Morphologic Abnormalities Are Poorly Predictive of Visceral Pain in Chronic Pancreatitis

Objectives: Abdominal pain in chronic pancreatitis (CP) may be visceral or nonvisceral in origin. Differential nerve block (DNB) distinguishes visceral from nonvisceral pain. Endoscopic ultrasound and other imaging tests (eg, computed tomography and magnetic resonance cholangiopancreatography) are used to diagnose and stage CP. However, it is not known whether structural changes predict the presence of visceral pain, which may better respond to endoscopic, surgical, or visceral nerve interventions. We investigated the correlation of pancreatic structural abnormalities evident on imaging tests with the presence of visceral pain on DNB. Methods: A retrospective study was performed. Our DNB database was queried for patients who underwent imaging testing for evaluation of upper abdominal pain. The patients were classified into 3 groups based on structural severity: (1) normal pancreatic imaging, (2) mild CP, and (3) severe CP. The rates of visceral pain in the 3 groups were compared using a chi(2) test. Results: Fifty-four patients were included. There was no significant difference in rates of visceral pain based on structural severity: 48% in normal, 60% in mild CP, 67% in severe CP (chi(2), P = 0.484). Conclusions: The severity of structural changes of CP found on imaging tests does not predict the presence of visceral pain.