Biomechanics of the front abdominal wall as a potential factor leading to recurrence with laparoscopic ventral hernia repair.

Background: Intraabdominal pressure often is blamed as the cause of mesh-fascia junction failure after laparoscopic ventral hernia repair. Stretching of the mesh during a cough or defecation may lead to recurrence. Little is known about the movements of mesh in the abdominal cavity after this operation. This study investigated the front abdominal wall to describe its elasticity in vivo and searched for elongations that possibly stretched an implanted mesh, thereby causing fixation failure and subsequent recurrence.

Methods: To measure front abdominal wall elongations, a model of fascia movements was created. Eight healthy volunteers were measured during exercise to determine the extent of elongations in their front abdominal wall. Videos were analyzed in three positions to create a mathematical shell structure. A computerized model based on the net movement of nodes was calculated to determine the axes and values for maximum elongations.

Results: The largest average elongations were measured for the upper midline (32.08%) and the transverse line in the low lateral area (34.06%). The maximum values for these lines were larger than 100% for the middle line (133.78%) and exceeded 50% for the entire middle line. The values for the horizontal lines did not reach 10% at any level. According to these data, areas of both high and low elasticity were defined.

Conclusions: The presented experiment adds new parameters to the understanding of in vivo mesh behavior. Elongation of the front abdominal wall may stretch implanted mesh and could be a cause of recurrence in cases of insufficient fixation.