Comparison of endoscopic ultrasonography-guided fine-needle aspiration cytology results with and without the stylet in 3364 cases.

Background And Aim: Endoscopic ultrasound-guided fine-needle aspiration cytology (EUS-FNA) is traditionally carried out with the stylet, as it is believed to prevent blockage or contamination of the needle by tissue coming from the gastrointestinal wall. However, this recommendation has not been demonstrated on an empirical basis. The aim of the present study was to compare the yield of EUS-FNA in a very large series of patients with (S+) and without (S-) the stylet.

Methods: Until 2004, the stylet was used for EUS-FNA in our center. After that, the stylet was never used. The results of all EUS-FNA in solid lesions carried out by one endosonographer with the same needle type were compared before and after stylet use was stopped.

Results: 3364 EUS-FNA procedures (in 3078 patients) in solid lesions were included (1483 S+ and 1881 S-). There was no significant difference between the S+ and S- results for any variable other than the number of passes required. The number of passes was significantly lower in the S- group when sampling lymph nodes, wall lesions and when carrying out biopsies through the gastric or rectal wall. However the statistical differences disappeared after controlling for malignancy, location and lesion size.

Conclusion: This very large comparative study showed no benefit in diagnostic yield when using the stylet for EUS-FNA.