| abstract |
An infusion catheter, for use in conjunction with a balloon dilatation catheter, comprises an elongate, flexible tube defining an infusion lumen, and an expansible infusion sleeve located near its distal end, the sleeve comprising an expansible network of spacer elements disposed between proximal and distal elastomeric sealing bands. When deployed at a treatment site in a blood vessel or other bodily passage, the elongate tube of the present invention concentrically surrounds the dilatation catheter, the infusion lumen being defined therebetween, with the infusion sleeve concentrically surrounding the balloon. The spacer elements of the expansible network create an axially-elongated, circumferential flow path or interstice between the balloon and the vessel wall when the balloon is inflated, the interstice being in fluid communication with the infusion lumen, through which a therapeutic fluid is delivered to the treatment site. In a first preferred embodiment, the infusion sleeve comprises a network of filaments that define the spacer elements, wherein the network has a substantial degree of shape memory, allowing the sleeve to return to its original shape when the balloon is deflated. The grid is permanently fixed to the proximal and distal sealing bands. In a second preferred embodiment, the sleeve comprises a perforated tube of deformable, biocompatible metal formed as a mesh or latticework that defines a network of spacer elements. The perforated tube is detachably joined to the sealing bands, so that it may be left in place as a stent after the catheter is withdrawn. |