Chronic pancreatitis.

The pathogenesis of idiopathic chronic pancreatitis remains poorly understood despite the high expectations for ascribing the pancreatic damage in affected patients to genetic defects. Neither mutations in the cationic trypsinogen gene nor mutations of the cystic fibrosis conductance regulator gene account for the chronic pancreatitis noted in most patients with idiopathic chronic pancreatitis. Attempts to find an autoimmune basis for the pancreatitis in these patients have not been very successful. The diagnosis of small duct idiopathic chronic pancreatitis remains a great source of frustration for clinicians. Such patients with negative results of radiographic studies often cannot be diagnosed unless a hormone stimulation test such as a secretin test is performed. Although the porcine biologic form of secretin, which has been used to diagnose chronic pancreatitis, became unavailable because of widespread use in the treatment of children with autism, a synthetic form of porcine secretin has now been approved by the US Food and Drug Administration and is available. The true value of endoscopic ultrasonography in diagnosing small duct chronic pancreatitis remains to be fully defined. Endoscopic ultrasonography is becoming the test of choice in detecting radiographic abnormalities in both the parenchyma and ducts of the pancreas. Endoscopic ultrasonography-guided celiac plexus block can be performed relatively easily and very safely. It can provide excellent short-term pain relief in some patients, but reliable predictors of which patients will be successful with this therapy are not yet available. Because long-term follow-up data on the use of endoscopic ultrasonography in this respect are not available, and because the pain of chronic pancreatitis is, indeed, chronic, 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.