Transradial access (TRA) for cardiac catheterization, angiography, and intervention has well-documented advantages over the transfemoral approach.¹ Mastering TRA requires the development of complementary skills including precise radial artery puncture, prevention and management of radial artery spasm, a thorough understanding of the vascular anatomy of the arm and associated variants, catheter manipulation for selective coronary cannulation, and maximization of support during percutaneous coronary interventions (PCI).² In this chapter, we will review unique aspects of TRA. We will also provide tips-and-tricks on how to manage common and not-so-common difficulties encountered during TRA.

A dedicated radial catheterization laboratory requires a team effort. Education of the catheterization laboratory staff is critical to ensure that every staff member is well versed in procedural requirements. The procedure setup is relatively simple. Use of an arm board is helpful to enhance patient’s comfort and to facilitate the task of the physician performing the procedure (FIGURE 4.1). Previously, tests to evaluate the hand collateral circulation such as the Allen test and modified Barbeau test were suggested before TRA³ (FIGURE 4.2). However, given the extensive collateral circulation, the low rate of radial artery occlusion (RAO), and the extremely rare incidence of ischemic complications, TRA catheterization can be safely performed even in borderline cases, and these tests are no longer considered necessary.⁴ While the right radial artery ergonomically works best with the configuration of most catheterization laboratories (FIGURE 4.3), the setup for left TRA is just as easy (FIGURE 4.4). Left TRA is the preferred approach in various circumstances including the following: (1) the presence of a left internal mammary graft; (2) elderly, short, or female patients in whom tortuous anatomy is anticipated; and (3) the need for lower extremity angiography or intervention, especially in taller patients, because it is shorter and straighter to reach the lower extremity circulation.¹¹

It is important to understand the vascular anatomy of the wrist, arm, and forearm (FIGURE 4.5). The radial artery lies between the tendons of the brachioradialis and flexor carpi radialis over the prominence of the radius. The artery can be accessed with either an anterior wall puncture or a through-and-through back wall puncture (FIGURE 4.6). Vascular ultrasound can be helpful⁶ (FIGURE 4.7), and alternatively, ulnar access (FIGURE 4.8) and radial artery access in the anatomic snuffbox have been recently described (FIGURE 4.9). This last approach is particularly convenient for left TRA.

Right-sided heart catheterization can be performed via the arm veins.⁷,⁸,⁹ For certain patients, this may be the preferred approach. The bleeding risk is minimized for patients that are coagulopathic, such as end-stage liver disease patients, and the brachial vein access for right-sided heart catheterization can also overcome the need to halt anticoagulation, as the venous system is easily compressible in the antecubital fossa.¹⁰ Having the nurse place a heparin lock in the forearm, which can then be used in the catheterization laboratory to exchange for venous sheath, can save time and improves catheterization laboratory efficiency. Contraindications to brachial vein approach include obstruction to radial drainage, breast surgery, trauma, and superior vena cava (SVC) disease. Caution should be exercised in patients with prior brachial cutdown, arrhythmia devices, or no visible veins. See FIGURES 4.10, 4.11 and 4.12.