Rate of Anastomotic Leakage After Rectal Anastomosis Depends on the Definition: Pelvic Abscesses are Significant

Background and Aims: The International Study Group of Rectal Cancer has proposed that a pelvic abscess in the proximity of the anastomosis is considered an anastomotic leak, whether or not its point of origin is detectable. This study describes how the inclusion of pelvic abscesses alters the leakage rate. Material and Methods: Risk factors and postoperative complications in patients with visible anastomotic leakage (direct leakage), pelvic abscesses alone in the vicinity of a visibly intact anastomosis (abscess leakage), and no leakage were retrospectively evaluated. Results: In total, 341 patients operated with anterior resections and who received an anastomosis within 15 cm as measured from the anal verge were included. A total of 37 patients (10.9%) had direct leakage, 13 (3.8%) had abscess leakage, and 291 (85.3%) had no leakage. The overall anastomotic leakage rate was 14.7% (50 patients). In accordance with the grading system outlined by International Study Group of Rectal Cancer, 7 patients (2.1%) experienced Grade A leakage, 19 (5.6%) Grade B, and 24 (7.0%) Grade C. Direct leak patients had more often a reoperation due to anastomotic complications (odds ratio = 19.7, p = 0.001), a permanent stoma (odds ratio = 28.5, p = 0.001), and a longer hospital stay than abscess leak patients (29.0 vs 15.5 days, p = 0.030). Conclusion: Abscess leakage accounted for over one-fourth of the overall leakage rate, raising the leakage rate. Direct leak patients were at a higher risk of requiring a reoperation, permanent stoma, and longer hospital stay than abscess leak patients. Abscess leak patients were at a greater risk for a urinary tract infection, wound infection, and postoperative intestinal obstruction than non-leak patients.