Catheter technic in vertebral arteriography.

Abstract

Selective catheterization of the vertebral artery represents an easy and safe approach to vertebral arteriography. Although this technic has been previously described (2–4, 6, 8), it has not been widely used. For the past two years selective vertebral artery catheterization has been employed at the University of California Hospitals, San Francisco, and in the following report our experience with this technic is reviewed. Technic The vertebral artery may be catheterized from either the axillary or the femoral artery. In elderly patients, transfemoral vertebral catheterization may be difficult because of tortuosity and elongation of the aorta and of the brachiocephalic vessels. Inthese instances thetransaxillaryapproach has proved useful (5, 12). In patients younger than fifty-five years, the vertebral artery is usually easily catheterized by way of the femoral artery. Usually, a local anesthetic is employed for the examination, a general anesthetic being administered only to young children or unco-operative adults. Adults in a fasting state are given Benadryl 0.05 g and Nembutal 0.05 g before being brought to the radiology department. Atropine sulfate 0.0006 g is injected intramuscularlyimmediately preceding the study. For local anesthesia, Xylocaine 1 per cent is used. Cannulization of the femoral artery is accomplished with an 18-gauge thinwalled needle (inner diameter 0.965 mm, outer diameter 1.27 mm). A slightly opaque polyethylene catheter3 (1. D., 0.045 in., O.D., 0.065 in.) is then introduced into the femoral artery, using the Seldinger technic. In adults a catheterwith a slightly curved tip is used. This allows the operator to change the position of the tip by rotating the catheter and facilitates catheter entry into the subclavian and vertebral arteries (Fig. 1). A straight catheter is used in children, since the left vertebral artery usually forms a direct line with the proximal left subclavian artery and the aorta (Fig. 2). In infants, the femoral artery is punctured with a 19-gauge thinwalled needle (1. D., 0.711 mm, O. D., 1.09 mm) and a smaller polyethylene catheter4 (1. D., 0.037 in., O. D., 0.054 in.) is introduced. After its advancement into the lower thoracic aorta, the cathether is filled with contrast medium to enhance its visualization. It is then slowly advanced until its tip is thought to be at the orifice of the vertebral artery. The location of the catheter is then verified by a small injection of contrast material. As soon as the catheter has entered the vertebral artery, 1 to 2 m1 of medium is injected and the rate of flow observed. If the passage of contrast agent is delayed, the catheter is withdrawn immediately and placement of its tip in the contralateral vertebral artery is attempted. When the vertebral blood flow is satisfactory, as observed by rapidity of washout of contrast medium, the catheter is advanced gently into the vertebral artery for 2 to 4 cm, about to the level of the fourth cervical vertebra.