decided not to proceed with study at this time

The purpose of the study is to compare two particular techniques of tissue (capillary vs wet-suction techniques) sampling during endoscopic ultrasound guided fine needle aspiration/biopsy (EUS-FNA/FNB) of a solid lesion to determine the diagnostic yield and procedure logistics (e.g. procedure time).

All adult patients who are undergoing EUS for solid lesions at Loma Linda University Health gastroenterology lab. These patients will be recruited at the time preceding their endoscopy in the Gastroenterology lab. They will be explained the goals, randomization, and interventions of the study. The collected patient information, as well as the steps to safeguard the information, will be explained.

Patients will be randomly assigned to capillary or wet-suction techniques arms according to computerized randomization program that has already been generated.

All patients will undergo routine EUS under possible moderate sedation or general anesthesia, with FNA/FNB. Cook Pro-core 22 gauge needle will be used for all the procedures. For each lesion undergoing FNA/FNB procedure, a total of 4 passes will be made using the selected technique.

The research aspect differentiates the method of tissue acquisition: modified wet-suction technique versus the "slow pull" capillary technique.

For the modified wet-suction technique:

1. The stylet will be removed at the onset of procedure. It will not be used unless it is necessary to de-clog the needle. Each de-clogging, if necessary, will be noted.
2. 10 mL suction syringe filled with saline will be used first to prime the needle until there is about 5 mL of saline left within the syringe
3. Then the plunger will be withdrawn against the locked three-way stopcock to establish vacuum. After this initial step, syringe with saline will not be removed for the entirety of the procedure unless technical issues arise, e.g. de-clogging.
4. Once the needle is introduced into the lesion of interest, the suction will be re-established by opening the three-way stopcock.
5. 10-20 to-and-fro needle motions will be done, emphasizing the edges of the lesion with fanning.
6. At the termination of each pass, the three-way stopcock will be closed prior to withdrawal of the needle from the lesion, to prevent suction of the specimen into the syringe itself.
7. Prior to steps to collect the specimen, the vacuum will be released, and after which the three-way stopcock will be turned to the open position.
8. Then the syringe plunger will then be pushed to collect the first drop of the specimen onto the glass slide for smear (thus making two glass smears for each pass, which will then be preserved into alcohol), and then the rest will be expunged onto the formalin for cell block.
9. Then the vacuum will be re-established as noted in step 3, ready for further needle passes.
10. For the first three passes, collection for both smear and the cell block will be done. For the last pass, all specimens will be collected on to the same cell block. Thus 6 total slides (which will be numbered or lettered consecutively for identification), and 1 formalin jar for cell block will be made for each patient/lesion.
11. Again, unless technical issues arise, the syringe will not be removed once initial priming is done and vacuum is established. Any technical issues will be noted within the procedure report.

For the capillary "slow pull" technique:

1. With the stylet slightly pulled back, the needle will be introduced into the lesion of interest, at which time the stylet will be pushed in to expunge any contaminating material.
2. The stylet will be slowly withdrawn by an assistant until completely removed.
3. 10-20 to-and-fro needle motions will be done, emphasizing the edges of the lesion with fanning.
4. After removal of the needle from the lesion, the stylet will be re-inserted. The first drop of will be collected for tissue smear, while the rest will be expunged first by stylet, saline, then air into formalin jar for cell block.
5. Stylet will then be re-introduced, ready for further passes.
6. For the first three passes, collection for both smear and the cell block will be done. For the last pass, all specimens will be collected on to the same cell block. Thus 6 total slides (which will be numbered or lettered consecutively for identification), and 1 formalin jar for cell block will be made for each patient/lesion.

Specimen handling:

Tissue smears will undergo for Papanicolaou staining, and the tissues preserved in 10% formalin solution will be processed for cell block.

The subjects will follow up with the Gastroenterology Clinic and/or their referring doctor. Patient may be called or receive a letter regarding their pathology results and for further follow-up as needed, per routine

Inclusion Criteria:

• All adult patients (greater than 18 years of age) who are referred for EUS guided sampling of solid lesions.

Exclusion Criteria:

• Any patients with contraindication to EUS- fine-needle aspiration/fine-needle biopsy (FNA/B), including those on anti-platelet or on anti-coagulation therapy, or with congenital disorders.
• Patients with cystic lesions or submucosal lesions will also be excluded.