Background: Many operative procedures involve suturing healthy, previously nontraumatized tissues. The present study was done to investigate the wound breaking strength and healing after suturing noninjured tissues.
Study design: A new experimental model of muscluloaponeurotic suture in the mouse is described and used to investigate the scar breaking strength, the concentration of 5-hydroxyproline, the extrusion of suture material, and the histological characteristics of the repair process. Scar quality was compared at three weeks between a group of mice in which suture was done without prior tissue injury (n = 24) and three groups of mice (n = 24 each) with prior tissue injury (tight-ischemic suture, incision, and cautery). Silk (n = 8), polyglactin 910 (n = 8), and polypropylene (n = 8) sutures were used within each group.
Results: Scars resulting from the suturing of healthy tissues had less breaking strength than those with ischemic, incised, or cauterized wound edges (507 g compared to 590, 730, and 732 g, respectively; p < 0.001) and had a lower 5-hydroxyproline concentration (5.1 ng/mg compared to 6.09, 6.77, and 7.49 ng/mg, respectively; p < 0.01). Polypropylene sutured scars had a higher breaking strength than silk (690 compared to 608 g, p < 0.01) or polyglactin 910 (690 compared to 626 g, p < 0.01). Most of the stitches were extruded from the scar independent of the suture material.
Conclusions: The quality of a scar does not seem to be as good when wound edges are healthy than when they have been previously injured.