Use of In-Situ Simulation Based Clinical Systems Test of Thoracic Robotic Surgery Emergencies.

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.

Paraconduit Hiatal Hernia Following Esophagectomy: Incidence, Risk Factors, Outcomes and Repair.

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.

COVID-19 Tracheostomy: Experience in a University Hospital With Intermediate Follow-up.

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.

Evaluation of remodeling process in small-diameter cell-free tissue-engineered arterial graft.

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.

Clinical outcomes and staff satisfaction after adoption of digital chest drainage system for minimally invasive lung resections.

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.

Preoperative risk factors for anastomotic leak after esophagectomy with gastric reconstruction: A 6-year national surgical quality improvement (NSQIP) database analysis.

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.

Enhanced recovery after surgery pathway leads to decreased length of stay for patients undergoing minimally invasive lung resection.

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 1st, 2015 and October 26th, 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.

A pilot study of robotic surgery case videos for first-year medical student anatomy.

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.

Video- and Robotic-Assisted Thoracoscopic Truncal Vagotomy.

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.

COVID-19-induced Esophageal Necrosis Requiring Emergent Total Esophagectomy in a Vaccinated Patient.

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.

Targeted molecular imaging of angiogenesis in PET and SPECT: a review.

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.

Thymectomy for treatment of anti-NMDA receptor encephalitis.

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.

Liquid-based rapid onsite evaluation of endobronchial ultrasound cytologies.

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.

Regional heterogeneity in determinants of atrial matrix remodeling and association with atrial fibrillation vulnerability postmyocardial infarction.

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.

National Survey of Burnout and Distress Among Cardiothoracic Surgery Trainees.

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.

Robot-Assisted Thoracoscopic Mediastinal Parathyroidectomy: A Single Surgeon Case Series.

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); Ca2+: 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.

Molecular Imaging of Factor XIII Activity for the Early Detection of Mouse Coronary Microvascular Disease.

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 (99mTc-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.

Differential outcomes of venous and arterial tissue engineered vascular grafts highlight the importance of coupling long-term implantation studies with computational modeling.

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.

Beyond 250: A Comprehensive Strategy to Maximize the Operative Experience for Junior Residents.

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.