Peritoneal in Laparoscopic Ventral Hernia Repair 2

Background Laparoscopic ventral hernia repair (VHR) has become a well-established technique during the last decade. The repair is usually performed by reducing the contents in the hernia sac from the abdominal cavity and then covering the defect from the inside with a mesh, i.e. Intraperitoneal Onlay Mesh (IPOM). This means that the hernia sac is left in situ anterior to the mesh. This may, however, predispose for the development of fluid in the hernia sac, i.e. seroma. Even if the mesh prevents the intestines from protruding into the hernia sac, the patient may still be troubled by discomfort from the seroma that develops in the cavity of the previous hernia sac.

The risk of seroma development may be reduced if a the defect is closed before the mesh is applied (IPOM-Plus). Closing the defect may, however, cause tension and pain from the abdominal wall. Instead of closing the defect, the part of the peritoneum constituting the hernia sac may be used for closing the defect. In this case, the peritoneum is dissected from the edges of the hernia sac and then used as a flap that is fixated to the edges of the hernia sac on the opposite side. This reduces the size of the pseudosac and the peritoneal surface, which prevents transudation to the pseudosac.

In a previous study, we have compared closure of the hernia defect with peritoneal bridging. We found that closure of the defect increased the postoperative pain. In order to assess whether the potential benefit from preitoneal bridging in terms of reduced risk for seromas is present if the defect is not closed, we are undertaking a randomised controlled trial comparing bridging with IPOM without defect closure.

In order to evaluate whether peritoneal bridging reduces the seroma development following ventral hernia repair, we are undertaking a randomized controlled trial. Our goal is to include 50 patients in the study.

Method After obtaining written and oral consent from the patient, the randomisation is performed through a sealed envelope system. The patient is blinded to the allocation. Prior to the procedure, the patient is also requested to fill in the Ventral Hernia Pain Questionnaire (VHPQ).

The procedure is started according to the usual routines. Adhesions covering the defect are dissected to visualize the defect. If the patients is randomized to defect closure, it is sutured with continuous PDS 2-0. In case the patient is allocated to peritoneal bridging, the peritoneum is dissected beginning 2-3 cm from the edge of the defect. The sac is dissected all the way to the opposite edge of the defect. The peritoneal flap is pulled to the opposite side and fixated with Optifix. If the patient is randomized to surgery without bridging, the defect is left without closure.

The mesh is attached in the same, irrespective of randomization. Optifix with double-crown technique is used in both groups. Operation time and intraoperative complications are registered when the procedure is completed. From the day of the procedure until two days postoperatively, pain from the area of surgery is registered daily on a VAS-scale. Time to return to normal daily activities is registered.

The patient is invited to clinical follow-up three months, six months and one year after surgery. At all occasions the patient is requested to fill in VHPQ. One year after surgery, a computer tomography while straining to detect protrusion of the abdominal contents in the defect. Any protrusion seen at the computer tomography is graded according to a previously validated classification. The presence of seromas detected at the computer tomography is described according to Morales-Conde, The computer tomography images are assessed by two radiologists in order to reach consensus. The presence of seroma anterior to the defect is evaluated in terms of size (maximal diameter), localization, shape (round, oval, triangular), mean density (Hounsfield unit, HU) and the volume through three-dimensional reconstructions.