Chronic pancreatitis: controversies in etiology, diagnosis and treatment.

The pathogenesis of idiopathic chronic pancreatitis remains poorly understood despite the high expectations for ascribing the pancreatic damage in affected patients to genetic defects. Mutations in the cationic trypsinogen gene, pancreatic secretory trypsin inhibitor, and the cystic fibrosis conductance regulator gene do not account for the chronic pancreatitis noted in most patients with idiopathic chronic pancreatitis. Small duct chronic pancreatitis can be best diagnosed with a hormone stimulation test. Endoscopic ultrasonography can detect abnormalities in both the parenchyma and ducts of the pancreas. The true value of endoscopic ultrasonography in diagnosing small duct chronic pancreatitis remains to be fully defined and is under active investigation. It is not clear whether endoscopic ultrasonography is more sensitive for early structural changes in patients with small duct disease or is over diagnosing chronic pancreatitis. Pancreatic enzyme supplementation with non-enteric formulation along with acid suppression (H2 blockers or proton pump inhibitors) is an effective therapy for pain in patients with small duct chronic pancreatitis. The role of endoscopic ultrasonography-guided celiac plexus block should be limited to treating those patients with chronic pancreatitis whose pain has not responded to other modalities. Total pancreatectomy followed by autologous islet cell autotransplantation appears to be potential therapeutic approach but for now should be considered experimental.