PCI via Ulnar Artery Equally as Safe and Effective as Transradial Approach

Patients undergoing PCI via the ulnar artery fare just as well as those treated with the radial approach, although there is a higher rate of access-site failure with the ulnar artery that is likely attributable to a learning curve among operators, according to the results of a new meta-analysis.      

Overall, there was no significant difference in the risk of major adverse cardiovascular events, defined as MI, stroke, urgent target vessel revascularization, or death, among patients treated with the transulnar or transradial approach.

In terms of safety, there was no excess risk of bleeding or hematoma with transulnar PCI compared with radial access, nor was there any additional risk of arterial occlusion. Access-site failure, though, was more than twice as high among patients undergoing PCI via the ulnar artery (OR 2.63; 95% CI 2.07-3.34).

Senior investigator Astin Lee, MD (Wollongong Hospital, Wollongong, Australia), told TCTMD the meta-analysis provides reassurances that the ulnar artery is a “viable and safe alternative to the radial or femoral artery,” although more information will be needed as interventional cardiologists become more familiar with cannulating the ulnar artery.

The meta-analysis, published online February 1, 2018, ahead of print in Catheter and Cardiovascular Interventions, included six studies with nearly 4,800 patients. It showed that ulnar access was not associated with increases in fluoroscopy time, contrast load, or access time. There was a nonsignificant trend toward increased crossover to radial access when using the ulnar artery.     

Lee said the ulnar artery can be considered an alternative to the radial artery in a number of situations, including cases in which operators need to preserve the radial artery for bypass grafts or arteriovenous fistulae for hemodialysis in patients with poor kidney function. Additionally, severe radial artery tortuosity or spasm and known radial artery occlusion might be other reasons physicians opt for the ulnar artery. The ulnar artery also tends to be larger than the radial artery.

Mamas Mamas, BMBCh (Keele University, Stoke-on-Trent, England), who was not involved in the analysis, said transulnar PCI makes up about 5% of his workload. He noted that more and more operators are using routine ultrasound to assess vessel diameter, and if the ulnar is shown to be larger than the radial artery, it might be a better option, particularly if a large-bore guiding catheter is needed. In his practice, he will perform transulnar PCI if the radial artery is blocked or in hemodynamically unstable patients who have an ulnar artery that is more palpable.

“The ulnar is deeper than the radial and often more difficult to cannulate for this reason,” Mamas told TCTMD. “Many operators aren’t used to using ultrasound, which invariably helps. It comes down to the learning curve. If you only use the ulnar when you run into problems with radial, you won’t get the necessary experience in using this access site.”

Rather than wait for such already challenging patients, Mamas recommends operators gain experience in less difficult cases so they have the skills when needed. “For me, it is about personalizing your approach for each patient based on the relative size of each vessel and your own experience with each access site,” he said.

Lee noted there are some risks to transulnar PCI, which include potentially damaging the ulnar nerve given its proximity to the artery. “The ulnar nerve lies just medial to the ulnar artery, so cannulation of the ulnar artery should ideally be done from the lateral side,” he said in an email. Pseudoaneurysm is also a potential risk given that hemostasis is more difficult because the ulnar artery runs deeper and has no immediate bony structure underlying it. Given the challenges of hemostasis, Mamas recommends closer postprocedural monitoring in transulnar PCI patients.

Regarding the higher rate of access-site failure observed in the present analysis, Lee said the result wasn’t too surprising given that there is a learning curve associated with transulnar PCI. Still, Lee said transulnar PCI is not a more complicated procedure when performed by experienced radial operators. In Lee’s practice, less than 10% of patients undergo PCI via the ulnar artery, although he said they have been palpating the ulnar artery more frequently. “And if the ulnar pulsation is more obvious than the radial pulsation, then we may attempt to cannulate the ulnar artery,” he said.