Impact of Surgical Approach on Surgical Resection Quality in Mid- and Low Rectal Cancer, A Bayesian Network Meta-Analysis

Robotic intersphincteric resection for low rectal cancer: a cumulative sum analysis for the learning curve

PURPOSE

This study aimed to assess the learning curve of robot-assisted intersphincteric resection for low rectal cancer.

METHODS

We retrospectively analyzed the clinical data of 89 patients who underwent robot-assisted intersphincteric resection. All surgeries were performed by the same group of surgeons at our institution between June 2016 and April 2021. The learning curve was evaluated using a cumulative sum analysis and the best-fit curve. The different stages of the learning curve were compared based on patient characteristics and short-term clinical outcomes to evaluate their impact on clinical efficacy.

RESULTS

The minimum number of cases required to overcome the learning curve was 47. The learning curve was divided into the learning improvement and proficiency stages. Significant differences were observed in the operation time and the number of lymph nodes between the two stages (P < 0.05), whereas no significant differences were found in intraoperative blood loss, first postoperative exhaust time, postoperative complications, 3-year progression-free survival, overall survival, and local recurrence-free survival (P > 0.05).

CONCLUSION

Robotic-assisted intersphincteric resection for low rectal cancer exhibits a learning curve that can be divided into two stages: namely, learning improvement and proficiency. Achieving proficiency requires a minimum of 47 surgical cases.

Robotic-Assisted Surgery for Rectal Cancer: An Expedited Summary of the Clinical Evidence

Background

Rectal cancer is a disease in which cancer cells form in the rectum, which has the primary function of temporarily storing feces, controlling defecation, and maintaining continence. Surgery is the most common treatment for rectal cancer; surgical approaches include open, laparoscopic, and robotic assisted. We conducted an expedited summary of the clinical evidence for robotic-assisted surgery for rectal cancer, which included an evaluation of effectiveness and safety.

Methods

We performed a systematic literature search of the clinical evidence to retrieve systematic reviews and randomized controlled trials (RCTs). We assessed the risk of bias in the included systematic reviews using AMSTAR 2 (A Measurement Tool to Assess Systematic Reviews, version 2), and we assessed the risk of bias in the included RCT using the Cochrane Risk-of-Bias Tool for Randomized Trials, version 1. We reported the quality of the body of evidence as evaluated in the included systematic reviews according to the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) Working Group criteria if it was evaluated.

Results

We included 14 studies in the clinical evidence review (12 systematic reviews and 1 RCT on robotic-assisted vs. laparoscopic rectal cancer surgery and 1 systematic review on robotic-assisted vs. open rectal cancer surgery). Compared with laparoscopic rectal cancer surgery, robotic-assisted rectal cancer surgery may result in similar overall survival; similar rates of conversion, blood transfusion, and readmission,· reduced blood loss; shorter length of stay; and improved quality of life. Compared with open rectal cancer surgery, robotic-assisted rectal cancer surgery may result in similar overall survival, reduced blood loss, and shorter length of stay.

Conclusions

Robotic-assisted rectal cancer surgery may result in similar or improved clinical outcomes compared with laparoscopic and open rectal cancer surgery.

Laparoscopic intersphincteric resection vs. transanal total mesorectal excision in overweight patients with low rectal cancer

Objective

Anus-preserving surgery in overweight patients with low rectal cancer has been a challenge due to the narrow operating space. Intersphincteric resection (ISR) was once a standard therapeutic option for low rectal cancer. The effectiveness of transanal total mesorectal excision (taTME) in treating this group of patients remains uncertain as a new surgical strategy. The aim of this study was to evaluate the short-term effects of taTME with ISR in overweight patients with low rectal cancer.

Methods

A total of 53 patients with low rectal cancer were treated with taTME in 31 cases and ISR in 22 cases. The surgery-related data, pathological manifestations of surgical specimens, postoperative recovery, and postoperative complications were compared.

Results

Patients in both groups completed the surgery successfully. There were no significant differences in operative time, blood loss, anastomotic distance from the anal verge and ileostomy between the two groups (P > 0.05). TaTME group performed or virtually finished resection of the rectal mesentery, and no positive cases of Circumferential Resection Margin (CRM) or Distal Resection Margin (DRM) were detected in either group. The number of lymph nodes found in surgical specimens did not change significantly between the two groups (P = 0.391). In the subgroup analysis, however, more lymph nodes were detected in female patients undergoing taTME than in male patients (P = 0.028). The ISR group took less time to remove the drainage tubes (P = 0.013) and the same results were obtained in both groups of male patients in the subgroup analysis (P = 0.011). There were no statistically significant differences in time to start liquid diet, time to remove catheters, time to start flatus, time to begin ambulation, postoperative hospital stay, and readmission within 30 days after surgery between the two groups (P > 0.05). However, female patients in the taTME group were initiated ambulation earlier than males in the subgroup analysis (P = 0.034). The difference was insignificant in the occurrence of postoperative complications between the two groups (P > 0.05).

Conclusion

taTME is safe and feasible for the treatment of overweight patients with low rectal cancer.

The endorectal incision level of transanal total mesorectal excision (taTME): An emphasis on the distance from the anterior vs. posterior mesorectal ends to the anal verge

BACKGROUND

There is no intraluminal guidance to ensure complete inclusion of the mesorectum in transanal total mesorectal excision (taTME). This study aimed to assess the distance difference between the anterior and posterior mesorectal terminal ends and the anal verge as a potential risk for residual mesorectum after resection.

METHODS

Forty-four surgical specimens of extra-levator abdominoperineal excision (ELAPE) and 28 mid-sagittal cadaveric specimens were included to this study. The distance between the mesorectum terminal end (T) and the endoluminal landmarks (dentate line (D)/anal verge (A)) was measured and compared between men and women. Furthermore, 66 MRI images from The Cancer Imaging Archive (TCIA) were used to validate the same concept in a non-Asian population.

RESULTS

The mesorectal terminal end was found to be aligned along with the levator hiatus. From the midsagittal view, the ELAPE specimens showed that the distance between T and A anteriorly was significantly longer than the same distance posteriorly (34.74±7.79mm vs 23.74±4.24mm, P<0.001). Similarly, the distance measured in the cadaveric specimens was significantly longer anteriorly than posteriorly (P<0.001). The validation cohort of non-Asian MRI image has confirmed the same (56.68±14.17mm vs. 38.18 ±10.42mm, P<0.001(. There was no significant difference between men and women.

CONCLUSIONS

Because of the remarkable distance difference between the anterior and posterior mesorectal terminal ends away from the anal verge, the taTME proctectomy level may not meet the required mesorectal end. Thus, if TME is planned, aligning the proctectomy level around the levator hiatus would be the best place that can ensure complete TME.