Comparison of Three Different Tissue Acquisition Techniques During Endoscopic Ultrasound-guide Fine Needle Biopsies of Solid Tumors: A Randomized Single Blind Clinical Trial.

Endoscopic ultrasound guided fine-needle aspiration (EUS-FNA) has been used since 1990's for the diagnosis and staging of esophageal, gastric, duodenal, pancreatobiliary, rectal mediastinal lesions and intra-abdominal lymphadenopathy. Studies have shown a variable range of specimen adequacy when performing pancreatic biopsies with the standard fine needle aspiration (FNA) needles with this modality. There are several factors that affect the overall diagnostic yield of this procedure, such as endosonographer experience, presence of cytopathologist during the procedure, the needle diameter and the number of passes. In this study we will compare the yield of recently available fine biopsy needles (FNB) using three different techniques to obtain samples from solid lesions. The three techniques to be compared in this study are: stylet slow pull (SP) vs dry suction (DS) vs wet suction (WS).

wall cells.

In the "suction technique" the stylet of the needle can be left in place or removed before puncturing the lesion. Once the needle is inside the target, negative pressure is applied through a 10 or 20 cc syringe connected to the needle.

The wet suction technique consists of flushing of the needle with 5 ml of saline solution to replace the column of air within the lumen of needle with saline solution before needle aspiration. Once the needle is flushed, negative pressure is applied with a 10 or 20 cc syringe connected to the needle.

In the slow pull technique, the stylet is left in place in the needle and is slightly retracted prior to puncturing the lesion. Once the needle is inside the target, the stylet is pushed completely into the needle to remove any contaminant cells and several back and forth movements are done while slowly withdrawing the stylet.