Inflammation of the pancreatic gland [pancreatitis] can be acute or chronic. The inciting factor causes the release of autodestructive pancreatic enzymes, resulting in tissue necrosis. Chronic pancreatitis is defined as a progressive and persistent destruction of the parenchyma with ensuing fibrosis and is usually a progressive process.
Etiology
Chronic pancreatitis can be:
- Obstructive type [occurring secondary to tumors/scarring]
- Calcifying type [as is seen in alcohol induced pancreatitis]
- Hereditary
- Other causes such as biliary stones, drugs, autoimmune diseases, certain congenital conditions [pancreatic divisum, cystic fibrosis]
- Idiopathic
The common complications of chronic pancreatitis are diabetes, steatorrhoea and malabsorption. Patients commonly present with symptoms related to the complications and also often complain of chronic back pain. Once diabetes sets in, the abdominal pain often disappears.
Alcoholic pancreatitis:
Alcohol abuse is the most common cause of chronic calcifying pancreatitis and its associated complications [as is seen in this case]. Alcohol abuse causes a disturbance in the cholinergic regulation of pancreatic secretion resulting in decreased citrate levels [citrate chelates calcium] and hence subsequent high levels of calcium occur which precipitate as stones.
Pathogenesis :
New evidence in the literature now supports the hypothesis that alcoholic pancreatitis begins as an acute process and repeated acute episodes lead to the exocrine and endocrine dysfunction of the pancreas. However not all chronic alcoholics develop this dysfunction and other associated factors such as genetics related to ethanol metabolism, viral infection and tobacco consumption [the latter also an independent risk factor] have been implicated.
Since these patients present with recurrent abdominal pain, ultrasound is often the initial test performed.
Ultrasound features of the alcohol damaged pancreas :
- A normal or below normal size of the pancreas
- A heterogeneous echotexture
- Tiny bright reflectors or speckles with irregular margins within the organ, suggestive of calcifications. Discrete, chunky calcifications are seen in tropical pancreatitis. Pancreatic ductal calculi may also be seen.
- Pancreatic ductal dilatation [>3 mm]. The dilatation is beaded and irregular, versus regular dilatation seen in malignancy.
If associated complications develop, ultrasound demonstrates:
- Pseudocysts - seen as cystic masses in the peri and intrapancreatic regions.
- Vascular abnormalities such as pseudoaneurysms.
Endoscopic ultrasound [EUS] is more sensitive in detecting the early changes of chronic alcoholic pancreatitis. A study by Kahl, et al reported 100% sensitivity in detecting the changes associated with early chronic pancreatitis by EUS even when endoscopic retrograde cholangio-pancreatography [ERCP] was normal. The other modalities that could be used to image this condition include helical CT with CT cholangiography, MR with MR cholangio-pancreatography [MRCP] and ERCP.