# A99 INCREASING THE NUMBER OF PASSES FOR ENDOSCOPIC ULTRASOUND-GUIDED FINE NEEDLE ASPIRATION BIOPSY OF SOLID MASS LESIONS – A QUALITY IMPROVEMENT INITIATIVE TO IMPROVE DIAGNOSTIC YIELD

## TL;DR

Increasing the number of needle passes during endoscopic ultrasound-guided biopsies improves diagnostic accuracy for solid mass lesions.

## Contribution

A quality improvement initiative demonstrated that increasing needle passes from one to three or more improves diagnostic yield.

## Key findings

- A single needle pass had a diagnostic yield of 56%, similar to pre-intervention results.
- Increasing to three or more needle passes improved diagnostic yield to 90%.
- Education and audit led to a shift from single to multiple passes over time.

## Abstract

A retrospective chart audit (01/2022-12/2022) of endoscopic ultrasound (EUS)-guided fine needle aspiration biopsy (FNAB) of solid mass lesions revealed a disappointing diagnostic yield of 56% with a single needle pass. To improve this, a quality improvement (QI) intervention where endoscopists (three) were encouraged to perform three needle passes per patient was developed and trialed.

To assess intervention impact on improving the diagnostic yield of EUS-FNAB of solid mass lesions over a 9-month study period.

A chart audit was completed quarterly for all patients undergoing EUS-FNAB of solid mass lesions from 01/2024-09/2024. Descriptive statistics were completed. Only a definite diagnosis, as confirmed on histological examination, was considered when calculating the diagnostic yield.

A total of 183 patients (112 M, 71 F), mean age 63±13 years (range 12-88 years), underwent 198 EUS-FNABs by 3 endoscopists over 9 months. A single pass with an FNAB needle was undertaken in 36/198 cases (18%). The diagnostic yield was 20/36 (56%), similar to the pre-intervention year. The solid mass lesions targeted were pancreas (16), lymph nodes (12), subepithelial (3), rectal and retro-peritoneal (2 each), and ampulla (1). One endoscopist performed 25/36 cases (69%) whereas the other two performed 11/36 (31%) and 0/36 cases. Proximity to vasculature and technical difficulty were reasons provided in 11 and 1 case(s), respectively, whereas no reason was documented in 24 cases. There was no difference in these variables between the groups with a definite diagnosis (20/36) vs. those without (16/36). After the first quarter audit, the need to avoid a single needle-pass was reinforced. Figure 1 shows the trend of single vs. 3 or more needle passes for the pre-intervention vs. the post-intervention year. There is a trend towards performing fewer single needle passes (39 pre vs. 36 post) and increasing 3 or more needle passes (25 pre vs. 68 post). This was associated with an improvement in diagnostic yield in the pre (22/39 [56%] vs. 21/25 [84%]) vs. post groups (20/36 [56%] vs. 61/68 [90%]).

Education, regular audit, and continued reinforcement has demonstrated an improvement in the diagnostic yield of EUS-FNAB by increasing the number of needle passes to 3 or more for solid mass lesions.

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