Ultrasound guidance, other techniques ensure transradial access safety in vascular procedures

HOLLYWOOD, Fla. — Ultrasound guidance and four other steps were identified as core factors for safely performing vascular procedures with transradial access by a speaker at the International Symposium on Endovascular Therapy (ISET).

“If you follow these five steps, they form the core to safely perform transradial access for noncardiac interventions,” Rahul S. Patel, MD, assistant professor of medicine at Icahn School of Medicine at Mount Sinai, said.

The first step is performing a Barbeau Test, which involves placing a pulse oximetry device on the patient’s thumb, he said.

Of the four possible outcomes, only a D-wave result, signifying loss of pulse tracing without recovery within 2 minutes, indicates the patient is not suitable for transradial access, he said, noting that this result only occurs in approximately 5% of patients.

A pre-dilation protocol involving lidocaine cream and nitroglycerin ointment may be appropriate in patients with small radial vessels, who are often younger women, according to Patel.

The second step is using ultrasound guidance to measure radial artery diameter, which indicates to the operator what size of sheath should be used. For example, the outer diameter of a standard 6F sheath is 2.6 mm, the outer diameter of a standard 7F sheath is 3.1 mm and the outer diameter of a thinner 6F sheath (Glidesheath Slender, Terumo) is 2.4 mm, Patel said.

To prepare the patient for access, the left arm, which Patel said he uses for all procedures below the diaphragm, should be elevated above the left groin, using a towel roll and arm bar if necessary.

A micropuncture using a single-wall technique over an 0.018-in. wire is recommended, according to Patel. The puncture should be made at a 30- to 45-degree angle, as complications can occur if the angle is too steep.

The puncture site should not be too close to the hand, as that may be more painful for the patient, and the sheath should be hydrophilic, Patel said.

Third, a “cocktail” of heparin 3,000 U, verapamil 2.5 mg and nitroglycerin 200 mcg should be delivered, according to Patel.

Fourth, a reverse-curve approach usually works well for navigating the descending aorta, Patel said. He noted his team most often uses a 110-cm 5F catheter (Sarah Radial, Terumo), but other feasible options include a 100-cm 5F catheter (Cobra, Terumo), a 125-cm 4F catheter (Tempo Aqua, Cordis), a 100-cm 4F catheter (Tempo, Cordis) and a 120-cm or 150-cm angled catheter (Glidecath, Terumo).

The last step is that during closure, the operator must ensure patent hemostasis, Patel said.

After achieving hemostasis, the operator should apply a pulse oximeter to a finger and observe, manually occlude the ulnar artery and wait 10 seconds to close after the waveform becomes evident.

Non-occlusive pressure should be maintained, and “you should be able to feel a distal radial artery pulse,” Patel said.

“Based on these steps, you can build all your interventions, including liver, renal and mesenteric interventions,” he said. – by Erik Swain

Reference:

Patel RS. Access and Closure: Session 1. Presented at: the 2018 International Symposium on Endovascular Therapy (ISET); Feb. 3-7, 2018; Hollywood, Fla.

Disclosure: Patel reports he is a consultant for Medtronic and Surtex Medical and a speaker for Penumbra and Terumo.