Aims Endoscopic ultrasound-guided fine needles biopsy (EUS-FNB) is considered essential
for the assessment of solid pancreatic lesions (SPLs) in the current personalized
medicine era. Despite the advantages in tissue acquisition due to the newest generation
of FNB needles, many aspects still require technical standardization, above all the
right number of needle passes to obtain adequate histological characterization and
optimal core for molecular analysis due to the newest therapeutic interest for the
microsatellite instability in pancreatic ductal adenocarcinoma. In our study we aim
to evaluate if less than 3 passes are enough to ensure high rates of confirmed histological
diagnosis with the newest generation of FNB cutting needles.
Methods Patients with SPLs requiring tissue sampling through EUS were retrospectively enrolled
in our study, since a new 22G needle with asymmetric three-prong tip has been introduced
in our center, between September 2022 and September 2023. Tissue sampling was performed
using the slow-pull technique and fanning when possible. The number of needle passes
was determined by the macroscopic onsite evaluation (MOSE) and samples, coming from
different passes, were divided into different test tubes. Our evaluation included
diagnostic accuracy, positive core procurement yield and sample quality considering
each test tube separetely.
Results 79 lesions (of which 73% pancreatic ductal adenocarcinoma) were sampled with an average
size of 32 mm (SD=11mm). Sampling was performed with 2 or 3 passes, according to MOSE.
Regarding the first needle pass, diagnostic accuracy was 92.41% which reached 94.94%
considering the second pass (75 confirmed histological diagnosis) and it was not influenced
by the third pass. Sample adequacy reached approximately 99% and positive core procurement
and tissue quality were>95% in all test tubes. In all histologically confirmed pancreatic
adenocarcinomas, the material obtained through 2 needle passes, was sufficient for
the assessment of immunohistochemistry for mismatch repair proteins. No major adverse
events were registered.
Conclusions In patients with SPLs, the newest generation of histology needles for EUS-FNB could
ensure a high diagnostic accuracy for both histological and molecular characterization
with two needle passes, becoming extremely relevant in terms of time-saving, cost-effectiveness
and safety, especially in high volume centers. Due to the limited number of patients
additional data are needed.
