[Diagnosis and definition of anastomotic leakage from the surgeon's perspective].

The leak rates of different gastrointestinal anastomoses vary considerably but despite this there are common and general concepts for diagnosis and management. Early diagnosis and timely consistent therapy must guide management to prevent harm to the patients. Diagnosis of anastomotic leaks is coupled to clinical signs of the patients and should be initiated promptly. Dependent on the localization of the leak, computed tomography with administration of oral or rectal contrast dye and endoscopy are of high diagnostic value. Both procedures guarantee the option of drainage or stenting through interventional drains or stent placement. Only the implementation of uniform definitions of anastomotic leaks enables surgeons to compare and to improve surgical treatment. Over recent years consensus definitions of postoperative complications including bile leak, pancreatic fistula and colorectal leak have been formulated. These definitions are based on a 3-fold increase of bilirubin (bile leak) or amylase levels (pancreatic fistula) in abdominal drainage fluid compared to serum levels or on an intestinal wall defect with communication of the intraluminal and extraluminal compartments (colorectal anastomosis). The definitions each describe three severity grades A-C. A change of clinical management is required in grade B whereas grade C usually requires a re-operation. Comparable consensus definitions for anastomotic leaks following esophagogastrostomy or esophagojejunostomy or following small bowel anastomosis have not been established. The authors strongly recommend implementation of the presented consensus definitions into clinical and academic daily practice.