P-312 The effectiveness of laparoscopic aspiration and ethanol sclerotherapy (EST) for ovarian endometriomas

Abstract Study question Is EST for endometriomas effective and safe for infertility patients? Summary answer EST is an effective therapy for endometriomas. However, to avoid side effects and achieve efficient results, EST should be performed under laparoscopy. What is known already Although endometriosis is one of the most common diseases in the field of infertility, the relationship between infertility and endometriosis, including abnormal folliculogenesis, elevated oxidative stress, altered immune function, and hormonal milieu, remains controversial. Endometriomas are associated with infections and/or rupture, which can induce serious acute abdomen and may require emergency operation. Compared with laparoscopic cystectomy and/or laser vaporization, there is little evidence available regarding ethanol sclerotherapy for endometriomas. Study design, size, duration A retrospective evaluation of the efficacy of EST was conducted on 308 endometriomas in 260 patients from 1992 to 2023. The endometriomas were divided into 3 groups based on the ethanol instillation time. The instillation time was 4 minutes or less for group 1 (132 endometriomas), 5 to 7 minutes for group 2 (113 endometriomas), and 8 to 10 minutes for group 3 (63 endometriomas). The recurrence rates were evaluated using the Kaplan-Meier curve. Participants/materials, setting, methods The EST procedures were performed under laparoscopy in all patients. The endometriomas were punctured using a 16G needle for smaller cysts and/or a balloon catheter for larger cysts to aspirate the cyst fluid. The inside of cysts was flushed with ethanol three or more times, followed by ethanol instillation. Patients were monitored using transvaginal ultrasound tomography (UST), magnetic resonance imaging (MRI), and Anti-Müllerian hormone (AMH) levels. Main results and the role of chance The mean age of patients was 32.0±4.1 years old. The mean r-AFS score was 53.4±34.2. The mean duration of the follow-up period was 38.0±35.6 months. The mean duration of infertility was 35.3±27.8 months at the time of the operation. The recurrence rate was 18.1% per patient and 16.9% per endometrioma. The highest recurrence rate was observed in group 1 (23.5%), while the lowest was in group 3 (3.2%). Comparison between the recurrence group and non-recurrence group showed no statistically significant differences in age, duration of infertility, or follow-up period. Although not statistically significant, the pregnancy rate in the non-recurrence group (70.0%: 149/213) tended to be higher than that in the recurrence group (55.3%: 26/47). Recurrence rates among the three groups were compared using the Kaplan-Meier curve. The recurrence rate after EST was 17.4% at 10 months and 23.5% at 50 months in group 1, 9.0% at 10 months and 16.8% at 50 months in group 2, and 3.0% at 10, 30, and 50 months in group 3. The AMH level decreased in all patients after EST. Although not statistically significant, AMH levels in the no-recurrence group tended to be higher than those in the recurrence group. Limitations, reasons for caution Cases with two or more endometriomas in a unilateral ovary were omitted; therefore, the effectiveness of EST does not apply to all types of endometriomas. The types of additional treatments after EST varied because all patients underwent infertility treatments. Our study was designed as a retrospective study. Wider implications of the findings Ultrasound-guided transvaginal aspiration was described in almost all reports. Several reports described severe and unusual adhesions surrounding the ovaries, which may have been caused by leaked ethanol. Laparoscopic EST may prevent the spillage of malignant cells, as leakage from endometriomas is minimal or nonexistent. Therefore, laparoscopic EST is recommended. Trial registration number No