Investigating the efficacy of electroacupuncture for postoperative ileus in patients with colorectal cancer: study protocol for a multicentre clinical trial with neuroimaging assessment.

introductionPostoperative ileus (POI) is a prevalent complication following abdominal surgeries, significantly compromising patients' quality of life and imposing a socioeconomic burden. Electroacupuncture (EA), a widely used therapeutic approach in China, has shown promise as an effective intervention for POI. However, the neural mechanism underlying its therapeutic effects remains unclear. Thus, this study aims to evaluate the efficacy of EA treatment for POI and investigate its central mechanism by functional MRI (fMRI). METHODS AND ANALYSIS: This randomised controlled clinical trial will be conducted across three hospitals in China. A total of 50 eligible patients with colorectal cancer scheduled for elective laparoscopic surgery will be randomly assigned to either the EA or sham electroacupuncture (SA) group in a 1:1 ratio. All patients will undergo 5 sessions of 30 min EA or SA over 5 consecutive days post-surgery (once daily). Resting-state fMRI (rs-fMRI) scans will be performed at baseline and the end of treatment to examine brain functional changes related to EA treatment. The primary outcome is the time to first defecation. Secondary outcomes include the time to first flatus, ambulation, tolerability of semiliquid and solid food; length of postoperative hospital stay; severity of postoperative pain, abdominal distension and nausea; frequency of postoperative nausea and vomiting episodes; rate of readmission. Postoperative complications will be monitored and documented throughout the trial duration. Credibility and expectancy evaluation, along with blinding assessment, will be conducted after the first treatment session. Pearson/Spearman correlation analysis will be performed to determine the relationship between clinical variables and rs-fMRI metrics. ETHICS AND DISSEMINATION: This protocol has been approved by the ethics committees of Beijing University of Chinese Medicine (number 2024BZYLL0113), Cancer Hospital Chinese Academy of Medical Sciences (number 24/323-4603), Beijing Friendship Hospital Affiliated to Capital Medical University (number 2024-P2-081-01) and Beijing Chaoyang Huanxing Cancer Hospital (number 2024-011-02). Participants will sign the paper-based informed consent form before enrolment. The results will be disseminated through peer-reviewed publications. TRIAL REGISTRATION NUMBER: ITMCTR2024000504.