Proficiency Levels and Validity Evidence for Scoring Metrics for a Virtual Reality and Inanimate Robotic Surgery Simulation Curriculum.

OBJECTIVE: Our institution recently implemented a virtual reality (VR) skills curriculum for general surgery residents using the SimNow simulator. Based on a content alignment study, we revised the curriculum to include only 20 of 33 VR tasks and we added 3 previously validated inanimate tasks. The purpose of this study was to establish expert-derived proficiency levels for all tasks and to evaluate the validity of the scoring for the VR tasks. DESIGN: Two expert robotic surgeons performed 5 repetitions of each VR and inanimate task. The trimmed mean (lowest scoring attempt and outliers [>2 standard deviations] were eliminated) was defined as the expert level for each task. For the VR tasks, expert levels were compared to resident performance to evaluate validity. SETTING: This study was conducted at the University of Texas Southwestern Medical Center (Dallas, TX), a tertiary care academic teaching hospital. PARTICIPANTS: Two expert robotic surgeons participated in this study. The data from 42 residents (PGY2-4) who completed the original curriculum was used to represent novice performance. RESULTS: Comparison of expert levels and resident performance was statistically significant for 15 VR tasks (supporting validity) and approached significance (p = 0.06, 0.09) for 2 VR tasks; expert levels were designated as proficiency levels for these 17 tasks. Group comparisons were clearly not significant (p = 0.2-0.8) for 3 VR tasks; 2 of these 3 tasks were retained as introductory exercises (with 3 repetitions required) and 1 was excluded. For the 3 inanimate tasks, expert levels minus 2 standard deviations were designated as proficiency levels. CONCLUSIONS: This analysis generated validity evidence for 15 VR tasks and established expert-derived proficiency levels for 17 VR tasks and 3 inanimate tasks. Our proposed curriculum now consists of 19 VR and 3 inanimate tasks using the selected proficiency levels. We anticipate that this design will maximize curriculum efficiency and effectiveness.

Methemoglobin as a marker of acute anemic stress in cardiac surgery.

Biological evidence supports plasma methemoglobin as a biomarker for anemia-induced tissue hypoxia. In this translational planned substudy of the multinational randomized controlled transfusion thresholds in cardiac surgery (TRICS-III) trial, which included adults undergoing cardiac surgery requiring cardiopulmonary bypass with a moderate-to-high risk of death, we investigated the relationship between perioperative hemoglobin concentration (Hb) and methemoglobin; and evaluated its association with postoperative outcomes. The primary endpoint was a composite of death, myocardial infarction, stroke, and severe acute kidney injury at 28 days. We observe weak non-linear associations between decreasing Hb and increasing methemoglobin, which were strongest in magnitude at the post-surgical time point. Increased levels of post-surgical methemoglobin were associated with a trend toward an elevated risk for stroke and exploratory neurological outcomes. Our generalizable study demonstrates post-surgical methemoglobin may be a marker of anemia-induced organ injury/dysfunction, and may have utility for guiding personalized approaches to anemia management. Clinicaltrials.gov registration NCT02042898.

Defining the Price Tag of Complications Following Pancreatic Surgery: A US National Perspective.

INTRODUCTION: Pancreatic surgery tends to have a high rate of postoperative complications due to its complex nature, significantly increasing hospital costs. Our aim was to describe the true association between complications and hospital costs in a national cohort of US patients. METHODS: The National Inpatient Sample was used to conduct a retrospective analysis of elective pancreatic resections performed between 2004 and 2017, categorizing them based on whether patients experienced major complications (MaC), minor complications (MiC), or no complications (NC). Multivariable quantile regression was used to analyze how costs varied at different percentiles of the cost curve. RESULTS: Of 37,893 patients, 45.3%, 28.6%, and 26.1% experienced NC, MiC, and MaC, respectively. Factors associated with MaC were a Charlson Comorbidity Index of ≥4, prolonged length of stay, proximal pancreatectomy, older age, male sex, and surgery performed at hospitals with a small number of beds or at urban nonteaching hospitals (all P < 0.01). Multivariable quantile regression revealed significant variation in MiC and MaC across the cost curve. At the 50th percentile, MiC increased the cost by $3352 compared to NC while MaC almost doubled the cost of the surgery, increasing it by $20,215 (both P < 0.01). The association between complications and cost was even greater at the 95th percentile, increasing the cost by $10,162 and $108,793 for MiC and MaC, respectively (P < 0.01). CONCLUSIONS: MiC and MaC were significantly associated with increased hospital costs. Furthermore, the relationship between MaC and costs was especially apparent at higher percentiles of the cost curve.

Feasibility, effectiveness and transferability of a novel mastery-based virtual reality robotic training platform for general surgery residents.

BACKGROUND: The annual number of robotic surgical procedures is on the rise. Robotic surgery requires unique skills compared to other surgical approaches. Simulation allows basic robot skill acquisition and enhances patient safety. The purpose of this study was to evaluate the feasibility, effectiveness, and transferability of a mastery-based curriculum using a new virtual reality (VR) robotic simulator for surgery resident training. METHODS: Nineteen PGY2s and 22 PGY4s were enrolled. Residents completed a pretest and posttest consisting of five VR and three previously validated inanimate tasks. Training included practicing 33 VR tasks until a total score ≥ 90% ("mastery") was achieved using automated metrics (time, economy of motion). Inanimate performance was evaluated by two trained, blinded raters using video review metrics (time, errors, and modified OSATS). Outcomes were defined as: curriculum feasibility (completion rate, training time, repetitions), training effectiveness (pre/post training skill improvement), and skill transferability (skill transfer to validated inanimate drills). Wilcoxon signed-rank and Mann-Whitney U tests were used; median (IQR) reported. RESULTS: Thirty-four of 41 residents (83%) achieved mastery on all 33 VR tasks; median training time was 7 h (IQR: 5'26″-8'52″). Pretest vs. post-test performance improved (all p < 0.001) according to all VR and Inanimate metrics for both PGY2 and PGY4 residents. Significant pretest performance differences were observed between PGY2 and PGY4 residents for VR but not inanimate tasks; no PGY2 vs. PGY4 posttest performance differences were observed for both VR and inanimate tasks. CONCLUSION: This mastery-based VR curriculum was associated with a high completion rate and excellent feasibility. Significant performance improvements were noted for both the VR and inanimate tasks, supporting training effectiveness and skill transferability. Additional studies examining validity evidence may help further refine this curriculum.

Mitral valve repair in a patient with mitral regurgitation and osteogenesis imperfecta tarda.

We present the case of a 62-year-old female with a diagnosis of osteogenesis imperfecta and mitral valve regurgitation. The patient underwent a mitral valve repair without complications. We describe the case and our surgical technique.