Diagnosis and management of chronic pancreatitis: current knowledge

This paper reviews the current literature on chronic pancreatitis (CP). Despite marked progress in diagnostic tools, predominately imaging methods, no consensus has been reached on the nomenclature of CP, ie diagnosis, classification, staging, pathomechanisms of pain and its optimal treatment. A major problem is that no single reliable diagnostic test exists for early-stage CP except histopathology (rarely available). This stage is characterised typically by recurrent acute pancreatitis +/- necrosis (eg pseudocysts). Acute pancreatitis is a well-defined condition caused in 80% of cases by gallstones or alcohol abuse. Alcoholic pancreatitis, in contrast to biliary pancreatitis, progresses to CP in the majority of patients. However, a definite CP-diagnosis is often delayed because progressive dysfunction and/or calcification, the clinical markers of CP, develop on average 5 years from disease onset. The progression rate is variable and depends on several factors eg aetiology, smoking, continued alcohol abuse. Repeated function testing eg by the faecal elastase test, is the best alternative for histology to monitor progression (or non-progression) of suspected (probable) to definite CP. The pathomechanism of pain in CP is multifactorial and data from different series are hardly comparable mainly because insufficient data of the various variables ie diagnosis, classification, staging of CP, pain pattern and presumptive pain cause, are provided. Pain in CP is rarely intractable except in the presence of cancer, opiate addiction or extra-pancreatic pain causes. Local complications like pseudocysts or obstructive cholestasis are the most common causes of severe persistent pain which can be relieved promptly by an appropriate drainage procedure. Notably, partial to complete pain relief is a common feature in 50-80% of patients with late-stage CP irrespective of surgery and about 50% of CP-patients never need surgery (or endoscopic intervention). The spontaneous "burn-out" thesis of CP is in accordance with this observation although precise data of this phenomenon are scarce. Recent observations indicate that the progression to late-stage CP is markedly delayed in non-alcoholic compared to alcoholic CP. Therefore, spontaneous pain relief is also delayed but it occurs in close association with severe exocrine insufficiency suggesting that aetiology has a major impact on the duration of early-stage CP and that the "burn-out" thesis appears valid both in uncomplicated alcoholic and nonalcoholic late-stage CP. For treatment of steatorrhea and diabetes the reader is referred to recent reviews. Mortality and survival are closely related to aetiology with an increased death rate of about 50% within 20 years from onset in alcoholic CP compared to a markedly better prognosis in hereditary and idiopathic "juvenile" CP. The risk of pancreatic cancer is increased particularly in nonalcoholic CP based on the longer survival, whereas the risk of extra-pancreatic (smoking-related) cancer is about 12-fold higher in alcoholic CP.