EXPERIMENTAL ASSAY OF A DUAL MESH(R) POLYTETRAFLUOROETHYLENE PROSTHESIS (NONPOROUS ON ONE SIDE) IN THE REPAIR OF ABDOMINAL-WALL DEFECTS

The porosity of the prosthetic biomaterials used to repair defects in the abdominal wall seems to influence the tissue repair process insofa r as tissue integration of the prosthetic material and the formation o f adhesions with abdominal viscera are concerned. We studied the behav iour of a new type of polytetrafluoroethylene prosthesis used for the repair of abdominal wall defects, Dual Mesh(R) (DM), which has two dif ferent faces; one face has a porosity between 30 and 60 mu m, while th e other is nonporous. In 20 New Zealand White rabbits, a full-thicknes s (except skin) 7 cm x 5 cm defect was created in the anterior abdomin al wall that was repaired with DM. At 14, 30, 60 and 90 days, samples were obtained and studied by light and scanning electron microscopy. A n immunohistochemical study was made with antibody anti-rabbit macroph ages (RAM-11). Tensile strength was measured with an Instron tensiomet er using 2-cm-wide strips obtained parallel to the shorter axis of the implant. DM induced little tissue adhesion to the material on the vis ceral peritoneum interface and was surrounded by organized repair tiss ue. The biomaterial was integrated in the repair tissue on the subcuta neous interface, but not on the peritoneal interface. The macrophage r esponse decreased between days 14 and 90 (P < 0.001). Tensile strength increased significantly (P < 0.05) at every study period. We conclude that the DM prosthesis has little tendency to formation of visceral a dhesions, the DM prosthesis was well tolerated by the receptor organis m and the tensile strength of the prosthesis/receptor tissue interface increased with time. (C) 1996 Elsevier Science Limited