Ultrasound-guided aspiration and ethanol sclerotherapy (EST) for treatment of cyst recurrence in patients after previous endometriosis surgery: analysis of influencing factors using a decision tree.

STUDY OBJECTIVE: To evaluate the efficiency of transvaginal aspiration accompanied by ethanol sclerotherapy for treating cyst recurrence in patients who have previously undergone surgery to treat endometriosis and to analyze various factors that influence success rates using a data mining system.

DESIGN: Retrospective cohort study (Canadian Task Force classification II-3).

SETTING: Teaching hospital affiliated with Chang Gung University, Taoyuan, Taiwan.

PATIENTS: One hundred ninety-six patients with endometrioma recurrence.

INTERVENTION: A total of 274 transvaginal aspirations followed by sclerotherapy with 95% ethanol. Treatment times varied from immediate removal (0-10 minutes) to in situ retention. Patients were followed up at 3, 6, and 12 months to detect complications, determine the size and persistence of cysts, obtain the pelvic pain score, and assess for pregnancy or the need for repeat surgical intervention. A decision tree was used to determine factors from the collected data that most influenced the success of treatment.

MEASUREMENTS AND MAIN RESULTS: Cyst size was consistently reduced until 6 months after ethanol sclerotherapy. The mean (SD) cyst reduction rate was 37.2% (42.2%), and the pain score reduction rate was 20.5% (71.5%). The antral follicle count was simultaneously increased by 36.4%. Sixty-three patients (23%) required repeated surgery during the observation period and were treated with either repeat aspiration (13.5%) or major laparoscopic or open laparotomic interventions (8.4%). Eighteen of 101 infertile patients (17.8%) achieved pregnancy. The total recovery rate (pregnancy or no persistence of symptoms or cyst) was significantly higher in patients in the groups that received longer treatment (7-10 minutes and retention) than in the groups with shorter treatment (0-6 minute) (47.0% vs 28.7%; p < .005). The highest recovery rate was observed in patients with longer treatment time, smaller cysts (≤5.05 cm), lower CA 125 level (≤62.03 IU/mL), and fewer cysts (≤3 cm) (35 of 49 [71.4%]). In patients with larger cysts and cysts with clear contents, better success can be achieved with longer treatment. The use of postoperative ovarian suppression, traditional Chinese medicine, or no therapy for 6 months before the study was not significant among groups.

CONCLUSION: Ultrasound-guided sclerotherapy with 95% ethanol retention is an effective alternative therapy for recurrent ovarian endometrioma, in particular in selected patient groups.