Sonopath Forum

Prostate FNA technique

Hello, I am attempting an ultrasound-guided FNA of a prostatic mass this week. I attached a photo of what I believe the approach/angle should be. The pen would be the syringe…I am at home right now.

Any tips you all have for me would be great. Angles, aspirating technique, needle size, etc. I always think of worst-case scenerios…so I figure I should avoid hitting the colon, and I guess going too distal and lacerating the uretha would not be good either, or too cranial and hitting a ureter. Do my angles look correct in the attached photo? Is this best with two people?…one to hold the probe and the other to perform the FNA?

Thanks for your help.

Robb

Comments

KV CVT SonoPath

August 1, 2019 at 1:32 am -

With the patient laying in

With the patient laying in right lateral recumbency we usually hold the probe in our left hand with the marker facing the head and approach the prostate from behind the probe. Make sure when you line up with the area of the prostate you are aiming for, your probe and needle are in a “V” formation. V for victory. 🙂

Catlady59

August 1, 2019 at 2:20 am -

Yes I agree with KV- right

Yes I agree with KV- right lateral recumbancy. Left hand on the probe, right hand on the syringe. Push with the probe just enough so that there is nothing between your probe and your target. Just like in the video on our site, line up the syringe in alignment with the probe- so it helps to have the animal close and observe your angle from above. Go in slowly so you can see the urethra and avoid going through it. We usually use 25g needles. 3 passes at very slightly different trajectories to get fresh tissue each time.

FYI- FNA a spleen when you can – it is one of the easiest to start with as it is a big target. remember to put on power Doppler so you can see any vasculature you need to avoid.

I definitely recommend making a phantom jello mold and practicing so you can see the effect of the different angles of the syringe in relation to the probe. You will see what a big difference it makes in visualizing the needle if you are not aligned perfectly with the probe. Recipe is on our website

https://sonopath.com/resources/ultrasound-resources/phantom-mold-recipe-fna-practice

Catlady59

August 1, 2019 at 2:22 am -

and don’t forget complete

and don’t forget complete sedation with propofol, ket/val or similar. We recommmend avoiding dexdomitor as this dilates blood vessels and we don’t need those in our way any more than can be helped!

August 3, 2019 at 5:41 pm -

Gang dont we have a prostatic

Gang dont we have a prostatic fna video somewhere? Maybe on you tube? If not let me know Ill make one later this month.

Rob I go from the same angle you work form in positions 3 and 4 SDEP but since im right handed I move the probe to the left hand. Splay the right leg up by a technician and angle medially away from the coxofemoral joint. But bascially do a position 3 and push more with the scanning hand to put the prostate right up to the body wall and should get to a 1 cm or less depth.

4ebersoles

August 4, 2019 at 1:20 pm -

Thanks EL for the

Thanks EL for the description!

When doing a FNA…. do you want the needle to enter the “target organ” at a slight angle, or perpendicular? Hold the probe perpendicular and angle the needle?

Karen

robbmurphie

August 4, 2019 at 3:27 pm -

Thanks for the info/help

Thanks for the info/help everyone. I performed the FNA the other day. The procedure went very well. The mold really helps with perfecting technique.

I initially tried to attempt placing the probe more perpendicular to the dog…but I found that I needed to angle the probe facing up/angled dorsally some (kind of like the angle you are not supposed to take when looking at the aorta region)

I centered the probe over the prostate mass, pressed fairly firm to where the probe was essentially right over it, and then aspirated. I made sure to angle the syringe at a touch of a V to the probe. We decided to take two samples…one via woodpecker/several passes at different angles…technique, and the other to aspirate some fluid within the cavitated prostate mass…aspirated about 1 ml of fluid. For the aspiration part, I found it easier to have another person pull the fluid with the syringe. I decided to go with a 1 and ½ inch, 22 gauge needle. I just felt 25 might be a little too small….and an 18 or 20 might be a little too traumatic for this region.

Also…I don’t have the report in front of me, but the cytology came back concerning for carcinoma, noted atypia, necrosis…etc. Within 24 hours of starting Rimadyl, he is just about back to normal. It goes to show how nsaids help not only the inflammatory discomfort…but also have the cox-2 anti-neoplastic benefits. Poor prognosis, but at least he his feeling better and should have a good quality of life for a little while longer.

4ebersoles

August 4, 2019 at 5:41 pm -

Thanks for the description.

Thanks for the description. Kudos for getting the diagnosis! 🙂

August 11, 2019 at 10:48 am -

Karen V for victory regarding

Karen V for victory regarding the needle angle and the probe but regarding the target angle there are no rules just get the target as close tot he probe as possible with a short inccocuous window and sometimes this takes creativity.

4ebersoles

August 11, 2019 at 10:34 pm -

Thanks Eric! Good to know

Thanks Eric! Good to know target angle is not so much the issue as probe to needle V, and good patient positioning to get it lined up.

KV CVT SonoPath

August 11, 2019 at 10:55 pm -

Link to the ADAIN procedure:

Link to the ADAIN procedure: https://sonopath.com/resources/ultrasound-guided-procedures/adain-procedure

Also more prostatic sampling here: Series 4: The Birds & The Bees of Veterinary Reproductive Clinical Sonography