Updated: Jul 16, 2019
Transradial access (TRA) has been shown to improve discharge and recovery times when compared to transfemoral access, though complications may arise. These complications include stroke and difficulties removing radial access devices due to vasospasm. TRA expert Dr. Aaron Fischman discusses complications related to radial access as well as ways to circumvent these problems.
The BackTable Brief
Choosing the right radial artery cocktail prevents vasospasm; a radial artery cocktail of 2.5 mg verapamil, 200 mcg nitroglycerin, and 3,000 units of heparin is preferred by Dr. Fischman.
Despite the use of a radial cocktail, severe vasospasm can occur and may prevent the removal of the access sheath. Always use a hydrophilic sheath during transradial access and wet the sheath before insertion to activate the hydrophilic coating.
Severe vasospasm may result despite preventative measures. Do not attempt to remove the sheath with increased force if resistance is met during sheath removal. Forceful traction can injury the radial artery. Ensure the patient is heavily sedated, administer additional nitro, and in severe cases consider using an up-and-over approach from femoral access to deliver vasodilators proximal to the site of spasm.
Dr. Fischman educates patients on the increased possibility of stroke when performing radial versus femoral access procedures; stroke is possible with either access site, yet the incidence may be slightly increased for transradial procedures.
Minimize the possibility of vertebral artery trauma by removing the catheter over-the-wire rather than pulling the catheter and wire together.
Photo Credit: Dr. Ari Isaacson
Disclaimer: The opinions expressed by participants of the BackTable Podcast belong solely to the participants, and do not necessarily reflect the views of BackTable.
What is the best radial artery cocktail for transradial access procedures?
Regardless of the radial artery diameter, sheath placement within the artery leads to vasospasm. A radial artery cocktail minimizes the degree of vasospasm permitting easier removal following the transradial procedure. A radial artery cocktail consisting of 2.5 mg verapamil, 200 mcg nitro, and 3,000 units of heparin is preferred by Dr. Fischman.
[Chris Beck] ... Thinking about other things that can be a little, maybe daunting, about radial access is, we hear a lot about vasospasm. Miraculously, we're probably 30 minutes in and we haven't actually mentioned the radial cocktail obligatory. You want to talk about that a little bit here?
[Aaron Fischman] Sure. The cocktail is something where everybody has a different one. People always ask about the cocktail we use. We talk about this when we do courses. It's pretty simple. We use heparin, nitroglycerin and verapamil. The doses are randomly picked, really, because when we first started doing this, I went on a website called Transradial University and I just looked at different cocktails that cardiologists were using at the time, and I really just picked something that I thought was easy for our nurses to draw up, and I knew that our verapamil came in 5 milligram vials. I said, "Why don't we just use half of that?” And then we use a little bit of nitro, around 200 nitro, then I use 3000 of heparin. You can use whatever you want to be honest. I think using heparin is pretty important, and nitro I think is really important too. With verapamil, I know a lot of operators don't use a calcium channel blocker. There are cardiologists that instead of verapamil will use nicardipine. Definitely cost differences there. You have to look and see what's easier for you. You definitely need to use something. It's not like the femoral where you just put the catheter in. You really need to use something that vasodilates and tries to reduce vasospasm, because this vessel is not a big vessel. Even somebody who has a three millimeter radial, which for the radial is a big vessel, putting in a sheath is going to create a lot of vasospasm.
How do you manage severe radial artery vasospasm?
Severe vasospasm of the radial artery may occur when attempting to remove the vascular access sheath; using a hydrophilic sheath is the most important way to minimize the risk of vasospasm, says Dr. Fischman. In cases where the sheath is really stuck he suggests starting with additional nitro and ensuring the patient is heavily sedated. An additional option is to use up and over access to deliver vasodilators to the artery, proximally.
[Chris Beck] I feel like vasospasm is something that gets talked about a lot. I'm talking about the vasospasm that you might see in a conference where it's vasospasm that's so intense you can't pull out the catheter. Have you had that happen to you?
[Aaron Fischman] Yeah. There are the very rare cases where you have severe vasospasm. Number one is making sure you're using a hydrophilic sheath. That will come out even with severe vasospasm. We're talking about the one and a thousand type cases where the catheter sheath is really stuck. What you do is you take your catheter out if you can, and if the sheath is stuck, you need to give more cocktail. I'll usually start with just nitro, and give a lot of nitro until I feel like I can't give much more, and you wait. You really want to make sure that the patient is heavily sedated. You don't want to rush. You don't want to just pull the catheter or pull the sheath out if it's stuck. You want to really sedate the patient so they relax a little bit. Then wait. If it takes an hour to get the sheath out, it's better than injuring the vessel. If that doesn't work, the other option is to even access the groin and come up from below and deliver some of those vasodilators directly into the vessel from above. That sometimes helps. I've never had to do that, but I know people that have. Then in a rare scenario you could give general anesthesia and that's not something that I've ever had to do, but I know people that have stopped before. They've done that, and they've pulled even harder on the sheath and they've injured the vessel that way. There's a lot of different ways to deal with that. If it happens, the most important thing is to not rush and to not just pull the sheath out.
Minimizing the Risk of Stroke During Transradial Access
Although rare, reports of stroke associated with radial access have occurred. When discussing femoral versus radial approaches, Dr. Fischman educates patients about the potential increase in stroke incidence associated with transradial access. To minimize chances of vessel trauma and the possibility of stroke, he removes all catheters over-the-wire rather than pulling the catheter with the wire. Removal of the catheter over a wire may prevent accidental trauma to the vertebral artery.
[Chris Beck] Okay. Good tips. One of the things that also gets discussed by people who are not comfortable with radial access is a stroke. It's reported in the cardiology literature. Maybe talking about the literature a little bit, then also anecdotally, how you feel about that? Do you counsel your patients regarding it?
[Aaron Fischman] Yeah. This is something that comes up almost every time you have a discussion about radial access in a meeting. It's not something to take lightly. There have been reports of stroke in the literature, and there are even reports that I've heard about outside of the literature that have not been reported, but people talk about it. Really what it comes down to is, yeah, we could look at the cardiology literature and compare right radial versus left radial, and femoral versus radial, but really doesn't apply to us because we're not really accessing the ascending aorta. We're accessing the descending aorta. The data from cardiology is not super relevant for us. The only vessel that we're crossing, really, from the radial approach is left vertebral. If you remember that paper from Miami that looked at an 89-year-old gentleman who had a Y90 from the radial approach and had multiple catheter exchanges and developed the posterior fossa stroke. You have to wonder whether that was a good patient for radial access. The question is, "Well, should you screen people for a disease in their arch?" I don't do that typically, but I use common sense. If I know somebody who's elderly, and I know that they have a lot of atherosclerotic disease. Again, a lot of the patients that we're doing do not have that, right? Chemoembolization patients, fibroid patients … they're not always those with severe atherosclerotic disease. You have to think about that. If you encounter somebody who you think might be in that category, you have to really think about whether radial access is the right way to go. Do I counsel patients? Absolutely. A great example would be a prostate embolization case. These are older men, right? They come in and they say, “Well, can you really reach from the wrist?" I said, "You can absolutely reach." And they said, "Well, why would anybody want to do it from the groin?" Then we have that discussion. I tell them stroke is something that can happen regardless of the approach, but it could potentially be higher from the radial approach because we're crossing that one vessel. There are people who form femoral catheters in the arch. I would argue that if you're one of those types of operators that does that, you're probably creating more trauma to the arch than if you were doing a radial cannulation. You have to think about your practice and what you do, but you always have to be vigilant when you remove the catheter. I always remove the catheter over a wire. I don't pull the catheter on a wire because I think that can also create trauma to the vertebral if you're not careful.
---------- Podcast Participants:
Dr. Aaron Fischman is a practicing interventional radiologist at Mount Sinai Hospital New York.
Dr. Chris Beck is a practicing interventional radiologist with Regional Radiology Group in New Orleans.
Cite this podcast:
BackTable, LLC (Producer). (2018, June 27). Ep 30 – Transradial Access: Basic to Advanced [Audio podcast]. Retrieved from http://www.backtable.com/podcasts
The Materials available on the BackTable Blog 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.