Aims The actual efficacy of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA)
in practice depends on the site, size, characteristics of the target tissue, as well
as the availability of a cytopathologist to render an on-site diagnosis [1]
[2]. Fine-needles designed to obtain biopsy (FNB) specimens allow core samples to be
collected by shearing tissue from the target lesion. This is a novel motorized EUS-FNB
(mFNB) which enables increased yield, bigger sample size retrieval with improved quality
and fewer needle passes, providing tissue with conserved architecture and less blood
contamination, enabling a better histological analysis. We aim to evaluate the safety,
efficacy and comfortability of the mFNB and compare its performance to a standard
FNB (sFNB).
Methods A single-center, prospective, pilot study performed in patients that required EUS-guided
biopsy from September 2023 to November 2024. Patients scheduled for EUS-FNB, including
patients with submucosal lesions, mediastinal masses, lymphatic nodes, pancreatic
cancer and intraperitoneal masses, who were at least 18 years old.
Results Forty participants were included in the study, mean age was 65,0 (57.8 – 69.2) and
57.5% were female. Most biopsies were liver biopsies (55%), mean number of stabs was
4 (± 2). A mild adverse event (mucosal laceration) was reported with mFNB (2.5%).
The mFNB obtained a 97.5% technical success. Biopsy was definitive in 95.0% with two
cases reporting inadequate samples. When comparing mFNB vs sFNB performance: mFNB
blood contamination was reported as lower than 25% in 90% of cases, while 72.5% of
sFNB samples reported moderate contamination (50% of blood contamination in histological
slides). Both FNBs obtained architecturally intact tissue samples in 95% of cases;
however, 87.5% of mFNB had a piece of at least 550μm, while sFNB 2.5%. 65% of mFNB
samples were multiple fragments with at least one>5mm in length (42.3% at least one
fragment>10mm); 52.5% of sFNB samples were>5mm in length (2.5% had one fragment>10mm).
A median number of portal triads observed 6 (4-8) with mFNB, and 2 (0.5-2.75) with
sFNB. Comfortability of the mFNB was evaluated using a 5-Point Likert Scale, considering
the following: determining a preferred sheath length by adjusting the sliding sheath
adjuster, comfortable to adjust the stopper lock position, comfortable to advance
the needle into the lesion, comfortable to withdraw the stylet, comfortable to sample
tissue by pushing the sampling button, comfortable to expel the biopsy sample. All
parameters obtained a high agreement (> 95%).
Conclusions mFNB is safe and efficient to perform during EUS-FNB, with low adverse event rates
and high technical success. Operators indicated high clinical expectations and comfortability
regarding the different components of the needle. mFNB obtained larger tissue samples
with less blood contamination compared to sFNB.
