Apparatus and methods for dilating vessels and hollow-body organs

A kit for dilating a vessel or organ comprising:

• a catheter comprising a shaft having proximal and distal ends and a balloon disposed on the distal end of the shaft;
• and
• a sheath selected from among a plurality of sheaths, each one of the plurality of sheaths including a mesh portion having a predetermined expanded diameter, each one of the sheaths comprising:
• a tubular member having proximal and distal ends, the tubular member disposed surrounding the shaft;
• a mesh portion attached to the distal end of the tubular member and disposed surrounding the balloon for sliding movement relative thereto, the mesh portion comprising a non-compliant material having a first state wherein the mesh portion has a first length and an insertion diameter and a second state wherein the mesh portion has second length, shorter than the first length, and a predetermined expanded diameter;
• and
• a retractor element disposed on the proximal end of the tubular member for retracting the mesh portion to the first state,
• wherein, when the balloon is fully inflated, the mesh portion of the selected one of the plurality of sheaths is in the second state and attains the predetermined expanded diameter, the mesh portion constraining the balloon from further expansion.

A method of dilating a constriction in a vessel or organ, the method comprising steps of:

• providing apparatus comprising a catheter a distal end and a balloon disposed on the distal end and a sheath disposed on the catheter, the sheath including a mesh portion aligned with and surrounding the balloon, the mesh portion arranged for sliding movement relative to the balloon, the mesh portion comprising a non-compliant material having a first state wherein the mesh portion has a first length and an insertion diameter and a second state wherein the mesh portion has second length, shorter than the first length, and a selected predetermined expanded diameter;
• pulling the sheath in a proximal direction so that the mesh portion assumes the first state;
• inserting a guidewire into the vessel or organ;
• advancing the apparatus along the guidewire to position the mesh portion and balloon within the constriction;
• and
• inflating the balloon so that the mesh portion expands to the second state and attains the selected predetermined diameter to disrupt the constriction, the mesh portion constraining the balloon from further expansion.