Endoscopic Ultrasound-Guided Tissue Acquisition Using Fork-Tip Needle for Subepithelial Lesions: A Single-Center Validation Study.

Background: The cutoff value for stereomicroscopic on-site evaluation (SOSE) in endoscopic ultrasound-guided tissue acquisition (EUS-TA) has high diagnostic sensitivity when a Franseen needle is employed for upper gastrointestinal subepithelial lesions (SELs) (stereomicroscopically visible white core [SVWC] ≥ 4 mm).

Aim: We aimed to determine whether high diagnostic sensitivity could be obtained when EUS-TA was performed using a Fork-tip needle.

Methods: Twenty-one patients were prospectively registered. Patients underwent EUS-TA using a Fork-tip needle for upper gastrointestinal SELs at Kitasato University Hospital between January and November 2022. Punctures were made twice using the needle, and SOSE was conducted for each specimen. Blood and physical examination were performed to assess adverse events. Pathological diagnosis was made using hematoxylin and eosin-stained sections and immunohistochemical staining. Statistical comparisons were completed using Fisher's exact tests.

Results: The diagnostic rate of EUS-TA was 100% (21/21 cases). The final diagnosis was gastrointestinal stromal tumor in 17 (81.0%) and leiomyoma in 4 (19.0%) patients. SOSE was conducted on all 42 punctures, and the tissue sampling rate was 100% (42/42 punctures). Specimens with SVWC ≥ 4 mm were collected in 97.6% punctures (41/42 punctures) and the diagnostic sensitivity for these specimens was 100% (41/41 punctures), which is significantly higher (p < 0.0238) compared to the absence of cutoff value (diagnostic sensitivity of 0%). No EUS-TA-related adverse events occurred.

Conclusions: EUS-TA combined with SOSE for upper gastrointestinal SEL using a fork-tip needle had a high diagnostic rate, and the cutoff value of SVWC ≥ 4 mm had high diagnostic sensitivity.