Wound breaking strength and healing after suturing noninjured tissues.

Abstract

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. 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. 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. The quality of a scar does not seem to be as good when wound edges are healthy than when they have been previously injured.