Traction-assisted endoscopic ultrasound-guided fine-needle biopsy using the clip-with-thread method for small gastric subepithelial lesions: Randomized controlled trial (with video).

Abstract

Objectives: Endoscopic ultrasound-guided fine-needle aspiration/biopsy (EUS-FNA/B) is the gold standard for diagnosing gastric subepithelial lesions (SELs), but diagnosing lesions smaller than 20 mm remains challenging. We developed traction-assisted EUS-FNB (TA-EUS-FNB) using the clip-with-thread method to enhance diagnostic accuracy by stabilizing the lesion and providing counter-traction for easier needle access. This study evaluates the effectiveness of TA-EUS-FNB in diagnosing small gastric SELs.

Methods: In this prospective, randomized, controlled cross-over trial (August 2019-November 2022), 30 patients with gastric SELs <20 mm were randomized to undergo TA-EUS-FNB or conventional EUS-FNB. Each patient underwent four punctures, two per method. The primary end-point was the adequate tissue sampling rate for both techniques. Secondary end-points included diagnostic yield and performance (sensitivity and specificity) in distinguishing gastrointestinal stromal tumors (GISTs) from non-GISTs.

Results: The mean tumor size was 15.0 mm, with diagnoses comprising GISTs (n = 15, 50%), leiomyomas (n = 8, 26.7%), schwannomas (n = 2, 6.7%), aberrant pancreas (n = 3, 10%), and inflammation (n = 2, 6.7%). TA-EUS-FNB demonstrated a significantly higher adequate-tissue sampling rate (90% vs. 66.7%, P = 0.035) and diagnostic yield (86.7% vs. 63.3%, P = 0.037) than conventional EUS-FNB. Sensitivity (86.7%, 95% confidence interval [CI] 62.1-96.3% vs. 66.7%, 95% CI 41.7-84.8%; P = 0.20) and specificity (100%, 95% CI 79.6-100% vs. 100%, 95% CI 79.6-100%) were comparable between the methods. No adverse events were observed in the study.

Conclusion: TA-EUS-FNB demonstrated superior tissue sampling rates and diagnostic yield for SELs <20 mm compared to conventional EUS-FNB, making it a viable option. Controlling lesion mobility is essential for successful EUS-FNB in small SELs.