Multidimensional analyses of the learning curve of robotic low anterior resection for rectal cancer: 3-phase learning process comparison

Textbook outcome after robotic and laparoscopic Ivor Lewis esophagectomy is associated with improved survival: A propensity score-matched analysis

BACKGROUND

Esophagectomy is central to curative therapy for esophageal cancer (EC). Perioperative outcomes affect both disease-free survival (DFS) and overall survival (OS) in patients undergoing oncologic esophageal surgery. The adoption of robotic techniques may improve surgical outcomes; however, the complex nature of perioperative outcomes is not adequately captured by individual quality measures.

METHODS

All EC patients after minimally invasive esophagectomy (MIE) or robotic-assisted MIE (RAMIE) junction between 2015 and 2022 were included. Textbook outcome (TO) was defined as negative resection margin (R0), retrieval of >20 lymph nodes, no major complications, no reinterventions, no intensive care unit readmission, no 30-day readmission or mortality, and hospital stay <21 days. Individual propensity scores were calculated using a logistic regression model. Factors affecting TO were evaluated using a logistic regression model, and a multivariate Cox proportional hazards model was used to evaluate TO and survival.

RESULTS

Of 236 patients included in this study, 106 (44.91%) achieved TO. TO was achieved in 71 patients after MIE (41.21%) and in 31 patients after RAMIE (57.41%; P = .036). RAMIE was associated with achievement of TO (odds ratio, 2.01; 95% confidence interval [CI], 1.07-3.80; P = .031) in the overall cohort. Achievement of TO was due to a reduction in major complications in the RAMIE group. Patients with perioperative TO had higher 3-year DFS and OS rates (univariate analysis [UV]: hazard ratio [HR], 2.49; 95% CI, 1.18-5.26; P = .016; multivariate analysis [MV]: HR, 4.30; 95% CI, 1.60-11.55; P = .004) compared to those without perioperative TO and disease-free survival (UV: HR, 2.28; 95% CI, 1.24-4.19; P = .008; MV: HR, 2.82; 95% CI, 1.26-6.32; P = .011) at the 2-year follow-up.

CONCLUSIONS

RAMIE is associated with increased TO achievement. Achieving TO is associated with enhanced long-term survival in EC patients and warrants continued emphasis on surgical quality improvement.

Left upper division segmentectomy is not a simple procedure: experience from two high-volume centers

BACKGROUND

Whether left upper division segmentectomy (LUDS) is a simple procedure remains controversial. This study aimed to compare the outcomes of LUDS with those of simple segmentectomy (SS) (excluding LUDS) and complex segmentectomy (CS) at two high-volume centers.

METHODS

We retrospectively reviewed 1565 patients who underwent thoracoscopic segmentectomy for early-stage lung cancer between February 2015 and February 2020. Patients were categorized into three groups: LUDS (n = 189), SS (n = 317), and CS (n = 1059). The primary endpoint was defined as the occurrence of any following events: intraoperative complications, postoperative complications, 30-day readmission, and local recurrence.

RESULTS

The rate of the primary endpoint was significantly higher in the LUDS group (14.3%) than in the SS group (7.6%) (P = 0.046) but was comparable between the LUDS and CS groups (14.4%) (P = 1.000). The median operative time in the LUDS group was 135 min, compared to 120 min in the SS group (P < 0.001) and 140 min in the CS group (P = 0.180). The median blood loss and rate of vascular injury in the LUDS group were significantly higher than those in the SS and CS groups (all P < 0.05). Subgroup analysis of the LUDS group demonstrated that the high-experience group had lower rates of primary endpoint and vascular injury, shorter operative time, and reduced blood loss.

CONCLUSIONS

LUDS is an efficient but complex procedure characterized by a long operative time, considerable blood loss, and a potential risk of vascular injury. Performance by experienced surgeons should be considered, as surgical expertise tends to result in improved outcomes.

Influence of surgical start time on the quality of surgery for middle and low rectal cancer: a post hoc analysis of the real trial

BACKGROUND

Surgical start time is considered to influence the quality of surgery due to surgeon fatigue. High-quality studies on middle and low rectal cancer are lacking. The analysis aims to find out the influence of surgical start time on the quality of surgery for middle and low rectal cancer, and whether robotic surgery could avoid the influence.

MATERIALS AND METHODS

This study was a post hoc analysis of the REAL (robotic vs. laparoscopic surgery for middle and low rectal cancer) study, a multicenter, randomized, controlled, unblinded, parallel group, superiority trial. This analysis included the modified intention-to-treat population of the REAL study, who were divided into Group I (the surgeon's first surgery of the day), Group II (the surgeon's second surgery of the day), and Group III (the surgeon's third and subsequent surgeries of the day) based on surgical information registered in the REAL study. The primary outcome was the percentage of patients with a positive circumferential resection margin. The second outcomes were the macroscopic completeness of resection the incidence of intraoperative complications and 30-day postoperative complications.

RESULTS

A total of 1171 patients from the REAL study were included and divided into three groups: 547 (46.7%) in Group I (the surgeon's first surgery), 420 (35.9%) in Group II (the surgeon's second surgery), and 204 (17.4%) in Group III (the surgeon's third and subsequent surgeries). There was a lower percentage of circumferential resection margin (CRM)-positive patients in Group I (3.9%) than in Group II (6.6%, unadjusted P = 0.069) and Group III (8.1%, unadjusted P = 0.027, adjusted P = 0.081). Group I also had fewer intraoperative complications (5.3%) than Group II (8.3%, unadjusted P = 0.060) and Group III (9.3%, unadjusted P = 0.046, adjusted P = 0.138). Macroscopic completeness of resection was not significantly different among the three groups (complete rate: Group I vs. Group II, 94.9% vs. 92.4%, unadjusted P = 0.254; Group I vs. Group III, 94.9% vs. 92.6%, unadjusted P = 0.334; Group II vs. Group III, 92.4% vs. 92.6%, unadjusted P = 0.488). The incidence of 30-day postoperative complications showed no significant difference among the three groups (Group I vs. Group II, 18.5% vs. 20.0%, unadjusted P = 0.547; Group I vs. Group III, 18.5% vs. 22.1%, unadjusted P = 0.268; Group II vs. Group III, 20.0% vs. 22.1%, unadjusted P = 0.551). The quality of robotic surgery was not significantly influenced by surgical start time. For laparoscopic surgery, Group I had a lower CRM positivity rate (4.3%) than Group II (9.4%, unadjusted P = 0.029, adjusted P = 0.087) and Group III (10.4%, unadjusted P = 0.031, adjusted P = 0.047).

CONCLUSION

According to this post hoc analysis of the REAL study, for middle and low rectal cancer surgery, surgical start time could influence surgical quality by affecting surgeon fatigue. Surgeries start later in a day bring worse quality compared to those early in a day. Robotic surgery could reduce this influence to some extent, while laparoscopic surgery is more susceptible.

Systematic review and meta-analysis comparing robotic total mesorectal excision versus transanal total mesorectal excision for rectal cancer

INTRODUCTION

The best approach for total mesorectal excision (TME) remains controversial. Two recently described approaches are robotic TME (RTME) and transanal TME (TaTME). This systematic review and meta-analysis aimed to compare the outcomes between robotic surgery and TaTME in patients undergoing rectal cancer resection.

METHODS

We structured this systematic review and meta-analysis according to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines 2020 and Assessing the Methodological Quality of Systematic Reviews (AMSTAR) guidelines. An electronic search of relevant literature was conducted on 20 May 2023. The protocol was registered in PROSPERO (CRD42023435259).

RESULTS

Eleven eligible nonrandomised studies were included in this study. The study included 2796 patients (RTME = 1800; TaTME = 996). The RTME group had a higher rate of complete TME. However, no significant differences were observed in mortality, morbidity, severe complications, operative time, conversion rate, anastomotic leak, hospital stay, CRM-positive resection margin, distal resection margin, number of harvested lymph nodes, abdominoperineal resection (APR) rate, or local recurrence between the RTME and TaTME groups.

CONCLUSION

The RTME technique may ensure a higher rate of complete TME than TaTME. However, no significant differences were observed in most postoperative outcomes and oncological safety between the RTME and TaTME groups. Evidence does not conclusively favor one technique over the other, highlighting the need for additional randomized controlled trials to better define their roles in rectal cancer surgery.

Learning Curve for Robotic Colorectal Surgery

With the increasing adoption of robotic surgery in clinical practice, institutions intending to adopt this technology should understand the learning curve in order to develop strategies to help its surgeons and operating theater teams overcome it in a safe manner without compromising on patient care. Various statistical methods exist for the analysis of learning curves, of which a cumulative sum (CUSUM) analysis is more commonly described in the literature. Variables used for analysis can be classified into measures of the surgical process (e.g., operative time and pathological quality) and measures of patient outcome (e.g., postoperative complications). Heterogeneity exists in how performance thresholds are defined during the interpretation of learning curves. Factors that influence the learning curve include prior surgical experience in colorectal surgery, being in a mature robotic surgical unit, case mix and case complexity, robotic surgical simulation, spending time as a bedside first assistant, and being in a structured training program with proctorship.

Hospital volume-outcome relationships for robot-assisted surgeries: a population-based analysis

BACKGROUND

Associations between procedure volumes and outcomes can inform minimum volume standards and the regionalization of health services. Robot-assisted surgery continues to expand globally; however, data are limited regarding which hospitals should be using the technology.

STUDY DESIGN

Using administrative health data for all residents of Ontario, Canada, this retrospective cohort study included adult patients who underwent a robot-assisted radical prostatectomy (RARP), total robotic hysterectomy (TRH), robot-assisted partial nephrectomy (RAPN), or robotic portal lobectomy using 4 arms (RPL-4) between January 2010 and September 2021. Associations between yearly hospital volumes and 90-day major complications were evaluated using multivariable logistic regression models adjusted for patient characteristics and clustering at the level of the hospital.

RESULTS

A total of 10,879 patients were included, with 7567, 1776, 724, and 812 undergoing a RARP, TRH, RAPN, and RPL-4, respectively. Yearly hospital volume was not associated with 90-day complications for any procedure. Doubling of yearly volume was associated with a 17-min decrease in operative time for RARP (95% confidence interval [CI] - 23 to - 10), 8-min decrease for RAPN (95% CI - 14 to - 2), 24-min decrease for RPL-4 (95% CI - 29 to - 19), and no significant change for TRH (- 7 min; 95% CI - 17 to 3).

CONCLUSION

The risk of 90-day major complications does not appear to be higher in low volume hospitals; however, they may not be as efficient with operating room utilization. Careful case selection may have contributed to the lack of an observed association between volumes and complications.

Evaluation of the learning curve and complications in unilateral biportal endoscopic transforaminal lumbar interbody fusion: cumulative sum analysis and risk-adjusted cumulative sum analysis

PURPOSE

To evaluate the learning curve and complications in unilateral biportal endoscopic transforaminal lumbar interbody fusion (ULIF) using the Cumulative Sum (CUSUM) analysis and Risk-adjusted Cumulative Sum (RA-CUSUM) analysis.

METHODS

This study retrospectively analyzed 184 consecutive patients who received ULIF in our hospital, including 104 males and 80 females. CUSUM analysis and RA-CUSUM analysis were used to evaluate the learning curve of ULIF based on the operation time and surgical failure rate, respectively. All postoperative complications were defined as surgical failure. Variables of different phases were compared based on the learning curve.

RESULTS

The CUSUM analysis showed the cutoff point for ULIF was 29 cases, and the RA-CUSUM analysis showed the cutoff point for ULIF was 41 cases. Operating time and hospital stay were significantly decreased as the learning curve progressed (P < 0.05). Visual analogue score (VAS) and Oswestry disability index (ODI) at the last follow-up were significantly lower than preoperatively. At the last follow-up, a total of 171 patients reached intervertebral fusion, with a fusion rate of 92.9% (171/184). A total of eleven complications were observed, and RA-CUSUM analysis showed that the incidence of complications in the early phase was 17.07% and in the late phase was 2.6%, with a significant difference (P < 0.05).

CONCLUSION

ULIF is an effective minimally invasive lumbar fusion surgical technique. But a learning curve of at least 29 cases will be required to master ULIF, while 41 cases will be required to achieve a stable surgical success rate.

Hospital learning curves for robot-assisted surgeries: a population-based analysis

BACKGROUND

Robot-assisted surgery has been rapidly adopted. It is important to define the learning curve to inform credentialling requirements, training programs, identify fast and slow learners, and protect patients. This study aimed to characterize the hospital learning curve for common robot-assisted procedures.

STUDY DESIGN

This cohort study, using administrative health data for Ontario, Canada, included adult patients who underwent a robot-assisted radical prostatectomy (RARP), total robotic hysterectomy (TRH), robot-assisted partial nephrectomy (RAPN), or robotic portal lobectomy using four arms (RPL-4) between 2010 and 2021. The association between cumulative hospital volume of a robot-assisted procedure and major complications was evaluated using multivariable logistic models adjusted for patient characteristics and clustering at the hospital level.

RESULTS

A total of 6814 patients were included, with 5230, 543, 465, and 576 patients in the RARP, TRH, RAPN, and RPL-4 cohorts, respectively. There was no association between cumulative hospital volume and major complications. Visual inspection of learning curves demonstrated a transient worsening of outcomes followed by subsequent improvements with experience. Operative time decreased for all procedures with increasing volume and reached plateaus after approximately 300 RARPs, 75 TRHs, and 150 RPL-4s. The odds of a prolonged length of stay decreased with increasing volume for patients undergoing a RARP (OR 0.87; 95% CI 0.82-0.92) or RPL-4 (OR 0.77; 95% CI 0.68-0.87).

CONCLUSION

Hospitals may adopt robot-assisted surgery without significantly increasing the risk of major complications for patients early in the learning curve and with an expectation of increasing efficiency.

Robotic Proctectomy: Beyond the Initial Learning Curve

BACKGROUND

Multiple authors have described an initial learning curve (LC) for robotic proctectomy (RP), but there is scant literature regarding continued technical progression beyond this stage. Total operating time is the most commonly used metric to measure proficiency. Our goal was to examine RP experience after the initial LC looking for evidence of further technical progression.

METHODS

We reviewed our robotic surgery database for a single surgeon during operations 100 through 550 to identify 83 RPs for tumor. These were divided into quartiles by series order, indicating surgeon experience level over time. Demographics and outcomes were compared among the groups. We defined percent console time (PCT) as a new metric. PCT was defined as console time divided by total operative time (TOT).

RESULTS

From March 2014 through March 2019, 450 robotic colorectal operations were performed, including 83 RPs for polyp or cancer. No significant differences were found among the quartiles in regard to demographics, tumor features, hospital stay, conversions, or readmissions. As experience was gained, there were significant increases in intracorporeal anastomosis (ICA), TOT, and PCT. Complications decreased with experience. Number of lymph nodes in the specimen increased. On multivariate analysis, later experience group, body mass index ≥30, and ICA were associated with increased PCT.

DISCUSSION

ICA became a routine part of RP after the initial LC, with increases in TOT and PCT. Number of lymph nodes increased and number and severity of complications decreased with experience. Increased PCT may indicate increased expertise during RP.

Transition from laparoscopic to robotic approach in rectal cancer: a single-center short-term analysis based on the learning curve

As a novel procedure becomes more and more used, knowledge about its learning curve and its impact on outcomes is useful for future implementations. Our aim is (i) to identify the phases of the robotic rectal surgery learning process and assess the safety and oncological outcomes during that period, (ii) to compare the robotic rectal surgery learning phases outcomes with laparoscopic rectal resections performed before the implementation of the robotic surgery program. We performed a retrospective study, based on a prospectively maintained database, with methodological quality assessment by STROBE checklist. All the procedures were performed by the same two surgeons. A total of 157 robotic rectal resections from June 2018 to January 2022 and 97 laparoscopic rectal resections from January 2018 to July 2019 were included. The learning phase was completed at case 26 for surgeon A, 36 for surgeon B, and 60 for the center (both A & B). There were no differences in histopathological results or postoperative complications between phases, achieving the same ratio of mesorectal quality, circumferential and distal resection margins as the laparoscopic approach. A transitory increase of major complications and anastomotic leakage could occur once overcoming the learning phase, secondary to the progressive complexity of cases. Robotic rectal cancer surgery learning curve phases in experienced laparoscopic surgeons was completed after 25-35 cases. Implementation of a robotic rectal surgery program is safe in oncologic terms, morbidity, mortality and length of stay.

Learning curve for robotic rectal cancer resection at a community-based teaching institution

The surgical management of rectal cancer is shifting toward more widespread use of robotics across a spectrum of medical centers. There is evidence that the oncologic outcomes are equivalent to laparoscopic resections, and the post-operative outcomes may be improved. This study aims to evaluate the learning curve of robotic rectal cancer resections at a community-based teaching institution and evaluate clinical and oncologic outcomes. A retrospective review of consecutive robotic rectal cancer resections by a single surgeon was performed for a five-year period. The cumulative sum (CUSUM) for total operative time was calculated and plotted to establish a learning curve. The oncologic and post-operative outcomes for each phase were analyzed and compared. The CUSUM learning curve yielded two phases, the learning phase (cases 1-79) and the proficiency phase (cases 80-130). The median operative time was significantly lower in the proficiency phase. The type of neoadjuvant therapy used between the two groups was statistically different, with chemoradiation being the primary regimen in the learning phase and total neoadjuvant therapy being more common in the proficiency phase. Otherwise, oncologic and overall post-operative outcomes were not significantly different between the groups. Robotic rectal resections can be done in a community-based hospital system by trained surgeons with outcomes that are favorable and similar to larger institutions.

Comparison of short-term outcomes between robot-assisted and laparoscopic rectal surgery for rectal cancer: A propensity score-matched analysis using the Japanese Nationwide diagnosis procedure combination database

Background

The use of robot-assisted surgery for rectal cancer is increasing, but its short-term results remain unclear. We compared the short-term outcomes of robot-assisted and laparoscopic surgery for rectal cancer using a nationwide inpatient database.

Methods

We analyzed patients registered in the Japanese Diagnosis Procedure Combination database who underwent robot-assisted or laparoscopic surgery for rectal cancer from April 2018 to March 2020. Postoperative complication rates, anesthesia time, length of hospital stay, and cost were compared using propensity score matching for low anterior resection (LAR), high anterior resection (HAR), and abdominoperineal resection (APR).

Results

Among 38 090 rectal cancer cases, 1992 LAR, 357 HAR, and 310 APR pairs were generated by propensity score matching and analyzed. Anesthesia time was longer for robot-assisted surgery compared with laparoscopic surgery (LAR: 388.6 vs. 452.8 min, p < 0.001; HAR: 300.9 vs. 393.5 min, p < 0.001; APR: 4478.5 vs. 533.5 min, p < 0.001). Robot-assisted surgery was associated with significantly shorter hospital stay for LAR (22.3 vs. 20.0 days, p < 0.001) and APR (29.2 vs. 25.9 days, p = 0.029). Total costs for LAR were significantly lower for robot-assisted surgery (2031511.6 vs. 1955216.6 JPY, p < 0.001). The complication rates for robot-assisted surgery tended to be fewer than laparoscopic surgery for all procedures, but the differences were not significant.

Conclusions

Although the anesthesia time was longer for robot-assisted surgery, the procedure resulted in shorter hospital stay for LAR and APR, and lower costs for LAR compared with laparoscopic surgery. Robot-assisted surgery can thus help to reduce costs and can be performed safely.

Prospective analysis of impact of learning curve in robotic-assisted rectal surgery in the high-volume Indian tertiary care centre

Background

Minimally invasive surgery in rectal cancer has gained prominence owing to its various advantages in surgical outcomes. Due to rapid adoption of robotics in rectal surgery, we intended to assess the pace in which surgeons gain proficiency using cumulative summation (CUSUM) technique in learning curve.

Materials and Methods

This was a prospective study of 262 rectal cancer cases who underwent robotic-assisted low anterior resection and abdominoperineal resection (RA-LAR and RA-APR). Parameters considered for the study were console time, docking time, lymph nodal yield, total operative time and post-operative outcomes. We used Manipal technique of port placements and modified centroside docking for the procedure.

Results

The mean age of our study was 46.62 ± 5.7 years, the mean body mass index (BMI) was 31.51 ± 3.2 kg/m2. 215 (82.06%) underwent RA-LAR and 47 (17.93%) underwent RA-APR. 2.67% of cases required to open during our initial period. We had three phases of learning curve, initial phase (11th case), plateau phase (29th case) and then phases of mastery (30th case onwards). Our mean total operative time reduced from 5.5 to 3.5 h (210 ± 8.2 min), console time from 4.5 to 2.9 h (174 ± 4.5 min) and docking time from 15 to 9 ± 1 min from 30th case onwards.

Conclusion

RA surgeries for rectal cancer have got good oncological and functional outcomes in high BMI, male pelvis and low rectal cancers. Learning curve can be shortened with constant self-auditing of the surgeon and team with each surgeries performed, reviewing the steps and by improving techniques.

Learning curve for robotic-assisted total mesorectal excision: a multicentre, prospective study

AIM

Robotic-assisted surgery (RAS) is becoming increasingly important in colorectal surgery. Recognition of the short, safe learning curve (LC) could potentially improve implementation. We evaluated the extent and safety of the LC in robotic resection for rectal cancer.

METHOD

Consecutive rectal cancer resections (January 2018 to February 2021) were prospectively included from three French centres, involving nine surgeons. LC analyses only included surgeons who had performed more than 25 robotic rectal cancer surgeries. The primary endpoint was operating time LC and the secondary endpoint conversion rate LC. Interphase comparisons included demographic and intraoperative data, operating time, conversion rate, pathological specimen features and postoperative morbidity.

RESULTS

In 174 patients (69% men; mean age 62.6 years) the mean operating time was 334.5 ± 92.1 min. Operative procedures included low anterior resection (n = 143) and intersphincteric resection (n = 31). For operating time, there were two or three (centre-dependent) LC phases. After 12-21 cases (learning phase), there was a significant decrease in total operating time (all centres) and an increase in the number of harvested lymph nodes (two centres). For conversion rate, there were two or four LC phases. After 9-14 cases (learning phase), the conversion rate decreased significantly in two centres; in one centre, there was a nonsignificant decrease despite the treatment of significantly more obese patients and patients with previous abdominal surgery. There were no significant differences in interphase comparisons.

CONCLUSION

The LC for RAS in rectal cancer was achieved after 12-21 cases for the operating time and 9-14 cases for the conversion rate. RAS for rectal cancer was safe during this time, with no interphase differences in postoperative complications and circumferential resection margin.

A novel training program: laparoscopic versus robotic-assisted low anterior resection for rectal cancer can be trained simultaneously

Background

Current expectations are that surgeons should be technically proficient in minimally invasive low anterior resection (LAR)-both laparoscopic and robotic-assisted surgery. However, methods to effectively train surgeons for both approaches are under-explored. We aimed to compare two different training programs for minimally invasive LAR, focusing on the learning curve and perioperative outcomes of two trainee surgeons.

Methods

We reviewed 272 consecutive patients undergoing laparoscopic or robotic LAR by surgeons A and B, who were novices in conducting minimally invasive colorectal surgery. Surgeon A was trained by first operating on 80 cases by laparoscopy and then 56 cases by robotic-assisted surgery. Surgeon B was trained by simultaneously performing 80 cases by laparoscopy and 56 by robotic-assisted surgery. The cumulative sum (CUSUM) method was used to evaluate the learning curves of operative time and surgical failure.

Results

For laparoscopic surgery, the CUSUM plots showed a longer learning process for surgeon A than surgeon B (47 vs. 32 cases) for operative time, but a similar trend in surgical failure (23 vs. 19 cases). For robotic surgery, the plots of the two surgeons showed similar trends for both operative times (23 vs. 25 cases) and surgical failure (17 vs. 19 cases). Therefore, the learning curves of surgeons A and B were respectively divided into two phases at the 47th and 32nd cases for laparoscopic surgery and at the 23rd and 25th cases for robotic surgery. The clinicopathological outcomes of the two surgeons were similar in each phase of the learning curve for each surgery.

Conclusions

For surgeons with rich experience in open colorectal resections, simultaneous training for laparoscopic and robotic-assisted LAR of rectal cancer is safe, effective, and associated with accelerated learning curves.

Learning curve and short-term clinical outcomes of a new seven-axis robot-assisted total knee arthroplasty system: a propensity score-matched retrospective cohort study

OBJECTIVE

The purpose of the present study was to determine the learning curve for a novel seven-axis robot-assisted (RA) total knee arthroplasty (TKA) system and to explore whether it could provide superior short-term clinical and radiological outcomes compared with conventional surgery.

METHODS

In the present retrospective study, 90 patients who underwent RA-TKA were included in robot-assisted system (RAS) group and 90 patients who underwent conventional TKA were included in the conventional group. The duration of surgery and robot-related complications were recorded to evaluate the learning curve through cumulative sum and risk-adjusted cumulative sum methods. The demographic data, preoperative clinical data, preoperative imaging data, duration of surgery, alignment of the prosthesis, lower limb force line alignment, Knee Society score, 10-cm visual analog scale pain score and range of motion were compared between the RAS and conventional groups. In addition, the proficiency group was compared with the conventional group using propensity score matching.

RESULTS

RA-TKA was associated with a learning curve of 20 cases for the duration of surgery. There was no significant difference in indicators representing the accuracy of the prosthetic installation between the learning and proficiency phases in RA-TKA group patients. A total of 49 patients in the proficiency group were matched with 49 patients from the conventional group. The number of postoperative hip-knee-ankle (HKA) angle, component femoral coronal angle (CFCA), component tibial coronal angle (CTCA), and sagittal tibial component angle (STCA) outliers in the proficiency phase was lower than that in the conventional group, while deviations of the HKA angle, CFCA, CTCA, and STCA in the proficiency phase were significantly lower than those in the conventional group (P < 0.05).

CONCLUSION

In summary, from the learning curve data, 20 cases are required for a surgeon using a novel seven-axis RA-TKA system to enter the proficiency phase. In the proficiency group, compared with the conventional group using propensity score matching, the RAS was found to be superior to the conventional group in prosthesis and lower limb alignment.

Learning Curve for Transanal Total Mesorectal Excision for Low Rectal Malignancy

BACKGROUND

Although transanal total mesorectal excision (TaTME) is a promising treatment for low rectal cancer, it is considered technically demanding, and the number of cases required to become proficient in TaTME remains unknown. The purpose of this study was to assess the TaTME learning curve based on the total mesorectal excision completion time.

STUDY DESIGN

This retrospective analysis comprised 128 individuals who received TaTME between September 2016 and December 2021. The cumulative sum method was used to generate the learning curve. The duration of the procedure from the beginning to the end of the circumferential rendezvous was used to define the total mesorectal excision completion time.

RESULTS

The learning curve consists of 3 phases: phase I (learning phase: cases 1 to 38), phase II (consolidation phase: cases 39 to 70), and phase III (maturing phase: cases 71 to 128). As the phases varied, both the overall operative time and total mesorectal excision completion time decreased considerably. Through the 3 phases of TaTME, intraoperative adverse events decreased, and in phase III, none occurred. Only 1 instance of local recurrence occurred during phase III, and none occurred during phase I or II.

CONCLUSIONS

After 70 operations, the surgeon could join the mastery phase of TaTME based on the total mesorectal excision completion time. After the mastering phase began, there were no intraoperative negative occurrences. From the beginning, the oncological safety could be guaranteed.

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

PURPOSE

Outline learning phases of robot-assisted laparoscopic surgery for rectal cancer and compare surgical and clinical outcomes between each phase of robot-assisted laparoscopic surgery and the mastery phase of conventional laparoscopic surgery.

METHODS

From 2015 to 2020, 210 patients underwent rectal cancer surgery at Sendai Medical Center. We performed conventional laparoscopic surgery in 110 patients and, laparoscopic surgery in 100 patients. The learning curve was evaluated using the cumulative summation method, risk-adjusted cumulative summation method, and logistic regression analysis.

RESULTS

The risk-adjusted cumulative summation learning curve was divided into three phases: phase 1 (cases 1-48), phase 2 (cases 49-80), and phase 3 (cases 81-100). Duration of hospital stay (13.1 days vs. 18.0 days, respectively; p = 0.016) and surgery (209.1 min vs. 249.5 min, respectively; p = 0.045) were significantly shorter in phase 3 of the robot-assisted laparoscopic surgery group than in the conventional laparoscopic surgery group. Blood loss volume was significantly lower in phase 1 of the robot-assisted laparoscopic surgery group than in the conventional laparoscopic surgery group (17.7 ml vs. 79.7 ml, respectively; p = 0.036). The International Prostate Symptom Score was significantly lower in the robot-assisted laparoscopic surgery group (p = 0.0131).

CONCLUSIONS

Robot-assisted laparoscopic surgery for rectal cancer was safe and demonstrated better surgical and clinical outcomes, including a shorter hospital stay, less blood loss, and a shorter surgical duration, than conventional laparoscopic surgery. After experience with at least 80 cases, tactile familiarity can be acquired from visual information only (visual haptic feedback).

CLINICAL TRIAL REGISTRATION

UMIN reference no. UMIN000019857.

The robotic learning curve for a newly appointed colorectal surgeon

Robotic colorectal surgery allows for better ergonomics, superior retraction, and fine movements in the narrow anatomy of the pelvis. Recent years have seen the uptake of robotic surgery in all pelvic surgeries specifically in low rectal malignancies. However, the learning curve of robotic surgery in this cohort is unclear as established training pathways are not formalized. This study looks at the experience and learning curve of a single laparoscopic trained surgeon in performing safe and effective resections, mainly for low rectal and anal malignancies using the da Vinci robotic system by evaluating metrics related to surgical process and patient outcome. A serial retrospective review of the robotic colorectal surgery database, in the University Hospital Coventry and Warwickshire (UHCW), was undertaken. All 48 consecutive cases, performed by a recently qualified colorectal surgeon, were included in our study. The surgical process was evaluated using both console and total operative time recorded in each case along with the adequacy of resections performed; in addition, patient-related outcomes including intraoperative and postoperative complications were analyzed to assess differences in the learning curve. Forty eight sequential recto-sigmoid resections were included in the study performed by a single surgeon. The cases were divided into four cohorts in chronological order with comparable demographics, tumour stage, location, and complexity of the operation (mean age 65, male 79%, and female 29%). The results showed that the mean console time dropped from 3 to 2.5 h, while total operative time dropped from 6 h to 5.5 h as the surgeon became more experienced; however, this was not found to be statistically significant. In addition, no significant difference in pathological staging was seen over the study period. No major intra-op and post-op complications were observed and no 30-day mortality was recorded. Moreover, after 30 cases, the learning curve developed the plateau phase, suggesting the gain of maximum proficiency of skills required for robotic colorectal resections. The learning curve in robotic rectal surgery is short and flattens early; complication rates are low during the learning curve and continue to decrease with time. This shows that with proper training and proctoring, new colorectal surgeons can be trained in a short time to perform elective colorectal pelvic resections.

Assessing the learning curve of robot-assisted total mesorectal excision: a multicenter study considering procedural safety, pathological safety, and efficiency

PURPOSE

Evidence regarding the learning curve of robot-assisted total mesorectal excision is scarce and of low quality. Case-mix is mostly not taken into account, and learning curves are based on operative time, while preferably clinical outcomes and literature-based limits should be used. Therefore, this study aims to assess the learning curve of robot-assisted total mesorectal excision.

METHODS

A retrospective study was performed in four Dutch centers. The primary aim was to assess the safety of the individual and institutional learning curves using a RA-CUSUM analysis based on intraoperative complications, major postoperative complications, and compound pathological outcome (positive circumferential margin or incomplete TME specimen). The learning curve for efficiency was assessed using a LC-CUSUM analysis for operative time. Outcomes of patients before and after the learning curve were compared.

RESULTS

In this study, seven participating surgeons performed robot-assisted total mesorectal excisions in 531 patients. Learning curves for intraoperative complications, postoperative complications, and compound pathological outcome did not exceed predefined literature-based limits. The LC-CUSUM for operative time showed lengths of the learning curve ranging from 12 to 35 cases. Intraoperative, postoperative, and pathological outcomes did not differ between patients operated during and after the learning curve.

CONCLUSION

The learning curve of robot-assisted total mesorectal excision based on intraoperative complications, postoperative complications, and compound pathological outcome did not exceed predefined limits and is therefore suggested to be safe. Using operative time as a surrogate for efficiency, the learning curve is estimated to be between 12 and 35 procedures.

Robotic vs laparoscopic approach for single anastomosis duodenal-ileal bypass with sleeve gastrectomy: a propensity score matching analysis

Biliopancreatic diversion with duodenal switch and single anastomosis duodenal-ileal bypass with sleeve gastrectomy (SADI-S) are technically demanding hypo-absorptive bariatric procedures. They are often indicated in superobese patients (BMI ≥ 50 kg/m²), as robotic platform could improve ergonomics against a thick abdominal wall, preventing bending of instruments and simplifying hand-sewn anastomoses. We aimed to report our experience with robotic SADI-S (R-group) and to compare outcomes with the laparoscopic (L-group) approach. Among 2143 patients who underwent bariatric procedures at our institution between July 2016 and June 2021, 116 (5.4%) consenting patients were scheduled for SADI-S as primary or revisional procedure: 94 L-group, 22 R-group. R-group and L-group patients were matched using PSM analysis to overcome patients selection bias. Postoperative complications, operative time (OT), post-operative stay (POS) and follow-up data were compared. After PSM, 44 patients (22 patients for each group) were compared (Chi-square 0.317, p = 0.985). Median age, gender, median BMI, preoperative rates of comorbidities, previous abdominal bariatric and non-bariatric surgeries and type of surgical procedures (SADI-S/SADI) were comparable. Median OT was shorter in the L-group (130 Vs 191 min, p < 0.001). 30-days' re-operative complications and late complications rates were comparable. At 25-months' mean follow-up, the median Percentage Excess Weight Loss (72%) was comparable between the groups (p = 0.989). L-group and R-group were comparable in terms of re-operative complication rate and short-term outcomes. The robotic platform may increase the rate of single step procedure in challenging cases. Larger studies with longer follow-up and cost-analysis are necessary to draw definitive conclusions.

Learning curves for minimally invasive total mesorectal excision beyond the competency phase - a risk-adjusted cumulative sum analysis of 1000 rectal resections

AIM

The learning curve of total mesorectal excision (TME) by minimally invasive surgery (MIS) beyond the competency phase has not been adequately reported with large numbers or using a statistical control limit. The aim of this work was to study the learning curve of MIS TME in the proficiency phase.

METHOD

Risk-adjusted (RA) cumulative sum (CUSUM) and RA Bernoulli CUSUM charts were plotted for sequential MIS TME performed by a surgical team over 1000 cases. Surgical failure, a composite endpoint of conversions, complications of grade IIIA or above, R1 resections and inadequate nodal yield were used to monitor the performance.

RESULTS

The RA CUSUM detected an inflection point around the 600th operation. Two peaks were identified that could be traced back to probable causes of surgical failure. Similar inflection points were detected at the 450th case for laparoscopic TME and the 367th case for sphincter preservation. No single definite threshold point was noticed for robotic or abdominoperineal operations. At no point did the curves cross the safety threshold. The probability of surgical failure reduced with increasing experience in the multivariate regression (OR 0.899, p = 0.000). This association persisted irrespective of the surgical approach (laparoscopic versus robotic) or the type of operation (sphincter preservation versus abdominoperineal resection).

CONCLUSION

The learning curves for MIS TME did not cross the safety threshold beyond the competency phase. However, a 10% reduction of relative risk in surgical failure was observed for every 100 cases operated on.

Short-term outcomes of robot-assisted versus conventional laparoscopic surgery for mid and low rectal cancer after neoadjuvant chemoradiotherapy: a propensity score-matched analysis

The benefits of robot-assisted laparoscopic surgery (RALS) for rectal cancer remain controversial. Only a few studies have evaluated the safety and feasibility of RALS following neoadjuvant chemoradiotherapy (NCRT). This study aimed to compare the short-term outcomes of RALS versus conventional laparoscopic surgery (CLS) after NCRT for rectal cancer. Propensity score matching of 111 consecutive patients who underwent RALS or CLS after NCRT for rectal adenocarcinoma between February 2014 and February 2022 was performed. Among them, 60 matched patients were enrolled and their short-term outcomes were compared. Although operative time, conversion rate to open laparotomy and blood loss were comparable, the incidence of postoperative complications, including anastomotic leakage, was significantly lower, urinary retention tended to be lower, and the days to soft diet intake and postoperative hospital stay were significantly shorter in the RALS than the CLS group. No postoperative mortality was observed in either group, and there were no significant differences in terms of resection margins and number of lymph nodes dissected. RALS after NCRT for rectal cancer is safe and technically feasible, and has acceptable short-term outcomes. Further studies are required for validation of the long-term oncological outcomes.

Challenges and Learning Curves in Adopting TaTME and Robotic Surgery for Rectal Cancer: A Cusum Analysis

Simple Summary

Rectal cancer surgery remains a challenge and information about the learning curve in adopting new techniques is lacking. This paper analyzes our experience in taTME (since 2015) and robotic surgery (since 2018) at a fully accredited referral center for the treatment of rectal cancer in Spain. In this retrospective study, we aim to analyze the learning curves for taTME and robot-assisted rectal procedures in the incorporation of these platforms into our practice. We sought to describe our team’s experience in incorporating these techniques and to analyze the difficulties that we have had. Hoping that sharing our experience can help other groups improve their results during the difficult initial phase of incorporating new techniques.

Abstract

New techniques are being developed to improve the results of laparoscopic surgery for rectal cancer. This paper analyzes the learning curves for transanal total mesorectal excision (taTME) and robot-assisted surgery in our colorectal surgery department. We analyzed retrospectively data from patients undergoing curative and elective surgery for rectal cancer ≤12 cm from the anal verge. We excluded extended surgeries. We used cumulative sum (CUSUM) curve analysis to identify inflection points. Between 2015 and 2021, 588 patients underwent surgery for rectal cancer at our center: 67 taTME and 79 robot-assisted surgeries. To overcome the operative time learning curve, 14 cases were needed for taTME and 53 for robot-assisted surgery. The morbidity rate started to decrease after the 17th case in taTME and after the 49th case in robot-assisted surgery, but it is much less abrupt in robot-assisted group. During the initial learning phase, the rate of anastomotic leakage was higher in taTME (35.7% vs. 5.7%). Two Urological lesions occurred in taTME but not in robot-assisted surgery. The conversion rate was higher in robot-assisted surgery (1.5% vs. 10.1%). Incorporating new techniques is complex and entails a transition period. In our experience, taTME involved a higher rate of serious complications than robot-assisted surgery during initial learning period but required a shorter learning curve.

Short- and long-term outcomes of robotic-assisted laparoscopic surgery for rectal cancer: A single-center retrospective cohort study

INTRODUCTION

Whether rectal cancer surgery by robotic-assisted laparoscopic surgery provides beneficial advantages remains controversial. Although favorable outcomes in terms of the safety and technical feasibility of robotic-assisted laparoscopic surgery have been demonstrated for rectal cancer, long-term oncological outcomes for robotic-assisted laparoscopic surgery have only been examined in a few studies. This retrospective study of subjects who underwent robotic-assisted laparoscopic surgery evaluated short- and long-term outcomes of consecutive rectal cancer patients.

METHODS

Between November 2016 and January 2020, we analyzed the records of 62 consecutive patients who underwent robotic-assisted laparoscopic surgery for rectal adenocarcinoma without distant metastasis to evaluate short- and long-term outcomes.

RESULTS

Tumors were located in the lower or mid-rectum (88.7%) in most patients. The median operative time was 357 min. No patient received transfusions, and the median blood loss was 10.5 ml. Open laparotomy was not required in any patient. A Clavien-Dindo classification of all grades was observed in 12 patients (19.4%). Positive radial margin was not observed in any patient. Duration of median follow-up was 40.5 mo, while 3-y overall survival and 3-y relapse-free survival rates were 96.8% and 85.0%, respectively. The local recurrence rate was 3.4%.

CONCLUSION

Favorable short- and long-term outcomes demonstrated robotic-assisted laparoscopic surgery was safe and technically feasible for rectal cancer.

Comparison of short-term outcomes of robotic-assisted and conventional laparoscopic surgery for rectal cancer: A propensity score-matched analysis

INTRODUCTION

The advantages of robotic-assisted laparoscopic surgery (RALS) for rectal cancer remain controversial. This study clarified and compared the short-term outcomes of RALS for rectal cancer with those of conventional laparoscopic surgery (CLS).

METHODS

The records of 303 consecutive patients who underwent RALS or CLS for rectal adenocarcinoma between November 2016 and November 2021 were analyzed using propensity score-matched analysis. After matching, 188 patients were enrolled in our study to compare short-term outcomes, such as operative results, postoperative complications, and pathological findings, in each group.

RESULTS

After matching, baseline characteristics were comparable between groups. Although operative time in the RALS group was significantly longer than in the CLS group (p < 0.0001), the conversion rate to open laparotomy and the postoperative complication rate in the RALS group were significantly lower than in the CLS group (p = 0.0240 and p = 0.0109, respectively). Blood loss was comparable between groups. In the RALS group, postoperative hospital stay and days to soft diet were significantly shorter than those in the CLS group (p = 0.0464 and p < 0.0001, respectively). No postoperative mortality was observed in either group and significant differences were observed in resection margins and number of lymph nodes harvested.

CONCLUSION

Robotic-assisted laparoscopic surgery for rectal cancer was safe, technically feasible, and had acceptable short-term outcomes. Further studies are required to validate long-term oncological outcomes.

The learning curve of laparoscopic, robot-assisted and transanal total mesorectal excisions: a systematic review

BACKGROUND

The standard treatment of rectal carcinoma is surgical resection according to the total mesorectal excision principle, either by open, laparoscopic, robot-assisted or transanal technique. No clear consensus exists regarding the length of the learning curve for the minimal invasive techniques. This systematic review aims to provide an overview of the current literature regarding the learning curve of minimal invasive TME.

METHODS

A systematic literature search was performed. PubMed, Embase and Cochrane Library were searched for studies with the primary or secondary aim to assess the learning curve of either laparoscopic, robot-assisted or transanal TME for rectal cancer. The primary outcome was length of the learning curve per minimal invasive technique. Descriptive statistics were used to present results and the MINORS tool was used to assess risk of bias.

RESULTS

45 studies, with 7562 patients, were included in this systematic review. Length of the learning curve based on intraoperative complications, postoperative complications, pathological outcomes, or a composite endpoint using a risk-adjusted CUSUM analysis was 50 procedures for the laparoscopic technique, 32-75 procedures for the robot-assisted technique and 36-54 procedures for the transanal technique. Due to the low quality of studies and a high level of heterogeneity a meta-analysis could not be performed. Heterogeneity was caused by patient-related factors, surgeon-related factors and differences in statistical methods.

CONCLUSION

Current high-quality literature regarding length of the learning curve of minimal invasive TME techniques is scarce. Available literature suggests equal lengths of the learning curves of laparoscopic, robot-assisted and transanal TME. Well-designed studies, using adequate statistical methods are required to properly assess the learning curve, while taking into account patient-related and surgeon-related factors.

Learning Curve of Robotic-Assisted Total Mesorectal Excision for Rectal Cancer

Background

Although some studies have assessed the learning curve of robotic-assisted total mesorectal excision for rectal cancer, most studies included limited sample sizes, no study used postoperative complications as an independent variable to analyze the learning curve of robotic rectal surgery, and no study evaluated the influence of the learning curve on long-term oncologic outcomes.

Methods

Clinical data on consecutive patients who underwent robotic-assisted total mesorectal excision for rectal cancer by a single surgeon between January 2015 and December 2018 at the First Affiliated Hospital of Nanchang University were retrospectively collected. The cumulative sum (CUSUM) and risk-adjusted cumulative sum (RA-CUSUM) were used to visualize the learning curve of operation time and postoperative complications (CD ≥ grade II). Comparisons of clinical outcomes at different learning phases analyzed by RA-CUSUM were performed after propensity score matching.

Results

A total of 389 consecutive patients were included in the analysis. The numbers of patients needed to overcome the learning curves of operation time and postoperative complications of robotic-assisted laparoscopic surgery for rectal cancer were 34 and 36, respectively. The learning process was divided into two phases based on RA-CUSUM: the learning phase (1st-36th cases) and the mastery phase (37th-389th cases). Before matching, the mastery phase had more patients with older age, lower tumor location, and neoadjuvant therapy. After matching, the two phases exhibited similar characteristics. The operation time, intraoperative blood loss, postoperative hospital stay, and postoperative complications in the mastery phase were reduced compared with the learning phase, with a median follow-up of 35 months, and the long-term oncologic outcomes were not significantly different between the two phases.

Conclusions

An experienced laparoscopic surgeon initially implements robotic-assisted total mesorectal excision for rectal cancer, surgical outcomes improved after 36 cases, and the learning curve seemingly did not have an obvious impact on long-term oncologic outcomes.

Robot-Assisted Total Mesorectal Excision Versus Laparoscopic Total Mesorectal Excision: A Retrospective Propensity Score-Matched Cohort Analysis in Experienced Centers

BACKGROUND

The superiority of robot-assisted over laparoscopic total mesorectal excision has not been proven. Most studies do not consider the learning curve while comparing the surgical technique.

OBJECTIVE

This study aims to compare laparoscopic with robot-assisted total mesorectal excision performed by surgeons who completed the learning curve of the technique.

DESIGN

This is a multicenter retrospective propensity score-matched analysis.

SETTINGS

The study was performed in 2 large, dedicated robot-assisted hospitals and 5 large, dedicated laparoscopic hospitals.

PATIENTS

Patients were included if they underwent a robot-assisted or laparoscopic total mesorectal excision for rectal cancer with curative intent at a dedicated center for the minimally invasive technique between January 1, 2015, and December 31, 2017.

INTERVENTIONS

We compared robot-assisted with laparoscopic total mesorectal excision.

MAIN OUTCOME MEASURES

The main outcome was conversion to laparotomy during surgery. Secondary outcomes were postoperative morbidity and positive circumferential resection margin.

RESULTS

A total of 884 patients were included and, after matching, 315 patients per treatment group remained. Conversion was similar between laparoscopic and robot-assisted total mesorectal excision (4.4% vs 2.5% (p = 0.20)). Positive circumferential resection margin was equal (3.2% vs 4.4% (p = 0.41)). Overall morbidity was comparable as well, although a lower rate of wound infections was observed in the robot-assisted group (5.7% vs 1.9% (p = 0.01)). More primary anastomoses were constructed in the robot-assisted group (50.8% vs 68.3% (p < 0.001)). Finally, more open procedures were performed in dedicated laparoscopic centers, with an overrepresentation of cT4N+ tumors in this group.

LIMITATIONS

This is a retrospective multicenter cohort; however, propensity score matching was applied to control for confounding by indication.

CONCLUSIONS

Robot-assisted and laparoscopic total mesorectal excision are equally safe in terms of short-term outcomes. However, with the robot-assisted approach, more primary anastomoses were constructed, and a lower wound infection rate was observed. See Video Abstract at http://links.lww.com/DCR/B677.ESCISIÓN MESORRECTAL TOTAL ASISTIDA POR ROBOT VERSUS ESCISIÓN MESORRECTAL TOTAL LAPAROSCÓPICA: UNA PUNTUACIÓN DE PROPENSIÓN RETROSPECTIVA ANÁLISIS DE COHORTES EMPAREJADAS EN CENTROS EXPERIMENTADOS.

ANTECEDENTES

No se ha demostrado la superioridad de la escisión mesorrectal total asistida por robot sobre la laparoscópica. La mayoría de los estudios no tienen en cuenta la curva de aprendizaje al comparar la técnica quirúrgica.

OBJETIVO

Este estudio tiene como objetivo comparar la escisión mesorrectal total laparoscópica con la asistida por robot realizada por cirujanos que completaron la curva de aprendizaje de la técnica.

DISEO

Este es un análisis multicéntrico retrospectivo emparejado por puntuación de propensión.

AJUSTES

El estudio se realizó en dos grandes hospitales dedicados asistidos por robots y cinco grandes hospitales laparoscópicos dedicados.

PACIENTES

Se incluyeron pacientes que se sometieron a escisión mesorrectal total asistida por robot o laparoscópica para cáncer de recto con intención curativa, en un centro dedicado a la técnica mínimamente invasiva entre el 1 de enero de 2015 y el 31 de diciembre de 2017.

INTERVENCIONES

Comparamos la escisión mesorrectal total asistida por robot con la laparoscópica.

PRINCIPALES MEDIDAS DE RESULTADO

El principal resultado fue la conversión a laparotomía durante la cirugía. Los resultados secundarios fueron la morbilidad posoperatoria y el margen circunferencial positivo.

RESULTADOS

Se incluyó a un total de 884 pacientes y, después de emparejar, quedaron 315 pacientes por grupo de tratamiento. La conversión fue similar entre la escisión mesorrectal total laparoscópica y asistida por robot (4,4% frente a 2,5% [p = 0,20]). El margen de resección circunferencial positivo fue igual (3,2% vs 4,4% [p = 0,41]). La morbilidad general también fue comparable, aunque se observó una menor tasa de infecciones de heridas en el grupo asistido por robot (5,7% frente a 1,9% [p = 0,01]). Se construyeron más anastomosis primarias en el grupo asistido por robot (50,8% frente a 68,3% [p < 0,001]). Finalmente, se realizaron procedimientos más abiertos en centros laparoscópicos dedicados, con una sobrerrepresentación de tumores cT4N + en este grupo.

LIMITACIONES

Ésta es una cohorte multicéntrica retrospectiva; sin embargo, se aplicó el emparejamiento por puntuación de propensión para controlar los factores de confusión por indicación.

CONCLUSIONES

La escisión mesorrectal total asistida por robot y laparoscópica son igualmente seguras en términos de resultados a corto plazo. Sin embargo, con el abordaje asistido por robot, se construyeron más anastomosis primarias y se observó una menor tasa de infección de la herida. Consulte Video Resumen en http://links.lww.com/DCR/B677. (Traducción-Dr. Gonzalo Hagerman).

Factors affecting the learning curve in robotic colorectal surgery

Learning related to robotic colorectal surgery can be measured by surgical process (such as time or adequacy of resection) or patient outcome (such as morbidity or quality of life). Time based metrics are the most commonly used variables to assess the learning curve because of ease of analysis. With analysis of the learning curve, there are factors which need to be considered because they may have a direct impact on operative times or may be surrogate markers of clinical effectiveness (unrelated to times). Variables which may impact on operation time include surgery case mix, hybrid technique, laparoscopic and open colorectal surgery experience, robotic surgical simulator training, technology, operating room team, and case complexity. Multidimensional analysis can address multiple indicators of surgical performance and include variables such as conversion rate, complications, oncological outcome and functional outcome. Analysis of patient outcome and/or global assessment of robotic skills may be the most reliable methods to assess the learning curve.

Learning Curve for Metastatic Liver Tumor Open Resection in Patients with Primary Colorectal Cancer: Use of the Cumulative Sum Method

Background: Liver resections have become the first-line treatment for primary and metastatic tumors and, therefore, are considered a core aspect of surgical training. This study aims to evaluate the learning curve of the extent and safety of liver resection procedures for patients with metastatic colorectal cancer. Methods: This single tertiary center retrospective analysis includes 158 consecutive cases of small liver resection (SLR) (n = 107) and major liver resection (MLR) (n = 58) procedures. A cumulative sum control chart (CUSUM) method was used to investigate the learning curve. Results: The operative time, total blood loss level, and incidence of adverse effects showed a learning curve. For SLRs, the CUSUM curve for operative time and blood loss level peaked at the 19th and 17th case, respectively, while for MLRs, these curves peaked at the 28th and 24th case, respectively. The CUSUM curve for minor adverse effects (MAEs) and severe adverse effects (SAEs) showed a downward slope after the 16th and 68th procedures in the SLRs group and after the 29th and 39th procedures in the MLRs cohort; however, it remained within the acceptable range throughout the entire study. Conclusion: SLR procedures were performed faster with less intraoperative blood loss and shorter postoperative stays than MLRs, and a higher number of completed procedures was required to gain stabilization and repeatability in the operating time and intraoperative blood loss level. In MLR procedures, the reduction of SAEs was accomplished significantly later than the stabilization of the operative time and intraoperative blood loss level.

The learning curve to attain surgical competency in robotic colorectal surgery

INTRODUCTION

The aim of the study was to assess the robotic colorectal surgery (RCS) learning curve of an experienced surgeon.

METHODS

A retrospective review of 117 consecutive patients who underwent total RCS at a single institution between October 2018 and July 2021 was performed. Patient demographics, surgery indications, operation type, intraoperative data, histopathology, morbidity and mortality, and length of stay were analysed. Cumulative summation technique (CUSUM) was used to construct a learning curve of surgeon console and total operation times (SCT and TOT).

RESULTS

There was no open conversion, positive resection margin and mortality in the study population. There were four Clavien-DIndo grade III complications and one local recurrence. The range for SCT was 18-855 min (mean 214, median 211) and TOT was 68-937 min (mean 302, median 291). The SCT CUSUM graph identified change in slope at cases 44 and 88, which divided the learning curve into three distinct phases. Patient demographics were similar through the three phases. There was proportionally more cancer cases performed in the first phase (P = 0.001). The mean SCT was significantly higher in Phase 2 when compared with Phases 1 and 3 (P = 0.03). The failure rate was similar through the three phases. There was a non-significant steady decline in LOS over the three phases, from 6.9 to 6.1 days.

CONCLUSION

Experienced colorectal surgeons can perform robotic surgery safely, even on patients with high complexity early in the learning curve. Audit of patient outcome should be an important component of learning curve assessment.

Evaluation of the learning curve for robot-assisted rectal surgery using the cumulative sum method

BACKGROUND

There is no clear evidence on the number of cases required to master the techniques required in robot-assisted surgery for different surgical fields and techniques. The purpose of this study was to clarify the learning curve of robot-assisted rectal surgery for malignant disease by surgical process.

METHOD

The study retrospectively analyzed robot-assisted rectal surgeries performed between April 2014 and July 2020 for which the operating time per process was measurable. The following learning curves were created using the cumulative sum (CUSUM) method: (1) console time required for total mesorectal excision (CUSUM tTME), (2) time from peritoneal incision to inferior mesenteric artery dissection (CUSUM tIMA), (3) time required to mobilize the descending and sigmoid colon (CUSUM tCM), and (4) time required to mobilize the rectum (CUSUM tRM). Each learning curve was classified into phases 1-3 and evaluated. A fifth learning curve was evaluated for robot-assisted lateral lymph node dissection (CUSUM tLLND).

RESULTS

This study included 149 cases. Phase 1 consisted of 32 cases for CUSUM tTME, 30 for CUSUM tIMA, 21 for CUSUM tCM, and 30 for CUSUM tRM; the respective numbers were 54, 48, 45, and 61 in phase 2 and 63, 71, 83, and 58 in phase 3. There was no significant difference in the number of cases in each phase. Lateral lymph node dissection was initiated in the 76th case where robot-assisted rectal surgery was performed. For CUSUM tLLND, there were 12 cases in phase 1, 6 in phase 2, and 7 cases in phase 3.

CONCLUSIONS

These findings suggest that the learning curve for robot-assisted rectal surgery is the same for all surgical processes. Surgeons who already have adequate experience in robot-assisted surgery may be able to acquire stable technique in a smaller number of cases when they start to learn other techniques.

Local recurrence of robot-assisted total mesorectal excision: a multicentre cohort study evaluating the initial cases

PURPOSE

Evidence regarding local recurrence rates in the initial cases after implementation of robot-assisted total mesorectal excision is limited. This study aims to describe local recurrence rates in four large Dutch centres during their initial cases.

METHODS

Four large Dutch centres started with the implementation of robot-assisted total mesorectal excision in respectively 2011, 2012, 2015, and 2016. Patients who underwent robot-assisted total mesorectal excision with curative intent in an elective setting for rectal carcinoma defined according to the sigmoid take-off were included. Overall survival, disease-free survival, systemic recurrence, and local recurrence were assessed at 3 years postoperatively. Subsequently, outcomes between the initial 10 cases, cases 11-40, and the subsequent cases per surgeon were compared using Cox regression analysis.

RESULTS

In total, 531 patients were included. Median follow-up time was 32 months (IQR: 19-50]. During the initial 10 cases, overall survival was 89.5%, disease-free survival was 73.1%, and local recurrence was 4.9%. During cases 11-40, this was 87.7%, 74.1%, and 6.6% respectively. Multivariable Cox regression did not reveal differences in local recurrence between the different case groups.

CONCLUSION

Local recurrence rate during the initial phases of implantation of robot-assisted total mesorectal procedures is low. Implementation of the robot-assisted technique can safely be performed, without additional cases of local recurrence during the initial cases, if performed by surgeons experienced in laparoscopic rectal cancer surgery.

Learning curve for robotic bedside assistance for rectal cancer: application of the cumulative sum method

BACKGROUND

This investigation assesses the learning curve for dedicated bedside assistance at a facility that recently adopted robot-assisted rectal resection.

METHODS

Data from patients with rectal cancer who underwent robotic rectal resections from September 2019 through April 2020 were retrospectively analyzed. Before starting robotic surgery, we set the rule that a console surgeon would not enter the sterile field and all of those maneuvers would be left to a dedicated physician. Docking time was analyzed using the cumulative sum (CUSUM) method to evaluate the learning curve. Different phases in the learning curve were identified according to CUSUM plot configuration. A comparison was made of phases 1 and 2 combined, and phase 3.

RESULT

The procedures were performed in 30 patients. Median docking time, console time was 13 min. A total of nine patients had histories of abdominal surgery. CUSUM analysis of docking time demonstrated 3 phases. Each docking time was longer in Phase 1 (the first 3 cases) than the average docking time over the all cases. The docking time in Phase 2 (the 9 middle cases) approximated the average time over the all cases. Phase 3 (the remaining 18 cases) showed further improvement of the docking procedure and time was reduced. A comparison of Phases 1 and 2 combined, and Phase 3, revealed that Phase 3 had a significantly higher rate of history of abdominal surgery.

CONCLUSION

Docking manipulation proficiency was achieved in approximately 10 cases without the influence of surgical difficulty.

Mitigation of the Robotic Pancreaticoduodenectomy Learning Curve through comprehensive training

BACKGROUND

There is an associated lag in achieving competency for robotic pancreaticoduodenectomy (PD), resulting in a learning curve. We hypothesize that the reported learning curve can be mitigated through a comprehensive graduated training protocol.

METHODS

All patients (n = 237) who underwent an open (n = 197, 83.1%) or robotic (n = 40, 16.9%) PD between 2015-2019 were identified at The Ohio State University. The learning curve for operative time and surgical failure (defined as conversion to open, blood transfusion, or Clavien-Dindo complication grade ≥3) was analyzed using a risk adjusted cumulative summation technique.

RESULTS

After 10 cases, operative time plateaued to a mean of 468.3 ± 96.3 minutes for robotic PD versus a mean of 332.5 ± 103.9 minutes for open PD (P < 0.001). There was no further apparent learning curve over time relative to rates of operative time or surgical failure. After propensity score-matching, patients undergoing robotic PD had a similar incidence of major complications, grade B/C postoperative pancreatic fistula, and delayed gastric emptying versus patients undergoing open PD (all P > 0.05).

CONCLUSION

Completion of a comprehensive procedure-specific robotic training protocol for PD mitigated the learning curve for this operative approach by shifting the curve into the training/simulation phase rather than the live operating phase. These data hold important implications for the future training and accreditation of surgeons embarking on robotic PD.

Initial Experience in Rectal Cancer Surgery for the Next Generation of Robotic Surgeons Trained in a Dual Console System

BACKGROUND

Robotic surgery for rectal cancer is used worldwide, with an increasing incidence of robotic surgeons. Therefore, the most appropriate educational system for next-generation robotic surgeons should be urgently established.

METHODS

We analyzed 39 patients who underwent robotic rectal surgery performed by a next-generation surgeon with limited experienced in laparoscopic rectal cancer surgery. The dual console system was used in the initial 15 cases, and we assessed short-term outcomes and the learning curve on operative time using the cumulative sum method.

RESULTS

The patients were divided into two groups: 15 cases in the early phase, and 24 cases in the late phase. The operative time and surgeon console time were significantly shorter in the late phase than the early phase (P < 0.001). Postoperative complications were more frequently observed in the early phase (P = 0.049); however, the estimated blood loss and length of hospital stay were not significantly different. In the initial 15 cases that using the dual console, the average operative time changing to the expert surgeon was 82 minutes in the first 5 cases, 19 minutes on average in the next 5 cases, and no change occurred in the last 5 cases. The learning curve peaked after 14 cases, plateaued from case number 15 to 23, and decreased in a linear fashion until the final case.

CONCLUSION

Education of a next generation surgeon using a dual console system for robotic rectal cancer surgery was performed safely.

Comparison of the operative outcomes and learning curves between laparoscopic and "Micro Hand S" robot-assisted total mesorectal excision for rectal cancer: a retrospective study

BACKGROUND

The Micro Hand S robot is a new surgical tool that has been applied to total mesorectal excision (TME) surgery for rectal cancer in our center. In this study, we compared the operative outcomes, functional outcomes and learning curves of the Micro Hand S robot-assisted TME (RTME) with laparoscopic TME (LTME).

METHODS

A total of 40 patients who underwent RTME and 65 who underwent LTME performed by a single surgeon between July 2015 and November 2018 were included in this retrospective study. Clinicopathologic characteristics, operative and functional outcomes, and learning curves were compared between the two groups. The learning curve was analyzed using the cumulative sum method and two stages (Phase 1, Phase 2) were identified and analyzed. All patients were followed up for at least 12 months.

RESULTS

The clinicopathologic characteristics of the two groups were similar. The learning curve was 17 cases for RTME and 34 cases for LTME. Compared with LTME, RTME was associated with less blood loss (148.2 vs. 195.0 ml, p = 0.022), and shorter length of hospital stay (9.5 vs. 12.2 days, p = 0.017), even during the learning period. With the accumulation of experience, the operative time decreased significantly from Phase 1 to Phase 2 (RTME, 360.6 vs. 323.5 min, p = 0.009; LTME, 338.1 vs. 301.9 min, p = 0.005), whereas other outcomes did not differ significantly.

CONCLUSIONS

Micro Hand S robot-assisted TME is safe and feasible even during the learning period, with outcomes comparable to laparoscopic surgery but superior in terms of blood loss, length of hospital stay, and learning curve. Trial registration Clinicaltrial.gov, NCT04836741, retrospectively registered on 5 April 2021.

Robotic gastrointestinal surgery: learning curve, educational programs and outcomes

The use of the robotic platform for gastrointestinal surgery was introduced nearly 20 years ago. However, significant growth and advancement has occurred primarily in the last decade. This is due to several advantages over traditional laparoscopic surgery allowing for more complex dissections and reconstructions. Several randomized controlled trials and retrospective reviews have demonstrated equivalent oncologic outcomes compared to open surgery with improved short-term outcomes. Unfortunately, there are currently no universally accepted or implemented training programs for robotic surgery and robotic surgery experience varies greatly. Additionally, several limitations to the robotic platform exist resulting in a distinct learning curve associated with various procedures. Therefore, implementation of robotic surgery requires a multidisciplinary team approach with commitment and investment from clinical faculty, operating room staff and hospital administrators. Additionally, there is a need for wider distribution of educational modules to train more surgeons and reduce the associated learning curve. This article will focus on the implementation of the robotic platform for surgery of the pancreas, stomach, liver, colon and rectum with an emphasis on the associated learning curve, educational platforms to develop proficiency and perioperative outcomes.

Learning curve of robotic distal and total gastrectomy

BACKGROUND

This study aims to assess the learning curve of robotic distal gastrectomy (RDG) and robotic total gastrectomy (RTG) for gastric cancer.

METHODS

Data on consecutive patients who underwent robotic gastrectomy for gastric cancer by five surgeons between March 2010 and August 2019 at two high-volume institutions were collected. The learning curve was determined based on the analyses of operation time and postoperative complications within 30 days. Cumulative sum analysis (CUSUM) and risk-adjusted-CUSUM (RA-CUSUM) were applied to identify the turning points (TPs).

RESULTS

A total of 899 consecutive patients were included. The mean number of patients needed to overcome the learning curve for operation time of RDG and RTG were 22 and 20, respectively. The number of patients needed to overcome the learning curve for postoperative complications after RDG and RTG were 23 and 18, respectively. The surgical outcomes in the post-TP group were better than in the pre-TP group and improved as surgeons' experience increased. Also, increased case numbers in RDG promoted the RTG learning process.

CONCLUSION

The present study demonstrated a substantial influence of surgical cumulative volume on improved surgical outcomes in robotic gastrectomy. Increased experience in RDG may help surgeons to achieve proficiency faster in RTG.

Comprehensive Learning Curve of Robotic Surgery: Discovery From a Multicenter Prospective Trial of Robotic Gastrectomy

OBJECTIVE

To evaluate the complication-based learning curve and identify learning-associated complications of robotic gastrectomy.

SUMMARY BACKGROUND DATA

With the increased popularity of robotic surgery, a sound understanding of the learning curve in the surgical outcome of robotic surgery has taken on great importance. However, a multicenter prospective study analyzing learning-associated morbidity has never been conducted in robotic gastrectomy.

METHODS

Data on 502 robotic gastrectomy cases were prospectively collected from 5 surgeons. Risk-adjusted cumulative sum analysis was applied to visualize the learning curve of robotic gastrectomy on operation time and complications.

RESULTS

Twenty-five cases, on average, were needed to overcome complications and operation time-learning curve sufficiently to gain proficiency in 3 surgeons. An additional 23 cases were needed to cross the transitional phase to progress from proficiency to mastery. The moderate complication rate (CD ≥ grade II) was 20% in phase 1 (cases 1-25), 10% in phase 2 (cases 26-65), 26.1% in phase 3 (cases 66-88), and 6.4% in phase 4 (cases 89-125) (P < 0.001). Among diverse complications, CD ≥ grade II intra-abdominal bleeding (P < 0.001) and abdominal pain (P = 0.01) were identified as major learning-associated morbidities of robotic gastrectomy. Previous experience on laparoscopic surgery and mode of training influenced progression in the learning curve.

CONCLUSIONS

This is the first study suggesting that technical immaturity substantially affects the surgical outcomes of robotic gastrectomy and that robotic gastrectomy is a complex procedure with a significant learning curve that has implications for physician training and credentialing.

Short-term outcomes of robotic-assisted versus conventional laparoscopic-assisted surgery for rectal cancer: a propensity score-matched analysis

It remains controversial whether the advantages of robotic-assisted surgery are beneficial for rectal cancer (RC). The study aimed to evaluate the short-term outcomes of robotic-assisted rectal surgery (RARS) compared with those of conventional laparoscopic-assisted rectal surgery. We retrospectively analyzed 539 consecutive patients with stage I-IV RC who had undergone elective surgery between January 2010 and December 2020, using propensity score-matched analysis. After propensity score matching, we enrolled 200 patients (n = 100 in each groups). Before matching, significant group-dependent differences were observed in terms of age (p = 0.04) and body mass index (p < 0.01). After matching, clinicopathologic outcomes were similar between the groups, but estimated operative time was longer and postoperative lymphorrhea was more frequent in the RARS group. Estimated blood loss, rate of conversion to laparotomy, and incidence of anastomotic leakage or reoperation were significantly lower in the RARS group. No surgical mortality was observed in either group. No significant differences were observed in terms of positive resection margins or number of lymph nodes harvested. RARS was safe and technically feasible, and achieved acceptable short-term outcomes. The robotic technique showed some advantages in RC surgery that require validation in further studies.

Implementation of robot-assisted total mesorectal excision by multiple surgeons in a large teaching hospital: Morbidity, long-term oncological and functional outcome

BACKGROUND

Robot-assisted total mesorectal excision (TME) might offer benefits in less morbidity, better functional and long-term outcome over laparoscopic TME.

METHODS

All consecutive patients undergoing robot-assisted TME for rectal cancer during implementation between May 2015 and December 2019 performed by five surgeons in a single centre were included. Outcomes included local recurrence rate at 3 years, conversion rate, circumferential resection margin (CRM) positivity rate, 30-day postoperative morbidity and outcomes of low anterior resection syndrome (LARS) questionnaires.

RESULTS

In 105 robot-assisted TME, local recurrence rate at 3 years was 7.4%, conversion to open surgery rate was 8.6%, CRM positivity rate was 5.7%, 73.3% had good quality specimen, postoperative morbidity rate was 47.6% and anastomotic leakage rate was 9.0%. Incidence of major LARS was 55.3%.

CONCLUSIONS

results of this study described acceptable morbidity, functional and long-term outcome during implementation of robotic TME for rectal cancer by multiple surgeons in a single centre.

Evolution of Robotic Surgery in a Colorectal Cancer Unit in India

Only a handful of institutions in the country have an established robotic surgery program. Evolution of robotic surgery in the colorectal division, from inception to recent times, is presented here. All the patients undergoing robotic colorectal surgery from the inception of the program (September 2014) to August 2019 were identified. The patient and treatment details and short-term outcomes were collected retrospectively from the prospectively maintained database. The cohort was divided into four chronological groups (group 1 being the oldest) to assess the surgical trends. There were 202 patients. Seventy-one percent were male. Mean BMI was 23.25. Low rectal tumours were most common (47%). A total of 74.3% patients received neo-adjuvant treatment. Multivisceral resection was done in 22 patients, including 4 synchronous liver resections. Average operating time for standard rectal surgery was 280 min with average blood loss of 235 ml. The mean nodal yield was 14. Circumferential resection margin positivity was 6.4%. The mean hospital stay for pelvic exenteration was significantly higher than the rest of the surgeries (except for posterior exenteration and total proctocolectomy) (p = 0.00). Clavin-Dindo grade 3 and 4 complications were seen in 10% patients. As the experience of the team increased, more complex cases were performed. Blood loss, margin positivity, nodal yield, leak rates and complications were evaluated group wise (excluding those with additional procedures) to assess the impact of experience. We did not find any significant change in the parameters studied. With increasing experience, the complexity of surgical procedures performed on da Vinci Xi platform can be increased in a systematic manner. Our short-term outcomes, i.e. nodes harvested, margin positivity, hospital stay and morbidity, are on par with world standards. However, we did not find any significant improvement in these parameters with increasing experience.

Impact of laparoscopic surgical experience on the learning curve of robotic rectal cancer surgery

BACKGROUND

Robotic surgery has advantages in terms of the ergonomic design and expectations of shortening the learning curve, which may reduce the number of patients with adverse outcomes during a surgeon's learning period. We investigated the differences in the learning curves of robotic surgery and clinical outcomes for rectal cancer among surgeons with differences in their experiences of laparoscopic rectal cancer surgery.

METHODS

Patients who underwent robotic surgery for colorectal cancer were reviewed retrospectively. Patients were divided into five groups by surgeons, and their clinical outcomes were analyzed. The learning curve of each surgeon with different volumes of laparoscopic experience was analyzed using the cumulative sum technique (CUSUM) for operation times, surgical failure (open conversion or anastomosis-related complications), and local failure (positive resection margins or local recurrence within 1 year).

RESULTS

A total of 662 patients who underwent robotic low anterior resection (LAR) for rectal cancer were included in the analysis. Number of laparoscopic LAR cases performed by surgeon A, B, C, D, and E prior to their first case of robotic surgery were 403, 40, 15, 5, and 0 cases, respectively. Based on CUSUM for operation time, surgeon A, B, C, D, and E's learning curve periods were 110, 39, 114, 55, and 23 cases, respectively. There were no significant differences in the surgical and oncological outcomes after robotic LAR among the surgeons.

CONCLUSIONS

This study demonstrated the limited impact of laparoscopic surgical experience on the learning curve of robotic rectal cancer surgery, which was greater than previously reported curves.

Safety and Feasibility of Robotic Natural Orifice Specimen Extraction Surgery in Colorectal Neoplasms During the Initial Learning Curve

Aim: To analyze the learning curve (LC) for robotic natural orifice specimen extraction surgery (NOSES) for colorectal neoplasms and evaluate safety and feasibility during the initial LC.

Method: Patients who consecutively underwent robotic NOSES performed by two surgeons between March 2016 and October 2019 were analyzed retrospectively. The operation time was evaluated using the cumulative sum method to analyze the LC. The clinicopathological data before and after the completion of LC were extracted and compared to evaluate safety and feasibility.

Results: In total, 99 and 66 cases were scheduled for robotic NOSES by Prof. Yao and Prof. Li, respectively. The peak points of LC were observed at the 42nd and 15th cases of Yao and Li, respectively, then operation time began to decrease. Only the operation time for Yao before the completion of LC (213.3 ± 67.0 min) was longer than that after the completion of LC (143.8 ± 33.3 min). For Yao nor for Li, other indices, such as postoperative hospital stay, intraoperative blood loss, conversion to laparotomy, incidence of anastomotic leakage, reoperation rate, and 90-day mortality rate lacked significant statistical differences(P > 0.05). In terms of feasibility, the number of lymph nodes harvested, positive resection margin rate, and total cost before and after the completion of LC had no significant statistical difference (P > 0.05).

Conclusion: The cases before the completion of LC for robotic NOSES in colorectal neoplasms varied from 15 cases to 42 cases. Robotic NOSES is safe and feasible during the initial LC.

Impact of robotic learning curve on histopathology in rectal cancer: A pooled analysis

BACKGROUND

A beneficial impact of robotic proctectomy on circumferential resection margin (CRM) is expected due to the robot's articulating instruments in the pelvis. There are however concerns about a negative impact on the quality of total mesorectal excision (TME) due to the lack of tactile feedback. The aim of this study was to assess whether surgeons' learning curve impacted CRM and TME quality.

METHODS

In a multicenter study, individual patient data of robotic proctectomy for resectable rectal cancer were pooled. Patients were stratified into two phases of surgeons' learning curve. Cumulative sum (CUSUM) analysis was used to determine the transition from learning phase (LP) to plateau phase (PP), which were compared. CRM was microscopically measured in mm by pathologists. TME quality was classified by pathologists as complete, nearly complete or incomplete. T-test and Chi-squared tests were used to compare continuous and categorical variables, respectively.

RESULTS

235 patients underwent robotic proctectomy by five surgeons. 83 LP patients were comparable to 152 PP patients for age (p = 0.20), gender (67.5% vs. 65.1% males; p = 0.72), BMI (p = 0.82), cancer stage (p = 0.36), neoadjuvant chemoradiation (p = 0.13), distance of tumor from anal verge (5.8 ± 4.4 vs. 5.5 ± 3.3; p = 0.56). CRM did not differ (7.7 ± 11.4 mm vs. 8.4 ± 10.3 mm; p = 0.62). The rate of complete TME quality was significantly improved in PP patients as compared to LP patients (73.5% vs. 92.1%; p < 0.001).

CONCLUSION

While learning had no impact on circumferential resection margins, the quality of TME significantly improved during surgeons' plateau phase as compared to their learning phase.

Learning curve in robotic colorectal surgery

With the rapid adoption of robotics in colorectal surgery, there has been growing interest in the pace at which surgeons gain competency, as it may aid in self-assessment or credentialing. Therefore, we sought to evaluate the learning curve of an expert laparoscopic colorectal surgeon who performed a variety of colorectal procedures robotically. This is a retrospective review of a prospective database of 111 subsequent colorectal procedures performed by a single colorectal surgeon. The cumulative summation technique (CUSUM) was used to construct a learning curve for robotic proficiency by analyzing total operative and console times. Postoperative outcomes including length of stay, 30-day complications, and 30-day readmission rates were evaluated. Chi-square and one-way ANOVA (including Kruskal-Wallis) tests were used to evaluate categorical and continuous variables. Our patient cohort had a mean age of 62.4, mean BMI of 26.9, and mean ASA score of 2.41. There were two conversions to open surgery. The CUSUM graph for console time indicated an initial decrease at case 13 and another decrease at case 83, generating 3 distinct performance phases: learning (n = 13), competence (n = 70), and mastery (n = 28). An interphase comparison revealed no significant differences in age, gender, BMI, ASA score, types of procedures, or indications for surgery between the three phases. Over the course of the study, both mean surgeon console time and median length of stay decreased significantly (p = 0.00017 and p = 0.016, respectively). Although statistically insignificant, there was a downward trend in total operative time and postoperative complication rates. Learning curves for robotic colorectal surgery are commonly divided into three performance phases. Our findings contribute to the construction of a reliable learning curve for the transition of colorectal surgeons to robotics. Furthermore, they may help guide the stepwise training and credentialing of new robotic surgeons.