Comparison of "Wet Suction" Technique to Contemporary "Dry Suction" Technique Using a 22 Gauge Needle for EUS FNA

ROLE OF SUCTION IN EUS-FNA: Current suction technique involves suctioning the aspirate into the needle that has an air column. The needle is not flushed with any liquid prior to passing into the desired solid lesion. Suction is applied when the needle is within the lesion leading to aspiration of tissue into the needle. This is the standard technique and some have done with and without the stylet. There are some data that favor non use of a stylet. WET SCTION TECHNIQUE: Wet suction technique involves flushing the needle with 1-2 cc of saline to replace the column of air with saline. The needle is now passed into the desired lesion. Suction is applied at maximal strength and needle moved back and forth within the lesion to obtain as aspirate. Drops of saline can be seen moving into the suction syringe as the aspirate moves into the needle. Needle is now withdrawn and aspirate delivered on to a slide by using a stylet and or flushing air into the needle with a syringe. HYPOTHESIS The effect of suction for the purpose of aspirating cells and / or tissue during fine needle biopsy may be significantly improved by filling the column of the needle with a less compressible fluid. The volume of vacuum being pulled may be negatively impacted by the expansion of air within the needle. Replacing the air with sterile saline may thus improve the suction transferred to the needle tip by ensuring that the full volume of the vacuum syringe is transferred to the distal tip of the needle. This effect would be most pronounced in larger gauge needles which would have a larger internal volume. An additional benefit of filling the needle with saline prior to aspiration is the speed of the pressure transfer. The theory is that the air in the needle may absorb some of the force of the sudden application of vacuum. A column of saline in the needle may increase the velocity of the pressure transfer providing more tissue and less blood.

Sex

All

Minimum age

18 Years

Inclusion Criteria:

* Solid mass lesions under going endoscopic ultrasound (EUS)

Exclusion Criteria:

* Coagulopathy
* Age below 18 years
* Cystic or solid-cystic lesions.