks. Scaffold parameters such as porosity, fiber diameter, and degradation rate informed a previously described computational model of vascular growth and remodeling, and simulations predicted the gross differential performance of the venous and arterial TEVGs over the 24-week time course. Taken together, these results highlight the requirement for in vivo implantation studies to extend past the critical time period of polymer degradation, the importance of differential neotissue deposition relative to the mechanical (pressure) environment, and further support the utility of predictive modeling in the design, use, and evaluation of TEVGs in vivo. STATEMENT OF SIGNIFICANCE: Herein, we apply a biodegradable electrospun vascular graft to the arterial and venous circulations of the mouse and follow recipients beyond the point of polymer degradation. While venous implants formed viable neovessels, arterial grafts experienced catastrophic rupture due to aneurysmal dilation. We then inform a previously developed computational model of tissue engineered vascular graft growth and remodeling with parameters specific to the electrospun scaffolds utilized in this study. Remarkably, model simulations predict the differential performance of the venous and arterial constructs over 24 weeks. We conclude that computational simulations should inform the rational selection of scaffold parameters to fabricate tissue engineered vascular grafts that must be followed in vivo over time courses extending beyond polymer degradation., (Copyright © 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

Coronary microvascular disease (MVD) remains a major clinical problem due to limited mechanistic understanding and a challenging diagnosis. In the present study we evaluated the utility of targeted imaging of active factor XIII (FXIII) for detection of coronary MVD associated with thrombus. We hypothesized that a high specificity and sensitivity FXIII targeted radiolabeled probe can serve as a biomarker for cross-linked thrombi in the microvasculature, and thus an indicator for underlying coronary MVD. To evaluate this approach, a coronary MVD model was established for local induction of singlet oxygen and reactive oxygen species (ROS) via a photochemical reaction (PCR). Methods: PCR was used to induce endothelial injury and microthrombi via focal over-production of ROS only in the coronary microvasculature. Oxidative stress was initially evaluated in primary coronary endothelial cells to optimize parameters of PCR, which were then translated to in vivo experiments. To develop the coronary MVD model, 64 mice were assigned to one of four groups after thoracotomy: 1) sham control; 2) rose bengal; 3) green light; or 4) their combination. Following interventions, the mice underwent transmission electron microscopy, fluorescent myocardial perfusion, coronary angiography, and immunohistochemical staining. Echocardiography (n = 12) and gene expression (n = 10) studies were also performed after MVD induction to monitor serial changes in cardiac function and explore possible mechanisms. To diagnose early onset MVD, FXIII radioactivity was assessed in 104 mice using ex vivo gamma well counting (GWC) and in 14 mice using in vivo serial single photon emission computed tomography / computed tomography (SPECT/CT) imaging of a FXIII targeted technetium-labeled probe ( 99m Tc-NC100668). Results: In vitro experiments demonstrated that photosensitizer concentration and light illumination time were critical parameters for PCR. In vivo experiments demonstrated manifestations of clinical MVD, including endothelial damage, a "no flow zone," arteriole rarefaction with patent epicardial coronary arteries, infiltration of inflammatory cells in the PCR-treated region, and preserved cardiac function. Gene expression also demonstrated a pro-thrombotic and impaired fibrinolytic status. In the early stages of MVD, enhanced FXIII activity was confirmed within the MVD region using GWC and in vivo SPECT/CT imaging. Conclusion: Our results demonstrate that molecular imaging of FXIII activity may allow for early detection of coronary MVD associated with thrombus, in a novel pre-clinical model., Competing Interests: Competing Interests: The authors have declared that no competing interest exists.

Objectives: Tissue-engineered vascular grafts (TEVGs) have demonstrated potential for treating congenital heart disease (CHD); however, quantitative imaging for tracking functional and structural remodeling of TEVGs has not been applied. Therefore, we evaluated the potential of magnetic resonance (MR) imaging for assessing TEVG wall shear stress (WSS) and wall thickness in a large animal model., Methods: Cell-seeded (n = 3) or unseeded (n = 3) TEVGs were implanted as inferior vena cava interposition grafts in juvenile lambs. Six months following implantation, two-dimensional phase-contrast MR imaging was performed at 3 slice locations (proximal, middle, and distal) to assess normalized WSS (i.e., WSS-to-cross sectional area). T2-weighted MR imaging was performed to assess TEVG wall thickness. Histology was qualitatively assessed, whereas immunohistochemistry was semiquantitatively assessed for smooth muscle cells (αSMA), macrophage lineage cells (CD11b), and matrix metalloproteinase activity (MMP-2 and MMP-9). Picrosirius Red staining was performed to quantify collagen content., Results: TEVG wall thickness was significantly higher for proximal, middle, and distal slices in unseeded versus cell-seeded grafts. Significantly higher WSS values existed for proximal versus distal slice locations for cell-seeded TEVGs, whereas no differences in WSS existed between slices for unseeded TEVGs. Additionally, no differences in WSS existed between cell-seeded and unseeded groups. Both groups demonstrated elastin formation, without vascular calcification. Unseeded TEVGs possessed greater content of smooth muscle cells when compared with cell-seeded TEVGs. No differences in macrophage, MMP activity, or collagen content existed between groups., Conclusion: MR imaging allows for in vivo assessment of functional and anatomical characteristics of TEVGs and may provide a nonionizing approach that is clinically translatable to children undergoing treatment for CHD.

Objectives: Among surgical educators, duty-hour restrictions led to concern regarding the adequacy of operative experience during residency, especially for junior residents. The American Board of Surgery recently instituted guidelines mandating "a minimum of 250 operations by the end of the PGY-2 year". A series of programmatic and institutional changes were implemented at our institution to augment the junior resident operative experience and to exceed compliance with this mandate., Methods: Operative data from Accreditation Council for Graduate Medical Education case logs for categorical and nondesignated preliminary interns from our large academic surgical residency were identified for 5 consecutive academic years, 2011 until 2016. American Board of Surgery In-Training Examination (ABSITE) scores were collected anonymously. The program systematically instituted the following changes: night float minimization, identification of new surgical opportunities, augmenting use of midlevel care providers, identification of rotations with suboptimal operative experiences, maximizing rotations with involvement of junior residents in the operating room, and systematic review of junior case logs., Results: After implementation, average total cases for residents completing postgraduate year (PGY)-2 increased from 176 to 330 (p < 0.001). Specifically, there was an 18% increase for interns (p = 0.059) and a 118% increase for PGY-2 residents (p < 0.001). There were statistically significant increases in skin and soft tissue cases, vascular cases, endoscopy, and complex laparoscopic cases. Average case volumes for senior residents did not change. Night float time was significantly decreased (5.7 vs 3.4 wk; p = 0.04). ABSITE scores were not significantly changed during this time., Conclusions: Before implementation of these interventions, our program would have had 0% compliance with the 250 junior resident case rule. Within 12 months of implementation, total case volumes for residents completing PGY-2 increased by 88%-exceeding minimum standards. Overall, 100% programmatic compliance was achieved. Our program's experience exemplifies how mandates from the American Board of Surgery can lead to programmatic changes that improve the experience of surgical house officers., (Copyright © 2017 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.)

Aim: Surgical management of pediatric extrahepatic portal vein obstruction requires meso-Rex bypass using autologous or synthetic grafts. Tissue-engineered vascular grafts (TEVGs) provide an alternative, but no validated animal models using portal TEVGs exist. Herein, we preclinically assess TEVGs as portal vein bypass grafts., Materials & Methods: TEVGs were implanted as portal vein interposition conduits in SCID-beige mice, monitored by ultrasound and micro-computed tomography, and histologically assessed postmortem at 12 months., Results: TEVGs remained patent for 12 months. Histologic analysis demonstrated formation of neovessels that resembled native portal veins, with similar content of smooth muscle cells, collagen type III and elastin., Conclusion: TEVGs are feasible portal vein conduits in a murine model. Further preclinical evaluation of TEVGs may facilitate pediatric clinical translation.

Background: Although there is increasing literature about burnout and attrition among surgeons, little is known about personal and professional well-being of surgical trainees., Study Design: General surgery residents from the 6 New England states participated in a cross-sectional, qualitative, self-reported survey to assess the domains of personal health maintenance, personal finance, work environment, and fatigue management as they relate to surgical training., Results: All surgical residency programs in the New England region were invited to participate. Of these 19 programs, 10 elected to participate in the study. Three hundred and sixty-three total trainees were contacted with requests to participate, and 166 completed responses to the survey, resulting in a response rate of 44.9%. Ninety percent of respondents identified their programs as "university or academic." Substantial cohorts reported that during training they lacked basic healthcare maintenance visits (54%) and had undesired weight gain (44%). Although most found their stipends adequate, three-quarters worried about their finances (75%) and reported substantial educational debt (45%). Most residents enjoyed coming to work; however, the vast majority reported that work-related stress is moderate to extreme (92%). Most also reported that work-related stress negatively affects their overall well-being (72%). The mean Epworth Sleepiness Scale score among respondents was 14, consistent with moderate excessive daytime sleepiness., Conclusions: Surgical trainee well-being is critical to optimal patient care, career development, and burnout reduction. Surgical residents attend to their own preventive health maintenance, finances, sleep, and stress reduction with variable success. Residency programs should make modest programmatic accommodations to allow trainees to tend to various aspects of their personal well-being., (Copyright © 2017. Published by Elsevier Inc.)

Competing Interests: Competing interests: None declared.

Objective: Autologous grafts are used to repair atherosclerotic cardiovascular diseases; however, many patients lack suitable donor graft tissue. Recently, tissue engineering techniques have emerged to make biologically active blood vessels. We applied this technique to produce arterial grafts using established biodegradable materials without cell seeding. The grafts were evaluated in vivo for vessel remodeling during 12 months., Methods: Poly(L-lactide-co-ε-caprolactone) scaffolds reinforced by poly(lactic acid) (PLA) fiber were prepared as arterial grafts. Twenty-eight cell-free grafts were implanted as infrarenal aortic interposition grafts in 8-week-old female SCID/Bg mice. Serial ultrasound and micro computed tomography angiography were used to monitor grafts after implantation. Five grafts were harvested for histologic assessments and reverse transcription-quantitative polymerase chain reaction analysis at time points ranging from 4 months to 1 year after implantation., Results: Micro computed tomography indicated that most implanted mice displayed aneurysmal changes (three of five mice at 4 months, four of five mice at 8 months, and two of five mice at 12 months). Histologic assessments demonstrated extensive tissue remodeling leading to the development of well-circumscribed neovessels with an endothelial inner lining, a neointima containing smooth muscle cells and elastin, and a collagen-rich extracellular matrix. There were a few observed calcified deposits, located around residual PLA fibers at 12 months after implantation. Macrophage infiltration into the scaffold, as evaluated by F4/80 immunohistochemical staining, remained after 12 months and was focused mostly around residual PLA fibers. Reverse transcription-quantitative polymerase chain reaction analysis revealed that gene expression of Itgam, a marker for macrophages, and of matrix metalloproteinase 9 was higher than in native aorta during the course of 12 months, indicating prolonged inflammation (Itgam at 8 months: 11.75 ± 0.99 vs native aorta, P < .01; matrix metalloproteinase 9 at 4 months: 4.35 ± 3.05 vs native aorta, P < .05)., Conclusions: In this study, we demonstrated well-organized neotissue of cell-free biodegradable arterial grafts. Although most grafts experienced aneurysmal change, such findings provide insight into the process of tissue-engineered vascular graft remodeling and should allow informed rational design of the next generation of arterial grafts., (Copyright © 2015 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Pleomorphic liposarcomas are rare entities with less than 40 cases diagnosed each year, of which a small proportion arise from the chest wall. Optimal management involves wide local resection with negative margins. We describe the case of a 69-year-old gentleman with a chronically growing chest wall mass. After computed tomography and positron-emission tomography, the mass was resected. Chest wall reconstruction was performed with mesh and a transverse rectus abdominis myocutaneous flap. The patient did well postoperatively, with no evidence of recurrence at 10 months., (© The Author(s) 2014.)

Our approach for fabricating tissue-engineered vascular grafts (TEVG), applied in the surgical management of congenital heart disease, is accomplished by seeding isolated bone marrow-derived mononuclear cells (BM-MNCs) onto biodegradable scaffolds. The current method used for isolation of BM-MNCs is density centrifugation in Ficoll. This is a time-consuming, labor-intensive, and operator-dependent method. We previously demonstrated that a simpler, faster, and operator-independent method for isolating BM-MNCs using a filter elution technique was feasible. In this study, we compare the use of each technique to determine if the BM-MNCs isolated by the filtration elution method are biologically equivalent to BM-MNCs isolated using density centrifugation. Scaffolds were constructed from a nonwoven poly(glycolic acid) fiber mesh coated with 50:50 poly(l-lactide-co-ɛ-caprolactone) sealant. BM-MNCs were isolated from the bone marrow of syngeneic C57BL/6 mice by either density centrifugation with Ficoll or filtration (Ficoll vs. Filter), then statically seeded onto scaffolds, and incubated overnight. The TEVG were implanted in 10-week-old C57BL/6 mice (n=23 for each group) as inferior vena cava interposition grafts and explanted at 14 days for analysis. At 14 days after implantation, there were no significant differences in graft patency between groups (Ficoll: 87% vs. Filter: 78%, p=0.45). Morphometric analysis by hematoxylin and eosin staining showed no difference of graft luminal diameter or neointimal thickness between groups (luminal diameter, Ficoll: 620.3±82.9 μm vs. Filter: 633.3±131.0 μm, p=0.72; neointimal thickness, Ficoll: 37.9±7.8 μm vs. Filter: 37.9±11.2 μm, p=0.99). Histologic examination demonstrated similar degrees of cellular infiltration and extracellular matrix deposition, and endothelial cell coverage on the luminal surface, in either group. Macrophage infiltration showed no difference in the number of F4/80-positive cells or macrophage phenotypes between the two experimental groups (Ficoll: 2041±1048 cells/mm(2) vs. Filter: 1887±907.7 cells/mm(2), p=0.18). We confirmed the biological equivalence of BM-MNCs, isolated using either density centrifugation or filtration, for making TEVG.

The surgical repair of heart and vascular disease often requires implanting synthetic grafts. While synthetic grafts have been successfully used for medium-to-large sized arteries, applications for small diameter arteries (<6 mm) is limited due to high rates of occlusion by thrombosis. Our objective was to develop a tissue engineered vascular graft (TEVG) for small diameter arteries. TEVGs composed of polylactic acid nanofibers with inner luminal diameter between 0.5 and 0.6 mm were surgically implanted as infra-renal aortic interposition conduits in 25 female C17SCID/bg mice. Twelve mice were given sham operations. Survival of mice with TEVG grafts was 91.6% at 12 months post-implantation (sham group: 83.3%). No instances of graft stenosis or aneurysmal dilatation were observed over 12 months post-implantation, assessed by Doppler ultrasound and microCT. Histologic analysis of explanted TEVG grafts showed presence of CD31-positive endothelial monolayer and F4/80-positive macrophages after 4, 8, and 12 months in vivo. Cells positive for α-smooth muscle actin were observed within TEVG, demonstrating presence of smooth muscle cells (SMCs). Neo-extracellular matrix consisting mostly of collagen types I and III were observed at 12 months post-implantation. PCR analysis supports histological observations. TEVG group showed significant increases in expressions of SMC marker, collagen-I and III, matrix metalloproteinases-2 and 9, and itgam (a macrophage marker), when compared to sham group. Overall, patency rates were excellent at 12 months after implantation, as structural integrity of these TEVG. Tissue analysis also demonstrated vessel remodeling by autologous cell.

We developed a prototype for a closed apparatus for assembling tissue-engineered vascular grafts (TEVGs) with the goal of creating a simple operator-independent method for making TEVGs to optimize safety and enable widespread application of this technology. The TEVG is made by seeding autologous bone marrow-derived mononuclear cells onto a biodegradable tubular scaffold and is the first man-made vascular graft to be successfully used in humans. A critical barrier, which has prevented the widespread clinical adoption of the TEVG, is that cell isolation, scaffold seeding, and incubation are performed using an open method. To reduce the risk of contamination, the TEVG is assembled in a clean room. Clean rooms are expensive to build, complex to operate, and are not available in most hospitals. In this investigation, we used an ovine model to compare the safety and efficacy of TEVGs created using either a standard density centrifugation-based open method or the new filter-based closed system. We demonstrated no graft-related complications and maintenance of growth capacity in TEVGs created using the closed apparatus. In addition, the use of the closed system reduced the amount of time needed to assemble the TEVG by ∼ 50%. Adaptation of similar methodologies may facilitate the safe translation and the widespread use of other tissue engineering technologies.

There is great clinical demand for synthetic vascular grafts with improved long-term efficacy. The ideal vascular conduit is easily implanted, nonthrombogenic, biocompatible, resists aneurysmal dilatation, and ultimately degrades or is assimilated as the patient remodels the graft into tissue resembling native vessel. The field of vascular tissue engineering offers an opportunity to design the ideal synthetic graft, and researchers have evaluated a variety of methods and materials for use in graft construction. Electrospinning is one method that has received considerable attention within tissue engineering for constructing so-called tissue scaffolds. Tissue scaffolds are temporary, porous structures which are commonly composed of bioresorbable polymers that promote native tissue ingrowth and have degradation kinetics compatible with a patient's rate of extracellular matrix production in order to successfully transit from synthetic conduits into neovessels. In this review, we summarize the history of tissue-engineered vascular grafts (TEVG), focusing on scaffolds generated by the electrospinning process, and discuss in vivo applications. We review the materials commonly employed in this approach and the preliminary results after implantation in animal models in order to gauge clinical viability of the electrospinning process for TEVG construction. Scientists have studied electrospinning technology for decades, but only recently has it been orthotopically evaluated in animal models such as TEVG. Advantages of electrospun TEVG include ease of construction, favorable cellular interactions, control of scaffold features such as fiber diameter and pore size, and the ability to choose from a variety of polymers possessing a range of mechanical and chemical properties and degradation kinetics. Given its advantages, electrospinning technology merits investigation for use in TEVG, but an emphasis on long-term in vivo evaluation is required before its role in clinical vascular tissue engineering can be realized.

Objective: Tissue engineering techniques have emerged that allow bioresorbable grafts to be implanted that restore function and transform into biologically active arteries. However, these implants are susceptible to calcification during the remodeling process. The objective of this study was to evaluate the role of pore size of bioabsorbable grafts in the development of calcification., Methods: Two types of grafts were prepared: a large-pore graft constructed of poly(L-lactic acid) (PLA) fibers coated with poly(L-lactide-co-ε-caprolactone) (PLCL) (PLA-PLCL), and a small-pore graft made of electrospun PLA nanofibers (PLA-nano). Twenty-eight PLA-PLCL grafts and twenty-five PLA-nano grafts were implanted as infra-renal aortic interposition conduits in 8-week-old female SCID/Bg mice, and followed for 12 months after implantation., Results: Large-pore PLA-PLCL grafts induced a well-organized neointima after 12 months, and Alizarin Red S staining showed neointimal calcification only in the thin neointima of small-pore PLA-nano grafts. At 12 months, macrophage infiltration, evaluated by F4/80 staining, was observed in the thin neointima of the PLA-nano graft, and there were few vascular smooth muscle cells (VSMCs) in this layer. On the other hand, the neointima of the PLA-PLCL graft was composed of abundant VSMCs, and a lower density of macrophages (F4/80 positive cells, PLA-PLCL; 68.1 ± 41.4/mm(2) vs PLA-nano; 188.3 ± 41.9/mm(2), p = 0.007). The VSMCs of PLA-PLCL graft expressed transcription factors of both osteoblasts and osteoclasts., Conclusion: These findings demonstrate that in mouse arterial circulation, large-pore PLA-PLCL grafts created a well-organized neointima and prevented calcific deposition compared to small-pore, electrospun PLA-nano grafts., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Objectives: The clinical translation of tissue-engineered vascular grafts has been demonstrated in children. The remodeling of biodegradable, cell-seeded scaffolds to functional neovessels has been partially attributed to matrix metalloproteinases. Noninvasive assessment of matrix metalloproteinase activity can indicate graft remodeling and elucidate the progression of neovessel formation. Therefore, matrix metalloproteinase activity was evaluated in grafts implanted in lambs using in vivo and ex vivo hybrid imaging. Graft growth and remodeling was quantified using in vivo x-ray computed tomography angiography., Methods: Cell-seeded and unseeded scaffolds were implanted in 5 lambs as inferior vena cava interposition grafts. At 2 and 6 months after implantation, in vivo angiography was used to assess graft morphology. In vivo and ex vivo single photon emission tomography/computed tomography imaging was performed with a radiolabeled compound targeting matrix metalloproteinase activity at 6 months. The neotissue was examined at 6 months using qualitative histologic and immunohistochemical staining and quantitative biochemical analysis., Results: The seeded grafts demonstrated significant luminal and longitudinal growth from 2 to 6 months. In vivo imaging revealed subjectively greater matrix metalloproteinase activity in grafts versus native tissue. Ex vivo imaging confirmed a quantitative increase in matrix metalloproteinase activity and demonstrated greater activity in unseeded versus seeded grafts. The glycosaminoglycan content was increased in seeded grafts versus unseeded grafts, without significant differences in collagen content., Conclusions: Matrix metalloproteinase activity remained elevated in tissue-engineered grafts 6 months after implantation and could indicate remodeling. Optimization of in vivo imaging to noninvasively evaluate matrix metalloproteinase activity could assist in the serial assessment of vascular graft remodeling., (Copyright © 2014 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)

Background: The aim of this study was to assess the impact of digital versus traditional drainage devices on chest tube removal and patient satisfaction., Methods: A randomized trial of digital versus traditional devices after lobectomy/segmentectomy was conducted at 4 international centers (United Kingdom, Europe, Asia, United States). Patients were managed with overnight suction followed by gravity drainage. Chest tubes were removed when an air leak was not evident anymore and the drained fluid was less than 400 mL/d., Results: The groups (digital, 191 patients; traditional, 190 patients) were well matched for baseline and surgical characteristics. There were 325 lobectomies/bilobectomies and 56 segmentectomies, 308 of which were performed by video-assisted thoracic surgery (VATS). Patients randomized to digital systems had a significantly shorter air leak duration (1.0 versus 2.2 days; p=0.001), duration of chest tube placement (3.6 versus 4.7 days; p=0.0001), and postoperative length of stay (4.6 versus 5.6 days; p<0.0001). Subjective end points revealed a perceived improved ability to arise from bed (p=0.008), system convenience for patients and personnel (p=0.02), and the potential for being comfortable when discharged home with the device (p=0.06). A mean difference of 2.6 days from air leak cessation to tube removal was observed, which was similar in the 2 groups (p=0.7). Multivariable regression analysis showed that duration of chest tube placement after air leak cessation was directly associated with the amount of fluid drained during the first 48 hours (p=0.01) and the duration of air leak (p=0.008), independent of hospital location., Conclusions: Patients managed with digital drainage systems experienced a shorter duration of chest tube placement, shorter hospital stays, and higher satisfaction scores compared with those managed with traditional devices. (, Clinical Trial Registration Number: NCT01747889.)., (Copyright © 2014 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: Identifying patients on admission with perforated appendicitis who have phlegmon or abscess initially selected for but likely to fail nonoperative management may avoid delays in definitive treatment., Methods: Patients older than 15 years presenting to a university tertiary care hospital with perforated appendicitis and abscess or phlegmon and planned nonoperative management were reviewed. Comorbidities, clinical findings, laboratory markers, radiographic findings, and nonsurgical treatments associated with failure of nonoperative management were recorded., Results: Eighty-nine patients were identified, and 69 were managed successfully to discharge without operation. Length of stay was greater in the failure group (11 days vs. 5 days, p = 0.001), and intensive care unit care was more common (10% vs. 0%, p = 0.049). On univariate and multivariate analyses, smoking (odds ratio [OR], 13.20; 95% confidence interval [CI], 1.13-142; p = 0.039), tachycardia (OR, 4.93; 95% CI, 1.21-20.06; p = 0.026), and generalized abdominal tenderness (OR, 5.52; 95% CI, 1.40-21.73; p = 0.015) were associated with failure of nonoperative management. On computed tomographic scan, the failure group had higher rates of abscess (75% vs. 55%, p = 0.110), and their abscesses were more likely smaller than 50 mm (OR, 2.83; 95% CI, 1.01-7.92; p = 0.043)., Conclusion: Patients with perforated appendicitis and phlegmon or abscess who smoke or present with tachycardia, generalized abdominal tenderness, and abscesses smaller than 50 mm are more likely to fail nonoperative management and should be considered for early operation. These findings should be validated prospectively., Level of Evidence: Therapeutic study, level III.

Background: A standard quantitative imaging approach to evaluate peripheral arterial disease does not exist. Quantitative tools for evaluating arteriogenesis in vivo are not readily available, and the feasibility of monitoring serial regional changes in lower extremity perfusion has not been examined., Methods and Results: Serial changes in lower extremity arteriogenesis and muscle perfusion were evaluated after femoral artery occlusion in a porcine model using single photon emission tomography (SPECT)/CT imaging with postmortem validation of in vivo findings using gamma counting, postmortem imaging, and histological analysis. Hybrid 201Tl SPECT/CT imaging was performed in pigs (n=8) at baseline, immediately postocclusion, and at 1 and 4 weeks postocclusion. CT imaging was used to identify muscle regions of interest in the ischemic and nonischemic hindlimbs for quantification of regional changes in CT-defined arteriogenesis and quantification of 201Tl perfusion. Four weeks postocclusion, postmortem tissue 201Tl activity was measured by gamma counting, and immunohistochemistry was performed to assess capillary density. Relative 201Tl retention (ischemic/nonischemic) was reduced immediately postocclusion in distal and proximal muscles and remained lower in calf and gluteus muscles 4 weeks later. Analysis of CT angiography revealed collateralization at 4 weeks within proximal muscles (P<0.05). SPECT perfusion correlated with tissue gamma counting at 4 weeks (P=0.01). Increased capillary density was seen within the ischemic calf at 4 weeks (P=0.004)., Conclusions: 201Tl SPECT/CT imaging permits serial, regional quantification of arteriogenesis and resting tissue perfusion after limb ischemia. This approach may be effective for detection of disease and monitoring therapy in peripheral arterial disease.

Background: Although systemic hypertension is closely associated with aortic aneurysm (AA) formation, there are many patients with AA without hypertension. In these patients, an inflammation-mediated progression of aneurysmal disease is likely responsible for AA growth and eventual rupture. Unfortunately, there remains no reproducible and durable small animal model of aortic aneurysmal disease, the development of which would enable the investigation of the pathophysiology of this vexing condition. The first aim was to establish a useful wild-type mouse model of AA with low mortality. The second aim was to use this model to assess the protective effect of azelnidipine, a new calcium channel blocker, against the progression of the AA independent of its antihypertensive effect., Methods: Angiotensin II and β-aminopropionitrile (a lysyl oxidase inhibitor) were administrated subcutaneously in 7-week-old C57BL/6J mice using an osmotic minipump for 4 weeks to generate a wild-type mouse model of AA. Concurrently, azelnidipine (a calcium channel blocker) or a placebo was administrated orally for 4 weeks. Mice were humanely killed and assessed at the end of the 4 weeks of pharmacologic manipulation., Results: The combined infusion of angiotensin II and β-aminopropionitrile induced degenerative aneurysm of the thoracic and/or abdominal aorta (11/12; 92%). The majority of aneurysms were located in the distal aortic arch and suprarenal abdominal aorta. Although there was no difference in systolic blood pressure between the control and azelnidipine-treated groups, azelnidipine significantly reduced the incidence of AA (2/11; 18%). Azelnidipine treatment reduced the pathologic findings normally associated with aneurysm formation within the aortic wall. Azelnidipine also reduced the number of macrophage antigen-3 (MAC-3)-positive cells in the periaortic adipose tissue and reduced the gene expression levels of tumor necrosis factor-alpha and matrix metalloproteinase-2 and -9 within the aortic wall., Conclusions: This study demonstrates that combined treatment with angiotensin II and β-aminopropionitrile induces degenerative AAs in wild-type mice, and azelnidipine prevents aneurysm progression via its anti-inflammatory effect., (Copyright © 2013 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.)

Background: The optimal medical management to delay the progression of aortic aneurysms has not been fully clarified, and the only standard treatment at present is antihypertensive therapy. Previous studies have shown beneficial effects of selective mineralocorticoid receptor (MR) antagonists on cardiovascular remodeling. The aim of the present study was to investigate the effect of a selective MR antagonist on aortic aneurysm progression., Methods: Seven-week-old C57BL/6J male mice were administered with angiotensin II and β-aminopropionitrile for 4 weeks. The mice received either vehicle or eplerenone, a selective MR antagonist (100 mg/kg daily) every day by gavage, starting at 7 weeks of age. The production of inflammatory cytokines in cultures of high mobility group box-1-stimulated macrophages with or without a MR antagonist was also analyzed using an enzyme-linked immunosorbent assay., Results: Although no differences were found in the peak systolic blood pressure between the experimental groups, the mice in the eplerenone group showed a significant reduction in aneurysm development. On histologic analysis, coarse and stretched elastic fibers were markedly improved in the aortic wall in the eplerenone group. Real-time polymerase chain reaction of both aortic wall and perivascular adipose tissue demonstrated the expression of tumor necrosis factor-α, interleukin-6, and matrix metalloproteinase-2 was significantly decreased in eplerenone group, and that of monocyte chemoattractant protein-1 in the aortic wall was also significantly decreased. Macrophage infiltration in the aortic wall and perivascular adipose tissue in the eplerenone group was also significantly decreased. The production of tumor necrosis factor-α and interleukin-6 in macrophage culture, which was stimulated by high mobility group box-1 and CpG oligodeoxynucleotides, was also significantly decreased in the eplerenone group., Conclusions: Eprelenone suppressed aortic aneurysm progression through an anti-inflammatory effect. Thus, selective MR antagonists might be effective in preventing the progression of aortic aneurysms., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Aims: Excessive vascular remodelling leads to progression of a wide range of vasculopathies, and the immune response to intimal injuries is crucial in this process. This vascular remodelling occurs in the hypoxic microenvironment and is closely related to the immune system. Macrophages play a key role in immunological-cell-mediated arterial remodelling. In this study, we clarified the role of macrophage-derived hypoxia-inducible factor (HIF-1α) in vascular remodelling., Methods and Results: Wire-induced femoral arterial injury was inflicted in mice lacking the macrophage-specific HIF-1α gene and in their wild-type counterparts. The mutant mice showed both suppressed wire-induced neointimal thickening and decreased infiltration of inflammatory cells in the adventitia, compared with wild-type mice. Studies to clarify the mechanism of restrained vascular remodelling in the mutant mice revealed decreased production of pro-inflammatory cytokines by the activated macrophages and suppressed macrophage migration activity in the mutant mice. Gene expressions of the HIF-1α-deficient macrophages positively correlated with the phenotypic profile of M2 macrophages and negatively correlated with that of M1 macrophages., Conclusion: Our results show that HIF-1α in macrophages plays a crucial role in promoting vascular inflammation and remodelling. As decreasing HIF-1α activity in macrophages may prevent the progression of vascular remodelling, HIF-1α may be a possible therapeutic target in vascular diseases.

Bleeding disorders pose a significant perioperative risk. Surgeons and surgical consultants should have a working knowledge of the cell-based coagulation model. Careful screening for bleeding diatheses begins with a careful history and physical examination. It is paramount to ascertain what medications and nonprescribed supplements and herbal preparations a patient is taking, as these medications can have significant effects on perioperative bleeding tendencies. Finally, screening laboratory-based coagulation assays are available. These must be used judiciously with regard to a patient's history and the clinical circumstances surrounding the surgical stressor., (Copyright © 2013 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.)

Tissue engineering focuses on the construction of three-dimensional neotissues from their cellular components. Neotissue can be used to repair or replace tissues that are missing, damaged, or diseased. Despite its relative youth, the field has undergone significant growth. Vascular tissue engineering is at the forefront in the translation of this technology, as tissue engineered vascular grafts have already been successfully implanted in children with congenital heart disease. The purpose of this report is to review the advances in the understanding of tissue engineered vascular grafts as the technology moves to clinical translation.

Background: A recent study showed that computed tomographic (CT) scans contributed 93% of radiation exposure of 177 patients admitted to our Level I trauma center. Adaptive statistical iterative reconstruction (ASIR) is an algorithm that reduces the noise level in reconstructed images and therefore allows the use of less ionizing radiation during CT scans without significantly affecting image quality. ASIR was instituted on all CT scans performed on trauma patients in June 2009. Our objective was to determine if implementation of ASIR reduced radiation dose without compromising patient outcomes., Methods: We identified 300 patients activating the trauma system before and after the implementation of ASIR imaging. After applying inclusion criteria, 245 charts were reviewed. Baseline demographics, presenting characteristics, number of delayed diagnoses, and missed injuries were recorded. The postexamination volume CT dose index (CTDIvol) and dose-length product (DLP) reported by the scanner for CT scans of the chest, abdomen, and pelvis and CT scans of the brain and cervical spine were recorded. Subjective image quality was compared between the two groups., Results: For CT scans of the chest, abdomen, and pelvis, the mean CTDIvol (17.1 mGy vs. 14.2 mGy; p < 0.001) and DLP (1,165 mGy·cm vs. 1,004 mGy·cm; p < 0.001) was lower for studies performed with ASIR. For CT scans of the brain and cervical spine, the mean CTDIvol (61.7 mGy vs. 49.6 mGy; p < 0.001) and DLP (1,327 mGy·cm vs. 1,067 mGy·cm; p < 0.001) was lower for studies performed with ASIR. There was no subjective difference in image quality between ASIR and non-ASIR scans. All CT scans were deemed of good or excellent image quality. There were no delayed diagnoses or missed injuries related to CT scanning identified in either group., Conclusion: Implementation of ASIR imaging for CT scans performed on trauma patients led to a nearly 20% reduction in ionizing radiation without compromising outcomes or image quality., Level of Evidence: Therapeutic study, level IV.

In surgical repair for heart or vascular disease, it is often necessary to implant conduits or correct tissue defects. The most commonly used graft materials to date are (a) artificial grafts; (b) autologous tissues, such as pericardium and saphenous vein; (c) allografts; and (d) xenografts. However, none of these four options offer growth potential, and all are associated with varying levels of thrombogenicity and susceptibility to infection. The lack of growth potential of these four options is particularly important in pediatric cardiac surgery, where patients will often outgrow their vascular grafts and require additional operations. Thus, developing a material with sufficient durability and growth potential that will function as the child grows older will eliminate the need for reoperation and significantly reduce morbidity and mortality of some types of congenital heart defects. Vascular tissue engineering is a relatively new field that has undergone enormous growth over the last decade. The goal of vascular tissue engineering is to produce neovessels and neo-organ tissue from autologous cells using a biodegradable polymer as a scaffold. The most important advantage of tissue-engineered implants is that these tissues can grow, remodel, rebuild, and respond to injury. Once the seeded autologous cells have deposited an extracellular matrix and the original scaffold is biodegraded, the tissue resembles and behaves as native tissue. When tissue-engineered vascular grafts are eventually put to use in the clinical arena, the quality of life in patients after surgery will be drastically improved.

Since the first tissue-engineered vascular graft (TEVG) was implanted in a child over a decade ago, growth in the field of vascular tissue engineering has been driven by clinical demand for improved vascular prostheses with performance and durability similar to an autologous blood vessel. Great strides were made in pediatric congenital heart surgery using the classical tissue engineering paradigm, and cell seeding of scaffolds in vitro remained the cornerstone of neotissue formation. Our second-generation bone marrow cell-seeded TEVG diverged from tissue engineering dogma with a design that induces the recipient to regenerate vascular tissue in situ. New insights suggest that neovessel development is guided by cell signals derived from both seeded cells and host inflammatory cells that infiltrate the graft. The identification of these signals and the regulatory interactions that influence cell migration, phenotype and extracellular matrix deposition during TEVG remodeling are yielding a next-generation TEVG engineered to guide neotissue regeneration without the use of seeded cells. These developments represent steady progress towards our goal of an off-the-shelf tissue-engineered vascular conduit for pediatric congenital heart surgery.

Over the past few decades, there have been significant advancements in the imaging techniques of positron emission tomography (PET) and single photon emission tomography (SPECT). These changes have allowed for the targeted imaging of cellular processes and the development of hybrid imaging systems (e.g., SPECT/CT and PET/CT), which provide both functional and structural images of biological systems. One area that has garnered particular attention is angiogenesis as it relates to ischemic heart disease and limb ischemia. Though the aforementioned techniques have benefits and consequences, they enable scientists and clinicians to identify regions that are vulnerable to or have been exposed to ischemic injury via non-invasive means. This literature review highlights the advancements in molecular imaging techniques and specific probes as they pertain to the process of angiogenesis in cardiovascular disease.

Background: Elderly patients diagnosed with acute cholecystitis (AC) may undergo both ultrasonography (US) and computed tomography (CT)., Methods: A total of 475 patients (age, >64 y) with AC were included., Results: Groups included US alone (n = 240), CT alone (n = 60), and CT + US (n = 168). Sixty patients (35.7%) in the US + CT group had inflammation in both studies, 34 (20.2%) had inflammation only on US, and 32 (19.0%) had inflammation only on CT. In the US + CT group, detection of cholelithiasis was not different, but mean common bile duct size did not correlate. There was no difference among the groups in age, sex, medical service admission, nonambulatory status, dementia, diabetes, or coronary artery disease. Peritonitis, leukocytosis, and acidosis were more frequent in the 2 groups undergoing CT. The cholecystectomy rate was lowest (and the complication rate was highest) in the CT + US group., Conclusions: CT often is used in the diagnosis of AC in the elderly, especially those with more acute presentations. CT and US findings may be complementary in AC., (Copyright © 2011 Elsevier Inc. All rights reserved.)

The murine smoke-induced model produces histologic emphysema. The authors sought to assess whether the structural emphysema that occurred correlated with the development of compliance changes. The study exposed 2 strains of mice (CBA/J/J x C57BL/6J and A/J) to chronic cigarette smoke. Lung compliance and morphometry were measured. The smoking model generated significant emphysema in A/J mice in the absence of changes in compliance, lung matrix, or apoptosis. Importantly, there was no correlation between the emphysema measured by lung morphometry and pulmonary compliance. This lack of correlation suggests that the mechanisms involved in anatomic emphysema may be distinct from those that cause the loss of elastic recoil.

A battery of psychometric and performance tests was administered to 25 subjects who were classified into able-bodied (n = 8), brain-injured (n = 10), and spinal cord injured groups (n = 7). All disabled subjects were regarded by their referring rehabilitation therapists as potential candidates for driver assessment. Data were analyzed to identify which measures were useful in differentiating among the groups and predicting driving performance. Results indicated that psychometric measures can be useful in predicting driving performance among disabled drivers. Nearly all the measures in the battery were significant predictors of driving ability, and some were highly predictive. The best was the oral version of the Symbol Digit Modalities test, which by itself accounted for 70% of the variance of the full-sized-vehicle driving score. Adding a second variable into a two-step multiple regression further increased the correlation between predictors and driving, accounting for almost 80% of the variance in driving score. These findings support the feasibility of developing a simple test battery to determine which disabled candidates are ready for in-vehicle assessment, and which candidates are not ready without further evaluation of cognitive and performance skills.