Access, Radial Artery

With the introduction of various catheters designed for radial access, the radial artery access has been gaining popularity recently. The Simmons catheters are typically the go-to choice for selecting target arteries.

Tips and Tricks

Medicine

• A small amount of local anesthetic is extremely useful in an awake patient to mitigate the pain caused by needle puncture and sheath placement
• Spasmolytic cocktail is typically composed of two vasodilators and heparin
  • 200-400 mcg of nitroglycerin
  • 2.5-5.0 mg of verapamil
  • 2,000 units of heparin
• Verapamil is acidic and will cause uncomfortable feeling, thus needs to be diluted before injecting
• Heparin dose can be adjusted depending on the purpose of the angiography

Avoiding Complications

• Before the procedure, review the CTA of the neck to determine whether the patient has an aberrant right subclavian artery.
• When injecting the anesthetics, make sure all the air in the syringe is purged out, as subcutaneous air could severely interfere with the ultrasound imaging and obscure the artery.
• When injecting a spasmolytic cocktail into an awake patient, make sure to inform the patient and hold the patient's arm in place to prevent sudden movement of the arm due to discomfort.

Cases

1

Ultrasound-Guided Radial Artery Puncture

A: Frequently, there is an accompanying vein (red arrow) running alongside the radial artery (yellow arrowhead).
B: Applying gentle pressure on the wrist will cause the vein to collapse, while the artery remains full with pulsations. Observe the slight "upward shift" of both the collapsed vein and the artery (closer to the skin).

2

The local anesthetic infiltrated area (white diamond) can be seen above the right radial artery (red star).

• (A): Pre-injection.
• (B): Post-injection.

3

This angiography revealed a tortuous right radial artery origin with adjacent two U-turns. The Glidewire was too stiff to safely navigate through these two turns (red arrow). Consequently, the decision was made to abandon radial access and switch to a femoral access. In cases where the right radial artery remains the only viable option for access, one could consider using a microwire to guide the selection of the brachial artery, followed by a microcatheter to straighten the radial artery origin.

• Orange arrow: The tip of the sheath.
• White arrow: Radial artery.
• Blue arrow: Ulnar artery.
• Green arrow: Brachial artery.

4

The right VA (pink arrow) is typically the first artery to catheterize in diagnostic cerebral angiography via the radial access.

(A): In this pre-operative CTA neck 3D reconstruction view, the right VA origin (green arrow) can be clearly recognized with its relative location to the tip of the distal right subclavian curve (white arrow).
(B): Advance the catheter tip (orange arrow) to the estimated VA origin and obtain a roadmap to assist in artery catheterization.

An alternative method to localize the right VA origin would be to advance the catheter tip more distally and then retract it while puffing contrast to opacify it.