PCI—accessing the radial artery

Learn about the benefits of utilizing radial access in PCI.

David G O’Brien, MD FRCP
David G O’Brien, MD FRCP
3rd Jul 2019 • 4m read

Radial access is gaining popularity among interventionists—but why? In this video, Dr O'Brien looks at the advantages of using radial access in PCIs, as well as the challenges of doing so. He will also provide a step-by-step approach to safely performing a radial artery puncture.

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Video Transcript

[00:00:00] Radial access has a number of benefits and is gaining popularity across the globe. At the institution where I work, we're predominantly radial operators, and the majority of procedures are performed using radial access. As you've heard, one of the biggest benefits to using radial access is easier mobilization and ambulation post-procedure. Radial access also decreases the requirement for patient beds due to radial lounges

[00:00:30] leads to fewer bleeding complications, and the radial arteries are less likely to be affected by atheromatous disease than femoral arteries. The downside, as we've also heard, is their limited size especially in smaller and female patients which then may subsequently limit the size of equipment which can be used. As a reminder, intra-aortic balloon pumps and impella devices can only be inserted from femoral access sites. There are several challenges in radial access.

[00:01:00] Radial spasm can occur even with the most experienced of PCI operators. I would advocate when starting out that to minimize the risk, use a radial cocktail. Negotiating through radial cocktail side branches and tortuosities can also make radial access difficult, as well as negotiating subclavian and brachiocephalic tortuosities in particular. Manipulating into the ascending aorta can be very difficult in certain cases. For example, in Arteria

[00:01:30] Lusoria where the right subclavian artery joins the aorta distal to the left subclavian artery. If you cannot negotiate from the radial artery due to spasm, loops, or other anatomical issues, it's possible to consider ulnar artery access instead. This tends to be straighter but is often more deeply seated in the forearm and closer to the median nerve, so it tends to be used less as a routine than the radial approach. In this demonstration,

[00:02:00] we see how I perform a radial artery puncture and sheath insertion. A small amount of local anesthetic is injected subcutaneously over the site of the radial artery just proximal to the flexor retinaculum. Enough is required to make the procedure pain-free but avoid too much as it can make feeling the radial artery difficult or cause spasm. I tend to make a small cut in the skin with a scalpel to make

[00:02:30] manipulation of the needle and subsequent sheath insertion easier. Others make puncture first and either trying to pass the sheath without a skin cut or make the skin cut carefully once the wire's in the vessel. Once I've made this small skin cut, I puncture the radial artery with a needle at about 45 degrees. When I see flare of arterial blood from the needle, I insert the wire carefully. If there's any resistance as the wire exits the needle, the needle should be gently withdrawn

[00:03:00] and the wire advanced again. Once the wire is in position, the sheath is inserted using a standard Seldinger technique over the wire with a gentle twisting action to facilitate passage. Resistance to passage is generated largely by the sheath passing through the skin and subcutaneous structures, hence, my skin neck previously.

[00:03:30] Once the sheath is in situ, I tend to fix it down with a dressing which should ideally incorporate the sidearm of the sheath to prevent it inadvertently being pulled out. If you cover the whole sheet with the dressing, as I do, remember to make a slit in it over the hemostatic valve so that you can still insert catheters. We tend not to routinely take radial angiograms as contrast in the radial artery is quite irritant and can cause the patient some discomfort. If it's difficult to [00:04:00] advance the catheter for any reason, then it's useful to take an angiogram to ensure there are no radial loops or that you have not entered a small branch and to determine the best way of proceeding without causing any damage to these often relatively small vessels. Aim to puncture just proximal to the flexor retinaculum. Aim to puncture at not too steep an angle as this can make advancing the wind difficult and more likely to enter the intima of the vessel. If the wire won't

[00:04:30] advance, it's likely that you may be advancing the wire into the back wall of the vessel. Try to withdraw the needle slightly whilst gently testing if the wire will advance or if this fails and blood still comes out of the needle, gently alter the angulation of the tip of the needle bevel and try again with the wire. Remember, the angle approach affects the chances of successful puncture in the radial artery much more than the femoral artery as it's a much smaller diameter vessel.

[00:05:00] Pull back gently if the wire fails to advance and vary the angle of the needle in two planes if it still won't go as you may not have punctured the vessel centrally. Turn the wire slightly if it advances easily at first and then stops, it may be that it's just entered a small branch. Never force the wire against resistance. It's not in the correct place if it doesn't pass easily. In this case, a radial angiogram was obtained via the sheath

[00:05:30] as it proved impossible to advance the catheter up the arm and the patient experience discomfort. The puncture was uncomplicated and blood aspirated normally out of the radial sheath sideboard. The angiogram shows the radial artery loops over before it joins to become the main brachial artery. Using a coronary angioplasty wire, it was possible to steer the wire around the radial loop and into the brachial artery. You can really see when the wire is passed

[00:06:00] just how loop the artery is at this point. The wire then enables the loop to be gently straightened out to allow the subsequent passage of the catheter up the arm and the remainder of the procedure was uneventful.