Abstract:
A router device is a intraluminal prosthesis which is used in the repair of aneurysms and other diseases of the aorta. The device also has applications in other vascular beds. The device incorporates an inflatable cuff or sequence of cuffs at one end for fixation and sealing. This cuff may be placed proximal to branch vessels of the aorta. Attached to the cuff is a tubular graft consisting of a generally cylindrical graft material. The graft material may contain one or more fenestrations, intended to align with branch vessels as they emerge from the parent vessel, the aorta in the preferred embodiment. The device features a deliberate taper of its diameter as the device crosses the area of branch vessels. This taper brings the diameter of the graft material to a lesser diameter than that of the parent vessel, leaving a deliberate and distinct space between the device and the wall of the vessel. This space allows more easily achieved engagement of the branch vessels with stents using standard catheterization techniques.

Description:
CLAIM OF PRIORITY 
       [0001]    This application claims priority from U.S. Provisional Patent Application Ser. No. 61/214,449, filed Apr. 23, 2009, currently pending. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates generally to an intra-luminal prosthesis for repair of body conduits. More specifically, the invention relates to an intra-arterial prosthesis to aid in the repair of an abnormal vessel. 
       BACKGROUND 
       [0003]    Various tubular vessel structures within the human body, such as the biliary duct system, excretory system and vascular system, may deteriorate so that medical repair is necessary. For example, aortic aneurysms are abnormal ballooning out of the wall of the vessel, and put a person at risk of death from rupture of the aneurysm. These aneurysms most commonly involve the abdominal aorta just below the level of the arteries that supply the kidneys. The second most common location for such aneurysms is in the thoracic aorta, adjacent to the major branches which supply the head and arms. 
         [0004]    Endovascular devices for repairing such aneurysms are known in the art. Several have been commercialized, including those made by Cook Vascular Incorporated of Vandergrift, Pa., W.L. Gore &amp; Associates Inc. of Flagstaff, Ariz., Medtronic Inc. of Minneapolis, Minn. and Endologix, Inc. of Irvine, Calif. Such prior art devices are generally introduced through a vessel in the groin and tracked over a guidewire. The devices are typically introduced in a constrained condition, so as to allow access through the relatively smaller groin artery. 
         [0005]    The prior art devices have significant similarities in terms of their overall structure. They are usually modular, in which a “main body” is introduced as one device, with a method of fixation and sealing incorporated into the proximate component, and an “ipsilateral limb”, which extends into the iliac artery. There is a “gate” as part of the main body, which is then cannulated from the contralateral groin so that a “contralateral limb”, a tubular stent-graft component, may be deployed to complete the two-piece endograft system. 
         [0006]    In the thoracic aorta, the design is generally simpler, as the aorta does not branch over the course of the descending thoracic aorta. Hence there is only a single, tubular component to the endograft device. 
         [0007]    In both the abdominal and thoracic aorta, the primary anatomic limitation to the success of aneurysm exclusion is the proximity of the major branch vessels to the aneurysm itself. The interval between the last major branch vessel and the aneurysm is referred to as the “neck.” Prior art devices generally specify in their Instructions For Use (IFU&#39;s) a minimum neck length for which each device is approved for use. Adequate neck length is critical for achieving a seal between the device and the normal aortic wall. If this length is too short, there may be insufficient wall contact to effectively exclude the aneurysm, leading to persistent flow in the aneurysm, or “endoleak”. 
         [0008]    Unfortunately, the necks of both abdominal aortic aneurysms (AAA&#39;s) and thoracic aortic aneurysms (TAA&#39;s) are often too short for reliably successful endograft placement. In such cases, open surgical repair may be the only option. Many of the patients with AAA or TAA, however, have other conditions that make them very poor open surgical candidates, and hence no good option is available for their treatment. 
         [0009]    In the past several years, many experimental techniques have been developed in an attempt to remedy this problem. These fall primarily into the categories of branched endografts and “fenestrated” endografts. Each involves a modified stent graft, with either holes created to align with the branch vessels (fenestrated), or pre-attached branch limbs which engage the branch vessels. In order to ensure proper alignment of these devices, extremely elaborate systems of guidewires are employed to pre-engage the branch vessels. This is a complex process which is beyond the skill set of many endovascular specialists, and makes such procedures difficulty to perform, lengthy, and more likely to produce complications. 
         [0010]    In addition, all of the currently available endograft systems depend on a metallic endoskeleton for fixation, which is achieved through continuously outward frictional force generated by the spring-like metal. The metal, however, is relatively stiff, and hence does not conform well to the aorta when there is significant tortuosity of the vessel, or angulation of the vessel segments. Furthermore, the endografts fully supported by this metallic endoskeleton cannot be repositioned once deployed. Hence any malalignment of the endograft with side branches cannot be corrected, and this constitutes a potentially catastrophic limitation. For these reasons, adoption of fenestrated endografts has been extremely limited, and this has greatly limited the options available to a large subgroup of patients with life-threatening aneurysms. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a perspective view of an embodiment of the router device of the present invention with a cross-sectional view of the deployment catheter attached to the router device; 
           [0012]      FIGS. 2A and 2B  are cross-sectional views of the deployment catheter of  FIG. 1  with the router device removed and with the router device in a collapsed condition over the catheter, respectively; 
           [0013]      FIGS. 3A and 3B  are enlarged perspective views of an embodiment of the inflation port and valve of the inflatable cuff of  FIG. 1  and the inflation stem of the catheter of  FIG. 2A  with the stem disengaged from the port and valve and the stem engaging the port and valve, respectively; 
           [0014]      FIGS. 4A-4D  are cross-sectional views of an abdominal aortic aneurysm and branch arteries with the router device and catheter of  FIGS. 1-3B , a endograft device and stents being deployed therein in accordance with an embodiment of the method of the present invention; 
           [0015]      FIGS. 5A-5C  are cross-sectional views of the aorta and renal arteries of  FIGS. 4A-4D  taken along line  5 - 5  of  FIG. 4D  showing the positioning and attachments of stents to the router device in accordance with an embodiment of the method of the present invention; 
           [0016]      FIGS. 6A-6C  are cross-sectional views of a thoracic aortic aneurysm and branch arteries with an embodiment of the router device of the present invention, an endograft device and stents being deployed therein in accordance with an embodiment of the method of the present invention; 
           [0017]      FIG. 7  is a side elevational view of a tubular graft wall of an embodiment of the router device of the present invention with a malleable portion surrounding a fenestration; 
           [0018]      FIGS. 8A-8C  are cross-sectional views of the aorta showing the positioning and attachments of a stent to the fenestration of the router device of  FIG. 7  in accordance with an embodiment of the method of the present invention; 
           [0019]      FIG. 9  is a side elevational view of a tubular graft wall of  FIG. 8C  taken in the direction of arrow  9  in  FIG. 8C . 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0020]    The present invention is directed towards an intraluminal prosthesis for aiding in the repair of an abnormal tubular vessel of a patient. In preferred embodiments, described below, the present invention is used in the repair of aortic aneurysms. 
         [0021]    With reference to  FIG. 1 , a preferred embodiment of the router device is indicated in general at  20 . The device  20 , shown in its inflated and deployed configuration, consists of a generally tubular structure, having a proximal or first end, indicated in general at  22 , provided with an arrangement for affixing the device to the interior surface of the artery. In the preferred embodiment, this fixation consists of an inflatable element, preferably in the form of an inflatable cuff  24  incorporated into the first end of the device. 
         [0022]    The cuff  24  is preferably composed of bioinert, polymeric plastic, and, as illustrated in  FIG. 1 , is of cylindrical shape and defines a comparatively large central opening  32  surrounded by the relatively thin inflatable element (the inflatable cuff  24 ). An annular inflatable chamber, a section of which is indicated in phantom at  23  in  FIG. 1 , is defined between the outer and inner surfaces of the cuff, indicated at  25  and  27 , respectively. When deployed, the inflatable cuff  24  is disposed transversely within a vessel lumen, juxtaposed circumferentially to the interior surface of the vessel. The cuff preferably includes a friction-enhancing outer surface  25  which may include, for example, circumferential ridges and/or a course texture formed, for example, by a combination of raised and lowered surface portions. In addition, it may be desirable in some applications to provide the cuff with an outer surface that promotes tissue ingrowth. Such a surfaced material could include, for example, TEFLON. 
         [0023]    While one cuff is illustrated in  FIG. 1 , multiple inflatable cuffs may alternatively be provided. In addition, the cuff(s) may take on a variety of configurations and, as described below, may be inflated and deflated, before a final inflation in the desired location is performed. A suitable construction and use of the cuff is disclosed in commonly owned U.S. Pat. No. 6,007,575, the contents of which are hereby incorporated herein by reference. 
         [0024]    The router device also features a generally tubular graft  26  to which the cuff is attached at the proximal end. The tubular graft is preferably constructed from a biocompatible synthetic material, such as DACRON or TEFLON, but is not limited to these two materials. For example, the tubular graft  26  could be made of polyester or polytetrafluoroethylene or any other biocompatible material. In addition, as explained in greater detail below, the tubular graft is provided with a number of fenestrations  28   a - 28   d . While four generally round fenestrations are illustrated in  FIG. 1 , it will be apparent that the tubular graft may be provided with a greater or lesser number of fenestrations and fenestrations of different shapes and sizes. 
         [0025]    The tubular graft at the proximal or first end  22  is of a diameter equal to or slightly greater than the diameter of the non-aneurysmal aortic wall proximate to the aneurysm and branch vessels. The inflatable cuff is intended for positioning proximate to the major branch vessels in either a abdominal aortic aneurysm (AAA) or a thoracic aortic aneurysm (TAA). In the case of a AAA, this proximate location may be above the renal arteries, or above the superior mesenteric artery and renal arteries, or, lastly, above the celiac axis, superior mesenteric artery, and renal arteries. In each of these cases, the construction of the tubular graft component of the device differs: there is one fenestration for each branch vessel. In the case of a suprarenal fixation, therefore, there are two fenestrations; for a supramesenteric fixation, there are three: one for the superior mesenteric artery, and one for each renal artery. There are four fenestrations for the supraceliac fixation, with the last fenestration corresponding to the origin of the celiac axis. 
         [0026]    The positions of the fenestrations ( 28   a - 28   d  of  FIG. 1 ), which are placed as part of the fabrication process of the device, are preferably determined by previously obtained imaging, usually consisting of a computed tomography (CT) scan. Such scans identify very precisely the location of the major branch vessels. The data set is made available to the fabricator of the device, and the fenestrations located accordingly. Alternatively, a standard set of fenestrations may be incorporated into a set of non-customized devices, based on general anatomic data which encompass a certain, presumably large percentage of the population. 
         [0027]    The tubular graft  26  is preferably of a generally tapered configuration, with the diameter of the tubular graft decreasing as the distance from the inflatable cuff increases. The average diameter of the fenestrated section is less than that of the adjacent aortic wall. This is the case whether or not the segment of aorta from which the branch vessels originate is aneurysmal or not. 
         [0028]    As illustrated in  FIGS. 1 and 2B , the inflatable cuff is attached by its inner surface to a deployment catheter  34 . The deployment catheter  34  without the inflatable cuff attached is illustrated in  FIG. 2A . The catheter  34  is preferably constructed of a polymeric plastic which is bioinert and features a central or guidewire lumen  36  and an inflation lumen  38 . 
         [0029]    As illustrated in  FIGS. 1-2B , guidewire lumen  36  passes through the center of catheter  34 , coaxial with the longitudinal axis of the catheter, and is preferably of sufficient diameter to accommodate a guidewire of at least 0.035 inch diameter. The guidewire lumen  36  opens into a port affixed at the proximal end of catheter  34 , which remains outside of the patient&#39;s body. Guidewire lumen  36  is preferably of consistent general diameter throughout its length. 
         [0030]    The distal portion of catheter  34  undergoes a concentric gentle tapering to a size only slightly larger than guidewire lumen  36  at its tip  42 . 
         [0031]    The inflation lumen, indicated at  38  in  FIGS. 1-2B , is disposed parallel to the guidewire lumen  36 , and is used for inflation and deflation of cuff  24 . This lumen may be of any size that allows cuff  24  to be easily inflated or deflated and is generally consistent diameter throughout the length of catheter  34 . As shown in  FIG. 1 , one end of inflation lumen  38  terminates at a junction with cuff  24  so that inflation lumen  38  and cuff  24  are in fluid communication with one another. The other end of inflation lumen  38  emerges from the catheter  34  at a location external to the body of the patient. 
         [0032]    The cuff  24  includes a valve, indicated generally at  37  in  FIGS. 3A and 3B , which is integral with inflation port  39  of cuff  24 . Preferably, valve  37  combines a breakaway valve  43  with a “duck bill” or “mitre” valve  45 . Mitre valve  45  features opposing leaflets  51  and  53  which are constructed of a non-elastomeric, biologically inert material. Breakaway valve  43  features a circumferential rim  55  formed upon the interior surface of inflation port  39 . As illustrated in  FIG. 2A , catheter  34  is provided with an inflation stern  61  having a passage that is in fluid communication with the inflation lumen. As illustrated in  FIGS. 3A and 3B , inflation stem  61  features mating end  63  and circumferential notch  65 . As shown in  FIG. 3B , when inflation stem  61  is in an engaged configuration with valve  37 , mating end  63  separates the opposing leaflets  51  and  53  of mitre valve so that cuff  24  may be inflated or deflated. When in this configuration, again as shown in  FIG. 3B , the circumferential notch  65  of the inflation stem  61  engages the circumferential rim  55  so as to secure inflation stem  61  within inflation port  39 . 
         [0033]    Referring to  FIGS. 3A and 3B , once cuff  24  has been inflated to the desired level, a sharp tug on the catheter  34 , and thus inflation stem  61 , in a direction away from inflation port  39  causes circumferential notch  65  and circumferential rim  55  to disengage. This allows easy withdrawal of mating end  63  from mitre valve  45  and inflation port  39 . Upon withdrawal of the mating end  63  of inflation stem  61 , as shown in  FIG. 3A , opposing leaflets  51  and  53  of mitre valve  45  close to seal the inflated cuff  24 . 
         [0034]    Alternative valve arrangements known in the art may be substituted for the valve  37  of  FIGS. 3A and 3B . 
         [0035]    Referring back to  FIG. 1 , cuff  24  is inflated by way of an inflation syringe  71  with an inflation material  73 . The inflation material could be a saline-based fluid or a material that contains a photo-activated or heat-activated hardening agent or any hardening agent that hardens over time. Typically, the inflation syringe  71  is mounted in a screw-feed pressure generating device provided with a manometer in order to accurately gauge inflation pressures. After cuff  17  has been installed and inflated, the material  73  hardens over time to permanently affix router device within the tubular structure of the body. 
         [0036]      FIGS. 4A-4D  and  5 A- 5 C illustrate the steps to be performed in deploying the aortic router device of  FIG. 1  to treat an abdominal aortic aneurysm in the accordance with an embodiment of the method of the present invention. 
         [0037]    As illustrated in  FIG. 4A  (and  FIG. 2B ), the inflatable cuff  24  and tubular graft  26  are collapsed around the catheter  34  behind catheter tapered portion  42 . Referring to  FIG. 4A , a guide wire  72  is initially fed from outside of the patient&#39;s body, through an incision into the groin artery  75  and finally through the aortic artery and past the aneurysm  74 . The absence of a metal endoskeleton allows the overall size of the router device to be reduced, and hence there is the potential to introduce it through a smaller catheter delivery system. 
         [0038]    Once guide wire  72  is in place, catheter  34 , with the aortic router device collapsed over it, is advanced along guide wire  72  so as to become positioned at the desired location within the artery, as illustrated in  FIG. 4A . As illustrated in  FIGS. 4A and 4B , the desired location positions the fenestrations  28   a - 28   d  in alignment with the branch arteries proximal to the aneurysm  76   a - 76   d.    
         [0039]    As shown in  FIG. 4B , the cuff  24  is next inflated using the technique described above so as to circumferentially engage the interior surface of the aortic wall  78 . As a result, the inflatable cuff achieves both fixation and sealing to the interior surface of the aortic wall. 
         [0040]    Because the aortic router may be positioned without causing damage to the surrounding tissue, it may be deflated and repositioned if the original position is not optimal. More specifically, after the cuff  24  has been inflated so that the router device is affixed to the aortic wall without penetration, the position of the cuff is examined fluoroscopically to determine if it is optimal. If not, the cuff may be deflated, repositioned and then re-inflated. When the optimal position is achieved, the cuff preferably is finally inflated with a hardening agent. 
         [0041]    When this stage of the procedure has been completed, the catheter  34  is disconnected from the inflatable cuff  24  so that the catheter may be removed from the artery. The valve of the cuff described above allows the inflation stem of the catheter to be removed from the cuff inflation port so that the cuff is sealed in an inflated condition. 
         [0042]    Once properly positioned, the router device allows the placement of a commercially available endograft in an otherwise untreatable aneurysm. In the example presented below, the introduction of the endograft precedes the introduction of the covered stent branches. It is to be understood, however, that the method of the present invention could be performed instead in reverse order (covered stent branches introduced before the endograft). 
         [0043]    With reference to  FIGS. 4B and 4C , the distal end  82  of the tubular graft  26  of the router device, in its preferred embodiment, is open ended, so as to form distal lumen  84 , and tapered to a diameter less than that of the endograft to be introduced for aneurysm repair (see also  FIG. 1 ). The distal end  82  of the router device is cannulated during the course of the procedure with a second guidewire, indicated at  86  in  FIG. 4B , and one of the commercially available endografts, indicated in general at  88  in  FIG. 4C , is advanced over the second guidewire and the metallic exoskeleton  92  of the endograft deployed within the distal lumen  84 , as illustrated in  FIG. 4C . The original guidewire  72  may alternatively be used to insert and position the endograft. Because the graft material for the distal end of the tubular graft is of a slightly smaller diameter than the commercial endograft, and is preferably tapered to successively smaller diameter as it extends distal, the metallic exoskeleton of the deployed endograft forms a frictional fit seal with essentially no risk for distal migration. Again, the endograft deployment may take place before the branch covered stents are introduced, but may also be done afterwards. 
         [0044]    It is important to note that at no time is flow to branch vessels  76   a - 76   d  interrupted during deployment of the router and the endograft device. Hence, the router device may actually be placed during an earlier procedure, and the introduction of the endograft may be accomplished during a later procedure, if the patient cannot tolerate a more prolonged procedure or the physician prefers for whatever reason to stage the procedure. 
         [0045]    Once the cuff  24  has been inflated with a hardening agent and secured to the wall, the fenestrations  28   a - 28   d  ( FIGS. 4B and 4C ) are cannulated separately, and bridging small covered stents, illustrated at  96   a - 96   d  in FIGS.  4 D and  5 A- 5 C, are deployed. Suitable stents are well known in the art and are commercially available from, for example, W.L. Gore &amp; Associates Inc. of Flagstaff, Ariz., C.R. Bard, Inc. of Murray Hill, N.J. and Atrium Medical Corporation of Hudson, N.Y. As is known in the art, such stents are initially introduced into a vessel in a collapsed condition and then expand for affixing to the interior wall of a vessel or other structure. Furthermore, the stent of commonly owned U.S. Pat. No. 6,007,575 may be used. 
         [0046]    As illustrated in  FIG. 5A , guidewires  102   c  and  102   d  are inserted into the patient&#39;s renal arteries  76   c  and  76   d  and the stents  96   c  and  96   d  are moved, in a collapsed condition, over the guidewire and into position within the corresponding fenestrations  28   c  and  28   d . As illustrated in  FIG. 5B , the stents  96   c  and  96   d  are then expanded so that they engage the fenestrations  28   c  and  28   d  ( FIGS. 4B ,  4 C and  5 A) in an interference fit fashion, and are thus secured to and within, the fenestrations of the tubular graft  26  of the router device. The guidewires may them be removed from the renal arteries, as illustrated in  FIG. 5C . Stents  96   a  and  96   b  of  FIG. 4D  may be positioned within, and attached to, fenestrations  28   a  and  28   b  of the tubular graft  26  of the router device in a similar fashion. Alternative methods and arrangements known in the art may be used to attach the stents to the fenestrations of the tubular graft in place of the method and arrangement described above. 
         [0047]    Flow through the aorta is maintained throughout the process. Thus, even in procedures of long duration, and as noted previously, flow is maintained to all branch vessels. The absence of the endoskeleton in the router device allows for the more easy tapering of the tubular graft immediately below the level of the cuff. This taper to a smaller diameter creates a slightly wider gap between the tubular graft of the router device and the branch vessel origins. This is extremely beneficial as it allows cannulation of sidebranches even if the alignment of the fenestration is suboptimal. This greatly reduces the precision required in the deployment of the device, and greatly increases the ease with which the branch vessels may be cannulated via the corresponding fenestrations. 
         [0048]    As illustrated in  FIG. 4D , the placement of the covered stents  96   a - 96   d  through the fenestrations of the tubular graft  26  of the router device to create branch connections, in combination with the attachment of the endograft  88  to the distal end of the router device, creates a sealed continuous inner lumen which effectively excludes the aneurysm  74  from the circulation. 
         [0049]      FIGS. 6A-6C  illustrate the steps to be performed in deploying an embodiment of the router device, indicated in general at  120 , to treat a thoracic aortic aneurysm  122  in the accordance with an embodiment of the method of the present invention. 
         [0050]    The router device  120  features a construction similar to the router device  20  of  FIGS. 1-5C , the exception being that it features two inflatable cuffs  124   a  and  124   b  attached to the proximal end of the tubular graft  126 . Each cuff features its own inflation port and valve, each of the type illustrated at  39  and  37  in  FIGS. 3A and 3B , and the catheter features two inflation stems (each of the type illustrated at  61  in  FIGS. 3A and 3B ) that are in fluid communication with the catheter inflation lumen and that removably engage the inflation ports of the two cuffs. 
         [0051]    The router device is initially inserted into the thoracic artery in a collapsed condition over a catheter using a guidewire  122 , as described above with respect to  FIGS. 4A and 4B . 
         [0052]    The catheter, with the aortic router device collapsed over it, is advanced along guide wire  122  so as to become positioned at the desired location within the artery. As illustrated in  FIG. 6A , the cuffs  124   a  and  124   b  are inflated with the router device in the desired location, that is, with the fenestrations  128   a - 128   c , in alignment with the branch arteries proximal to the aneurysm  136   a - 136   c . As described above with respect to  FIG. 4B , the catheter is removed from the artery when the router device has been optimally positioned and the cuffs inflated with a hardening agent. 
         [0053]    As illustrated in  FIG. 6B , once the router device  120  is properly positioned, its tapered distal end  140  is cannulated and a commercially available endograft  138  is attached therein by way of the endograft&#39;s metallic exoskeleton  144 . In the example presented below, the introduction of the endograft precedes the introduction of the covered stent branches. It is to be understood, however, that the process could be performed instead in reverse order (covered stent branches introduced before the endograft). 
         [0054]    Once the cuffs  124   a  and  124   b  have been inflated with a hardening agent and secured to the wall, and either before or after attachment of the endograft device  138 , the fenestrations  128   a - 128   c  are cannulated separately, and bridging small covered stents, illustrated at  146   a - 146   c  in  FIG. 6C , are deployed therein, as described above with respect to  FIGS. 5A-5C . 
         [0055]    As illustrated in  FIG. 6C , the placement of the covered stents  146   a - 146   c  through the fenestrations  128   a - 128   c  of the tubular graft  126  of the router device to create branch connections, in combination with the attachment of the endograft  138  to the distal end of the router device, creates a sealed continuous inner lumen which effectively excludes the aneurysm  122  from the circulation. 
         [0056]    While the preferred embodiments of the invention, as described above, use one or more inflatable cuffs as the attachment mechanism or arrangement for affixing the device to the interior surface of the vessel, other embodiments for the attachment mechanism are feasible. A self expanding stent arrangement, well known in the art, may be attached to the proximal end of the graft and deployed through a standard sheath introducer. Further, such a self expanding stent arrangement, in order to maintain the advantage detailed above of repositionability, may incorporate a constraining wire arrangement that allows partial deployment of the self expanding stent to a diameter less than its fully expanded state, or a diameter less than that of the adjacent aorta. By this arrangement, the graft may be repositioned prior to the removal of the constraining wire so as to best align the fenestrations  28   a - d  with the branch vessels  76   a - d . In another embodiment, the graft  26  is deployed initially in the absence of the accompanying attachment mechanism, with the proximal end  24  free floating in the arterial lumen and expanded against the adjacent wall by the pressure of the flowing blood. The attachment of graft  26  to the deployment catheter  34  is maintained through a removable binding mechanism such as a suture, such that movement and rotation of the deployment catheter  34  will still effect the desired change in position in graft  26  to optimize alignment of fenestrations  28   a - d  (or  128   a - c ) with branch vessels  76 - a - d  (or  136   a - c ). In this embodiment, the preferred sequence would then be introduction of covered stents  96   a - d  (or  146   a - c ), aiding in the fixation of the graft  26  (or  126 ) which until that point will not have undergone definitive fixation. Subsequently, an inflatable cuff element as embodied in  24  or  124  may be introduced and deployed separately, achieving such fixations. Similarly, a self expanding stent, as exists in the art, or a balloon expandable stent, as also exists in the art, may be introduced and deployed at the proximal end of graft  26  or  126  to achieve fixation. Other possible strategies for fixation of the proximal end may be possible as well. 
         [0057]    The router device of the present invention may optionally be provided with a malleable portion circumferentially surrounding each fenestration, as indicated in  FIG. 7  where the ring-shaped malleable portion  152  surrounds fenestration  154 . As described previously with regard to router device  20  of  FIG. 1  and router device  120  of  FIGS. 6A-6C , the fenestration  154  is formed in the wall  156  of the tubular graft of the router device. 
         [0058]    The malleable portion  152  is preferably constructed from a variety of synthetic plastics, such as urethane based materials, which are bioinert, but other malleable materials known in the art may be used instead. The malleable material itself may be encapsulated within an enveloping synthetic material, which, in the preferred embodiment, is composed of the same synthetic material as the tubular graft  156  (or  26  and  126  in  FIGS. 1 and 6A , respectively) itself. This limits the possibility of any fragmentation of the malleable material during the process of compression by the branch covered stent. 
         [0059]    As illustrated in  FIG. 8A , after the router device featuring tubular graft wall  156  is positioned within a tubular vessel, such as aorta  162 , a guidewire  164  is passed through a branch artery  166  and fenestration  154 . As illustrated in  FIG. 8B , a stent  168  in a collapsed condition is then passed over the guidewire  164  through branch artery  166  and into the fenestration  154 . With reference to  FIG. 8C , the stent  168  is then expanded radially so as to engage the malleable portion  152  surrounding the fenestration. As a result, the malleable portion  152  deforms to form a deformed portion  172  which is securely sealed against the exterior surface of the stent, as illustrated in  FIGS. 8C and 9 . 
         [0060]    The aortic router device and method described above therefore offers several advantages over the prior art. It allows the construction of the body of the device to be free of a metallic endoskeleton and thus conforms well to the aorta, even when there is significant tortuosity of the vessel, or angulation of the vessel segments. Second, the inflatable cuff, through use of a valve, can be inflated and deflated so that repositioning can be undertaken. Optimal positioning can be achieved before final inflation of the cuff, with a hardening agent, is performed. Flow through the aorta is maintained throughout the installation of the router device and the stents so that, even in procedures of long duration, flow is maintained to all branch vessels. The absence of the endoskeleton allows for the more easy tapering of the graft material immediately below the level of the cuff. This taper to a smaller diameter creates a slightly wider gap between the device and the branch vessel origins which permits cannulation of sidebranches, even if the alignment of the fenestration is suboptimal. The absence of the metal endoskeleton also allows the overall size of the aortic router device to be reduced, and hence there is the potential to introduce it through a smaller catheter delivery system. 
         [0061]    The router device of the present invention may be constructed in many different sizes and shapes. The only criterion which must be met is that the inflatable cuff must be of an appropriate width and diameter so that the device, branch stents and endografts are fully supported within the tubular structure by the inflatable cuff. As a result, not only can the invention be practiced in small structures, such as the vascular system, but also, the device may be affixed within much larger structures, such as the excretory system. 
         [0062]    While the preferred embodiments of the invention have been shown and described, it will be apparent to those skilled in the art that changes and modifications may be made therein without departing from the spirit of the invention, the scope of which is defined by the appended claims.