The effect of aqueous progesterone on operative adhesion formation.

Progesterone (P) has been shown to have antiinflammatory and immunosuppressive properties. This study was designed to evaluate these effects on operative adhesion formation. Forty guinea pigs received standardized injuries to their uterine horns. Four groups were examined. Normal saline was used as an irrigant in the first, or control, group. Aqueous P (50 mg or 1 ml) was dripped over the injured site and instilled intraperitoneally in the second group. The third group received intramuscular aqueous P (3.3 mg/kg body weight) 1 day postoperatively, the day of surgery, and either 6 or 13 days postoperatively until reexploration. In the fourth group 1 ml of 32% dextran 70 (Hyskon) was administered in the same manner as aqueous P in the second group. The animals in all groups were reexplored 1 or 2 weeks after the initial surgical procedure, and the adhesions were scored. Adhesion formation was significantly reduced (P less than 0.001) in all treatment groups when compared with the control group. Aqueous P may have a role in the prevention of adhesion formation associated with pelvic surgery and, in particular, microscopic tubal and ovarian surgery.