The effect of suture materials on healing wounds of the bladder.

The healing pattern of bladder tissue and its response to various suture materials were studied and compared with data reported previously on skin, stomach and colon wounds. Tensile strength, biochemical data and histologic reactions were used as parameters of wound healing measurement. The healing pattern of urinary bladder wounds resembles that observed for stomach and colon. However, wounds of the urinary bladder wall regain strength equal to unwounded bladder wall within 21 days, whereas wounds of stomach and colon do not achieve more than 70 per cent of unwounded tissue strength after 120 days. The rate of collagen synthesis in bladder wounds reaches a peak at five days and returns to that of normal unwounded tissue by 70 days. Colon and stomach wounds, on the other hand, showed elevated rates of collagen synthesis even at 120 days. As with colon and stomach, absorbable sutures appear to lower the strength of both the wound and unwounded tissue. However, in stomach and colon this effect is only observed during the first 21 days of healing; in the bladder it persists throughout the 120 day observation period. No histologic evidence of smooth muscle regeneration was seen in bladder wounds. Noncollagenous protein synthesis was not increased in the wound, also suggesting smooth muscle regeneration does not occur. Silk and Mersilene sutures produced the greatest tissue reaction; if the sutures were exposed in the lumen of the bladder, stone formation was observed. This was not observed with monofilament polypropylene sutures. Plain catgut produced the least tissue reaction, but both plain aions comparable with chromic catgut but were regularly absorbed between 28 and 70 days. Since the bladder is well healed by 21 days, polyglactin-910 may be an ideal suture for use in the bladder.