Hormone-independent ovarian influence on adhesion development

Objective: To determine which ovarian sex steroid(s), when removed from an intact organism, reduce(s) postoperative adhesion development. Design: Randomized, prospective, blinded study. Setting: University vivarium. Patient(s): One hundred twenty sexually mature female Sprague-Dawley rats, 226-250 g. Intervention(s): Day 0, sham ovariectomy or bilateral ovariectomy, accompanied by continuous-release sex steroid replacement of either no steroids (control), 17β-E₂, natural P (P4), or combined E₂/P4. Day 7, standardized cecal abrasion; day 14, necropsy with assessment of adhesion presence or absence. Main Outcome Measure(s): Adhesion formation. Result(s): Three rats died because of anesthesia or surgical complications, and 117 rats reached necropsy. The ovary-intact (sham) rats adhesion incidence was 60.9%; ovariectomized control rats, 20.8%; E₂, 28.6%; P4, 33.3%; and combined E₂/P4, 24.0%. Despite differing sex steroid replacement, two-tailed χ² testing with correction for multiple comparisons showed no statistical difference in adhesion incidence among the four ovariectomy groups. A statistically significant lower adhesion incidence was noted between the ovary-intact sham cohort and the collective ovariectomy groups and between the sham and ovariectomized control cohorts. Conclusion(s): Ovarian presence or absence at the time of surgical wounding, and not the 17β-E₂ or P milieu, modulates adhesion development. This implicates other ovarian factor(s) in postoperative adhesion development.