Is routine splenic flexure mobilization always necessary in laparotomic or laparoscopic anterior rectal resection? A systematic review and comprehensive meta-analysis.

Splenic flexure mobilization (SFM) is one of the most difficult steps in laparoscopic colorectal surgery and its role is harshly debated. Some surgeons considered it routinely necessary to obtain a safe anastomosis and to respect oncologic criteria; for others SFM is frequently unnecessary, not ensuring the aspects mentioned above and increasing the risk of morbidity (splenic, bowel and vessels injury, lengthened procedure). We performed a systematic review and a comprehensive meta-analysis, without any language restriction, about the peri-operative and post-operative outcomes (anastomotic leakage, intra-operative complication, conversion rate, operative time, post-operative bleeding, intra-abdominal collection, prolonged ileus, wound infection, anastomotic stricture, overall complications, hospital stay, re-operation, post-operative mortality, R0 margin resection, local recurrence) in patients undergoing elective anterior rectal resection (ARR) with or without SFM, both in laparotomic (LT) and laparoscopic (LS) approach. Fourteen studies were meta-analyzed with a total amount of 42,221 patients. The comprehensive meta-analysis shows that the mobilization or the preservation (SFP) of the splenic flexure does not statistically influence the incidence of colorectal anastomotic leakage, conversion rate, post-operative bleeding, intra-abdominal collection, prolonged ileus, wound infection, anastomotic stricture, overall complications, hospital stay, re-operation, R0 margin resection, and local recurrence results. The operative time is significantly longer in every group of patients undergoing SFM. The incidence of intra-operative complication is statistically increased in overall patients and also in the LS subgroup of patients undergoing SFM, in which also higher incidence of wound infection and re-operation is shown. The meta-analysis shows that SFM may be considered not necessary to ensure better peri-operative and post-operative outcomes in both LT and LS ARR.