Interventional Pain Management Approaches for Control of Chronic Pancreatic Pain

16. Pain in chronic pancreatitis

INTRODUCTION

Chronic pancreatitis is defined as a disease of the pancreas in which recurrent inflammatory episodes result in replacement of the pancreatic parenchyma by fibrous connective tissue in individuals with genetic, environmental, and other risk factors. Pain is one of the most important symptoms of chronic pancreatitis and, in many cases, has chronic visceral nociceptive, nociplastic, and even neuropathic components, with evidence of both central and peripheral sensitization, neuroplasticity, and neurogenic inflammation.

METHODS

The literature on the diagnosis and treatment of pain in chronic pancreatitis was reviewed and summarized.

RESULTS

Treatment of abdominal pain in chronic pancreatitis is guided by pancreatic morphology on imaging, although the correlation between pain symptoms and pathoanatomical changes is not always straightforward. Patients with pancreatic duct obstruction are initially offered endoscopic or surgical therapies, while non-obstructive disease is mostly managed medically. Lifestyle changes and psychological support are of particular importance for all chronic pancreatitis patients. Analgesic options range from non-opioid medications to opioids and adjuvant agents. Interventional pain management may consist of radiofrequency treatment of the splanchnic nerves and spinal cord stimulation. To date, there are no randomized trials supporting their efficacy in the treatment of chronic pancreatitis pain, and the recommendation to consider these treatment options is justified by evidence from observational studies. Possible opioid-sparing effects of interventional pain treatments are important to consider because opioid use and dependency are common in chronic pancreatitis patients and associated with worse outcomes. Celiac plexus block is not generally recommended for chronic pancreatitis due to the limited quality of evidence, overall short duration of effect, and invasiveness of the procedure. Central sensitization can impact the effectiveness of invasive treatments.

CONCLUSIONS

Managing pain in chronic pancreatitis is a complex task that requires a multidimensional and individualized approach. Due to the lack of randomized trials, treatment decisions are often guided by expert opinion. Integrating pharmacological and non-pharmacological interventions and collaborating with a multidisciplinary team are key components of effective chronic pancreatitis pain management.

Spinal Cord Stimulation for Visceral Pain: Present Approaches and Future Strategies

INTRODUCTION

The introduction of successful neuromodulation strategies for managing chronic visceral pain lag behind what is now treatment of choice in refractory chronic back and extremity pain for many providers in the United States and Europe. Changes in public policy and monetary support to identify nonopioid treatments for chronic pain have sparked interest in alternative options. In this review, we discuss the scope of spinal cord stimulation (SCS) for visceral pain, its limitations, and the potential role for new intradural devices of the type that we are developing in our laboratories, which may be able to overcome existing challenges.

METHODS

A review of the available literature relevant to this topic was performed, with particular focus on the pertinent neuroanatomy and uses of spinal cord stimulation systems in the treatment of malignant and nonmalignant gastrointestinal, genitourinary, and chronic pelvic pain.

RESULTS

To date, there have been multiple off-label reports testing SCS for refractory gastrointestinal and genitourinary conditions. Though some findings have been favorable for these organs and systems, there is insufficient evidence to make this practice routine. The unique configuration and layout of the pelvic pain pathways may not be ideally treated using traditional SCS implantation techniques, and intradural stimulation may be a viable alternative.

CONCLUSIONS

Despite the prevalence of visceral pain, the application of neuromodulation therapies, a standard approach for other painful conditions, has received far too little attention, despite promising outcomes from uncontrolled trials. Detailed descriptions of visceral pain pathways may offer several clues that could be used to implement devices tailored to this unique anatomy.

An 18-Year-Old With Acute-on-Chronic Abdominal Pain

An 18-year-old woman with a complex past medical history presented with 2 days of vomiting and lower abdominal pain. She had been admitted for the majority of the previous 5 months for recurrent pancreatitis and had undergone a cholecystectomy. Additional symptoms included nausea, anorexia, constipation, and a 40-lb weight loss over 4 months. She appeared uncomfortable, and an examination was remarkable for tachycardia, hypertension, and diffuse abdominal tenderness to light palpation. Her initial laboratory test results revealed mildly elevated liver enzymes (aspartate aminotransferase 68 U/L, alanine aminotransferase 80 U/L) and a normal lipase. She was admitted for pain control and nutritional support. Over the next few days, the lipase increased to 1707 U/L. Despite optimizing her management for acute pancreatitis, the patient's symptoms persisted. Further history gathering and laboratory testing ultimately revealed her diagnosis. Our expert panel reviews her hospital course and elucidates the management of our eventual diagnosis.

Opioid misuse in gastroenterology and non-opioid management of abdominal pain

Opioids were one of the earliest classes of medications used for pain across a variety of conditions, but morbidity and mortality have been increasingly associated with their chronic use. Despite these negative consequences, chronic opioid use is increasing worldwide, with the USA and Canada having the highest rates. Chronic opioid use for noncancer pain can have particularly negative effects in the gastrointestinal and central nervous systems, including opioid-induced constipation, narcotic bowel syndrome, worsening psychopathology and addiction. This Review summarizes the evidence of opioid misuse in gastroenterology, including the lack of evidence of a benefit from these drugs, as well as the risk of harm and negative consequences of opioid use relative to the brain-gut axis. Guidelines for opioid management and alternative pharmacological and nonpharmacological strategies for pain management in patients with gastrointestinal disorders are also discussed. As chronic pain is complex and involves emotional and social factors, a multimodal approach targeting both pain intensity and quality of life is best.