Evaluation of recombinant tissue-type plasminogen activator in adhesion prevention and neoangiogenesis in a rat experimental adhesion model

This study was designed to test the effect of recombinant tissue-type plasminogen activator (rt-PA) in reducing adhesion formation and to observe its influence on peritoneal neoangiogenesis. In 20 Wistar rats, a 4-cm midline incision was made, and a square piece of Silastic, 0.5×0.5 cm and 0.2 mm thick, was fixed on the right side of the peritoneum with two separate angular stitches of nylon 9/O. The rats were randomized into two groups of 10 animals each. In the first group we injected 0.2 mg of rt-PA intraperitoneally three times a day. The second group of 10 rats was used as a control group. Each rat was reoperated on day 12. Intraperitoneal injection of rt-PA seemed not to affect adhesion formation, as a 100% adhesion rate was reported in the treated group compared with 90% of the control group. The results showed that rt-PA acts on the neoangiogenesis involved in postsurgical adhesion formation by reducing the size and length of the vessels. This action seems to slow down peritoneal healing with a negative effect on postsurgical adhesion prevention.