International Stroke Conference
February 19–21, 2020

Kat Dakay, DO

Use of the transradial technique as an alternative to traditional femoral access in neuroendovascular procedures has increased substantially over the last few years after studies have demonstrated its advantages and lower risk of access site complications.[1]   

However, there is a learning curve that one must traverse when adopting the transradial approach. This year, the International Stroke Conference dedicated a symposium to a multifaceted discussion about the benefits, challenges, and potential complications unique to transradial access. 

The session was moderated by Dr. Tudor Jovin and Dr. Nathan Manning, and speakers included Dr. Michael Levitt, Dr. Eric Peterson, Dr. Marios Psychogios, and Dr. Brian Snelling. Some major topics discussed:

1. Why go radial?

There are several reasons to consider utilizing the transradial approach. Dr. Peterson discussed one major reason, patient preference — with a transradial approach, there is no need for patients to lay flat postoperatively, which can make even small tasks like using the restroom awkward and cumbersome. Increased awareness of the transradial method by the general public has led to increasing patient requests to use this approach. Anecdotally, as a fellow explaining and obtaining consent for diagnostic angiograms, many patients have said to me, “I really hope you can use my hand instead of the leg.” As the popularity of transradial access in both cardiology and neuroendovascular procedures grows, this is likely to become more common. Objectively, one study demonstrated that 24/25 patients who underwent prior transfemoral cerebral angiography and subsequently underwent transradial angiography preferred the radial method.[2] Another reason Dr. Peterson discussed is that in patients with obesity or significant arch tortuosity, transfemoral access can prove challenging and the radial approach may be easier in selected cases. Lastly, and probably the most compelling and important reason, which both Dr. Peterson and Dr. Levitt discussed, is that it is safer. Multiple cardiology trials have demonstrated that transradial procedures are safer than transfemoral procedures with an overall lower risk of major complications and mortality.[1, 3] 

2. How do I manage catheter-induced spasm? What if the catheter gets stuck?

The radial artery is particularly prone to vasospasm, which can be induced by the catheter; using topical lidocaine cream followed by local infiltration of lidocaine anesthetic prior to puncture, infusing a spasmolytic cocktail intra-arterially once access is obtained can help reduce the risk.[4] If a catheter gets stuck due to vasospasm, deepening sedation, inflating the blood pressure cuff for five minutes and then deflating it, using warm compresses, and administering additional spasmolytic can help. Concomitant compression of the ulnar artery can also assist in relieving vasospasm. 

3. Which catheters and sheaths are preferred?

Dr. Peterson noted that they typically favor a Glide catheter, 5 French for diagnostic procedures. Catheters currently on the market are not specifically designed for radial use and are only hydrophilic on the distal portion, which does not prevent spasm in the radial artery which contacts the more proximal portion of the catheter. A designated radial catheter, the Rist, was recently cleared by the FDA.[5] Dr. Snelling and Dr. Psychogios discussed various approaches for interventional procedures. Unlike in the femoral artery, which can take an 8 Fr (or larger) sheath, there are no 8 French radial sheaths. Thus, for interventional procedures requiring a guide catheter, they typically place a 6 Fr or 7 Fr sheath and exchange for a guide catheter once access to the proximal target vessel is obtained. However, for many interventions such as embolizations or coiling, a 6 French sheath should be sufficient.

4. Do I need to do a Barbeau or Allen test?

Radial artery occlusion occurs in 1-6% of transradial access cases, Dr. Levitt noted, but due to the rich vascular supply, it is typically asymptomatic. A large cardiology study showed no hand ischemic complications in a large cohort of patients who underwent transradial access, including patients with intermediate or abnormal Allen test results.[6] The SNIS Standards and Guidelines committee does not recommend the use of these tests to decide eligibility for transradial access.[7]

5. What about distal radial access? How does it compare to proximal access, and how do I close a distal radial arteriotomy?

Many centers, including ours, are using distal radial access for diagnostic procedures, and using the proximal radial artery to re-access if the patient needs a subsequent intervention. In addition, the superficial palmar branch is given off proximal to the snuffbox/distal radial puncture, further reducing complication risk. There is a designated distal closure device, the PreludeSYNC radial compression band, used to close snuffbox radial punctures. The TR band is commonly used to close proximal radial access.

6. What about using the brachial artery if I can’t access the radial artery?

There is a higher risk of ischemic complications using the brachial artery compared to the radial artery, as there are less robust collaterals; the consensus was that this is not an ideal access site given the risks. The SNIS Standards and Guidelines currently recommend against trans brachial access as a primary access site.[7]


1.           Romagnoli E, Biondi-Zoccai G, Sciahbasi A, Politi L, Rigattieri S, Pendenza G, et al. Radial versus femoral randomized investigation in st-segment elevation acute coronary syndrome: The rifle-steacs (radial versus femoral randomized investigation in st-elevation acute coronary syndrome) study. J Am Coll Cardiol. 2012;60:2481-2489

2.           Satti SR, Vance AZ, Golwala SN, Eden T. Patient preference for transradial access over transfemoral access for cerebrovascular procedures. J Vasc Interv Neurol. 2017;9:1-5

3.           Valgimigli M, Gagnor A, Calabro P, Frigoli E, Leonardi S, Zaro T, et al. Radial versus femoral access in patients with acute coronary syndromes undergoing invasive management: A randomised multicentre trial. Lancet. 2015;385:2465-2476

4.           Brunet MC, Chen SH, Peterson EC. Transradial access for neurointerventions: Management of access challenges and complications. J Neurointerv Surg. 2020;12:82-86

5.           Today E. Fda clears rist neurovascular’s rist cath for radial access. 2020

6.           Valgimigli M, Campo G, Penzo C, Tebaldi M, Biscaglia S, Ferrari R, et al. Transradial coronary catheterization and intervention across the whole spectrum of allen test results. J Am Coll Cardiol. 2014;63:1833-1841

7.           Starke RM, Snelling B, Al-Mufti F, Gandhi CD, Lee SK, Dabus G, et al. Transarterial and transvenous access for neurointerventional surgery: Report of the snis standards and guidelines committee. J Neurointerv Surg. 2019

Edited by Blogging Stroke senior blogger Gurmeen Kaur, MBBS.