EUS and MRCP as complementary studies in the etiologic diagnosis of idiopathic acute pancreatitis

Background: Approximately 10%-30% of patients with acute pancreatitis do not have an established etiology after routine investigation with imaging. These patients are classified as IAP. Less invasive tests, such as EUS, MRCP, and secretin stimulation MRCP (S-MRCP) have been used to further explore IAP, but their comparison in the etiologic diagnosis of idiopathic acute pancreatitis is lacking.

Study design: Meta-analysis involving 34 studies that investigated the etiology of IAP with MRCP and/or S-MRCP and/or EUS.

Setting: Brazil, Canada, China, France, Hong Kong, India, Italy, Korea, Spain, the United Kingdom, and the United States.

Synopsis: When EUS was compared with MRCP, the diagnostic yield of EUS (153/239 patients; 64%) was higher than that of MRCP (82/238 patients; 34%; P less than .01). Specifically, EUS seemed to have a significant benefit in detecting biliary disease, compared with MRCP. In the subgroup analysis, the diagnostic yield of EUS was higher than that of MRCP for detecting parenchymal changes suggestive of chronic pancreatitis (10% vs. 1%). S-MRCP was superior to EUS and MRCP (12% vs. 2% vs. 2%, respectively) in diagnosing pancreatic divisum, a congenital anomaly that is prevalent in 5%-14% of the population and an etiology of IAP.

A limitation in this meta-analysis was that EUS was used in seven times as many studies as was MRCP, which may have influenced the overall results.

Bottom line: Less invasive modalities, such as EUS and S-MRCP, used together could improve the diagnostic yield in evaluating the etiology of AIP.

Citation: Wang J et al. Comparison of EUS with MRCP in idiopathic acute pancreatitis: A systemic review and meta-analysis. Gastrointest Endosc. 2017 Dec 7. doi: 10.1016/j.gie.2017.11.028.