RADIOPAQUE NON-KINKING THIN-WALLED INTRODUCER SHEATH

摘要

A sheath is described that is non-kinking and with a thinner wall as compared with sheaths that are currently available. To achieve both a thinner wall for the sheath and to avoid kinking, this invention uses a helical metal coil for its interior which is fabricated from flat wire. To provide the thinnest wall sheath which is not readily crushed in normal handling, a wire thickness between 0.00075 and 0.0035 inches can be used with a ratio of wire width to wire thickness that lies between 3 and 80 depending on the wire thickness. A thin plastic covering is coated onto and between the turns of the metal coil or the covering might be attached using heat shrinkable tubing, or by molding or extruding plastic over the thin helical metal coil. A separate plastic cylinder can be placed inside the coils and also plastic can be placed in the space between adjacent turns of the flat wire. At the proximal end of the sheath is an adapter(hemostasis valve) through which the catheters can be placed. This adapter wouldtypically be molded from a plastic so as to both join onto the metal coil as well as mold onto the plastic covering of the metal coil. At its distal end, the sheath wouldadvantageously combine a metal portion for radiopacity and at its extreme end a soft plastic tapered end piece.