[Polypropylene and polydioxanone show similar biomechanical efficacy in midline closure].

INTRODUCTION: After laparotomy, the incidence of incisional hernia is high, especially when the abdomen in opened along the linea alba, a weak structure of the abdominal wall. This study was designed to evaluate the biomechanical resistance of midline closure using the same surgical technique but two different types of suture material, a long-lasting absorbable material and a non-absorbable material.

MATERIAL AND METHODS: A 7.5 cm midline laparotomy was performed in 48 New Zealand White rabbits. The surgical wound was then repaired with an en masse running suture using polypropylene 4/0 or polydioxanone 4/0. Animals not subjected to surgery were used as controls. Morphological, immunohistochemical and biomechanical tests were undertaken 3 weeks, 6 weeks and 6 months after surgery.

RESULTS: Both types of suture gave rise to scar tissue composed of collagen fibers concentrically arranged around the suture filaments. Six months after surgery, the polydioxanone suture had almost completely degraded. The macrophage response steadily diminished over time, although it was significantly greater in wounds closed by polydioxanone suture. No significant differences were found in the biomechanical strength provided by the two types of suture.

CONCLUSIONS: After laparotomy closure at the linea alba, both suture materials showed optimal biological behavior. The composition of the suture material did not affect the tensile strength of the repair zone.