Angioplasty balloon with thin-walled taper and method of making the same

Abstract

An angioplasty balloon and method of manufacture are provided. The balloon has a working length and a taper each having a substantially equivalent thickness. This allows the balloon to be steered easily through vasculature to the site of a stenosis prior to inflation during an angioplasty procedure. The taper thickness in particular is achieved through use of a specially designed multi-tubular slug which is molded to form the angioplasty balloon of the present invention.

1 . A slug for manufacturing an angioplasty balloon, said slug comprising: 
 a shortened outer tube and: 
 an inner tube, said inner tube being longer in length than said shortened outer tube, said shortened outer tube circumferentially surrounding said inner tube.  
   
     
     
         2 . The slug of  claim 1  wherein said shortened outer tube is fused to said inner tube.  
     
     
         3 . The slug of  claim 1  wherein said outer tube has an outer tube wall thickness greater than an inner tube wall thickness of said inner tube.  
     
     
         4 . The slug of  claim 1  wherein said shortened outer tube has a constant outer tube inner diameter cooperating with a constant inner tube outer diameter.  
     
     
         5 . The slug of  claim 1  wherein said shortened outer tube has a variable outer tube inner diameter cooperating with a variable inner tube outer diameter.  
     
     
         6 . The slug of  claim 1  wherein said shortened outer tube has an end, said end being pre-necked.  
     
     
         7 . The slug of  claim 1  wherein said slug is comprised of a polymeric material selected from the group consisting of: polyethylene terephthalate, a polyetherblockamide, a polyamide, a thermoplastic copolyester, a polyolefin, and a polyether-ester block copolymer.  
     
     
         8 . The slug of  claim 1  wherein one of said shortened outer tube and said inner tube is comprised of tubing material, said tubing material being a co-extruded polymer of two or more layers.  
     
     
         9 . The slug of  claim 1  wherein said slug further comprises an additional tube, said additional tube circumferentially surrounding said inner tube.  
     
     
         10 . A method of forming an angioplasty balloon catheter from a slug, said method comprising: 
 surrounding an inner tube with a shortened outer tube to form said slug;    placing said slug within a mold, said mold defining a desired angioplasty balloon profile; and    molding said slug with said mold to form an angioplasty balloon catheter having a working length extending into a taper which further extends into a shaft.    
     
     
         11 . The method of  claim 10  further comprising extruding said inner tube and said shortened outer tube in a manner giving randomized molecular alignment to any polymer comprising said inner tube and said shortened outer tube prior to said surrounding.  
     
     
         12 . The method of  claim 10  further comprising pre-necking an outer end of said shortened outer tube prior to said molding.  
     
     
         13 . The method of  claim 10  further comprising adding an additional tube circumferentially around said inner tube prior to said molding.  
     
     
         14 . The method of  claim 10  wherein said molding further comprises: 
 heating said slug; and  
 pressurizing said slug to form an angioplasty balloon within said mold, said angioplasty balloon comprising said working length and said taper.  
 
     
     
         15 . The method of  claim 14  wherein said heating further comprises providing a temperature above a glass transition temperature of any polymer comprising said slug.  
     
     
         16 . The method of  claim 14  wherein said pressurizing further comprises providing a pressure of at least 300 p.s.i. within said mold.  
     
     
         17 . The method of  claim 10  further comprising fusing said shortened outer tube to said inner tube prior to said molding.  
     
     
         18 . The method of  claim 17  wherein said fusing comprises heating said slug above a glass transition temperature of any polymer comprising said slug.  
     
     
         19 . The method of  claim 10  wherein said working length has a working length thickness, said taper has a taper thickness, and said shaft has a shaft thickness, said working length thickness, said taper thickness, and said shaft thickness being substantially equivalent.  
     
     
         20 . The method of  claim 10  wherein said shortened outer tube further comprises an outer end, said molding transforming said shortened outer tube into said working length and said molding creating said taper from said outer end and said inner tube.  
     
     
         21 . An angioplasty balloon comprising: 
 a working length having a working length wall thickness; and    a taper extending from said working length and having a taper wall thickness, said taper wall thickness and said working length wall thickness being substantially equivalent.    
     
     
         22 . The angioplasty balloon of  claim 21  further comprising a shaft extending from said taper and having a shaft wall thickness, said shaft wall thickness being substantially equivalent to said taper wall thickness and said working length wall thickness.  
     
     
         23 . The angioplasty balloon catheter of  claim 22  wherein said working length further comprises an inner diameter being substantially constant throughout said working length, said shaft further comprises an inner shaft diameter being substantially constant throughout said shaft, and said taper further comprises an inner taper diameter which diminishes throughout said taper from said working length to said shaft, providing a smooth transition there between.  
     
     
         24 . The angioplasty balloon of  claim 1  further comprising a two-layer composite capable of withstanding pressures higher than conventionally possible, said two-layer composite comprising said working length.  
     
     
         25 . The angioplasty balloon of  claim 24  wherein said two-layer composite further comprises at least a portion of said taper.  
     
     
         26 . The angioplasty balloon of  claim 24  or  claim 25  wherein said two-layer composite is a polyetherblockamide-polyamide composite.  
     
     
         27 . The angioplasty balloon of  claim 22  wherein said shaft is comprised of a polyamide.  
     
     
         28 . The angioplasty balloon of  claim 21  wherein said taper and said working length comprise an angioplasty balloon, said angioplasty balloon being between 10 mm and 40 mm in length.  
     
     
         29 . The angioplasty balloon of  claim 22  wherein said working length wall thickness, said taper wall thickness, and said shaft wall thickness are between 0.010 mm and 0.051 mm.  
     
     
         30 . The angioplasty balloon of  claim 22  wherein said working length further comprises an outer diameter, said shaft further comprises an outer shaft diameter, and said taper further comprises an outer taper diameter, said outer diameter, said outer shaft diameter, and said outer taper diameter being between 0.60 mm and 15.0 mm.