Impact of Female Reproductive Hormones on Surgically Induced Hemorrhage: A Translational Animal Model

Objectives: To establish an animal model for investigating the impact of female reproductive hormones on perioperative blood loss during cranio-maxillofacial surgery. Methods: Forty female Sprague-Dawley rats were sequentially allocated into five groups (n = 8 each): one sham-operated group (SHAM) receiving vehicle and four ovariectomized groups (OVX) receiving either the vehicle, 17β-estradiol, progesterone, or follicle-stimulating hormone-β. Successful ovariectomy was verified by monitoring body mass and measuring terminal serum hormone concentrations. Following a 13-day hormonal regimen, all subjects underwent a standardized surgical procedure to induce mandibular hemorrhage. Perioperative blood loss was quantified gravimetrically until complete hemostasis. Results: In the primary analysis, total blood loss differed among the four OVX groups (p = 0.038), with lower blood loss observed in the 17β-estradiol-treated OVX rats (OVX+E) compared to the vehicle-treated OVX controls (p = 0.0495), though sensitivity analyses indicated that this finding should be interpreted with caution. Conclusions: Within the limitations of this study, 17β-estradiol treatment was associated with lower perioperative blood loss in ovariectomized female rats following surgically induced mandibular hemorrhage. This finding suggests that estradiol exposure may influence perioperative bleeding and highlights the need for confirmation in larger, adequately powered studies to further investigate the potential role of estradiol in the preoperative risk assessment of female patients undergoing cranio-maxillofacial procedures.