Cryoablation of the Stellate Ganglion: Procedure Technique & Patient Outcomes

[Dr. Jacob Fleming]
I would like to jump in and talk some specifics about the stellate ganglion. First of all, what the hell is the stellate ganglion?

[Dr. Alexa Levey]
I love it. The way I describe it to my patients in Houston, and you think about it in any big city you are, think of it as it's the 610 loop in Houston, it's the big loop that goes around the city. It sits on either side of your neck and it receives inputs coming in from the brain, go into it, get regulated, go out to the extremities, go down your chest, go down to your heart, go to the tops of the lungs, and then vice versa. Things come back in there and get regulated. It's a major regulatory center of inputs from the brain and from the extremities and vice versa.

It has been implicated as far back as the 1940s in playing a role in heart regulation. What they found is that people who have rapid heart rates, if they did a sympathectomy of the left stellate ganglion, refractory ventricular tachycardia, some patients would get some improvement in those symptoms. Over time, they started blocking the stellate ganglion. They would block the left and then if that didn't work, they would try blocking the right. Never at the same time because the thought is that you could potentially completely stop the heart. With that being said, I can tell you I have now cryo-ablated both sides, granted that patient, now ears wide open, had a pacemaker and was a hundred percent pacemaker-dependent. I wouldn't just jump in and do that.

That's where it first started off in the literature was refractory ventricular tachycardia. Then what they found out, and I forget why this was initially done, is they did a lot of retrospective studies on combat veterans and they found that combat veterans, when they blocked the right stellate ganglion, they had better outcomes with management of their PTSD and anxiety when in combination with therapy than without the stellate ganglion block for up to or over three months. Usually three months was when they start seeing a lack of benefit and they'd usually have to go back in for another block again. That was using only lidocaine. Very interesting, not always using a steroid versus if you look at retractory, whenever you have VTAC, if you do lidocaine, as soon as that's off, they're going right back into VTAC. If you do a steroid, once that wears off, they're going right back into VTAC. There's also some interesting nuance, I would say, too, to VTAC to which patients respond and which don't, but I think I'll avoid diving deep into that right now. You can do an assessment and determine who's going to respond. Just interesting to know, PTSD, lidocaine kind of works, VTAC, good. Complex regional pain syndrome, so regulatory of nociceptive symptoms, particularly for the upper extremity and for the face, is the target of the stellate ganglion. Again, once the block wears off, symptoms come back.

Then we get into long COVID. There was a paper published that looked at two case reports on patients where they blocked the stellate. Why would they block the stellate for long COVID? That makes no sense. Long COVID is not just a, "I'm a little sick," cough that people seem to think it is. It is this terrible syndrome where patients have a predominant of dysautonomia symptoms where their heart rates can be anywhere, resting, 120 to 130, they stand up, it's 140s, where they have these terrible vertigo episodes daily that they feel like they're going to pass out multiple times a day. I had a patient who got a subarachnoid hemorrhage as a result of this dysautonomia, where they develop POTS syndrome and their blood pressure drops into the toilet, but then goes super high and patients have underlying hypertension. They're on all these weird antihypertensives and then their blood pressure drops, they get dizzy and they faint, where they have terrible brain fog, where they try to sit there and think about what words they want. It's almost like they've had a stroke. The words are in their head, but they can't communicate them out, where they have problems with anterograde memory, where they have problems with multitasking, where they can't multitask anymore, and they can't focus, worsening anxiety or PTSD. I had a patient whose anxiety got so bad that she was literally like a board in the room and couldn't move. It was debilitating to anything that she could do. These patients, these are nurses, people that work at the grocery store. I've had doctors and people who can't work or function in society anymore. Then there's the pulmonary stuff.

This is long COVID. This is something that I have become really passionate about ever since I started seeing some of these patients. With the history of the regulation of the stellate ganglion on the heart and in PTSD, somebody said, "Huh, let me see if this helps with long COVID." That case report showed that it did. The patient had a dramatic improvement in their symptoms. With what? With lidocaine. I don't want to get too much into it because I do have a paper that's submitted on a study on several patients that we did try to keep it very pure lidocaine only so that if this is something that does get published and, hopefully, that's what insurance companies need because let me tell you, private factors or anything to do with pain or with nerves, insurance companies, wow, they don't want to help you. They don't want to help the patients.

[Dr. Jacob Fleming]
No, they do not.

[Dr. Alexa Levey]
It's all considered experimental. If pain is also something you want to get into, get ready to do peer-to-peers. I will tell you, I have fought tooth and nail for a lot of my patients, and particularly, my long COVID patients. I am so happy every day that I did. Get ready for it because until you do more research, this is what's going to happen.

[Dr. Jacob Fleming]
Absolutely.

[Dr. Alexa Levey]
Anyways, stellates for that. Then eventually cryos for some, when some of them have blocks wear off. Some of them, I have one patient who's a year and two months out, his block is still working.

[Dr. Jacob Fleming]
Wow. It's really unpredictable. That's one thing about pain is even with something as simple as a knee injection or a hip injection, we can typically tell them, "Hey, you will get some relief from this, but for how long, I don't know." It's hard to say because clearly the benefit for some patients way outlasts the duration of the medication. There's certainly things that are much deeper to that. We talked about neuromodulation. Obviously, a block is not really neuromodulation, but there's something deeper there. We always have to be able to talk to the patients about not really sure how long it will last, but if it does come back, here's what we can do in terms of cryo and those kinds of things. I'm really interested about how multi, just multi-use, the stellate ganglion is. It does so many different things.

[Dr. Alexa Levey]
It's incredible.

[Dr. Jacob Fleming]
It's really amazing.

[Dr. Alexa Levey]
At one point, my partner, Dr. Zvavanjanja, who's amazing, he's one of my colleagues at UT, was like, "Levey, I looked at your schedule and it was stellate, stellate, stellate, stellate, stellate, stellate." Honestly, even if you're getting into pain, it's something that really opens a lot of doors because all medical ICUs have patients that go into refractory heart centers. Heart and vascular centers have people that go into refractory VTAC, and they are desperate. They've had multiple ablations, other things. If you're the person who can come in and do a stellate and then subsequently a cryo, you are really making a really, really big difference and adding a pillar to something that can help people.

That's what we're doing as interventional radiologists and just in general. I'm at the tumor ward today, and it was so cool as we're talking about all those recurrent sarcoma. "Oh, we can maybe do this, can we resect it, but it's such a mess." "Oh, I can do some targeted radiosurgery." I was like, "Oh, I could probably cryo that and it would be fine." Then we're talking about different treatments for things and how multimodal we have been able to do it. Now, patients, it's not, "This is the last choice." It's like, "This is one of many choices of things that you can do." That's the cool thing about what we do.

[Dr. Jacob Fleming]
One thing I want to ask is with the stellate ganglion being so important for so much regulation, what are the potential complications of blocking or ablating it? Are there any serious untoward consequences that you talk to the patients about as a result of this?

[Dr. Alexa Levey]
In general, it has to do with targeting. Before the advent of using ultrasound, which some pain physicians still don't, they use fluoro, complication rate was as high as 20% that something could happen. Because let's talk about the eloquent anatomy that is there, the vertebral artery, the carotid artery, the jugular vein, the inferior thyroidal artery. The lung is right there on top because I tend to aim for T, the anterior aspect of the origin of T1 versus anesthesiologists aim for T6. Guess what? Recurrent laryngeal nerve is there. The thyroid is there. You're a lot closer to the aspect of the esophagus. All these things, bleeds, strokes, hoarseness, pneumos, all that stuff, a lot of the complications can be significantly decreased just by using ultrasound. Using ultrasound allows you to mark your position. You can use lidocaine to hide or to set, to push things away. Actually, my favorite combination is using CT with ultrasound. You do a CTA, you map everything out, you draw a line where you want to stick, you place your probe on that line, and then you stick your needle in there. It takes two minutes, and it's fantastic and very quick. The results are usually immediate.

Also important to note with blocks, results are either immediate from the bupivacaine, or they slowly increase over the next 24 to 48 hours and peak at 72 and stay maintained once the steroid kicks in. Versus cryo, immediate. All those things caused by those complications are things I still talk to patients about. In reality, is it something that I wish I could find wood to knock on? I have nothing. I have my Peloton box, by the way. When we talked to Dr. Saad about what he has, he has his thing on kypho boxes. I have my thing on a Peloton box because you can't preach health if you're not a part of it.

[Dr. Jacob Fleming]
Yes. You're actually riding the Peloton right now as we speak, aren't you?

[Dr. Alexa Levey]
100%. Doing an Olivia workout. She's nuts. I forgot what we were just talking about.

[Dr. Jacob Fleming]
You actually got into the next question I was going to ask, which is the actual procedure of either blocking or ablating the stellate ganglion, which is great.

[Dr. Alexa Levey]
I still talk about all those complications, but I say they're at less than 2% risk. All the ones I've done, I probably had one retropharyngeal hematoma from a cryo, and that's it. The whole thing too is when you do a block, you use a 17-gauge needle. When you do a block, oh my gosh, we stick a 22-gauge needle in everything. Actually, when I tell patients, I was like, "Here, you see my PA right there? I could take the needle, poke her in the belly with it, poke her aorta about 10 times and say, 'Have a great day.'" She'd be a little upset at me because she's going to be sore, but ain't nothing going to happen. The safety profile of the needle we use, we do that for subarachnoid gastric nerve blocks and all that stuff. It's so safe. Is there any person that I wouldn't do a stellate on? No. I think it's probably one of the more safe procedures versus splanchnics. You're scanning by lungs and you're right there by the diaphragm and by the intercostal nerves and getting the right angles. You can actually cause a lot more harm, but a stellate?

[Dr. Jacob Fleming]
Got you. You mentioned Horner's earlier. Is that something that shows up in the context of these?

[Dr. Alexa Levey]
Yes. Usually, it's expected. It's actually funny. It's a lot more reported in the anesthesiology literature. I wonder if it has to do with getting a lot closer to the superior cervical ganglion because they're hitting it at C6 versus I'm hitting it at T1 because I would say rarely does it happen. Again, with my long COVID patients, about a third of them. Always something to talk about. When it comes up, it usually goes away after about a week.

[Dr. Jacob Fleming]
Got you.

[Dr. Alexa Levey]
It's almost a positive finding. They actually used to say when you're doing stellate ganglion blocks, and now I also can tell you it happens with cryos too, is the positive findings that you hit it. Horner's syndrome, unilateral, bilateral, or contralateral, don't specify, an increase in temperature on the ipsilateral side and a feeling of that increased temperature on the ipsilateral side are all positive findings that you actually hit it.

[Dr. Jacob Fleming]
Got you. That's really interesting because we think of those as being complications, things we don't really intend, but they are positive findings. These are expected outcomes really. That is really good to know. That's something that's good for the patient to know upfront.

[Dr. Alexa Levey]
Yes. You may look like you have a stroke, but you didn't. Actually, it's very important to warn the patient it's not a stroke. Now, if other things start happening, maybe go to the hospital.