The study was presented at the Society of Interventional Radiology’s annual scientific meeting (28 February–5 Atlanta, USA). Aaron Fischman, Department of Interventional Radiology, Icahn School of Medicine at Mount Sinai, New York, USA, spoke to Interventional News.
“About three years ago, we had not carried out any cases using the transradial approach. In cardiology, there is a vast body of literature regarding this access route. Nearly every paper that has been written on radial access has a signal that it is superior to femoral access with regard to bleeding rates, patient satisfaction, safety and complications so we have been trying to parse out which parts of interventional radiology that could translate to. For me, the benefits of transradial access fit into interventional radiology’s mission to provide the least invasive, most cost-effective and highest quality care and that is why I am interested in it,” he said.
Fischman and colleagues note that transradial access has been shown to decrease complications when compared with transfemoral access in coronary intervention. Transradial access for peripheral and visceral interventions is less common but has been reported to offer comparable therapeutic efficacy as transfemoral access in chemoembolization with lower overall access-site complications. Additionally, the lack of need for an arterial closure device in transradial access affords patients faster time to ambulation and discharge.
The investigators retrospectively reviewed 1004 procedures performed in 668 patients undergoing transradial access from April 2012 to October 2014. Procedures included: chemoembolization (n=371), Y90 mapping (n=249) and infusion (n=168), renal/visceral intervention (n=104), uterine artery embolization (n=65), peripheral intervention (n=37), endoleak (n=8), and other (n=2).
The authors noted that a pulse oximeter was used on the ipsilateral thumb to confirm dual circulation and patency of the palmar arch (Barbeau Test). They further noted that ultrasound of the radial artery verified adequate vessel size. Transradial access contraindications included: radial artery <2mm and Barbeau D waveform. After radial artery puncture, a hydrophilic radial access sheath (Glidesheath,Terumo Interventional Systems) was placed and 3000U heparin, 2.5mg verapamil, and 200mcg nitroglycerin was given to minimise vascular trauma. Following the procedure, a radial compression device, TR band (Terumo) was used for haemostasis. Procedural details and 30-day adverse events were evaluated using CTCAE v4.0.
The researchers reported that there was 99.4% (998/1004) technical success obtained via transradial access, with six cases requiring transfemoral access crossover (0.6%). Overall major adverse events were 0.3% including one large haematoma requiring crossover to transfemoral access, one pseudoaneurysm requiring intervention, and one verapamil-induced seizure. The minor adverse event rate was 3.2% and included radial artery occlusion (n=11, three crossover), haematoma/bleeding (n=9), radial artery thrombosis (n=five, one crossover), arteritis (n=three), pain/numbness (n=two), and severe vasospasm (n=two, one crossover). “All minor adverse events were either asymptomatic or managed conservatively. There were no additional adverse events at 30 days,” the authors wrote.
Different patient experience
Fischman emphasised that from a patient’s point of view, the transradial approach is very different from the transfemoral approach. “Quite often patients can have sensitivity in the groin, and some do not like being exposed in that area. The femoral artery is deeper [than the radial artery] so there can be more pain with femoral access. We have learned that the approach from the wrist is perceived by patients as less invasive and less painful. Patients do not have to keep their leg flat for three hours and can literally walk out of the room. They can also recover sitting in a chair, rather than on a hospital bed.
“When I was trained, I did not think about the access route, we used the femoral route and that was it. Now, we think about which access site is most suitable technically for the procedure and for the individual patient. In morbidly obese patients, for example, the transradial approach is significantly easier and safer. The adoption of the transradial approach in interventional radiology is very low. In many countries, nearly 80 to 90% of percutaneous coronary intervention is via the transradial approach. We want to teach people how to do this and what we have learned as there is some nuance to this,” he said.
Currently, medical devices are not optimised for transradial access. “We are collaborating with industry to design a specific interventional radiology approach for transradial access. We need many types of devices that are not optimised; three that would be helpful right away are: longer catheters with different shapes; stents; and balloons,” Fischman said.