Endoscopic Ultrasound-guided Fine-Needle Biopsy With End-Cutting Needles in Autoimmune Pancreatitis: A Systematic Review and Meta-Analysis.

[OBJECTIVES] There is limited evidence on the diagnostic yield of endoscopic ultrasound (EUS)-guided tissue acquisition (TA) using fine-needle biopsy (FNB) in autoimmune pancreatitis (AIP), particularly considering the newer end-cutting needles. The aim of this meta-analysis was to provide a pooled estimate of the diagnostic performance of EUS-TA using FNB in AIP patients according to the needle type used.

[METHODS] A computerized bibliographic search was performed through April 2024. Pooled effects were calculated using a random-effects model. The primary endpoint was diagnostic accuracy. Secondary outcomes were sample adequacy, rates of adequate material for levels 1 and 2 of histological diagnosis, definitive diagnosis reached with histology in addition to imaging/laboratory tests, and safety.

[RESULTS] Twelve studies (three prospective series and one randomized trial) with 496 patients were included. Overall diagnostic accuracy rate was 75% (66%-83%), with a superiority of end-cutting needles over reverse bevel needles (80%, 70%-90% versus 49%, 21%-67%; < 0.001). Franseen (81%, 68%-93%) and Fork-tip needles (86%, 74%-98%) showed the highest accuracy. Sample adequacy rate was 92% (87%-98%), and EUS-TA using FNB provided level 1 of histological diagnosis in 47% of cases (38%-57%) and level 2 in 23% (16%-30%). EUS-TA using FNB provided a definitive diagnosis in 77% (63%-91%) of cases. Pooled rate of adverse event was 2% (1%-3%), mainly mild pancreatitis.

[CONCLUSIONS] End-cutting needles showed high diagnostic yield in patients with AIP, with a low rate of adverse events, and should be preferred over reverse bevel needles.