Abstract:
An endoluminal device adapted to be deployed in a branched body lumen is provided by intraluminal delivery from an access location remote from the location at which the device is to be deployed, i.e. by introduction through one of the branches of the branched body lumen. The device comprises an unbranched portion, a first branch portion and second branch portion in communication with the unbranched portion, and a distortion element removeably connected to the first branch portion for manipulating the geometry of the second branch portion. The distortion element extends along the first branch portion and back to the access location.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     It is known to treat an abdominal aortic aneurysm (AAA) by endoluminally implanting a bifurcated stent-graft in order to bypass the aneurysm. Stent-grafts adapted for this use include a number of designs. A large class of these designs incorporates a modular aspect that brings the benefits of reducing the size of each individual sub-component to be implanted and facilitating a customized fit for each patient. A downside of modular design is that it necessitates in situ assembly of the sub-components. A common in situ assembly process of a two-piece device includes an initial insertion of a bifurcated component whose branch portions are of differing lengths; so called “long leg-short leg devices.” The bifurcated component is inserted from a remote location into and up an ipsilateral iliac artery and positioned in the aortic neck so that the second branch portion directs luminal flow into the contralateral iliac artery. Next, a leg extension component is engaged with the second branch portion to extend the bifurcated device into the contralateral iliac artery. This can be achieved by inserting a guidewire from a remote location into the contralateral iliac artery and through the aperture of the second branch portion. The leg extension component is then delivered along the guidewire and into engagement with the second branch portion of the bifurcated component.  
         [0002]     In patients with large saccular aneurysms, the aortic neck is typically angularly offset significantly from the iliac arteries. The offset hinders insertion of the leg extension component guidewire into the second branch portion aperture because the guidewire approaches the aperture from an acute angle.  
       SUMMARY OF THE INVENTION  
       [0003]     The present invention relates to a prosthetic device for facilitating endoluminal assembly of a modular bifurcated endoluminal device in a branched body lumen from a remote location. The invention is particularly advantageous in the treatment of large saccular AAA&#39;s with a distorted aortic neck.  
         [0004]     Generally, an endoluminal device is adapted to be deployed in a branched body lumen, from an access location remote from the location at which the device is to be deployed, by introduction through one of the branches of the branched body lumen. The device comprises an unbranched portion and at least two branch portions in communication with said unbranched portion. The branch portions comprise a first branch portion adapted to be deployed in one branch of the body lumen and a second branch portion adapted to be directed toward a second branch of the body lumen. The device further comprises a distortion element removeably connected to the second branch portion for manipulating the geometry of the second branch portion. The distortion element extends along the first branch portion to the access location. The distortion element can be an elongated filament such as a wire, a yarn, or a cable. The removable connection can be a slipknot, a ring, or an eyelet. Optionally, the present invention also includes: a second endoluminal device adapted to be mated with the second branch portion of the first device; the methods for using and inserting those devices, and apparatus therefore. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0005]     The invention is best understood from the following detailed description when read in connection with the accompanying drawings. It is emphasized that, according to common practice, the various features of the drawings are not to scale. On the contrary, the dimensions of the various features may be arbitrarily expanded or reduced for clarity. Included in the drawings are the following Figures:  
         [0006]      FIG. 1  illustrates a typical large saccular aneurysm having an offset neck;  
         [0007]      FIG. 2A  illustrates a prior art bifurcated endoluminal device having a long leg and a second branch portion;  
         [0008]      FIG. 2B  illustrates use of the prior art device depicted in  FIG. 2A  in a distorted aneurysm;  
         [0009]      FIG. 3A  illustrates a first device embodiment of the present invention;  
         [0010]      FIG. 3B  illustrates the device of  FIG. 3A  in use in a distorted aneurysm;  
         [0011]      FIG. 3C  illustrates the device of  FIG. 3A  in use in a distorted aneurysm showing attachment of an optional leg extension;  
         [0012]      FIG. 4A  illustrates a second device embodiment of the present invention;  
         [0013]      FIG. 4B  illustrates the device of  FIG. 4A  in use in a distorted aneurysm;  
         [0014]      FIG. 4C  illustrates the device of  FIG. 4A  in use in a distorted aneurysm showing attachment of an optional leg extension;  
         [0015]      FIG. 5A  illustrates an introducer embodiment according to the present invention showing the loaded endoluminal device fully collapsed within the introducer;  
         [0016]      FIG. 5B  illustrates the introducer of  FIG. 5A  with the loaded endoluminal device partially deployed;  
         [0017]      FIG. 5C  illustrates the introducer of  FIG. 5A  with the loaded endoluminal device deployed;  
         [0018]     FIGS.  6 A-C are cross-sectional views of the loaded introducer shown in  FIG. 5A  at the respective cross-section planes  6 A- 6 A,  6 B- 6 B, and  6 C- 6 C;  
         [0019]      FIG. 7  illustrates an exemplary second introducer for deployment of a leg-extending second device;  
         [0020]      FIG. 8A  illustrates an optional embodiment of the device including an everted leg in use in a distorted aneurysm; and  
         [0021]      FIG. 8B  illustrates the everted leg embodiment of  FIG. 8A  with the everted leg deployed.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0022]     The invention will next be illustrated with reference to the figures wherein the same numbers indicate similar elements in all figures. Such figures are intended to be illustrative rather than limiting and are included herewith to facilitate the explanation of the apparatus of the present invention.  
         [0023]      FIG. 1  illustrates an exemplary AAA having a large saccular portion  15  and a tortured neck  10  distorted from its natural vertical alignment. Ipsilateral iliac artery  20  and contralateral iliac artery  30  are also indicated.  FIG. 2A  depicts a bifurcated “long leg-second branch portion” prosthetic device used in the prior art to treat AAA&#39;s.  FIG. 2B  illustrates the difficulties in an exemplary prior art device being implanted in a large saccular AAA having a tortured neck.  
         [0024]     As proposed herein and as shown in  FIG. 3A , an embodiment of the present invention is a bifurcated endoluminal device  100  that includes a distortion element  140  removeably connected to second branch portion  130 . Distortion element  140  can take the form of any elongated filament that is capable of translating a pulling force from a remote location to the second branch portion  130 . Examples of a suitable elongated filament are a wire, yarn, or cable. Distortion element  140  is connected to second branch portion  130  by a removable connection means  150  such as a slipknot, ring, or eyelet by which distortion element  140  can be detached following its use.  
         [0025]      FIG. 3B  shows the device in usewhereby distortion element  140  enables the surgeon to effectively pull second branch portion  130  toward first branch portion  120  by applying tension or otherwise manipulating distortion element  140 . Thus, the surgeon is able to facilitate the location of open end  160  of second branch portion  130  with guidewire  610 . Using guidewire  610 , the surgeon can optionally deploy and mate a second device ( 200 ) to second branch portion ( 130 ) using second introducer  600  (an example of which is illustrated at  FIG. 7 ) as needed to extend second branch portion ( 130 ) as shown in  FIG. 3C . When distortion element  140  is no longer needed it can be detached from second branch portion  130  by detaching removeable connection means  150  and pulling it through the ipsiliateral iliac  30 . Preferably, removal is performed through introducer  500  (discussed further below) by which device  100  was originally introduced. For example, where connection means  150  is a slipknot, simply pulling on the slipknot to untie it and then pulling distortion element  140  through introducer  500 . Likewise, where connection means  150  is a slip ring, pulling one end of distortion element  140  through the slip ring and then pulling distortion element  140  through introducer  500 .  
         [0026]     As further proposed herein and as shown in  FIG. 4A , another embodiment of the present invention is a bifurcated endoluminal device  300 . Bifurcated device  300  includes the features of bifurcated device  100  and further incorporates a removeable pivot point means  310  positioned on first branch portion  120  of device  300 . Pivot point means  310  serves as an axis around which pulling force exerted by the surgeon can be re-directed laterally towards second branch portion  130 . Pivot point means  310  may be any structure capable of performing this redirection such as a ring, hook, button, or nipple.  FIG. 4B  illustrates use of pivot means  310  in combination with distortion element  140  and connection means  150  to orient second branch portion  130  to facilitate insertion of guidewire  610 . Using guidewire  610 , the surgeon can optionally deploy and mate a second device ( 200 ) to second branch portion ( 200 ) using second introducer ( 600 ) as needed to extend second branch portion ( 130 ) as shown in  FIG. 4C .  
         [0027]     While the invention may be introduced in any number of ways which may be devised by those skilled in the art, one way of doing so is by the deployment apparatus illustrated in  FIGS. 5A, 5B ,  5 C and  6 A,  6 B, and  6 C.  
         [0028]     More specifically, in  FIG. 5A  and in  FIGS. 6A, 6B , and  6 C there is shown bifurcated endoluminal device  100  compressed for endoluminal placement in an outer sheath  520  and mounted on guidewire tube  570  through which extends guidewire  560 , extending from the external access point, where the delivery apparatus enters the vasculature, to a nose cone  510  just distal (with respect to the access point) of device  100 . An inner sheath  530  terminates just proximal of the proximal end of second branch portion  130  and a pusher element  550  is disposed just proximal of first branch portion  10 . Distortion element  140 , attached to second branch portion  130  by removeable connection means  150 , includes a return length or lengths extending within outer sheath  520  in a distortion element channel  540  to the external access point.  
         [0029]     It will be noted that inner sheath  530  generally occupies the space within outer sheath  520  not otherwise occupied by pusher element  550  except for distortion element channel  540  which permits passage of distortion element  140 .  
         [0030]      FIG. 5B  illustrates deployment of bifurcated endoluminal device  100  as outer sheath  520  is retracted to the point where second branch portion  130 , unbranched portion  110 , and a portion of first branch portion  120  are expanded, in this case by the self expansion characteristics of their elasticity or memory metal composition. At this stage, tension can be applied to distortion element  140  (or otherwise manipulating distortion element  140 ), thereby constraining second branch portion  130  to a limited angular separation from first branch portion  120  and thus second branch portion  130  can be better aligned with contralateral iliac  30  (as seen in  FIG. 3B ).  
         [0031]     Sequentially,  FIG. 5C  shows the final deployment stage of bifurcated endoluminal device  100  when outer sheath  520  and inner sheath  530  are both withdrawn to the point where the remainder of first branch portion  120  is deployed. As shown in  FIG. 3B , with distortion element  140  effecting some control over the angular disposition of second branch portion  130 , capture of bifurcated endoluminal device  100  from contralateral iliac  30  can then be performed by passing guidewire/snag wire  610  from contralateral iliac  30  into open end  160 . Thereafter, guidewire/snagwire  610  can be used, for example, to guide second introducer  600  for deploying and mating a leg-extending second device  200  to second branch portion  130 .  
         [0032]     As shown in  FIG. 8 , an optional embodiment of bifurcated device  100  alternatively provides for the second branched portion as an everted leg ( 800 ). This optional embodiment is deployed in the same manner as previous embodiments. However, to provide an extended second branch portion the surgeon inserts snagline  620  into open end ( 810 ) of the everted leg. As above, distortion element  140  can be used to orient open end ( 810 ) to facilitate insertion of snagline  620 . Using snagline  620 /the surgeon can then pull everted leg  800  down and into contralateral iliac artery  30 . An advantage of this embodiment has an advantage in that in many applications would required no further leg extension of the second branch portion.  
         [0033]     Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, the claims which follow are intended to be construed to encompass any modifications which may be made by those skilled in the art to which this invention pertains that nevertheless lie within the spirit and scope of this invention.