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BackTable / VI / Podcast / Transcript #23
Podcast Transcript: Adrenal Vein Sampling
with Dr. Mike Devane and Dr. Aaron Fritts
The procedure that everyone gets excited about! In this week's BackTable podcast Mike Devane talks us through adrenal vein sampling technique, including equipment/imaging tips and tricks, as well as pitfalls to avoid. Whether looking to build an AVS service, or just preparing for that once in a blue moon case, you're certain to take away a few pearls! You can read the full transcript below and listen to this episode here on BackTable.com.
Table of Contents
(1) When to Perform Adrenal Vein Sampling
(2) Set Up Routine for Adrenal Vein Sampling
(3) Adrenal Vein Sampling from a Jugular Approach
(4) Adrenal Vein Sampling Procedure
(5) Interpreting Adrenal Vein Sampling Results
(6) Pitfalls of Adrenal Vein Sampling
(7) Who Can Perform Adrenal Vein Sampling?
(8) Complications of Adrenal Vein Sampling Procedure
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[Aaron Fritts]
Hello everyone and welcome to the Back Table Podcast. Back Table is your resource to connect with your IR colleagues and learn tips, techniques and the ins and outs of the devices in your cabinets.
[Aaron Fritts]
This is Aaron Fritts, filling in as your host this week. I am pleased to welcome back Dr. Mike Devane to walk us through the adrenal vein sampling procedure.
[Aaron Fritts]
Welcome back Mike!
[Mike Devane]
Oh thank you. It's good to be here.
[Aaron Fritts]
So, for those listeners who didn't catch your prior renal ablation podcast, can you briefly tell us a little bit about yourself and where you're located?
[Mike Devane]
I'm in practice in Greenville, South Carolina. We have four IRs in our practice, currently. We do a broad scope of intervention, including interventional oncology and adrenal vein sampling just happens to be one of the procedures that we're apt to do from time to time.
[Mike Devane]
I've been in practice now for 14 years.
[Aaron Fritts]
We're pleased to have you here for this podcast. This podcast is meant to give our listeners a nice, overall blueprint of how to approach this procedure. Kind of what equipment is involved and any pitfalls they should avoid.
(1) When to Perform Adrenal Vein Sampling
[Aaron Fritts]
So before we get into the nitty-gritty of the procedure itself, can you tell us a bit about who is your typical referring doc for adrenal vein sampling, and what are they looking for in requesting this procedure?
[Mike Devane]
We have three referring type physicians. Primarily, we have an endocrine surgeon in town, and he has been sending us cases now for several years. He's very good. We have a handful of endocrinologists and recently, the reproductive endocrinologists have been asking us to do adrenal vein with ovarian vein sampling.
[Mike Devane]
From the endocrinologists and the endocrine surgeon, this is primarily Conn's Syndrome hyperaldosteronism, and those patients have hypertension and hypokalemia. They have an adrenal adenoma on CT, which not many people do, that's several, about 10 to 15%. Those are the typical patients that are sent from those referring physicians.
[Mike Devane]
The ones from the reproductive endocrinologists, what they're looking for is these patients have hirsutism, so they're looking for testosterone levels in both adrenal glands and the ovarian veins.
[Aaron Fritts]
Are you seeing much for Cushing's Syndrome or hypercortisolism?
[Mike Devane]
No. I think the last time I had a case of that was probably three or four years ago. And to be honest with you, if they sent me another one, I'd probably have to re-look at that protocol, 'cause I'm so used to doing one of two variations of adrenal vein sampling.
(2) Set Up Routine for Adrenal Vein Sampling
[Aaron Fritts]
When you have these patients come over, can you just walk us through your set up, what equipment you choose? I think you had said, previously, you have a variety of different catheters that you kind of choose from.
[Mike Devane]
Yeah. The first and foremost thing that I use is a pre-operative CT. I can't say enough how helpful that is, because looking for the right adrenal vein, which is always the more difficult one, oftentimes you can actually see the level where that adrenal vein is gonna come off its CT. So, if you know that it's gonna be around the T12 level, T12 pedicle, then you've got a good area to hone in on.
[Mike Devane]
I usually examine the pre-operative CT at length, and I get one on everybody. So, that's kind of been prior to them arriving. When they arrive, the first thing we do is--once we establish IV access--we start a cortrosyn drip for the ones that have Conn's Syndrome. We do .25 milligram in 500ml normal saline of cortrosyn and infuse that at 100ml per hour at least 30 minutes prior to procedure. And we want the patient lying down at least an hour prior to the procedure.
[Mike Devane]
There's some data that states that patients that have been standing up immediately prior to the procedure can alter the results.
[Mike Devane]
Then, on my table, usually I have a magnifying work lamp, just kind of like one you would buy at Lowe's, so that way I can punch holes in the catheters. I take an array of catheters and use a Cook hole-punch kit. Unfortunately, that kit has been discontinued and through the years, several pieces of the kit have disappeared. I'm assuming they got thrown away when the sharps were disposed of. So, I've kind of had to revert to using an 18 gauge needle as my primary hole-punch, but I still use the Cook kit. It has little metal stylets to help you create the hole. I use an 18 gauge needle and I use the little metal tin that the Cook hole punch kit comes in. I use that as the backing for punching the hole into the catheter. And I usually punch a hole around two to three millimeters from the tip, along the superior aspect of the catheter.
[Mike Devane]
The catheters that I gravitate towards are a C2--all of these are five French catheters--a five French C2, an RDC, a Simmons 1, a Simmons 2, a Mickelson. I've started using, probably in the last year or two, the Cook CHB. I found that sometimes that can be helpful if you can't get in with the other catheters.
[Mike Devane]
Prior to starting the procedure, I like to have all my holes punched in the catheters and have all that ready so that way, any of the needles that I'm using aren't contaminated with blood. If you're punching a hole in the catheter, you certainly don't wanna stick yourself. That decreases your risks. So all those catheters are ready by the time we put the patient on the table and ready to sedate.
[Aaron Fritts]
Okay, great. Just real quick, going back to that preoperative CT, do you do a CT venogram protocol, or is it just a regular protocol?
[Mike Devane]
Most of our patients are getting the wash-out protocol, so that's gonna include the pre and the post. So, generally it's in a delayed venous phase that's out to 60 seconds, 90 seconds. I can't remember, but it’s around there.
[Aaron Fritts]
In terms of access, are you doing unilateral access or bilateral access?
[Mike Devane]
I do unilateral access. I don't do the simultaneous sampling. I did that when I first came on into practice and that's kinda how I learned how to do it. That is so much more difficult.
[Mike Devane]
So I think if you used cortrosyn stimulation, you can avoid having to do the simultaneous. You can go directly to starting your samples.
[Mike Devane]
So that's how I do it for Conn's Syndrome and it's worked pretty well over the years. And certainly it's technically a lot easier. I've found that when you're doing the simultaneous access, it's so hard to keep the catheter in place in the right and the left at the same time. And you're tryin to get the catheter back in the right and the catheter over the left flips out, it just becomes so difficult, I just don't like doing it that way. So I do simultaneous access.
[Mike Devane]
Now, if I'm doing gonadal vein sampling, I typically will do jugular access for the gonadal veins and I'll also prep off the groins for the adrenals, so I'll prep off the right femoral for the adrenal.
(3) Adrenal Vein Sampling from a Jugular Approach
[Aaron Fritts]
Okay, yeah, that was my next question is have you ever done an adrenal vein sampling from a jugular approach, for anybody who may have chronic clot... you know DVT or something like that. If you've ever had to do that?
[Mike Devane]
You know, I've considered doing it, since I'm already doing the jugular access first because I do the ovarian veins first. To be honest with you, it's so easy to get into the left through the groin that I just haven't tried it that way. And I can't imagine what catheters you would use for the right because the right can be very tough.
[Aaron Fritts]
Right, right.
[Mike Devane]
Once you've kind of gotten your protocol down for getting to the right adrenal vein from the femoral, I'm always afraid to switch and mess that up.
[Aaron Fritts]
Basically, confirming that you're in place, do you do a slight little, gentle, injection? Or do you just-
[Mike Devane]
Very, very gentle puff of contrast, and I don't do any type of DSA run. I just do fluoro image save. And just a gentle puff of contrast, 'cause one of the risks of this is, if you infarct the adrenal gland, you can certainly cause some issues. You're gonna cause adrenal hemorrhage and then it hurts the patient also. They'll actually feel it on the table and that vein can go into spasm. Then it's hard to sample blood from it. So, I use a very, very gentle puff of contrast. Then when I'm doing my aspiration, I make sure that the first few drops of blood contain that contrast. I get rid of that, so there's no dilutional effect. So I usually waste the first half an ml of blood before I've made my sample.
(4) Adrenal Vein Sampling Procedure
[Aaron Fritts]
Walk us through the sampling part of it.
[Mike Devane]
So, my first sample is, I go ahead and I get the one from the femoral and label that as peripheral and hand that to the nursing staff so they can get it processed. I usually go to the right adrenal vein. The preoperative CT tells me exactly where to go, and I usually start off with the C2. And I try to get a sample with the C2. If I can't get a sample with the C2, I try to get a sample with the RDC.
[Mike Devane]
Typically, I can get a sample with one of those two catheters. Typically I feel fairly comfortable.
[Mike Devane]
Once I feel that I'm fairly comfortable that I've gotten the right adrenal sampling, I usually go over the bifurcation with that catheter. I switch out for a Simmons 2 and get my left side, and the left side is usually pretty easy with a Sim 2. I think I've had a couple, three cases through the years I've actually had to switch out for a Simmons 3 to get into the left because of the angle. But generally speaking, the Simmons 2 will get you where you need to go.
[Mike Devane]
So then, once I've sampled peripheral, right and then left, I go back to my right to make sure that I absolutely am confident that I have a sample. I will try with the Simmons 1, the Mickelson and then the CHB catheter, just to make sure that I've absolutely got into the right. I send several samples of the right, because sometimes if you don't see that inferior emissary vein, and only the parenchymal stain of the adrenal, were you absolutely in the adrenal vein or were you in the little branch of the hepatic?
[Mike Devane]
So, typically, I send several samples. Unfortunately, we don't have the Rapid Assay, where I practice, so I'm not blessed with being able to know whether you got an adequate sample. Usually I don't know until later that afternoon when the cortisol levels start to come back.
(5) Interpreting Adrenal Vein Sampling Results
[Aaron Fritts]
That was my next question--if you wait with the patient on the table for the results to come back. It sounds like you just get as many samples as you can and then hope you got what you needed, right?
[Mike Devane]
Yeah, that's how I do it. I've noticed from the lab that once we send the blood to the lab and they get a cortisol level, usually the peripherals come back fairly quickly, because those are low levels. And the right and left adrenal veins, they have to do several dilutions, so that usually takes them four to five hours of dilution in our lab to get a result back. It’s far too long for the patient to be on the table, so we just do all the samples and send them off and hope that we got the result.
[Mike Devane]
I wish we had the Rapid Assay. That would be really nice.
[Aaron Fritts]
Are you interpreting the results and including them in your dictation?
[Mike Devane]
No, typically not. Typically, what I do is, because the cortisol levels I'll get back later that afternoon or later that evening--sometimes into the night once they finish the dilutions. The aldosterone levels don't come back until the next week. Those are a send-out lab for us. So, usually that takes a week, so I dictate something into our electronic medical record.
[Mike Devane]
We have Epic, and I'll dictate a follow-up note saying, "These were what I saw". Then I also look at the endocrinologist's note to see if they agree with how I interpreted the samples, as well.
[Aaron Fritts]
Gotcha. Do you usually do a follow-up phone call with them? Or only if there's an issue?
[Mike Devane]
Generally only if there's an issue. We have a pretty good working relationship and most of the adrenal veins that are positive, or they localize to a side, they're gonna go to the endocrine surgeon. And, usually we discuss those cases or he sends me an electronic medical flag saying, "Yeah, that left adrenal was positive for an adenoma and I'm gonna take them to adrenalectomy." So, we have some follow-up from that.
[Mike Devane]
That was one of the things that our adrenal surgeon said from the very beginning. When I first started doing them in this practice, he said, "Look, I'm gonna be sending you patients and I'll give you feedback, and that way you can use that feedback to make sure that you're getting good samples and that we're happy with the results." So, that's been very nice.
(6) Pitfalls of Adrenal Vein Sampling
[Aaron Fritts]
I just thought of one pitfall that I came across in working with these smaller little community hospitals. You might get a request for an adrenal vein sampling, but it's really important to check with your lab to make sure they have the resources to process it and do collection. If you catch them off guard, it could be a total waste and you obviously don't wanna waste the patient's time and put them through an unnecessary procedure.
[Aaron Fritts]
Any other pitfalls that you can think of?
[Mike Devane]
Well, early on, when it was probably our first or second case that we did here, we actually had a lab mishap where we had to bring the patient back and re-sample. I forget exactly what happened in the lab, but they weren't quite prepared.
[Mike Devane]
So, you made a very good point about making sure that the lab is prepared. Our lab here is wonderful. It's run by the pathologist who I sat down with after this incident. We went through the procedure and how quickly they need their blood samples from the time we obtain them, and how they were gonna receive them, and how they want them labeled. And that's really crucial because for the last eight or ten years that we've been doing it, we've had really good success from the lab. They've done a fantastic job. That is one of pitfalls, you definitely wanna make sure your lab is prepared to receive those samples.
(7) Who Can Perform Adrenal Vein Sampling?
[Mike Devane]
I think that this is a procedure that anybody can do in their lab. This is what I like about it. You don't have to have a fancy laser, you don't have to have fancy equipment or anything to do this. This is something that anybody going out into private practice, or any academic practice, for that matter, can do. It's not a sexy procedure. It's not exciting, but I think it's important. And it's important to the patients--these are patients that you potentially cure of very severe hypertension.
[Mike Devane]
It's a tedious procedure. It's not what I would call a fun procedure. It's not like doing an embolization, filter-retrieval, or foreign body retrieval. It's not sexy and fun. But I think it's one of those procedures that anybody in practice can do. You can get good at it and provide this service to the community. I think it's very helpful.
[Mike Devane]
Our endocrine surgeon had been here for a while before I got here, and none of my partners previously had done adrenal vein sampling. He was used to sending his patients out. He approached me one time when we first started doing this and said, "Do you do adrenal vein sampling? 'Cause I just sent a patient to the Mayo Clinic in Rochester to get their adrenal vein sample." And I said, "Yeah, I did some in fellowship. I think that's a service we can provide here."
[Mike Devane]
It's been satisfying to know that those patients don't have to go traveling. They can stay in our community and they can go to our hospital locally and not have to get the procedure done elsewhere.
[Aaron Fritts]
It’s great to just be able to provide that service to referring docs.
[Aaron Fritts]
As you mentioned, it's not a terribly sexy procedure, but very important to be able to provide that.
(8) Complications of Adrenal Vein Sampling Procedure
[Aaron Fritts]
Assuming everything goes smoothly, how long does this procedure take for you?
[Mike Devane]
Usually, it's around an hour of procedure time for me. I usually observe the patients a couple hours after the procedure to make sure that with the cortrosyn and everything, that their blood pressure is not too terribly out of control and that they're feeling okay. I usually watch them for a couple hours and then let them go home. I tell the patients they're usually gonna be here about an hour for prep, an hour for the procedure, and two hours for post. So, around four hours for the procedure overall.
[Aaron Fritts]
And any other complications to look out for, after the procedure?
[Mike Devane]
I haven't really noticed too many complications. It's a venous puncture and, generally, that's pretty safe. I have noticed that their hypertension sometimes gets a little bit out of control from the cortrosyn. So, as soon as I'm done sampling, I'll go ahead and turn off the cortrosyn drip.
[Mike Devane]
I haven't really seen too terribly many complications from it. Occasionally, you'll get that patient that has a little bit of flank pain. For that moment when you're sampling blood from the adrenal vein, they can kind of feel that. But, other than that, that's usually very short-lived. I haven't really had anybody complain of pain after the procedure.
[Aaron Fritts]
From the aspiration?
[Mike Devane]
Yeah, from the aspiration. I think as soon as that catheter goes in and you start aspirating blood, they can kind of feel the pressure on the adrenal vein.
[Aaron Fritts]
Right, right.
[Mike Devane]
And sometimes that's a good indication that you're in the right place, as opposed to in the right hepatic vein. That's the crux of the matter: getting into the right adrenal vein and differentiating that from the small branches of the hepatic vein from the liver. It just takes time to learn that pattern. Look for the emissary vein, if they have one. Sometimes they don't, and sometimes, all you see is the little parenchymal stain. Unfortunately, that delta stain in the herringbone pattern of the liver and the right adrenal vein can look very similar if you don't have an emissary vein. Because they can look very similar, I mag up on fluoro when I give a puff of contrast just to make sure I'm not seeing anything drain, eventually, back into a hepatic vein.
Podcast Contributors
Dr. Mike Devane
Dr. Mike Devane is a practicing interventional radiologist at Greenville Health in Greenville, SC
Dr. Aaron Fritts
Dr. Aaron Fritts is a Co-Founder of BackTable and a practicing interventional radiologist in Dallas, Texas.
Cite This Podcast
BackTable, LLC (Producer). (2018, February 18). Ep. 23 – Adrenal Vein Sampling [Audio podcast]. Retrieved from https://www.backtable.com
Disclaimer: The Materials available on BackTable.com are for informational and educational purposes only and are not a substitute for the professional judgment of a healthcare professional in diagnosing and treating patients. The opinions expressed by participants of the BackTable Podcast belong solely to the participants, and do not necessarily reflect the views of BackTable.
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