Endoscopic ultrasound in chronic pancreatitis: where are we now?

Abstract

Endoscopic ultrasonography (EUS) is well suited for assessment of the pancreas due to its high resolution and the proximity of the transducer to the pancreas, avoiding air in the gut. Evaluation of chronic pancreatitis (CP) was an early target for EUS, initially just for diagnosis but later for therapeutic purposes. The diagnosis of CP is still accomplished using the standard scoring based on nine criteria, all considered to be of equal value. For diagnosis of any CP, at least three or four criteria must be fulfilled, but for diagnosis of severe CP at least six criteria are necessary. The Rosemont classification, more restrictive, aims to standardize the criteria and assigns different values to different features, but requires further validation. EUS-fine needle aspiration (EUS-FNA) is less advisable for diagnosis of diffuse CP due to its potential side effects. Elastography and contrast-enhanced EUS are orientation in differentiating a focal pancreatic mass in a parenchyma with features of CP, but they cannot replace EUS-FNA. The usefulness of EUS-guided celiac block for painful CP is still being debated with regard to the best technique and the indications. EUS-guided drainage of pseudocysts is preferred in non-bulging pseudocysts or in the presence of portal hypertension. EUS-guided drainage of the main pancreatic duct should be reserved for cases in which endoscopic retrograde cholangiopancreatography has failed owing to difficult cannulation of the papilla or difficult endotherapy. It should be performed only by highly skilled endoscopists, due to the high rate of complications.

Figures

Figure 1

Flowchart of the endoscopic ultrasonography utility in chronic pancreatitis. EUS: Endoscopic ultrasonography; CP: Chronic pancreatitis; CE-EUS: Contrast enhanced endoscopic ultrasonography; MPD: Main pancreatic duct.

Figure 2

Chronic pancreatitis. Parenchymal and ductal pancreatic stones as hyperechoic structures with shadowing and stenosis of the main pancreatic duct.

Figure 3

Mass resembling chronic pancreatitis. A: Conventional endoscopic ultrasonography (EUS). Hypoechoic inhomogeneous mass in the pancreatic head. Aorta and inferior caval vein are also seen; B: Contrast-enhanced harmonic-EUS. During the arterial phase (25 s after contrast injection) the abdominal aorta becomes hyperechoic and the mass is hypovascular compared with surrounding parenchyma.

Figure 4

Endoscopic ultrasonography-guided pseudocyst drainage. A: The cystostomy is seen as a hyperechoic parallel structure inside the hypoechoic well-delineated pseudocyst; B: Endoscopic view of a stent and a nasocystic drainage placed transgastric into a pseudocyst.