The learning curve of a novel seven-axis robot-assisted total hip arthroplasty system: a randomized controlled trial.

BACGROUND: The aim of this study was to assess the learning curve of a novel seven-axis robot-assisted total hip arthroplasty (RaTHA) system. METHODS: A total of 59 patients who underwent unilateral total hip arthroplasty at our institution from June 2022 to September 2022 were prospectively included in the study. In this randomized controlled clinical trial, robot-assisted THA (RaTHA) and Conventional THA (CoTHA) were performed using cumulative sum (CUSUM) analysis to evaluate the learning curve of the RaTHA system. The demographic data, preopera1tive clinical data, duration of operation, postoperative Harris Hip Score (HHS), postoperative Western Ontario and McMaster Universities Arthritis Index (WOMAC) score, and duration of operation between the learning stage and the proficiency stage of the RaTHA group were compared between the two groups. RESULTS: The average duration of operation of the RaTHA group was increased by 34.73 min compared with the CoTHA group (104.26 ± 19.33 vs. 69.53 ± 18.38 min, p < 0.01). The learning curve of the RaTHA system can be divided into learning stage and proficiency stage, and the former consists of the first 13 cases by CUSUM analysis. In the RaTHA group, the duration of operation decreased by 29.75 min in the proficiency stage compared to the learning stage (121.12 ± 12.84 vs.91.37 ± 12.92, p < 0.01). CONCLUSIONS: This study demonstrated that the surgical team required a learning curve of 13 cases to become proficient using the RaTHA system. The duration of operation, total blood loss, and drainage gradually shortened (decreased) with the learning curve stage, and the differences were statistically significant. TRIAL REGISTRATION: Number: ChiCTR2200061630, Date: 29/06/2022.

Safety and feasibility of three-dimensional McKeown minimally invasive esophagectomy.

BACKGROUND: To compare the perioperative outcomes from McKeown minimally invasive esophagectomy (MIE) when performed in three-dimensional versus two-dimensional visualization system, and investigate the learning curve of a single surgeon who implemented three-dimensional McKeown MIE. METHODS: A total of 335 consecutive cases (three-dimensional or two-dimensional) were identified. Perioperative clinical parameters were compared and cumulative sum learning curve was plotted. Propensity score matching was used to reduce selection bias from confounding factors. RESULTS: Patients in three-dimensional group were associated with more chronic obstructive pulmonary disease (23.9% vs 3.0%, p < 0.01). After propensity score matching (108 matched patients in each groups), this finding was no longer statistically significant. Comparing to two-dimensional group, significant improvement in total retrieved lymph nodes (28 vs 33, p = 0.003) was observed in three-dimensional group. In addition, more lymph nodes around the right recurrent laryngeal nerve were harvested in three-dimensional group than that in two-dimensional group (p = 0.045). However, there were no significantly differences were found between the two groups in terms of other intraoperative parameters (e.g., operative time) and postoperative relevant outcomes (e.g., lung infection). Furthermore, the change point in the cumulative sum learning curves for intraoperative blood loss and thoracic procedure time was 33 procedures, respectively. CONCLUSION: Three-dimensional visualization system appears to be superior in performing lymphadenectomy during McKeown MIE to that of a two-dimensional technique. For surgeons proficient in performing two-dimensional McKeown MIE, the learning curve for a three-dimensional procedure appears to begin near proficiency after more than 33 cases.

TOETVA: a single surgeon's learning curve and a case report of CASTLE thyroid tumor.

BACKGROUND: Owing to the lack of visible scars, the transoral endoscopic thyroidectomy vestibular approach (TOETVA) offers superior aesthetic outcomes compared to conventional thyroidectomy. Carcinoma showing thymus-like differentiation (CASTLE) represents a rare thyroid gland neoplasm. This study aimed to explore the TOETVA learning curve and present a case report of CASTLE. METHODS: A study with precise 1:1 matching was conducted to assess the procedure safety and cancer control outcomes of TOETVA in comparison to conventional surgery between May 2020 and May 2023. Cumulative sum analysis was employed to optimally fit the learning curve. Subsequently, a case report of CASTLE treated with TOETVA surgery was presented. RESULTS: The mean operative time was longer in the TOETVA group than in the open group. The TOETVA group had a higher incidence of skin numbness and excellent cosmetic outcomes compared to the open group. The learning curves for work area preparation, unilateral thyroid lobectomy, and the entire surgical process were 59, 28, and 50 cases, respectively. There were no differences between the learning and proficient groups, except for operative time, intraoperative blood loss, and drainage volume on the first postoperative day. CONCLUSIONS: A comprehensive analysis of the TOETVA learning curve utilizing cumulative and analytical methods demonstrated the feasibility of TOETVA with regards to surgical integrity, safety, and oncological safety. This study's findings suggest that a surgeon's cumulative number of TOETVA cases exceeding 50 can reach the mastery stage. Moreover, diagnosing CASTLE is challenging and necessitates immunohistochemical detection of relatively specific markers associated with thymic epithelial tumors.

Gasless endoscopic transaxillary thyroid surgery: CUSUM analysis of a single surgeon's experience from 105 preliminary procedures.

BACKGROUND: We aimed to evaluate the feasibility and oncologic safety of gasless endoscopic transaxillary thyroidectomy (TAT) in patients with thyroid diseases. Improvements in surgical techniques were also reported, and the learning curves of gasless endoscopic TAT were further studied. METHODS: An exact 1:1 matching analysis was performed to compare the technical safety and oncologic outcomes between TAT and conventional open surgery. A questionnaire was designed to evaluate the quality of life of enrolled patients. A cumulative summation analysis was designed for the quantitative estimation of the learning curves. RESULTS: A total of 105 consecutive patients who successfully received endoscopic TAT were retrospectively enrolled in the current study. A standard three-step working space making procedure, an approach that does not free the superficial part of the sternal head of the sternocleidomastoid muscle (SCM, NFSSH) and a "point to line to surface" en bloc procedure utilized in lobectomy with ipsilateral central neck dissection (CND), were introduced in our surgical procedures. The mean operation time in the TAT group was significantly longer than that in the conventional open group (86.9 ± 31.3 vs 44.2 ± 8.3, p < 0.001). Significant differences in the complication rate were not found between the two groups. Discomfort in the anterior neck area and SCM was relieved over time in most cases (verbal response scores (VRSs) were gradually decreased over time). The learning curves for working space making, ipsilateral thyroidectomy and the total endoscopic TAT approach were 45 cases, 25 cases and 42 cases, respectively. The operation time in the proficient group was significantly shorter than that in the learning group (67.0 ± 8.4 vs 112.3 ± 35.7, p < 0.001). VRSs in the SCM were significantly lower in the proficient group (for 1 week: 1.25 ± 0.65 vs 2.40 ± 0.63, p < 0.001; for 1 month: 0.81 ± 0.69 vs 1.81 ± 0.40, p < 0.001). CONCLUSIONS: Gasless endoscopic TAT was safe in a cohort of patients with thyroid diseases, with satisfactory surgical outcomes and cosmetic appearance. The learning curve for endoscopic TAT was approximately 42 cases. The proficiency of the endoscopic TAT approach depended primarily on the proficiency of working space making.

Imageless robotic-assisted total knee arthroplasty accurately restores the radiological alignment with a short learning curve: a randomized controlled trial.

PURPOSE: The study compared a novel imageless robotic-assisted total knee arthroplasty (RATKA) and conventional TKA by considering (1) radiological outcomes, (2) outliers of radiological outcomes, and (3) learning curve. METHODS: This prospective randomized controlled study performed by a single surgeon evaluated 152 patients (152 knees): 75 patients undergoing RATKA and 77 patients undergoing conventional TKA. Mechanical alignment, radiological implant positioning, and outliers were analyzed for radiological outcomes. Cumulative summation (CUSUM) analysis was used to assess the learning curve for operative time in RATKA. RESULTS: The RATKA had significantly better accuracy of knee alignment and component positioning than conventional TKA. The hip-knee-ankle axis and implant position outliers were significantly lower in the RATKA, with 94.7% of patients had achieved an overall mechanical alignment within 3° of a neutral mechanical axis. Changes in posterior condylar offset and joint line were significantly lower in the RATKA. A learning curve of seven cases for operative time was obtained for the RATKA. CONCLUSION: The imageless RATKA has better alignment accuracy with a short learning curve; thus, it presents an attractive option for TKA.

Characterizing the learning curve of a virtual intracorporeal suturing simulator VBLaST-SS©.

BACKGROUND: The virtual basic laparoscopic skill trainer suturing simulator (VBLaST-SS©) was developed to simulate the intracorporeal suturing task in the FLS program. The purpose of this study was to evaluate the training effectiveness and participants' learning curves on the VBLaST-SS© and to assess whether the skills were retained after 2 weeks without training. METHODS: Fourteen medical students participated in the study. Participants were randomly assigned to two training groups (7 per group): VBLaST-SS© or FLS, based on the modality of training. Participants practiced on their assigned system for one session (30 min or up to ten repetitions) a day, 5 days a week for three consecutive weeks. Their baseline, post-test, and retention (after 2 weeks) performance were also analyzed. Participants' performance scores were calculated based on the original FLS scoring system. The cumulative summation (CUSUM) method was used to evaluate learning. Two-way mixed factorial ANOVA was used to compare the effects of group, time point (baseline, post-test, and retention), and their interaction on performance. RESULTS: Six out of seven participants in each group reached the predefined proficiency level after 7 days of training. Participants' performance improved significantly (p < 0.001) after training within their assigned group. The CUSUM learning curve shows that one participant in each group achieved 5% failure rate by the end of the training period. Twelve out of fourteen participants' CUSUM curves showed a negative trend toward achieving the 5% failure rate after further training. CONCLUSION: The VBLaST-SS© is effective in training laparoscopic suturing skill. Participants' performance of intracorporeal suturing was significantly improved after training on both systems and was retained after 2 weeks of no training.

Is selective nerve root block necessary for learning percutaneous endoscopic lumbar discectomy: a comparative study using a cumulative summation test for learning curve.

PURPOSE: The aim of this study was to investigate the effect of lumbar spine selective nerve root block (SNRB) experience on the learning efficiency of percutaneous endoscopic lumbar discectomy (PELD) for junior trainees. METHODS: A total of 480 patients undergoing single-level PELD performed by eight junior trainees were included. The trainees were divided into two groups based on whether they had previous SNRB experience (group A, yes; group B, no). Surgical proficiency was defined as total operation time less than 65 minutes and cumulative radiation exposure time no more than 40 seconds. The learning curve was analyzed by cumulative summation (CUSUM) test. Clinical evaluations included Macnab classification, visual analog scale (VAS)-low back score, VAS-leg score, and Oswestry Disability Index (ODI). Follow-up information at 12 months was also obtained. RESULTS: Integral number of cases before achieving an acceptable surgical level in group A (47.75 ± 2.50 cases) was significantly smaller than that in group B (56.50 ± 1.29 cases, p < 0.05), along with less accumulated failure (18.75 ± 0.96 cases vs. 25.50 ± 1.75 cases, p < 0.05). The two groups were comparable in clinical outcomes. Forty-seven cases of complications were observed, with 17 in group A and 30 in group B (p < 0.05). CONCLUSION: Previous experience of SNRB improved the performance of PELD with shorter operation time and less radiation exposure. SNRB practice may reduce the complication rate without a significant effect on the recurrence of symptoms and reoperation.

Validation of the VBLaST pattern cutting task: a learning curve study.

BACKGROUND: Mastery of laparoscopic skills is essential in surgical practice and requires considerable time and effort to achieve. The Virtual Basic Laparoscopic Skill Trainer (VBLaST-PC©) is a virtual simulator that was developed as a computerized version of the pattern cutting (PC) task in the Fundamentals of Laparoscopic Surgery (FLS) system. To establish convergent validity for the VBLaST-PC©, we assessed trainees' learning curves using the cumulative summation (CUSUM) method and compared them with those on the FLS. METHODS: Twenty-four medical students were randomly assigned to an FLS training group, a VBLaST training group, or a control group. Fifteen training sessions, 30 min in duration per session per day, were conducted over 3 weeks. All subjects completed pretest, posttest, and retention test (2 weeks after posttest) on both the FLS and VBLaST© simulators. Performance data, including time, error, FLS score, learning rate, learning plateau, and CUSUM score, were analyzed. RESULTS: The learning curve for all trained subjects demonstrated increasing performance and a performance plateau. CUSUM analyses showed that five of the seven subjects reached the intermediate proficiency level but none reached the expert proficiency level after 150 practice trials. Performance was significantly improved after simulation training, but only in the assigned simulator. No significant decay of skills after 2 weeks of disuse was observed. Control subjects did not show any learning on the FLS simulator, but improved continually in the VBLaST simulator. CONCLUSIONS: Although VBLaST©- and FLS-trained subjects demonstrated similar learning rates and plateaus, the majority of subjects required more than 150 trials to achieve proficiency. Trained subjects demonstrated improved performance in only the assigned simulator, indicating specificity of training. The virtual simulator may provide better opportunities for learning, especially with limited training exposure.

Self-Formation Assessed by Cumulative Summation Test Does Not Reach Recommended Thresholds for Optical Diagnosis of Colorectal Polyps ≤ 7 mm.

BACKGROUND AND AIMS: Accurate optical diagnosis of diminutive polyps would allow implementing a resect and discard strategy. We evaluated the learning curve of a single training session followed by self-education in subjects with no endoscopic experience. METHODS: Learning curves were evaluated in 38 subjects employing learning curve-cumulative summation (LC-CUSUM) tests, with each participant attending one training session regarding narrow band imaging and optical diagnosis and then individually assessing 100 lesions, receiving feedback after each diagnosis. Diagnostic accuracy was subsequently evaluated in 180 patients with lesions ≤ 7 mm. Evaluators predicted each polyp's histology and recommended a surveillance interval. Determinants of accuracy were explored using regression analysis. RESULTS: According to the LC-CUSUM curve, 20 evaluators (52.6%) reached diagnostic competence after 57 lesions (IQR 55-76.5). During the diagnostic performance assessment, 11,666 diagnoses and 6840 follow-up recommendations were generated. Considering high confidence diagnoses, accuracy was 81.3% (80.5-82.1%), negative predictive value (NPV) for rectosigmoid adenomas 78.6% (76.4-80.6%), and sensitivity for adenomas 86.6% (85.8-87.4%). Two (5.3%) evaluators reached a ≥ 90% accuracy, 3 (7.9%) presented a NPV for rectosigmoid adenomas ≥ 90%, and 18 (47.4%) a sensitivity for adenomas ≥ 90%. Multivariable logistic regression showed high confidence and size ≥ 5 mm as the strongest predictors of accuracy. Fifteen (39.5%) evaluators recommended a correct or reduced follow-up interval in over 90% of subjects. CONCLUSIONS: Self-formation after a single training session did not allow most evaluators to reach the required accuracy. LC-CUSUM tests did not identify competent evaluators. Despite these results, 86.7% of follow-up intervals would have been corrected or reduced.

Longitudinal Assessment of Examiner Experience and the Accuracy of Sonographic Fetal Weight Estimation at Term.

OBJECTIVES: To evaluate the influence of examiner experience on the accuracy of sonographic weight estimation and to further analyze examiners' individual learning curves. METHODS: In this multicenter study, 4613 sonographic weight estimations performed by 18 examiners at the beginning of their ultrasound training were included. To assess the effect of experience on the accuracy of weight estimation, a multivariable mixed regression model analysis was performed, with percentage error and absolute percentage error as outcome variables and the examiner, the examiner's experience (number of examinations), birth weight, gestational age, scan-to-delivery interval, and maternal body mass index as fixed effects and the perinatal center as random intercepts. To further analyze the individual learning curves of the examiners, the cumulative summation technique was used. RESULTS: Regression analyses showed a significant influence of the number of examinations on the accuracy of sonographic weight estimation after adjustment for the above-mentioned parameters (P < .001). A typical learning curve with improving accuracy was found until approximately 200 examinations. Between 200 and 300 examinations, the diagnostic performance started to deteriorate again, with a continuous decrease until the end of the study period. Cumulative summation charts representing individual learning curves varied greatly between different examiners. CONCLUSIONS: These findings indicate the great importance of continuous quality control systems in sonographic weight estimation.

Training Performance in Diagnosis of Congenital Uterine Anomalies With 3-Dimensional Sonography: A Learning Curve Cumulative Summation Analysis.

OBJECTIVES: We evaluated learning curve cumulative summation (CUSUM) of 3-dimensional (3D) sonography for diagnosis of congenital uterine anomalies and the deviations of the level of trainees' performance at the control-stage CUSUM. METHODS: First-year (R1), second-year (R2), and third-year (R3) residents in obstetrics and gynecology received a training program to learn how to analyze 3D sonographic volumes and to classify congenital uterine anomalies. Each trainee worked on 155 3D sonographic volumes from preselected patients. Their results were evaluated by learning curve CUSUM and standard CUSUM. The time for each volume analysis was calculated for the expert examiner and the trainees. RESULTS: Trainees R1, R2, and R3 reached competence at the 85th, 58th, and 40th evaluations, respectively, with success rates of 80%, 81%, and 85%, and kept the process under control with error levels of less than 4.5% until the end of the test. The trainees significantly reduced the average time of the evaluation per volume (P < .001). CONCLUSIONS: Learning curve CUSUM provided quantitative indicators of the learning evolution of 3D sonography for diagnosis of congenital uterine anomalies by obstetrics and gynecology residents. The training received by the residents was adequate for diagnosis of congenital uterine anomalies using 3D sonography.

Learning curves in 3-dimensional sonographic follicle monitoring during controlled ovarian stimulation.

OBJECTIVES: Three-dimensional (3D) sonographically based automated volume calculation (SonoAVC; GE Healthcare, Zipf, Austria) is being introduced in folliculometry during ovarian stimulation; however, clear training assessments in this technique are lacking. The learning curve-cumulative summation (LC-CUSUM) test provides a quantitative tool to determine when a trainee has learned a procedure. The aim of this prospective study was to assess 3D SonoAVC LC-CUSUM curves in folliculometry. METHODS: Analyses were performed on 98 oocyte donors by capturing the ovarian image in 3D and applying the 3D SonoAVC software during ovarian stimulation cycles. Each patient was scanned by an expert operator and by a trainee. Independent LC-CUSUM tests for 4 follicular diameters tracked the competency of 3 trainees in 3D SonoAVC. RESULTS: We found that the numbers of sonographic examinations required by the 3 trainees to identify the correct number of follicles of 10 mm or larger were 38, 32, and 28, respectively; for follicles of 14 mm or larger, they were 29, 28, and 28; for follicles of 18 mm or larger, they were 24, 19, and 27; and for follicles of 21 mm or larger, they were 29, 19, and 24. CONCLUSIONS: A variable number of procedures are needed to reach proficiency in 3D SonoAVC, even for trained 2-dimensional sonographers. Assessment of learning curves should be implemented when incorporating 3D SonoAVC in reproduction units.

Cumulative summation analysis of learning curve for endoscopic endonasal transsphenoidal resection of craniopharyngiomas.

Background: To evaluate the cumulative summation (CUSUM) analysis of the learning curve for Endoscopic Endonasal Transsphenoidal resection of craniopharyngioma (EETC). Methods: Retrospectively analyzed the clinical data of 113 patients who underwent EETC by the same neurosurgery team of the first affiliated Hospital of Nanchang University from June 2012 to November 2020. The learning curve was created by the CUSUM method and analyzed, which was divided into two groups: the learning stage and stable stage based on the learning curve trend. The median operation time and minimum surgical case number was calculated and the operation time and postoperative complications were compared between the two groups. Results: The median operation time was 318 min. The best fitting curve equation was y = 227.72 + 49.06x + 0.14x2 - 0.05x3, R2 = 0.949, (p < 0.001). The minimum number of surgical cases was 65. Between the two groups, the operation time decreased from 360.8 ± 106.4 min in the learning group to 281.6 ± 69.9 min in the stable group (p < 0.05). The incidence of postoperative complications (intracranial infection, cerebrospinal fluid rhinorrhea, and diabetes insipidus) was significantly reduced (p < 0.05). Conclusion: The CUSUM learning curve of craniopharyngioma resection via endoscope endonasal transsphenoidal approach could better describe the learning process for a neurosurgeon. The frequency of surgery could be a good factor for strengthening the learning effect and help to shorten the learning time. After 65 cases of EETC, the surgical skills can reach a stable stage, the operation time is obviously shortened, and the postoperative complications are significantly reduced.

Gastroenterology trainees can easily learn histologic characterization of diminutive colorectal polyps with narrow band imaging.

BACKGROUND & AIMS: Little is known about how teaching gastroenterology trainees polyp patterns by using narrow band imaging (NBI) affects their ability to characterize the histology of diminutive colorectal polyps. We developed and tested a tool to teach trainees to characterize the histology of diminutive polyps by using NBI. METHODS: Twelve gastroenterology trainees with varying levels of colonoscopy experience watched a teaching tool that described the NBI criteria to distinguish polyp histology. The trainees then watched 80 videos of NBI examination of diminutive polyps, recording their predictions of polyp histology and their degree of confidence. After each video, an expert provided feedback about actual polyp histology and the NBI criteria that supported each diagnosis. Twelve weeks later, without training or feedback during the interval, the trainees watched the same videos and predicted histologies of the polyps. Performance was evaluated by comparing predicted classification with actual histologic findings. Cumulative sum analysis was used to determine the learning curve for each trainee. RESULTS: Trainees made significant improvements in accuracy and the proportion of high-confidence predictions as they progressed through video blocks during the first session (P < .001). With active feedback, all trainees predicted polyp histologies with >90% accuracy, with a negative predictive value >90% for adenomatous histology. A median of 49 videos was required to achieve competency. For diagnoses made with high confidence, trainee performance exceeded 90% during the first and second sessions. Interobserver agreement was substantial (session 1, κ = 0.71; session 2, κ = 0.70). CONCLUSIONS: We developed a computer-based tool, combined with short videos and active feedback, to train gastroenterologists to identify polyp histology by using NBI. After training, gastroenterology trainees characterized the histology of diminutive polyps with ≥ 90% accuracy.

Do breaks in gastroenterology fellow endoscopy training result in a decrement in competency in colonoscopy?

BACKGROUND: Skills decay without practice, but the degree is task specific. Some experts believe that it is essential to teach endoscopy longitudinally to build and maintain endoscopic skills. OBJECTIVE: To determine whether breaks in gastroenterology fellow endoscopy training are associated with a decrement in competency in independent intubation of the cecum. DESIGN: Observational cohort of colonoscopies performed by gastroenterology fellows. SETTING: Academic fellowship program from July 2010 to March 2012. SUBJECTS: Twenty-four fellows. MAIN OUTCOME MEASUREMENTS: The adjusted change in the slope of cumulative summation learning curves for cecal intubation after breaks in training and the slope at the end of the subsequent endoscopy rotation. RESULTS: A total of 6485 colonoscopies were performed by 24 fellows with 87 breaks in training. The average break was 6 weeks (range 2-36 weeks). Seventy-five percent of the breaks were 8 weeks or less. For every additional 4 weeks, the slope after the break worsened by 0.022 (P = .06, maximum possible change = -1.0 to +1.0). By the end of the subsequent rotation, there was no association between the slope of the learning curve and the length of the break (P = .68). LIMITATIONS: This was an observational study of only 24 fellows with relatively few long breaks. Cecal intubation is only 1 component of overall competency in colonoscopy. CONCLUSIONS: There may be a very small decrement in fellows' abilities to intubate the cecum after a break in endoscopy training. Because these changes are so small, teaching endoscopy in blocks is probably adequate, if necessary to balance other clinical and research experience. However, further research is needed to determine whether a longitudinal endoscopy experience is superior for attaining and maintaining competency, to evaluate the effects of breaks longer than 8 weeks, and to determine whether the effects of breaks depend on the previous volume of experience with colonoscopy.

Learning curve for biportal endoscopic posterior cervical foraminotomy determined using the cumulative summation test.

BACKGROUND: Learning curves describe the rate of performance improvements corresponding to the surgeon's caseload, followed by a plateau where limited further improvements are observed. This study aimed to determine the learning curve for biportal full-endoscopic posterior cervical foraminotomy (BE-PCF) for the unilateral cervical foraminal disc. METHODS: The learning curve was evaluated using a learning curve cumulative summation test (LC-CUSUM). The goal for the operation time was set to 78 min, which is the mean operation time (mOT) of percutaneous full-endoscopic posterior cervical foraminotomy (PE-PCF) performed by a senior surgeon. Moreover, clinical outcomes and post-operative complications were compared between the early and late learning periods 1 year post-operatively. RESULTS: This study enrolled the first 50 patients who underwent single-level BE-PCF, performed by a single surgeon. The LC-CUSUM signalled competency for surgery at the 20th operation, indicating that sufficient evidence was obtained to prove that the surgeon was competent. The mOT was 71.29 ± 11.69 min in BE-PCF, 71.84 ± 12.61 min in the early learning period, and 67.83 ± 10.31 min in the late learning period (p = 0.254). There was no statistical difference in clinical outcomes, visual analogue scale scores, and neck disability index between both periods (p > 0.05). Four complications were recorded throughout the whole period, with three in the early period and one in the late period (p = 0.285). CONCLUSION: Our study shows that BE-PCF has a learning curve of 20 caseloads to achieve 90% proficiency, and it significantly reduces the operation time based on the performance of a senior surgeon proficient in PE-PCF.

An implementation of the learning curve cumulative summation test to evaluate a practicum for endometrial cancer ultrasound staging.

PURPOSE: The learning curve cumulative summation (LC-CUSUM) test is commonly used as a quantitative assessment of the individual learning process. This study aimed to evaluate the skill acquisition process for performing ultrasound staging of endometrial cancer using the LC-CUSUM test. METHODS: Sixty-seven ultrasound examinations performed by two operators were evaluated using the LC-CUSUM test according to their rate of success or failure to correctly stage myometrial invasion, serosa involvement, and pelvic and para-aortic lymph node involvement. The reference standard was the pathologic result. After the learning phase, the cumulative summation (CUSUM) test was applied to assess performance maintenance. RESULTS: The processes achieved satisfactory performance in the majority of the cases according to the established definitions. Operator 1 reached adequate performance within the 30th procedure for all the locations considered, while operator 2 performed fewer than 30 ultrasound examinations by the audit time. The CUSUM test confirmed that the target quality was preserved after the learning phase. Moreover, the ultrasound staging for endometrial cancer was highly accurate. CONCLUSION: Using the LC-CUSUM test made it possible to monitor the achievement and maintenance of a satisfactory performance quantitatively. The LC-CUSUM test could be a valuable instrument to survey diagnostic pathways in gynecological ultrasonography quantitatively.

The learning curve for robot-assisted distal pancreatectomy: a single-center experience of 301 cases.

Robotic distal pancreatectomy (RDP) has become a routine procedure in many pancreatic centers. This study aimed to describe a single-center experience with RDP since the first case, identify the learning curves of operation time and complication rate, and discuss the safety and feasibility of RDP. Methods: We collected and retrospectively analyzed the single-center surgical experience of 301 patients undergoing RDP at Peking Union Medical College Hospital (PUMCH) between 2012 and 2022 and described the change in operation proficiency and occurrence of perioperative complications in this observational study. The learning curve was assessed using the cumulative sum method. Results: We observed a three-phase pattern of RDP learning with operation time, complications, and postoperative pancreatic fistula as indicators and a two-phase pattern for spleening-preserving success. The mean operation time was 3.9 hours. The incidence rate of clinically significant postoperative pancreatic fistula (CRPOPF) was 17.9% and overall Clavien-Dindo complication rate (≥3) was 16.6%. The change of postoperative complicate rate was correlated with percentage of malignant cases. Conclusion: In the last decade, an evident decrease was seen in operation time, complication rate, and an increase in the spleen-preserving rate of distal pancreatectomy. With proper training, RDP is a safe and feasible procedure.

The Learning Curve of Unilateral Biportal Endoscopic (UBE) Spinal Surgery by CUSUM Analysis.

Objective: To assess the learning curve of the unilateral biportal endoscopic (UBE) technique for the treatment of single-level lumbar disc herniation by cumulative summation (CUSUM) method analysis. Methods: A retrospective analysis was conducted to assess 97 patients' general condition, operation time, complications, and curative effect of single segmental UBE surgery performed by a spinal surgeon in his early stage of this technique. The learning curve of operation time was studied using a CUSUM method, and the cut-off point of the learning curve was obtained. Results: The operation time was 30 - 241(97.9 ± 34.7) min. The visual analog scale score of lower limb pain decreased from 5.75 ± 0.81 before the operation to 0.39 ± 0.28 at the last follow-up (P < 0.05). The Oswestry disability index score decreased from 66.48 ± 4.43 before the operation to 14.57 ± 3.99 at the last follow-up (P < 0.05). The CUSUM assessment of operation time revealed the learning curve was the highest in 24 cases. In the learning stage (1-24 cases), the operation time was 120.3 ± 43.8 min. In the skilled stage (25-97 cases), the operation time was 90.5 ± 27.8 min. Conclusions: About 24 cases of single segmental UBE operation are needed to master the UBE technique.

Cumulative Summation Analysis of Learning Curve for Robotic-assisted Hysterectomy in Patients With Gynecologic Tumors.

BACKGROUND/AIM: This study aimed to evaluate the learning curve and perioperative outcomes of robot-assisted hysterectomy (RAH). PATIENTS AND METHODS: We retrospectively analyzed data from 45 patients who underwent RAH using the da Vinci Xi surgical system. The learning curve was evaluated using the cumulative summation method. Demographic data and various perioperative parameters, including total operative time, docking time, and console time, were obtained from the medical records. RESULTS: Cumulative summation analysis indicated that proficiency regarding hysterectomy time was reached after 33 cases. There were two unique phases of the learning curve for console time: the introduction phase identified by the bottom point in the curve, and the proficient phase, identified by an upward line after the bottom point in the curve. There were no significant differences between the two phases in terms of patient age and body mass index. Total operative time, docking time, and console time were significantly decreased in the proficient phase compared with those in the introduction phase. There was a significant reduction in blood loss during operation in the proficient phase. The perioperative complication rates were 12.1% in the introduction phase and 0% in the proficient phase (p=0.5606). No blood transfusion or conversion to laparotomy was required in either phase. CONCLUSION: The introduction and proficient phases identified by cumulative summation analysis demonstrated progressive improvement of surgical performance in surgeons carrying out RAH.