Robotic versus Laparoscopic Intersphincteric Resection for Low Rectal Cancer: A Comparative Study of Short-term Outcomes

Risk factors for local recurrence and long term survival after minimally invasive intersphincteric resection for very low rectal cancer: Multivariate analysis in 161 patients

INTRODUCTION

Intersphincteric resection (ISR) is the ultimate anal-sparing technique as an alternative to abdominoperineal resection in selected patients. Oncological safety is still debated. This study analyses long-term oncological results and evaluates risk factors for local recurrence (LR) and overall survival (OS) after minimally-invasive ISR.

MATERIALS AND METHODS

Retrospective single-center data were collected from a prospectively maintained colorectal database. A total of 161 patients underwent ISR between 2008 and 2018. OS and local recurrence-free survival (LRFS) were assessed using Kaplan-Meier analysis (log-rank test). Risk factors for OS and LRFS were assessed with Cox-regression analysis.

RESULTS

Median follow-up was 55 months. LR occurred in 18 patients. OS and LRFS rates at 1, 3, and 5 years were 96%, 91%, and 80% and 96%, 89%, and 87%, respectively. Tumor size (p = 0.035) and clinical T-stage (p = 0.029) were risk factors for LRFS on univariate analysis. On multivariate analysis, tumor size (HR 2.546 (95% CI: 0.976-6.637); p = 0.056) and clinical T-stage (HR 3.296 (95% CI: 0.941-11.549); p = 0.062) were not significant. Preoperative CEA (p < 0.001), pathological T-stage (p = 0.033), pathological N-stage (p = 0.016) and adjuvant treatment (p = 0.008) were prognostic factors for OS on univariate analysis. Preoperative CEA (HR 4.453 (95% CI: 2.015-9.838); p < 0.001) was a prognostic factor on multivariate analysis.

CONCLUSIONS

This study confirms the oncological safety of minimally-invasive ISR for locally advanced low-lying rectal tumors when performed in experienced centers. Despite not a risk factor for LR, tumor size and, locally advanced T-stage with anterior involvement should be carefully evaluated for optimal surgical strategy. Preoperative CEA is a prognostic factor for OS.

Difference in surgical outcomes of rectal cancer by study design: meta-analyses of randomized clinical trials, case-matched studies, and cohort studies

Background

RCTs are considered the standard in surgical research, whereas case-matched studies and propensity score matching studies are conducted as an alternative option. Both study designs have been used to investigate the potential superiority of robotic surgery over laparoscopic surgery for rectal cancer. However, no conclusion has been reached regarding whether there are differences in findings according to study design. This study aimed to examine similarities and differences in findings relating to robotic surgery for rectal cancer by study design.

Methods

A comprehensive literature search was conducted using PubMed, Scopus, and Cochrane CENTRAL to identify RCTs, case-matched studies, and cohort studies that compared robotic versus laparoscopic surgery for rectal cancer. Primary outcomes were incidence of postoperative overall complications, incidence of anastomotic leakage, and postoperative mortality. Meta-analyses were performed for each study design using a random-effects model.

Results

Fifty-nine articles were identified and reviewed. No differences were observed in incidence of anastomotic leakage, mortality, rate of positive circumferential resection margins, conversion rate, and duration of operation by study design. With respect to the incidence of postoperative overall complications and duration of hospital stay, the superiority of robotic surgery was most evident in cohort studies (risk ratio (RR) 0.83, 95 per cent c.i. 0.74 to 0.92, P < 0.001; mean difference (MD) –1.11 (95 per cent c.i. –1.86 to –0.36) days, P = 0.004; respectively), and least evident in RCTs (RR 1.12, 0.91 to 1.38, P = 0.27; MD –0.28 (–1.44 to 0.88) days, P = 0.64; respectively).

Conclusion

Results of case-matched studies were often similar to those of RCTs in terms of outcomes of robotic surgery for rectal cancer. However, case-matched studies occasionally overestimated the effects of interventions compared with RCTs.

The severity of postoperative complications after robotic versus laparoscopic surgery for rectal cancer: A systematic review, meta-analysis and meta-regression

Objective

Robotic surgery (RS) has been increasingly used for the resection of rectal cancer, and its advantages over laparoscopic surgery (LS) have been demonstrated. However, few studies focused on the severity of postoperative complications. This study aimed to compared the postoperative complications within 30 days after RS over LS according to the Clavien-Dindo (C-D) classification.

Methods

A literature research of PubMed, Embase, Cochrane Library and Web of Science were systematically performed. The studies comparing the complications of RS and LS for rectal cancer based on the C-D classification were enrolled. Primary outcomes were C-D grade III, IV, V, III-V (severe complications).

Results

Seventeen studies (3193 patients) were included in the final analysis: 1554 underwent RS and 1639 underwent LS. The RS group was associated with significantly lower rates of severe complications (OR = 0.69, 95% CI 0.53–0.90, P = 0.005), C-D grade IV (OR = 0.69, 95% CI 0.53–0.90, P = 0.005), and anastomotic leak (OR = 0.66, 95% CI 0.48–0.91, P = 0.01). There was no significant difference in C-D grade III, C-D grade I, II, I-II (minor complications), overall complications, bleeding, wound complications, postoperative ileus, urinary retention, readmission, reoperation between two groups.

Conclusions

Robotic surgery is safe for rectal cancer and may be an effective alternative to laparoscopic surgery, with lower rates of severe complications, C-D grade IV, and anastomotic leak. Further large randomized controlled trials are necessary to confirm this conclusion.