A Contemporary Evaluation of Urological Outcomes After Renal Transplantation.

INTRODUCTION: Urological surgery after renal transplantation leaves patients at risk of infection and further urological complications. Our objective was to discern patient factors associated with adverse outcomes following renal transplantation to identify patients who would benefit from close urological follow-up. METHODS: Retrospective chart review was conducted for patients undergoing renal transplantation between August 1, 2016 and July 30, 2019 at a tertiary care academic center. Data on patient demographics, medical history, and surgical history were collected. Primary outcomes observed were urinary tract infection, urosepsis, urinary retention, unexpected urology visit, and urological procedures within 3 months of transplant. Variables determined significant by hypothesis testing were used in logistic regression modeling for each primary outcome. RESULTS: Of the 789 renal transplant patients, 217 (27.5%) developed postoperative urinary tract infection and 124 (15.7%) developed postoperative urosepsis. Patients with postoperative urinary tract infection were more likely to be female (OR 2.2, P < .01), have pre-existing prostate cancer (OR 3.1, P < .01), and recurrent urinary tract infections (OR 2.1, P < .01). After renal transplant, unexpected urology visits were observed in 191 (24.2%) patients, and urological procedures were performed in 65 (8.2%) patients. Postoperative urinary retention was noted in 47 (6.0%) patients and seen more often in patients with benign prostatic hyperplasia (OR 2.8, P = .033) and prior prostate surgery (OR 3.0, P = .072). CONCLUSIONS: Identifiable risk factors associated with urological complications after renal transplantation include benign prostatic hyperplasia, prostate cancer, urinary retention, and recurrent urinary tract infections. Female renal transplant patients are at increased risk of postoperative urinary tract infection and urosepsis. These patient subsets would benefit from establishing urological care and pre-transplant urological evaluation including urinalysis, urine cultures, urodynamic studies, and close follow-up post-transplant.

Mitral Valve Translocation: A Novel Operation for the Treatment of Secondary Mitral Regurgitation.

BACKGROUND: Conventional annuloplasty repair of secondary (functional) ischemic mitral regurgitation (IMR) is associated with a 60% recurrence of moderate or greater mitral regurgitation at 2 years. We developed a novel repair technique for IMR that addresses the underlying geometric alterations of the mitral valve apparatus and compared outcomes with those of conventional repair in a swine model. METHODS: Chronic IMR was induced by percutaneous embolization of the circumflex artery. Swine with severe IMR (median 9 weeks after infarction) underwent undersized rigid annuloplasty (n = 5) or translocation repair (n = 6). Translocation repair consisted of detaching the mitral valve en bloc at the annulus, creating a 1 cm wide frustum-shaped pericardial patch, and suturing the outer circumference of the patch to the annulus and inner circumference to the mitral valve. RESULTS: Operative survival was 92% (11 of 12). All animals had none/trace residual central mitral regurgitation, and mean inflow gradients were similar (1 mm Hg [interquartile range, 1 to 2] vs 2 mm Hg [interquartile range, 1 to 2]; P = .75) in the annuloplasty and translocation groups, respectively. Median coaptation length marginally improved in conventional swine (3 to 4 mm, P = .05), but dramatically improved in translocation swine (3 to 8 mm, P = .003). Posterior leaflet angle increased from 39 to 80 degrees (P = .05) in annuloplasty swine but decreased from 50 to 31 degrees (P = .03) in translocation swine. The posterior leaflet was immobile after annuloplasty but had preserved motion after translocation (excursion, 1 degree vs 24 degrees; P = .045). CONCLUSIONS: Mitral valve translocation effectively treats mitral regurgitation by relieving leaflet tethering. Compared with annuloplasty, mitral valve translocation creates a larger surface of coaptation and preserves leaflet mobility without compromising diastolic function.

dV-Trainer vs. da Vinci Simulator: Comparison of Virtual Reality Platforms for Robotic Surgery.

BACKGROUND: A virtual reality (VR) curriculum performed on the da Vinci Simulation System (DVSS) was previously shown to be effective in training fellows. The dV-Trainer is a separate platform with similar features to the da Vinci console, but its efficacy and utility versus the DVSS simulator are not well known. MATERIALS AND METHODS: A mastery-based VR curriculum was completed by surgical fellows on the DVSS (2014-2016) and on the dV-Trainer (2016-2018) at a large academic center. Pre-test/post-test scores were used to evaluate performance between the two groups. Data was collected prospectively. RESULTS: Forty-six fellows enrolled in the curriculum: surgical oncology (n=31), hepatobiliary (n=5), head/neck (n=4), endocrine (n=2), cardiothoracic (n=2), gynecology (n=1) and transplant surgery (n=1). Twenty-four used the DVSS and twenty-two used the dV-Trainer. Compared to the DVSS, the dV-Trainer was associated with lower scores on 2 of 3 VR modules in the pre-test (P=0.027, P<0.001, respectively) and post-test (P=0.021, P<0.001, respectively). Fellows in the dV-Trainer era scored lower on inanimate drills as well. Average VR curriculum score was lower on the dV-Trainer (71.3% vs 83.34%, P<0.001). dV-Trainer users spent more time completing the pre-test and post-test; however, overall simulator time to complete the curriculum was not significantly different (297 vs 231 minutes, P=0.142). Both groups showed improvement in scores after completion of the VR curriculum. CONCLUSIONS: The dV-Trainer simulator allows for more usability outside the operating room to complete VR modules; however, the DVSS simulator group outperformed the dV-Trainer group on the post-test.

Mentorship and formal robotic proficiency skills curriculum improve subsequent generations' learning curve for the robotic distal pancreatectomy.

BACKGROUND: Minimally invasive distal pancreatectomy is the accepted standard of care. The robotic distal (RDP) learning curve is 20-40 surgeries with operating time (ORT) as the most significant factor. This study evaluates how formal mentorship and a robotic skills curriculum impact the learning curve for subsequent generation surgeons. METHODS: Consecutive RDP from 2008 to 2017 were evaluated. First Generation was two surgeons who started program without training or mentorship. Second Generation was the two surgeons who joined the program with mentorship. Third Generation was fellows who benefited from both formal training and mentorship. Multivariable models (MVA) were performed for ORT, clinically relevant pancreatic fistula (CR-POPF), and major complications (Clavien≥3). RESULTS: A total of 296 RDP were performed of which 187 did not include other procedures: First Generation (n = 71), Second Generation (n = 50), and Third Generation (n = 66). ORT decreased by generation (p < 0.001) without any differences in CR-POPF or Clavien≥3. On MVA, earlier generation (p = 0.019), pre-operative albumin (p = 0.001) and pancreatic adenocarcinoma (p = 0.019) were predictive of ORT. Increased BMI (p = 0.049) and neoadjuvant therapy (p = 0.046) were predictive of CR-POPF. Fellow participation at the console increased over time. CONCLUSION: Formal mentorship and a skills curriculum decreased the learning curve and complications were largely dependent on patient factors.

Will It Play in Peoria? A Pilot Study of a Robotic Skills Curriculum for Surgical Oncology Fellows.

INTRODUCTION: To implement a mastery-based robotic surgery curriculum using virtual reality (VR) and inanimate reality (IR) drills at multiple Complex General Surgical Oncology (CGSO) fellowships. PATIENTS AND METHODS: A prospective study of curriculum feasibility and efficacy was conducted at four CGSO fellowship sites. All sites had simulators, and kits were provided to perform 19 biotissue drills. Fellows from three non-UPMC sites (n = 15) in 2016-2018 were compared with fellows from University of Pittsburgh (UPMC; n = 15) where the curriculum was validated in 2014-2018. RESULTS: All fellows completed the pre- and post-test. There was no difference in pre-test scores between UPMC and non-UPMC sites. Only 7 of 15 non-UPMC fellows completed the VR curriculum (47% compliance) compared with all 15 UPMC fellows completing the VR curriculum (100% compliance). UPMC had higher curriculum times (217 versus 93 mins) and % mastery (86% versus 55%). Time spent on curriculum was associated with % mastery (p = 0.01). Both groups showed improvement between pre- and post-test. Post-test VR scores trended higher for UPMC (221 versus 180). Between the non-UPMC sites, there was a difference in compliance (p = 0.03) and % mastery (p = 0.03). Zero non-UPMC fellows performed the biotissue drills, while five contemporary UPMC fellows completed 253 biotissue drills. Approximately 140 UPMC faculty and 300 staff hours were spent on the pilot. CONCLUSIONS: A proficiency curriculum can result in improved robotic console skills. However, multiple barriers to implementation potentially exist, including availability of simulators, availability of a training robot, on-site support staff, and universal buy-in from fellows, faculty, and leadership.

Initial Clinical Experience With Mitral Valve Translocation for Secondary Mitral Regurgitation.

BACKGROUND: Functional (secondary) mitral regurgitation (FMR) results from altered geometry of the mitral valve apparatus. Repair with restrictive mitral annuloplasty is associated with high rates of recurrent mitral regurgitation (MR). We developed a novel operative repair for FMR that translocates the intact mitral valve towards the apex. METHODS: The mitral valve was detached circumferentially and translocated into the ventricle with a frustum-shaped glutaraldehyde-treated autologous pericardial patch. Clinical and echocardiographic follow-up was performed. RESULTS: Fifteen consecutive patients with FMR (mean age, 59 years; 67% female) had mitral valve translocation between 2018 and 2020. Preoperative mean ejection fraction, left ventricular end-diastolic dimension, and systolic pulmonary artery pressure were 40% ± 11%, 59 ± 8 mm, and 49 ± 21 mm Hg, respectively; 33% had atrial fibrillation. Cardiomyopathy was ischemic in 4 and nonischemic in 11. Concomitant procedures included tricuspid valve operation (n = 8), coronary artery bypass grafting (n = 4), and atrial fibrillation ablation (n = 5). Post bypass transesophageal echocardiogram demonstrated none/trace MR in all patients and mean gradient of 3 mm Hg (interquartile range, 2-4 mm Hg). Mean leaflet extent of coaptation was 14 ± 2 mm (range, 11-17 mm). There was no postoperative mortality, stroke, or renal failure. Predismissal echocardiography showed none/trace MR in 14 patients and mild MR in 1. One patient underwent successful late rerepair of a suture line leak. Twelve patients were alive at latest follow-up and MR at 1 and 6 months was mild or less in all patients with mean leaflet extent of coaptation of 14 ± 2 mm (range, 12-16 mm) at 6 months. CONCLUSIONS: Mitral valve translocation creates a large surface of coaptation and effectively corrects FMR. Further study is needed to demonstrate the long-term durability and clinical utility of this operation.

Development of a Reproducible Swine Model of Chronic Ischemic Mitral Regurgitation: Lessons Learned.

BACKGROUND: Durability of mitral valve repair for ischemic mitral regurgitation (IMR) remains poor. We established a swine model of chronic IMR, and describe the methods and lessons learned from this model. METHODS: Thirty-five swine underwent percutaneous myocardial infarction with ethanol ablation of the circumflex or obtuse marginal (OM) arteries. Swine were followed with routine echocardiography for the development of severe IMR. Once severe IMR was established, swine underwent mitral valve operations on cardiopulmonary bypass. After operation, swine were survived up to 7 weeks. Angiographic and echocardiographic features of swine who developed severe IMR (IMR swine) and those who did not (non-IMR swine) were compared. RESULTS: The median number of OM arteries was 3, with 2 OM arteries infarcted. Acute survival after the myocardial infarction was 74% (26 of 35) with 3 (9%) early, postoperative deaths. Among the 23 swine with follow-up to determine IMR status, 14 of 23 (61%) developed significant IMR. Among IMR pigs, left ventricular (LV) ejection fraction decreased from 65% pre-myocardial infarction to 45% pre-mitral valve intervention (P < .001). Among non-IMR swine, LV ejection fraction decreased nonsignificantly from baseline (60%) to latest follow-up (55%) (P = .443). LV end-diastolic dimension (P = .039), wall motion score (P = .027), global circumferential strain (P = .014), and global longitudinal strain (P = .023) were significantly worse in IMR compared with non-IMR swine. CONCLUSIONS: A reproducible percutaneous model of severe IMR in swine is feasible with a guided anesthetic and perioperative approach. This model can serve as a platform to better understand the mechanism of IMR and subsequently to test novel repair techniques.

Association of Mentorship and a Formal Robotic Proficiency Skills Curriculum With Subsequent Generations' Learning Curve and Safety for Robotic Pancreaticoduodenectomy.

Importance: Learning curves are unavoidable for practicing surgeons when adopting new technologies. However, patient outcomes are worse in the early stages of a learning curve vs after mastery. Therefore, it is critical to find a way to decrease these learning curves without compromising patient safety. Objective: To evaluate the association of mentorship and a formal proficiency-based skills curriculum with the learning curves of 3 generations of surgeons and to determine the association with increased patient safety. Design, Setting, and Participants: All consecutive robotic pancreaticoduodenectomies (RPDs) performed at the University of Pittsburgh Medical Center between 2008 and 2017 were included in this study. Surgeons were split into generations based on their access to mentorship and a proficiency-based skills curriculum. The generations are (1) no mentorship or curriculum, (2) mentorship but no curriculum, and (3) mentorship and curriculum. Univariable and multivariable analyses were used to create risk-adjusted learning curves by surgical generation and to analyze factors associated with operating room time, complications, and fellows completing the full resection. The participants include surgical oncology attending surgeons and fellows who participated in an RPD at University of Pittsburgh Medical Center between 2008 and 2017. Main Outcomes and Measures: The primary outcome was operating room time (ORT). Secondary outcomes were postoperative pancreatic fistula and Clavien-Dindo classification higher than grade 2. Results: We identified 514 RPDs completed between 2008 and 2017, of which 258 (50.2%) were completed by first-generation surgeons, 151 (29.3%) were completed by the second generation, and 82 (15.9%) were completed by the third generation. There was no statistically significant difference between groups with respect to age (66.3-67.3 years; P = .52) or female sex (n = 34 [41.5%] vs n = 121 [46.9%]; P = .60). There was a significant decrease in ORT (P < .001), from 450.8 minutes for the first-generation surgeons to 348.6 minutes for the third generation. Additionally, across generations, Clavien-Dindo classification higher than grade 2 (n = 74 [28.7%] vs n = 30 [9.9%] vs n = 12 [14.6%]; P = .01), conversion rates (n = 18 [7.0%] vs n = 7 [4.6%] vs n = 0; P = .006), and estimated blood loss (426 mL vs 288.6 mL vs 254.7 mL; P < .001) decreased significantly with subsequent generations. There were no significant differences in postoperative pancreatic fistula. Conclusions and Relevance: In this study, ORT, conversion rates, and estimated blood loss decreased across generations without a concomitant rise in adverse patient outcomes. These findings suggest that a proficiency-based curriculum coupled with mentorship allows for the safe introduction of less experienced surgeons to RPD without compromising patient safety.

Sutureless Closure of Arterial Cannulation Sites.

OBJECTIVE: Percutaneous femoral cannulation for venoarterial extracorporeal membrane oxygenation (ECMO) is commonly performed but percutaneous removal of arterial cannulas has not been broadly accepted. We hypothesized that a system that allows endovascular access to ECMO circuits along with the MANTA® large-bore vascular closure device could be used to successfully close arterial ECMO cannulation sites in a large animal model. METHODS: Yorkshire swine (40 to 60 kg, n = 2) were used for this study. In the first swine, the infrarenal abdominal aorta was exposed. The aorta was cannulated once using a 15 Fr cannula and twice with a 19 Fr arterial cannula. A novel adaptor system that facilitates endovascular access to ECMO circuits was connected, and a 0.035″ Benston wire was placed through the adaptor and guided into the aorta. The cannula was removed over the wire and manual pressure was applied. The MANTA® sheath was inserted over the wire followed by the closure unit and was deployed. The process was repeated at 2 separate sites. A similar experiment was performed in a second swine, but through a median sternotomy to cannulate the ascending aorta. RESULTS: Good hemostasis was achieved at all cannulation sites. Angiography demonstrated unobstructed flow across all closure sites with no evidence of extravasation. CONCLUSIONS: The data presented here support the use of the MANTA® vascular closure device for the closure of arterial cannulation sites following ECMO decannulation and demonstrates utility of a novel adaptor system for establishing endovascular access in this context.

Methodology for Developing an Educational and Research Video Library in Minimally Invasive Surgery.

OBJECTIVE: Explore the methods used and costs necessary for the creation and maintenance of a surgical video library with an emphasis on its applications in surgical education and scholarship. DESIGN: A methodology paper highlighting how to develop and utilize a surgical video library for trainee operative preparation, development of research projects, and surgeon credentialing. SETTING: The study was conducted at the University of Pittsburgh Medical Center, a tertiary care medical center. PARTICIPANTS: Not applicable. RESULTS: The video library includes all recorded robotic operations performed by the Division of Surgical Oncology at the University of Pittsburgh from 2010 to 2018. It includes 929 videos of which 110 selected videos are uploaded for trainee review online to prepare for upcoming operations. These procedures are broken into steps to create intraoperative time metrics for trainee integration. Fellows operated from console in 85% of robotic cases and all 30 fellows could obtain robotic privileges based on case logs. To date 102 short scholarly videos have been created: 7 for manuscripts, 13 as video submissions, 27 in book chapters, and 55 for presentations. Three papers have been published using video review to determine clinical outcomes with four more under evaluation. The cost of the program is <$10,000 annually. CONCLUSIONS: Video libraries can be efficiently created utilizing intraoperative recorders for minimally invasive surgery. Breaking surgeries into distinct steps can aid in deliberate integration and answer clinical questions. Overall video libraries are cost effective tools for trainee education, research, and ultimately surgeon credentialing.

Crowdsourced Assessment of Inanimate Biotissue Drills: A Valid and Cost-Effective Way to Evaluate Surgical Trainees.

OBJECTIVE: Providing feedback to surgical trainees is a critical component for assessment of technical skills, yet remains costly and time consuming. We hypothesize that statistical selection can identify a homogenous group of nonexpert crowdworkers capable of accurately grading inanimate surgical video. DESIGN: Applicants auditioned by grading 9 training videos using the Objective Structured Assessment of Technical Skills (OSATS) tool and an error-based checklist. The summed OSATS, summed errors, and OSATS summary score were tested for outliers using Cronbach's Alpha and single measure intraclass correlation. Accepted crowdworkers then submitted grades for videos in 3 different compositions: full video 1× speed, full video 2× speed, and critical section segmented video. Graders were blinded to this study and a similar statistical analysis was performed. SETTING: The study was conducted at the University of Pittsburgh Medical Center (Pittsburgh, PA), a tertiary care academic teaching hospital. PARTICIPANTS: Thirty-six premedical students participated as crowdworker applicants and 2 surgery experts were compared as the gold-standard. RESULTS: The selected hire intraclass correlation was 0.717 for Total Errors and 0.794 for Total OSATS for the first hire group and 0.800 for Total OSATS and 0.654 for Total Errors for the second hire group. There was very good correlation between full videos at 1× and 2× speed with an interitem statistic of 0.817 for errors and 0.86 for OSATS. Only moderate correlation was found with critical section segments. In 1 year 275hours of inanimate video was graded costing $22.27/video or $1.03/minute. CONCLUSIONS: Statistical selection can be used to identify a homogenous cohort of crowdworkers used for grading trainees' inanimate drills. Crowdworkers can distinguish OSATS metrics and errors in full videos at 2× speed but were less consistent with segmented videos. The program is a comparatively cost-effective way to provide feedback to surgical trainees.

Correction to: Evolution of a Novel Robotic Training Curriculum in a Complex General Surgical Oncology Fellowship.

In the XML of the original article, L. Mark Knab's first name was tagged incorrectly.

Evolution of a Novel Robotic Training Curriculum in a Complex General Surgical Oncology Fellowship.

BACKGROUND: Robotic surgery is increasingly being used for complex oncologic operations, although currently there is no standardized curriculum in place for surgical oncologists. We describe the evolution of a proficiency-based robotic training program implemented for surgical oncology fellows, and demonstrate the outcomes of the program. METHODS: A 5-step robotic curriculum began integration in July 2013. Fellows from July 2013 to August 2017 were included. An education portfolio was created for each fellow, including pre-fellowship experience, fellowship experience with data from robotic curriculum and operative experience, and post-fellowship practice information. RESULTS: Of 30 fellows, 20% completed a prior fellowship, 97% trained at an academic residency, 57% had prior robotic training (median 5 h), and 43% had performed robotic surgery (median 0 cases). In fellowship, on average, fellows spent 5 h on the virtual reality curriculum and performed 19 biotissue anastomoses. For total surgeries, fellows operating from the console increased over time (p = 0.005). For pancreas, the average percentage of robotic pancreaticoduodenectomy (PD) steps completed increased (p < 0.011), as did the number of PDs in which the fellow completed the entire resection (p = 0.013). Fellows were 10 times more likely to complete the entire distal than PD from the console (p < 0.01). Post-fellowship, 83% of fellows obtained an academic position, 88% utilized robotics, and 91% performed pancreatic surgery. CONCLUSIONS: With dedicated training, fellows can safely primarily perform complex gastrointestinal robotic surgeries and, after graduation, take jobs incorporating this skill set. In this era of scrutiny on cost and outcomes, specialized training programs offer a safe integration option for complex technical skills.

Engineering a living biomaterial via bacterial surface capture of environmental molecules.

Synthetic biology holds significant potential in biomaterials science as synthetically engineered cells can produce new biomaterials, or alternately, can function as living components of new biomaterials. Here, we describe the creation of a new biomaterial that incorporates living bacterial constituents that interact with their environment using engineered surface display. We first developed a gene construct that enabled simultaneous expression of cytosolic mCherry and a surface-displayed, catalytically active enzyme capable of covalently bonding with benzylguanine (BG) groups. We then created a functional living material within a microfluidic channel using these genetically engineered cells. The material forms when engineered cells covalently bond to ambient BG-modified molecules upon induction. Given the wide range of materials amenable to functionalization with BG-groups, our system provides a proof-of-concept for the sequestration and assembly of BG-functionalized molecules on a fluid-swept, living biomaterial surface.

Creating biological nanomaterials using synthetic biology.

Synthetic biology is a new discipline that combines science and engineering approaches to precisely control biological networks. These signaling networks are especially important in fields such as biomedicine and biochemical engineering. Additionally, biological networks can also be critical to the production of naturally occurring biological nanomaterials, and as a result, synthetic biology holds tremendous potential in creating new materials. This review introduces the field of synthetic biology, discusses how biological systems naturally produce materials, and then presents examples and strategies for incorporating synthetic biology approaches in the development of new materials. In particular, strategies for using synthetic biology to produce both organic and inorganic nanomaterials are discussed. Ultimately, synthetic biology holds the potential to dramatically impact biological materials science with significant potential applications in medical systems.