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E Guidelines A-Z Index A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Entitlement Eligibility GuidelinesChronic Pancreatitis
DefinitionChronic Pancreatitis is a chronic inflammatory disease of the pancreas characterized by progressive fibrosis, and destruction of exocrine tissue and endocrine tissue. Please note: Entitlement should be granted for a chronic condition only. For VAC purposes, "chronic" means that the condition has existed for at least 6 months. Signs and symptoms are generally expected to persist despite medical attention, although they may wax and wane over the 6 month period and thereafter. Back to TopDiagnostic StandardA diagnosis from a qualified medical practitioner is required, supported by test results of serum amylase. The following investigations are normally conducted but are not mandatory:
Endoscopic retrograde cholangio-pancreatography (ERCP) is conducted on occasion. Evidence of duration of a disability for at least 6 months should be provided. Back to TopAnatomy and PhysiologyThe pancreas is an elongated organ located in the retroperitoneal space with its head within the curve of the duodenum and its tail extending towards the spleen. The retroperitoneal location and the absence of a capsule surrounding the pancreas are important factors in understanding how pancreatitis evolves. Pancreatic inflammation and fibrosis may spread unimpeded by anatomic barriers to involve the spleen, the splenic artery and vein, the duodenum and distal common bile duct, the mesocolon, the diaphragm and pararenal spaces, the lesser omental sac, and the celiac and superior mesenteric ganglia. The acinar cells of the exocrine pancreas synthesize approximately 20 digestive enzymes including colipase, a secretory trypsin inhibitor, and lithostathine S 2-5, a protein that inhibits the precipitation of calcium carbonate from pancreatic juice. These secretory proteins are sorted into condensing vacuoles, which then become zymogen granules. Premature activation of zymogens within the pancreas is the key event in the pathogenesis of acute pancreatitis. Protein and calcium carbonate precipitate within the pancreatic duct system play a major role in the development of chronic pancreatitis. Acute pancreatitis is an acute inflammatory condition due to auto-digestion of pancreatic tissue by its own enzymes, typically presenting with abdominal pain. It is usually associated with raised pancreatic enzymes in blood or urine. Only rarely does acute pancreatitis lead to chronic pancreatitis. Chronic pancreatitis may follow acute pancreatitis when there have been disturbances of the duct system, most frequently produced when trauma is the inciting cause. Degrees of severity vary, with severe representing multisystem failure and/or development of a complication. There are many accepted causes of acute pancreatitis. There must be many patho-physiological mechanisms involved but the basic abnormality appears to be release from the pancreatic acinar cells of activated enzymes into the pancreatic and surrounding tissue due to disturbances in the plasma membranes of the pancreatic acinar cells. Chronic pancreatitis is a chronic inflammatory condition typically presenting with chronic abdominal pain and a progressive fibrosis of the pancreas with loss of exocrine (steatorrheoa) and endocrine (diabetes mellitus) function. Acute relapsing pancreatitis (recurrent attacks of acute pancreatitis) are often superimposed. The disease may be focal, segmental or diffuse. Clinically and pathologically there may be episodes of acute pancreatic inflammation during the course of the disease, leading to nearly all the possible complications of acute pancreatitis. Chronic pancreatitis may be caused by pancreatic duct obstruction. Relief of the obstruction cannot only arrest the progress of the disease but can lead to some restitution of morphology and function. It may be at a stage in which fibrosis, the end result of chronic inflammation, may replace the gland completely without any evidence of active inflammation or pancreatic acinar tissue when examined. Specific diseases involving fibrosis and acinar atrophy in the pancreas, e.g. cystic fibrosis of the pancreas and hemochromatosis, are not considered under the name of chronic pancreatitis. Chronic pancreatitis can occur, but not necessarily with the same clinical course as in alcoholic or idiopathic chronic pancreatitis, in the following conditions:
Pancreatic pseudocysts are a circumscribed local accumulation of leaking pancreatic secretions that occur as the result of pancreatic inflammation. Pseudocysts can develop a fibrous pseudo capsule and may contain bacteria and inflammatory cells but no liquefaction necrosis of the pancreas. They do not have an epithelial lining. Acute and chronic pseudocysts occur and a significant number of acute pseudocysts resolve slowly spontaneously over weeks. Unresolved pseudocysts can lead to complications which can be fatal. Back to TopClinical FeaturesChronic inflammatory disease of the pancreas may present as episodes of acute inflammation in a previously injured pancreas or as chronic damage with persistent pain and malabsorption. The classic presentation of acute pancreatitis is development of steady, dull or boring pain in the mid-epigastric area. It is often associated with nausea and vomiting. Pain may radiate to the back or chest. Persons may go on to develop low grade fever, hypotension and tachycardia. One to two weeks later ecchymoses may appear in the flanks (Grey Turner's sign) or umbilicus (Cullen's sign). The clinical manifestations of chronic pancreatitis comprise abdominal pain, followed by the results of progressive loss of exocrine and endocrine function (leading to maldigestion and malabsorption of nutrients and glucose intolerance). A proportion of cases of chronic pancreatitis are pain-free. Loss of 80% of exocrine function can occur without demonstrable abnormality in digestion or absorption. Diabetes mellitus is not likely to occur unless more than 80% of the gland has been destroyed. Because of coexisting loss of glucagon from islet cells, the diabetic status in chronic pancreatitis is frequently brittle. Steatorrhea does not occur unless the secretion of pancreatic lipase is reduced to less than 10% of normal. Thus, steatorrhea is not common in chronic pancreatitis unless there is substantial damage to the pancreas or complete blockage of the pancreatic duct in the head of the gland. It is not possible to say when or how chronic pancreatitis (of any cause) begins. There is no pancreatic function test that has been shown to be sensitive in recognizing early chronic pancreatitis. This often results in a delay in establishing a diagnosis of chronic pancreatitis. ERCP and computerized scanning may show apparent minor abnormalities, but as yet there has been incomplete correlation with morbid anatomy. Only major changes from normal can be interpreted with confidence in well-advanced disease. Back to TopPension Considerations
References for Chronic Pancreatitis
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