The Next Generation: Surgeon Learning Curve in a Mature Operative Rib Management Program.

INTRODUCTION: Prior work has demonstrated utility in using operative time to measure surgeon learning for surgical stabilization of rib fractures (SSRF); however, no studies have used operative time to evaluate the benefit of proctoring in subsequent generations of surgeons. We sought to evaluate whether there is a difference in learning between an original series (TOS) of self-taught surgeons versus the next generation (TNG) of proctored surgeons using cumulative summation (CUSUM) analysis. We hypothesized that TNG would have a comparatively accelerated learning curve. METHODS: A single-center retrospective review of all SSRF at a level 1 trauma center was performed. Data were collected from the beginning of an operative chest injury program to include at least 2 y of TNG experience. Operative time was used to determine success and misstep based on prior methods. Learning curves using CUSUM analysis were calculated based on an anticipated success rate of 90% and compared between TOS and TNG groups. RESULTS: Over 7 y, 163 patients with a median Injury Severity Score of 24 underwent SSRF. Median operative time was 165 min with a 0.5 plate-to-fracture ratio. All three TOS surgeons experienced a positive slope indicative of early missteps for their first 15-20 cases. By contrast, all three TNG surgeons demonstrated a series of early successes resulting in negative CUSUM slopes which coincided with a period of proctoring. By the end of TNG series, the composite cumulative score was less than half of the TOS surgeon' scores. CONCLUSIONS: Operative time continues to be a useful surrogate for observing SSRF learning curves. In a mature institutional program, proctored novice surgeons appear to have an accelerated learning curve compared to novice surgeons developing a new operative rib program.

Comparison of gasless transaxillary endoscopic thyroidectomy, endoscopic thyroidectomy via areola approach and conventional open thyroidectomy in patients with unilateral papillary thyroid carcinoma.

BACKGROUND: Gasless transaxillary endoscopic thyroidectomy (GTET) and endoscopic thyroidectomy via the areola approach (ETA) have emerged as minimally invasive surgical techniques for managing papillary thyroid carcinoma (PTC). This study aimed to assess the surgical efficacy of endoscopic thyroidectomy (ET) as compared to conventional open thyroidectomy (COT) in PTC patients. METHODS: Between 2020 and 2022, 571 PTC patients underwent unilateral thyroidectomy accompanied by ipsilateral central lymph node dissection. This cohort comprised 72 patients who underwent GTET, 105 ETA, and 394 COT. The analysis encompassed a comprehensive examination of patient clinicopathologic characteristics and postoperative complaints. Furthermore, the learning curve of GTET was evaluated using the cumulative summation (CUSUM) method. RESULTS: Patients in the ET group exhibited a lower mean age and a higher proportion of female individuals. Operation time in the ET group was significantly longer. No significant differences were observed in the incidence of postoperative complications among the three groups. With regard to postoperative complaints reported three months after surgery, GTET demonstrated superior alleviation of anterior chest discomfort and swallowing difficulties. Patients who underwent ET reported significantly higher cosmetic satisfaction levels. Additionally, the learning curve of GTET was 27 cases, and the operation time during the mature phase of the learning curve exhibited a significant reduction when compared to ETA. CONCLUSIONS: The findings of this study affirm the safety and feasibility of employing GTET and ETA for the surgical management of PTC. GTET presents an attractive surgical option, particularly for patients with unilateral PTC who place a premium on cosmetic outcomes.

Robotic intersphincteric resection for low rectal cancer: a cumulative sum analysis for the learning curve.

PURPOSE: This study aimed to assess the learning curve of robot-assisted intersphincteric resection for low rectal cancer. METHODS: We retrospectively analyzed the clinical data of 89 patients who underwent robot-assisted intersphincteric resection. All surgeries were performed by the same group of surgeons at our institution between June 2016 and April 2021. The learning curve was evaluated using a cumulative sum analysis and the best-fit curve. The different stages of the learning curve were compared based on patient characteristics and short-term clinical outcomes to evaluate their impact on clinical efficacy. RESULTS: The minimum number of cases required to overcome the learning curve was 47. The learning curve was divided into the learning improvement and proficiency stages. Significant differences were observed in the operation time and the number of lymph nodes between the two stages (P < 0.05), whereas no significant differences were found in intraoperative blood loss, first postoperative exhaust time, postoperative complications, 3-year progression-free survival, overall survival, and local recurrence-free survival (P > 0.05). CONCLUSION: Robotic-assisted intersphincteric resection for low rectal cancer exhibits a learning curve that can be divided into two stages: namely, learning improvement and proficiency. Achieving proficiency requires a minimum of 47 surgical cases.

Particle-Filter-Based Fault Diagnosis for the Startup Process of an Open-Cycle Liquid-Propellant Rocket Engine.

This study introduces a fault diagnosis algorithm based on particle filtering for open-cycle liquid-propellant rocket engines (LPREs). The algorithm serves as a model-based method for the startup process, accounting for more than 30% of engine failures. Similar to the previous fault detection and diagnosis (FDD) algorithm for the startup process, the algorithm in this study is composed of a nonlinear filter to generate residuals, a residual analysis, and a multiple-model (MM) approach to detect and diagnose faults from the residuals. In contrast to the previous study, this study makes use of the modified cumulative sum (CUSUM) algorithm, widely used in change-detection monitoring, and a particle filter (PF), which is theoretically the most accurate nonlinear filter. The algorithm is confirmed numerically using the CUSUM and MM methods. Subsequently, the FDD algorithm is compared with an algorithm from a previous study using a Monte Carlo simulation. Through a comparative analysis of algorithmic performance, this study demonstrates that the current PF-based FDD algorithm outperforms the algorithm based on other nonlinear filters.

CGR-CUSUM: a continuous time generalized rapid response cumulative sum chart.

Rapidly detecting problems in the quality of care is of utmost importance for the well-being of patients. Without proper inspection schemes, such problems can go undetected for years. Cumulative sum (CUSUM) charts have proven to be useful for quality control, yet available methodology for survival outcomes is limited. The few available continuous time inspection charts usually require the researcher to specify an expected increase in the failure rate in advance, thereby requiring prior knowledge about the problem at hand. Misspecifying parameters can lead to false positive alerts and large detection delays. To solve this problem, we take a more general approach to derive the new Continuous time Generalized Rapid response CUSUM (CGR-CUSUM) chart. We find an expression for the approximate average run length (average time to detection) and illustrate the possible gain in detection speed by using the CGR-CUSUM over other commonly used monitoring schemes on a real-life data set from the Dutch Arthroplasty Register as well as in simulation studies. Besides the inspection of medical procedures, the CGR-CUSUM can also be used for other real-time inspection schemes such as industrial production lines and quality control of services.

CUSUM learning curves: what they can and can't tell us.

INTRODUCTION: There has been increased interest in assessing the surgeon learning curve for new skill acquisition. While there is no consensus around the best methodology, one of the most frequently used learning curve assessments in the surgical literature is the cumulative sum curve (CUSUM) of operative time. To demonstrate the limitations of this methodology, we assessed the CUSUM of console time across cohorts of surgeons with differing case acquisition rates while varying the total number of cases used to calculate the CUSUM. METHODS: We compared the CUSUM curves of the average console times of surgeons who completed their first 20 robotic-assisted (RAS) cases in 13, 26, 39, and 52 weeks, respectively, for their first 50 and 100 cases, respectively. This analysis was performed for prostatectomy (1094 surgeons), malignant hysterectomy (737 surgeons), and inguinal hernia (1486 surgeons). RESULTS: In all procedures, the CUSUM curve of the cohort of surgeons who completed their first 20 procedures in 13 weeks demonstrated a lower slope than cohorts of surgeons with slower case acquisition rates. The case number at which the peak of the CUSUM curve occurs uniformly increases when the total number of cases used in generation of the CUSUM chart changes from 50 to 100 cases. CONCLUSION: The CUSUM analyses of these three procedures suggests that surgeons with fast initial case acquisition rates have less variability in their operative times over the course of their learning curve. The peak of the CUSUM curve, which is often used in surgical learning curve literature to denote "proficiency" is predictably influenced by the total number of procedures evaluated, suggesting that defining the peak as the point at which a surgeon has overcome the learning curve is subject to routine bias. The CUSUM peak, by itself, is an insufficient measure of "conquering the learning curve."

Resection speed of endoscopic submucosal dissection according to the location of gastric neoplasia: a learning curve using cumulative sum analysis.

BACKGROUND: There is few study evaluating the relationship between endoscopic submucosal dissection (ESD) resection speed and the lesion characteristics of gastric neoplasia. We investigated the learning curve of consecutive ESDs using cumulative sum (CUSUM) analysis. METHODS: A total of 356 ESDs performed by a single endoscopist were grouped chronologically into three learning periods. The ESD procedure was defined to be fast when resection speed was > 9.0 cm2/hour. The CUSUM method was used to assess the number of ESDs required for achieving proficiency and mastery. RESULTS: Mean resection speed was significantly faster in Phase III (15.1 cm2/hour) compared to those in Phase I (9.3 cm2/hour) and II (11.4 cm2/hour) (p < 0.001). Tumors in the stomach's upper and middle third location were significantly associated with difficulty in attaining the fast resection speed (odds ratios, 0.05 and 0.36) compared to the lower third location. The number of ESDs required to achieve a competency for fast resection was 15 for tumors in the lower third of the stomach and 98 for those in the upper/middle third location, respectively. In the lower third location of the tumor, the CUSUM curve revealed that 75 cases were needed to achieve proficiency and 174 cases to achieve mastery. However, mastery was not achieved in ESD for the upper/middle third tumor during the study period. CONCLUSION: The time required to achieve relevant competency in gastric ESD depends on the tumor location.

Learning curve of laparoscopic cholecystectomy: a risk-adjusted cumulative summation (RA-CUSUM) analysis of six general surgery residents.

BACKGROUND: Laparoscopic cholecystectomy (LapC) is one of the most frequently performed surgical procedures worldwide. Reaching technical competency in performing LapC is considered one essential task for young surgeons. Investigating the learning curve for LapC (LC-LapC) may provide important information regarding the learning process and guide the training pathway of residents, improving educational outcomes. The present study aimed to investigate LC-LapC among general surgery residents (GSRs). METHODS: Operative surgical reports of consecutive patients undergoing LapC performed by GSRs attending the General Surgery Residency Program at the University of Milan were analysed. Data on patient- and surgery-related variables were obtained from the ICD-9-CM diagnosis codes and gathered. A multidimensional assessment of the LC was performed through Cumulative Sum (CUSUM) and Risk-Adjusted (RA)-CUSUM analysis. RESULTS: 340 patients operated by 6 GSRs were collected. The CUSUM and RA-CUSUM graphs based on surgical failures allowed to distinguish two defined phases for all GSRs: an initial phase ending at the peak, so-called learning phase, followed by a phase in which there was a significant decrease in failure incidence, so-called proficiency phase. The learning phase was completed for all GSRs at most within 25 procedures, but the trend of the curves and the number of procedures needed to achieve technical competency varied among operators ranging between 7 and 25. CONCLUSIONS: The present study suggested that at most 25 procedures might be sufficient to acquire technical competency in LapC. The variability in the number of procedures needed to complete the LC, ranging between 7 and 25, could be due to the heterogeneous scenarios in which LapC was performed, and deserves to be investigated through a prospective study involving a larger number of GSRs and institutions.

Gasless laparoscopy in rural India-registry outcomes and evaluation of the learning curve.

BACKGROUND: A program of gasless laparoscopy (GL) has been implemented in rural North-East India. To facilitate safe adoption, participating rural surgeons underwent rigorous training prior to independent clinical practice. An online registry was established to capture clinical data on safety and efficacy and to evaluate initial learning curves for gasless laparoscopy. METHODS: Surgeons who had completed the GL training program participated in the online RedCap Registry. Patients included in the registry provided informed consent for the use of their data. Data on operative times, conversion rates, perioperative complications, length of stay, and hospital costs were collected. Fixed reference cumulative sum (CUSUM) model was used to evaluate the learning curve based on operative times and conversion rates published in the literature. RESULTS: Four surgeons from three rural hospitals in North-East India participated in the registry. The data were collected over 12 months, from September 2019 to August 2020. One hundred and twenty-three participants underwent GL procedures, including 109 females (88.6%) and 14 males. GL procedures included cholecystectomy, appendicectomy, tubal ligation, ovarian cystectomy, diagnostic laparoscopy, and adhesiolysis. The mean operative time was 75.3 (42.05) minutes for all the surgeries. Conversion from GL to open surgery occurred in 11.4% of participants, with 8.9% converted to conventional laparoscopy. The main reasons for conversion were the inability to secure an operative view, lack of operating space, and adhesions. The mean length of stay was 3 (2.1) days. The complication rate was 5.7%, with one postoperative death. The CUSUM analysis for GL cholecystectomy showed a longer learning curve for operative time and few conversions. The learning curve for GL tubal ligation was relatively shorter. CONCLUSION: Gasless laparoscopy can be safely implemented in the rural settings of Northeast India with appropriate training programs. Careful case selection is essential during the early stages of the surgical learning curve.

Learning curve of robotic rectal surgery using risk-adjusted cumulative summation: a 5-year institutional experience.

PURPOSE: Outline learning phases of robot-assisted laparoscopic surgery for rectal cancer and compare surgical and clinical outcomes between each phase of robot-assisted laparoscopic surgery and the mastery phase of conventional laparoscopic surgery. METHODS: From 2015 to 2020, 210 patients underwent rectal cancer surgery at Sendai Medical Center. We performed conventional laparoscopic surgery in 110 patients and, laparoscopic surgery in 100 patients. The learning curve was evaluated using the cumulative summation method, risk-adjusted cumulative summation method, and logistic regression analysis. RESULTS: The risk-adjusted cumulative summation learning curve was divided into three phases: phase 1 (cases 1-48), phase 2 (cases 49-80), and phase 3 (cases 81-100). Duration of hospital stay (13.1 days vs. 18.0 days, respectively; p = 0.016) and surgery (209.1 min vs. 249.5 min, respectively; p = 0.045) were significantly shorter in phase 3 of the robot-assisted laparoscopic surgery group than in the conventional laparoscopic surgery group. Blood loss volume was significantly lower in phase 1 of the robot-assisted laparoscopic surgery group than in the conventional laparoscopic surgery group (17.7 ml vs. 79.7 ml, respectively; p = 0.036). The International Prostate Symptom Score was significantly lower in the robot-assisted laparoscopic surgery group (p = 0.0131). CONCLUSIONS: Robot-assisted laparoscopic surgery for rectal cancer was safe and demonstrated better surgical and clinical outcomes, including a shorter hospital stay, less blood loss, and a shorter surgical duration, than conventional laparoscopic surgery. After experience with at least 80 cases, tactile familiarity can be acquired from visual information only (visual haptic feedback). CLINICAL TRIAL REGISTRATION: UMIN reference no. UMIN000019857.

Cumulative Sum Analysis of Learning Curve Process for Vaginal Natural Orifice Transluminal Endoscopic Surgery Hysterectomy.

STUDY OBJECTIVE: This study aimed to evaluate the learning curve of vaginal natural orifice transuminal endoscopic surgery (vNOTES) hysterectomy in expert minimal invasive and vaginal surgery team. DESIGN: This is a cohort study on a retrospective analysis. SETTING: Department of Obstetrics and Gynecology of Cannizzaro Hospital in Catania Italy. PATIENTS: First 50 women underwent vNOTES hysterectomy between February 2021 and February 2022. INTERVENTION: vNOTES hysterectomy performed by a team with optimal skills in laparoscopic and vaginal surgery. MEASUREMENT AND MAIN RESULTS: Primary outcome was surgical time. Secondary outcomes were intraoperative and postoperative complications, length of hospitalization, and first 24-hour postoperative pain. All patients underwent hysterectomy for benign indications: 27 fibromatosis, 13 metrorrhagia, and 10 precancerous. Concomitant procedures have been bilateral adnexectomy in 35 cases and bilateral salpingectomy in 15 cases. The median age was 51 years (range, 42-64). Median body mass index was 26 kg/m2 (range, 21-42). The median operative time was 75 minutes (range, 40-110). The median hospital stay was 2 days (range, 1-4). There was 1 intraoperative adverse event (bladder lesion) and 1 postoperative grade 3 complication (hemoperitoneum). The median visual analog scale score for pain assessment during the first 24 hours after surgery was 3 (range, 1-6). The experience in our surgical center with the first 25 vNOTES hysterectomies showed an accumulation of initial experience in the first 5 cases with stable operating time and a gradual reduction of mean operating time in the subsequent 17 surgeries. The learning curve plotted by cumulative sum analysis shows 3 phases: phase 1 of competence (cases 1-5), phase 2 of proficiency (cases 6-26), and phase 3 of mastering the procedure (after the 31st case) with the management of more complex cases. CONCLUSION: vNOTES hysterectomy is a feasible and reproducible approach for benign indications with a short learning curve and low rate of perioperative complications. For a team skilled in minimally invasive surgery, 5 cases are required to rich competence and 25 to rich proficiency in vNOTES hysterectomy. Mastering phase, with the introduction of more complex cases, should be addressed after 30 surgeries.

Anastomotic time was associated with postoperative complications: a cumulative sum analysis of thoracoscopic repair of tracheoesophageal fistula in a single surgeon's experience.

PURPOSE: This study aimed to evaluate the learning curve of thoracoscopic repair of tracheoesophageal fistula (TEF) by a single surgeon using a cumulative sum (CUSUM) analysis. METHODS: Prospective clinical data of consecutive Gross type-C TEF repairs performed by a pediatric surgeon from 2010 to 2020 were recorded. CUSUM charts for anastomosis and operating times were generated. The learning curves were compared with the effect of accumulation based on case experience. RESULTS: For 33 consecutive cases, the mean operative and anastomosis times were 139 ± 39 min and 3137 ± 1110 s, respectively. Significant transitions beyond the learning phase for total operating and anastomosis times were observed at cases 13 and 17. Both the total operating time and anastomosis time were significantly faster in the proficiency improvement phase than in the initial learning phase. Postoperative complications significantly decreased after the initial anastomosis learning phase but not after the initial total operating learning phase. CONCLUSIONS: Thoracoscopic repair of TEF is considered safe and feasible after 13 cases, where the surgeon can improve their proficiency with the total operation procedure, and 17 cases, which will enable the surgeon to achieve proficiency in anastomosis. Postoperative complications significantly decreased after gaining familiarity with the anastomosis procedure through the learning phase.

First assistant experience in total laparoscopic pancreaticoduodenectomy: accelerating the learning curve for an operator.

OBJECTIVE: Compare and analyze clinical data of total laparoscopic pancreaticoduodenectomy (TLPD) cases for surgeons with / without first assistant experience (FAE) in TLPD. Probe influence of FAE in TLPD on the learning curve for an operator. METHODS: The clinical data of 239 patients, that underwent TLPD performed by two surgeons between January 2017 and January 2022) in our department, were consecutively collected and divided into two groups (A and B). Group A cases were operated by Surgeon A, with FAE of 57 TLPDs in our department prior to initial TLPD as an operator. Group B cases were operated by Surgeon B with no FAE of TLPD. Cumulative sum (CUSUM) method developed learning curves. Clinical data and both surgeons' learning curves were statistically compared between both groups. RESULTS: Between both groups, no statistically significant variations were observed for pre-operative health conditions. Reduced surgical duration, blood loss and transfusion volume during surgery, together with reductions in major post-operative complication rates and reduced hospital/ICU stays were identified within Group A, having statistically significant variations. The technical plateau phases of the learning curves were approximately 25-41 cases and 35-51 cases, for Surgeon A and Surgeon B, respectively. CONCLUSION: FAE in TLPD can accelerate the learning curve of TLPD for an operator, with safer surgical procedures and enhanced post-operative recovery.

Impact of an emergency endovascular aneurysm repair protocol on 30-day ruptured abdominal aortic aneurysm mortality.

OBJECTIVE: To characterize the longstanding impact of an emergency endovascular aneurysm repair (EVAR) protocol for ruptured abdominal aortic aneurysm (rAAA) on 30-day mortality. METHODS: All adult patients with an rAAA who underwent a surgical or endovascular intervention at a tertiary care center between March 2001 and December 2018 were evaluated. An emergency EVAR protocol was introduced in January 2004. The primary outcome was 30-day mortality, which was calculated using risk-adjusted logistic regression for the preprotocol and postprotocol periods. A risk-adjusted cumulative sum analysis examined changes in 30-day mortality after protocol implementation. RESULTS: We identified 376 patients with rAAA between 2001 and 2018 (75 preprotocol and 301 postprotocol), with a decreasing incidence of rAAA during the study period. The introduction of the protocol in 2004 was associated with increased EVAR use (63.6% vs 6.7%; P < .001). Patients managed according to the protocol were more frequently unstable (systolic blood pressure [SBP] of ≤80 mm Hg, 46.5% postprotocol vs 22.7% preprotocol; P < 0.001), with a lower average SBP (87.4 mm Hg postprotocol vs 106 mm Hg preprotocol; P < .001) and worse renal function (estimated glomerular filtration rate 61.5 mL/min postprotocol vs 83.2 mL/min preprotocol; P < .001). The risk-adjusted 30-day mortality was 23.2% with the emergency EVAR protocol, versus 35.8% preprotocol (P = .0727). A subgroup analysis demonstrated improved the 30-day mortality for unstable patients (SBP of ≤80 mm Hg) at 38.0% (vs 62.4% preprotocol introduction; P = .0190). A cumulative sum analysis demonstrated worse than expected mortality outcomes in the preprotocol period, and stability of surgical performance over 15 years after protocol introduction. CONCLUSIONS: On reflection of a 17-year experience with EVAR for rAAA, the implementation of an emergency EVAR protocol demonstrated stable surgical performance for all patients with an rAAA and evidence of improved 30-day mortality for unstable patients with an rAAA. Since the protocol introduction, EVAR has become a mainstay intervention and, despite an increase in comorbid patients, the overall incidence of rAAA is declining. EVAR should be considered the first-line intervention for the appropriate patient unstable with an rAAA.

First trimester preeclampsia screening and prediction.

Preeclampsia is a major cause of maternal and perinatal morbidity and mortality. Early-onset disease requiring preterm delivery is associated with a higher risk of complications in both mothers and babies. Evidence suggests that the administration of low-dose aspirin initiated before 16 weeks' gestation significantly reduces the rate of preterm preeclampsia. Therefore, it is important to identify pregnant women at risk of developing preeclampsia during the first trimester of pregnancy, thus allowing timely therapeutic intervention. Several professional organizations such as the American College of Obstetricians and Gynecologists (ACOG) and National Institute for Health and Care Excellence (NICE) have proposed screening for preeclampsia based on maternal risk factors. The approach recommended by ACOG and NICE essentially treats each risk factor as a separate screening test with additive detection rate and screen-positive rate. Evidence has shown that preeclampsia screening based on the NICE and ACOG approach has suboptimal performance, as the NICE recommendation only achieves detection rates of 41% and 34%, with a 10% false-positive rate, for preterm and term preeclampsia, respectively. Screening based on the 2013 ACOG recommendation can only achieve detection rates of 5% and 2% for preterm and term preeclampsia, respectively, with a 0.2% false-positive rate. Various first trimester prediction models have been developed. Most of them have not undergone or failed external validation. However, it is worthy of note that the Fetal Medicine Foundation (FMF) first trimester prediction model (namely the triple test), which consists of a combination of maternal factors and measurements of mean arterial pressure, uterine artery pulsatility index, and serum placental growth factor, has undergone successful internal and external validation. The FMF triple test has detection rates of 90% and 75% for the prediction of early and preterm preeclampsia, respectively, with a 10% false-positive rate. Such performance of screening is superior to that of the traditional method by maternal risk factors alone. The use of the FMF prediction model, followed by the administration of low-dose aspirin, has been shown to reduce the rate of preterm preeclampsia by 62%. The number needed to screen to prevent 1 case of preterm preeclampsia by the FMF triple test is 250. The key to maintaining optimal screening performance is to establish standardized protocols for biomarker measurements and regular biomarker quality assessment, as inaccurate measurement can affect screening performance. Tools frequently used to assess quality control include the cumulative sum and target plot. Cumulative sum is a sensitive method to detect small shifts over time, and point of shift can be easily identified. Target plot is a tool to evaluate deviation from the expected multiple of median and the expected median of standard deviation. Target plot is easy to interpret and visualize. However, it is insensitive to detecting small deviations. Adherence to well-defined protocols for the measurements of mean arterial pressure, uterine artery pulsatility index, and placental growth factor is required. This article summarizes the existing literature on the different methods, recommendations by professional organizations, quality assessment of different components of risk assessment, and clinical implementation of the first trimester screening for preeclampsia.

Multidimensional evaluation of the learning curve for laparoscopic complete mesocolic excision for right colon cancer: a risk-adjusted cumulative summation analysis.

AIM: Despite the suggested potential benefit of complete mesocolic excision (CME) for right-sided colon cancer (RCC) for patient survival, concerns about its safety and feasibility have contributed to delayed acceptance of the procedure, especially when performed by a minimally invasive approach. Thus, the aim of this work was to evaluate the actual learning curve (LC) of laparoscopic CME for experienced colorectal surgeons. METHOD: Prospectively collected data for consecutive patients undergoing laparoscopic CME for RCC between October 2015 and January 2021 at our institution, operated on by experienced surgeons, were analysed. A multidimensional assessment of the LC was performed through cumulative sum (CUSUM) and risk-adjusted (RA) CUSUM analysis. RESULTS: Two hundred and two patients operated by on by three surgeons were considered. The CUSUM graphs based on operating time showed one peak of the curve between 17 and 27 cases. The CUSUM graphs based on surgical failure showed one peak of the curve between 20 and 24 cases The RA-CUSUM curve also showed one preeminent peak at 24-33 cases. Based on the CUSUM and RA-CUSUM analyses all the surgeons reached proficiency in 24-33 cases. CONCLUSIONS: Our study showed that an experienced minimally invasive colorectal surgeon acquires proficiency in laparoscopic CME for RCC after performing 24-33 cases.

Evaluation of the learning curve of robot-assisted laparoscopic ventral mesh rectopexy.

BACKGROUND: The current standard treatment for external rectal prolapse and symptomatic high-grade internal rectal prolapse is surgical correction with minimally invasive ventral mesh rectopexy using either laparoscopy or robotic assistance. This study examines the number of procedures needed to complete the learning curve for robot-assisted ventral mesh rectopexy (RVMR) and reach adequate performance. METHODS: A retrospective analysis of all primary RVMR from 2011 to 2019 performed in a tertiary pelvic floor clinic by two colorectal surgeons (A and B) was performed. Both surgeons had previous experience with laparoscopic rectopexy, but no robotic experience. Skin-to-skin operating times (OT) were assessed using LC-CUSUM analyses. Intraoperative and postoperative complications were analyzed using CUSUM analyses. RESULTS: A total of 182 (surgeon A) and 91 (surgeon B) RVMRs were performed in total. There were no relevant differences in patient characteristics between the two surgeons. Median OT was 75 min (range 46-155; surgeon A) and 90 min (range 63-139; surgeon B). The learning curve regarding OT was completed after 36 procedures for surgeon A and 55 procedures for surgeon B. Both before and after completion of the learning curve, intraoperative and postoperative complication rates remained below a predefined acceptable level of performance. CONCLUSIONS: 36 to 55 procedures are required to complete the learning curve for RVMR. The implementation of robotic surgery does not inflict any additional risks on patients at the beginning of a surgeon's learning curve.

Evaluating the learning curve of high intensity focus ultrasound for breast fibroadenoma by CUSUM analysis: a multi-center study.

OBJECTIVE: To explore the learning curve of high intensity focus ultrasound (HIFU) treatment for breast fibroadenoma. METHODS: A database of 110 patients with 255 breast fibroadenomas who underwent HIFU treatment at two different clinical centers (Center 1 and 2) were retrospectively analyzed. The learning curves of HIFU treatment for breast fibroadenoma were drawn by CUSUM analysis in two centers, respectively. According to the inflection point of the learning curves, the treatment was divided into two groups: initial phase and consolidation phase. HIFU treatment parameters were compared between two groups. The effectiveness and safety results were also evaluated. RESULTS: The inflection points of the learning curves were the 60th treatment in Center 1 and the 65th treatment in Center 2. The screening time, treatment time, sonication time and hyperechoic scale change time were significantly shorter in consolidation phase than those in initial phase of the two centers (p < 0.05). There were no differences in non-perfused volume (NPV) ratio and energy effect factor (EEF) between the two groups in Center 1, while in Center 2, these above-mentioned results in consolidation phase led to a greater improvement than those in initial phase. There was no difference of Visual Analogue Scale (VAS) scores and no adverse event observed in both centers. CONCLUSION: HIFU treatment for breast fibroadenoma was effective and safe. The learning curve of HIFU treatment for breast fibroadenoma can be completed after treating 60-65 tumors without increasing the safety risk.

Robotic-assisted minimally invasive Ivor Lewis esophagectomy within the prospective multicenter German da Vinci Xi registry trial.

PURPOSE: Robotic-assisted minimally invasive esophagectomy (RAMIE) has become one standard approach for the operative treatment of esophageal tumors at specialized centers. Here, we report the results of a prospective multicenter registry for standardized RAMIE. METHODS: The German da Vinci Xi registry trial included all consecutive patients who underwent RAMIE at five tertiary university centers between Oct 17, 2017, and Jun 5, 2020. RAMIE was performed according to a standard technique using an intrathoracic circular stapled esophagogastrostomy. RESULTS: A total of 220 patients were included. The median age was 64 years. Total minimally invasive RAMIE was accomplished in 85.9%; hybrid resection with robotic-assisted thoracic approach was accomplished in an additional 11.4%. A circular stapler size of ≥28 mm was used in 84%, and the median blood loss and operative time were 200 (IQR: 80-400) ml and 425 (IQR: 335-527) min, respectively. The rate of anastomotic leakage was 13.2% (n=29), whereas the two centers with >70 cases each had rates of 7.0% and 12.0%. Pneumonia occurred in 19.5% of patients, and the 90-day mortality was 3.6%. Cumulative sum analysis of the operative time indicated the end of the learning curve after 22 cases. CONCLUSIONS: High-quality multicenter registry data confirm that RAMIE is a safe procedure and can be reproduced with acceptable leak rates in a multicenter setting. The learning curve is comparably low for experienced robotic surgeons.

Using CUSUM in real time to signal clinically relevant decreases in estimated glomerular filtration rate.

BACKGROUND: The electronic health record (EHR), utilized to apply statistical methodology, assists provider decision-making, including during the care of chronic kidney disease (CKD) patients. When estimated glomerular filtration (eGFR) decreases, the rate of that change adds meaning to a patient's single eGFR and may represent severity of renal injury. Since the cumulative sum chart technique (CUSUM), often used in quality control and surveillance, continuously checks for change in a series of measurements, we selected this statistical tool to detect clinically relevant eGFR decreases and developed CUSUMGFR. METHODS: In a retrospective analysis we applied an age adjusted CUSUMGFR, to signal identification of eventual ESKD patients prior to diagnosis date. When the patient signaled by reaching a specified threshold value, days from CUSUM signal date to ESKD diagnosis date (earliness days) were measured, along with the corresponding eGFR measurement at the signal. RESULTS: Signaling occurred by CUSUMGFR on average 791 days (se = 12 days) prior to ESKD diagnosis date with sensitivity = 0.897, specificity = 0.877, and accuracy = .878. Mean days prior to ESKD diagnosis were significantly greater in Black patients (905 days) and patients with hypertension (852 days), diabetes (940 days), cardiovascular disease (1027 days), and hypercholesterolemia (971 days). Sensitivity and specificity did not vary by sociodemographic and clinical risk factors. CONCLUSIONS: CUSUMGFR correctly identified 30.6% of CKD patients destined for ESKD when eGFR was > 60 ml/min/1.73 m2 and signaled 12.3% of patients that did not go on to ESKD (though almost all went on to later-stage CKD). If utilized in an EHR, signaling patients could focus providers' efforts to slow or prevent progression to later stage CKD and ESKD.