Anastomotic leakage and functional outcomes following total mesorectal excision with delayed and immediate colo-anal anastomosis for rectal cancer: Two single-arm phase II trials.

Background: Anastomotic leakage (AL) remains a major cause of morbidity following total mesorectal excision (TME). A diverting ileostomy reduces the risk of AL but impairs quality of life (QoL). Delayed colo-anal anastomosis (DCAA) may be an alternative to immediate colo-anal anastomosis (ICAA) without creation of a diverting ileostomy.

Study Design: Patients with T3 or N+ rectal tumours were treated with neoadjuvant chemoradiation and TME. To evaluate DCAA or ICAA with diverting ileostomy, a two multicenter single-arm phase II trials was designed. The primary endpoint was the rate of AL requiring a diverting ileostomy up to 30 days postoperatively. Secondary endpoints were 30-day postoperative complications, 1- and 2-year disease-free survival; QoL at baseline, 6 months and anorectal function measured by the low anterior resection syndrome questionnaire and Wexner score at baseline, 6 months and a late assessment at median 8 years following surgery.

Results: AL requiring diverting ileostomy occurred in one patient (2.1%; 95% confidence interval (CI) [0; 11.1]) in the DCAA group and in five patients (8.6%; 95%CI [3.2; 21.0]) in the ICAA group. Thirty-day postoperative complications occurred in 13 patients (27.1%) in the DCAA group and in 10 patients (19.2%) in the ICAA group. Short and long-term functional outcomes showed similar patterns.

Conclusion: These two single-arm phase II trials showed that DCAA has low rates of AL requiring a diverting ileostomy and acceptable long-term functional results. DCAA seems a good choice to restore bowel continuity.