Patent Publication Number: US-2012041469-A1

Title: Revascularization device with integrated distal emboli protection

Description:
FIELD OF USE 
     This invention is in the field of percutaneous devices that are used to open a vessel of the human body. 
     BACKGROUND OF THE INVENTION 
     In balloon angioplasty or stenting of vessels of the human body, embolic debris can be released and embolize down stream (distally). This can cause damage to tissue distal to the treatment site, including myocardial infarction when coronary arteries are treated, or strokes if carotid arteries are being treated, etc.. Existing distal emboli protection devices such as the Angiogard device of Cordis or RX Accunet of Abbott Laboratories are integrated into a guide wire. This has the disadvantage of having to be delivered to the site of the obstruction before the device being used for revascularization of the vessel is delivered. This mandates one or more extra steps in the procedure to deliver the revascularization device, and requires the use of one or more revascularization devices (extra device). On the other hand, it would be of significant advantage to be able to deliver a revascularization device that has a distal emboli protection capability integrated into the revascularization device itself. 
     SUMMARY OF THE INVENTION 
     The present invention is the incorporation of a distal emboli collection device into the distal section of a percutaneously inserted device for opening an obstruction in a vessel of the human body. Such opening or “revascularization” devices include balloon angioplasty catheters, atherectomy catheters, lasers, and stents. Stents used for recannalization include balloon expandable stents such as the Cordis Cypher and Abbott Xience drug eluting stents and non drug eluting stents such as the Abbott Vision or Medtronic Driver stents and self-expanding stents like the Cordis PRECISE and SMART stents and the Abbott Acculink stent. As self-expanding stents almost always require post implant balloon dilatation, it is envisioned that one embodiment of the present invention would include a self-expanding stent delivery system with an integrated distal emboli protection capability, and an integrated angioplasty balloon for post dilatation, with all three capabilities contained in one device. Although the present invention can be configured as an over the wire or rapid exchange catheter using a standard guidewire, it is also envisioned that to reduce the profile, a fixed wire distal end such as that described by Fischell et al in U.S. Pat. Nos. 6,375,660, 6,936,065 and 7,011,673. 
     Thus it is an object of the present invention to provide the capability for both distal emboli protection and vessel opening in one device. 
     Another object of the present invention to have a balloon angioplasty catheter with an integrated distal emboli protection capability 
     Still another object of the present invention is to have a balloon expandable stent delivery system with integrated distal emboli protection capability. 
     Still another object of the present invention is to have a self-expanding stent delivery system with integrated distal emboli protection capability 
     Yet another object of the present invention is to have a self-expanding stent delivery system with integrated distal emboli protection and a built-in angioplasty balloon. 
     These and other objects and advantages of this invention will become obvious to a person of ordinary skill in this art upon reading of the detailed description of this invention including the associated drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a longitudinal cross section of the distal end of the present invention fixed wire self expanding stent delivery system that includes a balloon to be used for post dilatation of a self expanding stent. 
         FIG. 2A  is an enlargement of the longitudinal cross section of section  2 A of the present invention fixed wire self expanding stent delivery system of  FIG. 1   
         FIG. 2B  is an enlargement of the longitudinal cross section of section  2 B of the present invention fixed wire self expanding stent delivery system of  FIG. 1   
         FIG. 2C  is a longitudinal cross section of the proximal end of the stent delivery system of  FIG. 1 . 
         FIG. 3A  is a longitudinal cross section of the distal section of a stent delivery system with integrated distal protection that is delivered over a guide wire. 
         FIG. 3B  is a longitudinal cross section of the proximal end of an over the wire version of the balloon expandable stent delivery system of  FIG. 3A   
         FIG. 3C  is a longitudinal cross section of the central section of a rapid exchange version of the stent delivery system of  FIG. 3   
         FIG. 4A  is a longitudinal cross section of the fixed wire delivery system of  FIG. 1  after it has been positioned at the site of a stenosis in a vessel of a human body. 
         FIG. 4B  is a longitudinal cross section of the system of  FIG. 1  after the sheath has been pulled back enough to deploy the distal protection subsystem. 
         FIG. 4C  is a longitudinal cross section of the system of  FIG. 1  after the sheath has been pulled back completely and the self expanding stent has been deployed 
         FIG. 4D  is a longitudinal cross section of the system of  FIG. 1  as it would appear during balloon inflation to post dilate the self expanding stent. 
         FIG. 4E  is a longitudinal cross section of the system of  FIG. 1  after the sheath has been advanced until it is ready to collapsed the distal protection sub system. 
         FIG. 4F  is a longitudinal cross section of the system of  FIG. 1  after the distal protection subsystem has been completely collapsed but before the system is withdrawn from the human body. 
         FIG. 4G  is a longitudinal cross section of the vessel of the human body with the post dilated self expanding stent following removal of the stent delivery system. 
         FIG. 5  is a longitudinal cross section of the distal end of the present invention fixed wire balloon angioplasty catheter with integrated distal emboli protection 
         FIG. 6  is a longitudinal cross section of the distal end of the present invention balloon angioplasty catheter with integrated distal emboli protection that is advanced over a guide wire. 
         FIG. 7  is a longitudinal cross section of the distal end of the present invention fixed wire self expanding stent delivery system with integrated distal emboli protection. 
         FIG. 8  is a longitudinal cross section of the distal end of the present invention self expanding stent delivery system with integrated distal emboli protection that is advanced over a guide wire. 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a longitudinal cross section of the distal end of the present invention system  10  for the opening of blocked vessels of the human body that includes both an expandable stent  30  and a balloon  25  to be used for expansion of the stent  30 . The stent  30  shown here is a self expanding stent although the stent delivery system  10  could be used with a balloon expandable stent. If the stent  30  is a self-expanding stent then the balloon  25  is used only for post-dilatation. If the stent  30  is a balloon expandable stent, then the balloon  25  can be used for both initial deployment and post-dilatation. The system  10  includes an integral fixed guide wire  15  with core wire  16  having a distal tapered section  13 . The system  10  includes a deployment sheath  12  with metal radiopaque distal end  11  that fits over the distal nose piece  18  which is coaxially attached to the fixed guide wire  15 . Under the sheath  12  at the just proximal to the distal nose piece  18  is an expandable embolic filter  22  attached to an expandable/retractable wire basket  20  whose distal end is in turn attached to a radiopaque ring  27 . The embolic filter  22  is a porous material that allows blood to go through it but not embolic debris released during opening of the stenosis. Such embolic filters are currently in use mounted on guide wires and are typically constructed from fabric or plastic. Under the sheath  12 , a stent  30  is coaxially located over an angioplasty balloon  25 . The self expanding stent  30  in this embodiment is longer than the cylindrical portion of the balloon  25  which is positioned to dilate the central portion of the stent after deployment. The stent  30  and balloon  25  are located proximal to the radiopaque ring  27  at the proximal end of the wire basket  20 . Either or both the stent  30  and wire basket  20  may have an anti-thrombogenic coating such as carbon. Elastic distal balloon control band  26  and proximal balloon control band  29  placed coaxially over the ends of the balloon  25  act to refold the angioplasty balloon  25  after inflation. The proximal end of the balloon  25  is coaxially mounted onto the distal end of the plastic tube  21 . The proximal end of the plastic tube  21  is coaxially mounted onto a metal hypotube  14  with balloon inflation lumen  19 . The metal hypotube  14  is typically a thin wall stainless steel tube. The proximal end of the core wire  16  is attached (typically welded) to the hypotube  14   
       FIG. 2A  is an enlargement of the longitudinal cross section of section  2 A of the present invention fixed wire self expanding stent delivery system  10  of  FIG. 1 . The integral fixed guide wire  15  with core wire  16  having a distal tapered section  13  includes a coaxially wrapped helical wire coil  17  with plastic coating  9 . The entire catheter  10  or just the tip would be typically lubricity coated. The system  10  includes a deployment sheath  12  with metal radiopaque distal end  11  that fits over the distal nose piece  18  which is coaxially attached to the plastic coating  9  of the fixed guide wire  15 . Under the sheath  12  at the just proximal to the distal nose piece  18  is an expandable embolic filter  22  attached to an expandable/retractable wire basket  20  whose distal end is in turn attached to a radiopaque ring  27 . A plastic member  23  is attached to the core wire  16  under and extending proximally from the wire basket  20 . The angioplasty balloon  25  with balloon control band  26  is coaxially mounted onto the proximal end of the member  23 . Under the sheath  12 , a stent  30  is coaxially located over an angioplasty balloon  25 . The stent  30  and balloon  25  are located proximal to the radiopaque ring  27  at the proximal end of the wire basket  20 . The stent distal radiopaque marker band  31  is mounted coaxially over the member  23  at a location just distal to the distal end of the stent  30 . The balloon distal radiopaque marker band  32  is mounted coaxially onto the core wire  16  and marks the distal end of the cylindrical portion of the balloon  25  when expanded. A plastic tube  33  is shrunk over the marker band  32  and core wire  16  so as to protect the inside of the folded balloon  25  from coming in contact with the metallic band  32 . The space between the angioplasty balloon  25  and the shrunk plastic tube  33  is the balloon inflation lumen  19 . 
       FIG. 2B  is an enlargement of the longitudinal cross section of section  2 B of the present invention fixed wire self expanding stent delivery system  10  with sheath  12  of  FIG. 1 .  FIG. 2B  shows the proximal ends of the stent  30  and angioplasty balloon  25  with proximal control band  29 . The proximal end of the balloon  25  is coaxially mounted onto the distal end of the plastic tube  21 . The balloon proximal radiopaque marker band  33  is mounted coaxially onto the core wire  16  and marks the proximal end of the cylindrical portion of the balloon  25  when expanded. An optional plastic tube  17  is shrunk over the marker band  33  and core wire  16  so as to protect the inside of the folded balloon  25  from coming in contact with the metallic band  33 . The stent proximal radiopaque marker band  34  is mounted coaxially over the plastic tube  21  at a location just proximal to the proximal end of the stent  30 . The proximal end of the plastic tube  21  is coaxially mounted onto the hypotube  14  with balloon inflation lumen  19 . The proximal end of the core wire  16  is attached (typically welded) to the hypotube  14  near its distal end. 
       FIG. 2C  is a longitudinal cross section of the proximal end of the stent delivery system  10  of  FIG. 1 . The sheath  12  is coaxially mounted onto the distal end of the Tuohy-Borst fitting  35  with side port  36 , proximal hub  38  and elastomer sealing ring  37 . The proximal luer fitting  39  for balloon inflation is attached to the hypotube  14  and in fluid communication with the balloon inflation lumen  19 . With the Tuohy-Borst fitting  35  tightened over the hypotube  14 , no fluid such as blood will leak out of the system  10 . When the Tuohy-Borst fitting is loosened and slid in the proximal direction it will cause the sheath  12  to slide back releasing the wire basket  20  and filter  22  of  FIG. 2A . Subsequent proximal movement of the Tuohy-Borst  35  and sheath  12  will slide back over the ring  27  and collapse the wire basket  20  so the system  10  can be removed from the body. 
       FIG. 3A  is a longitudinal cross section of the distal section of a stent delivery system  40  with integrated distal protection that is delivered over a guide wire  50 . The system  40  with stent  60  includes a sheath  42  with radiopaque metallic distal end  41  that fits over the distal nose piece  48  that is coaxially mounted over the guide wire tube  51 . The system  40  includes an angioplasty balloon  55  to be used for expansion of the stent  30 . The stent  60  shown here is a balloon expandable stent although the stent delivery system  40  could be used with a self expanding stent. If the stent  60  is a balloon expandable stent, then the balloon  55  can be used for both initial deployment and post-dilatation. If the stent  60  is a self-expanding stent then the balloon  55  is used only for post-dilatation. The balloon expandable stent  60  shown here is just a slight bit (e.g. 1-2 mm) shorter than the cylindrical portion of the balloon  55 . With a self expanding stent, it may be desirable to have the stent  60  be longer than the cylindrical portion of the balloon  55  as is shown in  FIG. 1 . Under the sheath  42  at the just proximal to the distal nose piece  48  is an expandable embolic filter  53  attached to an expandable/retractable wire basket  52  whose distal end is in turn attached to a radiopaque ring  57 . Under the sheath  42 , the stent  60  is coaxially located over an angioplasty balloon  50 . The balloon  55  is located proximal to the radiopaque ring  57  at the proximal end of the wire basket  52 . The distal end of the balloon  55  is coaxially mounted onto the guide wire tube  51  at a location just proximal to the ring  57 . The proximal end of the balloon  55  is coaxially mounted onto the distal end of the plastic tube  44 . Elastic distal balloon control band  56  and proximal balloon control band  59  placed coaxially over the ends of the balloon  55  act to refold the angioplasty balloon  55  after inflation. The stent  60  is mounted between the control bands  56  and  59 . A second advantage of the control bands  56  and  59  is that they help the balloon  55  inflate more uniformly to expand the stent  55  without first popping open at the ends which can cause injury to the vessel. The proximal end of the balloon  55  is coaxially mounted onto the distal end of the plastic tube  44 . The space between the plastic tube  44  and the guide wire tube  51  is the balloon inflation lumen  49 . Proximal and distal radiopaque marker bands  62  and  63  respectively mark the ends of the cylindrical portion of the balloon  55  and the balloon expandable stent  60 . The system  40  can be either an over the wire or rapid exchange type system. 
       FIG. 3B  shows a longitudinal cross section of the proximal end of the over the wire version of the system  40  of  FIG. 4A . The sheath  42  is coaxially mounted onto the distal end of the Tuohy-Borst fitting  65  with elastomer sealing ring  68 , side port  67  and proximal hub  66 . The proximal luer fitting  64  with lumen  69  for balloon inflation is attached to the guide wire tube  51  and the plastic tube  44 . The lumen  69  is in fluid communication with the balloon inflation lumen  49  located between the plastic tube  44  and the guide wire tube  51 . With the Tuohy-Borst fitting  65  tightened over the plastic tube  44 , no fluid such as blood will leak out of the system  40 . When the Tuohy-Borst fitting is loosened and slid in the proximal direction it will cause the sheath  42  to slide back releasing the wire basket  52  and filter  53  of  FIG. 3A . Subsequent proximal movement of the Tuohy-Borst  65  and sheath  42  will slide back over the ring  57  and collapse the wire basket  52  so the system  40  can be removed from the body. 
       FIG. 3C  shows a longitudinal cross section of central portion of the system  40  when it is built as a rapid exchange device. This section is typically between 5 and 40 cm proximal to the distal end of the system  40 . In this section the guide wire tube  51 , exits from inside the plastic tube  44  allowing the guide wire  50  to be outside of the catheter  40  in the proximal direction. FIG.  3 C show the configuration of the sheath  42  after it has been fully retracted in the proximal direction with the slot  54  in the sheath extending from just distal to the exit of the guide wire tube  51 . The slot must be as long or slightly longer than the length needed to slide the sheath back and forth. Like most rapid exchange balloon catheters, plastic tube  44  is attached to a proximal hypotube  14  with balloon inflation lumen  19 . In this way, the proximal end of this rapid exchange version is essentially identical to that of the fixed wire system  10  shown in  FIG. 2C , with the sheath having the number  42  instead of  12 . 
       FIGS. 4A through 4G  are longitudinal cross sections that show the steps in deployment of the system  10  of  FIG. 1  to treat an obstructed carotid artery of a human. In  FIG. 4A  the system  10  has exited the guiding catheter or long introducer sheath (not shown) and is positioned at the site of a stenosis in a vessel of a human body. The stent proximal and distal marker bands  34  and  31  respectively are used to locate the stent  30  with its center placed at the center of the stenosis. 
       FIG. 4B  is a longitudinal cross section of the system  10  of  FIG. 1  after the sheath  12  has been pulled back enough to deploy the wire basket  20 ′ with distal protection filter  22 ′. This configuration completely filters the blood distal to the stent  30  through the filter  22 ′ and should catch any distal emboli that result from stent deployment or balloon dilatation. 
       FIG. 4C  is a longitudinal cross section of the system  10  of  FIG. 1  after the sheath  12  has been pulled back completely, the stent  30 ′ has been deployed. 
       FIG. 4D  is a longitudinal cross section of the system  10  of  FIG. 1  after the balloon  25 ′ with control bands  26 ′ and  29 ′ has been inflated to post-dilate the stent  30 ″. 
       FIG. 4E  is a longitudinal cross section of the system  10  of  FIG. 1  after the balloon  25  has been deflated and refolded by the control bands  26  and  29  and the sheath  12  has been advanced until it is over the ring  27  and positioned so that additional distal movement of the sheath  12  will collapse the wire basket  20 ′ with filter  22 ′. 
       FIG. 4F  is a longitudinal cross section of the system  10  of  FIG. 1  before removal from the body but after the radiopaque metallic band  11  of the sheath  12  has been advanced until it engages the distal nose piece  18  so that the wire basket  20  with filter  22  have been completely collapsed. 
       FIG. 4G  shows the artery with expanded stent  30 ″ after the system  10  has been removed. 
       FIG. 5  is a longitudinal cross section of the distal end of the present invention system  70  for the treatment of obstructed vessels of the human body that includes an angioplasty balloon  85  with integrated distal protection. The system  80  includes an integral fixed guide wire  75  with core wire  76  having a distal tapered section  73 . The system  70  includes a deployment sheath  72  with metal radiopaque distal end  71  that fits over the distal nose piece  78  which is coaxially attached to the fixed guide wire  75 . Under the sheath  72  at the just proximal to the distal nose piece  78  is an expandable embolic filter  82  attached to an expandable/retractable wire basket  80  whose distal end is in turn attached to a radiopaque ring  88 . The balloon  85  is located proximal to the radiopaque ring  88  at the proximal end of the wire basket  80 . Elastic distal balloon control band  86  and proximal balloon control band  89  placed coaxially over the ends of the balloon  85  act to refold the angioplasty balloon  85  after inflation. The distal end of the balloon  85  is coaxially mounted onto the proximal end of the plastic member  83  that is coaxially located over the core wire  76  proximal to the distal nose  78 . The proximal end of the balloon  85  is coaxially mounted onto the distal end of the plastic tube  81 . The proximal end of the plastic tube  81  is coaxially mounted onto the hypotube  74  with balloon inflation lumen  79 . Radiopaque marker bands  84  and  87  are coaxially mounted onto the core wire  76  at locations corresponding to the ends of the cylindrical portions of the balloon  85  when inflated. An optional heat shrink tube  77  is placed over the radiopaque marker bands  84  and  87  and the core wire  76  so as to prevent the inside of the balloon  85  from coming into contact with the marker bands  84  and  87 . The proximal end of the core wire  76  is attached (typically welded) to the hypotube  74 . The proximal end of the system  70  is identical to that of the system  10  of  FIG. 1  whose proximal end is shown in  FIG. 2C . 
       FIG. 6  is a longitudinal cross section of the distal section of a balloon angioplasty catheter  90  with integrated distal protection that is delivered over a guide wire  50 . The system  90  with includes a sheath  92  with radiopaque metallic distal end  91  that fits over the distal nose piece  98  that is coaxially mounted over the guide wire tube  94 . The system  90  includes an angioplasty balloon  105 . Under the sheath  92  just proxial to the distal nose piece  98  is an expandable embolic filter  102  attached to an expandable/retractable wire basket  100  whose distal end is in turn attached to a radiopaque ring  108 . The balloon  105  is located proximal to the radiopaque ring  108  at the proximal end of the wire basket  100 . Elastic distal balloon control band  106  and proximal balloon control band  109  placed coaxially over the ends of the balloon  105  act to refold the angioplasty balloon  105  after inflation. The distal end of the balloon  105  is mounted onto the guide wire tube  94 . The proximal end of the balloon is coaxially mounted onto the distal end of the plastic tube  93 . The space between the plastic tube  93  and the guide wire tube  44  is the balloon inflation lumen  99 . Proximal and distal radiopaque marker bands  107  and  104  respectively mark the ends of the cylindrical portion of the balloon  104 . The system  90  can be either an over the wire or rapid exchange type system as was shown for the system  40  of  FIG. 3A . 
       FIG. 7  is a longitudinal cross section of the distal end of the present invention system  110  for the treatment of obstructed vessels of the human body that includes a self expanding stent  130  with integrated distal protection. The system  110  includes an integral fixed guide wire  115  with core wire  116 . The proximal section of the core wire  116  is covered by a plastic tube  123 . The system  110  includes a plastic deployment sheath  11  that fits over the distal nose piece  118  which is coaxially attached to the fixed guide wire  115 . Under the sheath  112  just proximal to the distal nose piece  118  is an expandable embolic filter  122  attached to an expandable/retractable wire basket  120  whose distal end is in turn attached to a radiopaque ring  128 . The self expanding stent  130  is located proximal to the radiopaque ring  118  at the proximal end of the wire basket  120 . Radiopaque marker bands  124  and  127  are coaxially mounted onto the plastic tube  123  at locations corresponding to the ends of the stent  130 . The proximal end of the system  110  includes a mechanism similar to that of  FIG. 2C  where the hypotube is replaced by the tube  123 . 
       FIG. 8  is a longitudinal cross section of the distal section of a self expanding stent delivery system  140  with integrated distal protection that is delivered over a guide wire  50 . The system  140  with includes a sheath  142  with radiopaque metallic distal marker band  141  that fits over the distal nose piece  148  that is coaxially mounted over the guide wire tube  144  with guide wire lumen  149 . The system  140  includes a self expanding stent  160 . Under the sheath  142  at the just proximal to the distal nose piece  148  is an expandable embolic filter  152  attached to an expandable/retractable wire basket  150  whose distal end is in turn attached to a radiopaque ring  158 . An additional radiopaque marker band  145  is coaxially mounted onto the guide wire tube  144  just proximal to the nose piece  148 . The two markers  141  on the sheath and  145  on the guide wire tube allow visualization as to when the sheath is fully advanced in the distal directions which clearly indicates that the filter basket  150  has been fully collapsed. This approach using two marker bands could also be applied to the systems shown in  FIGS. 1 through 7 . The self expanding stent  160  is located proximal to the radiopaque ring  158  at the proximal end of the wire basket  150 . Proximal and distal radiopaque marker bands  157  and  154  respectively mark the ends of the stent  160 . The system  140  can be either an over the wire or rapid exchange type system as was shown for the system  40  of  FIG. 3A . 
     It is envisioned that the filter basket may be made of a radiopaque material such as tantalum or an alloy with embedded tungsten such as L605 so as to make visualization of the expansion and retraction of the filter basket and filter easier under fluoroscopy. It is also envisioned that if the filter basket is made of a memory metal such as NITINOL then it may have one or more radiopaque markers placed on or inside it such as a gold marker. It is also envisioned that the entire filter basket might be electroplated with a radiopaque metal such as gold or platinum. 
     In all these examples is should be clear that any of the configurations can be developed to be over the wire, rapid exchange or fixed wire systems. The self expanding stents would typically be made of NITINOL while the balloon expandable stents would typically be made from 316L surgical grade stainless steel, L605, another suitable cobalt chromium alloy or a layered metallic tube having at least one layer of a radiopaque metal such as tantalum. Any of the stents may also be drug eluting using one or more drugs. Typical drugs would include the -imus drugs of Sirolimus and Everolimus. The stents may also be carbon coated to reduce sub acute thrombosis. 
     It is envisioned that the self expanding stent versions of the present invention would be ideally suited to carotid arteries and above the knee SFA and Popliteal arteries. The balloon expandable version of the present invention would have best application to the treatment of myocardial infarction. 
     Various other modifications, adaptations, and alternative designs are of course possible in light of the above teachings. Therefore, it should be understood at this time that within the scope of the appended claims the invention may be practiced otherwise than as specifically described herein.