Can end-to-end anastomosis reduce the risks of anastomotic leak compared to side-to-end anastomosis? A comparative study of 518 consecutive patients undergoing laparoscopic total mesorectal excision for low- or mid-rectal cancer

Background After laparoscopic total mesorectal excision (TME) for low or mid-rectal cancer, we observed several cases of anastomotic leakage (AL) in patients with side-to-end anastomosis (STE). Thus, from December 2018, we routinely performed end-to-end anastomosis (ETE). The aim of this study was to assess if this new strategy changed AL and chronic pelvic sepsis rates in our department. Methods A retrospective study was conducted on all the patients who underwent a laparoscopic rectal resection with TME and sphincter-saving surgery for mid- and low-rectal adenocarcinoma from January 2006 to December 2019. A comparative study between STE and routine ETE was performed. The primary outcome was the assessment of postoperative AL rate. The secondary outcomes were: (a) overall morbidity rate; (c) severe morbidity rate defined by a Clavien-Dindo score > 3; (c) chronic leak rate. Results Five hundred eighteen patients underwent TME: STE was performed in 394 cases (76%) and ETE in 124 but for the first 66 cases only if STE was impossible (i.e., too short colon, obese patients). AL rates for STE were 57/204 (23%) after stapled colorectal anastomosis (CRA) and 34/190 (18%) after manual coloanal anastomosis (CAA). Since December 2018, routine ETE was performed in 58 cases. The AL rate for routine ETE was 3/24 (12%) for CRA, and 2/34 (6%) for CAA: thus, The AL rate dropped from 23% (91/394) after STE to 9% (5/58) after routine ETE (p = 0.0005). After a mean follow-up of 43 months (6-156), incidence of chronic AL was 68/394 (17%) after STE and 15/117 (13%) after ETE (p = 0.32). In the group of ETE with chronic AL, 11 patients (73%) spontaneously healed and stoma reversal was possible, whereas this happened in only 20 patients (29%) after STE (p = 0.0025). Conclusions ETE seems to be associated with a significantly lower rate of AL and higher rate of spontaneous healing after chronic AL than STE.