Life-table analysis of the success of thermal balloon endometrial ablation in the treatment of menorrhagia

OBJECTIVE: To evaluate the change in intrauterine pressure during thermal balloon endometrial ablation and to identify risk factors associated with treatment failure. DESIGN: Prospective observational study. SETTING: University-affiliated teaching hospital. PATIENT(S): Seventy two consecutive patients with idiopathic menorrhagia refractory to medical treatment. INTERVENTION(S): Thermal balloon endometrial ablation under patient-controlled sedation. MAIN OUTCOME MEASURE(S): Change in intrauterine pressure during the treatment cycle and risk factors associated with treatment failure. RESULT(S): A spontaneous decrease in intrauterine pressure occurred in most patients (93%). The mean (+/-SD) decrease was 34.1 +/- 14.9 mm Hg, or 19.5% +/- 9.1%. The treatment failed in 10 patients (13.9%), and the mean end pressure was significantly lower in this group (131.1 +/- 14.1 mm Hg vs. 145.1 +/- 18.0 mm Hg; P=.02). The chance of success of treatment was significantly lower when the end pressure was <140 mm Hg (odds ratio, 0.42 [95% CI, 0.27 to 0.68]; P=.01), the intrauterine volume was >10 mL (odds ratio, 0.43 [95% CI, 0.22 to 0.83]; P=.058) and the uterus was retroverted (odds ratio, 0.36 [95% CI, 0.20 to 0.65]; P=.008). CONCLUSION(S): Maintaining high intrauterine pressure during the treatment cycle and correction of the retroversion may help to improve treatment success in thermal balloon endometrial ablation.