The Efficacy of Gnrh-A Followed by Sanjiezhentong Capsules in Long-Term Management of Endometriosis: Study Protocol for a Prospective, Randomized, Multicenter, Double-Blinded, Double-Dummy Parallel-Group Clinical Trial

Background: Endometriosis is a common benign gynecological disorder with high risk of recurrence and adverse impact on fertility-sparing. This study aims to evaluate the effectiveness and safety of SanJieZhenTong Capsules, a traditional Chinese medicine, in the long-term management of endometriosis postoperatively. Methods and analysis: A prospective, double-blinded, double-dummy parallel-group randomized controlled trial will be conducted at three university-based medical centers in China. A total of 600 patients with rAFS III-IV endometriosis diagnosed by laparoscopy will be enrolled. After fundamental treatment (gonadotropin-releasing hormone agonists injection starts on the first day of menstruation postoperatively, and repeats 3 times every 28 days), participants will be randomly allocated to the oral contraceptive group (oral contraceptive + dummy A) or SanJieZhenTong Capsules group (SanJieZhenTong Capsules + dummy B) in a 1:1 ratio. All participants will be treated and followed up for 52 weeks. The primary outcome is a recurrence rate based on endometriosis-related symptoms, physical examination, and/or ultrasound/MRI findings. The secondary outcome includes changes in quality of life and organic function outcome via the 36-item Short-Form scores and gastrointestinal function score. Conclusion: The current trial could provide rigorous evidence on SanJieZhenTong Capsules application in the long-term management of advanced-stage endometriosis.