Background The major challenge in the management of patients with an infected open abdomen (OA) is to control septic peritonitis and intra-abdominal fluid secretion, and to facilitate repeated abdominal exploration, while preserving the fascia for delayed primary closure. We here present a novel method for closure of the infected OA, based on continuous dynamic tension, in order to achieve re-approximation of the fascial edges of the abdominal wall. Methods Eighteen cases with severe peritonitis of various origin (e.g., gastrointestinal perforations, anastomotic leakage) were primarily stabilized by laparostomy, sealed with either the vacuum-assisted closure abdominal dressing or the Bogota bag. After hemodynamic stabilization and control of the sepsis, the Abdominal Re-approximation Anchor System (ABRA; Canica Design, Almonte, Ontario, Canada) was applied. This system approximates the wound margins through dynamic traction exerted by transfascial elastomers. Before ABRA application, 5/18 patients had a grade 2B, 2/18 a grade 3, and 11/18 a grade or 4 status according to the open abdomen classification of Bjorck. Results In this severely ill population the mean time before ABRA system application was 12 days (range: 2-39 days). Two of 18 patients died of non-ABRA-related causes within three weeks. In 14 of the remaining 16 patients (88%) primary abdominal closure of the midline was accomplished in 15 days (range: 7-30 days). The other two patients needed a component separation technique according to Ramirez to reach closure. However, secondary wound dehiscence occurred in both these patients. Two thirds of patients (12/18) developed pressure sores to the skin and/or dermis, but all healed without further complications. During outpatient clinic follow-up, 4/14 successfully closed patients still developed a midline hernia. Conclusions Delayed primary closure of OA in septic patients could be achieved in 88% with this new approximation system. However, the risk of hernia development remained. We consider this system a useful tool in the treatment of septic patients with an open abdomen.