Cumulative Sum Curve Research Articles

263. LEARNING CURVE ANALYSIS USING CUMULATIVE SUM TECHNIQUES FOR ROBOT-ASSISTED MINIMALLY INVASIVE ESOPHAGECTOMY

Abstract Introduction Robot-assisted minimally invasive esophagectomy (RAMIE) has improved the technical difficulty of the conventional minimally invasive esophagectomy, by more precisely operated forceps and stability of the surgical fields. Although it is widely accepted that RAMIE demands excellence in robotic surgery, it is unclear how many cases were needed to reach the proficiency. This study aimed to investigate the learnings curve of two surgeons, with respect to perioperative findings. Methods Patients who underwent RAMIE using a Da Vinci Xi Surgical System between November 2018 and February 2024 were included. Surgeon A introduced RAMIE and Surgeon B started the training of RAMIE after standardization. Both surgeons were certified by the Japan Society for Endoscopic Surgery and qualified surgeon by the Japan Esophageal Society. A cumulative sum (CUSUM) analyses were performed for console time for thoracic procedure to generate the learning curves of each surgeon. The cases before the changepoint of the CUSUM curve was defined as phase I (learning phase), and after the changepoint as phase II (proficiency phase). The perioperative outcomes were compared between the phases. Results Surgeon A and B performed 63 and 33 cases, respectively. Surgeon B started RAMIE under guidance of Surgeon A, who had already experienced 39 cases at that time. CUSUM curve showed that Surgeon B required fewer cases to reach the phase II (proficiency phase) than Surgeon A (16 cases for Surgeon B vs. 27 cases for Surgeon A). There was no significant difference between the phase I and II in patient characteristics including age, sex, tumor location, neoadjuvant chemotherapy, and clinical TNM stages and the extent of lymph node dissection. Total operation time significantly decreased from phase I to phase II: 796 min [730-824] vs. 708 min [627-764]; P<0.01 for Surgeon A, 806 min [751-853] vs. 686 min [635-707]; P<0.01 for Surgeon B. During Phase I, console time of Surgeon B was significantly longer than console time of Surgeon A (408 min [354-432] vs. 360 min [325-385], P<0.01). However, in Phase II, the difference in time attenuated (281 min [255-299] vs. 266 min [244-316], P=0.68). There was no significant difference in intraoperative blood loss or the incidence of postoperative complications including recurrent laryngeal nerve palsy, anastomotic leakage and pneumonia. Conclusion It is suggested that training in standardized surgical procedures for RAMIE under the guidance of an experienced surgeon could accelerate the pace of learning.

Enlightenment of robotic gastrectomy from 527 patients with gastric cancer in the minimally invasive era: 5 years of optimizing surgical performance in a high-volume center - a retrospective cohort study.

Learning curves have been used in the field of robotic gastrectomy (RG). However, it should be noted that the previous study did not comprehensively investigate all changes related to the learning curve. This study aims to establish a learning curve for radical RG and evaluate its effect on the short-term outcomes of patients with gastric cancer. The clinicopathological data of 527 patients who underwent RG between August 2016 and June 2021 were retrospectively analyzed. Learning curves related to the operation time and postoperative hospital stay were determined separately using cumulative sum (CUSUM) analysis. Then, the impact of the learning curve on surgical efficacy was analyzed. Combining the CUSUM curve break points and technical optimization time points, the entire cohort was divided into three phases (patients 1-100, 101-250, and 251-527). The postoperative complication rate and postoperative recovery time tended to decrease significantly with phase advancement ( P <0.05). More extraperigastric examined lymph nodes (LN) were retrieved in phase III than in phase I (I vs. III, 15.12±6.90 vs. 17.40±7.05, P =0.005). The rate of LN noncompliance decreased with phase advancement. Textbook outcome (TO) analysis showed that the learning phase was an independent factor in TO attainment ( P <0.05). With learning phase advancement, the short-term outcomes were significantly improved. It is possible that our optimization of surgical procedures could have contributed to this improvement. The findings of this study facilitate the safe dissemination of RG in the minimally invasive era.

The Learning Curve for Holmium Laser Enucleation of the Prostate: A Single-Center Analysis of Surgical And Functional Outcomes.

Background: To report the surgical and functional outcomes of the holmium laser enucleation of the prostate (HoLEP) surgical program implemented at a high-volume tertiary referral center and to estimate the learning curve (LC) duration for this surgical procedure. Methods: Data of all consecutive patients undergoing HoLEP at the University of Verona between June 2022 and April 2024 were retrieved from a prospectively maintained institutional database of patients undergoing benign prostatic hyperplasia (BPH) surgical treatment. The primary endpoint was functional outcomes evaluation during the surgeons' LC. The secondary endpoint was to define the surgical LC for HoLEP. A multivariable test of means was performed to compare functional outcomes at different time points. After adjusting for potential confounders (age, preoperative pharmacotherapy, and prostate volume), multivariable linear regression models were fitted to evaluate the effect of experience on operative time (OT) and enucleation efficiency. To assess LCs for HoLEP surgery, the non-risk-adjusted cumulative sum (CUSUM) method was used. Results: A statistically significant improvement in International Prostate Symptoms Score (IPSS) score, delta% IPSS score, IPSS quality of life (IPSS-QoL) score, and delta% IPSS-QoL score was observed over the study period. Furthermore, the incidence of irritative symptoms (p < 0.001) and stress incontinence (p = 0.01) significantly decreased over time, with a 12-month incidence of 8.4% and 9.5%, respectively. A statistically significant association between experience and both OT and enucleation efficiency was observed in multivariable linear regression analysis. The CUSUM chart for OT and enucleation efficiency showed a steep initial upward/downward trend of ∼50 cases each, and a plateau until ∼100 procedures are reached, where the breakpoint is recognized for both variables and where the CUSUM curve goes below the locally weighted scatterplot smoothing curve in the corresponding observed-expected CUSUM plot. Conclusions: HoLEP represents an effective treatment for BPH, demonstrating significant improvement in BPH-related symptoms over the study period, despite the considerable LC of ∼50 cases associated with the procedure.

From Novice to Mastery: Learning Curve and Efficacy Analysis of Short-Term Spinal Cord Stimulation for Diabetic Foot Ulcers

To analyze the learning curve of novices in mastering short-term Spinal cord stimulation (st-SCS) for diabetic foot, evaluating the efficacy, safety, and difficulty of this technique. A retrospective review of diabetic foot patients treated with st-SCS at our hospital was conducted. All procedures were performed by the same physician and patients were sequentially numbered according to the order of surgery. Learning curves were plotted using segmented linear regression and cumulative sum curves based on surgery duration. Patients were divided into 2 groups according to the inflection points on the learning curve: the learning group and the mastery group. Pre- and postoperative efficacy indicators were recorded and compared, along with general patient data, perioperative parameters, and incidence of complications. A total of 36 patients were included. Significant improvements were observed post-st-SCS in ulcer size (from 7.00cm2 to 4.00cm2), visual analog scale (from 7.00 to 3.00), foot temperature (from 30.06°C to 32.37°C), and Pittsburgh Sleep Quality Index (from 14.42 to 8.36) (P < 0.05). The physician could proficiently perform st-SCS after 9 cases. Surgery time was significantly shorter in the mastery group (1-9 cases) compared to the learning group (10-36 cases) (28.04 vs. 43.56min, P < 0.05). There were no significant differences between the 2 groups in baseline data, improvement in efficacy indicators, or complications (P > 0.05). St-SCS is beneficial for wound healing, pain relief, improving peripheral circulation, and improving sleep quality. Surgeons can master this simple and safe technique in about 9 cases.

Learning curve of robotic pancreatoduodenectomy by a single surgeon with extensive laparoscopic pancreatoduodenectomy experience.

With the development of robotic systems, robotic pancreatoduodenectomies (RPDs) have been increasingly performed. However, the number of cases required by surgeons with extensive laparoscopic pancreatoduodenectomy (LPD) experience to overcome the learning curve of RPD remains unclear. Therefore, we aimed to analyze and explore the impact of different phases of the learning curve of RPD on perioperative outcomes. Clinical data were prospectively collected and retrospectively analyzed for 100 consecutive patients who underwent RPD performed by a single surgeon. This surgeon had previous experience with LPD, having performed 127 LPDs with low morbidity. The learning curve for RPD was analyzed using the cumulative sum (CUSUM) method based on operation time, and perioperative outcomes were compared between the learning and proficiency phases. Between April 2020 and November 2022, one hundred patients (56 men, 44 women) were included in this study. Based on the CUSUM curve of operation time, the learning curve for RPD was divided into two phases: phase I was the learning phase (cases 1-33) and phase II was the proficiency phase (cases 34-100). The operation time during the proficiency phase was significantly shorter than that during the learning phase. In the learning phase of RPD, no significant increases were observed in estimated blood loss, conversion to laparotomy, severe complications, postoperative pancreatic hemorrhage, clinical pancreatic fistula, or other perioperative complications compared to the proficiency phases of either RPD or LPD. A surgeon with extensive prior experience in LPD can safely surmount the RPD learning curve without increasing morbidity in the learning phase. The proficiency was significantly improved after accumulating experience of 33 RPD cases.

Using risk-adjusted cumulative sum to evaluate surgeon, divisional, and institutional outcomes—a feasibility study

BackgroundFew objective, real-time measurements of surgeon performance exist. The risk-adjusted cumulative sum is a novel method that can track surgeon-level outcomes on a continuous basis. The objective of this study was to demonstrate the feasibility of using risk-adjusted cumulative sum to monitor outcomes after colorectal operations and identify clinically relevant performance variations. MethodsThe National Surgical Quality Improvement Program was queried to obtain patient-level data for 1,603 colorectal operations at a high-volume center from 2011 to 2020. For each case, expected risks of morbidity, mortality, reoperation, readmission, and prolonged length of stay were estimated using the National Surgical Quality Improvement Program risk calculator. Risk-adjusted cumulative sum curves were generated to signal observed-to-expected odds ratios of 1.5 (poor performance) and 0.5 (exceptional performance). Control limits were set based on a false positive rate of 5% (α = 0.05). ResultsThe cohort included data on 7 surgeons (those with more than 20 cases in the study period). Institutional observed versus expected outcomes were the following: morbidity 12.5% (vs 15.0%), mortality 2.5% (vs 2.0%), prolonged length of stay 19.7% (vs 19.1%), reoperation 11.1% (vs 11.3%), and 30-day readmission 6.1% (vs 4.8%). Risk-adjusted cumulative sum accurately demonstrated within- and between-surgeon performance variations across these metrics and proved effective when considering division-level data. ConclusionRisk-adjusted cumulative sum adjusts for patient-level risk factors to provide real-time data on surgeon-specific outcomes. This approach enables prompt identification of performance outliers and can contribute to quality assurance, root-cause analysis, and incentivization not only at the surgeon level but at divisional and institutional levels as well.

A 10-year review on older patients undergoing colorectal cancer surgery: surgeon-led geriatric service and good quality surgery are drivers of good outcomes

BackgroundOlder age and frailty are associated with worse postoperative outcomes and prolonged length of stay (LOS). In this study, we aimed to analyze the long-term outcomes after the implementation of our geriatric surgical service (GSS). MethodsThis was a single-center retrospective study from July 2010 to December 2021 on patients aged ≥75 years or patients aged ≥65 years with frailty. Our GSS includes multidisciplinary assessment and optimization by specialized nurses, physiotherapists, anesthetists, dietitians, and geriatricians. Cumulative sum (CUSUM) analysis was used to assess the performance of our GSS. Our primary outcome was defined as the presence of 30-day mortality, prolonged LOS ≥ 14 days, and/or >10% decrease in the modified Barthel Index at 6 weeks, which depicts the failure of GSS. A downsloping CUSUM curve implies consecutive cases of success. ResultsThere were 233 patients with a mean age of 79.0 ± 4.9 years; of these, 73 patients (31.3%) were frail. The overall 30-day mortality (1.7%), Clavien-Dindo ≥ grade IIIA complications (12.0%), and LOS (median, 7.0 days) were low. The CUSUM analysis showed 3 phases with overall sustained improvement in outcomes. Transient inconsistency in the second phase (during midimplementation of GSS) may be due to the early adoption of laparoscopic surgery (44.6% vs 24.1%; adjusted P =.031) and expansion of service to include patients with higher perioperative risks (weighted Charlson Comorbidity Index score ≥4: 64.9% vs 38.0%; adjusted P =.002) in the second period compared with the first period. The outcomes subsequently improved in the third phase after overcoming the learning curve. ConclusionOur GSS showed sustained performance over the past decade. Good quality surgery and surgeon-led geriatric service are paramount for good postoperative outcomes.

Learning curve of robotic-assisted splenic vessel-preserving spleen-preserving distal pancreatectomy by one single surgeon: a retrospective cohort study

AimSplenic vessel-preserving spleen-preserving distal pancreatectomy (SVP-SPDP) has a lower risk of splenic infarction than the splenicvessel-sacrificing SPDP, but it is more technically demanding. Learning curve of robotic-assisted SVP-SPDP (RSVP-SPDP) remains unreported. This study sought to analyze the perioperative outcomes and learning curve of RSVP-SPDP by one single surgeon.MethodsSeventy-four patients who were intended to receive RSVP-SPDP at the First Affiliated Hospital of Sun Yat-sen University between May 2015 and January 2023 were included. The learning curve were retrospectively analyzed by using cumulative sum (CUSUM) analyses.ResultsSixty-two patients underwent RSVP-SPDP (spleen preservation rate: 83.8%). According to CUSUM curve, the operation time (median, 318 vs. 220 min; P < 0.001) and intraoperative blood loss (median, 50 vs. 50 mL; P = 0.012) was improved significantly after 16 cases. Blood transfusion rate (12.5% vs. 3.4%; P = 0.202), postoperative major morbidity rate (6.3% vs. 3.4%; P = 0.524), and postoperative length-of-stay (median, 10 vs. 8 days; P = 0.120) improved after 16 cases but did not reach statistical difference. None of the patients had splenic infarction or abscess postoperatively.ConclusionRSVP-SPDP was a safe and feasible approach for selected patients after learning curve. The improvement of operation time and intraoperative blood loss was achieved after 16 cases.

First 100 total hip arthroplasties performed by a young surgeon using the direct anterior approach: learning curve and complications.

Most of the reported discussions about the learning curve for the direct anterior approach (DAA) in total hip arthroplasty (THA) have been by experienced surgeons. The study's aim was to describe the learning curve, short-term outcomes, complications, and adaptations to the DAA used in the first 100 THA cases experienced by a young surgeon who had received DAA training for trauma surgeries. This retrospective study summarizes the first 100 consecutive cases experienced by a young surgeon who performed the unilateral DAA for THA between 2019 and 2021. Cumulative sum (CUSUM) analysis was performed to evaluate the learning curve on the basis of operative time and overall complications. The demographics data, short-term outcomes, and complications of the first 50 and second 50 cases were compared. The CUSUM curve declined after 49 and 55 cases, measured by operative time and overall complications, respectively. The median operative time (104 vs. 80min) and intraoperative fluoroscopic time (38 vs. 12s) increased significantly in the first 50 cases compared with the times in the second 50 cases. Complications tended to occur in the first 50 cases (12% vs. 6%), and the overall rate was 9%. Major complications all occurred in the first 50 cases, with a rate of 4%. Only one case, which involved a complicated periprosthetic fracture around the stem that extended to the tip, required the intervention of a senior surgeon. Even after receiving training on the DAA for trauma surgeries, the young surgeon experienced a steep learning curve and more complications in the first 50 cases. The DAA for THA is a technically demanding procedure and may require guidance from an experienced surgeon to manage unexpected complications.

Learning Curves for Robot-Assisted Pedicle Screw Placement: Analysis of Operative Time for 234 Cases.

Robot-assisted pedicle screw placement is associated with greater accuracy, reduced radiation, less blood loss, shorter hospital stays, and fewer complications than freehand screw placement. However, it can be associated with longer operative times and an extended training period. We report the initial experience of a surgeon using a robot system at an academic medical center. We retrospectively reviewed all patients undergoing robot-assisted pedicle screw placement at a single tertiary care institution by 1 surgeon from 10/2017 to 05/2022. Linear regression, analysis of variance, and cumulative sum analysis were used to evaluate operative time learning curves. Operative time subanalyses for surgery indication, number of levels, and experience level were performed. In total, 234 cases were analyzed. A significant 0.19-minute decrease in operative time per case was observed (r = 0.14, P = .03). After 234 operations, this translates to a reduction in 44.5 minutes from the first to last case. A linear relationship was observed between case number and operative time in patients with spondylolisthesis (-0.63 minutes/case, r = 0.41, P < .001), 2-level involvement (-0.35 minutes/case, r = 0.19, P = .05), and 4-or-more-level involvement (-1.29 minutes/case, r = 0.24, P = .05). This resulted in reductions in operative time ranging from 39 minutes to 1.5 hours. Continued reductions in operative time were observed across the learning, experienced, and expert phases, which had mean operative times of 214, 197, and 146 minutes, respectively ( P < .001). General proficiency in robot-assisted surgery was observed after the 20th case. However, 67 cases were required to reach mastery, defined as the inflection point of the cumulative sum curve. This study documents the long-term learning curve of a fellowship-trained spine neurosurgeon. Operative time significantly decreased with more experience. Although gaining comfort with robotic systems may be challenging or require additional training, it can benefit surgeons and patients alike with continued reductions in operative time.

Learning process analysis of robotic lateral pelvic lymph node dissection for local advanced rectal cancer: the CUSUM curve of 78 consecutive patients.

Robotic lateral lymph node dissection (LLND) has been described as a safe and feasible procedure for local advanced rectal cancer. The aim of this study was to evaluate the learning curve for robotic-assisted LLND. We collected data on 78 consecutive patients who underwent robotic-LLND at our hospital. The learning curve was analyzed using the cumulative sum (CUSUM) method to assess changes in the unilateral LLND operative times across the case sequence. Among the 78 patients, 52 underwent bilateral LLND and 26 underwent unilateral LLND. A total of 130 consecutive data were recorded. We arranged unilateral robotic-LLND operative times and calculated cumulative sum values, allowing the differentiation of three phases: phase I (learning period, cases 1-51); phase II (proficiency period, cases 52-83); and phase III (mastery period, cases 84-130). As the learning curve accumulated, the operation time and estimated blood loss of unilateral robotic-LLND decreased significantly with each phase (P < 0.05). By 12months after surgery, the International Prostatic Symptom Score of patients at phase III was significantly lower than at phase I (P < 0.05). The CUSUM curve shows three phases in the learning of robotic-LLND. The estimated learning curve for robotic-assisted rectal-LLND is achieved after 51 cases.

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

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. 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 52weeks, 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). In all procedures, the CUSUM curve of the cohort of surgeons who completed their first 20 procedures in 13weeks 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. 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."

D28. Beating the Curve: Longitudinal Evaluation of Surgeon Proficiency in Microsurgical Breast Reconstruction Post-training

PURPOSE: Microsurgical breast reconstruction is technically demanding, yet the learning curve is not well described. This study aimed to characterize the number of procedures required to master this technique proficiently and efficiently. METHODS: An institutional database was queried from 2006-2018 to identify all abdominally-based, breast free flaps performed by an experienced surgeon (ES) with almost 800 flaps experience and a novice surgeon (NS) entering practice immediately post fellowship. The primary outcome was operative time and secondary outcomes were major/minor complications. Risk-adjusted cumulative sum curves were used to determine expected number of procedures required to attain optimal efficiency, defined as the peak of rapid improvement in operative duration. Linear regression was used to stratify complication rates by procedure number, while controlling for confounders. RESULTS: A total of 1,288 procedures with a mean of 393 minutes (SD 123) were identified for both surgeons. NS’s operative time persistently decreased (-36.6 seconds/procedure, P<0.001) over the study period while ES was unchanged (P=0.353). There was no association between number of procedures and complications or partial/total flap loss (ES: P=0.423; NS: P=0.215). Greatest differential improvement in NS operative times was at approximately 300-350 procedures, 5 years post-training, while ES remained constant. CONCLUSION: Early microsurgical experience intimately correlates with reduced operative times, that peak after completing 300 free flaps, but persist well beyond 600. Gained efficiency does not compromise patient outcomes.

The learning curve for gasless transaxillary posterior endoscopic thyroidectomy for thyroid cancer: a cumulative sum analysis.

Gasless transaxillary posterior endoscopic thyroidectomy (GTPET) is a new approach for thyroid cancer. It allows en bloc resection of the thyroid and central lymph nodes. Few studies have reported on the learning curve for GTPET.We examined the learning curve of GTPET for thyroid cancer by cumulative sum (CUSUM) analysis by retrospectively analyzing patients who underwent hemithyroidectomy with ipsilateral central neck dissection between December 2020 and September 2021 at a tertiary medical center, including the first patient. Moving average analysis and sequential time-block analysis were used for validation. Data on the clinical factors between the two periods were compared. In the overall cohort, the average time for GTPET for thyroid cancer was 113.25min to harvest an average of 6.4 central lymph nodes. The CUSUM curve of the operative time indicated an inflection point after 38 patients. Moving average analysis and sequential time-block analysis validated the number of procedures needed for GTPET proficiency. (124.05min vs. 107.63min for the unproficient period vs. proficient period, respectively; P < 0.001) The number of retrieved lymph nodes was not associated with a certain level of proficiency per the learning curve. The main complication during the surgeon's unproficient period was transient hoarseness (3/38), which was similar to that in their proficient period (2/73, p = 0.336). Proficiency in GTPET is associated with performing more than 38 procedures. Standard course training and instruction on careful management are required prior to introducing the procedure.

Surgeon proficiency gain and survival after gastrectomy for gastric adenocarcinoma: A population-based cohort study

ObjectiveQuality of surgery is essential for survival in gastric adenocarcinoma, but studies examining surgeons’ proficiency gain of gastrectomies are scarce. This study aimed to reveal potential proficiency gain curves for surgeons operating patients with gastric cancer. MethodsPopulation-based cohort study of patients who underwent gastrectomy for gastric adenocarcinoma in Sweden between 2006 and 2015 with follow-up throughout 2020. Data were retrieved from national registries and medical records. Risk prediction models were used to calculate outcome probabilities, and risk-adjusted cumulative sum curves were plotted to assess differences (change points) between observed and expected outcomes. The main outcome was long-term (>3–5 years) all-cause mortality after surgery. Secondary outcomes were all-cause mortality within 30 days, 31–90 days, 91 days to 1 year and>1–3 years of surgery, resection margin status, and lymph node yield. ResultsThe study included 261 surgeons and 1636 patients. The>3- to 5-year mortality was improved after 20 cases, and decreased from 12.4% before to 8.6% after this change point (p = 0.027). Change points were suggested, but not statistically significant, after 22 cases for 30-day mortality, 28 cases for 31- to 90-day mortality, 9 cases for 91-day to 1-year mortality, and 10 cases for>1- to 3-year all-cause mortality. There were statistically significant improvements in tumour-free resection margins after 28 cases (p < 0.005) and greater lymph node yield after 13 cases (p < 0.001). ConclusionsThis study reveals proficiency gain curves regarding long-term survival, resection margin status, and lymph node yield in gastrectomy for gastric adenocarcinoma, and that at least 20 gastrectomies should be conducted with experienced support before doing these operations independently.

CT-guided percutaneous transthoracic needle biopsy (PTNB): A thoracic surgeon's learning curve and experience summary.

Few studies have investigated the learning process of percutaneous transthoracic needle biopsy (PTNB). Here, we aimed to evaluate the number of cases required to achieve proficiency by plotting the learning curve of PTNB. Data were collected from 94 consecutive patients who underwent computed tomography-guided PTNB by a thoracic surgeon at the Affiliated Hospital of Xuzhou Medical University between May 2021 and February 2022. The data collected included patient information, relevant examination results, intraoperative parameters, postoperative complications, and diagnostic results. The inflection points of the cumulative sum curve were around cases 13 and 24, according to which three phases were identified, including phase I, phase II, and phase III. A significant downtrend was observed regarding operative time (phase I, 26.53 ± 9.13 min vs. phase III, 18.42 ± 4.29 min, p < 0.05), rate of false-negative (phase I, 15.4% vs. phase III, 5.7%; p < 0.05), rate of pneumothorax (phase I, 30.8% vs. phase III, 12.9%; p < 0.05), and rate of hemoptysis (phase I, 15.4% vs. phase III, 2.9%; p < 0.05). Thirteen cases were accumulated to lay the technical foundation, and 24 cases were required to achieve proficiency. In this study we summarize our own experience and provide specific guidance for young doctors with no experience in biopsy.

Learning curves of resection and reconstruction procedures in robotic-assisted pancreatoduodenectomy by a single surgeon: a retrospective cohort study of 160 consecutive cases.

Robotic-assisted pancreatoduodenectomy (RPD) has been routinely performed in a few of centers worldwide. This study aimed to evaluate the perioperative outcomes and the learning curves of resection and reconstruction procedures in RPD by one single surgeon. Consecutive patients undergoing RPD by a single surgeon at the First Affiliated Hospital of Sun Yat-sen University (Guangzhou, China) between July 2016 and October 2022 were included. The perioperative outcomes and learning curves were retrospectively analysed by using cumulative sum (CUSUM) analyses. One-hundred and sixty patients were included. According to the CUSUM curve, the times of resection and reconstruction procedures were shortened significantly after 30 cases (median, 284 vs 195 min; P < 0.001) and 45 cases (median, 138 vs 120 min; P < 0.001), respectively. The estimated intraoperative blood loss (median, 100 vs 50 mL; P < 0.001) and the incidence of clinically relevant post-operative pancreatic fistula (29.2% vs 12.5%; P = 0.035) decreased significantly after 20 and 120 cases, respectively. There were no significant differences in the total number of lymph nodes examined, post-operative major complications, or post-operative length-of-stay between the two groups. Optimization of the resection procedure and the acquisition of visual feedback facilitated the performance of RPD. RPD was a safe and feasible procedure in the selected patients.

691: VISUALIZING PEDIATRIC CRITICAL CARE FELLOW TRACHEAL INTUBATION LEARNING CURVES

Introduction: Tracheal intubation (TI) is a life-saving procedure for pediatric intensivists. Developing proficiency in TI is one of the goals in the PCCM fellowship. We aim to develop a dashboard for PCCM fellows to visualize their own learning curves and proactively identify educational needs. We hypothesize majority of the fellows will achieve TI competence during first 12 months of training. Methods: Using the local airway management quality improvement database (a part of National Emergency Airway Registry for Children: NEAR4KIDS), we built a data field for each fellow’s training ID. Using REDCap and R, we developed a cumulative sum (CUSUM) learning curve visualization to achievement of competence level. We piloted the data visualization in a cohort of first year PCCM fellows starting in one of academic year 2019-2021 for their TIs in the PICU for first 12 months. Two levels of TI competence thresholds were a priori defined: 80% success for the first attempt, and 80% success for the course (course is defined as one approach to secure an airway) with both alpha and beta at 0.1. Results: Seventy-one TI courses were performed by six first year fellows (mean 22 TIs, range 14-30 per fellow) with 87 intubation attempts. First attempt success rate was mean 73% (range 57-85%), course success rate was 85% (range 79-93%). CUSUM curves were successfully plotted from the database. Three of six fellows (50%) achieved the competence threshold for the first attempt (80% first attempt success) after 12, 15, and 18 TIs. Five fellows (83%) achieved the competence threshold for the TI course (80% overall success) after 8, 8, 12, 12, 12 TIs. One fellow who did not achieve competence had the lowest number of intubations (n=14). When an alternative competence threshold at 70% for first attempt success is used, five fellows achieved the first attempt competence after 4,4,4,4,7 TIs. Conclusions: The number of tracheal intubations needed to achieve procedural competence amongst first year pediatric critical care fellows is likely variable. Only half of the first year PCCM fellows met the criteria for competence level (80% first attempt success). While repeated procedural attempts may lead to competency for some fellows, individualized educational strategies may be necessary for others.

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

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. 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 > 9.0cm2/hour. The CUSUM method was used to assess the number of ESDs required for achieving proficiency and mastery. 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. The time required to achieve relevant competency in gastric ESD depends on the tumor location.

Safety and efficacy of OAGB/MGB during the learning curve: setting a benchmark in a bariatric center of excellence

Very little has been published on the learning curve (LC) of the One Anastomosis /Mini Gastric Bypass (OAGB/MGB). Aim of this study was to compare perioperative outcomes of OABG/MGBs performed during the LC of an experienced laparoscopic surgeon to global benchmark cut-offs. First 200 patients undergoing OAGB/MGB at our university hospital from 2010 to 2016 were retrospectively included in this study. LC of the surgeon was divided in two groups of 100 consecutive patients each and perioperative outcomes were compared to abovementioned global benchmarks for LSG and RYGB. A cumulative sum (CUSUM) analysis was performed for operative time and hospital stay. Uneventful postoperative recovery was recorded in 95% of patients. All benchmark values for RYGB were met in group 2. Comparison with cut-offs for LSG showed longer hospital stay and operative time in both groups but postoperative rate of complications resulted lower even for Group 1. CUSUM graph of the operative time runs randomly above the predetermined limit till the 40th cases but reaches the plateau after the 115th operation. CUSUM curve of the hospital stay reaches the plateau after the 57th case. OAGB/MGB confirms to be a feasible procedure, which can be safely and effectively performed during the learning curve. However, at least 100 hundred cases are required to reduce operative time and hospital stay.