Repair of transversely incised abdominal wall fascia in a rabbit model

OBJECTIVE: To compare several commonly used methods of closing transversely incised anterior abdominal wall in order to determine which technique results in the strongest incisional tensile strength. METHODS: Thirty-six rabbits were randomized to receive either interrupted or continuous closure with 0-Vicryl. Within these groups, each animal was randomized to one of three different bite and interval techniques: 1-cm bites/0.5-cm intervals, 1-cm bites/1-cm intervals, and 2-cm bites/1-cm intervals. Each rabbit received three to four transverse abdominal wall incisions of approximately 3-8 cm in length. The incisions were excised en bloc and stored at -70C at postoperative week 1, 2, or 4 in a random fashion. Representative 1-cm strips were harvested from each incision after thawing. The Instron tensiometer was used to determine the maximum intrinsic tensile strength required to disrupt each tissue strip at the incision. Statistical analysis was performed using analysis of variance, two-sample t test, Scheffe multiple comparison, and Kruskal-Wallis test. RESULTS: Two hundred thirty-seven strips were analyzed. The mean maximum tensile strength of all of the interrupted and continuous suture repairs was 48 and 38 lb, respectively (P < .001). The maximum tensile strength for interrupted closures was achieved at week 1 and was similar at week 4. The continuous closure was weakest at week 1 and increased to a maximum value during week 4. There was no difference in maximum tensile strength between the interrupted and continuous closure groups at week 4. There was no significant difference in the maximum tensile strength of the three repair techniques. The mean maximum tensile strength of all specimens was significantly less among those harvested during weeks 1 and 2 compared with week 4 (P = .001). CONCLUSION: In this randomized study, the interrupted closure had a greater maximum tensile strength than the continuous closure in repair of transverse incisions during the first 2 postoperative weeks. Both repair methods were associated with a similar maximum tensile strength at 4 postoperative weeks. Repair techniques using different bite sizes and intervals resulted in similar maximum tensile strengths.