Ultrasound Optimizes Radial Access in Randomized Trial

San Francisco, CA—Ultrasound guidance improves the success and efficiency of radial artery cannulation, according to results of a randomized, multicenter trial presented at TCT 2013.

Arnold Seto, MD, of Long Beach Veteran’s Affairs Medical Center in California, and colleagues randomly assigned 473 patients at four centers to undergo radial artery needle insertion using either palpation (n = 237) or real-time ultrasound guidance (n = 236).

Ultrasound reduced the number of attempts needed to insert the needle as well as the mean and median times to sheath insertion. It also increased the odds that the first pass would be successful (see Table).

Table. Palpation vs. Ultrasound Guidance for Transradial Catheterization

Ten patients required crossover to ultrasound guidance after 5 minutes of failed palpation attempts, of whom nine had successful sheath insertion with ultrasound. Fewer ultrasound-guided procedures were categorized as “difficult,” defined as needing more than five insertion attempts (6 vs. 44; P<.001). Patient-reported pain scores were similar for palpation and ultrasound, as were rates of operator-reported spasm, crossover to other access sites, and bleeding complications.

Ultrasound not required in every case

Transradial access for cardiac catheterization is becoming more popular thanks to mounting evidence that the method improves outcomes, but the initial arterial cannulation can be difficult in some circumstances.

“Ultrasound guidance may be particularly useful in those patients with weak pulses, obesity or hypotension,” Seto said. Operators who have less experience with the radial approach may also benefit from using ultrasound, he added, noting, “But our study demonstrates that, even with experienced transradial operators, ultrasound had an incremental benefit.”

Another study investigator, Zoran Lasic, MD, of Lenox Hill Hospital in New York, added that ultrasound may also be particularly useful in patients with very small and muscular arteries.

However, Seto stressed that, without data showing obvious clinical benefit, ultrasound guidance cannot be considered standard of care; such a benefit would be difficult to demonstrate given the generally very low complication rate with radial access. A reasonable approach for most operators may be to use palpation for one to three unsuccessful attempts before trying ultrasound. “Radial access with palpation only becomes more difficult after a few failed attempts as the artery begins to spasm,” he said.

According to Lasic, the study results suggest that ultrasound could help guide other types of interventions. “In the modern era, interventional cardiologists should develop manual dexterity in using ultrasound guidance for vascular access,” he said, citing potential for femoral access in TAVR and for popliteal artery and posterior tibial artery access in retrograde chronic total occlusion PCI.

Disclosures:

Drs. Seto and Lasic report no relevant conflicts of interest.