Interparietal hernias after open retromuscular hernia repair.

The retromuscular or sublay repair of ventral hernias, popularized by Rives and Stoppa, requires that a layer of tissue be reapproximated dorsal to the mesh to separate the bowel from the prosthetic. This is the first report of two patients who developed bowel obstruction resulting from interparietal incarceration between the posterior rectus sheath and the prosthetic graft through a defect in this dorsal layer. Both patients underwent open retromuscular hernia repair, one with lightweight polypropylene mesh, the other with human acellular dermal matrix. Postoperatively (day 3 and day 42, respectively), the patients developed signs of bowel obstruction. Computed tomography demonstrated the herniation of the small bowel into the potential space between the prosthesis and the posterior rectus sheath. The first patient underwent successful laparoscopic repair, while the second patient had an open operation to reduce the incarcerated bowel and repair the defect. In the patient convalescing from an uneventful retromuscular hernia repair who develops signs and symptoms of a bowel obstruction, there should be a high index of suspicion that an interparietal hernia may have formed, with the small bowel herniated into the surgically created space between the prosthetic and the posterior rectus sheath.