Chronic pancreatitis is an irreversible chronic inflammatory condition of the pancreatic parenchyma and ducts caused by various factors. It is characterized by recurrent episodes of upper abdominal pain along with progressive decline or loss of pancreatic exocrine and endocrine functions.
Etiology
Chronic and excessive consumption of alcohol and smoking are the most common risk factors, as ethanol and tobacco exert direct toxic effects on the pancreas. In addition, genetic predisposition, autoimmune conditions, and pancreatic duct obstruction from various causes are also associated with the disease. A small number of cases have an unknown etiology.
Pathology
The hallmark pathological changes include pancreatic gland atrophy and fibrosis, which manifest as irregular, nodular sclerosis. The pancreatic ducts exhibit stenosis with segmental dilation and may contain pancreatic stones or cyst formation. Microscopically, there is marked proliferation of fibrous tissue, loss of acinar cells, cell shrinkage, calcifications, and ductal strictures. Dense collagen deposition and fibroblast proliferation separate pancreatic islet cells. In rare cases, cancer may develop on the foundation of chronic pancreatic inflammation.
Clinical Manifestations
Abdominal pain is the most common symptom. The pain typically occurs in the upper abdomen below the xiphoid process or slightly to the left and often radiates to the lower back in a band-like pattern, with a prolonged duration. Patients may experience appetite loss and weight loss, as well as insulin-dependent diabetes mellitus and steatorrhea. Abdominal pain, weight loss, diabetes mellitus, and steatorrhea are collectively referred to as the tetra-syndrome of chronic pancreatitis. Enlargement of the pancreatic head may compress the common bile duct, resulting in jaundice.
Diagnosis
Diagnosis is suggested by the presence of typical clinical manifestations.
Ultrasound may reveal localized pancreatic nodules, pancreatic duct dilation, cyst formation, pancreatic enlargement, or fibrosis. The presence of pancreatic duct stones is indicated by hyperechoic regions with accompanying acoustic shadows.
Plain X-rays may show pancreatic calcifications or pancreatic duct stones.
CT scans can detect pancreatic duct stones, changes in pancreatic parenchymal density with scattered calcifications, and pancreatic duct dilation. CT may also reveal complications of chronic pancreatitis, such as malignant transformation, pancreatic pseudocysts, duodenal compression, or pancreatogenic portal hypertension.
MRCP provides imaging of the pancreatic duct system and the common bile duct.
ERCP not only shows features such as pancreatic duct dilation or a bead-like appearance but also identifies abnormalities in the pancreatobiliary junction. ERCP can also facilitate ductal brush cytology and drainage.
EUS provides high-resolution images of pancreatic parenchyma and the pancreatic ducts and enables fine-needle biopsy of suspected malignant lesions.
Fecal fat measurement involves a patient consuming 100 g of fat daily for three consecutive days; fecal fat excretion exceeding 7 g/day indicates steatorrhea.
Fecal elastase-1 levels below 200 μg/g suggest pancreatic exocrine insufficiency.
Treatment
Non-Surgical Management
Etiological Treatment
Smoking cessation and abstinence from alcohol are crucial
Pain Management
Nonsteroidal anti-inflammatory drugs (NSAIDs) are considered first. Tramadol or propoxyphene-based analgesics may be used if necessary. Narcotic analgesics are reserved for cases where the aforementioned medications fail to alleviate pain, with careful monitoring to avoid drug dependency.
Dietary Therapy
Small, frequent meals with a diet that is high in protein and vitamins but low in fat are given. Sugar intake is controlled.
Pancreatic Enzyme Supplementation
Exogenous pancreatic enzyme preparations are essential for patients with maldigestion, particularly those with steatorrhea.
Diabetes Management
Blood sugar levels are controlled through dietary adjustments, and insulin replacement therapy may be required.
Nutritional Support
Chronic pancreatitis is often associated with malnutrition. Planned parenteral and/or enteral nutrition support is provided based on the patient's nutritional status.
Surgical Management
The primary objectives of surgical treatment are to alleviate pain and slow disease progression, though the pathological process cannot be reversed. Surgery should be considered early in cases of chronic pancreatitis complicated by biliary obstruction, duodenal obstruction, or suspected malignancy.
Pancreatic Duct Drainage Procedures
The Partington procedure is commonly performed, which involves a longitudinal incision of the pancreatic duct, removal of stones, and side-to-side anastomosis between the pancreatic duct and the jejunum.
Pancreatic Resection
This approach is applicable for patients with severe pancreatic fibrosis without ductal dilation or suspected localized malignancy. The specific surgical procedure depends on the extent and location of the lesion:
- Distal Pancreatic Resection: Indicated for lesions in the pancreatic body and tail.
- Pancreaticoduodenectomy (Whipple Procedure): Indicated for patients with pancreatic head masses, especially those accompanied by biliary or duodenal obstruction.
- Total Pancreatectomy: Reserved for patients with widespread disease and persistent, intractable pain. More than half of patients may achieve pain relief through surgery, but postoperative complications such as diabetes mellitus, steatorrhea, and weight loss may arise. Lifelong insulin therapy and oral pancreatic enzyme supplementation are required.
Combination of Pancreatic Resection and Ductal Drainage
Combined procedures can remove inflammatory lesions in the pancreatic head to relieve pressure on surrounding organs and alleviate pain, while preserving exocrine and endocrine pancreatic function to the greatest extent possible. The continuity of the common bile duct and duodenum is maintained.
Frey procedure involves localized pancreatic head resection combined with longitudinal pancreatic duct drainage and anastomosis to the jejunum.
Berne procedure involves localized pancreatic head resection with jejunal anastomosis at the pancreatic head resection site, without longitudinal pancreatic duct drainage.
Beger procedure involves transverse division at the pancreatic neck with subtotal resection of the pancreatic head. Separate anastomoses are performed for the pancreatic head resection site, distal pancreas, and jejunum.
In addition, for cases of severe refractory pain unresponsive to other methods, procedures such as celiac nerve transection or celiac ganglion ablation may be performed.