State of pediatric liver transplantation in the United States and achieving zero wait list mortality with ideal outcomes: A statement from the Starzl Network for Excellence in Pediatric Transplant Surgeon's Working Group.

BACKGROUND: Liver transplant is a life-saving therapy that can restore quality life for several pediatric liver diseases. However, it is not available to all children who need one. Expertise in medical and surgical management is heterogeneous, and allocation policies are not optimally serving children. Technical variant grafts from both living and deceased donors are underutilized. METHODS: Several national efforts in pediatric liver transplant to improve access to and outcomes from liver transplant for children have been instituted and include adjustments to allocation policies, UNOS-sponsored collaborative improvement projects, and the emergence of national learning networks to study ongoing challenges in the field the Surgical Working group of the Starzl Network for Excellence in Pediatric Transplantation (SNEPT) discusses key issues and proposes potential solutions to eliminate the persistent wait list mortality that pediatric patients face. RESULTS: A discussion of the factors impacting pediatric patients' access to liver transplant is undertaken, along with a proposal of several measures to ensure equitable access to life-saving liver transplant. CONCLUSIONS: Pediatric liver transplant wait list mortality can and should be eliminated. Several measures, including collaborative efforts among centers, could be leveraged to acheive this goal.

An overview of pediatric peritoneal dialysis and renal replacement therapy in infants: A review for the general pediatric surgeon.

Currently, there are about 10,000 pediatric patients in the United States who rely on dialysis for renal replacement therapy. Dialysis allows children with chronic kidney disease a means of support until renal transplant is feasible. All forms of renal replacement therapy require a surgical intervention, whether the modality is hemodialysis or peritoneal dialysis. Despite peritoneal dialysis being the most common modality of dialysis in children, there is not prospectively collected much evidence in the literature which can guide the pediatric surgeon about best practices on access placement, management of complications, and timing of removal. Most available studies are small, single-center retrospective reviews. This limits the power of the data collected to help guide decision-making in the management of peritoneal dialysis catheters. The purpose of this review is to provide a consolidated source of best available evidence and identify important areas for future study. Furthermore, this is an area of pediatric surgical care that lacks up to date outcomes research with robust surgeon participation. Lack of coordinated, evidence-based best practices likely results in heterogenous surgical practices and uneven strategies for managing complications. Furthermore, with improvements in neonatal critical care and fetal interventions available for obstructive uropathies and other congenital kidney disorders, there is increased likelihood of the need for dialysis access in more infants, who represent a particularly vulnerable patient population. Importantly, peritoneal dialysis access should be instituted into the national PEDScore curriculum for pediatric surgical fellows, as this procedure is common enough that any pediatric surgeon could be consulted for catheter placement and management. Surgeon awareness of, and participation in the formulation, of guidelines and prospective studies is of paramount importance to ensure optimal care of this vulnerable population of children.

Clinical regression of inguinal hernias in premature infants without surgical repair.

BACKGROUND: The incidence of inguinal hernias in premature infants is approximately 30%. Due to concerns about a high risk of incarceration, early repair is commonly performed. We present a series of patients whose families opted to delay repair until after 55 weeks corrected gestational age (GA) and experienced safe clinical regression of their hernias. METHODS: Between June 2015 and July 2020, premature infants (< 37 weeks GA) diagnosed with inguinal hernias on physical examination were identified. Families of eligible infants were offered either immediate or delayed repair after 55 weeks corrected GA. Infants whose families elected to delay were followed until their hernia(s) clinically regressed, or until older than 55 weeks. RESULTS: Families of 68 infants consented to delay repair. 23 infants (33.8%) had hernias that clinically regressed at median follow up from diagnosis of 14.1 weeks. Univariate analysis demonstrated female sex as a significant predictor of hernia clinical regression (OR: 3.08; p = 0.046). Of the 45 infants who underwent repair, 84.4% safely progressed to 55 weeks corrected GA prior to. CONCLUSION: Delaying inguinal hernia repair in this series of premature infants until after 55 weeks corrected GA revealed that one third of hernias, especially in females, safely regressed upon follow-up examination.

Upregulation of human endogenous retrovirus-K (HML-2) mRNAs in hepatoblastoma: Identification of potential new immunotherapeutic targets and biomarkers.

PURPOSE: Hepatoblastoma is the most common liver malignancy in children. In order to advance therapy against hepatoblastoma, novel immunologic targets and biomarkers are needed. Our purpose in this investigation is to examine hepatoblastoma transcriptomes for the expression of a class of genomic elements known as Human Endogenous Retrovirus (HERVs). HERVs are abundant in the human genome and are biologically active elements that have been associated with multiple malignancies and proposed as immunologic targets in a subset of tumors. A sub-family of HERVs, HERV-K(HML-2) (HERV-K), have been shown to be tightly regulated in fetal development, making investigation of these elements in pediatric tumors paramount. METHODS: We first created a HERVK-FASTA file utilizing 91 previously described HML-2 proviruses. We then concatenated the file onto the GRCh38.95 cDNA library from Ensembl. We used this reference database to evaluate existing RNA-seq data from 10 hepatoblastoma tumors and 3 normal liver controls (GEO accession ID: GSE8977575). Quantification and differential proviral expression analysis between hepatoblastoma and normal liver controls was performed using the pseudo-alignment program Salmon and DESeq2, respectively. RESULTS: HERV-K mRNA was expressed in hepatoblastoma from multiple proviral loci. All expressed HERV-K proviral loci were upregulated in hepatoblastoma compared to normal liver controls. Five HERV-K proviruses (1q21.3, 3q27.2, 7q22.2, 12q24.33 and 17p13.1) were significantly differentially expressed (p-adjusted value <0.05, |log2 fold change| > 1.5) across conditions. The provirus at 17p13.1 had an approximately 300-fold increased expression in hepatoblastoma as compared to normal liver. This was in part due to the near absence of HERV-K mRNA at the 17p13.1 locus in fully differentiated liver samples. CONCLUSIONS: Our investigation demonstrates that HERV-K is expressed from multiple loci in hepatoblastoma and that the expression is increased for several proviruses compared to normal liver controls. Our results suggest that HERV-K mRNA expression may be useful as a biomarker in hepatoblastoma, given the large differential expression profiles in hepatoblastoma, with very low mRNA levels in liver control samples.

A Quality Improvement Intervention to Reduce Postoperative Opiate Use in Neonates.

BACKGROUND AND OBJECTIVES: Opiate use in neonates can affect clinical outcomes after surgery and may alter future neurodevelopment. We implemented a multimodal opioid reduction strategy in our NICU for infants undergoing nonemergent gastrointestinal surgery. METHODS: After multiple stakeholder's meetings, our opioid reduction intervention included giving neonates postoperative standing intravenous acetaminophen every 6 hours for 48 hours, a standardized postsurgical sign-out with the NICU team in which pain control was directly addressed, and a series of postsurgical pain education seminars with NICU providers. To assess the impact of our quality improvement project, we used process control charts to investigate trends in postoperative opioid use in our preintervention (January 2012 to April 2016) and postintervention (May 2016 to September 2019) cohorts. RESULTS: A total of 77 infants were included in the study (40 in the preintervention cohort and 37 in the postintervention cohort). Patient characteristics were equivalent. The intervention significantly reduced the trend in postoperative morphine equivalents (median: 7.96 mg/kg in preintervention cohort versus 0.095 mg/kg in postintervention cohort; P < .0001). The Neonatal Pain, Agitation, and Sedation Scale pain scores and safety profiles were equivalent in both groups. The intervention was also associated with a 24-hour reduction in postoperative ventilation time (P < .048) and a 7-day reduction in the use of total parenteral nutrition (P < .017). CONCLUSIONS: Standing intravenous acetaminophen coupled with provider education can successfully reduce opioid use in postsurgical neonates. Given the concern for opioid exposure in neonatal neurodevelopment as well as clinical benefits of reduced opioids, similar strategies for opioid reduction may prove useful at other institutions.

Human endogenous retrovirus-K mRNA expression and genomic alignment data in hepatoblastoma.

Human Endogenous Retroviruses are a class of genomic elements that are the result of ancient retroviral infection of the human germline. Many are biologically active elements that have been implicated in multiple diseases including cancer. The most recent class to invade the human genome is the HERV-K(HML-2) (HERV-K) family. Approximately 90 HERV-K proviruses and many smaller elements have been identified to date in the human genome. Additional proviruses are continually being discovered with the rapid advancement of deep-sequencing and long-read sequencing technologies. HERV-K proviruses are poorly annotated in human transcriptome databases making their analysis in RNA-seq data difficult. To enable analysis, we compiled the sequences of 91 HERV-K proviruses identified in NCBI GenBank (ID JN675007-JN675097) and created a proviral alignment tool for visualizing RNA-seq reads aligned across individual proviruses. This allowed us to analyse publicly available RNA-seq data from 10 hepatoblastoma samples and 3 normal liver controls (GEO Accession ID: GSE89775). This data report includes the raw FASTA sequence files of the HERV-K proviruses from NCBI, a differential gene expression list between hepatoblastoma samples, and genomic alignment figures from 5 HERV-K proviruses identified as differentially expressed in the companion research article "Upregulation of Human Endogenous Retrovirus-K (HML-2) mRNAs in hepatoblastoma: Identification of potential new immunotherapeutic targets and biomarkers [1]. The data provided here are available for other research groups interested in evaluating individual HERV-K proviral expression using RNA-seq data. Furthermore, the data analysis is highly flexible and will accommodate the addition of other HERV-K proviruses.

Close to the Bedside: A Systematic Review of Endogenous Retroviruses and Their Impact in Oncology.

BACKGROUND: Human endogenous retroviruses (HERVs) are genetic elements in the human genome, which resulted from ancient retroviral germline infections. HERVs have strong transcriptional promoters and enhancers that affect a cell's transcriptome. They also encode proteins that can exert effects in human cells. This review examines how our increased understanding of HERVs have led to their potential use as biomarkers and immunologic targets. MATERIAL AND METHODS: PubMed/Medline, Embase, Web of Science, and Cochrane databases were used in a systematic search to identify all articles studying the potential impact of HERVs on surgical diseases. The search included studies that involved clinical patient samples in diseases including cancer, inflammatory conditions, and autoimmune disease. Articles focused on conditions not routinely managed by surgeons were excluded. RESULTS: Eighty six articles met inclusion and quality criteria for this review and were included. Breast cancer and melanoma have robust evidence regarding the use of HERVs as potential tumor markers and immunologic targets. Reported evidence of the activity of HERVs in colorectal cancer, pancreatic cancer, hepatocellular cancer, prostate and ovarian cancer, germ cell tumors as well as idiopathic pulmonary hypertension, and the inflammatory response in burns was also reviewed. CONCLUSIONS: Increasingly convincing evidence indicates that HERVs may play a role in solid organ malignancy and present important biomarkers or immunologic targets in multiple cancers. Innovative investigation of HERVs is a valuable focus of translational research and can deepen our understanding of cellular physiology and the effects of endogenous retroviruses on human biology. As strategies for treatment continue to focus on genome-based interventions, understanding the impact of endogenous retroviruses on human disease will be critical.

A novel retroviral vector system to analyze expression from mRNA with retained introns using fluorescent proteins and flow cytometry.

The ability to overcome cellular restrictions that exist for the export and translation of mRNAs with retained introns is a requirement for the replication of retroviruses and also for the expression of many mRNA isoforms transcribed from cellular genes. In some cases, RNA structures have been identified in the mRNA that directly interact with cellular factors to promote the export and expression of isoforms with retained introns. In other cases, a viral protein is also required to act as an adapter. In this report we describe a novel vector system that allows measurement of the ability of cis- and trans-acting factors to promote the export and translation of mRNAs with retained introns. One reporter vector used in this system is derived from an HIV proviral clone engineered to express two different fluorescent proteins from spliced and unspliced transcripts. The ratio of fluorescent signals is a measurement of the efficiency of export and translation. A second vector utilizes a third fluorescent protein to measure the expression of viral export proteins that interact with some of the export elements. Both vectors can be packaged into viral particles and be used to transduce cells, allowing expression at physiological levels from the integrated vector.

Sutureless closure: a versatile treatment for the diverse presentations of gastroschisis.

OBJECTIVE: Case series have demonstrated sutureless closures to be safe for the correction of gastroschisis. We hypothesize that sutureless closure is efficacious in patients requiring silo reduction without need for intubation. STUDY DESIGN: We conducted a retrospective case control study of infants who underwent gastroschisis repair at our institution (January 2011-August 2018). Patient characteristics and clinical outcomes were compared between sutureless closure and primary fascial repair groups. RESULTS: Seventeen patients in the sutureless group and 28 patients in the primary fascial repair group were included. Success of sutureless closure was 94%. Mechanical ventilation was reduced by 2.8 days in the sutureless group (P < 0.0001) and fewer patients required general anesthesia (29.4% vs. 100%, P < 0.0001). CONCLUSIONS: Sutureless closure is effective for the diverse presentations of gastroschisis. Given the concerns of effects of general anesthesia on the developing brain, sutureless closure should be strongly considered.

Long-Term Skills Retention Following a Randomized Prospective Trial on Adaptive Procedural Training.

OBJECTIVE: Cumulative sum (CuSum) is a real-time proficiency-monitoring tool adapted for simulation-based training. This study's objective was to investigate long-term outcomes of a double blinded, randomized control trial conducted with medical students assessing CuSum-guided curriculum against volume-based standards. The trial found a nearly 20% reduction in practice time to reach proficiency using the CuSum curriculum but long-term effects of decreased practice volume on proficiency is unknown. DESIGN: Prior participants completed a survey assessing confidence, exposure, and feedback at 12 to 18 months following trial completion. They underwent retention testing of suturing, intubation, and central venous catheter placement (CVC), which was video-recorded and assessed by an expert evaluator. Baseline characteristics among repeat subjects were compared using chi-squared tests. Retention and initial trial outcome were compared using paired parametric statistical methods. SETTING: The study was conducted at a major tertiary care center and training hospital. PARTICIPANTS: Medical students, which completed the initial randomized control trial were eligible for enrollment. A total of 30/46(65%) responded to the survey, whereas 33/46(72%) completed retention testing. RESULTS: Average scores and decay in procedural tasks over time for suturing, intubation and CVC were 91.6% (-4.7%), 86.1% (-4.1%), and 76.2% (-14.8%), respectively. Compared to the control group, the CuSum group mean difference in retention evaluation scores was -5.6% (p = 0.12). Confidence was not associated with initial or retention testing performance in any procedural task. Higher confidence was associated with additional exposure to the procedural task in suturing and intubation (p = 0.03 and p = 0.02, respectively). For intubation, higher confidence was reported by participants who received positive feedback (p = 0.01), and those assigned to the volume-based training arm (p = 0.03). CONCLUSION: CuSum-guided training was equivalent to conventional training for suturing, intubation, and CVC. These findings importantly suggest medical students can retain competency in invasive surgical tasks with modest decay in proficiency over time regardless of initial training method.

Laparoscopic Appendicostomy Low-Profile Balloon Button for Antegrade Enemas in Children.

INTRODUCTION: The Malone appendicostomy is a continent channel used for antegrade enemas. It requires daily cannulation and is susceptible to stenosis. We use an indwelling low-profile balloon button tube inserted through the appendix into the cecum for antegrade enemas. We hypothesized that this method is effective at managing constipation or fecal incontinence and is associated with a low rate of stenosis. METHODS: Children who underwent laparoscopic appendicostomy balloon button placement at our institution from January 2011 to April 2017 were identified. The primary outcome was success in managing constipation or fecal continence as measured by the Malone continence scale. Postoperative complications were analyzed. RESULTS: Thirty-six children underwent the procedure, 35 of which met the inclusion criteria. Thirty-one patients (88.5%) underwent the operation for idiopathic constipation, 3 patients (8.6%) for anorectal malformation, and 1 patient (2.9%) for hypermobility. Rate of open conversion was 3%. A full response was obtained in 24 patients (68.6%), partial response in 9 patients (25.7%), and 2 patients failed (5.7%). One patient developed an internal hernia requiring laparotomy and later developed mucosal prolapse. One patient developed a stricture noted at button change. Seven patients (20%) underwent reversal of their appendicostomy tube: 5 due to return of normal bowel function and 2 due to discomfort with flushes. CONCLUSION: A laparoscopic appendicostomy with a balloon button tube is an effective means of addressing chronic constipation or fecal incontinence. The stenosis rate associated with tube appendicostomy may be lower than those reported for Malone antegrade continence enema procedures.

Vessel Ligation Fundamentals: A Comparison of Technical Evaluations by Crowdsourced Nonclinical Personnel and Surgical Faculty.

BACKGROUND: Evaluation of fundamental surgical skills is invaluable to the training of medical students and junior residents. This study assessed the effectiveness of crowdsourcing nonmedical personnel to evaluate technical proficiency at simulated vessel ligation. STUDY DESIGN: Fifteen videos were captured of participants performing vessel ligation using a low-fidelity model (5 attending surgeons and 5 medical students before and after training). These videos were evaluated by nonmedical personnel recruited through Amazon Mechanical Turk, as well as by 3 experienced surgical faculty. Evaluation criteria were based on Objective Structured Assessment of Technical Skills (scale: 5-25). Results were compared using Wilcoxon signed rank-sum and Cronbach's alpha (α). RESULTS: Thirty-two crowd workers evaluated all 15 videos. Crowd workers scored attending surgeon videos significantly higher than pretraining medical student videos (20.5 vs 14.9, p < 0.001), demonstrating construct validity. Across all videos, crowd evaluations were more lenient than expert evaluations (19.1 vs 14.5, p < 0.001). However, average volunteer evaluations correlated more strongly with average expert evaluations (α = 0.95) than the strength of correlation between any 2 individual expert evaluators (α = 0.72-0.88). Combined reimbursement for all workers was $80.00. CONCLUSION: After adjustments for score inflation, crowdsourced can evaluate surgical fundamentals with excellent validity. This resource is considerably less costly and potentially more reliable than individual expert evaluations.

Predicting surgical skill acquisition in preclinical medical students.

BACKGROUND: The purpose of this study was to identify factors that predict medical student success in acquiring invasive procedural skills. We hypothesized that students with interest in surgery and with prior procedural experience would have higher rates of success. METHODS: Preclinical students were enrolled in a simulation course comprised of suturing, intubation, and central venous catheterization. Students completed surveys to describe demographics, specialty interest area, prior experience, and confidence. Using linear regression, variables predictive of proficiency were identified. RESULTS: Forty-five participants completed the course. Under univariate analysis, composite pretest score was inversely associated with confidence (P = .039). Under multivariable analysis, female gender was associated with higher pretest suturing score (P = .016). Male gender (P = .029) and high confidence (P = .021) were associated with greater improvement in suturing. CONCLUSIONS: Among novices, higher confidence can predict lower baseline technical proficiency. Although females had higher pretest suturing scores, high confidence and male gender were associated with the greatest degree of improvement.

Adaptive simulation training using cumulative sum: a randomized prospective trial.

BACKGROUND: Cumulative sum (Cusum) is a novel tool that can facilitate adaptive, individualized training curricula. The purpose of this study was to use Cusum to streamline simulation-based training. METHODS: Preclinical medical students were randomized to Cusum or control arms and practiced suturing, intubation, and central venous catheterization in simulation. Control participants practiced between 8 and 9 hours each. Cusum participants practiced until Cusum proficient in all tasks. Group comparisons of blinded post-test evaluations were performed using Wilcoxon rank sum. RESULTS: Forty-eight participants completed the study. Average post-test composite score was 92.1% for Cusum and 93.5% for control (P = .71). Cusum participants practiced 19% fewer hours than control group participants (7.12 vs 8.75 hours, P < .001). Cusum detected proficiency relapses during practice among 7 (29%) participants for suturing and 10 (40%) for intubation. CONCLUSIONS: In this comparison between adaptive and volume-based curricula in surgical training, Cusum promoted more efficient time utilization while maintaining excellent results.

Comparative effectiveness of catheter salvage strategies for pediatric catheter-related bloodstream infections.

BACKGROUND: Intravascular catheter salvage may be attempted in clinically suitable cases in pediatric patients with catheter-related bloodstream infections. The purpose of this study was to assess the effectiveness of ethanol and hydrochloric acid (HCl) locks in achieving catheter salvage through decision-analysis modeling. METHODS: A Markov decision model was created to simulate catheter salvage using three management strategies: systemic antibiotics alone, antibiotics plus HCl lock, and antibiotics plus ethanol lock. One-way and two-way sensitivity analyses were performed for all model variables. Infection control rates and recurrence rates for each strategy were derived from prospective institutional data and existing pediatric literature. Costs were derived from institutional charges. RESULTS: With antibiotics alone, 73% of patients would require line replacement within 100days, compared to only 31% and 19% of patients treated with HCl and ethanol lock, respectively. Incremental cost per additional catheter salvaged is $89 for HCl lock and $456 for ethanol lock. Superior efficacy of adjunct lock therapy is insensitive to changes in the anticipated duration of central access requirement and to clinically relevant variations in all model input variables. CONCLUSION: HCl or ethanol locks are cost-effective adjuncts to systemic antibiotics for attempted catheter salvage in the setting of catheter-related bloodstream infections.

Cumulative sum: An individualized proficiency metric for laparoscopic fundamentals.

BACKGROUND: A reliable metric of technical proficiency is indispensable to the training of fellows and residents. The purpose of this study was to determine whether cumulative sum (Cusum) has predictive validity in laparoscopic training. We hypothesized that Cusum would be a better predictor of technical ability in fundamentals of laparoscopic surgery (FLS) than traditional practice volume metrics. METHODS: Twenty medical students were recruited to practice three FLS tasks: peg transfer, circle cut, and intracorporeal knot tie. Up to 7hours of self-directed practice was allotted to each participant. Practice attempts were scored by standard FLS criteria and monitored via Cusum. Each participant's terminal Cusum performance was analyzed retrospectively. Posttests were conducted by faculty blinded to practice performance. RESULTS: Eighteen participants completed the study (90%). Median adjusted posttest scores were 102.3, 84.1, and 78.6 for peg transfer, circle cut, and knot tie, respectively. For the knot tie task, participants who exceeded the Cusum decision interval during their final practice attempts performed significantly higher on posttesting (81.2 vs 71.5, p=0.015). Knot tie terminal Cusum score was positively associated with posttest performance after adjusting for practice volume (p=0.031). Total practice volume and practice time were not significantly associated with posttest performance for any FLS task. CONCLUSION: Cusum score is a more valid representation of FLS proficiency than practice volume or practice time. Incorporating Cusum in a clinical setting may promote more efficient allocation of time resources and operative volume.

Chest radiography does not alter the treatment course for children after rigid bronchoscopy.

The purpose of this study was to evaluate the usefulness of chest radiography in the direction of postbronchoscopy clinical therapy. From 2001 to 2011, 368 rigid bronchoscopies were performed at a single institution in 221 children. Indications for bronchoscopy, concomitant bronchoscopic procedures, and results of postoperative chest radiography were evaluated. Rigid bronchoscopy was performed in children at a median age of 2.21 years (range, two days to 20 years). Chest radiography was performed at the discretion of the primary surgeon after 275 (74.7%) procedures. Malpositioning of the endotracheal or tracheostomy tube occurred in 1.5 per cent (n = three of 203) of ventilated patients postbronchoscopy. Pneumothorax occurred in 0.5 per cent (n = two of 368) of children and followed laser degranulation (n = one of 117 [0.9%]) and removal of an aspirated foreign body (n = one of 80 [1.3%]). Neither child required tube thoracostomy. Three children necessitated intraoperative tube thoracostomy placement for symptomatic pneumothoraces before radiographic assessment. No children sustained postprocedural complications in the absence of postbronchoscopy radiography. Postbronchoscopy chest radiography in the absence of defined symptomatology is not associated with a change in the postprocedural treatment course, suggesting selective application may be appropriate after at-risk bronchoscopic interventions. Such practice will limit the future cost and radiation exposure associated with this common procedure.

Vessel ligation training via an adaptive simulation curriculum.

BACKGROUND: A cost-effective model for open vessel ligation is currently lacking. We hypothesized that a novel, inexpensive vessel ligation simulator can efficiently impart transferrable surgical skills to novice trainees. MATERIALS AND METHODS: VesselBox was designed to simulate vessel ligation using surgical gloves as surrogate vessels. Fourth-year medical students performed ligations using VesselBox and were evaluated by surgical faculty using the Objective Structured Assessments of Technical Skills global rating scale and a task-specific checklist. Subsequently, each student was trained using VesselBox in an adaptive practice session guided by cumulative sum. Posttesting was performed on fresh human cadavers by evaluators blinded to pretest results. RESULTS: Sixteen students completed the study. VesselBox practice sessions averaged 21.8 min per participant (interquartile range 19.5-27.7). Blinded posttests demonstrated increased proficiency, as measured by both Objective Structured Assessments of Technical Skills (3.23 versus 2.29, P < 0.001) and checklist metrics (7.33 versus 4.83, P < 0.001). Median speed improved from 128.2 s to 97.5 s per vessel ligated (P = 0.001). After this adaptive training protocol, practice volume was not associated with posttest performance. CONCLUSIONS: VesselBox is a cost-effective, low-fidelity vessel ligation model suitable for graduating medical students and junior residents. Cumulative sum can facilitate an adaptive, individualized curriculum for simulation training.

Construct validation of a cost-effective vessel ligation benchtop simulator.

OBJECTIVE: Many benchtop surgical simulators assess laparoscopic proficiency, yet few address core open surgical skills. The purpose of this study is to describe a cost-effective benchtop vessel ligation simulator and provide construct validation. DESIGN: A prospective comparison of blinded proficiency assessments among participants performing a benchtop vessel ligation simulation task. Evaluations were performed using Objective Structured Assessments of Technical Skills. SETTING: This study took place at the University of Virginia, School of Medicine: a large academic medical institution. PARTICIPANTS: The participants included fourth-year medical students participating in a focused surgical elective course (n = 16), postgraduate year 2 to 3 surgery residents (n = 6), and surgical faculty (n = 5). RESULTS: The total fixed costs of the vessel ligation simulator was $30. Flexible costs of operation were less than $0.20 per attempt. The median task-specific checklist scores among the medical students, residents, and faculty were 4.83, 7.33, and 7.67, respectively. Median global rating scores across the 3 groups were 2.29, 4.43, and 4.76, respectively. Significant proficiency differences were noted between the students and the residents/faculty for both the metrics (p < 0.001). CONCLUSIONS: A cost-effective benchtop simulator can effectively measure proficiency with basic open surgical techniques such as vessel ligation. Among the junior surgical trainees, this tool can identify learning gaps and improve operative skills in a preclinical setting.

Assistant instructors facilitate simulation for medical students.

BACKGROUND: A procedural training protocol for medical students must be cognizant of faculty opportunity costs, which may preclude individually supervised practice. Meanwhile, sporadic exposure in large group settings yields suboptimal proficiency. The purpose of this study is to assess the effectiveness of undergraduate assistant instructors in providing one-on-one simulation-based instruction for basic invasive techniques. MATERIALS AND METHODS: Investigators designed proficiency-based checklists by faculty consensus for three simulation tasks as follows: orotracheal intubation, central venous catheterization, and suturing. Four undergraduate students were trained as instructors. Interrater agreement between instructors using the task checklists ranged from 0.754-0.866. Instructors conducted up to seven flexibly scheduled, one-on-one practice sessions with clinically inexperienced medical student participants. Sessions comprised repetitive task attempts with an evaluation after every attempt. On completion of the training protocol, participants underwent evaluation by an experienced surgeon blinded to practice session performance. Study participants were surveyed to assess satisfaction. RESULTS: Twenty-nine participants completed the study. Median total practice time was 8.75 h (interquartile range 7.12-8.75). Posttest pass rates were 93% (26/28), 71% (20/28), and 68% (19/28) for suturing, intubation, and central venous catheterization, respectively. Ninety-seven percent (27/28) of participants were satisfied with their experience, and 62% (18/29) advocated for protocol adoption into the standard preclinical curriculum. Estimated cost saved using student instructors, based on departmental collections for surgical faculty, was $43,760. CONCLUSIONS: Clinically inexperienced assistants may be trained as instructors for basic simulation tasks with excellent interrater reliability. Deploying these assistant instructors makes effective, one-on-one technical training for preclinical medical students financially feasible.