Abdominal negative pressure therapy is a procedure for treating patients with an open abdomen (laparostoma) where closure of the abdominal wall is not or no longer possible or advisable. Classic indications include abdominal sepsis and abdominal compartment syndrome.
The mechanism of abdominal negative pressure therapy is based on the principles of occlusion and negative pressure therapy. Occlusion means the abdominal cavity is sealed airtight and watertight with a special film dressing, allowing the connection of a pump that creates negative pressure in the abdomen through continuous or intermittent suction. The negative pressure leads to the removal of exudate and debris from the peritoneal cavity (drainage effect) and to a provisional, suture-free dynamic abdominal wall closure. Abdominal negative pressure therapy is generally referred to as "vacuum therapy," which is not physically correct since only negative pressure and not a vacuum is created [1].
The idea of treating the open abdomen with negative pressure therapy is based on the principle of negative pressure therapy for superficial wounds, which is used with great success in acute and chronic wounds. Negative pressure therapy is contraindicated in patients with clinically relevant coagulation disorders, untreated osteomyelitis or malignant wounds, and exposed organs and blood vessels. Therefore, negative pressure therapy in its usual application form for acute and chronic wounds should not be used in the abdomen, as the negative pressure combined with occlusive dressings poses a high risk for the development of small bowel fistulas. Accordingly, the application of negative pressure therapy in the abdomen requires special occlusive dressings with suitable films, foams, and gauzes [2, 3, 4].
The open abdomen is traditionally associated with poor outcomes and significant mortality and morbidity for patients. Local negative pressure therapy offers significant advantages over traditional dressings and interventional measures:
1. Abdominal negative pressure therapy reduces the risk of abdominal compartment syndrome because the dressing stabilizes the abdominal wall without traditional sutures [5].
2. Negative pressure therapy increases the chances for a (later) primary closure of the abdominal cavity, avoiding complex reconstructive measures for abdominal wall closure.
3. Negative pressure therapy allows for prone positioning to improve breathing because the system stabilizes the abdominal wall, which is necessary for diaphragm-assisted breathing. This, in turn, enables earlier extubation.
4. Compared to conventional therapy for the open abdomen (e.g., placement of moist abdominal towels or waterproof film), negative pressure therapy reduces mortality [6].
5. In "fit" patients, portable negative pressure systems allow for early mobilization and transfer to a peripheral ward.