Innovating medical education: Development of an affordable, 3-D printed knot-tying simulator.

BACKGROUND: Three-dimensional (3-D) printing offers an innovative option to produce clinical simulators because of its low production costs and widespread availability. We aimed to develop a low-cost, 3-D printed knot-tying simulator that overcomes the barriers students face in self-directed skills development. APPROACH: Medical students completing a procedural residency preparation course (PRPC) completed a pre-survey with Likert scales and multiple choice questions to assess their perceptions of and barriers to self-directed knot-tying practice. Subsequently, a 3-D printed knot-tying simulator, which contains a progression of knot-tying challenges and a designated video curriculum, was designed. After utilising the simulator in a 1-hour, faculty-guided knot-tying session, PRPC students assessed the educational utility and usability of the simulator via a post-survey. EVALUATION: The primary barriers students faced in engaging in self-directed knot-tying practice included limited accessibility to simulators and insufficient knowledge of knot-tying techniques. Many students (91.3%, n = 21) agreed that practicing with the simulator improved their knot-tying motor skills and was easy to use (100%, n = 23). Twenty-two (95.7%) students agreed that they would continue to use the simulator beyond the knot-tying session and PRPC. IMPLICATIONS: We demonstrate the educational utility and usability of a novel 3-D printed knot-tying simulator for medical education. Enabling students to engage in self-directed technical skills development is critical in developing surgical skills that can translate to clinical environments. Our simulator highlights the benefits of 3-D printers as an innovative, inexpensive option to improve the availability and accessibility to medical education tools.

Nodo-Tie: an innovative, 3-D printed simulator for surgical knot-tying skills development.

Introduction: Clinical simulators are an important resource for medical students seeking to improve their fundamental surgical skills. Three-dimensional (3-D) printing offers an innovative method to create simulators due to its low production costs and reliable printing fidelity. We aimed to validate a 3-D printed knot-tying simulator named Nodo-Tie. Methods: We designed a 3-D printed knot-tying simulator integrated with a series of knot-tying challenges and a designated video curriculum made accessible via a quick-response (QR) code. The Nodo-Tie, which costs less than $1 to print and assemble, was distributed to second-year medical students starting their surgical clerkship. Participants were asked to complete a survey gauging the simulator's usability and educational utility. The time between simulator distribution and survey completion was eight weeks. Results: Students perceived the Nodo-Tie as easy-to-use (4.6 ± 0.8) and agreed it increased both their motor skills (4.5 ± 0.9) and confidence (4.5 ± 0.8) for tying surgical knots in the clinical setting. Many students agreed the Nodo-Tie provided a stable, durable surface for knot-tying practice (83.7%, n = 41) and that they would continue to use it beyond their participation in the study period (91.7%, n = 44). Discussion: Medical students found this interactive, 3-D printed knot-tying simulator to be an effective tool to use for self-directed development of their knot-tying skills. Given the Nodo-Tie's low cost, students were able to keep the Nodo-Tie for use beyond the study period. This increases the opportunity for students to engage in the longitudinal practice necessary to master knot-tying as they progress through their medical education. Key messages: Clinical simulators provide proactive learners with reliable, stress-free environments to engage in self-directed surgical skills development. The Nodo-Tie, a 3-D printed simulator, serves as a cost-effective, interactive tool for medical students to develop their knot-tying abilities beyond the clinical setting.

The incidence and natural history of ascites after liver transplantation.

BACKGROUND: Ascites is common in cirrhosis but uncommon after liver transplant. We aimed to characterize the incidence, natural history, and current management strategies of post-transplant ascites. METHODS: We performed a retrospective cohort study of patients who underwent liver transplantation at 2 centers. We included patients who underwent deceased donor whole graft liver transplants between 2002 and 2019. Chart review identified patients with post-transplant ascites, requiring a paracentesis between 1 and 6-month post-transplants. Detailed chart review identified clinical and transplant characteristics, evaluation of ascites etiology, and treatments. RESULTS: Of 1591 patients who successfully underwent a first-time orthotopic liver transplant for chronic liver disease, 101 (6.3%) developed post-transplant ascites. Only 62% of these patients required large volume paracentesis for ascites before transplant. 36% of patients with post-transplant ascites had early allograft dysfunction. Most patients with post-transplant ascites (73%) required a paracentesis within 2 months of transplant, but 27% had delayed ascites onset. From 2002 to 2019, ascites studies were obtained less often, and hepatic vein pressure measurement was performed more often. Diuretics were the mainstay of treatment (58%). The use of albumin infusion and splenic artery embolization to treat post-transplant ascites increased over time. Larger pre-transplant spleen size was associated with a greater number of post-transplant paracenteses (r=0.32 and p=0.003). For patients who underwent splenic intervention, paracentesis frequency was significantly reduced (1.6-0.4 paracenteses/month, p=0.0001). The majority (72%) of patients had clinical resolution of their ascites at 6-month post-transplant. CONCLUSIONS: Persistent or recurrent ascites continues to be a clinical issue in the modern era of liver transplantation. Most had clinical resolution within 6 months, some requiring intervention.

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.

Left digit bias in selection and acceptance of deceased donor organs.

BACKGROUND: Organs suitable for donation are a scarce resource and maximizing the use of available organs is a priority. We aimed to determine whether there is a supply restricting left digit bias in organs offered and accepted for donors entering a new decade of age. METHODS: Potential deceased organ donors (n = 105,387) who had any organs offered for transplantation from 2010 to 2019 Organ Procurement and Transplantation Network data were analyzed. Donors were identified 1 year before and after a decade altering birthday. RESULTS: At age 70 there was a 5.4% decrease in the probability of any organ placement compared to 69 (95% CI 1.1-9.7). There was a decrease of 0.25 organs (95% CI 0.13-0.37) after age 70. CONCLUSIONS: There was a significant left digit bias in the acceptance of any organs for transplantation at ages 60 and 70 as well as in the acceptance of a kidney at age 70.

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.

Population-based Trends in Obesity and Kidney Transplantation Among Patients With End-stage Kidney Disease.

Obesity is a barrier to transplant, reducing access and leading to worse outcomes versus nonobese adults. Most transplant centers in the United States maintain body mass index (BMI) cutoffs to listing for kidney transplantation of 35 to 40 kg/m2. There is little contemporary data on the prevalence of obesity among patients with end-stage kidney disease (ESKD) despite its impact on clinical outcomes and healthcare expenditures. METHODS: We utilized data from the US Renal Data System from 2008 to 2016 to identify a prevalent cohort of 1 079 410 patients with ESKD. Linear regression determined trends in the proportion of patients within each category of BMI. We also evaluated geographic variation in rates of obesity and transplantation across the United States. RESULTS: Among the 1 079 410 ESKD patients, the largest cohort of patients were those with obesity (n = 423 270; 39.2%). There were 309 707 (28.7%) patients with an overweight BMI and 274 683 (25.4%) with a normal BMI. The proportion of patients with obesity increased significantly from 36.8% in 2008 to 40.2% in 2016 (trend 0.28; 95% confidence interval, 0.05-0.51). There was significant geographic variation by state with rates of obesity ranging from 32.3% to 45.4% and state transplant rates among those obese patients ranging from 22.5% to 46.8%. There is a weak correlation between states with increased rates of obese ESKD patients and states with an increased obesity transplant rate as indicated with r = 0.40 (P = 0.003). CONCLUSIONS: Beneficiaries with obesity are now the largest and fastest growing demographic among patients with ESKD in the United States.

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 (ß = -0.053; P = .19) or marginal graft use (ß = -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.