Cumulative Sum Analysis Research Articles

Retrograde Intrarenal Surgery Learning Curves of Urology Residents Supervised by an Experienced Endourologist: An RIRSearch Study

Introduction: Although retrograde intrarenal surgery (RIRS) is being performed with increasing frequency, there are only a limited number of studies about the learning curve (LC). This study aimed to analyze the LC of RIRS for five surgeons who underwent the same training. Materials and Methods: The data of the 410 patients who underwent RIRS between April 2017 and 2022 in a single institution, which were performed consecutively by five surgeons, were analyzed. All 50 cases performed by each surgeon were included and numbered consecutively and separately, according to the date of the operation. The combined stone-free rate (SFR) was calculated for each surgeon’s cases in the same row, and the LCs were created using moving average and cumulative sum (CUSUM) analyses. Separate multivariable analyses identified each period’s (LC vs. beyond) characteristics. Results: The LCs from the combined SFRs reached a plateau after approximately 50 cases for both the CUSUM and the moving average. The effect of stone burden on SFR was more evident in the first 50 cases compared to subsequent cases in the multivariable analyses (p = 0.001 and p = 0.047, respectively). Case order and stone density were independent factors in the first 50 cases (OR: 1.02 [95% CI 1.00–1.04], p = 0.04 and OR: 0.99 [95% CI 0.99–1.00], p = 0.04) but not significant in subsequent cases (OR: 0.97 [95% CI 0.94–1.00], p = 0.1 and OR: 1.00 [95% CI 0.99–1.00], p = 0.7, respectively). Compared to single locations except the lower calyx, the unfavorable effect of the multiple-stone localization on SFR grew in strength after the 50th case (OR: 0.42 [95% CI 0.23–0.78], p = 0.01 and OR: 0.20 [95% CI 0.09–0.46], p < 0.001, respectively). Conclusions: This is the first study reporting on the RIRS LCs of urology residents. While stone burden, density, and multiple-stone localization were the factors determining SFR in the learning period, after completing the LC, the effect of stone burden weakened and multiple-stone localization became stronger.

Robotic Versus Laparoscopic Donor Nephrectomy: A Retrospective Bicentric Comparison of Learning Curves and Surgical Outcomes From 2 High-volume European Centers.

Although laparoscopic donor nephrectomy (LDN) represents the gold-standard technique for kidney living donation, robotic donor nephrectomy (RDN) settled as another appealing minimally invasive technique over the past decades. A comparison between LDN and RDN outcomes was performed. RDN and LDN outcomes were compared, focusing on operative time and perioperative risk factors affecting surgery duration. Learning curves for both techniques were compared through spline regression and cumulative sum models. The study analyzed 512 procedures (154 RDN and 358 LDN procedures) performed between 2010 and 2021 in 2 different high-volume transplant centers. The RDN group presented a higher prevalence of arterial variations (36.2 versus 22.4%; P = 0.001) compared with the LDN cohort. No open conversions occurred; operative time (210 versus 195 min; P = 0.011) and warm ischemia time (WIT; 230 versus 180 s; P < 0.001) were longer in RDN. Postoperative complication rate was similar (8.4% versus 11.5%; P = 0.49); the RDN group showed shorter hospital stay (4 versus 5 d; P < 0.001). Spline regression models depicted a faster learning curve in the RDN group ( P = 0.0002). Accordingly, cumulative sum analysis highlighted a turning point after about 50 procedures among the RDN cohort and after about 100 procedures among the LDN group.Higher body mass index resulted as an independent risk factor for longer operative time for both techniques; multiple arteries significantly prolonged operative time in LDN, whereas RDN was longer in right kidney procurements; both procedures were equally shortened by growing surgical experience. RDN grants a faster learning curve and improves multiple vessel handling. Incidence of postoperative complications was low for both techniques.

Differences in the learning curve of robotic transabdominal preperitoneal inguinal hernia repair according to surgeon’s robotic experience

PurposeIn this study, we aim to analyze the learning curve of each step of robotic transabdominal pre-peritoneal inguinal hernia repair (rTAPP) in two surgeons with varying degrees of expertise with the robotic platform but no experience with laparoscopic hernia repair.MethodsData on 124 rTAPP cases performed by two surgeons were retrospectively reviewed. Cumulative sum (CUSUM) analysis was applied to visualize the learning curve of rTAPP on operation time of each step of the procedure [the peritoneal flap creation (T1), the completion of the critical view of the myopectineal orifice (T2), the mesh application (T3) and the peritoneal flap closure (T4)]. Each intraoperative and postoperative outcome was compared according to surgeon’s experience with the robotic platform and learning phase. The robotic surgeon mentored the surgeon-in-training and was present during all surgeries in his learning period.ResultsThe surgeon in training with the robotic platform showed a learning phase till the 20th procedure followed by a gradual improvement in performances. The expert surgeon showed a learning phase till the 35th procedure after which a constant decrease of operative time was recorded till the last procedure included. The operative times of each step of the procedures of both surgeons were significantly improved after the learning phase. In the late phase, the surgeon in training could achieve operative times in T2 and T3, which are similar to those of an experienced robotic surgeon with no experience with TAPP before the completion of the learning phase.ConclusionsIn conclusion, the learning phase of rTAPP surgery may vary between 20 and 35 cases, depending on the surgeon’s experience in robotic surgery.

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.

Robotic docking time with the Hugo™ RAS system in gynecologic surgery: a procedure independent learning curve using the cumulative summation analysis (CUSUM)

Robot-assisted surgery has been proven to offer improvements in term of surgical learning curve and feasibility of minimally invasive surgery, but has often been criticized for its longer operative times compared to conventional laparoscopy. Additional times can be split into time required for system set-up, robotic arms docking and calibration of robotic instruments; secondly, surgeon’s learning curve. One of the newest systems recently launched on the market is the Hugo™ RAS (MEDTRONIC Inc, United States). As some of the earliest adopters of the Hugo™ RAS system technology, we present our data on robotic docking learning curve for the first 192 gynecologic robotic cases performed at our institution. Our data indicates that robotic set-up and docking with the new Hugo™ RAS robotic surgical system can be performed time-effectively and that the specific robotic docking learning curve is comparable to preexisting data for other platforms. This preliminary insights into this recently released system may be worthwhile for other centers which may soon adopt this new technology and may need some relevant information on topics such as OR times. Further studies are necessary to assess the different features of the Hugo™ RAS considering other technical and surgical aspects, to fully become familiar with this novel technology.

The learning curve for pure retroperitoneoscopic donor nephrectomy by using cumulative sum analysis.

This study aimed to identify a precise learning curve for pure retroperitoneoscopic donor nephrectomy (RDN). Data from 172 consecutive kidney donors who underwent pure RDN between January 2010 and July 2019 were prospectively collected and evaluated. Cumulative sum (CUSUM) analysis was used for testing the operation time. Changepoints were determined by using the r program and BINSEG method. The cohort was divided into three groups - group 1: competence, including the first 10 cases; group 2: 11-48 cases as proficiency; and group 3: the subsequent 124 cases as expert level. Continuous variables were evaluated using one-way ANOVA, and categorical data were evaluated using the Chi-squared test. Right RDN was performed in 39 (22.7%) donors. The eighth patient was converted to open surgery due to vena cava injury and excluded from the CUSUM analysis. Depending on experience in pure RDN, a significant decrease was detected in operative time (p<0.001), warm ischemia time (p=0.006), and blood loss (p<0.001). Recipient complications and graft function were found to be statistically comparable. In our study, the attainment of expertise in pure RDN was observed after performing 50 cases. The transperitoneal technique, which is a feasible alternative, is far more widely used than pure RDN. We believe that understanding the learning curve associated with pure RDN could facilitate the adoption of this approach as a viable alternative to the transperitoneal approach.

Uniportal video-assisted thoracoscopic surgery for lobectomy: the learning curve.

Prior reported learning curves for uniportal video-assisted thoracoscopic lobectomy were predominantly based on surgery duration, whilst reports on complications are limited. Therefore, our study assessed the learning curve based on both technique-related complications and surgery duration. We retrospectively collected data from patients who underwent uniportal video-assisted thoracoscopic lobectomy, between 2015 and 2020. Exclusion criteria were concomitant procedures other than ipsilateral wedge resection, discontinued procedures, or lost to follow-up (<30 days). Learning curves were constructed per surgeon who performed over 20 procedures using non-risk adjusted cumulative sum analysis for technique-related complications and cumulative sum analysis for surgery duration. Based on the literature, an acceptable complication rate was set at 30%, an unacceptable complication rate at 45%, and a mean surgery duration of 145 minutes. Learning curves were constructed for three thoracic surgeons and one fellow who performed 324 uniportal video-assisted thoracoscopic lobectomies in total. Each surgeon was experienced in multiportal video-assisted thoracoscopic lobectomy, the fellow was familiar with basic multiportal video-assisted thoracoscopic procedures. Cumulative sum charts of three surgeons reached a statistically significant technique-related complication rate below 30% between 50 to 96 procedures. Regarding surgery duration, typical learning curves were observed for three surgeons with a transition point between 14 to 26 procedures. Learning of uniportal video-assisted thoracoscopic surgery for lobectomy is safe without unacceptable complication rates and has a declining surgery duration over time for thoracic surgeons with experience in multiportal video-assisted thoracoscopic lobectomies. However, it remains unknown when the different stages of mastery are completed.

The learning curve on robot-assisted transaxillary thyroidectomy performed by a single endocrine surgeon in a third-level institution in Europe: a cumulative sum (CUSUM) analysis

Robot-assisted transaxillary thyroidectomy is widely performed in Asian countries, although it is still under discussion in the Western World. However, there have been few studies reporting on the learning curve of robot-assisted transaxillary thyroidectomy. We used the cumulative sum (CUSUM) analysis to assess the learning curve of gasless robot-assisted transaxillary thyroidectomy at a third-level institution in Europe. We included all consecutive patients operated by a single surgeon without previous experience of robotic surgery from February 2012 to January 2023. The primary endpoint of the study was the learning curve extracted from the median operative time using the CUSUM method for the quantitative assessment. Overall, 583 patients were enrolled. The median operative time for thyroid lobectomy and total thyroidectomy was 70 and 90 min, respectively. The CUSUM analysis showed that the learning curve for thyroid lobectomy and total thyroidectomy is 66 and 56 cases, respectively. Moreover, the presence of thyroiditis resulted associated with shorter operative time for total thyroidectomy (p = 0.044), whereas no factors resulted associated with surgical complications. The learning curve for performing robotic transaxillary thyroid lobectomy for a surgeon without previous robotic experience is 66 cases. After that, 56 cases must be performed to acquire proficiency in robotic transaxillary total thyroidectomy. Training programs may reduce the slope of the learning curve.

Learning Curve of Multiport Robotic Cholecystectomy: A Cumulative Sum Analysis.

To establish the learning curve of multiport robotic cholecystectomy (MRC). A retrospective analysis of patients undergoing MRC was performed. A cumulative sum analysis helped define the learning curve through the evaluation of skin-to-skin (STS) time and postoperative complications rate. Direct comparison of variables was conducted between the phases. Two hundred forty-five MRC cases were included. Average STS and console times were 50.6 and 29.9 minutes, respectively. Cumulative sum analysis established 3 phases with inflection points at cases 84th and 134th. A significant decrease in STS time was observed between the phases. Middle and late phases encompassed patients with higher comorbidities. Two conversions to open were recorded in the early phase. Postoperative complication rates were comparable among the early (2.5%), middle (6.8%), and late (5.6%) phases (P = 0.482). A steady decrease in STS time was observed across the 3 different phases established at the 84th and 134th patients.

Starting a robotic thoracic surgery program: From wedge resection to sleeve lobectomy in six months. Initial conclusions

IntroductionRobot-assisted thoracic surgery (RATS) is a rapidly expanding technique. In our study, we aimed to analyze the results of the process to adopt robotic surgery in our Department of Thoracic Surgery. MethodsThis is an intention-to-treat analysis of a series of consecutive patients operated on using the RATS approach in our hospital from January 2021 to March 2022. Data were registered for patient characteristics, type of surgery, operative times, conversion rate, chest tube duration, length of hospital stay and complications.The IBM SPSS® statistical software was used for the statistical analysis. A cumulative sum analysis of the operating time was performed to define the learning curve. ResultsDuring the study period, 51 patients underwent robotic surgery, including pulmonary and non-pulmonary interventions. In addition, 15 patients (29.4%) underwent non-pulmonary interventions: one pleural (2%), 2 diaphragmatic (3.9%), and 12 mediastinal (23.5%). Among the mediastinal surgeries, one conversion was necessary (8.3%) for a complex vascular malformation, and 11 were completed by RATS, including 7 (58.3%) thymomas, 3 (25%) pleuro-pericardial cysts, and one (8.3%) neurogenic tumor. Mean operative time was 141 min (104–178), mean chest tube duration was 0.9 days (0–2), and mean length of stay was 1.45 days (1–2).Thirty-six patients underwent lung surgery (70.6%). The complete RATS resections (34; 94.4%) included: 3 wedge resections (11.1%), 2 segmentectomies (3.7%), 28 lobectomies (81.5%), and one sleeve lobectomy (3.7%). Mean surgery time was 194.56 min (141–247), chest tube duration was 3.92 days (1–8), and length of stay was 4.6 days (1–8). Complications occurred in 4 patients (11.1%). No 90-day mortalities were registered. ConclusionsThe implementation of RATS was achieved with good clinical results and operative times for all indications. A rapid learning curve was accomplished in short time. Previous VATS experience, patient selection, team training and program continuity are fundamental to successfully develop a RATS program.

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

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

Management and outcomes of gastric leak after sleeve gastrectomy: results from the 2010-2020 national registry.

Management of gastric leak after sleeve gastrectomy (SG) is challenging due to its unpredictable outcomes. We aimed to summarize the characteristics of SG leaks and analyze interventions and corresponding outcomes in a real-world setting. To retrospectively review of 15,721 SG procedures from 2010 to 2020 based on a national registry. A cumulative sum analysis was used to identify a fitting curve of gastric leak rate. The Kaplan-Meier method and log-rank tests were performed to calculate and compare the probabilities of relevant outcomes. The logistic regression analysis was conducted to determine the predictors of acute leaks. A total of 78 cases of SG leaks were collected with an incidence of 0.5% (78/15,721) from this registry (6 patients who had the primary SG in non-participating centers). After accumulating 260 cases in a bariatric surgery center, the leak rate decreased to a stably low value of under 1.17%. The significant differences presented in sex, waist circumference, and the proportion of hypoproteinemia and type 2 diabetes at baseline between patients with SG leak and the whole registry population ( P = 0.005, = 0.026, <0.001, and = 0.001, respectively). Moreover, 83.1% (59/71) of the leakage was near the esophagogastric junction region. Leakage healed in 64 (88.9%, 64/72) patients. The median healing time of acute and non-acute leaks was 5.93 months and 8.12 months, respectively. Acute leak (38/72, 52.8%) was the predominant type with a cumulative reoperation rate >50%, whereas the cumulative healing probability in the patients who required surgical treatment was significantly lower than those requring non-surgical treatment ( P = 0.013). Precise dissection in the His angle area was independently associated with a lower acute leak rate, whereas preservation ≥2 cm distance from the His angle area was an independent risk factor. Male sex, elevated waist circumference, hypoproteinaemia, and type 2 diabetes are risk factors of gastric leaks after SG. Optimizing surgical techniques, including precise dissection of His angle area and preservation of smaller gastric fundus, should be suggested to prevent acute leaks.

Uniportal video-assisted anatomical segmentectomy: an analysis of the learning curve

BackgroundThis study aimed to demonstrate the learning curve of anatomical segmentectomy performed by uniportal video-assisted thoracoscopic surgery (U-VATS).MethodWe conducted a retrospective study of U-VATS segmentectomies performed by the same surgeon between September 2019 and August 2022. The learning curve was demonstrated using risk-adjusted cumulative sum (RA-CUSUM) analysis in terms of perioperative complications, which reflected surgical quality and technique proficiency. The surgical outcomes were also compared between different phases.ResultThe complication-based learning curve of U-VATS segmentectomy could be divided into two phases based on RA-CUSUM analysis: phase I, the initial learning phase (cases 1–50) and phase II, the proficiency phase (cases 51–141). Significantly higher complication rates (24.0 vs. 8.8%, p=0.013), longer surgical times (119.8±31.9 vs. 106.2±23.8 min, p=0.005), and more blood loss (20 [IQR, 20–30] vs. 20 [IQR, 10–20] ml, p=0.003) were observed in phase I than in phase II.ConclusionThe learning curve of U-VATS segmentectomy consists of two phases, and at least 50 cases were required to gain technique proficiency and achieve high-quality surgical outcomes.

Structured training program on confocal laser endomicroscopy for pancreatic cystic lesions: a multicenter prospective study among early-career endosonographers (with video)

Background and aimsThere are limited data about how to teach endosonographers needle-based confocal laser endomicroscopy (nCLE)-guided histologic diagnosis of pancreatic cystic lesions (PCLs). Hence, we developed and tested a structured educational program to train early-career endosonographers in nCLE-guided diagnosis of PCLs. MethodsTwenty-one early-career nCLE-naive endosonographers watched a teaching module outlining nCLE criteria for diagnosing PCLs. Participants then reviewed 80 high-yield nCLE videos, recorded diagnoses, and received expert feedback (phase 1). Observers were then randomized to a refresher feedback session or self-learning at four weeks. Eight weeks after training, participants independently assessed the same 80 nCLE videos without feedback and provided histologic predictions (phase 2). Diagnostic performance of nCLE to differentiate mucinous vs. non-mucinous PCLs and to diagnose specific subtypes were analyzed using histopathology as the gold standard. Learning curves were determined using cumulative sum analysis (CUSUM). ResultsAccuracy and diagnostic confidence for differentiating mucinous vs. non-mucinous PCLs improved as endosonographers progressed through nCLE videos in phase 1 (p<0.001). Similar trends were observed with the diagnosis of PCL subtypes. Most participants achieved competency interpreting nCLE, requiring a median of 38 assessments (range 9-67). During phase 2, participants independently differentiated PCLs with high accuracy (89%), high confidence (83%), and substantial IOA (k=0.63). Accuracy for nCLE-guided PCL subtype diagnosis ranged from 82-96%. The learned nCLE skills did not deteriorate at eight weeks and were not impacted by a refresher session. ConclusionWe developed a practical, effective, and durable educational intervention to train early-career endosonographers in nCLE-guided diagnosis of PCLs.

Learning curve for flexible bronchoscope-guided orotracheal intubation for anesthesiology residents: A cumulative sum analysis.

Endotracheal intubation with a flexible bronchoscope is a well-recognized airway management technique that anesthesiologists must master. Skill acquisition and knowledge must reach an appropriate level before trainees perform independent practice on patients. There are a paucity of evidence-based outcome measures of trainee competence in performing flexible bronchoscopy. The objectives of this study were to 1) construct a learning curve for flexible bronchoscope-guided orotracheal intubation for anesthesiology residents using the CUSUM method and 2) determine the number of procedures required to achieve proficiency. This study included 12 first-year anesthesiology residents with no previous experience with flexible bronchoscopic intubation. Trainees attended theoretical and simulation training and performed flexible bronchoscope-guided orotracheal intubation in adult patients with normal airways under general anesthesia. Number of intubation attempts, intubation success rate, time to intubation, and incidence of dental and mucosal injuries were recorded. The cumulative sum (CUSUM) method was used to evaluate the learning curve of flexible bronchoscope-guided orotracheal intubation. Trainees performed flexible bronchoscope-guided orotracheal intubation on 364 patients. First-attempt intubation success occurred in 317 (87.1%) patients. Second-attempt intubation success occurred in 23 (6.3%) patients. Overall, the flexible bronchoscope-guided orotracheal intubation success rate was 93.4% (range, 85.3% to 100%). The mean number of orotracheal intubation procedures per trainee was 31 ± 5 (range, 23 to 40). All trainees crossed the lower decision boundary (H0) after 15.1 ± 5.6 procedures (range, 8 to 25 procedures). There was a significant decrease in median intubation time [39s (IQR: 30, 50) vs. 76s (IQR: 54, 119)] (P < 0.001) after crossing the lower decision boundary (H0) compared to before. There were no dental, mucosa, arytenoid or vocal cord trauma events associated with intubation. Learning curves constructed with CUSUM analysis showed that all trainees (anesthesiologist residents) included in this study achieved competence (intubation success rates ≥ 80%) in flexible bronchoscope-guided orotracheal intubation. Trainees needed to perform 15 (range, 8 to 25) procedures to achieve proficiency. There was wide variability between trainees. Trial registration: Chinese Clinical Trial Register, ChiCTR 2000032166.

Short learning curve in transition from laparoscopic to robotic-assisted rectal cancer surgery: a prospective study from a Finnish Tertiary Referral Centre.

The narrow pelvis causes special challenges in surgery, and robotic-assisted surgery has been proven beneficial in these circumstances. While robotic surgery has some specific advantages in rectal cancer surgery, there is still limited evidence of the learning curve of the technique involved. The aim here was to study the transition from laparoscopic to robotic-assisted surgery among experienced laparoscopic surgeons. The data for this study were collected from a prospectively compiled register that includes patients operated on by the Da Vinci Xi robot in Tampere University Hospital. Each consecutive rectal cancer patient was included. The information on the surgical and oncological outcomes was analysed. The learning curve was assessed using cumulative sum (CUSUM) analysis. CUSUM already demonstrated an overall positively sloped curve at the beginning of the study, with neither the conversion rate nor morbidity reaching unacceptable thresholds. Conversions (4%) and postoperative complications (Clavien-Dindo III-IV 15%, no intraoperative complications) were rare. One patient died within one month and the death was not procedure-associated. While surgical and oncological outcomes were similar among all surgeons, the console times showed a decreasing trend and were shorter among those with more experience in laparoscopic rectal cancer surgery. Robotic-assisted rectal cancer surgery can be safely adapted by experienced laparoscopic colorectal surgeons.

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

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

Learning Curve of Intracorporeal Anastomosis in Laparoscopic Colectomy for Right Side Colon Cancer: A Cumulative Sum Analysis.

Recently, laparoscopic colectomy with intracorporeal anastomosis for colon cancer gained popularity due to the evolution of the laparoscopic linear stapler device and improved techniques from laparoscopic surgeons. However, there are technical difficulties associated with intracorporeal anastomosis. The aim of the study was to clarify the number of cases that are required for laparoscopic surgeons to master the technique of intracorporeal anastomosis in right side colon cancer. In this retrospective single-center study, 51 consecutive patients who underwent intracorporeal overlap anastomosis, between July 2018 and March 2020, by one laparoscopic surgeon were selected. Clinicopathological and perioperative data were obtained from our database. The learning curves of intracorporeal anastomosis time (IAT) were created using the cumulative sum (CUSUM) method. The CUSUM score for IAT increased as the number of operative cases progressed, up to the 20th case (Phase 1), after which it started to decrease (Phase 2). Compared to the initial learning phase (Phase 1), the master phase (Phase 2) had a significantly faster IAT (p<0.001), significantly decreased incidence of organ/space surgical site infection (p=0.009), and significantly decreased postoperative hospital stay (p=0.021). Twenty cases were required for a laparoscopic surgeon to achieve expertise when conducting intracorporeal anastomosis in laparoscopic colectomy for right side colon cancer. It was suggested that proficiency in intracorporeal anastomosis may contribute to a reduction in the incidence of organ/space surgical site infections and postoperative hospital stay.

Risk-Adjusted Assessment of the Learning Curve for Pure Laparoscopic Donor Hepatectomy for Adult Recipients.

Studies on pure laparoscopic donor hepatectomy (PLDH) have been reported. However, only few studies have reported on the learning curve of PLDH. In this report, we aimed to determine the learning curve of PLDH in adult patients using cumulative sum (CUSUM) and risk-adjusted CUSUM (RA-CUSUM) analyses. The data of donors who underwent PLDH at a single center between December 2012 and May 2022 were retrospectively reviewed. The learning curve was evaluated using the CUSUM and RA-CUSUM methods based on surgery duration. Forty-eight patients were finally included in the present study. The mean operation time was 393.6 ± 80.3min. PLDH was converted to laparotomy in three cases (6.3%). According to the Clavien-Dindo classification, nine cases (18.8%) had higher-than-grade III postoperative complications and the most frequent complications were biliary complications. The CUSUM graph shows two peaks, at the 13th and 27th case. The multivariate analysis revealed that a body mass index ≥ 23kg/m2 and intraoperative cholangiography were the only factors that were independently associated with longer operation time. Based on these results, an RA-CUSUM analysis was performed to assess the learning curve, which showed a decrease in the learning curve after 33 to 34 PLDH procedures. A learning curve effect was demonstrated in this study after 33 to 34 PLDH procedures. There are relatively many biliary complications, and it is necessary to further examine the method of bile duct transection.

Feasibility and learning curve for robotic surgery in a small hospital: A retrospective cohort study.

Robotic surgery rates, typified by the use of the da Vinci Surgical System, have increased in recent years. However, robotic surgery is mostly performed in large hospitals and has not been fully implemented in small hospitals. Therefore, we aimed to verify the feasibility of robotic surgery in small hospitals and verify the number of cases in which perioperative preparation for robotic surgery is stable by creating a learning curve in small hospitals. Forty robot-assisted rectal cancer surgeries performed in large and small hospitals by a surgeon with extensive experience in robotic surgery were validated. Draping and docking times were recorded as perioperative preparation times. Unexpected surgical interruptions, intraoperative adverse events, conversion to laparoscopic or open surgery, and postoperative complications were recorded. Cumulative sum analysis was used to derive the learning curve for perioperative preparation time. Draping times were significantly longer in the small hospital group (7 vs 10 minutes, P = .0002), while docking times were not significantly different (12 vs 13 minutes, P = .098). Surgical interruptions, intraoperative adverse events, and conversions were not observed in either group. There were no significant differences in the incidence of severe complications (25% [5/20] vs 5% [1/20], P = .184). In the small hospital group, phase I of the draping learning curve was completed in 4 cases, while phase I of the docking learning curve was completed in 7 cases. Robotic surgery is feasible for small hospitals, and the preoperative preparation time required for robotic surgery stabilizes relatively early.