Collapsible and self-expanding cannula for a percutaneous heart pump and method of manufacturing

Abstract

An expandable cannula for a percutaneous heart pump includes a substantially open proximal end and a substantially open distal end. The expandable cannula includes an elongate central portion disposed between the proximal end and the distal end, the elongate central portion having an inner surface and an opposing outer surface. A first fluid impermeable film is disposed on at least one of the inner surface and the outer surface. The first fluid impermeable film comprises a polymer and has a thickness within a range of from 10 μm to 200 μm.

What is claimed is: 
     
         1 . An expandable cannula for a percutaneous heart pump, the expandable cannula comprising:
 a substantially open proximal end;   a substantially open distal end; and   an elongate central portion disposed between the proximal end and the distal end, the elongate central portion having an inner surface and an opposing outer surface;   a first fluid impermeable film disposed on at least one of the inner surface and the outer surface, the first fluid impermeable film comprising a polymer and having a thickness within a range of from 10 μm to 200 μm.   
     
     
         2 . The expandable cannula according to  claim 1 , wherein the first fluid impermeable film is disposed on the first surface and a second fluid impermeable film is disposed on the second surface. 
     
     
         3 . The expandable cannula according to  claim 2 , wherein the second fluid impermeable film comprises a polymer and has a thickness within a range of from 10 to 200 μm. 
     
     
         4 . The expandable cannula according to  claim 1 , wherein the elongate central portion of the cannula comprises a shape memory alloy. 
     
     
         5 . The expandable cannula according to  claim 1 , wherein the first fluid impermeable film is a laminate comprising at least two layers. 
     
     
         6 . The expandable cannula according to  claim 1 , wherein the first fluid impermeable layer is thermally bonded to the elongate central portion. 
     
     
         7 . The expandable cannula according to  claim 1 , wherein the elongate central portion comprises a mesh structure. 
     
     
         8 . The expandable cannula according to  claim 7 , wherein the first fluid impermeable film is disposed on the first surface and a second fluid impermeable film is disposed on the second surface, and the first fluid impermeable film is bonded to the second fluid impermeable film via bond structures extending through the mesh structure. 
     
     
         9 . The expandable cannula according to  claim 8 , wherein the first fluid impermeable film and the second impermeable film are thermally bonded to one another. 
     
     
         10 . The expandable cannula according to  claim 8 , wherein a total wall thickness of the first fluid impermeable film, the elongate central portion and the second fluid impermeable film together is from 70 μm to 550 μm. 
     
     
         11 . The expandable cannula according to  claim 8 , wherein each of the first fluid impermeable film and the second fluid impermeable film comprise a plurality of layers. 
     
     
         12 . The expandable cannula according to  claim 8 , wherein at least one of the first fluid impermeable film and the second fluid impermeable film comprises a biocompatible polymer. 
     
     
         13 . The collapsible cannula according to  claim 1 , wherein the thermal transition temperature of the polymer is from 50° C. to 250° C. 
     
     
         14 . The collapsible cannula according to  claim 13 , wherein the thermal transition temperature is from 100° C. to 250° C. 
     
     
         15 . The expandable cannula according to  claim 1 , wherein the elongate central portion comprises a nickel-titanium alloy. 
     
     
         16 . The expandable cannula according to  claim 1 , wherein the polymer is a thermoplastic elastomer. 
     
     
         17 . The expandable cannula according to  claim 16 , wherein the thermoplastic elastomer is selected from the group consisting of a thermoplastic, segmented polyurethane block copolymer, a poly(ether-b-amide) copolymer, poly(ether ester) block copolymer, a functionalized olefinic thermoplastic elastomer having polar functional groups, a styrenic thermoplastic elastomer functionalized by polar functional groups, and combinations thereof, wherein the polar functional groups are selected from the group consisting of maleic anhydride, acrylate, epoxy, amine, and combinations thereof. 
     
     
         18 . The expandable cannula according to  claim 1 , wherein the first fluid impermeable film is disposed on the first surface and a second fluid impermeable film is disposed on the second surface and wherein the first fluid impermeable film, the second fluid impermeable film, and the elongated central portion are a fused integrated structure having a substantially smooth, continuous inner surface and a substantially smooth, continuous outer surface. 
     
     
         19 . The collapsible and self-expanding cannula according to  claim 18 , wherein a surface layer of the first fluid impermeable film comprises a first biocompatible thermoplastic elastomer, and a surface layer of the second fluid impermeable film comprises a second biocompatible thermoplastic elastomer. 
     
     
         20 . The collapsible and self-expanding cannula according to  claim 19 , wherein the first biocompatible thermoplastic elastomer and the second biocompatible thermoplastic elastomer, are independently selected from the group consisting of a thermoplastic polyurethane block copolymers comprising hard blocks and soft blocks of different types, and
 wherein the hard blocks and the soft blocks are selected from the group consisting of poly(ether urethane), poly(carbonate urethane), poly(ester urethane), silicone-poly(ether urethane), silicone-poly(carbonate urethane), and a blend or admixture of a combination thereof.