Radial Access for Neurovascular Procedures

Abstract

Radial access is increasingly being considered in neurovascular procedures after becoming the standard access route in percutaneous cardiovascular interventions. Current barriers include a lack of dedicated equipment for radial to neurovascular target vessels, lack of training for physicians and fellows, and physician bias toward femoral access secondary to greater experience and familiarity. Radial access has been proven to be safer and the preferred access route by most patients. These two factors make radial access inevitability when the aforementioned barriers are overcome. The purpose of this brief article is to highlight some important considerations of radial access specific to the neurovasculature.

Keywords: cerebral angiography; complications; interventional radiology; radial access.

Fig. 1

Subjective patient responses and preferences for radial versus femoral access.

Fig. 2

( a ) A schematic representation of the Elevate Armboard (Model 8100) with proprietary integrating single-use mBrace 4250 wrist support (Advanced Vascular Dynamics, Milwaukie, OR). ( b ) Elevate Armboard with disposable towel secured to foam arm splint as wrist support. This figure also depicts the basic arm positioning with the use of a disposable towel and foam arm splint that is routinely used in our laboratory. Of note, positioning the arm board as low toward the bottom of the table and as tight to the table as possible allows for a lateral fluoroscopy tube to be brought as close to the patient's shoulder as possible. For standard radial or ulnar access, the wrist can be slightly extended and secured to the foam board. In patients with distal radial access, the hand and arm can be kept in a more anatomic position to facilitate access and maximize patient comfort.

Fig. 3

( a ) Transverse duplex ultrasound image of distal radial artery (yellow circle) with overlying subcutaneous mixture of lidocaine and nitroglycerin (blue border). ( b ) Ultrasound probe at 45 degrees for initial skin entry which is fanned to 90 degrees (arrow) as needle is advanced to the border of the radial artery. ( c ) Indentation of the radial artery lumen (arrow) prior to single-wall puncture for access.

Fig. 4

( a ) Most common upper extremity arterial anatomy with radial, interosseus, and ulnar arteries. ( b ) Variant radial artery loop near the antecubital fossa (arrow). ( c ) High origin of the radial artery from the axillary artery (arrow) with radial artery loop in the upper arm.

Fig. 5

A 6-Fr radial access example for neurovascular intervention. This example is for a triaxial approach used for delivery of a pipeline flow diverting stent (Medtronic, Minneapolis, MN); however, a coaxial approach using just a neuro guide catheter (0.070–0.071) system can be used for two microcatheters in stent-assisted coiling or balloon-assisted coiling.

Fig. 6

( a ) A 5-Fr diagnostic catheter (arrow) is used to select the high cervical/horizontal petrous right internal carotid artery and a 260-cm wire is used for subsequent exchange. ( b ) After exchanging the short radial sheath for direct access with a neuro guide catheter (0.088–0.091 in inner diameter), the guide is advanced to the proximal right subclavian artery with the provided obturator (arrow). ( c ) Once the turn is made from the subclavian artery into the cervical ICA, the obturator is exchanged for an intermediate catheter (aspiration catheter).

Fig. 7

Typical stroke intervention setup. (1) Direct radial access with neuro sheath (0.088–0.091 in), (2) aspiration catheter, (3) stent retriever, (4a) line for continuous pump aspiration during stent/aspiration catheter withdrawal, (4b) syringe aspiration for guide during stent/aspiration catheter withdrawal.