Comparison of Biomechanical and Histological Outcomes of Different Suture Techniques in Rat Rectus Abdominis Muscle Repair.

Abstract

The aim of this study was to determine the strongest suture technique that retains the most muscle thickness to obtain functional outcome for Sprague-Dawley rat rectus abdominis muscle repair. We exposed the paired rectus abdominis muscle of 32 Sprague-Dawley rats on both sides (n = 64) and cut transversely. Immediate closure of the muscle was performed using one of 4 different suture methods (group A: interrupted suture, group B: horizontal mattress suture, group C: vertical mattress suture, group D: overlapping suture). After 8 weeks, the sutured muscle was dissected and cut for evaluation of tensile strength and muscle thickness. Histologic findings were evaluated using automatic quantitative component image analysis software (i-Solution) and immunohistochemical staining using CD31. P values were based on the Mann-Whitney test and Bonferroni correction. Group A showed the strongest tensile strength (P < 0.001). This group also demonstrated the greatest muscle thickness in comparison to the other groups. Differences between group A and the other groups were statistically significant (P < 0.001). Group A showed the highest ratio of muscle fibers and demonstrated the highest expression of CD31 (P < 0.05). The interrupted suture method used for muscle closure shows the greatest tensile strength and muscle thickness and is therefore a good option for suturing skeletal muscle. This finding has clinical applicability for suturing in the repair of skeletal muscle, especially for congenitally dehisced muscle repair.