Differences in polypropylene shrinkage depending on mesh position in an experimental study.

BACKGROUND: Polypropylene (PP) mesh is one of the most frequent materials used in hernia repair. We have experimentally evaluated the shrinkage of PP mesh depending on the place of implantation. METHODS: In 15 New Zealand rabbits a muscular defect measuring 3 x 3 cm was created in both pararectal sides of the abdominal wall. The defect was repaired using a PP mesh measuring 5 x 3.5 cm that was placed in the right side in the sublay location and in the left side in the onlay location. Five animals were killed on the 30th, 60th, and 90th postoperative days. Macroscopic measurement and microscopic study of the prosthesis-host tissue interfaces were performed. RESULTS: One rabbit was killed because of severe infection in the onlay mesh. Another 2 infections were tolerated in the onlay mesh side. All the prostheses were integrated in the host tissue at death. In the macroscopic evaluation the mesh areas were reduced by 25.92% on the 30th day, by 28.67% on the 60th day, and by 29.02% on the 90th day. The mesh shrinkage was greater in the onlay group than in the sublay group at the 3 time intervals. More inflammatory leukocyte and mononuclear responses also were seen in the onlay group. CONCLUSIONS: These observations support the theory of PP mesh shrinkage as a consequence of the incorporation of the biomaterial to the scarring tissue. This shrinkage is significantly more intense if the meshes are placed in the onlay position.

Prevalence and management of hernias in peritoneal dialysis patients.

OBJECTIVES: The aim of this study was to assess the prevalence of hernias before and after the start of continuous ambulatory peritoneal dialysis (CAPD) in patients with end-stage renal disease, and to evaluate the result of a proposed surgical treatment. DESIGN: Prospective observational study. SETTING: University hospital. PATIENTS: 122 patients who started CAPD from 1994 to 2000; 26 hernias were diagnosed in 21 (17.2%) patients. MAIN OUTCOME MEASURES: Finding of hernias; morbidity associated with catheter insertion and hernia repair; recurrence of hernias. RESULTS: 19 hernias were detected in 15 patients (12.3%) before they began CAPD; only 7 hernias were observed while on CAPD. Umbilical (61.5%) and inguinal (26.9%) hernias were the most common. Multiple hernias were detected in 4 patients. Simultaneous repair of hernia and catheter insertion was performed in patients with pre-existing hernias. Under local anesthesia, most patients were operated on with surgical techniques of tension-free hernioplasty using a polypropylene mesh. Only mild post-operative complications were recorded: 3 seromas and 1 hematoma. No fluid leakage was found in our series. There were no long-term complications (infection or recurrence) related to the mesh. CONCLUSIONS: 73% of hernias in peritoneal dialysis patients occur before starting dialysis. Hernia problems in these high-risk patients can be safely solved using a careful technique with application of tension-free hernioplasty. Most may be repaired under local anesthesia with simultaneous catheter insertion.