[Imaging diagnosis and imaging risk factors of anastomotic leakage after rectal cancer surgery].

Dispite continual improvements in diagnostic and management techniques, anastomotic leak (AL) remains one of the most devastating consequences of rectal cancer surgery. Recently, many investigations have attempted to identify the risk factors and established risk model to predict and prevent anastomotic leakage after low anterior resection. The distance between the lower edge of rectal cancer and the anal verge measured by magnetic resonance imaging was demonstrated as one of the independent risk factors associated with AL. Adequate vascular perfusion is of paramount importance for successful anastomosis and prevention of AL. Near-infrared fluorescence technology with indocyanine green has become the most promising method that allows the evaluation of intestinal perfusion intraoperatively, resulting in fewer AL. To date, three ongoing randomized controlled trials have attempted to identify the ability of near-infrared fluorescence technology in decreasing the incidence of AL after low anterior resection. Early diagnosis by using correct modalities is crucial to minimize mortality and morbidity. The diagnosis of AL will be accurate when the correct imaging modalities were selected, including contrast extravasation, computed tomography (CT), CT with contrast extravasation, and so on. In general, the assessment of anastomoses with contrast enema should be performed 6-8 weeks postoperatively to minimize radiological leaks while preventing unnecessary delay in stoma reversal. In comparison, CT with contrast enema was accurate to confirm or rule out AL shown as contrast extravasation.