Intrathecal drug delivery for chronic abdominal pain: A case series.

INTRODUCTION

Chronic Abdominal Pain (CAP) is a pervasive and challenging global health issue. In a 2023 United States National Health Interview Survey, CAP was present in almost 3 % of all respondents. Various interventional procedures, such as sympathetic nerve blocks (SNBs), thoracolumbar sympathetic ablations, and spinal cord stimulation (SCS), have shown mixed efficacy in managing CAP. This case series describes refractory CAP that is effectively managed with IDD after a treatment algorithm to first distinguish nociceptive pain from a centrally mediated process, but only when the AGA ROME IV criteria for CAP is met.

METHODS

Four patients were identified in clinical practice as suitable candidates for an IDD for refractory, non-centrally mediated CAP. Two of the patients had constant CAP meeting the ROME IV AGA diagnostic criteria for CAP and therefore underwent a DDE-ultimately with findings suggestive of visceral or somatic pain given a >70 % reduction in pain after administration of the local anesthetic and confirmation of a sensory level change, but not after the administration of normal saline prior. (Tabe 1). All patients underwent a continuous intrathecal catheter trial, except for one patient with cystic fibrosis and unpredictable pancreatitis pain episodes, who had failed a spinal cord stimulator implant and proceeded straight to an IDDS implant.

RESULTS

IDD effectively managed refractory CAP across these four cases, with implantation durations ranging from 1.5 to 10 years. All patients remained off systemic opioids and maintained complete functional independence-specifically their Activities of Daily Living (ADLs) as well as Instrumental ADLs.

DISCUSSION: Effective management of CAP begins with a precise diagnosis that distinguishes between nociceptive and centrally mediated pain. Once centrally mediated pain is excluded, and provided patients did not experience sufficient analgesia with other less invasive interventions, targeted treatment for visceral/nociceptive pain with intrathecal drug delivery can be attempted. This case series highlights IDD as a promising alternative to other interventional therapies for refractory CAP, offering durable pain relief with potentially fewer complications.