Comparison of Polypropylene Mesh and Expanded Polytetrafluoroethylene Patch for Repair of Abdominal Wall Defects in Rat

BACKGROUND: Large abdominal wall defect resulting from trauma, invasive infection, tumor resection, or other causes continue to be major problems for patients and surgeons. The lack of sufficient tissue may require the insertion of prosthetic materials. This study compares the results of PPM mesh and e-PTFE patch for repairs of abdominal wall defects. METHODS: The anterior abdominal walls of Sprague-Dawley rats, including fascia, muscle, and peritoneum were removed. The defects were repaired with a PPM mesh or an e-PTFE patch. Animals were killed at 1, 2, 6, and 12 weeks after the operation, and the implant were excised along their margins and evaluated for gross and microscopic differences. RESULTS: Histological examination showed that PPM was progressively infiltrated by whorled disorganized collagen fiber, which became densely adherent to the mesh. In contrast, the e-PTFE was infiltrated by fine fibrils of collagen, which progressively penetrated the interstices of the material, binding it firmly to the tissue. One of the most serious complications associated with fascial closure with PPM was the development of visceral adhesions. CONCLUSIONS: e-PTFE patch material has a lower foreign body reaction, a lower infectability, and a lower rate of adhesion formation than PPM mesh.

Bacteriologic Study and Prophylactic Antibiotics in the Acute and Complicated Appendicitis

This prospective study was performed to determine the effective antibiotics for use in treating acute appendicitis patients during the perioperative period. To identify the sensitive antibiotics, the peritoneal fluid was cultured during operation. Also, wound infection was defined as pus or serous discharge in the wound or when we opened the wound under suspicious of a wound problem. The results were obtained as follows: 1) A total of 138 cases treated during the two years from January 1995 to December 1996 were examined; 84 of them (60.87%) were found to have positive peritoneal fluid cultures, of which 29 (34.52%) were monomicrobial and 55 (65.48%) were polymicrobial. 2) The most common species were Escherichia coli (73.81%), Bacteroides (32.14%), Klebsiella (16.67%), Pseudomonas (9.52%), and Streptococcus (9.52%). 3) In the sensitivity test, the most sensitive drugs were aminoglycosides and cefotaxime. 4) Infectious complications, which developed in 27 (19.6%) patients, were wound infection and intraabdominal abscess. 5) The average length of stay for all patients 9.9 days (range: 3 to 32 days). 6) The common organisms curtured from the complication cases were E. coli and Bacteroides.