A prospective study on the histological evaluation of type 1 autoimmune pancreatitis using endoscopic ultrasound-guided fine needle biopsy with a 19-gauge Franseen needle

Background/Purpose

To assess the diagnostic efficacy and safety of endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) using a 19-gauge Franseen needle for autoimmune pancreatitis (AIP).

Methods

Twenty patients suspected of having type 1 AIP were prospectively enrolled and underwent EUS-FNB with a 19-gauge Franseen needle. Their data were compared with those of historical controls: a total of 29 type 1 AIP patients had EUS-FNB with a 22-gauge Franseen needle.

Results

Specimens suitable for histological evaluation were obtained from 19 of the 20 patients (95%), and the median total tissue area was 11.9 mm². The histological diagnosis rate of AIP was 65% (95% CI: 43.2%–82%). Adverse events were observed in three patients (15%), and a switch to 22-gauge needles occurred during transduodenal puncture in two patients. Compared to those punctured with 22-gauge needles, patients punctured with 19-gauge needles had greater prevalence of each characteristic feature of lymphoplasmacytic sclerosing pancreatitis, but the difference was not statistically significant.

Conclusions

EUS-FNB using a 19-gauge Franseen needle demonstrated favorable performance for the histological diagnosis of AIP and allowed for large tissue samples, potentially facilitating pathological diagnosis. However, during transduodenal puncture, maneuverability is reduced; therefore, the needle may need to be selected according to the puncture site.