How to improve the uterotomy healing. I. Effects of fibrin and tumor necrosis factor-alpha in the rat uterotomy model.

Suboptimal uterotomy healing following cesarean delivery or metroplastic operations may lead to considerable complications. New insights in the biology of wound healing and the availability of a variety of biologic response modifiers open the possibility to modulate the process of wound healing in order to gain clinical benefits. Can uterotomy healing be improved by local application of biosubstances? We developed an uterotomy model in the rat and measured the bursting pressure at defined times postwounding as a functional parameter of wound healing. In addition, the healing process was assessed by serial light microscopic histology. Uterotomy healing was investigated in the presence of fibrin alone or with fibrin containing tumor necrosis factor-alpha (TNF-alpha-fibrin) compared to controls. The fibrin matrix incorporated into rat uterotomies reduced wound hemorrhage and led to a 45% increase of early (Day 3) bursting pressure (not significant). With 20 micrograms TNF-alpha in the fibrin matrix, Day 3 bursting pressure was elevated by more than 100% (P < 0.05). Histologically, inflammation and granulation tissue formation was markedly enhanced. Two micrograms of TNF-alpha/wound did not show any effect and 200 micrograms TNF-alpha even led to a decrease in early bursting strength. After 1 week, no differences in bursting pressure or wound histology could be detected between uterotomies treated with fibrin or TNF-alpha-fibrin compared to controls. The rat uterotomy model appears to be suitable for investigating new biological means to improve uterine wound healing.(ABSTRACT TRUNCATED AT 250 WORDS)