The use of transradial (TR) access for the purpose of diagnosis and intervention in the arterial system is a well-established concept, particularly in coronary angiography, with many distinct advantages over conventional transfemoral (TF) access. The first series of 100 coronary angiographic procedures performed via TR access, published by Campeau in 19891, demonstrated 88% technical success rate and a 6% asymptomatic radial artery occlusion rate. Further experience and data accumulated with the first TR angioplasty procedure in 1992 and the first TR coronary stent placement in 1993. TR access for coronary artery interventions in the United States has grown exponentially over the past few years with the proportion of transradial percutaneous coronary interventions (PCI) procedures increasing from 1.2% in the first quarter of 2007 to 16.1% in the third quarter of 20122. And yet, its usage is largely absent in the interventional radiology and vascular surgery communities.

Reasons for this include a lack of appropriate training and equipment, but the potential advantages of TR over TF access are abundant in both coronary and non-coronary applications. Firstly, the radial artery is more superficial than the femoral artery without surrounding neurovascular structures susceptible to injury. In addition, any sustained arterial damage is significantly less detrimental because of the hand's dual arterial vascular supply. In addition, the radial artery is readily compressible regardless of the patient's body habitus. This compressibility has been shown to decrease the incidence of post-procedural bleeding complications as well as cardiac mortality during PCI3,4,5. In addition to patient safety, there are numerous benefits to overall patient comfort and convenience. For one, after TR access, patients may sit up in bed and ambulate immediately with faster discharge to home. In one randomized trial, Cooper et al demonstrated a strong patient preference, improved quality-of-life metrics, and decreased hospital costs for TR over TF access during cardiac catherization6. These benefits have yet to be empirically demonstrated for non-coronary applications like transarterial hepatic embolization. Even so, these potential benefits are of even greater importance in the patient population undergoing chemoembolization/bland embolization given the chemo/bland embolization's association with nausea and emesis post intervention.

Ultimately, complications with TR approach have proven rare in both coronary and noncoronary applications. Most commonly, a local small hematoma may develop with mild pain, usually treated with NSAIDS if necessary. Despite meticulous hemostatic technique, radial artery thrombosis may occur. Nevertheless, this thrombosis almost always remains asymptomatic7, at least partially because a modified Allen's test is performed before all procedures using TR access. The Allen's test is a clincal examination technique that determines the presence of dual arterial supply to the hand and palmar arch patency in the event of radial artery occlusion. Additional possible complications of TR access include radial artery pseudoaneurysm, spasm, dissection, digit ischemia, as well as cerebral infarction, but all of the following have proven to be extremely low incidence particularly with the usage of intraprocedural heparinization and vasodilators, which are included in our procedure protocol.

Finally and increasing more importantly in the modern era of health care reform, TR access offers many benefits to hospital costs and patient satisfaction. Many studies have demonstrated decreased costs associated with TR versus traditional TF access5,8,9, primarily due to the nonutilization of arterial closure devices and decreased readmission for bleeding complications. International studies have long promoted TR access as a feasible, safe, and well tolerated method for performing hepatic transarterial chemoembolization10,11. In a recent series performed in the United States, technical success was obtained in all procedures. Furthermore, 100% of patients who underwent both TF and TR access preferred TR over TF access12. Our study seeks to further establish TR arterial access as a viable and typically preferable method for performing hepatic transarterial embolization as well as refine patient suitability criteria for TR access.