Patent ID: 6183443
Filing Date: 2001-02-06
Classification: A61B,A61M

Abstract:
A sheath system for introducing intravascular devices percutaneously, the sheath system comprising:a first elongate flexible tubular sheath for placement within a vessel to slidably receive intravascular devices, the first sheath including a wall having a continuous outer surface, the outer surface defining an outer diameter;a second elongate flexible tubular sheath for placement within a vessel to slidably receive intravascular devices comprising a polymer material, the second sheath being coaxially slidable over the first sheath and being capable of percutaneously entering the vessel by distal advancement of the second sheath over the first sheath, the second sheath comprising a wall having a continuous outer surface and defining a first inner diameter at least equal to the outer diameter of the first sheath, the second sheath wall being selectively permanently expandable while within the vessel to define a second, larger inner diameter and maintaining a substantially uniform tubular shape without an additional member extending through the second sheath, wherein the polymer material is a shape-memory polymer having a glass transition temperature greater than the normal temperature of the human body so that the second sheath is capable of being forcibly expanded to define the second larger diameter and maintain the second diameter after the polymer has cooled to a temperature less than the glass transition temperature; andan elongate mandrel having an outer diameter greater than the inner diameter of the of the second sheath, and having a heated proximal end, such that as the heated proximal end of the mandrel is forcibly inserted into the second sheath, the shape memory polymer is heated beyond the glass transition temperature and expands to define the second, larger diameter.