Principles of drainage

Drains are designated to evacuate intraperitoneal fluid collections. They can be used for diagnostic, prophylactic, or therapeutic purposes. In upper gastrointestinal surgery, diagnostic drains are mainly placed to assess intraperitoneal fluid collections in order to establish a diagnosis. These drains are seldom left in place and are, therefore, of minor importance. In contrast, prophylactic drains placed at the end of an operation are used frequently with two intentions: first, to prevent fluid accumulations which could be harmful (i.e., pancreatic juice or bile) or to evacuate fluid collections that can become infected and lead to the formation of intra-abdominal abscesses; second, prophylactic drains may be used to detect early postoperative complications, such as intra-abdominal bleeding or anastomotic leakage. Sometimes, fluid collections become infected and develop into abscesses; the management of these collections requires therapeutic drainage either by the percutaneous route or by reoperative surgical lavage.