Single-incision versus conventional laparoscopic surgery for rectal cancer: a meta-analysis of clinical and pathological outcomes

Introduction
Single-incision laparoscopic surgery (SILS) for rectal cancer is technically challenging. There is a lack of high-level evidence for the feasibility and safety of SILS for rectal cancer.

Aim
To compare clinical and pathological outcomes of SILS versus conventional laparoscopic surgery (CLS) for rectal cancer.

Material and methods
The PubMed, Embase, CENTRAL, and Web of Science databases were searched systematically up to November 2021. Eligibility criteria included randomized controlled trials and non-randomized clinical trials that compared the outcomes of SILS and CLS for rectal cancer. Outcomes of interest included operative, postoperative, and pathologic outcomes.

Results
Meta-analysis was performed on 6 studies involving 417 patients. In total 181 patients underwent SILS and 236 underwent CLS. SILS had better outcomes for the incision length (MD = –49.58, 95% CI: –72.43 to –26.73), postoperative pain (visual analogue scale on postoperative day 1, MD = –0.96, 95% CI: –1.18 to –0.74; postoperative day 2, MD = –1.43, 95% CI: –2.29 to –0.57), and hospital stay (MD = –1.17, 95% CI: –1.84 to –0.50). Operative outcomes, including operation time, blood loss, conversion to laparotomy, and ileostomy rate, were similar. Perioperative mortality, overall complications, reoperation, and readmission were similar. Numbers of harvested lymph nodes, lengths of proximal and distal margin, circumferential resection margin involvements, incomplete mesorectal grade, and R0 resection rates were similar.

Conclusions
SILS for rectal cancer presented superior outcomes for incision length, postoperative pain, and hospital stays. Perioperative mortality, morbidity, and pathologic outcomes of SILS were comparable to CLS. Future studies are required to determine the long-term oncologic outcomes of SILS for rectal cancer.