ERCP-Based Cell Block: A Potential One-Stop Shop in the Management of Malignant Biliary Obstruction

Area of Science:

• Gastroenterology and Hepatology
• Oncology
• Diagnostic Cytopathology

Background:

• Malignant biliary obstruction (MBO) often presents at advanced stages, necessitating accurate diagnosis.
• Current diagnostic methods like ERCP and EUS-FNA have limitations in accuracy and cost.
• Pancreatic adenocarcinoma, cholangiocarcinoma, and gallbladder carcinoma are common causes of MBO.

Purpose of the Study:

• To compare the diagnostic accuracy of cell block (CB) cytology during ERCP-guided stenting versus traditional EUS-FNA for unresectable MBO.
• To evaluate the cost-effectiveness of CB cytology compared to EUS-FNA.
• To assess the combined diagnostic yield of both methods.

Main Methods:

• A prospective observational study of 102 patients with advanced unresectable MBO.
• Patients underwent both EUS-FNA and ERCP-guided stenting with CB sampling.
• Diagnostic yield and cost-effectiveness analysis were performed for CB alone, EUS-FNA alone, and combined strategies.

Main Results:

• EUS-FNA had a higher diagnostic yield (82.35%) than CB (72.54%), not statistically significant.
• Combined EUS-FNA and CB significantly increased diagnostic yield to 93.13% (p=0.04).
• CB showed superior performance in direct biliary invasion (88.23% vs. 79.41%, p=0.01) and offered a cost reduction of 319.17 € per case.

Conclusions:

• EUS-FNA is superior for extrinsic MBO, but ERCP-based CB is a cost-effective option for biliary tract cancers.
• Concurrent use of EUS-FNA and CB enhances diagnostic accuracy, optimizing costs in specific scenarios.
• The study supports the combined approach for improved diagnosis and cost efficiency in managing MBO.