Patent ID: 8348987

Claim:
A balloon catheter for dilation of a vessel wall, comprising: a balloon having a distal portion, and a proximal portion, and a working region disposed therebetween, said working region being sized to dilate a vessel wall; a catheter having a distal end and a proximal end, said balloon being mounted on a distal portion of said catheter, wherein said catheter further comprises an inflation lumen extending therethrough in fluid communication with an interior region of said balloon, said balloon being expandable between a deflated configuration having a first diameter in which said balloon is folded and an inflated configuration having a second diameter in which said balloon is unfolded, said second diameter being greater than said first diameter; a circumferentially and longitudinally continuous metallic scoring structure having a diameter in an initial unrestrained relaxed state that is smaller than said first diameter of said balloon, wherein said scoring structure is disposed around an outer surface of said balloon in an expanded state, said scoring structure thereby continually exerting a radially inward compressive force against said balloon, such that when said balloon is expanded and contracted between said deflated configuration at said first diameter and said inflated configuration at said second diameter, said scoring structure expands and contracts in a radial direction and remains in continuous compressive contact with at least a radially outermost portion of said balloon as said balloon is inflated and deflated, said scoring structure returning toward its initial unrestrained relaxed state upon deflation of said balloon, said scoring structure thereby not being capable of being implanted to support said vessel wall; wherein said scoring structure is entirely free of attachment to said balloon and said catheter, said scoring structure comprising a plurality of structural members having an atraumatic radially inner surface in compressive contact with said balloon, and a radially outer surface shaped to engage and score a vessel wall when said balloon is expanded to said inflated configuration, said structural members of said scoring structure being connected in an undulating pattern forming a plurality of ring structures, each of said ring structures having a substantially cylindrical shape, and a plurality of longitudinal members extending between and connecting each of said ring structures in a continuous uninterrupted manner.