Anastomotic leaks after intestinal anastomosis: it's later than you think.

PURPOSE: Anastomotic leaks are among the most dreaded complications after colorectal surgery. However, problems with definitions and the retrospective nature of previous analyses have been major limitations. We sought to use a prospective database to define the true incidence and presentation of anastomotic leakage after intestinal anastomosis.
METHODS: A prospective database of two colorectal surgeons was reviewed over a 10-year period (1995-2004). The incidence of leak by surgical site, timing of diagnosis, method of detection, and treatment was noted. Complications were entered prospectively by a nurse practitioner directly involved in patient care. Standardized criteria for diagnosis were used. A logistic regression model was used to discriminate statistical variation.
RESULTS: A total of 1223 patients underwent resection and anastomosis during the study period. Mean age was 59.1 years. Leaks occurred in 33 patients (2.7%). Diagnosis was made a mean of 12.7 days postoperatively, including four beyond 30 days (12.1%). There was no difference in leak rate by surgeon (3.6% vs. 2.2%; P = 0.08). The leak rate was similar by surgical site except for a markedly increased leak rate with ileorectal anastomosis (P = 0.001). Twelve leaks were diagnosed clinically versus 21 radiographically. Contrast enema correctly identified only 4 of 10 leaks, whereas CT correctly identified 17 of 19. A total of 14 of 33 (42%) patients had their leak diagnosed only after readmission. Fifteen patients required fecal diversion, whereas 18 could be managed nonoperatively.
CONCLUSIONS: Anastomotic leaks are frequently diagnosed late in the postoperative period and often after initial hospital discharge, highlighting the importance of prospective data entry and adequate follow-up. CT scan is the preferred diagnostic modality when imaging is required. More than half of leaks can be managed without fecal diversion.