Role of differential neuroaxial blockade in the evaluation and management of pain in chronic pancreatitis

OBJECTIVES: Chronic pancreatic pain is difficult to treat. Surgical and medical therapies directed at reducing pain have met with little long-term success. In addition, there are no reliable predictors of response including pancreatic duct diameter. A differential neuroaxial blockade allows characterization of chronic abdominal pain into visceral and nonvisceral pain origins and may be useful as a guide to the treatment. Pain from an inflamed, and scarred pancreas should be visceral in origin. The purpose of our study was to determine the frequency with which patients with chronic pancreatitis have visceral pain and whether our modified differential neuroaxial blockade technique using thoracic epidural analgesia can accurately predict which patients will respond to medical or surgical therapy. METHODS: We retrospectively reviewed the medical records of patients with a firmly established diagnosis of chronic pancreatitis (Cambridge classification, calcifications) who had undergone a differential neuroaxial block for their chronic abdominal pain evaluation. Patient demographics and medical or surgical treatment for pancreatic pain was recorded. Response to therapy was defined by a 50% reduction in pain by verbal response score. RESULTS: A total of 23 patients were identified. Alcohol was the most common etiology for chronic pancreatitis (15 of 23, 55%). Surprisingly, the majority of chronic pancreatitis patients had nonvisceral pain (18 of 23, 78%) and only 22% (5 of 23) had visceral pain by differential neuroaxial block. Four of five patients (80%) with visceral pain responded to therapy, whereas only 5 of 17 (29%) of patients with nonvisceral pain responded. CONCLUSIONS: Surprisingly, patients with chronic pancreatitis commonly have nonvisceral pain. Differential neuro-axial blockade can predict which patients will respond to therapy.