Contrast-enhanced computed tomography for ex vivo assessment of human kidneys: A proof-of-concept study.

BACKGROUND: Ex vivo perfusion of transplant-declined human organs has emerged as a promising platform to study the response of an organ to novel therapeutic strategies. However, to fully realize the capability of this platform for performing translational research in human organ pathophysiology, there is a need for robust assays to assess organ function and disease. State-of-the-art research methods rely on analyses of biopsies taken during perfusion, which both damages the organ and only provides localized information. Developing non-invasive, whole organ methods of assessment is critical to the further development of this research platform. METHODS: We use ex vivo cold infusion scanning (EXCIS) with contrast-enhanced computed tomography (CT) to quantify perfusion in kidneys preserved ex vivo. EXCIS-CT computes three complementary metrics for whole organ assessment: a dynamic assessment of contrast filling, a measure of vascular network anatomical structure, and a static assessment of perfusion heterogeneity. RESULTS: These metrics were applied to a series of six transplant-declined human kidneys, which demonstrated a range of anatomies and perfusion. Lastly, two transplant-declined human kidneys were imaged before and after a 1-h period of ex vivo normothermic perfusion (NMP). We found variable responses to NMP, with one kidney maintaining the vascular network and hemodynamics and the other showing significant changes in vessel size and spatial perfusion profile. CONCLUSIONS: EXCIS-CT provides metrics that can be used to characterize whole organ perfusion and vascular function.

Frequency and Characteristics of Social Media Use among General Surgery Trainees.

INTRODUCTION: With increased social isolation due to COVID-19, social media has been increasingly adopted for communication, education, and entertainment. We sought to understand the frequency and characteristics of social media usage among general surgery trainees. MATERIALS AND METHODS: General surgery trainees in 15 American training programs were invited to participate in an anonymous electronic survey. The survey included questions about demographics, frequency of social media usage, and perceptions of risks and benefits of social media. Univariate analysis was performed to identify differences between high users of social media (4-7 h per week on at least one platform) and low users (0-3 h or less on all platforms). RESULTS: One hundred fifty-seven of 591 (26.6%) trainees completed the survey. Most respondents were PGY3 or lower (75%) and high users of social media (74.5%). Among high users, the most popular platforms were Instagram (85.7%), YouTube (85.1%), and Facebook (83.6%). YouTube and Twitter were popular for surgical education (77.3% and 68.2%, respectively). The most reported benefits of social media were improving patient education and professional networking (85.0%), where high users agreed more strongly about these benefits (P = 0.002). The most reported risks were seeing other residents (42%) or attendings (17%) with unprofessional behavior. High users disagreed more strongly about risks, including observing attendings with unprofessional behavior (P = 0.028). CONCLUSIONS: Most respondents were high users of social media, particularly Instagram, YouTube, and Facebook. High users incorporated social media into their surgical education while perceiving more benefits and fewer risks of social media.

Epidemiology and outcomes of surgical site infections among pediatric liver transplant recipients.

INTRODUCTION: Surgical site infections (SSI) are a significant cause of morbidity in liver transplant recipients, and the current data in the pediatric population are limited. The goal of this study was to identify the incidence, classification, risk factors, and outcomes of SSIs among children undergoing liver transplantation (LT). METHODS: A single-center, retrospective descriptive analysis was performed of patients age ≤18 years undergoing LT between September 2007 and April 2017. SSI identified within the first 30 days were analyzed. Primary endpoints included incidence, classification, risk factors, and outcomes associated with SSIs. RESULTS: We included 86 patients, eight patients (9.3%) developed SSIs. Among segmental grafts (SG) recipients, 7/61 (11.4%) developed SSI. Among whole grafts recipients, 1/25 (4%) developed SSI. SSIs were associated with the presence of biliary complications (35% vs. 3%, p < .01; odds ratios 24, 95% CI: 3.41-487.37, p<.01). There were no differences in long term graft or patient survival associated with SSI. Patients who developed SSI were more likely to undergo reoperation (50% vs. 16.7%, p = .045) and had an increased total number of hospital days in the first 60 days post-transplant (30.5 vs. 12.5 days, p = .001). CONCLUSIONS: SSIs after pediatric LT was less frequent than what has been previously reported in literature. SSIs were associated with the presence of biliary complications without an increase in mortality. SG had an increased rate of biliary complications without an association to SSIs but, considering its positive impact on organ shortage barriers, should not be a deterrent to the utilization of SGs.

Endothelial Cell-Derived Interleukin-18 Released During Ischemia Reperfusion Injury Selectively Expands T Peripheral Helper Cells to Promote Alloantibody Production.

BACKGROUND: Ischemia reperfusion injury (IRI) predisposes to the formation of donor-specific antibodies, a factor contributing to chronic rejection and late allograft loss. METHODS: We describe a mechanism underlying the correlative association between IRI and donor-specific antibodies by using humanized models and patient specimens. RESULTS: IRI induces immunoglobulin M-dependent complement activation on endothelial cells that assembles an NLRP3 (NOD-like receptor pyrin domain-containing protein 3) inflammasome via a Rab5-ZFYVE21-NIK axis and upregulates ICOS-L (inducible costimulator ligand) and PD-L2 (programmed death ligand 2). Endothelial cell-derived interleukin-18 (IL-18) selectively expands a T-cell population (CD4+CD45RO+PD-1hiICOS+CCR2+CXCR5-) displaying features of recently described T peripheral helper cells. This population highly expressed IL-18R1 and promoted donor-specific antibodies in response to IL-18 in vivo. In patients with delayed graft function, a clinical manifestation of IRI, these cells were Ki-67+IL-18R1+ and could be expanded ex vivo in response to IL-18. CONCLUSIONS: IRI promotes elaboration of IL-18 from endothelial cells to selectively expand alloreactive IL-18R1+ T peripheral helper cells in allograft tissues to promote donor-specific antibody formation.

First-in-Human Experience With Peritoneal Direct Sodium Removal Using a Zero-Sodium Solution: A New Candidate Therapy for Volume Overload.

BACKGROUND: Loop diuretics have well-described toxicities, and loss of response to these agents is common. Alternative strategies are needed for the maintenance of euvolemia in heart failure (HF). Nonrenal removal of sodium directly across the peritoneal membrane (direct sodium removal [DSR]) with a sodium-free osmotic solution should result in extraction of large quantities of sodium with limited off-target solute removal. METHODS: This article describes the preclinical development and first-in-human proof of concept for DSR. Sodium-free 10% dextrose was used as the DSR solution. Porcine experiments were conducted to investigate the optimal dwell time, safety, and scalability and to determine the effect of experimental heart failure. In the human study, participants with end-stage renal disease on peritoneal dialysis (PD) underwent randomization and crossover to either a 2-hour dwell with 1 L DSR solution or standard PD solution (Dianeal 4.25% dextrose, Baxter). The primary end point was completion of the 2-hour dwell without significant discomfort or adverse events, and the secondary end point was difference in sodium removal between DSR and standard PD solution. RESULTS: Porcine experiments revealed that 1 L DSR solution removed 4.1±0.4 g sodium in 2 hours with negligible off-target solute removal and overall stable serum electrolytes. Increasing the volume of DSR solution cycled across the peritoneum increased sodium removal and substantially decreased plasma volume (P=0.005). In the setting of experimental heart failure with elevated right atrial pressure, sodium removal was ≈4 times greater than in healthy animals (P<0.001). In the human proof-of-concept study, DSR solution was well tolerated and not associated with significant discomfort or adverse events. Plasma electrolyte concentrations were stable, and off-target solute removal was negligible. Sodium removal was substantially higher with DSR (4.5±0.4 g) compared with standard PD solution (1.0±0.3 g; P<0.0001). CONCLUSIONS: DSR was well tolerated in both animals and human subjects and produced substantially greater sodium removal than standard PD solution. Additional research evaluating the use of DSR as a method to prevent and treat hypervolemia in heart failure is warranted. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03801226.

What's it Worth?: The Costs and Benefits of an Initiative to Decrease Post-Call Fatigued Driving Among Surgery Residents.

BACKGROUND: In 2017 the ACGME enacted new regulations requiring sponsoring institutions to ensure "safe transportation options for residents who may be too fatigued to safely return home." We investigate here the impact of a pilot "Safe Ride" program designed to mitigate the risks of fatigued driving. METHODS: During a 2-month pilot period at a single university-affiliated general surgery residency with four urban clinical sites, all residents (n = 72) were encouraged to hire a rideshare (e.g., Uber, Lyft) to and from 24-h clinical shifts if they felt too fatigued to drive safely. The cost of the rideshare was fully reimbursed to the resident. The impact of this intervention was evaluated using utilization data and a post-intervention resident survey. RESULTS: A total of 16.6% of trainees utilized a rideshare at least one time. Sixty-three post-call rides were taken, predominantly by junior residents (92.4%) and for commutes greater than 15 miles (91%). The cost for the 60-day pilot was $3030. Comparing pre-intervention to post-intervention data, there was a significant improvement in the reported frequency of falling asleep or nearly asleep while driving (P < 0.001). Trainees nearly unanimously (98%) supported efforts to make the program permanent. DISCUSSION: Driving while fatigued is common among surgical residents, with increased risk among junior residents, during longer commutes and following longer shifts. A reimbursed rideshare program effectively targets these risk factors and was associated with a significant decrease in rates of self-reported fatigued driving. Future efforts should focus on strategies to promote use of reimbursed rideshare programs while remaining cost efficient.

Understanding the Barriers to Reporting Sexual Harassment in Surgical Training.

OBJECTIVE: To investigate the occurrence, nature, and reporting of sexual harassment in surgical training and to understand why surgical trainees who experience harassment might not report it. This information will inform ways to overcome barriers to reporting sexual harassment. SUMMARY/ BACKGROUND DATA: Sexual harassment in the workplace is a known phenomenon with reports of high frequency in the medical field. Aspects of surgical training leave trainees especially vulnerable to harassing behavior. The characteristics of sexual harassment and reasons for its underreporting have yet to be studied on the national level in this population. METHODS: An electronic anonymous survey was distributed to general surgery trainees in participating program; all general surgery training programs nationally were invited to participate. RESULTS: Sixteen general surgery training programs participated, yielding 270 completed surveys (response rate of 30%). Overall, 48.9% of all respondents and 70.8% of female respondents experienced at least 1 form of sexual harassment during their training. Of the respondents who experienced sexual harassment, 7.6% reported the incident. The most common cited reasons for nonreporting were believing that the action was harmless (62.1%) and believing reporting would be a waste of time (47.7%). CONCLUSION: Sexual harassment occurs in surgical training and is rarely reported. Many residents who are harassed question if the behavior they experienced was harassment or feel that reporting would be ineffectual-leading to frequent nonreporting. Surgical training programs should provide all-level education on sexual harassment and delineate the best mechanism for resident reporting of sexual harassment.

Results of COVID-minimal Surgical Pathway During Surge-phase of COVID-19 Pandemic.

OBJECTIVE: The outcomes of patients treated on the COVID-minimal pathway were evaluated during a period of surging COVID-19 hospital admissions, to determine the safety of continuing to perform urgent operations during the pandemic. SUMMARY OF BACKGROUND DATA: Crucial treatments were delayed for many patients during the COVID-19 pandemic, over concerns for hospital-acquired COVID-19 infections. To protect cancer patients whose survival depended on timely surgery, a "COVID-minimal pathway" was created. METHODS: Patients who underwent a surgical procedure on the pathway between April and May 2020 were evaluated. The "COVID-minimal surgical pathway" consisted of: (A) evolving best-practices in COVID-19 transmission-reduction, (B) screening patients and staff, (C) preoperative COVID-19 patient testing, (D) isolating pathway patients from COVID-19 patients. Patient status through 2 weeks from discharge was determined as a reflection of hospital-acquired COVID-19 infections. RESULTS: After implementation, pathway screening processes excluded 7 COVID-19-positive people from interacting with pathway (4 staff and 3 patients). Overall, 122 patients underwent 125 procedures on pathway, yielding 83 admissions (42 outpatient procedures). The median age was 64 (56-79) and 57% of patients were female. The most common surgical indications were cancer affecting the uterus, genitourinary tract, colon, lung or head and neck. The median length of admission was 3 days (1-6). Repeat COVID-19 testing performed on 27 patients (all negative), including 9 patients evaluated in an emergency room and 8 readmitted patients. In the postoperative period, no patient developed a COVID-19 infection. CONCLUSIONS: A COVID-minimal pathway comprised of physical space modifications and operational changes may allow urgent cancer treatment to safely continue during the COVID-19 pandemic, even during the surge-phase.

Measuring Uncertainty Intolerance in Surgical Residents Using Standardized Assessments.

BACKGROUND: Physicians are frequently called on to make medical decisions despite being uncertain about the outcomes of these choices. The psychological stress associated with these dilemmas, known as "Uncertainty Intolerance" (UI), can significantly impact the quality of a physician's practice as well as their own mental health. Coping with uncertainty is an important competency that all residents must master, and some residency programs are introducing new education initiatives aimed at improving UI. However, currently there is no standard protocol for measuring UI or the effectiveness of such interventions and there are no established methods for identifying the residents who would most benefit from the training. In this study, we aim to use the Physician Reaction to Uncertainty (PRU) and Physician Risk Attitude (PRA) scales as assessments for UI in surgical residents, and to determine if Myers-Briggs Type Indicator (MBTI) personality factors are associated with PRU and PRA scores and can be used to identify residents who are more likely to have higher UI. MATERIALS AND METHODS: The PRU and PRA scales, and the MBTI assessment were administered to a total pool of 71 general surgery residents. In addition to the survey questions, residents provided information regarding their gender (male or female), and stage of training (junior or senior). RESULTS: In total, 45 male residents and 25 female residents completed the PRA and PRU scales (98.6%). There were no statistically significant differences when comparisons were made between junior and senior residents or male and female residents. Thirty seven male residents and 18 female residents also completed the MBTI assessment (80.4% and 72%, respectively). PRU and PRA scores were analyzed with respect to personality factors to determine if certain dichotomies are associated with increased UI. There was a trend toward higher UI in individuals identifying with Judging. CONCLUSIONS: In this study, we have conducted a pilot study using the PRU and PRA scales to measuring the success of our new education initiatives aimed at improving uncertainty tolerance. We found that the PRU and PRA assessments were simple to administer and had a high completion rate. Our findings also suggest that individuals who identify with Judging may better tolerate the uncertainties associated with surgical practice, although larger studies will be required to determine if MBTI factors are linked to UI in surgical residents.

Higher risk of urinary tract infections in renal transplant recipients receiving pentamidine versus trimethoprim-sulfamethoxazole (TMP-SMX) for Pneumocystis pneumonia prophylaxis.

Urinary tract infection (UTI) is one of the most common infectious complications among renal transplant patients. Trimethoprim-sulfamethoxazole (TMP-SMX) is routinely used as first-line prophylaxis against Pneumocystis pneumonia (PCP) and other opportunistic infections including UTI. Aerosolized pentamidine is an alternate agent used for PCP prophylaxis; however, it does not provide coverage against uropathogens. This is a retrospective study of 81 renal transplant recipients who received TMP-SMX or aerosolized pentamidine for PCP prophylaxis at our center over 1 year. Survival analysis demonstrated increased cumulative incidence of UTI among patients receiving pentamidine for PCP prophylaxis compared to those receiving TMP-SMX (log-rank test P < .001). Univariate and multivariate Cox proportional hazard regression model showed pentamidine prophylaxis (HR 3.740; 95% CI 1.745-8.016; P = .001) and female sex (HR 4.025; 95% CI 1.770-9.154; P = .001) to independently increase UTI risk. Age, induction agent, graft type, diabetes, and delayed graft function (DGF) were not associated with increased risk. This study concludes that the use of pentamidine for PCP prophylaxis compared to TMP-SMX is associated with increased risk of UTI. Secondary UTI prophylaxis may be considered for patients who are unable to tolerate TMP-SMX and who have other risk factors for UTI; however, the efficacy of this has not been studied.