Manual acupuncture plus usual care versus usual care alone in the treatment of endometriosis-related chronic pelvic pain : study protocol for a randomised controlled feasibility study

Background: Endometriosis is the most common cause of chronic pelvic pain worldwide. Non-surgical treatments are effective for only 30–50% of women and have a significant side effect burden that leads to high discontinuation rates. Surgery can be effective but is expensive and invasive, and symptoms tend to recur within 5 years. There is early evidence that acupuncture may be effective in treating endometriosis-related chronic pelvic pain, showing clinically significant analgesia. Both levels of inflammation and pain processing have been shown to be altered in women with chronic pelvic pain. Acupuncture has been shown to reduce inflammation and change central pain processing in other conditions, but research on women with endometriosis is currently lacking. The aim of this feasibility study is to provide data on recruitment rates, retention, appropriateness of outcome measures, minimal clinically important difference in numeric rated scales for pain and the potential effect of acupuncture on pain processing and markers of inflammation in endometriosis-related CPP. Methods: We will include women aged 18–45 years with a diagnosis of endometriosis via laparoscopy in the past 5 years. A total of 30 participants will be recruited and randomly allocated in a 1:1 ratio to receive acupuncture or usual care. Women in the acupuncture group will receive two 45-min treatment sessions per week for 8 weeks (total of 16 sessions). Women in the usual care group will continue with their current treatment regimen. The primary feasibility outcomes are recruitment rates, retention rates and the safety and acceptability of the intervention; secondary patient-centred outcomes include a change in 0–10 daily pelvic pain ratings, the Endometriosis Health Profile 30 (EHP-30) and changes in conditioned pain modulation, resting and task-related EEG activity and inflammatory markers. Analyses will be performed blind to group allocation. Discussion: This is a two-armed, assessor blind, randomised controlled feasibility trial. Data will be compared at baseline and trial completion 8 weeks later. Outcomes from this feasibility study will inform a larger, fully powered clinical trial should the treatment show trends for potential effectiveness.