# Evaluation of a Novel Tapered Tip EUS-FNB Needle: A UK Multicentre Study

## TL;DR

This study compares a new tapered tip EUS-FNB needle with traditional needles for diagnosing pancreatic and biliary tumors, finding similar accuracy and sensitivity.

## Contribution

This is the first and largest study evaluating the diagnostic performance of a novel tapered stylet EUS-FNB needle in a multicenter UK setting.

## Key findings

- The tapered stylet needle showed comparable sensitivity (90% vs. 88%) and diagnostic accuracy (92.2% vs. 91.5%) to conventional needles.
- No significant differences were observed in malignancy diagnosis outcomes between the two needle types.
- The study is the first to report on the performance of the new tapered stylet needle in clinical practice.

## Abstract

Endoscopic ultrasound fine needle biopsy (EUS FNB) is the investigation of choice for pathological diagnosis of pancreaticobiliary solid tumours. In the era of precision oncology, tissue samples of sufficient volume and quality are required to enable next-generation sequencing and ancillary studies. A novel tapered stylet FNB needle has recently been introduced for EUS FNB with the aim of improved tissue acquisition, but to date, there are no comparative data available in the literature. The present study investigated the performance of this new FNB needle across several tertiary HPB centres in the UK. We compared outcomes to a similarly matched cohort that underwent sampling using legacy FNB needles as a control arm. We collected data for 129 patients using the novel tapered tip FNB needle and 141 control cases. Both groups demonstrated a high sensitivity and accuracy for the diagnosis of malignancy, with no significant difference in outcomes. This is the first study we are aware of reporting outcomes for the new tapered stylet FNB needle.

Introduction: A new core biopsy needle with a novel tapered stylet tip has been introduced for endoscopic ultrasound-guided fine needle biopsy (EUS-FNB). The tapered point stylet is purported to improve ease of puncture, leading to improved tissue acquisition and accuracy. However, there are no data available in the published literature. The aim of this study was to compare the diagnostic performance of the tapered stylet needle with conventional end-cutting FNB needles for tissue acquisition from solid lesions. Methods: Patients who underwent EUS-FNB of a solid lesion using the tapered stylet FNB needle across four tertiary hepatopancreaticobiliary centres in the UK were included in the study. Demographic, clinical, and performance outcomes were included in the analysis. Diagnostic performance was compared with a similar cohort of patients who underwent EUS-FNB using standard end-cutting FNB needles with a blunt-tipped stylet. The primary outcome was accuracy for the diagnosis of malignancy. Results: A total of 270 patients were included for analysis; 129 patients (48%) had sampling with the novel tapered stylet tip needle, among which 50% were female, the median age was 69, 74% had pancreatic lesions, and 80% had a final diagnosis of malignancy; 141 control cases (52%) were included for comparison, among which 48% were female, the median age was 68, 67% had pancreatic lesions, and 72% had a final diagnosis of malignancy. The tapered stylet needle demonstrated a sensitivity of 90% and an NPV of 72% for the diagnosis of malignancy compared with 88% and 77% for controls (p = 0.147). The overall diagnostic accuracy of the tapered stylet needle was 92.2% compared with 91.5% for controls (p = 0.634). Conclusions: The novel tapered tip stylet FNB needle demonstrated comparable sensitivity, NPV, and diagnostic accuracy to conventional FNB needles. This is the first and largest study reporting results for this new needle. However, further large comparative studies are warranted to validate our results and to determine if the tapered stylet offers an advantage over the conventional design.