EUS-guided tissue sampling: comparison of dual sampling (Trucut biopsy plus FNA) with sequential sampling (Trucut biopsy and then FNA as required)

Background and study aims: Both endoscopic ultrasound- (EUS-) guided tissue sampling techniques, fine-needle aspiration (FNA) and Trucut biopsy, have advantages and limitations. The aim of this study was to develop a strategy of combining these two EUS-guided sampling techniques in order to maximize the diagnostic accuracy and minimize duplication. Patients and methods: In this multicenter study we performed dual sampling (i.e. with both FNA and Trucut biopsy) in 95 patients during phase 1 of the study and sequential sampling (i.e. performing FNA only when Trucut biopsy tissue cores were macroscopically inadequate) in 72 patients during phase 2. Results: During the study period, 167/401 patients referred for EUS-guided sampling were eligible for the study; only solid lesions were included. In 143/167 patients (86%), sampling was performed via the transesophageal or transgastric routes. When the dual sampling strategy was used, an accurate diagnosis was achieved in 78/95 patients by FNA, compared with 85/95 by Trucut biopsy (P= 0.21). The combined accuracy of the dual sampling strategy was higher than FNA alone (88/95 vs. 78/95, P= 0.048), but was not significantly higher than Trucut biopsy alone (88/95 vs. 85/95, P= 0.61). Using the sequential sampling strategy, an accurate diagnosis was achieved in 66/72 patients (92%) compared with 88/95 (93%) for dual sampling (P = 1.0), and 8/72 patients (11%) had to undergo FNA after Trucut biopsy failed to obtain an adequate sample. One patient with mediastinal tuberculosis developed a cold abscess following Trucut biopsy. Conclusion: A sequential sampling strategy, in which EUS-guided Trucut biopsy is attempted first, and FNA performed only when Trucut biopsy fails to obtain a macroscopically adequate sarriple, achieves a diagnostic accuracy of 92%, with 11% of patients requiring both sampling procedures.