Introduction: Endoscopic Ultrasound guided fine needle aspiration (EUS-FNA) has been widely used to collect samples from pancreatic cystic lesions (PCLs) for cytology and fluid analysis. However, EUS guided FNA has relatively lower sensitivity in discriminating the types of lesions as well as detection of malignancy. Recent studies have investigated the EUS guided through the needle biopsy (EUS-TTNB) as an alternative method for sample collections in PCLs. We conducted a systemic review and meta-analysis on the studies that compared EUS-FNA and EUS-TTNB for adequate sampling and diagnostic accuracy in patients with PCLs.
Methods: We performed a comprehensive search of the databases: PubMed/MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials from inception through May 10th, 2022. We considered randomized controlled trials, cohort studies, and case-control studies. We excluded abstracts, animal studies, case reports, reviews, editorials, and letters to editors. The primary outcome was sample adequacy which is defined as the presence of enough sample for histopathological evaluation. The secondary outcome was sample accuracy which is defined as the ability to have a definite diagnosis. The random-effects model was used to calculate the risk ratios (RR) and confidence intervals (CI). A p value < 0.05 was considered statistically significant. Heterogeneity was assessed using the Higgins I2 index.
Results: Nine observational studies involving 520 patients were included in the meta-analysis. The rate of sample adequacy was significantly higher in the EUS-TTNB group compared to the EUS-FNA group (RR 1.64, 95% CI 1.19-2.26, p =0.003, I2 = 95%) (Figure 1a). Only four studies compared the accuracy rate between the EUS-TTNB method and the EUS-FNA group. The diagnostic accuracy was significantly higher in the EUS-TTNB group compared to the EUS-FNA group (RR 2.03, 95% CI 1.13-3.65, p = 0.02, I2 = 87%) (Figure 1 b).
Discussion: Our meta-analysis demonstrated that the rates of both sample adequacy and accuracy were higher in the EUS-TTNB group compared to the EUS-FNA group. EUS-TTNB should be considered where applicable clinically for improving the diagnostic yield in patients undergoing evaluation of PCLs. Further randomized controlled trials are needed to confirm our findings.
