Dose dependency and wound healing aspects of the use of tissue plasminogen activator in the prevention of intra-abdominal adhesions.

Intra-abdominal adhesions have been shown to result from the impairment of peritoneal fibrinolysis by inhibitors present in ischemic tissue. A reproducible model for the formation of intra-abdominal adhesions was utilized for the evaluation of the effectiveness of intraperitoneal applications of recombinant tissue plasminogen activator (rtPA) in adhesion prevention. Concentrations of rtPA required to overcome the inhibition of fibrinolysis in this model were estimated by titration of that amount of rtPA required to lyse blood clot in the presence of a measured amount of ischemic tissue. Adhesions were graded, and the hydroxyproline content of the abdominal wounds was analyzed. The effect of intraperitoneal administration of rtPA on adhesion formation was strongly dose related. Levels of rtPA of 0.01 mg/mL showed no effect (p < 0.75) on adhesion formation, whereas levels of 0.1 mg/mL either prevented or significantly modified the formation of intra-abdominal adhesions (p < 0.05). Concomitantly, wound hydroxyproline content was significantly reduced (p = 0.004). Prior investigations have shown a strong correlation between wound bursting strength and hydroxyproline content. The results of this study indicated that the levels of rtPA required to alter or prevent intra-abdominal adhesion formation also produce a significant impairment of the early phase of wound healing as measured by the wound content of hydroxyproline.