Anastomotic leakage after low anterior resection for rectal cancer: facts, obscurity, and fiction.

The subject of anastomotic leakage after low anterior resection (LAR) for rectal cancer remains controversial. Risk factors have been discussed in several studies but the findings are often inconclusive. This review evaluates these studies and separates the known risk factors into those that are well documented, those that are obsolete, and those that require further research. We searched the Medline and PubMed databases using the keywords: "leakage," "low anterior resection," "rectal cancer," "risk factors," and their combinations. There were no language or publication year restrictions. References in published papers were also reviewed. Each risk factor was evaluated and discussed separately. The evidence suggests that low anastomoses are more prone to leakage. Other well-documented risk factors are male sex, smoking, and preoperative malnutrition. Routine mobilization of the splenic flexure and the use of a J-pouch seem to reduce the leakage rate. The effect of preoperative chemo-radiotherapy is under scrutiny. The indications for a protective stoma remain debatable. Omentoplasty, bowel preparation, the use of a drain, and tumor stage do not seem to affect the leakage rate. The type of operation (open or laparoscopic) and anastomosis (hand-sewn or stapled) is not crucial.