Positron emission tomography myocardial perfusion imaging (PET MPI) findings predictive of post-liver transplant major adverse cardiac events

Positron emission tomography myocardial perfusion imaging (PET MPI) is a noninvasive diagnostic test capable of detecting coronary artery disease, structural heart disease, and myocardial flow reserve (MFR). We aimed to determine the prognostic utility of PET MPI to predict post-liver transplant (LT) major adverse cardiac events (MACE). Among the 215 LT candidates that completed PET MPI between 2015 and 2020, 84 underwent LT and had 4 biomarker variables of clinical interest on pre-LT PET MPI (summed stress and difference scores, resting left ventricular ejection fraction, global MFR). Post-LT MACE were defined as acute coronary syndrome, heart failure, sustained arrhythmia, or cardiac arrest within the first 12 months post-LT. Cox regression models were constructed to determine associations between PET MPI variable/s and post-LT MACE. The median LT recipient age was 58 years, 71% were male, 49% had NAFLD, 63% reported prior smoking, 51% had hypertension, and 38% had diabetes mellitus. A total of 20 MACE occurred in 16 patients (19%) at a median of 61.5 days post-LT. One-year survival of MACE patients was significantly lower than those without MACE (54% vs. 98%, p =0.001). On multivariate analysis, reduced global MFR ≤1.38 was associated with a higher risk of MACE [HR=3.42 (1.23-9.47), p =0.019], and every % reduction in left ventricular ejection fraction was associated with an 8.6% higher risk of MACE [HR=0.92 (0.86-0.98), p =0.012]. Nearly 20% of LT recipients experienced MACE within the first 12 months of LT. Reduced global MFR and reduced resting left ventricular ejection fraction on PET MPI among LT candidates were associated with increased risk of post-LT MACE. Awareness of these PET-MPI parameters may help improve cardiac risk stratification of LT candidates if confirmed in future studies.

Successful living donor liver transplantation in a patient with hemophilia A and factor VIII inhibitor: a case report with perioperative recommendations

Liver transplantation in patients with end-stage liver disease and coexisting hemophilia A has been described. Controversy exists over perioperative management of patients with factor VIII inhibitor predisposing patients to hemorrhage. We describe the case of a 58-year-old man with a history of hemophilia A and factor VIII inhibitor, eradicated with rituximab prior to living donor liver transplantation without recurrence of inhibitor. We also provide perioperative management recommendations from our successful multidisciplinary approach.

Assessment of Surgeon Performance of Advanced Open Surgical Skills Using a Microskills-Based Novel Curriculum

IMPORTANCE

The increase in minimally invasive surgical procedures has eroded exposure of general surgery residents to open operations. High-fidelity simulation, together with deliberate instruction, is needed for advanced open surgical skill (AOSS) development.

OBJECTIVE

To collect validity evidence for AOSS tools to support a shared model for instruction.

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study included postresidency surgeons (PRSs) and second-year general surgery residents (R2s) at a single academic medical center who completed simulated tasks taught within the AOSS curriculum between June 1 and October 31, 2021.

EXPOSURES

The AOSS curriculum includes 6 fine-suture and needle handling tasks, including deep suture tying (with and without needles) and continuous suturing using the pitch-and-catch and push-push-pull techniques (both superficial and deep). Teaching and assessment are based on specific microskills using a 3-dimensional printed iliac fossa model.

MAIN OUTCOMES AND MEASURES

The PRS group was timed and scored (5-point Likert scale) on 10 repetitions of each task. Six months after receiving instruction on the AOSS tasks, the R2 group was similarly timed and scored.

RESULTS

The PRS group included 14 surgeons (11 male [79%]; 8 [57%] attending surgeons) who completed the simulation; the R2 group, 9 surgeons (5 female [55%]) who completed the simulation. Score and time variability were greater for the R2s compared with the PRSs for all tasks. The R2s scored lower and took longer on (1) deep pitch-and-catch suturing (69% of maximum points for a mean [SD] of 142.0 [31.7] seconds vs 77% for a mean [SD] of 95.9 [29.4] seconds) and deep push-push-pull suturing (63% of maximum points for a mean [SD] of 284.0 [72.9] seconds vs 85% for a mean [SD] of 141.4 [29.1] seconds) relative to the corresponding superficial tasks; (2) suture tying with a needle vs suture tying without a needle (74% of maximum points for a mean [SD] of 64.6 [19.8] seconds vs 90% for a mean [SD] of 54.4 [15.6] seconds); and (3) the deep push-push-pull vs pitch-and-catch techniques (63% of maximum points for a mean [SD] of 284.0 [72.9] seconds vs 69% of maximum points for a mean [SD] of 142.0 [31.7] seconds). For the PRS group, time was negatively associated with score for the 3 hardest tasks: superficial push-push-pull (ρ = 0.60; P = .02), deep pitch-and-catch (ρ = 0.73; P = .003), and deep push-push-pull (ρ = 0.81; P < .001). For the R2 group, time was negatively associated with score for the 2 easiest tasks: suture tying without a needle (ρ = 0.78; P = .01) and superficial pitch-and-catch (ρ = 0.79; P = .01).

CONCLUSIONS AND RELEVANCE

The findings of this cohort study offer validity evidence for a novel AOSS curriculum; reveal differential difficulty of tasks that can be attributed to specific microskills; and suggest that position on the surgical learning curve may dictate the association between competency and speed. Together these findings suggest specific, actionable opportunities to guide instruction of AOSS, including which microskills to focus on, when individual rehearsal vs guided instruction is more appropriate, and when to focus on speed.

Adapting to the Times: Combining Microlearning Videos and Twitter to Teach Surgical Technique

OBJECTIVE

Surgical videos are commonly utilized by trainees to prepare for surgical cases. However, currently available videos tend to be of excessive length, variable quality, and exist behind paywalls or in other exclusive formats. Our objective was to create a series of videos that would address these shortcomings, and further allow for dynamic engagement between learners and experts.

DESIGN

Our group created surgical videos using principles of microlearning, an educational strategy which deconstructs content into small units and uses social media platforms where learners and educators may actively engage. We published a library of short (<3 min) videos covering various steps of abdominal transplantation operations on a YouTube channel. We leveraged Twitter to disseminate the content and engage with experts and learners from around the world.

SETTING

Multi-institutional.

RESULTS

Over the period from July 2020 to January 2021, 24 microlearning videos were created, stored on a YouTube channel, and posted to Twitter weekly using a newly created account. During that time period, the videos, averaging 124 seconds in length, were viewed 4393 times and watched for a total of 127 hours. The account gained 611 followers in 37 countries and 37 US states with 312,400 impressions (defined as tweet views). Twitter users who engaged with our microlearning content (favorite, retweet, or reply) included faculty (27%), residents (21%), fellows (8%), and medical students (11%).

CONCLUSIONS

Broad participation with the educational material and discussion on Twitter demonstrated the potential for the microlearning technique to provide educational benefit for learners internationally. The spread of the tweets shows an opportunity to augment traditional surgical education, and the willingness of faculty to discuss alternative techniques with their peers. Our group will continue to develop a library of microlearning videos for surgical operations and engage with other institutions for collaboration and expansion.

Graft Survival and Segment Discards Among Split-Liver and Reduced-Size Transplantations in the United States From 2008 to 2018

Split-liver transplantation has allocation advantages over reduced-size transplantation because of its ability to benefit 2 recipients. However, prioritization of split-liver transplantation relies on the following 3 major assumptions that have never been tested in the United States: similar long-term transplant recipient outcomes, lower incidence of segment discard among split-liver procurements, and discard of segments among reduced-size procurements that would be otherwise "transplantable." We used United Network for Organ Sharing Standard Transplant Analysis and Research data to identify all split-liver (n = 1831) and reduced-size (n = 578) transplantation episodes in the United States between 2008 and 2018. Multivariable Cox proportional hazards modeling was used to compare 7-year all-cause graft loss between cohorts. Secondary analyses included etiology of 30-day all-cause graft loss events as well as the incidence and anatomy of discarded segments. We found no difference in 7-year all-cause graft loss (adjusted hazard ratio [aHR], 1.1; 95% confidence interval [CI], 0.8-1.5) or 30-day all-cause graft loss (aHR, 1.1; 95% CI, 0.7-1.8) between split-liver and reduced-size cohorts. Vascular thrombosis was the most common etiology of 30-day all-cause graft loss for both cohorts (56.4% versus 61.8% of 30-day graft losses; P = 0.85). Finally, reduced-size transplantation was associated with a significantly higher incidence of segment discard (50.0% versus 8.7%) that were overwhelmingly right-sided liver segments (93.6% versus 30.3%). Our results support the prioritization of split-liver over reduced-size transplantation whenever technically feasible.

Non-English Language Resources and Readability of Kidney Transplant Center Websites in the United States

This study examined US kidney transplant center websites for readability and for inclusion of languages other than English.

Perioperative Risks of Sleeve Gastrectomy Versus Roux-en-Y Gastric Bypass Among Patients With Chronic Kidney Disease: A Review of the MBSAQIP Database

OBJECTIVE

To determine whether patients with CKD experience higher rates of perioperative complications after RYGB compared to sleeve gastrectomy.

SUMMARY OF BACKGROUND DATA

For obese CKD patients who qualify for bariatric surgery, sleeve gastrectomy is often preferred to RYGB based on perceptions of prohibitively-high perioperative risks surrounding RYGB. However, some patients with CKD are not candidates for sleeve gastrectomy and the incremental increased-risk from RYGB has never been rigorously tested in this population.

METHODS

CKD patients who underwent RYGB or sleeve gastrectomy between 2015 and 2017 were identified from the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program Participant Use File. RYGB patients were 1:1 propensity-score matched with sleeve gastrectomy patients based on preoperative factors that influence operative choice. Primary outcomes included 30-day readmissions, surgical complications, medical complications, and death. Secondary outcomes included the individual complications used to create the composite surgical/medical complications. Univariate logistic regression was used to compare outcomes. E-value statistic was used to test the strength of outcome point estimates against possible unmeasured confounding.

RESULTS

Demographics were similar between RYGB (n = 673) and sleeve gastrectomy (n = 673) cohorts. There were no statistically significant differences in primary outcomes. Among secondary outcomes, only acute kidney injury was statistically-significantly higher among RYGB patients (4.9% vs 2.7%, P = 0.035, E-value 1.27).

CONCLUSIONS

Among well-matched cohorts of RYGB and sleeve gastrectomy patients, incidence of primary outcomes were similar. Among secondary outcomes, only acute kidney injury was statistically-significantly higher among RYGB patients; however, the E-value for this difference was small and relatively weak confounder(s) could abrogate the statistical difference. The perception that RYGB has prohibitively-high perioperative risks among CKD patients is disputable and operative selection should be weighed on patient candidacy and anticipated long-term benefit.

Association of COVID-19 With New Waiting List Registrations and Liver Transplantation for Alcoholic Hepatitis in the United States

This cross-sectional study examines trends in new waiting list registrations and liver transplantation for alcoholic hepatitis before and during the COVID-19 pandemic in the US.

Associations Among Different Domains of Quality Among US Liver Transplant Programs

Importance

US liver transplant programs have traditionally been evaluated on 1-year patient and graft survival. However, there is concern that a narrow focus on recipient outcomes may not incentivize programs to improve in other ways that would benefit patients with end-stage liver disease.

Objective

To determine the correlation among different potential domains of quality for adult liver transplant programs.

Design, Setting, and Participants

This retrospective cohort study was conducted from 2014 to 2019 among adult liver transplant programs included in the United Network for Organ Sharing and Scientific Registry of Transplant Recipients program-specific reports. Liver transplant programs in the United States completing at least 10 liver transplants per year were included. Data were analyzed from March 2 to August 13, 2020.

Main Outcomes and Measures

The potential domains of quality examined included recipient outcomes (1-year graft and patient survival), aggressiveness (ie, marginal graft use, defined as the rate of use of donors with body mass index [calculated as weight in kilograms divided by height in meters squared] greater than 40, age older than 65 years, or deceased by cardiac death), and waiting list management (ie, waiting list mortality). The correlation among measures, aggregated at the center level, was evaluated using linear regression to control for mean Model for End Stage Liver Disease-Sodium score at organ allocation. The extent to which programs were able to achieve high quality across multiple domains was also evaluated.

Results

Among 114 transplant programs that performed a total of 44 554 transplants, the mean (SD) 1-year graft and patient survival was 90.3% (3.0%) with a total range of 75.9% to 96.6%. The mean (SD) waiting list mortality rate was 16.7 (6.1) deaths per 100 person-years, with a total range of 6.3 to 53.0 deaths per 100 person years. The mean (SD) marginal graft use rate was 15.8 (8.8) donors per 100 transplants, with a total range of 0 to 49.3 donors. There was no correlation between 1-year graft and patient survival and waiting list mortality (β = -0.053; P = .19) or marginal graft use (β = -0.007; P = .84) after correcting for mean allocation Model for End Stage Liver Disease-Sodium scores. There were 2 transplant programs (1.8%) that performed in the top quartile on all 3 measures, while 4 transplant programs (3.6%) performed in the bottom quartile on all 3 measures.

Conclusions and Relevance

This cohort study found that among US liver transplant programs, there were no correlations among 1-year recipient outcomes, measures of program aggressiveness, or waiting list management. These findings suggest that a program's performance in one domain may be independent and unrelated to its performance on others and that the understanding of factors contributing to these domains is incomplete.

Changes in Dialysis Center Quality Associated With the End-Stage Renal Disease Quality Incentive Program : An Observational Study With a Regression Discontinuity Design

BACKGROUND

In 2012, the Centers for Medicare & Medicaid Services started levying performance-based financial penalties against outpatient dialysis centers under the mandatory End-Stage Renal Disease Quality Incentive Program.

OBJECTIVE

To determine whether penalization was associated with improvement in dialysis center quality.

DESIGN

Leveraging the threshold for penalization (total performance score < 60), a regression discontinuity design was used to examine the effect of penalization on quality over 2 years. Publicly available Medicare data from 2015-2018 were used. The effect of penalization at dialysis centers with different characteristics (for example, size or chain affiliation) was also examined.

SETTING

United States.

PARTICIPANTS

Outpatient dialysis centers (n = 5830).

MEASUREMENTS

Dialysis center total performance scores (a composite metric ranging from 0 to 100 based on clinical quality and adherence to reporting requirements) and individual measures that contribute to the total performance score.

RESULTS

There were 1109 (19.0%) outpatient dialysis centers that received penalties in 2017 on the basis of performance in 2015. Penalized centers were located in ZIP codes with a higher average proportion of non-White residents (36.4% vs. 31.2%; P < 0.001) and residents with lower median income ($49 290 vs. $51 686; P < 0.001). Penalization was not associated with improvement in total performance scores in 2017 (0.4 point [95% CI, -2.5 to 3.2 points]) or 2018 (0.3 point [CI, -2.8 to 3.4 points]). This was consistent across dialysis centers with different characteristics. There was also no association between penalization and improvement in specific measures.

LIMITATION

The study could not account for how centers respond to penalization.

CONCLUSION

Penalization under the End-Stage Renal Disease Quality Incentive Program was not associated with improvement in the quality of outpatient dialysis centers.

PRIMARY FUNDING SOURCE

None.

Evaluation of an opioid restrictive pain management initiative in adult kidney transplant recipients

PURPOSE

Evidence to guide opioid utilization following kidney transplantation is lacking. The purpose of this study is to evaluate the implementation of an opioid restrictive post-operative pain management protocol in adult kidney transplant recipients.

METHODS

We analyzed patients who underwent kidney transplant between 1/1/2017 to 8/15/2018. A standardized, opioid restrictive pain management protocol was implemented in February 2018. The primary outcome was quantity of opioid tablets prescribed at discharge. Secondary outcomes included amount of opioid prescribed within first 30 days, number of patient calls for pain, and opioid prescription in electronic medical record (EMR) at 90 days and 1 year.

RESULTS

After implementation, significantly fewer opioid tablets were prescribed at discharge (4 vs. 60 tablets, p < .001) and less oral morphine milligram equivalence (OME) were prescribed within 30 days of transplant (38 vs. 300, p < .001). In cohort 2, fewer patients received more than one opioid prescription, more patients received truncal block and only 5 patients received patient controlled analgesia compared to all in cohort 1.

CONCLUSION

A standardized, patient-centered pain management strategy after kidney transplantation reduced opioid prescribing without increasing readmissions or clinic calls. This data may be used to inform guidelines for appropriate OME prescribing at discharge after kidney transplantation.

Bariatric Surgery and Long-term Survival in Patients With Obesity and End-stage Kidney Disease

Importance

Obesity rates in patients with end-stage kidney disease are rising, contribute to excess morbidity, and limit access to kidney transplant. Despite this, there continues to be controversy around the use of bariatric surgery in this patient population.

Objective

To determine whether bariatric surgery is associated with improvement in long-term survival among patients with obesity and end-stage kidney disease.

Design, Setting, and Participants

Retrospective cohort study and secondary analysis of previously collected data from the United States Renal Data System registry (2006-2015). We used Cox proportional hazards analysis to evaluate differences in outcomes for patients receiving bariatric surgery (n = 1597) compared with a matched cohort of nonsurgical patients (n = 4750) receiving usual care. Data were analyzed between September 3, 2019, and November 13, 2019.

Exposure

Receipt of bariatric surgery.

Main Outcomes and Measures

All-cause mortality at 5 years. Secondary outcomes included disease-specific mortality and incidence of kidney transplant.

Results

Surgical and nonsurgical control patients had similar age, demographics, and comorbid disease burden. The mean (SD) age was 49.8 (11.2) years for surgical patients vs 51.7 (11.1) years for nonsurgical patients. Six hundred fifteen surgical patients (38.5%) were black vs 1833 nonsurgical patients (38.6%). Surgery was associated with lower all-cause mortality at 5 years compared with usual care (cumulative incidence, 25.6% vs 39.8%; hazard ratio, 0.69, 95% CI, 0.60-0.78). This was driven by lower mortality from cardiovascular causes at 5 years for patients undergoing bariatric surgery compared with nonsurgical control patients (cumulative incidence, 8.4% vs 17.2%; hazard ratio, 0.51; 95% CI, 0.41-0.65). Bariatric surgery was also associated with an increase in kidney transplant at 5 years (cumulative incidence, 33.0% vs 20.4%; hazard ratio, 1.82; 95% CI, 1.58-2.09). However, at 1 year, bariatric surgery was associated with higher all-cause mortality compared with usual care (cumulative incidence, 8.6% vs 7.7%; hazard ratio, 1.45; 95% CI, 1.13-1.85).

Conclusions and Relevance

Among patients with obesity and end-stage kidney disease, bariatric surgery was associated with lower all-cause mortality compared with usual care. Bariatric surgery was also associated with an increase in kidney transplant. Bariatric surgery may warrant further consideration in the treatment of patients with obesity and end-stage kidney disease.

Fostering Passion and Skills in Surgical Research Across the Medical Education Continuum: The Transplant Research, Education, and Engagement Group

OBJECTIVE

We describe a multilevel, collaborative research group for trainees and faculty engaging in transplant surgery research within one institution.

DESIGN

Transplant Research, Education, and Engagement (TREE) was designed to develop trainees' research skills and foster enthusiasm in transplant surgery along the educational continuum. Our research model intentionally empowers junior researchers, including undergraduates and medical students, to assume active roles on a range of research projects and contribute new ideas within a welcoming research and learning environment.

SETTING

Section of Transplant Surgery, Department of Surgery, Michigan Medicine, Ann Arbor, Michigan.

PARTICIPANTS

Undergraduate premedical students, first through fourth year medical students, general surgery residents, transplant surgery fellows, and transplant surgery faculty.

RESULTS

TREE was founded in September 2019 and has grown to include over 30 active members who meet weekly and collaborate virtually on a range of research projects, many of which are led by students. Trainees can assume both mentee and mentor roles and build their research, presentation and writing skills while collaborating academically.

CONCLUSIONS

Our model has increased trainees' engagement in transplant research projects and fosters early enthusiasm for the field. This model can be feasibly replicated at other institutions and within other subspecialties.

Introduction to the Best-Case/Worst-Case Framework Within Transplantation Surgery to Improve Decision-Making for Increased Risk Donor Organ Offers

Public Health Service increased risk donor kidneys are discarded 50% more often than nonincreased risk donor kidneys despite equivalent patient and graft survival outcomes. Patient and provider biases as well as challenges in risk interpretation contribute to the underuse of increased risk donor organs. As the ultimate decision to accept or reject an increased risk donor organ results from the patient-provider conversation, there is an opportunity to improve this dialogue. This report introduces the best-case/worst-case communication guide for structuring high-stake conversations on increased risk kidney offers between transplant providers and their patients. Through best case/worst case, providers focus on eliciting patient values and long-term goals. The patient's unique context can then inform an individualized discussion of "best," "worst," and "most likely" outcomes and support the provider's ultimate recommendation. Transplant providers are encouraged to adopt this communication strategy to enhance shared decision-making and improve patient outcomes.

Perioperative risks of bariatric surgery among patients with and without history of solid organ transplant

Bariatric surgery is effective among patients with previous transplant in limited case series. However, the perioperative safety of bariatric surgery in this patient population is poorly understood. Therefore, we assessed the safety of bariatric surgery among previous-transplant patients using a database that captures >92% of all US bariatric procedures. All primary, laparoscopic sleeve gastrectomy and Roux-en-Y gastric bypass procedures between 2017 and 2018 were identified from the MBSAQIP dataset. Patients with previous transplant (n = 610) were compared with patients without previous transplant (n = 321 447). Primary outcomes were 30 day readmissions, surgical complications, medical complications, and death. Multivariable logistic regression with predictive margins was used to compare outcomes. Previous transplant patients experienced higher incidence of readmissions (8.0% vs 3.5%), surgical complications (5.0% vs 2.7%), and medical complications (4.3% vs 1.5%). There was no difference in incidence of death (0.2% vs 0.1%). Among individual complications, there no statistical differences in intraabdominal leak, unplanned reoperation, myocardial infarction, or infectious complications. Baseline estimated glomerular filtration rate was found to be a strong moderator of primary outcomes, with the highest risk of complications occurring at the lowest baseline estimated glomerular filtration rate. Given the many long-term benefits of bariatric surgery among patients with previous transplant, our findings should not preclude this patient population from operative consideration.

Three Dimensionally Printed Interactive Training Model for Kidney Transplantation

OBJECTIVE

The purpose of this study is to describe the development of a low-cost, reusable, interactive 3D-printed model to simulate vascular anastomoses in kidney transplantation.

DESIGN

We used a de-identified high-resolution abdominal and pelvic computed tomography scan and computer-aided design software to create a model to simulate vascular anastomoses in kidney transplantation. Surgical residents were asked to tie anastomoses and complete a survey regarding the effectiveness of the model.

SETTING

University of Michigan (Ann Arbor, Michigan)-academic, tertiary care center.

PARTICIPANTS

University of Michigan general, vascular, and cardiothoracic surgery residents participated in this study (n = 12).

RESULTS

After using the model, all 12 residents reported having a better understanding of how to set up and sew the renal artery and vein anastomoses. All 12 residents found the model to be an effective teaching tool.

CONCLUSIONS

Surgical trainees find this low-cost, reusable, interactive 3D-printed model to be an effective way to develop the technical skills necessary for vascular anastomoses in kidney transplantation.

Bariatric surgery for prospective living kidney donors with obesity?

The obesity epidemic has gripped the transplant community. With nearly 40% of adults in the United States being obese (BMI ≥30 kg/m² ) and 20% being morbidly obese (BMI ≥35 kg/m² ), the implications for both donors and recipients of solid organs continue to grow.¹ Nowhere is this more impactful than the candidacy of living kidney donors (LKDs). As increasing numbers of obese adults present for LKD consideration and evidence of inferior outcomes among obese LKDs grows, transplant surgeons will become progressively challenged by how to manage these patients in the clinic. Therefore, we offer this Personal Viewpoint to the transplant surgery community in order to review the current impact of obesity on living kidney donation, highlight what weight-loss interventions have already been attempted, and discuss the role that referral for weight-loss interventions including bariatric surgery might have going forward.

Trends in Bariatric Surgery Procedures among Patients with ESKD in the United States

BACKGROUND AND OBJECTIVES

Despite the potential for improving health status or increasing access to transplantation, national practice patterns for bariatric surgery in obese patients with ESKD are poorly understood. The purpose of this study was to describe current trends in surgical care for this population.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Using 100% Medicare data, we identified all beneficiaries undergoing bariatric surgery in the United States between 2006 and 2016. We evaluated longitudinal practice patterns using linear regression models. We also estimated risk-adjusted complications, readmissions, and length of stay using Poisson regression for patients with and without ESKD.

RESULTS

The number of patients with ESKD undergoing bariatric surgery increased ninefold between 2006 and 2016. The proportional use of sleeve gastrectomy increased from <1% in 2006 to 84% in 2016. For sleeve gastrectomy, complication rates were similar between patients with and without ESKD (3.4% versus 3.6%, respectively; difference, -0.3%; 95% confidence interval, -1.3% to 0.1%; P=0.57). However, patients with ESKD had more readmissions (8.6% versus 5.4%, respectively; difference, 3.2%; 95% confidence interval, 1.9% to 4.6%; P<0.001) and slightly longer hospitals stays (2.2 versus 1.9 days, respectively; difference, 0.3; 95% confidence interval, 0.1 to 0.4; P<0.001).

CONCLUSIONS

This study suggests that laparoscopic sleeve gastrectomy has replaced Roux-en-Y gastric bypass as the most common bariatric surgical procedure in patients with ESKD. The data also demonstrate a favorable complication profile in patients with sleeve gastrectomy.

The impact of intraoperative fluid management during laparoscopic donor nephrectomy on donor and recipient outcomes

BACKGROUND

Intraoperative fluid management during laparoscopic donor nephrectomy (LDN) may have a significant effect on donor and recipient outcomes. We sought to quantify variability in fluid management and investigate its impact on donor and recipient outcomes.

METHODS

A retrospective review of patients who underwent LDN from July 2011 to January 2016 with paired kidney recipients at a single center was performed. Patients were divided into tertiles of intraoperative fluid management (standard, high, and aggressive). Donor and recipient demographics, intraoperative data, and postoperative outcomes were analyzed.

RESULTS

Overall, 413 paired kidney donors and recipients were identified. Intraoperative fluid management (mL/h) was highly variable with no correlation to donor weight (kg) (R = 0.017). The aggressive fluid management group had significantly lower recipient creatinine levels on postoperative day 1. However, no significant differences were noted in creatinine levels out to 6 months between groups. No significant differences were noted in recipient postoperative complications, graft loss, and death. There was a significant increase (P < 0.01) in the number of total donor complications in the aggressive fluid management group.

CONCLUSIONS

Aggressive fluid management during LDN does not improve recipient outcomes and may worsen donor outcomes compared to standard fluid management.

A Video-Based Coaching Intervention to Improve Surgical Skill in Fourth-Year Medical Students

OBJECTIVE

For senior medical students pursuing careers in surgery, specific technical feedback is critical for developing foundational skills in preparation for residency. This pilot study seeks to assess the feasibility of a video-based coaching intervention to improve the suturing skills of fourth-year medical students.

DESIGN

Fourth-year medical students pursuing careers in surgery were randomized to intervention vs. control groups and completed 2 video recorded suture tasks. Students in the intervention group received a structured coaching session between consecutive suturing tasks, whereas students in the control group did not. Each coaching session consisted of a video review of the students' first suture task with a faculty member that provided directed feedback regarding technique. Following each suturing task, students were asked to self-assess their performance and provide feedback regarding the utility of the coaching session. All videos were deidentified and graded by independent faculty members for evaluation of suture technique.

SETTING

The University of Michigan Medical School in Ann Arbor, Michigan.

PARTICIPANTS

All fourth-year medical students pursuing careers in surgical specialties were contacted via e-mail for voluntary participation. In all, 16 students completed both baseline and follow up suture tasks.

RESULTS

All students who completed the coaching session would definitely recommend the session for other students. A total of 94% of the students strongly agreed that the exercise was a beneficial experience, and 75% strongly agreed that it improved their technical skills. Based on faculty grading, students in the intervention group demonstrated greater average improvements in bimanual dexterity compared to students in the control group; whereas students in the control group demonstrated greater average improvements in domains of efficiency and tissue handling compared to the intervention group. Based on student self-assessments, those in the intervention group had greater subjective improvements in all scored domains of bimanual dexterity, efficiency, tissue handling, and consistency compared to the control group. Subjective, free-response comments centered on themes of becoming more aware of hand movements when viewing their suturing from a new perspective, and the usefulness of the coaching advice.

CONCLUSIONS

This pilot study demonstrates the feasibility of a video-based coaching intervention for senior medical students. Students who participated in the coaching arm of the intervention noticed improvements in all domains of technical skill and noted that the experience was overwhelmingly positive. In summary, video-based review shows promise as an educational tool in medical education as a means to provide specific technical feedback.

Abdominal adiposity, body composition and survival after liver transplantation

BACKGROUND

Current measures of obesity do not accurately describe body composition. Using cross-sectional imaging, objective measures of musculature and adiposity are possible and may inform efforts to optimize liver transplantation outcomes.

METHODS

Abdominal visceral fat area and psoas muscle cross-sectional area were measured on CT scans for 348 liver transplant recipients. After controlling for donor and recipient characteristics, survival analysis was performed using Cox regression.

RESULTS

Visceral fat area was significantly associated with post-transplant mortality (p < 0.001; HR = 1.06 per 10 cm(2) , 95% CI: 1.04-1.09), as were positive hepatitis C status (p = 0.004; HR = 1.78, 95% CI: 1.21-2.61) and total psoas area (TPA) (p < 0.001; HR = 0.91 per cm(2) , 95% CI: 0.88-0.94). Among patients with smaller TPA, the patients with high visceral fat area had 71.8% one-yr survival compared to 81.8% for those with low visceral fat area (p = 0.15). At five yr, the smaller muscle patients with high visceral fat area had 36.9% survival compared to 58.2% for those with low visceral fat area (p = 0.023).

CONCLUSIONS

Abdominal adiposity is associated with survival after liver transplantation, especially in patients with small trunk muscle size. When coupled with trunk musculature, abdominal adiposity offers direct characterization of body composition that can aid preoperative risk evaluation and inform transplant decision-making.

Evaluating the Use of Twitter to Enhance the Educational Experience of a Medical School Surgery Clerkship

OBJECTIVE

Although it has been suggested that social-networking services such as Twitter could be used as a tool for medical education, few studies have evaluated its use in this setting. We sought to evaluate the use of Twitter as a novel educational tool in a medical school surgery clerkship. We hypothesized that Twitter can enhance the educational experience of clerkship students.

DESIGN

We performed a prospective observational study. We created a new Twitter account, and delivered approximately 3 tweets per day consisting of succinct, objective surgical facts. Students were administered pre- and postclerkship surveys, and aggregate test scores were obtained for participating students and historical controls.

SETTING

Required third-year medical school surgery clerkship at the University of Michigan large tertiary-care academic hospital.

PARTICIPANTS

Third-year medical students.

RESULTS

The survey response rate was 94%. Preclerkship surveys revealed that most (87%) students have smartphones, and are familiar with Twitter (80% have used before). Following completion of the clerkship, most students (73%) reported using the Twitter tool, and 20% used it frequently. Overall, 59% believed it positively influenced their educational experience and very few believed it had a negative influence (2%). However, many (53%) did not believe it influenced their clerkship engagement. Aggregate mean National Board of Medical Examiners Shelf Examination scores were not significantly different in an analysis of medical student classes completing the clerkship before or after the Twitter tool (p = 0.37).

CONCLUSIONS

Most of today's learners are familiar with social media, and own the technology necessary to implement novel educational tools in this platform. Applications such as Twitter can be facile educational tools to supplement and enhance the experience of students on a medical school clerkship.

Geographic variation in use of laparoscopic colectomy for colon cancer

PURPOSE

Emerging evidence supporting the use of laparoscopic colectomy in patients with cancer has led to dramatic increases in utilization. Though certain patient and hospital characteristics may be associated with the use of laparoscopy, the influence of geography is poorly understood.

METHODS

We used national Medicare claims data from 2009 and 2010 to examine geographic variation in utilization of laparoscopic colectomy for patients with colon cancer. Patients were assigned to hospital referral regions (HRRs) where they were treated. Multivariable logistic regression was used to generate age, sex, and race-adjusted rates of laparoscopic colectomy for each HRR. Patient quintiles of adjusted HRR utilization were used to evaluate differences in patient and hospital characteristics across low and high-utilizing HRRs.

RESULTS

A total of 93,786 patients underwent colon resections at 3,476 hospitals during the study period, of which 30,502 (32.5%) were performed laparoscopically. Differences in patient characteristics between the lowest and highest quintiles of HRR utilization were negligible, and there was no difference in the availability of laparoscopic technology. Yet adjusted rates of laparoscopic colectomy utilization varied from 0% to 66.8% across 306 HRRs in the United States.

CONCLUSION

There is wide geographic variation in the utilization of laparoscopic colectomy for Medicare patients with colon cancer, suggesting treatment location may substantially influence a patient's options for surgical approach. Future efforts to reduce variation will require increased dissemination of training techniques, novel opportunities for learning among surgeons, and enhanced educational resources for patients.

Morphometric age and mortality after liver transplant

IMPORTANCE

Morphometric assessment has emerged as a strong predictor of postoperative morbidity and mortality. However, a gap exists in translating this knowledge to bedside decision making. We introduced a novel measure of patient-centered surgical risk assessment: morphometric age.

OBJECTIVE

To investigate the relationship between morphometric age and posttransplant survival.

DATA SOURCES

Medical records of recipients of deceased-donor liver transplants (study population) and kidney donors/trauma patients (morphometric age control population).

STUDY SELECTION

A retrospective cohort study of 348 liver transplant patients and 3313 control patients. We assessed medical records for validated morphometric characteristics of aging (psoas area, psoas density, and abdominal aortic calcification). We created a model (stratified by sex) for a morphometric age equation, which we then calculated for the control population using multivariate linear regression modeling (covariates). These models were then applied to the study population to determine each patient's morphometric age.

DATA EXTRACTION AND SYNTHESIS

All analytic steps related to measuring morphometric characteristics were obtained via custom algorithms programmed into commercially available software. An independent observer confirmed all algorithm outputs. Trained assistants performed medical record review to obtain patient characteristics.

RESULTS

Cox proportional hazards regression model showed that morphometric age was a significant independent predictor of overall mortality (hazard ratio, 1.03 per morphometric year [95% CI, 1.02-1.04; P < .001]) after liver transplant. Chronologic age was not a significant covariate for survival (hazard ratio, 1.02 per year [95% CI, 0.99-1.04; P = .21]). Morphometric age stratified patients at high and low risk for mortality. For example, patients in the middle chronologic age tertile who jumped to the oldest morphometric tertile have worse outcomes than those who jumped to the youngest morphometric tertile (74.4% vs 93.2% survival at 1 year [P = .03]; 45.2% vs 75.0% at 5 years [P = .03]).

CONCLUSIONS AND RELEVANCE

Morphometric age correlated with mortality after liver transplant with better discrimination than chronologic age. Assigning a morphometric age to potential liver transplant recipients could improve prediction of postoperative mortality risk.

Cigarette smoking in living kidney donors: donor and recipient outcomes

BACKGROUND

Living kidney donor pools are expanding with the use of "medically complex" donors. Whether or not to include cigarette smokers as living kidney donors remains unclear. The aim of this study was to determine the relationship between donor smoking and recipient outcomes. We hypothesized that donor smoking would increase donor complications and decrease allograft and recipient survival over time.

METHODS

The charts of 602 living kidney donors and their recipients were retrospectively reviewed. Kaplan-Meier survival analysis and Cox modeling were used to assess the relationships between smoking and recipient and allograft survival.

RESULTS

No difference in postoperative complications was seen in smoking versus non-smoking donors. Donor smoking at time of evaluation did not significantly decrease allograft survival (HR = 1.19, p = 0.52), but recipient smoking at evaluation did reduce allograft survival (HR = 1.74, p = 0.05). Both donor and recipient smoking decreased recipient survival (HR = 1.93, p < 0.01 vs HR = 1.74, p = 0.048).

DISCUSSION

When controlled for donor and recipient factors, cigarette smoking by living kidney donors significantly reduced recipient survival. This datum suggests that careful attention to smoking history is an important clinical measure in which to counsel potential donors and recipients. Policy efforts to limit donors with a recent smoking history should be balanced with the overall shortage of appropriate kidney donors.