Published online Oct 7, 2020. doi: 10.3748/wjg.v26.i37.5693
Peer-review started: July 29, 2020
First decision: August 8, 2020
Revised: August 21, 2020
Accepted: September 15, 2020
Article in press: September 15, 2020
Published online: October 7, 2020
Endoscopic ultrasound-guided tissue acquisition (EUS-TA) is an established modality for the evaluation of pancreatic lesions. Recently fine needle biopsy (FNB) has been introduced in order to obtain samples with preserved tissue architecture. Studies evaluating one of the most recent introduced FNB needles, the Franseen needle, have shown very promising results of high histological tissue acquisition rate.
So far there is little evidence about the performance of the Franseen needle in the evaluation of pancreatic lesions, when applying a standardised protocol of a predetermined low number of needle passes, without access to an on-site cytopathologist and flushing out the obtained material direct into formalin.
We performed a prospective, single-arm study to evaluate the clinical performance of the 22-gauge (22G) Franseen needle, when sampling pancreatic lesions according to a standardised protocol, focusing on the quality of the acquired histological specimens.
Consecutive patients with an indication for EUS-FNB for the assessment of pancreatic lesions from June 2017 to December 2018 underwent a puncture of the lesion two times using the 22G Franseen needle in our department. The obtained material was treated like a biopsy specimen, placed directly into formalin, completely embedded in paraffin and cut to provide heamatoxylin-eosin stained sections for histological analysis. Our primary endpoint was the acquisition rate of high-quality histological specimen, regarded by the pathologist as representative (Payne score 3). Secondary endpoints were size of the core specimen, the diagnostic accuracy and the complication rate. The gold standard for definite diagnosis was considered one or more of the following: A definite histology obtained from EUS-FNB, a surgical resection or clinical follow-up up to twelve months.
Forty patients with a mean age of 67.2 years were included in this study. Tissue acquisition was achieved in all cases, whereas high-quality histology, rated with Payne score 3, was obtained in 37 out of 40 cases (92.5%). A correct diagnosis (diagnostic accuracy) was made in 34 out of 40 cases (85%). The final diagnosis was confirmed based on definite EUS-FNB histology in 21 patients, on surgical resection in 8 patients, on both definite EUS-FNB and surgery in 5 further patients and on interval follow-up in 6 patients. The only complication occurred was a self-limiting bleeding in the puncture site.
We demonstrated that EUS-FNB of pancreatic lesions with the 22G Franseen needle following a standardised simplified protocol achieved a high acquisition rate of representative histological specimen and a high diagnostic accuracy.
We consider that further prospective studies with a standardised protocol of a predetermined low number of needle passes are required to draw a conclusion about the need of ROSE.