ACCURACY OF VISUAL ON-SITE EVALUATION (VOSE) IN PREDICTING THE ADEQUACY OF EUS-GUIDED FINE NEEDLE BIOPSY: A SINGLE CENTER PROSPECTIVE STUDY

Aims EUS-FNA is the standard procedure for the diagnosis of pancreatic lesions with accuracy rate of 78-95%. Rapid onset evaluation (ROSE) decreases the number of passes but is not always available. New needles have been developed to obtain tissue acquisition (fine-needle biopsy, FNB) with a relatively better diagnostic adequacy with fewer passes. Without ROSE, there is no clear criterion for determining the number of FNA passes and therefore unnecessary passes are performed. We introduced an easy and rapid method of direct classification of EUS-FNB sample namely Visual on-site evaluation (VOSE).

To assess the accuracy of VOSE in predicting the histo-cytological adequacy of specimens to reduce unnecessary passes. To evaluate the diagnostic power of FNB and the rate of core tissue obtained.

Methods Prospective single center study on patients with pancreatic lesions that underwent EUS-FNB. VOSE parameters were: presence of blood, macroscopic visible core (MVC), number and length of specimen. The association between VOSE tool and cyto/hystological adequacy was assessed. Fisher’s exact test and Student’s t-test used to compare categorical and continuous variables. P < 0.05 considered statistically significant.

Results From January 2017 to February 2019, 99 patients (58.6% male; mean age 68.4 ± 10) were enrolled, including a total of 102 lesions. Total number of passes was 358. The 92.7% of samples were adequate and the rate was higher with the 22-G needle than with 25 G (96.5% vs 89.2% p 0.01). VOSE “presence of MVC plus multiple specimens plus long specimen” predicted histo-cytological adequacy with 49.7% of sensitivity, 58.3% of specificity and 94.5% of positive predictive value, saving about 50% of passes.

Conclusions FNB provides a high rate of adequate specimen especially with the 22 G needle. The VOSE tool ‘presence of MVC plus multiple specimens plus long specimen’ can be used as predictor of histo-cytological adequacy, with acceptable accuracy and a minor number of passes.