ABSTRACT
The basic sheath provides access for medication and contrast, is advanced over a guidewire, may or may not have a radiopaque tip, secures the access site, prevents bleeding during the procedure, and is an access point where diagnostic or therapeutic catheters can be introduced into the vascular system. The guidewire must be inserted into the vessel for a sufficient distance that the anchoring is secure in the vascular system for sheath advancement, and a more firm or sturdy portion of the wire is available at the skin level over which to advance the sheath. The sheath is loaded onto the guidewire by an assistant and advanced all the way to the entry site. A dilator may then be advanced to secure the entry site and slightly dilate the tract. Sizing issues are confusing but they should be considered prior to the case. Fluoroscopy is occasionally useful in planning the puncture.
