BACKGROUND: Endoscopic ultrasound (EUS)-guided tissue acquisition has become the most effective method of obtaining specimens from a solid lesion adjacent to the gastrointestinal tract. No data exist regarding the use of a stylet in the core biopsy needle during EUS-guided tissue acquisition. The aims of this study were to evaluate the feasibility, safety, and diagnostic yield of a 25-gauge core biopsy needle without (S-) a stylet and to compare its performance with that of a 25-gauge core biopsy needle with (S+) a stylet in patients with solid lesions adjacent to the gastrointestinal tract.
METHODS: From November 2013 to January 2016, we performed 114 EUS-guided tissue acquisitions for the diagnosis of solid lesions adjacent to the gastrointestinal tract in a randomized controlled trial. Patients were randomly assigned to the S+ group (n = 57) or the S- group (n = 57). EUS-guided tissue acquisition was performed using a 25-gauge core biopsy needle without an on-site cytopathologist.
RESULTS: There were no significant differences in technical success (100 vs. 100%, p = 1.000), the mean number of needle passes (7.0 +/- 1.6 vs. 6.8 +/- 1.5, p = 0.556), needle malfunction (0 vs. 1.8%, p = 1.000), or complications (1.8 vs. 0%, p = 1.000) between the S+ and S- groups. Both groups exhibited comparable outcomes with respect to cytological diagnostic accuracy (93.0 vs. 91.2%, p = 1.000) and histological diagnostic accuracy (86.0 vs. 87.7%, p = 1.000) for malignancy. The procedure time was significantly shorter in the S- group than in the S+ group (32.4 +/- 11.7 vs. 39.7 +/- 8.6 min, p < 0.001).
CONCLUSIONS: EUS-guided tissue acquisition using a 25-gauge core biopsy needle without a stylet did not decrease the diagnostic yield for malignancy and was associated with a shorter procedure time than that associated with a stylet.