Evaluation of progestogens for postoperative adhesion prevention

Progesterone (P) has been shown to have potent antiinflammatory and immunosuppressive properties. Previous reports have suggested that the use of P decreases postoperative adhesion formation. To further evaluate the role of pharmacologic doses of progestogens in adhesion prevention, 42 mature New Zealand White rabbits underwent standardized injuries to the uterine horns, fimbriae, and pelvic peritoneum and received one of six treatments. Group S had intraperitoneal placement of normal saline (0.9%); group H received intraperitoneal placement of 32% dextran 70; group IM-P received intramuscular P-in-oil 10 days before and after laparotomy in addition to intraperitoneal saline; group IP-P had intraperitoneal placement of an aqueous P suspension; group DP received medroxyprogesterone acetate intraperitoneally; and group C received no intramuscular or intraperitoneal adhesion-prevention agents. The animals were sacrificed 6 weeks after laparotomy, and the adhesions were scored. Intraperitoneal saline (group S) significantly reduced the amount of adhesions when compared with the control group (C) (P less than 0.05). No significant difference was observed when group S was compared with group H. Intramuscular P added to saline (group IM-P) did not cause further reduction in adhesions when compared with group S. Both group IP-P and group DP had more adhesions than did group S (P less than 0.01). These data fail to support previous claims regarding adhesion prevention by the use of locally or parenterally administered progestogens.