Bursting strength evaluation in an experimental model of incisional hernia

Incisional hernias occur in up to 11 per cent of patients undergoing abdominal surgery. Up to 50 per cent of these patients with hernias will require repeat operative procedures. Management of these hernias have focused primarily on tensile strength of the mesh material, have not addressed currently used materials, and have not compared the strength of these repairs with each other. Forty-nine adult Sprague-Dawley rats had an incisional hernia created by removing a portion of their abdominal wall that was then repaired primarily, using either a composite mesh, Dual mesh (Gore-Tex), or polypropylene mesh. Six weeks after the repair, the rats were euthanized. Hydrostatic distension of the abdominal cavity was performed to compare bursting strength of each repair. Wound tensile strength was assessed and compared. Tissue samples were also taken to compare repair types for incorporation of prosthetic materials. The gross weight of the animals subjected to hydrostatic distention was equivalent between groups, as was the volume required prior to failure of the repair. There was a trend toward improved tensile strength of the Prolene mesh repair, which had a lower average inflammatory and fibrosis score on histology. Overall, the type of mesh used for repair does not seem to impact significantly the strength of the repair when assessed 6 weeks postoperatively. Choice of prosthetic material to repair the hernia should be made based on economics and handling characteristics alone. Prolene mesh has satisfactory strength with the least amount of inflammation and fibrosis.