Methods and apparatus for plaque disruption
Balloon catheters, sleeves, cages, and endoluminal prostheses are provided with stress-applying and spacing features coupled to expandable surfaces thereof. The stress-applying features may have blunt and/or rounded contact regions which contact tissue or calcified regions in the vasculature. The contact regions dent or fracture occlusive material on the wall of a vascular lumen and/or patient valve leaflets when expanded. The spacing features permit blood, drug, and contrast perfusion past structures expanded in the vasculature, particularly balloon catheters.
1 . An apparatus for treating calcification on a wall in a patient's body lumen, the apparatus comprising:
a catheter including a catheter body having a proximal end and a distal segment;
an expandable polymeric balloon disposed at the distal segment of the catheter body, the expandable polymeric balloon having an outer surface configured to be displaced radially outward toward an inner surface of the wall in the patient's body lumen; and
a plurality of plaque-disrupting features distributed over the outer surface of the expandable polymeric balloon, wherein at least some of the plurality of plaque-disrupting features have an upper surface configured to fracture the calcification while reducing damage to the patient's body lumen when the expandable polymeric balloon is expanded within the patient's body lumen;
wherein the at least some of the plurality of plaque-disrupting features comprise discrete bodies;
wherein the at least some of the plaque-disrupting features comprise any one or any combination of a ball, a sphere, a partial sphere, a hemisphere, an ellipsoidal solid, or a dome; and wherein a bottom-most surface of each of the ball, the sphere, the partial sphere, the hemisphere, the ellipsoidal solid, or the dome is directly bonded to the outer surface of the expandable polymeric balloon.
2 . The apparatus as in claim 1 , wherein the at least some of the upper surfaces of the plurality of plaque-disrupting features comprise a convex rounded upper surface.
3 . The apparatus as in claim 2 , wherein the convex rounded upper surface of the at least some of the plurality of plaque-disrupting features has a radial height above the outer surface of the expandable polymeric balloon in a range from a minimum of 0.05 mm, 0.1 mm, 0.15 mm, 0.2 mm, or 0.25 mm to a maximum of 1 mm, 0.5 mm, 0.4 mm, 0.3 mm, or 0.25 mm, and a distribution density in a range from 0.1 to 5 features/mm 2 when the expandable polymeric balloon is expanded.
4 . The apparatus as in claim 2 , wherein the convex rounded upper surface comprises a single convex rounded upper surface.
5 . The apparatus as in claim 1 , wherein the at least some of the plurality of plaque-disrupting features have a lower portion disposed in an indentation on the outer surface of the expandable polymeric balloon.
6 . The apparatus as in claim 1 , wherein the at least some of the plurality of plaque-disrupting features comprise a sphere, partial sphere, or hemisphere.
7 . The apparatus as in claim 1 , wherein the discrete bodies comprise a metal or a metal alloy.
8 . The apparatus as in claim 1 , wherein at least a portion of the plurality of plaque-disrupting features have a footprint with a maximum width, diameter, or other lateral dimension of 4 mm or less.
9 . The apparatus as in claim 1 , wherein the at least some of the plurality of plaque-disrupting features comprise solid metal spheres, partial spheres, or hemispheres with flat or concave bottoms.
10 . The apparatus as in claim 1 , wherein bottoms of the at least some of the plurality of plaque-disrupting features are recessed along the outer surface of the expandable polymeric balloon.
11 . The apparatus as in claim 1 , wherein an encapsulation layer covers an entire working length of the outer surface of the expandable polymeric balloon.
12 . The apparatus as in claim 1 , wherein the at least some of the plurality of plaque-disrupting features are constrained over the outer surface of the expandable polymeric balloon by an elastic sleeve.
13 . The apparatus as in claim 1 , further comprising an encapsulation layer covering the upper surface of the at least some of the plurality of plaque-disrupting features and covering an entire working length of the outer surface of the expandable polymeric balloon.
14 . The apparatus as in claim 1 , wherein the at least some of the plurality of plaque-disrupting features, prior to bonding with the outer surface of the expandable polymeric balloon, are pre-coated with an adhesive, a polymeric material, a hydrophilic material or any combination thereof.
15 . The apparatus as in claim 1 , wherein the plurality of plaque-disrupting features cover a working length of the outer surface of the expandable polymeric balloon.
16 . The apparatus as in claim 1 , wherein the plurality of plaque-disrupting features cover an entire length of the outer surface of the expandable polymeric balloon.
17 . The apparatus as in claim 1 , further comprising an encapsulation layer extending beneath the at least some of the plurality of plaque-disrupting features and covering an entire working length of the outer surface of the expandable polymeric balloon.
18 . The apparatus as in claim 17 , wherein the encapsulation layer comprises at least one of an adhesive, a polymer, or a hydrophilic material.
19 . The apparatus as in claim 17 , wherein the encapsulation layer comprises a polymer selected from the group consisting of thermoplastic fluoropolymers, butyl methacrylates, and thermoplastic polyesters.
20 . The apparatus as in claim 17 , wherein the encapsulation layer is applied over the outer surface of the expandable polymeric balloon and the plurality of plaque-disrupting features by any one of coating, direct fluid application, laminating, or fusing.
21 . The apparatus as in claim 17 , wherein the encapsulation layer has a thickness in a range from 0.01 mm to 0.1 mm.
22 . The apparatus as in claim 17 , wherein the at least some of the plurality of plaque-disrupting features, prior to bonding with the outer surface of the expandable polymeric balloon, are pre-coated with an adhesive, a polymeric material, a hydrophilic material or any combination thereof.
23 . The apparatus of claim 17 , wherein the plurality of plaque-disrupting features are directly bonded to the outer surface of the expandable polymeric balloon through an adhesive, through the encapsulation layer, or both.
24 . The apparatus as in claim 23 , wherein the at least some of the plurality of plaque-disrupting features are immobilized solely by one or more adhesives, the encapsulation layer, or both.
25 . The apparatus as in claim 23 , wherein the encapsulation layer comprises a polymer selected from the group consisting of thermoplastic fluoropolymers, butyl methacrylates, and thermoplastic polyesters.
26 . The apparatus as in claim 23 , wherein the encapsulation layer is applied over the outer surface of the expandable polymeric balloon and the plurality of plaque-disrupting features by any one of coating, direct fluid application, laminating, or fusing.