Letter to the Editor: “Ultrasound-guided sclerotherapy for the treatment of ovarian endometrioma: an updated systematic review and meta-analysis”

by Saveria Cremona (s.cremona@smd20.qmul.ac.uk>)

Ultrasound-guided sclerotherapy for the treatment of ovarian endometrioma: an updated systematic review and meta-analysis

Dear Editor-in-Chief,

I have read the systematic review by Kim et al [1]. I commend the authors for successfully concluding that laparoscopic sclerotherapy is a safe and effective treatment for ovarian endometriomas and highlighting the need for larger scale randomised controlled trials (RCTs) to support their findings.

Recent literature on Ultrasound Guided sclerotherapy has used ethanol as an instillation agent, as studies have shown its superiority over methotrexate or tetracycline [2]. In fact, papers included in this metanalysis with the latter two agents date from 1997 to 2011, whilst ethanol as a sclerosant is being looked at currently in RCTs [3]. Had the authors chosen to look solely at ethanol, they might have had more significant results, and less heterogeneity. No attempt was made to perform a meta-analysis between the different sclerosants in this review.

Eighteen out of 28 studies had population sizes < 50, and no analysis was performed to determine if the procedure had different efficacy profiles for recurrent vs primary endometriomas, the concentration or volume of sclerosant used, which varied significantly across studies. I acknowledge that significant heterogeneity was difficult to avoid with such small study populations in observational studies, and although the authors did include an RCT as part of their meta-analysis, it was performed in 2011 and used methotrexate as a sclerosing agent [4].