The Role of Endoscopic Ultrasound in Early Chronic Pancreatitis

Chronic pancreatitis (CP) is an irreversible and progressive inflammation of the pancreas that can involve both pancreatic parenchyma and the pancreatic duct. CP results in morphological changes in the gland in the form of fibrosis and calcification along with functional impairment in the form of exocrine and endocrine insufficiency. Studies on the natural history of CP reveal the irreversibility of the condition and the resultant plethora of complications, of which pancreatic adenocarcinoma is the most dreaded one. In Japanese population-based studies by Otsuki and Fuzino et al., CP was clearly shown to reduce lifespan among males and females by 10.5 years and 16 years, respectively. This dismal prognosis is superadded to significant morbidity due to pain and poor quality of life, creating a significant burden on health and health-related infrastructure. These factors have led researchers to conceptualize early CP, which, theoretically, is a reversible stage in the disease spectrum characterised by ongoing pancreatic injury with the presence of clinical symptoms and the absence of classical imaging features of CP. Subsequently, the disease is thought to progress through a compensated stage, a transitional stage, and to culminate in a decompensated stage, with florid evidence of the functional impairment of the gland. In this focused review, we will discuss the definition and concept of early CP, the risk factors and natural history of the development of CP, and the role of various modalities of EUS in the timely diagnosis of early CP.