Left or Right, Transradial Access for All.
Martinez CA, Cohen MG. Cardiovascular Division, University of Miami Miller School of Medicine, Miami, FL, USA.
“That which we persist in doing becomes easier, not that the task itself has become easier, but that our ability to perform it has improved.” – Ralph Waldo Emerson (1803–1882)
After Campeau and Kiemeneij published their successful series on diagnostic coronary angiographies and percutaneous coronary intervention (PCI), the radial artery has become the preferred vascular access site, especially in Europe, Japan, Canada and other regions. In the United States, transradial access has gained renewed momentum due to the recognition of access-site bleeding as a predictor of adverse outcomes after PCI, and the inception of dedicated micropuncture needles, hydrophilic-coated sheaths and hemostasic radial devices. Trans-radial access is associated with a significant reduction in access-related bleeding, improved patient comfort and lower costs in comparison with transfemoral access. Moreover, observational data suggest that transradial access is associated with a survival benefit among patients undergoing PCI. The recent RAPTOR trial demonstrated how operators can easily and safely shift their practice to routine transradial access with a minimal increase in procedure duration and radiation exposure in diagnostic, but not in interventional, catheterization procedures. However, transradial access demands a specific skill set that is usually acquired after a learning curve of approximately 100 cases and is associated with increased radiation exposure to the operator. An additional concern is the increased access failure rate of approximately 5–7% of cases, with the need for crossover to transfemoral access.
When the initial attempt to puncture the radial artery fails, the usual practice is to switch to transfemoral access, as most operators intuitively assume that the anatomical factors present in one arm would be present in the other. In addition, the uncomfortable position, leaning over the patient to reach the left wrist to manipulate catheters, and the additional radiation exposure may discourage many operators from attempting left radial access after failed right radial access. In general, left radial access is reserved for patients with previous coronary bypass surgery to facilitate imaging of the left internal mammary artery. In this issue of the Journal, Guédès and colleagues11 present their transradial catheterization experience applying the general strategy of crossing over to the contralateral radial artery when the homolateral radial approach fails. In this prospective observational cohort study, 1,826 patients who underwent transradial catheterization by 2 experienced operators had a very low transfemoral crossover rate of 1.2% after failed access in both radial arteries. The failure rate of the initial transradial attempt was 6.8% in the overall population, and 4.9% when post-CABG patients were excluded. In 60% of the cases, the procedures were diagnostic, 32% included ad hoc PCI and 8% were elective PCIs. The authors are to be commended for their detailed analysis of the causes of unsuccessful transradial attempts. Inability to puncture the artery, advance the wire or place the sheath were reasons for failed access in more than 50% of the cases. Other reasons for failed access included the inability to navigate the upper-extremity vasculature with the wire or the catheter (11%), the inability to selectively reach the coronary ostia (10%) and the inability to cannulate the contralateral internal mammary artery (27%). Independent factors associated with failure of radial access included the operator’s experience, presence of peripheral vascular disease, perceived difficult access and small radial artery size. In a previously published series of 2,100 PCIs, the most common reason for failure was the inability to reach the ascending aorta due to radial spasm, dissection or tortuosity. An additional reason for failure was the lack of guiding catheter backup support for PCI. Predictors of transradial failure were older age (> 75 years), female gender, prior CABG and short stature.
The recently presented TALENT study suggests that the left radial artery is an appealing vascular access alternative, especially for physicians learning the technique. The study randomized 1,540 patients to left or right transradial catheterization and demonstrated that left transradial access was associated with a reduction in fluoroscopy time and radiation exposure, driven exclusively by cases performed by trainees as primary operators. Of note, subclavian tortuosity, an important predictor of transradial access failure, was less common with left transradial catheterization procedures. The femoral crossover rates of approximately 1% in the TALENT study were very similar to the rates reported by Guédès and colleagues in the present issue of the Journal.
Whether left- or right-sided, it is without question that transradial access should be the default vascular access strategy in the catheterization laboratory. In cases of a small or nonpalpable radial artery, the ulnar artery offers an excellent alternative. Moreover, due to increased patient safety, transradial access should be a required curricular component of fellowship training programs and its use should become a quality metric for catheterization laboratories. The results of the current study are reassured by pointing out the important advantage of transradial access in decreasing vascular and bleeding complications; but more specifically, it encourages the alternative use of the contralateral radial artery prior to giving up on this approach.
It is important to emphasize that current vascular access data not only highlight the safety of transradial access, but also the limitations of current transfemoral access techniques. The femoral artery will continue to be used for structural heart disease interventions, placement of percutaneous left ventricular assist devices and complex bifurcation PCI. The use of micropuncture needles with real-time ultrasound guidance reduces the occurrence of vascular complications by more than 50%, decreases the time to sheath insertion and the number of access attempts. Therefore, as an integral vascular access strategy for the catheterization laboratory, the transradial approach should be primarily considered in all patients, and transfemoral access with ultrasound guidance should be reserved for those who are either not eligible for transradial access or need complex interventions with need for sheaths larger than 6 French.
J Invasive Cardiol. 2010 Sep; 22(9):398-9.