Entry sites for coronary angiography and therapeutic interventions: from the proximal to the distal radial artery.

When coronary angiography was introduced at the Montreal Heart Institute, Montreal, Quebec, in 1964, a cutdown arteriotomy of the proximal radial artery 2 to 3 cm distal to its origin was selected as the standard access site used instead of the brachial artery approach described by Mason Sones Jr. The risk of symptomatic local thrombosis requiring surgical care appeared less at that site on the basis of collateral circulation to the hand by the ulnar and palmar arches. Attempts to replace the time-consuming cutdown arteriotomy by a percutaneous transarterial approach led successively to the axillary, femoral and brachial arteries and finally, over 20 years later, to the radial artery. The transradial approach for diagnostic angiography, first reported in 1989 and adapted by others several years later for angioplasty, is now used in over 44 countries. The only contraindication for this approach is the rare, inadequate ulnar artery collateral circulation to the hand, clinically recognized by an abnormal Allen test. The transradial approach is advantageous in that there is an easier and safer postprocedural hemostasis at the entry site, it is preferred by patients and ambulation within hours is compatible with an outpatient procedure.