Introduction

Current endoscopic ultrasound technologies (EUS) are suboptimal in the assessment of pancreatic cystic lesions (PCLs). We developed a new through-the-needle brush, the "loop brush", to improve the cellular yield, and thereby sensitivity, of EUS fine needle aspiration (EUS-FNA) of pancreatic cysts.

Aims & Methods

We aim to evaluate the "loop brush" safety, robustness, and efficacy.
We performed an in-vivo randomized controlled trial in pigs using artificial cysts. In one group, the loop brush was deployed through a 22G EUS-FNA needle into the cysts. In the control group, cystic punction was performed with standard EUS-FNA. Loop brushes were visually inspected post-procedure. Cytological assessment, cell counting, and hemoglobin analysis were performed in samples from both groups.

Results

Artificial cysts (n=114) were punctured in six pigs, 57 in each group. Neither adverse events nor significant device malfunction occurred during loop brushing. Samples collected with the brush had non-detectable concentrations of hemoglobin in 72% (41/57) of cases, and 26% (16/57) had less than 0.6 g/dL, with no significant difference to the controls (p=0.32). Brushing cell counts were associated with significantly increased cell counts (11.7× median difference, p<.0001). Cytological smears
were diagnostic in 77% of cases in the brushing group, while 54% in the control group (p=0.01, Fisher’s exact test; p=0.006, Chi-square test).

Conclusion

The new loop brush procedure appears to be safe, causing neither significant bleeding nor device malfunction. Samples obtained with the loop brush were suitable for cytological analysis and showed significantly higher cell yield than controls. Further clinical studies are warranted.

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Disclosure

FM, WW, UA, NR, and FBS have patent applications for the brush technology and are co- founders of Lucky LoopMedical AB, a company commercializing technology for improved sampling in EUS-FNA. UA has received a research grant from Boston Scientific and is a consultant to Boston Scientific, Medtronic, and Ambu. IS declares no conflict ofinterest.