7Endosonography in the management of biliopancreatic disorders
Section snippets
Detection, diagnosis and staging of mass lesions
Patients who present with symptoms of a suspicious hepatopancreatobiliary malignancy need extensive evaluation to examine the nature of a potential lesion and to determine its resectability. For this, endosonography (EUS) has proved to be a valuable technique for detection, diagnosis and staging of pancreatic, ampullary and bile duct cancer.
Detecting bile duct stones
Nowadays, ERCP is considered to be a therapeutic investigation because of its risk for complications [35]. Consequently, patients with an intermediate or low pre-test probability of having common bile duct stones (CBDSs) would benefit from a diagnostic test that does not expose them to risk, but reliably sets an indication to proceed to ERCP. Barkun et al proposed a model to calculate the pre-test probability of CBDS involving age, bilirubin level and data from trans-abdominal US [36]. When the
Pancreatic cysts
EUS can be very helpful in the differential diagnosis of pancreatic cysts. Pancreatic cysts are divided in non-neoplastic and neoplastic cysts. The former cysts may arise in the course of acute or chronic pancreatitis and have no malignant potential. Neoplastic cysts, however, depending on their origin, do have a malignant potential and are important to diagnose to direct further management, including pancreatic resection. Neoplastic cysts include, for example, mucinous cystadenoma (MCN) and
Chronic pancreatitis
EUS is sensitive to subtle changes that may be associated with ‘early’ chronic pancreatitis (CP). The diagnosis of CP by EUS depends on the presence or absence of multiple EUS criteria of CP. The first diagnostic EUS criteria of CP were suggested by Lees et al in 1979 [53]. In 1993, these criteria were refined by Wiersema et al and these comprised parenchymal EUS features (including (1) echogenic foci, (2) focal regions of reduced echogenicity (strands) and (3) increased parenchymal lobularity)
Interventional EUS for pancreatobiliary disease
With the introduction of curvilinear-array echoendoscopes, EUS has turned from a solely observational diagnostic tool into an advanced interventional technique offering the possibility to not only acquire tissue samples for diagnostic purpose by means of FNA, but also to introduce, for example, drugs by fine-needle injection (FNI). Furthermore, various accessories such as guide wires can be advanced through a needle into a target structures to carry out EUS-guided cyst, biliary and pancreatic
Conclusion
EUS has proved to be a valuable tool in the diagnosis and treatment of biliopancreatic diseases. With the ongoing developments in cross-sectional imaging, including MD-CT and magnetic resonance imaging, diagnostic indications for EUS may decline, although its ability to acquire instant tissue samples remains appealing and of great clinical use. Undoubtedly, applications of interventional EUS will further evolve and develop to aid in the management of patients with complex biliary and pancreatic
Conflict of interest
None.
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