Systematic review of preoperative, intraoperative and postoperative risk factors for colorectal anastomotic leaks. BJS 2015; 102: 462-479.

Results

Of 1707 papers screened, 451 fulfilled the criteria for inclusion in the review. Significant preoperative risk factors were: male sex, American Society of Anesthesiologists fitness grade above II, renal disease, co‐morbidity and history of radiotherapy. Tumour‐related factors were: distal site, size larger than 3 cm, advanced stage, emergency surgery and metastatic disease. Adjustable risk factors were: smoking, obesity, poor nutrition, alcohol excess, immunosuppressants and bevacizumab. Intraoperative risk factors were: blood loss/transfusion and duration of surgery more than 4 h. Stomas lessen the consequences but not the prevalence of AL. In the postoperative period, CT is the most commonly used imaging tool, with or without rectal contrast, and a C‐reactive protein level exceeding 150 mg/l on day 3–5 is the most sensitive biochemical marker. A five‐level classification system for AL severity and appropriate management is presented.