Cumulative sum learning curve for cordocentesis among maternal-fetal medicine fellows in a low-cost simulation model.

OBJECTIVE: To determine the individual learning curves for cordocentesis in a low-cost simulator for maternal-fetal medicine (MFM) fellows. METHODS: This observational, descriptive, educational, and prospective study was performed from July through November 2022. After an introductory course based on a standardized technique for cordocentesis, each second-year MFM fellow who accepted to participate in the study performed this procedure using a low-cost simulation model, and experienced operators supervised the cordocenteses. Learning curves were then created using cumulative sum analysis (CUSUM). RESULTS: Seven second-year MFM fellows with no previous experience in cordocentesis accepted to participate in the study. A total of 2676 procedures were assessed. On average, residents performed 382 ± 70 procedures. The mean number of procedures to achieve proficiency was 369 ± 70, the overall success rate was 84.16%, and the corresponding failure rate was 15.84%. At the end of the study, all fellows were considered competent in cordocentesis. One fellow required 466 attempts to achieve competency, performing a total of 478 procedures, but the resident with the fewest attempts to reach competency required 219 procedures, completing 232 procedures. Some of the most frequent reasons for failed attempts included not reaching the indicated point for vascular access (20.99%) and being unable to retrieve the sample (69.10%). CONCLUSION: CUSUM analysis to assess learning curves, in addition to using low-cost simulation models, helped to appraise individualized learning, allowing an objective demonstration of competency for cordocentesis among MFM fellows.

Learning curve for intracorporeal robotic Padua ileal bladder: 10-year functional assessment from a high-volume single-centre series.

OBJECTIVES: To assess the impact of the learning curve (LC) on perioperative and long-term functional outcomes of a consecutive single-centre series of robot-assisted radical cystectomy with Padua intracorporeal orthotopic neobladder. PATIENTS AND METHODS: Patients treated between 2013 and 2022 were included, with ≥1 year of follow-up. The entire cohort was divided in tertiles. Categorical and continuous variables were compared. Joinpoint regression analysis was used to identify significant changes over the decade in linear slope of the 1-year day- and night-time continence. Uni- and multivariable Cox regression analyses identified predictors of day- and night-time continence recovery. Day-time continence was defined as 'totally dry' (no pads), night-time continence as pad wetness ≤50 mL (one safety pad). RESULTS: Overall, 200 patients were included. The mean hospital stay (P = 0.002) and 30-day complications (P = 0.04) significantly reduced over time; the LC significantly impacted on Trifecta achievement (P < 0.001). The 1-year day- and night-time continence probabilities displayed a significant improving trend (day-time continence annual average percentage change [AAPC] 11.45%, P < 0.001; night-time continence AAPC 10.05%, P = 0.009). The LC was an independent predictor of day- (hazard ratio [HR] 1.008; P < 0.001) and night-time continence (HR 1.004; P = 0.03) over time. CONCLUSION: Patients at the beginning of the LC had significantly longer hospitalisations, more postoperative complications, and lower Trifecta rates. At the 10-year analyses, we observed a significant improving trend for both the 1-year day- and night-time continence probabilities, highlighting the crucial role of the LC. However, we are unable to assess the case volume needed to achieve a plateau in terms of day- and night-time continence rates.

Assessment of the Learning Curve for a Single-Use Disposable Duodenoscope.

BACKGROUND AND AIMS: In response to documented duodenoscope-related infectious outbreaks of multidrug-resistant organisms, the Food and Drug Administration has recommended a transition to duodenoscopes with innovative designs, including duodenoscopes with disposable components or fully disposable duodenoscopes. We aim to characterize the learning curve (LC) for a single-use disposable duodenoscope. METHODS: We performed a retrospective analysis of a prospectively collected database from 31 patients who underwent ERCP by a single, experienced operator using the EXALT Model D® (Boston Scientific, Marlborough) disposable duodenoscope at a single tertiary referral center. The LC for this device was described by the number of cases needed to achieve proficiency using cumulative sum (CUSUM) analysis. Number of attempts to cannulate and time to cannulate the desired duct were assessed as separate endpoints. The overall mean number of attempts and overall mean time to cannulation were used as the target values in the respective CUSUM analyses. Proficiency was defined as the number of procedures where an inflection point was reached in the CUSUM graph. This observation indicates improving operator performance as shown by a decrease in the number of attempts and shortening of cannulation time after the defined number of procedures. RESULTS: Overall, 31 patients underwent ERCP using the EXALT Model D disposable duodenoscope by a single experienced endoscopist. 6 (19%) patients had a native papilla and the majority of these procedures were classified as ASGE complexity level 2 or above. The procedure was completed using solely the disposable duodenoscope in 27 patients (87%), while a reusable duodenoscope was required for procedure completion in 4 patients (13%). The cross-overs were distributed evenly across the performance period. Procedure-related adverse events included: post-ERCP pancreatitis (3%), bleeding (3%) and no perforations. In the analyses of both endpoints, an inflection of the CUSUM curves is achieved at 10 cases, indicating sustained reduction of cannulation attempts and time to cannulation. CONCLUSION: Among experienced pancreaticobiliary endoscopists, approximately 10 ERCPs is the threshold whereby procedure-related factors including cannulation success and procedural time improves. Procedure-related adverse events are consistent with those expected with reusable duodenoscopes. The need to cross-over from single-use duodenoscope to reusable duodenoscope did not appear to be related to the learning curve, as they were evenly distributed across the study period. These results can be used to guide adoption of single-use duodenoscopes into clinical practice.

Predicting the onset of end-stage knee osteoarthritis over two- and five-years using machine learning.

OBJECTIVE: Identifying participants who will progress to advanced stage in knee osteoarthritis (KOA) trials remains a significant challenge. Current tools, relying on total knee replacements (TKR), fall short in reliability due to the extraneous factors influencing TKR decisions. Acknowledging these limitations, our study identifies a critical need for a more robust metric to assess severe KOA. The end-stage KOA (esKOA) measure, which combines symptomatic and radiographic criteria, serves as a solid indicator. To enhance future trials that use esKOA as an endpoint, our study focuses on developing and validating a machine-learning tool to identify individuals likely to develop esKOA within 2 to 5 years. DESIGN: Utilizing the Osteoarthritis Initiative (OAI) data, we trained models on 3,114 participants and validated them with 606 participants for the right knee, and similarly for the left knee, with external validation from the Multicentre Osteoarthritis Study (MOST) involving 1,602 participants. We aimed to predict esKOA onset at 2-to-2.5 years and 4-to-5 years, defining esKOA by severe radiographic KOA with moderate/severe symptoms or mild/moderate radiographic KOA with persistent/intense symptoms. Our analysis considered 51 candidate predictors, including demographics, clinical history, physical examination, and X-ray evaluations. An online tool predicting esKOA progression, based on models with ten and nine predictors for the right and left knees, respectively, was developed. RESULTS: External validation (MOST) for the right knee at 2.5 years yielded an Area Under Curve (AUC) of 0.847 (95 % CI 0.811 to 0.882), and at 5 years, 0.853 (95 % CI 0.823 to 0.881); for the left knee at 2.5 years, AUC was 0.824 (95 % CI 0.782 to 0.857), and at 5 years, 0.807 (95 % CI 0.768 to 0.843). Models with fewer predictors demonstrated comparable performance. The online tool is available at: https://eskoa.shinyapps.io/webapp/. CONCLUSION: Our study unveils a robust, externally validated machine learning tool proficient in predicting the onset of esKOA over the next 2 to 5 years. Our tool can lead to more efficient KOA trials.

Assessment of Quality Outcomes and the Learning Curve for Robot-Assisted Anatomical Lung Resections.

Background: To determine the perioperative quality assessment results and learning curves for robot-assisted anatomical lung resection. Methods: We analyzed the data of the initial 400 patients who underwent lobectomies or segmentectomies by 1 surgeon from January 2020 to November 2021. The learning curve was analyzed using cumulative sum analysis. Results: The surgical experience was divided into an initial phase (1st-40th procedures), a transition phase (41st-131st procedures), and a proficient phase (132nd procedure onward). The operative time showed a conspicuously continuous improvement over the 400 consecutive patients. After the 120th procedure, there were significant improvements in the rate of persistent air leakage (11.7% versus 3.9%; P = .003), chest tube duration (3.92 ± 1.91 versus 2.99 ± 1.31, P = .00), and postoperative hospital stay (6.22 ± 2.02 versus 4.93 ± 1.44, P = .00). Conclusions: In conclusion, 40 patients were necessary to pass the learning curve, and technical proficiency with favorable perioperative outcomes was achieved after 120-130 patients.

Assessment of Return to Sport After ACL Reconstruction With Soft Tissue Autograft in Adolescent Athletes: Quadriceps Versus Hamstring Tendon.

Background: Quadriceps tendon soft tissue autograft represents an increasingly popular graft option for anterior cruciate ligament reconstruction (ACLR), particularly for adolescents, some of whom have an open physis, precluding use of graft options with bone plugs. Purpose/Hypothesis: The purpose of this study was to quantify return-to-sport performance assessments in adolescents at 6 months after ACLR with all-soft tissue quadriceps tendon autograft (ACLR-Q) versus hamstring tendon autograft (ACLR-HS). It was hypothesized that ACLR-Q would be associated with improved hamstring strength and hamstring-to-quadriceps (HS:Q) ratios compared with ACLR-HS, albeit with decreased quadriceps strength. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Included were patients aged 12 to 19 years who underwent primary ACLR by a single surgeon and who completed a return-to-sport performance assessment between 5 and 9 months postoperatively. The performance assessment included manual muscle strength tests (hamstring, quadriceps, hip abductor and adductor), dynamic balance test (Y-balance), and functional hop tests (single hop, triple hop, crossover hop, 6-m timed hop). Data were converted to limb symmetry indices, and limb symmetry index deficits were compared between the ACLR-Q and ACLR-HS cohorts using the Student t test or Wilcoxon-Mann-Whitney test. Results: An initial cohort of 90 ACLR-Q patients was compared with 54 ACLR-HS patients, with no significant differences in patient characteristics. Differences in meniscal repair rates, however, prompted use of propensity score matching on age, sex, body mass index, meniscectomy, and meniscal repair to produce comparable subcohorts. The matching resulted in 67 ACLR-Q and 52 ACLR-HS patients. Hamstring strength deficits were significantly greater in ACLR-HS versus ACLR-Q patients (-40.5% vs -5.7%; P < .001). Quadriceps strength deficits were significantly greater in ACLR-Q versus ACLR-HS patients (-12.8% vs -0.4%; P < .001). ACLR-Q patients had a significantly greater HS:Q ratio on the operative knee (P < .001) and significantly higher Y-balance composite score deficits (-2.9% vs -0.4%; P = .01) than ACLR-HS patients. There were no significant differences in hop test performance between groups. Conclusion: Adolescent athletes who underwent ACLR-Q showed significantly greater quadriceps strength deficits but significantly smaller hamstring strength deficits than those who underwent ACLR-HS, leading to more favorable HS:Q ratios in ACLR-Q patients at 6 months postoperatively.

Assessment of a Real-world Learning Curve for the Endoscopic Resection of Gastric Gastrointestinal Stromal Tumors.

BACKGROUND: Endoscopic resection (ER) is a proven treatment for gastric gastrointestinal stromal tumors (gGISTs). We aimed to assess the learning curve (LC) associated with ER for gGISTs and identify determinants. METHODS: We conducted an analysis of 289 patients who underwent the ER of gGISTs by an experienced endoscopist. To characterize the LC, we employed cumulative sum analysis of the duration of surgery. The participants were divided into an early phase (cases 1-50) and a later phase (case 51-289), which were compared. Furthermore, we identified risk factors for the conversion from endoscopic to laparoscopic resection (LR). RESULTS: The durations of surgery and hospitalization were shorter, and there were fewer complications and fasting days in the later phase. The conversion rates to LR were 6.0% and 2.5% in the early and later phases, respectively. The tumor diameter (≥3.0 cm) and invasion beyond the muscularis propria were significant risk factors for conversion to LR (odds ratio 17.92, 95% confidence interval 2.66-120.87; and 58.03, 6.40-525.84; respectively). CONCLUSIONS: The LC for ER of gGISTs lasts for approximately 50 cases. In addition, tumors ≥3.0 cm in diameter and those that invade beyond the muscularis propria are more likely to require conversion to LR.

Finding the Right Solvent: A Novel Screening Protocol for Identifying Environmentally Friendly and Cost-Effective Options for Benzenesulfonamide.

This study investigated the solubility of benzenesulfonamide (BSA) as a model compound using experimental and computational methods. New experimental solubility data were collected in the solvents DMSO, DMF, 4FM, and their binary mixtures with water. The predictive model was constructed based on the best-performing regression models trained on available experimental data, and their hyperparameters were optimized using a newly developed Python code. To evaluate the models, a novel scoring function was formulated, considering not only the accuracy but also the bias-variance tradeoff through a learning curve analysis. An ensemble approach was adopted by selecting the top-performing regression models for test and validation subsets. The obtained model accurately back-calculated the experimental data and was used to predict the solubility of BSA in 2067 potential solvents. The analysis of the entire solvent space focused on the identification of solvents with high solubility, a low environmental impact, and affordability, leading to a refined list of potential candidates that meet all three requirements. The proposed procedure has general applicability and can significantly improve the quality and speed of experimental solvent screening.

Learning curve of trans-areola single-site endoscopic thyroidectomy in a high-volume center: A CUSUM-based assessment.

BACKGROUND: Limited attempts have been made in trans-areola single-site endoscopic thyroidectomy (TASSET) due to technical challenges and the lengthy time for proficiency. This study aimed to define the learning curve of TASSET and to describe improvements in operative performance over time. METHODS: Based on 222 consecutive TASSET procedures, the learning curve was established according to the operation time by using cumulative sum analysis (CUSUM). The end-point of learning curve was defined as the number of cases necessitated to reach the initial surgical proficiency stage. The demographic information, surgical and oncological outcomes, surgical stress, and postoperative complications were also analyzed. RESULTS: There were 70 cases of simple lobectomy for benign nodules and 152 cases of lobectomy with central neck dissection (CND) for malignancy. The mean operative time was 106.54 ± 38.07 min (range: 46-274 min). The learning curve identified two phases: the skill acquisition phase (Case 1-Case 41) and the proficiency phase (Case 42-Case 222). There were no significant differences in demographic information, drainage amount and duration, oncological outcomes, and postoperative complications between the two phases (p > 0.05). Both operation time and postoperative hospitalization decreased significantly in Phase 2 (154.63 ± 52.21 vs. 95.64 ± 22.96 min, p < 0.001; 4.12 ± 0.93 vs. 3.65 ± 0.63 days, p < 0.001). Additionally, the mean variations of surgical stress factors (C-reactive protein and erythrocyte sedimentation rate) decreased significantly as the phase progress. The case number required for proficiency phase in benign and malignant tumor were 18 and 33, respectively, and lymph node resection posed a significant impact on the endpoint of the learning curve (p < 0.001). Meanwhile, the size of nodule showed no significant impact (p = 0.622). For right-handed surgeons, 16 cases and 25 cases were required for technical competence in left-sided and right-sided lesions, respectively, and no significant difference reached (p = 0.266). CONCLUSIONS: TASSET has demonstrated safe and technically feasible with comparable oncological outcomes. Experience of 41 cases was required for surgical competence and proficiency. The initial learning stage could be more quickly adopted by high-volume thyroid surgeons with standardized procedures.

The Impact of Surgical Expertise on the Cost-Effectiveness of Stapes Surgery.

INTRODUCTION: Otosclerosis is the primary cause of conductive hearing loss with normal otoscopy. As the condition worsens, certain patients may develop a sensorineural component. Patients with successful surgeries may still need hearing aids, which creates a dilemma for health professionals as there are insufficient data to make informed decisions. This study investigated the influence of the surgeon's proficiency level, individual patient factors (e.g., age at the time of intervention and survival rates), and surgery costs on the cost-effectiveness of stapes surgery. METHODS: We performed a cost-effectiveness analysis using an adapted Markov model incorporating annual all-cause mortalities. In addition, we introduced sensitivity analyses to address the effects of surgical expertise on adults with bilateral conductive hearing loss due to otosclerosis. A model was developed based on a decision tree with treatment options and complication scenarios for otosclerosis patients undergoing stapes surgery or receiving hearing aids. Annual all-cause mortality was considered. A sensitivity analysis was performed assigned to different training levels ("experts" and "less experienced") to simulate the effects of surgical experience on the cost-effectiveness of surgical outcomes. Successful surgery was defined as closing of the air-bone gap to 10 dB or less. Based on published data, "experts" were simulated with a 93.7% success rate, and "less experienced" were manufactured with a 68.9% success rate. RESULTS: Stapes surgery provides improved quality of life (QoL) compared to hearing aids with lower cumulative costs up to 87 years of age in the case of "expert" surgeons and up to 78 years of age, when performed by "less experienced" surgeons. CONCLUSIONS: Primary stapes surgery is highly cost-effective and delivers improved QoL compared to hearing aids with lower cumulative costs. Additionally, undergoing stapes surgical training remains highly cost-effective.

A cost analysis of robotic vs. video-assisted thoracic surgery: The impact of the learning curve and the COVID-19 pandemic.

Introduction: Robot-assisted thoracoscopic surgery (RATS) is an alternative to video-assessed thoracoscopic surgery (VATS) for the treatment of lung cancer but concern exists regarding the high associated costs. The COVID-19 pandemic added further financial pressure to healthcare systems. This study investigated the impact of the learning curve on the cost-effectiveness of RATS lung resection and the financial impact of the COVID-19 pandemic on a RATS program. Methods: Patients undergoing RATS lung resection between January 2017 and December 2020 were prospectively followed. A matched cohort of VATS cases were analyzed in parallel. The first 100 and most recent 100 RATS cases performed at our institution were compared to assess the learning curve. Cases performed before and after March 2020 were compared to assess the impact of the COVID-19 pandemic. A comprehensive cost analysis of multiple theatre and postoperative data points was performed using Stata statistics package (v14.2). Results: 365 RATS cases were included. Median cost per procedure was £7,167 and theatre cost accounted for 70%. Major contributing factors to overall cost were operative time and postoperative length of stay. Cost per case was £640 less after passing the learning curve (p < 0.001) largely due to reduced operative time. Comparison of a post-learning curve RATS subgroup matched to 101 VATS cases revealed no significant difference in theatre costs between the two techniques. Overall cost of RATS lung resections performed before and during the COVID-19 pandemic were not significantly different. However, theatre costs were significantly cheaper (£620/case; p < 0.001) and postoperative costs were significantly more expensive (£1,221/case; p = 0.018) during the pandemic. Discussion: Passing the learning curve is associated with a significant reduction in the theatre costs associated with RATS lung resection and is comparable with the cost of VATS. This study may underestimate the true cost benefit of passing the learning curve due to the effect of the COVID-19 pandemic on theatre costs. The COVID-19 pandemic made RATS lung resection more expensive due to prolonged hospital stay and increased readmission rate. The present study offers some evidence that the initial increased costs associated with RATS lung resection may be gradually offset as a program progresses.

Assessment of the self-confidence of obstetrics & gynecology fellows to perform a postpartum hemostasis hysterectomy.

INTRODUCTION: Hemostasis Hysterectomy (HH) is a last resort surgical procedure performed in situations of uncontrolled post-partum hemorrhage in maternity wards. The chances of being confronted with this situation are scarce during residency, and the situation is not well suited for teaching. Nevertheless, every obstetrician-gynecologist can be confronted with this stressful situation, and should therefore possess the surgical competence required, regardless of his routine practice. The aim of the present study is to evaluate clinical exposure and self-awareness concerning HH amongst obstetrics and gynecology residents and fellows. MATERIEL AND METHODS: We performed a survey amongst French obstetrics and gynecology fellows. An anonymous survey was sent by email between December 1, 2020 to July 1, 2021. RESULTS: Half of the interrogated fellows had practiced (as operator) an HH during residency with a senior and only 22,6% in post-residency. During the last year of residency 70% of them had performed less than 10 scheduled hysterectomies as primary operator. The laparoscopic approach was the most frequently practiced. Very few hysterectomies were performed as primary operator. Fellows with a surgical or mixed activity (both gynecological surgery and obstetrical activity in current practice) felt significantly more capable of performing HH compared to those with exclusive obstetrical or reproductive medicine activity; respectively 60% vs 36%, p = 0.008; Odds Ratio: 2.629 (95% CI 1.2214; 5.8094). CONCLUSION: The number of scheduled hysterectomies or HH performed as primary operator is very low during residency or fellowship. It remains largely inferior to the number deemed necessary in previous publications about the learning curve for scheduled hysterectomy, which varies from 18 to 80 interventions. Nowadays, the increasing number of residents, added to the decrease of hemostasis hysterectomies through better management of post-partum hemorrhage, pushes towards the development of specific training, such as "damage control simulation".

Predicting total knee replacement at 2 and 5 years in osteoarthritis patients using machine learning.

Objectives: Knee osteoarthritis is a major cause of physical disability and reduced quality of life, with end-stage disease often treated by total knee replacement (TKR). We set out to develop and externally validate a machine learning model capable of predicting the need for a TKR in 2 and 5 years time using routinely collected health data. Design: A prospective study using datasets Osteoarthritis Initiative (OAI) and the Multicentre Osteoarthritis Study (MOST). OAI data were used to train the models while MOST data formed the external test set. The data were preprocessed using feature selection to curate 45 candidate features including demographics, medical history, imaging assessments, history of intervention and outcome. Setting: The study was conducted using two multicentre USA-based datasets of participants with or at high risk of knee OA. Participants: The study excluded participants with at least one existing TKR. OAI dataset included participants aged 45-79 years of which 3234 were used for training and 809 for internal testing, while MOST involved participants aged 50-79 and 2248 were used for external testing. Main outcome measures: The primary outcome of this study was prediction of TKR onset at 2 and 5 years. Performance was evaluated using area under the curve (AUC) and F1-score and key predictors identified. Results: For the best performing model (gradient boosting machine), the AUC at 2 years was 0.913 (95% CI 0.876 to 0.951), and at 5 years 0.873 (95% CI 0.839 to 0.907). Radiographic-derived features, questionnaire-based assessments alongside the patient's educational attainment were key predictors for these models. Conclusions: Our approach suggests that routinely collected patient data are sufficient to drive a predictive model with a clinically acceptable level of accuracy (AUC>0.7) and is the first such tool to be externally validated. This level of accuracy is higher than previously published models utilising MRI data, which is not routinely collected.

Attaining competency and proficiency in minimally invasive mitral valve repair: a learning curve assessment using cumulative sum analysis.

OBJECTIVE: To evaluate the learning curve of minimally invasive mitral valvuloplasty (MVP). BACKGROUND: Minimally invasive MVP is characterized by minimal trauma, minimal bleeding, and short postoperative recovery time. The learning curve of any new procedure needs to be evaluated for learning and replication. However, minimally invasive mitral valve technique is a wide-ranging concept, no further analysis of the outcomes and learning curve of minimally invasive Mitral valvuloplasty has been performed. METHODS: One hundred and fifty consecutive patients who underwent minimally invasive MVP alone without concurrent surgery were evaluated. Using cardiopulmonary bypass (CPB) time and aortic clamping (AC) time as evaluation variables, we visualized the learning curve for minimally invasive MVP using cumulative sum analysis. We also analyzed important postoperative variables such as postoperative drainage, duration of mechanical ventilation, ICU stay and postoperative hospital stay. RESULTS: The slope of the fitted curve was negative after 75 procedures, and the learning curve could be crossed after the completion of the 75th procedure when AC and CPB time were used as evaluation variables. And as the number of surgical cases increased, CPB, AC, postoperative drainage, duration of mechanical ventilation, ICU stay and postoperative hospital stay all showed different degrees of decrease. The incidence of postoperative adverse events is similar to conventional Mitral valvuloplasty. CONCLUSION: Compared to conventional MVP, minimally invasive MVP provides the same satisfactory surgical results and stabilization can be achieved gradually after completion of the 75th procedure.

Surgeon-conducted color Doppler ultrasound deep inferior epigastric artery perforator mapping: A cohort study and learning curve assessment.

BACKGROUND: Perforator mapping using diagnostic methods facilitates deep inferior epigastric perforator (DIEP) flap planning. Computed tomographic angiography (CTA) is a well-proven tool for perforator mapping. However, the benefits of color Doppler ultrasonography (CDU) are as follows: 1) CDU involves dynamic real-time examination and 2) does not use radiation. Comparing the accuracies of both methods in a cohort of patients, this study aimed to evaluate the learning curve of surgeon-conducted CDU perforator mapping. METHODS: Twenty patients undergoing DIEP flap breast reconstruction were enrolled in a cohort study. All patients underwent CTA perforator mapping preoperatively. XY coordinates of significant perforators were subtracted by a radiologist. A single surgeon (sonographer) with minimal experience with CDU performed CDU perforator mapping, including XY coordinates subtraction. The sonographer was blinded to the CTA data. The reference coordinates of dissected perforators were measured during surgery. Deviations from reference coordinates for both methods were compared, and CDU mapping learning curve was assessed using Joinpoint Regression. RESULTS: We included 20 women (32 DIEP flaps and 59 dissected perforators). The mean deviation between mapped and reference coordinates was 1.00 (0.50-1.12) cm for CDU and 0.71 (0.50-1.12) cm for CTA. The learning curve of CDU mapping showed the breaking point after the seventh patient (≈ 21 localized perforators). After the breaking point, no significant differences between the deviations of both methods were found (p = 0.980). CONCLUSION: A limited number of examinations were needed for the surgeon to learn CDU DIEA perforator mapping with accuracy similar to that of CTA mapping.

Improvement in Validity and Reliability of Airway Assessment Using Ultrasonography by Novice Personnel: A Learning Cohort Study.

Purpose: To assess improvements in the validity and reliability of novices' skills in performing ultrasonography for airway assessment. Patients and Methods: A learning cohort study was conducted with 20 anesthesiology residents and 10 volunteers in the Department of Anesthesiology, Faculty of Medicine, Prince of Songkla University. The four parameters of airway assessment were soft tissue thickness at the level of 1) hyoid bone (STT-HY), 2) true vocal cords (STT-VC), 3) thyroid isthmus (STT-TI), and 4) suprasternal notch (STT-SN). The magnitude of discrepancies between the residents' and experienced anesthesiologists' measurements was evaluated over the sequence of measurements in the 10 volunteers. Results: The mean ultrasonic measurements of STT-HY by the experienced anesthesiologists and residents were significantly different (11.09 ± 3.14 mm vs 8.53 ± 3.02 mm, respectively; P = 0.008), whereas measurements of STT-VC, STT-TI, and STT-SN were not (7.18 ± 1.70 vs 7.14 ± 1.93, P = 0.32; 7.81 ± 2.14 vs 7.73 ± 2.19, P = 0.62; and 11.32 ± 3.33 vs 10.30 ± 3.02, P = 0.35, respectively). The mean discrepancy between the residents' and experienced anesthesiologists' measurements was close to zero throughout the sequence of measurements of STT-TI and STT-VC. However, the residents' measurements of STT-HY and STT-SN were considerably lower than those of anesthesiologists. The range of discrepancies between residents and experienced anesthesiologists in each sequential measurement was wide for all measurements, particularly for the measurement values of STT-HY, and the standard deviation of the discrepancies did not decrease over the sequence of measurements. Conclusion: Over the sequence of measurements for airway assessment in 10 volunteers by 20 residents in this learning trial, we found no evidence of improvement in measurement accuracy. Discrepancies between the residents' and anesthesiologists' measurements and the variability in discrepancy across residents were greatest in the measurement of STT-HY.

Does pre-fellowship experience alter success rates of endoscopic treatment of vesicoureteral reflux during pediatric urology fellowship?

INTRODUCTION: Learning curve is a well-known factor that affects the success rate of endoscopic injection for vesicoureteral reflux (VUR). OBJECTIVE: To our knowledge, the significance of pre-fellowship training has not been studied. In the present study, our aim was to investigate the effect of pre-fellowship training on the endoscopic treatment success rates of pediatric urology fellows. DESIGN: A total of 78 patients aged 2-16 years (132 renal units) who underwent subureteric injection for the treatment of primary VUR by four pediatric urology fellows between 2014 and 2020 were retrospectively evaluated. Fellows were grouped into two as experienced and non-experienced according to the presence of pre-fellowship experience (defined as a minimum of 20 procedures). Patients in both groups were divided into two subgroups as non-dilating (grade I-II) and dilating VUR (grade III-V). Also, the change in success rate throughout the fellowship was analyzed. HIT or Double HIT method was used in all interventions. RESULTS: Experienced fellows carried out subureteric injection in 54 (40.9%) renal units while non-experienced fellows performed in 78 (59.1%). There was no success rate difference between experienced and non-experienced fellow groups in non-dilating VUR (100% vs. 88%, respectively p = 0.268), whereas the success rate of the experienced group was significantly higher in dilated VUR (78.9% vs. 50.9%, p = 0.006). Moreover, the amount of material used in the treatment of non-dilating VUR were similar between two fellow groups (0.6 ml vs. 0.6 ml, p = 0.500), while experienced group achieved higher success rates in dilating VUR by statistically significant less amount of injected volume (0.7 ml vs. 0.9 ml, p = 0.026).Overall complete VUR resolution rates were similar throughout the fellowship period in the experienced fellows (81.5% vs. 88.9%, p = 0.444), while it significantly increased in the non-experienced group implicating the completion of the learning curve (51.3% vs. 74.4%, p = 0.035). DISCUSSION: There has been no published reports on the effect of pre-fellowship experience on subureteric injection success. While many researchers reported on the importance of learning curve, various studies assessed the effect of injected volume on success rate implicating contradictory results. Furthermore, others indicated that the ideal technique providing accurate needle placement and obtaining proper depth during injection which is associated with surgical experience is more important than the injected volume in achieving success. CONCLUSION: Our results implicate that similar success rates in non-dilating VUR can be achieved regardless of previous subureteric injection training. However, higher failure rates may be expected when the procedures are performed by non-experienced pediatric urology fellows at the beginning of their fellowship in dilating VUR.

Development and evaluation of a virtual knowledge assessment tool for transanal total mesorectal excision.

BACKGROUND: Transanal total mesorectal excision (TATME) is difficult to learn and can result in serious complications. Current paradigms for assessing performance and competency may be insufficient. This study aims to develop and provide preliminary validity evidence for a TATME virtual assessment tool (TATME-VAT) to assess the cognitive skills necessary to safely complete TATME dissection. METHODS: Participants from North America, Europe, Japan and China completed the test via an interactive online platform between 11/2019 and 05/2020. They were grouped into expert, experienced and novice surgeons depending on the number of independently performed TATMEs. TATME-VAT is a 24-item web-based assessment evaluating advanced cognitive skills, designed according to a blueprint from consensus guidelines. Eight items were multiple choice questions. Sixteen items required making annotations on still frames of TATME videos (VCT) and were scored using a validated algorithm derived from experts' responses. Annotation (range 0-100), multiple choice (range 0-100), and overall scores (sum of annotation and multiple-choice scores, normalized to µ = 50 and σ = 10) were reported. RESULTS: There were significant differences between the expert, experienced, and novice groups for the annotation (p < 0.001), multiple-choice (p < 0.001), and overall scores (p < 0.001). The annotation (p = 0.439) and overall (p = 0.152) scores were similar between the experienced and novice groups. Annotation scores were higher in participants with 51 or more vs. 30-50 vs. less than 30 cases. Scores were also lower in users with a self-reported recent complication vs. those without. CONCLUSIONS: This study describes the development of an interactive video-based virtual assessment tool for TATME dissection and provides initial validity evidence for its use.

The learning curve in bladder MRI using VI-RADS assessment score during an interactive dedicated training program.

OBJECTIVE: The purpose of the study was to evaluate the effect of an interactive training program on the learning curve of radiology residents for bladder MRI interpretation using the VI-RADS score. METHODS: Three radiology residents with minimal experience in bladder MRI served as readers. They blindly evaluated 200 studies divided into 4 subsets of 50 cases over a 3-month period. After 2 months, the first subset was reassessed, resulting in a total of 250 evaluations. An interactive training program was provided and included educational lessons and case-based practice. The learning curve was constructed by plotting mean agreement as the ratio of correct evaluations per batch. Inter-reader agreement and diagnostic performance analysis were performed with kappa statistics and ROC analysis. RESULTS: As for the VI-RADS scoring agreement, the kappa differences between pre-training and post-training evaluation of the same group of cases were 0.555 to 0.852 for reader 1, 0.522 to 0.695 for reader 2, and 0.481 to 0.794 for reader 3. Using VI-RADS ≥ 3 as cut-off for muscle invasion, sensitivity ranged from 84 to 89% and specificity from 91 to 94%, while the AUCs from 0.89 (95% CI:0.84, 0.94) to 0.90 (95% CI:0.86, 0.95). Mean evaluation time decreased from 5.21 ± 1.12 to 3.52 ± 0.69 min in subsets 1 and 5. Mean grade of confidence improved from 3.31 ± 0.93 to 4.21 ± 0.69, in subsets 1 and 5. CONCLUSION: An interactive dedicated education program on bladder MRI and the VI-RADS score led to a significant increase in readers' diagnostic performance over time, with a general improvement observed after 100-150 cases. KEY POINTS: • After the first educational lesson and 100 cases were interpreted, the concordance on VI-RADS scoring between the residents and the experienced radiologist was significantly higher. • An increase in the grade of confidence was experienced after 100 cases. • We found a decrease in the evaluation time after 150 cases.

Assessment of the learning curve for the novel transanal minimally invasive surgery simulator model.

BACKGROUND: Transanal minimally invasive surgery (TAMIS) is technically demanding and requires extensive training. We developed the TAMIS simulator model by remodeling an existing laparoscopic training system to educate trainees and analyzed their learning curves. METHODS: Between March 2020 and June 2020, 12 trainees performed TAMIS simulator training sessions. The total operative time, including specimen removal and wound closure, was recorded. The wound closure and specimen quality, trainee self-confidence, and supervisor evaluation of technical performance were documented. A moving average was used to analyze the number of training sessions required to stabilize the procedure time, while a cumulative sum analysis was performed to identify that required to reach proficiency with each item. RESULTS: Each trainee completed 20 TAMIS simulator training sessions. The median total procedure time was 13 min (range, 4-60 min), which stabilized after 15 training sessions. The median times for specimen removal and wound closure were 3 min (range, 1-18 min) and 10 min (range, 2-50 min), respectively, which stabilized after 7 and 15 training sessions, respectively. The mean specimen and wound closure quality scores were 2.9 ± 0.9 (on a scale from 1 to 4) and 2.3 ± 1.1 (on a scale from 1 to 4), respectively, competencies in which were achieved after 16 and 20 training sessions, respectively. The mean trainee self-confidence and supervisor evaluation of technical performance scores were 2.4 ± 1.2 (on a scale from 1 to 5) and 2.7 ± 1.2 (on a scale from 1 to 5), respectively, competencies in which were achieved after 20 and 17 training sessions, respectively. CONCLUSION: Trainees required 15 training sessions to stabilize the procedure time and 16-20 training sessions to demonstrate competencies with the TAMIS simulator model. We expect this simulator model may help surgeons more rapidly acquire the skills required for TAMIS.