Predicting the risk and diminishing the consequences of anastomotic leakage after anterior resection for rectal cancer.

INTRODUCTION Anastomotic leakage is one of the most serious early complications of any intestinal anastomosis. The morbidity and mortality are high and patients may be at increased risk of cancer recurrence. In colorectal surgery the risks are particularly high following low anterior resection. Factors which increase and decrease the risks are discussed. METHODS A review of the main published risk factors for anastomotic leakage after anterior resection for rectal cancer together with the authors personal experience is reported. A review of a recent large randomized trial of a defunctioning stoma versus no stoma is outlined. RESULTS The main factor influencing anastomotic leakage is the height of the anastomosis above the anal verge with the lower the anastomosis the higher the risk. All anastomoses within 7 cm of the anal verge are at increased risk which includes all patients who have had a total mesorectal excision. Neoadjuvant therapy (in particular long course radiotherapy or chemoradiotherapy) increases the risk. Male sex, older age, smoking, alcohol in excess, short course radiotherapy, obesity, general fitness, immunosuppression have been reported in some series as increasing the risk. A temporary diverting stoma decreases the consequences of leakage and reduces the need for emergency re-operation. Anastomotic leakage is associated with an increased postoperative death rate, reoperative rates, need for a permanent stoma and possibly an increase in local recurrence and decreased cancer specific and overall survival. CONCLUSION Anastomotic leakage is a serious early complication following surgery for rectal cancer. The height of the anastomosis and neoadjuvant therapy are the main predictors of an increased risk. A diverting stoma diminishes the consequences of risk and reduces the need for emergency re-operation.