Spinal Cord Stimulation for Chronic Visceral Abdominal Pain

Background. Spinal cord stimulation (SCS) may reduce pain scores and improve function in patients with chronic visceral abdominal pain. We thus present our large clinical experience in SCS for visceral abdominal pain. Methods. We trialed spinal cord stimulation in 35 patients, each of whom was shown by retrograde differential epidural block to have either visceral pain (n = 32) or mixed visceral and central pain (n = 3). SCS trials lasted 4 to 14 days (median 9 days). SCS lead tips were mostly positioned at T5 (n = 11) or T6 (n = 10). Results. Thirty patients (86%) reported at least 50% pain relief upon completion of the trial. Among these, pretrial visual analog scale (VAS) pain scores averaged 8.2 +/- 1.6 (SD) and opioid use averaged 110 +/- 119 mg morphine sulfate equivalents. During the trial, VAS pain scores decreased to 3.1 +/- 1.6 cm (P < 0.001, Mann-Whitney Rank Sum Test) and opioid use decreased to 70 +/- 68 mg morphine equivalent a day (P = 0.212). Five patients failed the trial, one was lost to follow-up, and 19 were followed for the whole year. Seven patients were either followed for less than a year (n = 3) or the SCS system was removed due to infection or lead migration (n = 4). One patient despite the successful trial felt no improvements at 6 months after the implant and requested an explant of the SCS device. Among the 28 patients who received permanent implant, 19 were followed at least a year. Their VAS pain scores remained low (3.8 +/- 1.9 cm; P < 0.001) at 1 year, as did opioid use (38 +/- 48 mg morphine equivalents; P = 0.089). Conclusions. Spinal cord stimulation may be a useful therapeutic option for patients with severe visceral pain.