Modular endluminal stent-grafts and methods for their use

Abstract

Modular endoluminal stent-grafts include at least two different sized stent-grafts which are deployed one within the other. According to one embodiment of the invention, a first stent-graft is provided having a flared end which is expandable to a first diameter and a midsection which is expandable to a second diameter smaller than the first diameter. A second stent-graft is also provided having an end which is expandable to a diameter which engages the midsection of the first stent-graft. The first embodiment of the invention is deployed by expanding the first stent-graft such that its flared end engages a large diameter vessel, then expanding the second stent-graft inside the midsection of the first stent graft and inside a small diameter vessel such that the second stent graft engages the small diameter vessel and the midsection of the first stent-graft. According to a second embodiment of the invention, the midsection of the first stent-graft is reinforced with a flexible member to restrict the midsection from ballooning. According to other aspects of the invention, the first stent-graft is provided with two flared ends and the second stent graft is provided with or without flared ends. According to still another embodiment of the invention, three or more stent-grafts of different expanded diameter are deployed one within the other.

1 . A modular endoluminal stent-graft system for bridging a lesion in a blood vessel having a first large diameter on one side of the lesion and a second small diameter on the other side of the lesion, said system comprising: 
 a) a first stent-graft having a first end, a second end, and a midsection, said first end of said first stent-graft having an expanded diameter equal to or slightly larger than the first large diameter of the blood vessel, said midsection of said first stent-graft having an expanded diameter which is smaller than said expanded diameter of said first end of said first stent-graft;    b) a second stent-graft having a first end, a second end, and a midsection, said first end of said second stent-graft having an expanded diameter equal to or slightly larger than said expanded diameter of said midsection of said first stent-graft and said second end of said second stent-graft having an expanded diameter which is equal to or slightly larger than the second small diameter of the blood vessel, such that 
 in a deployed orientation, said first end of said first stent-graft is adapted to engage the first large diameter of the blood vessel, said first end of said second stent-graft securely engages said midsection of said first stent-graft to hold said second stent graft substantially fixed relative to said first stent-graft, and said second end of said second stent-graft engages the second small diameter of the blood vessel.  
   
     
     
         2 . A system according to  claim 1 , wherein: 
 said first end of said first stent-graft is flared.    
     
     
         3 . A system according to  claim 2 , wherein: 
 said second end of said first stent-graft is flared.    
     
     
         4 . A system according to  claim 1 , wherein: 
 said first end of said second stent-graft is flared.    
     
     
         5 . A system according to  claim 4 , wherein: 
 said second end of said second stent-graft is flared.    
     
     
         6 . A system according to  claim 1 , wherein: 
 at least said midsection of said first stent-graft is reinforced with a flexible material.    
     
     
         7 . A system according to  claim 6 , wherein: 
 said flexible material is selected from the group consisting of polyethylene terphthalate, nylon, polytetrafluoroethylene, polyolefin, polyamide, polycarbonate, polycarbonate urethane, and metallic wire.    
     
     
         8 . A system according to  claim 6 , wherein: 
 said flexible material is selected from the group consisting of sutures, knits, weaves, braids, wires, and stents.    
     
     
         9 . A modular stent-graft system, comprising: 
 a) a first stent-graft having a first end, a second end, and a midsection, said first end of said first stent-graft having an expanded first diameter and said midsection of said first stent-graft having an expanded second diameter which is smaller than said expanded first diameter;    b) a second stent-graft having a first end, a second end, and a midsection, said first end of said second stent-graft having an expanded third diameter equal to or slightly larger than said expanded second diameter of said midsection of said first stent-graft, said second end of said second stent-graft having an expanded fourth diameter equal to or smaller than said third diameter, such that 
 in a deployed orientation, said first end of said second stent-graft securely engages said midsection of said first stent-graft to hold the second stent-graft substantially fixed relative to said first stent-graft.  
   
     
     
         10 . A system according to  claim 9 , wherein: 
 said first end of said first stent-graft is flared.    
     
     
         11 . A system according to  claim 10 , wherein: 
 said second end of said first stent-graft is flared.    
     
     
         12 . A system according to  claim 9 , wherein: 
 said midsection of said first stent-graft is reinforced with a flexible material.    
     
     
         13 . A system according to  claim 12 , wherein: 
 said flexible material is selected from the group consisting of polyethylene terphthalate, nylon, polytetrafluoroethylene, polyolefin, polyamide, polycarbonate, polycarbonate urethane, and metallic wire.    
     
     
         14 . A system according to  claim 12 , wherein: 
 said flexible material is selected from the group consisting of sutures, knits, weaves, braids, wires, and stents.    
     
     
         15 . A system according to  claim 9 , further comprising: 
 c) a third stent-graft having a first end, a second end, and a midsection, said first end of said third stent-graft having an expanded fifth diameter, wherein 
 said midsection of said second stent-graft has an expanded sixth diameter equal to or slightly smaller than said expanded fifth diameter of said first end of said third stent-graft, such that 
 in a deployed orientation, said first end of said third stent-graft engages said midsection of said second stent-graft.  
 
   
     
     
         16 . A system according to  claim 15 , wherein: 
 said first end of said third stent-graft is flared.    
     
     
         17 . A system according to  claim 1 , wherein: 
 said first end of said second stent-graft is coupled to said first stent-graft by one of sutures, wires, adhesive and welds.    
     
     
         18 . A system according to  claim 1 , wherein: 
 said first end of said second stent-graft is coupled to said midsection of said first stent-graft.    
     
     
         19 . A method of bridging a lesion in a blood vessel having a first large diameter on one side of the lesion and a second small diameter on the other side of the lesion, said method comprising: 
 a) obtaining a first stent-graft having a first end, a second end, and a midsection, said first end of said first stent-graft having an expanded diameter equal to or slightly larger than the first large diameter of the blood vessel, said midsection of said first stent-graft having an expanded diameter which is smaller than said expanded diameter of said first end of said first stent-graft;    b) obtaining a second stent-graft having a first end, a second end, and a midsection, said first end of said second stent-graft having an expanded diameter equal to or slightly larger than said expanded diameter of said midsection of said first stent-graft and said second end of said second stent-graft having an expanded diameter which is equal to or slightly larger than the second small diameter of the blood vessel;    c) deploying said first stent-graft by expanding said first stent-graft such that said first end of said first stent-graft engages the first large diameter of the blood vessel; and    d) deploying said second stent-graft by expanding said second stent-graft such that said first end of said second stent-graft engages said midsection of said first stent-graft such that said second stent-graft is substantially fixed relative to said first stent-graft and said second end of said second stent-graft engages the second small diameter of the blood vessel.    
     
     
         20 . A method according to  claim 19 , further comprising: 
 e) obtaining a third stent-graft having a first end, a second end, and a midsection; and    d) deploying said third stent-graft by expanding said third stent-graft such that said first end of said third stent-graft engages said midsection of said second stent-graft.    
     
     
         21 . A modular endoluminal stent-graft system for bridging a lesion in a blood vessel having a first large diameter on one side of the lesion and a second small diameter on the other side of the lesion, said system comprising: 
 a) a first stent-graft having a first end, a second end, and a midsection, said first end of said first stent-graft having an expanded diameter equal to or slightly larger than the first large diameter of the blood vessel, said midsection of said first stent-graft having an expanded diameter which is smaller than said expanded diameter of said first end of said first stent-graft;    b) a second stent-graft having a first end, a second end, and a midsection, said first end of said second stent-graft having an expanded diameter equal to or slightly larger than said expanded diameter of said midsection of said first stent-graft and said second end of said second stent-graft having an expanded diameter which is equal to or slightly larger than the second small diameter of the blood vessel, such that 
 in a deployed orientation, said first end of said first stent-graft is adapted to engage the first large diameter of the blood vessel, said first end of said second stent-graft engages said midsection of said first stent-graft, and said second end of said second stent-graft is adapted to engage the second small diameter of the blood vessel wherein at least said midsection of said first stent-graft is reinforced with a flexible material.  
   
     
     
         22 . A modular stent-graft system, comprising: 
 a) a first stent-graft having a first end, a second end, and a midsection, said first end of said first stent-graft having an expanded first diameter and said midsection of said first stent-graft having an expanded second diameter which is smaller than said expanded first diameter;    b) a second stent-graft having a first end, a second end, and a midsection, said first end of said second stent-graft having an expanded third diameter equal to or slightly larger than said expanded second diameter of said midsection of said first stent-graft, said second end of said second stent-graft having an expanded fourth diameter equal to or smaller than said third diameter, such that 
 in a deployed orientation, said first end of said second stent-graft engages said midsection of said first stent-graft wherein at least said midsection of said first stent-graft is reinforced with a flexible material.  
   
     
     
         23 . A method of bridging a lesion in a blood vessel having a first large diameter on one side of the lesion and a second small diameter on the other side of the lesion, said method comprising: 
 a) obtaining a first stent-graft having a first end, a second end, and a midsection, said first end of said first stent-graft having an expanded diameter equal to or slightly larger than the first large diameter of the blood vessel, said midsection of said first stent-graft having an expanded diameter which is smaller than said expanded diameter of said first end of said first stent-graft wherein at least said midsection of said first stent-graft is reinforced with a flexible material;    b) obtaining a second stent-graft having a first end, a second end, and a midsection, said first end of said second stent-graft having an expanded diameter equal to or slightly larger than said expanded diameter of said midsection of said first stent-graft and said second end of said second stent-graft having an expanded diameter which is equal to or slightly larger than the second small diameter of the blood vessel;    c) deploying said first stent-graft by expanding said first stent-graft such that said first end of said first stent-graft engages the first large diameter of the blood vessel; and    d) deploying said second stent-graft by expanding said second stent-graft such that said first end of said second stent-graft engages said midsection of said first stent-graft and said second end of said second stent-graft engages the second small diameter of the blood vessel.