Chronic Pancreatitis

Chronic pancreatitis is a long-standing inflammation of the pancreas that alters its normal structure and functions. Unlike acute pancreatitis, which involves reversible changes, chronic pancreatitis is characterised by irreversible damage to the pancreas.

The condition can lead to persistent pain, malabsorption, and various complications, including pancreatic cancer. Tobacco smoke and alcohol misuse are the most frequently implicated causes, often having a synergistic effect.

Axial CT showing multiple calcifications in the pancreas in a patient with chronic pancreatitis

Signs and Symptoms

Patients with chronic pancreatitis may present with a range of symptoms, the most common being upper abdominal pain, which typically worsens after eating or drinking but may lessen when fasting or leaning forward. Nausea and vomiting are also prevalent. Due to reduced production of pancreatic enzymes, malabsorption can occur, leading to steatorrhea, which involves frequent, oily, foul-smelling bowel movements. Weight loss is common even with normal eating habits. Additionally, chronic pancreatitis can impair insulin production, leading to Type 3c diabetes, which is characterised by symptoms such as increased hunger and thirst, frequent urination, weight loss, fatigue, and blurry vision.

Causes

The most common causes of chronic pancreatitis include chronic alcohol misuse and smoking. Genetic factors account for approximately 10% of cases, involving mutations in genes like CFTR, SPINK1, and CTRC. Chronic pancreatitis can also be idiopathic, autoimmune, or due to intraductal obstruction, tumours, ischaemia, or calcific stones. Hereditary pancreatitis, which involves a mutation of the Trypsin 1 gene, is less common but notable.

Pathophysiology

PRSS1

The pathophysiology of chronic pancreatitis often involves genetic mutations, such as in the PRSS1 gene, which can lead to early onset of severe epigastric pain. Environmental factors like alcohol, malnutrition, and smoking also play significant roles. Chronic inflammation leads to fibrosis, calcification, and atrophy of the pancreas, disrupting its exocrine and endocrine functions.

Diagnosis

Diagnosis of chronic pancreatitis is based on clinical history, symptomatology, and radiologic imaging. Serum amylase and lipase levels may be moderately elevated. Symptoms like oily, bulky, and foul-smelling stools indicate steatorrhea and can be confirmed by checking faecal elastase levels or a quantitative faecal fat test. Genetic causes may be identified through elevated ESR, IgG4, rheumatoid factor, ANA, and anti-smooth muscle antibody levels. Imaging techniques such as CT scans, MRCP, and EUS are employed to detect calcifications, ductal changes, and atrophy. MRI scans may reveal a low T1 signal, indicating inflammation and fibrosis.

Treatment

Treatment for chronic pancreatitis includes medical measures, therapeutic endoscopy, and surgery. Pain management is very important and often requires analgesics, including opiates, pregabalin, gabapentin, tricyclic antidepressants, and SNRIs. Abstaining from alcohol and smoking is essential. Antioxidants may offer some benefit, although their efficacy is uncertain. Endoscopic treatments, such as stone removal and ductal dilation, may be employed. Extracorporeal shockwave lithotripsy can also be used to break down pancreatic stones.

Pancreatic Enzymes

Pancreatic enzyme replacement therapy is effective for treating malabsorption and steatorrhea. Administering a solution of pancreatic enzymes with meals can reduce symptoms and improve nutritional status. Enzyme replacement may also alleviate pain, particularly in patients without large duct involvement.

Surgery

Surgical options for chronic pancreatitis include resectional and drainage procedures. Indications for surgery include pseudocysts, fistulas, ascites, or fixed obstructions. Procedures such as the Puestow procedure, pancreaticoduodenectomy, and total pancreatectomy may be performed, depending on the patient's condition and response to other treatments.

Epidemiology

The annual incidence of chronic pancreatitis ranges from 5 to 12 per 100,000 persons, with a prevalence of 50 per 100,000. Environmental factors, including radioactive cesium contamination, may contribute to the development of chronic pancreatitis and pancreatic cancer.

Self-assessment MCQs (single best answer)

What is the primary distinguishing feature between acute and chronic pancreatitis?

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Which two lifestyle factors are most frequently implicated in the development of chronic pancreatitis?

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Which symptom is commonly associated with chronic pancreatitis and is characterised by frequent, oily, foul-smelling bowel movements?

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What type of diabetes is commonly associated with chronic pancreatitis?

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Which gene mutation is associated with hereditary pancreatitis?

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What imaging technique is frequently used to detect calcifications, ductal changes, and atrophy in chronic pancreatitis?

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Which treatment is effective for alleviating malabsorption and steatorrhea in patients with chronic pancreatitis?

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What is the annual incidence of chronic pancreatitis per 100,000 persons?

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Which surgical procedure may be performed for chronic pancreatitis and involves the drainage of the pancreatic duct?

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Which of the following is a genetic test marker that may be elevated in cases of autoimmune chronic pancreatitis?

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