Effect of Kono-S anastomosis on reducing postoperative recurrence rates in Crohn's disease: a systematic review and meta-analysis

Background Kono-S anastomosis has gained increasing interest although evaluation of its impact on reducing Crohn's recurrence shows conflicting results. This study aimed to evaluate the short- and long-term outcomes for patients with Crohn's disease requiring surgery with Kono-S compared to conventional anastomosis. Methods A systematic review and meta-analysis included patients with Crohn's disease treated with bowel resection and Kono-S anastomosis reconstruction versus a comparator arm of conventional anastomosis technique. Recurrence outcomes examined were endoscopic recurrence rates, mean postoperative Rutgeerts score, surgical recurrence, clinical recurrence, and postoperative biologics use. Short-term postoperative outcomes include anastomotic leaks, surgical site infection, postoperative ileus, and mean operative time. Results A total of 873 studies were identified with 15 remaining after abstract review encompassing 1501 patients, 765 with Kono-S and 736 with conventional anastomosis. Recurrence was significantly lower in the Kono-S arm, with endoscopic recurrence rates of 41% vs 48% (RR 0.86, 95% CI 0.73-1.00, p = 0.05) and surgical recurrence rates of 2.7% vs 21.0% (RR 0.13, 95% CI 0.06-0.30, p < 0.001). There was a significantly lower anastomotic leak rate in the Kono-S arm when compared to conventional anastomosis, 1.7% vs 4.9% (RR 0.37, 95% CI 0.19-0.74, p = 0.005). Mean operative time was similar between both groups. Conclusions Kono-S is a safe and feasible anastomotic technique with lower rates of endoscopic and surgical postoperative recurrence. While we await further trials to substantiate this benefit, Kono-S anastomosis should be considered as an important tool in the armamentarium of a surgeon in anastomotic construction to reduce recurrence.