USE OF MEDROXYPROGESTERONE ACETATE IN THE PREVENTION OF POSTOPERATIVEADHESIONS

Objectives: To evaluate the efficacy of a commonly used progestogen, m edroxyprogesterone acetate (MPA), in the prevention of postoperative a dhesion formation. Design: A double-blind, controlled study evaluated the efficacy of MPA to reduce postoperative adhesion formation and com pared it with other adjuvants and controls in a rat model. Setting: An imal Care Facility of an academic research setting. Subjects: Seventy- five Sprague-Dawley female rats randomly divided into five groups. Int erventions: Three weeks before surgery, the animals from each group we re administered an IM injection of one of the following regimens: [1] 15 mg MPA; [2] both 15 mg MPA and 0.75 mg leuprolide acetate (LA); [3] 0.75 LA; or [4] and [5] comparable volumes of sterile saline. A stand ardized surgical trauma was inflicted in all animals. Before abdominal closure, 2 mt of Ringer's Lactate was instilled in the abdominal cavi ty of all groups except group 5 (controls). Three weeks after surgery, the rats were killed and the adhesions were scored on a scale of 0 to 3 according to their size, thickness, and vascularity. Main Outcome M easure: Postoperative adhesions. Results: The preoperative administrat ion of MPA resulted in the least number and the least severe adhesions . The combination of LA and MPA did not reduce postoperative adhesion formation. Both Ringer's Lactate and LA reduced postoperative adhesion s but not to the same extent as MPA. Conclusion: The preoperative admi nistration of MPA in our laboratory animal model results in the most s ignificant reduction of postoperative adhesion formation. This action of MPA may be mediated by the induction of both a progestational and a hypoestrogenemic milieu. However, the ultimate role of MPA in a clini cal situation requires further investigation.