Establishing vascular access is essential in interventional Cardiology. In general the ideal access route should be safe and stable and puncture should be possible in a minimum of time and with a minimum of effort while providing a high success rate.
Common contemporary access sites for coronary angiography and Intervention are: - radial - femoral - brachial - ulnar
Classically vascular access is secured and maintained by implantation of an access sheath. Depending on the vessel, different types and sizes of sheaths are available. Usually via side access injection of medication can be performed through the sheath or blood drawn from the vessel. Sheaths are characterized by inner and outer diameter ("french"), length of the tube and sometimes additional features (Special tapering, stiffness, ect). Note: in case of transradial approach the practice of sheath-less catheterization should be mentioned (link).
RADIAL: Most commonly a 5 French system is used. Because of the smaller Diameter of the radial artery, the sheath sets usually provide an extra floppy, fine guidewire for the Seldinger maneuver and the introducer has extra tapering. Of note: typically after Implantation of the radial sheaths administration of spasmolytic medications such as nitroglycerine and verapamile will performed to avoid spasm.