Meta-Analysis for Cyto-Pathological Outcomes in Endoscopic Ultrasonography-Guided Fine-Needle Aspiration With and Without the Stylet.

Background: Theoretically, use of the stylet during endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) will prevent the tip of the needle from being blocked and the sample from being contaminated, improving the quality and diagnostic yield of specimens.

Aim: This meta-analysis aimed to evaluate any benefit from the use of a stylet during EUS-FNA.

Methods: MEDLINE, EMBASE, WEB of SCIENCE, and the Cochrane Central Register of Controlled Trials were searched for articles published through October 2015. A fixed-effects model was used to calculate the pooled effects when there is no heterogeneity and a random-effects model was used in situations with significant heterogeneity.

Results: Five prospective randomized controlled studies and two retrospective studies of a total of 5491 specimens (2504 specimens in the S+ group and 2987 specimens in the S- group) were included in this study. The pooled analysis demonstrated no significant differences in the adequate sample rate between the S+ group (2135/2504, 85.26 %) and S- group (2609/2987, 87.35 %) [odds ratio 0.94 (95 % confidence interval 0.79-1.11), p = 0.45]. Furthermore, the rate of cellularity > 50 %, the contamination rate, and the blood contamination rate were not significantly superior in the S+ group when compared with the S- group.

Conclusions: Whether the use of a stylet improves the proportion of adequate specimens or quality of the specimen is questionable. Our results suggest that the use of a stylet dose not guarantee any advantage during EUS-guided tissue sampling.