Comparison of effects of suture materials on wound healing in a rabbit pyeloplasty model.

OBJECTIVES To compare the effects of chromic catgut, polyglactic acid, polydioxanone (PDS), and polytrimethylene carbonate suture on urothelial healing in a rabbit model simulating pyeloplasty. METHODS Pyeloureterotomies were performed on 8-week-old rabbits [12 rabbits (24 renal units) and 3 control rabbits] and closed with interrupted 7-0 sutures. At 10 days, 5 weeks, and 12 weeks postoperatively, we assessed the upper tracts by examining microscopic sections of the renal pelvis and upper ureter. Acute and chronic inflammation, foreign body reaction, and fibrosis/scar formation were assessed blindly and scored from 0 to 4. RESULTS Histologic evidence of acute and chronic inflammation and foreign body reaction was most severe at 10 days and 5 weeks in pyeloureterotomies closed with chromic catgut. There was mild inflammation in those closed with polyglactic acid at 10 days, but it was minimal in those closed with polyglactic acid, PDS, and polytrimethylene carbonate at 5 and 12 weeks. Reabsorption of polyglactic acid was complete by 5 weeks, but was incomplete with the other three sutures at that time. By 12 weeks, there was persistent suture in 50% of the renal units closed with polydioxanone and in 100% of those closed with polytrimethylene carbonate. No animal developed a renal calculus. CONCLUSIONS Because of the mild inflammatory response and rapid tissue reabsorption of polyglactic acid in this animal model, this suture appears to be the best suture for pyeloplasty.