EUS-FNA WET-TECHNIQUE IN 31 SOLID PANCREATIC LESIONS: PISA EXPERIENCE

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 May 2016 and January 2017 at our Interventional Endoscopy Unit. The type and size (19 or 22 gauge) of FNA needle were chosen at the discretion of the endosonographers. Macroscopic on-site quality evaluation (MOSE) was performed and if a visible core was available, it was placed in formalin for histologic examination. Cellularity was assessed by using a 4-point scale (0=no cells to 3=highly cellular). Specimen adequacy was graded on a 2-point scale (0=not sufficient to make a diagnosis, 1=sufficient to make a diagnosis). The final diagnosis was based on pathological diagnosis of the surgically resected specimen for patients underwent surgical operation (8/31; 25.81%) while in the absence of surgical operation on a minimum follow up of 36 weeks (23/31; 74.19%): lesions spontaneously resolvedwithout signs of deterioration were consideredas benign; lesions showed enlargement, metastasis or with malignant symptoms were considered as malignant. Results: Patient median age was 63.03±11.98 years and the male/female ratio 15/16. Lesions were located in the pancreatic head in 17/31 (54.8%), pancreatic body/tail in 11/31 (35.5%) and uncinate process in 3/31 (9.7%). The mean size of lesions was 4.29 ±1.56 cm.The cytological diagnosis was pancreatic adenocarcinomain 24 (77.4%) cases, GI stromal tumor in 1 (3.2%) caseand was negative for malignancy in 6(19.4%) cases.22 G needles have been used in 10/32 procedures, 19 G in 22/32. Mean number of passes 3.4 ±0.1.Inthe 31/32 (97%)cases with adequate specimens, cellularity score (mean 2.29 ±0.78) was 1 in 6 (19.4%) cases, 2 in 10 (32.3%) cases and 3 in 15 (48.4%) cases.Only 2 cases resulted false negatives. No significant differences were found between the 19G and 22G needles in terms of number of passes (19G 3.30 ±0.82 vs 20G 3.41±0.73; p=ns), adequacy (19G 90% vs 22G 100%; p=ns) and cellularity of the sample (19G 2.0 ±0.71 vs 22G 2.41 ±0.80; p=ns), as well as in ability to obtain a correct diagnosis (19G 90.0% vs 22G 94.5%; p=ns). No adverse events occurred.Wet EUS-FNA technique hadsensitivity 92.59%, specificity 100%, positive predictive value 100%, negative predictive value 66.67% and diagnostic accuracy 93.55%. Conclusion: In our study wet EUS-FNA technique, performed with 19 and 22 gauge needles, showed a high performance in terms of adequacy and cellularity of the sample as well as in obtaining a correct diagnosis.Â