AB085. P057. Early monocentric experience in EUS-FNA wet-technique for pancreatic lesions

Background: A preoperative diagnosis of pancreatic adenocarcinoma is often indispensable to guide the right treatment. EUS-FNA is an established procedure for obtaining a pathological specimen and a correct diagnosis. The FNA wet suction technique relies on pre-flushing the needle with saline instead of the air column contemplated in the dry technique. The aim of this study was to evaluate the performance of wet EUS-FNA technique with 19 and 22 G needles.

Methods: Thirty-one consecutive patients underwent EUS-FNA for pancreatic lesions between 7/2016 and 1/2017 at our interventional endoscopy unit. The type and size (19 or 22 G) of needle were chosen at the discretion of the endosonographers. Macroscopic on- site quality evaluation (MOSE) was performed. Cellularity was assessed by using a 4-point scale (0: no cells to 3: high cellularity). Specimen adequacy was graded on a 2-point scale (0: unable to make a diagnosis; 1: adequate tissue). For patients who underwent surgery (8/31) the final diagnosis was based on the resected specimen. In the absence of surgical pathology the final diagnosis was based on a minimum follow up of 36 weeks (23/31).

Results: Patients median age was 63±11 years (15 males and 16 females). Lesions were located in: pancreatic head 17/31, body/tail 11/31, uncinate 3/31. The mean size of lesions was 4.3±1.6 cm. Results of FNA: adenocarcinoma 24 (77.4%), 1 GI stromal tumor, 6 negative for malignancy. In one case the procedure was repeated (successfully) for inadequate specimen. 22 G needles have been used in 10/32 procedures, 19 G in 22/32. Mean number of passes 3.4±0.1. Cellularity score (mean 2.29±0.78) results: score 1 in 19.4%, score 2 in 32.3%, score 3 in 48.4% cases. In 2 cases there was no accordance between FNA and the final diagnosis. Regarding the use of the two needles (19G and 22G), no significant differences were found in terms of number of passes (19G 3.3±0.1 vs. 20G 3.4±0.1; P=ns), adequacy (19G 90% vs. 22G 100%; P=ns) and cellularity of the sample (2.0±0.1 vs. 2.41±0.8; P=ns), as well as in ability to obtain a correct diagnosis (19G 90.0% vs. 22G 94.5%; ns). No adverse events occurred. Wet-FNA sensitivity and specificity were respectively 92.59% and 100%, positive and negative predictive values were respectively 100%, and 66.67% (accuracy 93.5%).

Conclusions: Wet EUS-FNA technique, performed with 19G and 22G needles, showed a high performance in terms of adequacy and cellularity of the sample as well as in obtaining a correct diagnosis.