A meta-analysis comparing ProCore and standard fine-needle aspiration needles for endoscopic ultrasound-guided tissue acquisition

Background and study aims: To overcome the limitations associated with cytology, a uniquely designed needle (ProCore) was introduced in an effort to obtain a core of tissue under endoscopic ultrasound (EUS) guidance. However, studies comparing the sample quality between ProCore and standard-design fine-needle aspiration (FNA) needles have yielded varying results. A systematic review and meta-analysis was therefore conducted to compare the performance of the ProCore and standard FNA needles when performing EUS-guided tissue acquisition. Patients and methods: MEDLINE and EMBASE were searched to identify all published manuscripts that compared the ProCore needle with standard FNA needles. Noncomparative and technical feasibility studies were excluded. The main outcome measures were diagnostic adequacy, diagnostic accuracy, acquisition of histological core tissue, and mean number of passes required to achieve a diagnosis when sampling solid lesions. Results: Nine studies (total 576 patients) met the inclusion criteria. There was no significant difference in diagnostic adequacy (75.2% vs. 89.0 %, odds ratio [OR] 0.39, P= 0.23), diagnostic accuracy (85.8% vs. 86.2 %, OR 0.88, P= 0.53) or rate of histological core specimen acquisition (77.7% vs. 76.5 %, OR 0.94, P= 0.85) between the ProCore and standard FNA needles, respectively. The mean number of passes required for diagnosis, however, was significantly lower when using the ProCore needle (standardized mean difference -1.2, P< 0.001). Conclusions: Current data do not demonstrate a significant difference between the ProCore and standard FNA needles for sample adequacy, diagnostic accuracy or acquisition of a core specimen. However, the ProCore needle establishes the diagnosis with fewer passes.