Apparatus and methods for selectively stenting a portion of a vessel wall

Abstract

Methods and apparatus for treating vascular abnormalities in highly tortuous vessels are provided comprising a stent having at least one end region that engages a first portion of a circumference of a vessel in a region adjacent to an abnormality to anchor the stent, and a mid-region that engages a second portion of the circumference of the vessel wall to span the abnormality, the second portion having a smaller circumferential extent than the first portion. The mid-region includes a plurality of members that span the abnormality and form a lattice that occludes the abnormality. A delivery system also is provided to deliver the stent within a parent artery and orient the mid-region of the stent to span the abnormality.

What is claimed is:  
     
         1 . Apparatus for treating an abnormality in a vessel, the apparatus comprising: 
 a tubular member configured to circumferentially engage a first portion of a circumference of the vessel adjacent to the abnormality; and    a mid-region coupled to the tubular member, the mid-region comprising a plurality of members having a convex outer surface that engages a second portion of the circumference of the vessel, the second portion smaller than the first portion, the plurality of members spanning the abnormality.    
     
     
         2 . The apparatus of    claim 1    wherein the tubular member and the mid-region comprise arcuate portions interconnected by a plurality of bends or cusps.  
     
     
         3 . The apparatus of    claim 1    wherein the tubular member has a longitudinal axis, the plurality of members oriented generally perpendicular to the longitudinal axis.  
     
     
         4 . The apparatus of    claim 1    wherein the tubular member comprises a coiled sheet.  
     
     
         5 . The apparatus of    claim 4    wherein the coiled sheet and mid-region comprises a plurality of openings.  
     
     
         6 . The apparatus of    claim 1    wherein the first portion is substantially equal to the full circumference of the vessel.  
     
     
         7 . The apparatus of    claim 1    wherein the first portion is less than the full circumference of the vessel.  
     
     
         8 . The apparatus of    claim 1    wherein the plurality of members engage one-half of the circumference of the vessel.  
     
     
         9 . The apparatus of    claim 1    wherein the tubular member and mid-region further comprise a shape memory metal alloy or biocompatible polymer.  
     
     
         10 . The apparatus of    claim 1    further comprising a graft material covering the mid-region.  
     
     
         11 . The apparatus of    claim 1    further comprising a delivery system comprising a first catheter having a distal end adapted to receive the tubular member and mid-region, the first catheter having a lumen and a first gear disposed within the lumen for orienting the mid-region so that it spans the abnormality.  
     
     
         12 . The apparatus of    claim 11   , wherein the first gear comprises a lumen that permits a guide wire to extend beyond the distal end of the first catheter into the vessel.  
     
     
         13 . The apparatus of    claim 11    further comprising a second catheter configured for insertion into the lumen of the first catheter, the second catheter having a distal end and a second gear disposed on the distal end, the second gear configured to engage the first gear when the second catheter is inserted in the lumen.  
     
     
         14 . The apparatus of    claim 13   , wherein: 
 the second gear comprises a guide wire tip; and    the first gear comprises a lumen that permits the guide wire tip to extend beyond the distal end of the first catheter into the vessel.    
     
     
         15 . Apparatus for deploying a prosthesis to treat a region of a vessel, the prosthesis having a feature that is aligned with the region, the apparatus comprising: 
 a flexible catheter having a distal end adapted to receive the prosthesis, a lumen and a first gear disposed within the lumen, the first gear rotating the flexible catheter to orient the feature so that it is aligned with the region.    
     
     
         16 . The apparatus of    claim 15    further comprising a torsion catheter configured for insertion into the lumen of the flexible catheter, the torsion catheter having a distal end and a second gear disposed on the distal end, the second gear configured to engage the first gear when the torsion catheter is inserted in the lumen.  
     
     
         17 . The apparatus of    claim 15   , wherein the first gear comprises a lumen that permits a guide wire to extend beyond the distal end of the flexible catheter into the vessel.  
     
     
         18 . The apparatus of    claim 16   , wherein: 
 the second gear comprises a guide wire tip; and    the first gear comprises a lumen that permits the guide wire tip to extend beyond the distal end of the first catheter into the vessel.    
     
     
         19 . The apparatus of    claim 15    wherein: 
 the first gear comprises a cylindrical portion and a stepped portion having an engagement surface; and  
 the second gear comprises a cylindrical portion and a stepped portion having an engagement surface that mates with the engagement surface of the first gear.  
 
     
     
         20 . The apparatus of    claim 15    wherein the first gear further comprises a longitudinally-oriented marker band.  
     
     
         21 . The apparatus of    claim 15    wherein the first catheter further comprises an electrical conductor, the apparatus further comprising a controller that supplies radio-frequency power to the second gear via the electrical conductor.  
     
     
         22 . The apparatus of    claim 15    wherein the prosthesis is mounted on the catheter by a thermally activated adhesive or polymer.  
     
     
         23 . The apparatus of    claim 15    wherein the prosthesis is mounted on the catheter by an electrically erodible wire.  
     
     
         24 . The apparatus of    claim 15    wherein a retractable sheath retains the prosthesis on the catheter.  
     
     
         25 . A method of treating an abnormality at a treatment site within a vessel, the method comprising: 
 providing a stent having tubular end region comprising at least one curved section having a convex outer surface that engages a first portion of a circumference of the vessel, and a mid-region comprising a plurality of members having a convex outer surface that engages a second portion of a circumference of the vessel, the second portion smaller than the first portion; and    transluminally disposing the stent at the treatment site; and    aligning the mid-region of the stent so that the plurality of members span the abnormality.    
     
     
         26 . The method of    claim 25   , further comprising: 
 providing a delivery system for deploying the stent, the delivery system comprising a first catheter having a distal end configured to receive the stent, a lumen, and a first gear disposed within the lumen,    wherein aligning the mid-region of the stent so that the plurality of members span the abnormality comprises operating the first gear to rotate the distal end of the first catheter.    
     
     
         27 . The method of    claim 26   , wherein providing a delivery system for deploying the stent further comprises providing a second catheter having a proximal end, a distal end and a second gear disposed on the distal end, the method further comprising: 
 inserting the second catheter into the lumen of the first catheter; and    engaging the second gear with the first gear,    wherein operating the first gear to rotate the distal end of the first catheter comprises rotating a proximal end of the second catheter.    
     
     
         28 . The method of    claim 27    further comprising: 
 providing a controller that outputs a radio-frequency power; and  
 coupling the controller to the second catheter to release the stent from the distal end of the first catheter.  
 
     
     
         29 . The method of    claim 26    wherein a thermally activated adhesive or polymer retains the stent on the first catheter, and the method further comprises selectively resistively heating a portion of the first catheter to melt the adhesive or polymer to release the stent from the first catheter.  
     
     
         30 . The method of    claim 26    wherein an electrically erodible wire retains the stent on the first catheter, and the method further comprises delivering electrical power to the electrically erodible wire to release the stent from the first catheter.  
     
     
         31 . The method of    claim 26    wherein a retractable sheath retains the stent on the first catheter, and the method further comprises retracting the sheath to release the stent from the first catheter.