Superiority of Linear-Array EUS over MRCP in Diagnosing Pancreas Divisum: Evidence from a Multicenter Retrospective Study in Oriental Cohorts

Background and aims: Pancreas divisum (PD) is the most common developmental anatomic variant of pancreatic duct. The published data on the accuracy of the detection of pancreas divisum by linear-array endoscopic ultrasound (L-EUS) is limited. The current study aimed to assess the diagnostic accuracy of L-EUS compared with magnetic resonance cholangiopancreatography (MRCP) for identifying PD.

Methods: Patients who underwent linear-array EUS for pancreaticobiliary indications and subsequently received endoscopic retrograde pancreatograghy (ERP) treatment were retrospectively evaluated between January 2019 and July 2023.

Results: A total of 1378 patients from three tertiary centers were included, out of which 120 were diagnosed with pancreas divisum (PD), as confirmed by ERP, yielding an endoscopic detection rate of 8.7%. L-EUS exhibited a high sensitivity of 90.8% (95% confidence interval [CI], 85.7%-96.0%) and an overall accuracy of 99% (95% CI, 98.5%-99.5%) for the diagnosis of PD. These figures were significantly superior to those of MRCP, which showed a sensitivity of 48.4% (95% CI, 38.1%-58.6%) and an accuracy of 95.4% (95% CI, 93.5%-96.3%) (P < 0.001). Furthermore, the area under the curve (AUC) for PD diagnosis was notably higher for L-EUS (95.7%) compared to MRCP (74.1%) (P < 0.001). Consistency testing revealed that L-EUS had an excellent kappa (κ) value of 0.934, compared to the reference standard of 0.621. Univariate logistic regression analysis identified the presence of pancreatic duct stones, chronic pancreatitis, and severe pancreatitis as potential factors leading to diagnostic failure of in detecting PD with L-EUS. Subsequent multivariate logistic regression analysis confirmed the presence of pancreatic duct stones (odds ratio [OR] 5.627, 95% CI, 1.391-22.765) and severe pancreatitis (OR 12.818, 95% CI, 2.280-72.061) were significantly associated with increased odds of L-EUS diagnostic failure for PD.

Conclusions: Our study conclusively demonstrates that L-EUS significantly outperforms MRCP in diagnosing pancreas divisum. L-EUS exhibits markedly higher sensitivity, and area under the curve (AUC) values. However, its diagnostic reliability decreases in the presence of pancreatic duct stones or severe pancreatitis.