Spinal cord stimulation for chronic intractable trunk or limb pain: study protocol for a Chinese multicenter randomized withdrawal trial (CITRIP study)

BACKGROUND: Although effective results of many studies support the use of spinal cord stimulation in chronic pain patients, no randomized controlled trial has been undertaken in China to date. CITRIP is a multicenter, prospective, randomized, withdrawal study designed to evaluate the clinical effectiveness and safety of spinal cord stimulation plus remote programming management in patients with intractable trunk or limb pain. METHOD: Participants will be recruited in approximately 10 centers across China. Eligible participants with intractable trunk or limb and an average visual analog scale (VAS) score ≥ 5 will undergo a spinal cord stimulation test. Participants with VAS score reduction ≥ 50% could move forward to receive implantation of an implanted pulse generator. In the withdrawal period at 3-month follow-up visit, participants randomized to the experimental group (EG) will undergo continuous stimulation while ceasing the stimulation in the control group (CG). The outcome assessment will occur at baseline and at 1, 3 (pre- and post-randomization), and 6 months. The primary outcome is the difference of maximal VAS score between EG and CG in the withdrawal period compared with baseline before the withdrawal period. Additional outcomes include VAS score change at 1-, 3-, and 6-month follow-ups; responder rate (VAS score improving by 50%); achievement rate of a desirable pain state (VAS score ≤ 4); awake times during sleep; Beck Depression Inventory for depression evaluation; short-form 36 for quality of life evaluation; drug usage; and satisfaction rating of the device. Adverse events will be collected. The primary analysis will follow the intention-to-treat principle. DISCUSSION: The CITRIP study seeks to evaluate the effectiveness and safety of a randomized withdrawal trial of spinal cord stimulation for patients with intractable trunk or limb pain. TRIAL REGISTRATION: ClinicalTrials.gov NCT03858790. Registered on March 1, 2019, retrospectively registered