Chronic pancreatitis is an inflammatory and fibrosing disease of the exocrine pancreas characterized by irreversible morphological changes and permanent loss of function. The apparent incidence of chronic pancreatitis has increased approximately fourfold over the past several decades, likely due a broadening of its definition and the inclusion of patients with earlier-stage disease. The natural history of chronic pancreatitis is unpredictable. Affected individuals typically suffer a pattern of persistent or recurrent attacks of pain along with progressive pancreatic exocrine insufficiency. Symptoms may also result from extension of the disease process to adjacent organs and vascular structures. In later stages, pancreatic endocrine insufficiency may develop. Decision making in the management of chronic pancreatitis must be individualized to the specific anatomic and pathological circumstances, taking into account the extent of local expertise in various diagnostic and therapeutic modalities as well as the fact that there is a relative paucity of high-quality data on the clinical effectiveness of surgical and medical interventions. Optimal management is facilitated by a multidisciplinary approach that includes surgical, endoscopic, and radiological expertise in addition to nutrition, endocrinology, pain management, and psychosocial support.
Pancreatitis is thought to have its origin as an autodigestive disease initiated by inappropriate activation of pancreatic zymogens. The terms acute pancreatitis and chronic pancreatitis are often used to draw the temporal distinction between an isolated episode and a more persistent illness associated with progressive loss of pancreatic function. In fact, pancreatitis represents a far more heterogeneous clinical entity than can be captured by these two simple descriptors. A number of international conferences have been held in order to develop uniform terminology to characterize the spectrum of morphology seen in acute and chronic pancreatitis.
According to the Marseille-Rome classification of 1988, the term acute pancreatitis is used to refer to single or repeated episodes of abdominal pain associated with a range of potentially reversible pancreatic lesions including pancreatic edema, necrosis, and hemorrhage, as well as peripancreatic fluid collections, necrosis, and pseudocysts. Chronic pancreatitis is used to refer to recurrent or persistent abdominal pain that is associated with irreversible and ongoing inflammatory destruction of exocrine parenchyma and, eventually, islets. In practice, however, the distinction between acute and chronic pancreatitis is rarely made based on tissue sampling, and there is no consensus on the definition of irreversible morphological change.1 It is also acknowledged that certain forms of chronic pancreatitis can occur in the absence of pain.
The Marseille-Rome classification further divides chronic pancreatitis into several morphological subtypes that may coexist in the same patient. Chronic obstructive pancreatitis is characterized by exocrine atrophy and is associated with duct stenosis caused by tumors, pseudocyst, or scarring from prior acute pancreatitis. Chronic calcifying pancreatitis is characterized by intraductal calcifications and protein plugs, and is often associated with atrophy, stenotic ducts, and areas of acute inflammation or pseudocyst. Chronic inflammatory pancreatitis consists of dense infiltration of mononuclear inflammatory cells. Retention cysts and pseudocysts, seen in both calcifying and obstructive forms, ...