Stent anchored bifurcated vascular liner

Abstract

A device is configured to line a bifurcated vessel. The device includes a bifurcated polymeric tube with three limbs and a first stent anchor in the form of a hoop that is embedded in one of the three limbs at a location distal to the bifurcation. The limbs of the bifurcated tube are configured so that when the device is in a collapsed state, at least a portion of all three limbs and the first stent anchor are coaxial.

Description

STENT ANCHORED BIFURCATED VASCULAR LINERTECHANICAL FIELD

[0001] The invention relates to stents and liners inserted to repair iliac arteries and the aortoiliac space adjacent to the carina of bifurcation in patients suffering from aortoiliac occlusive disease (AIOD) involving the iliac arteries, aorta, or any combination of these vessels and their branches.BACKGROUND

[0002] Aorto-iliac occlusive disease (AIOD) refers to narrowing or stenosis of the blood vessels involving the infra-renal aorta and the two iliac arteries (iliacs). In many complex cases of AIOD, the aorto-iliac bifurcation is diseased. AIOD is distinct from the aneurismal disease in that the clinical problem is stenosis, not bulging of the aorta and iliacs. Peripheral arterial disease (PAD) is a circulatory issue that occurs when arteries narrow or block, reducing blood flow to the legs or arms. PAD is treated by dilation and stenting of diseased arteries. In the large arteries such as iliac arteries, stents are expected to exert significant outward force (radial force) against a calcified stenosis.

[0003] Percutaneous transluminal coronary angioplasty (PTCA) is used to increase the lumen diameter of an artery that is partially or totally obstructed by atherosclerotic plaque. In PTCA, a guiding catheter provides a safe channel from the outside to the targeted stenosis of the artery. A balloon catheter is advanced over guidewire through the guiding catheter, into the artery, and across the stenosis (crossing). The balloon is inflated to expand the narrowing. Dilatation of the occlusion, however, can form flaps, fissures and dissections which threaten abrupt reclosure or perforations of the vessel wall. To treat or prevent suchevents, tubular stents are placed within the angioplasty site to scaffold the vessel lumen. Covered stents add another layer of safety. Stenting of a bifurcation stenoses requires specialized implants and delivery equipment to achieve continuous tissue support throughout the complicated three-dimensional anatomy. A demanding example of such location is a bifurcation of the aorta where the challenge remains poorly addressed. Unfortunately, arthrosclerosis in this area is common.

[0004] Placement of covered stents in iliac arteries is the standard method of treating AIOD. The stents can be self-expanding but commonly are balloon expandable to maximize radial force and allow post dilation. The covered “kissing stents” technique and the covered endovascular reconstruction of aortic bifurcation (CERAB) technique have been developed to treat AIOD involving the aorto-iliac bifurcation. Both include simultaneous placement of two converging or “kissing” iliac stents across the bifurcation that can protrude up to 2 cm into the aorta. The covered kissing stent technique and CERAB provide a valuable degree of protection from dissection by “covering” the vessel wall from the inside with a polymer film layer (typically EPTFE fused on the stent struts). Dissection is a rare but dangerous event that occurs when a calcified vessel stenosis is “cracked” and dilated with a balloon. Junction of the aorta and iliacs is an area of high risk for dissection.

[0005] Kissing stents typically require placement of two 8F sheaths in both femoral arteries. This may be a limitation and there is a desire to eliminate one or reduce its caliber to a smaller 5-6F size. Another major shortcoming of kissing stents is the disruption of the natural blood flow through the bifurcation that can lead to uneven perfusion and thrombus formation. Another shortcoming is the need for accurate simultaneous placement of the two kissing stents. Yet another shortcoming is the high technical skill set required to perform this procedure in a way that prevents asymmetry of stents. Further yet, another shortcoming is thatthe two kissing stents make re-intervention procedures using a retrograde approach (up-and-over technique) very challenging.

[0006] Bifurcated stent grafts have the advantage of straddling the carina to preserve the natural bifurcation, avoid flow disturbances, and allow for a retrograde approach for re-intervention. However, a shortcoming to this approach is that the self-expanding stent can have insufficient outward force to maintain a patent flow lumen. Another shortcoming is the diameter of the delivery system. Yet another shortcoming is the complex procedural steps and high technical skill set that is required to place the bifurcated stent graft in the aorto-iliac bifurcation. Thus, the types of cases in which such stent grafts are used is limited.

[0007] Experts in AIOD stenting have been well aware of challenges listed above, but none of the proposed solutions can meet all the requirements.US10716690B2 to Joye “Systems and methods for deploying a luminal prosthesis over a carina” proposed the aorto-iliac stent that splits above the carina and drapes the carina but does not cover aortic walls.US20230210679A1 to Schreck “Devices and methods for treating bifurcating blood vessels” overcomes these limitations but requires stents crimped on the balloon side-by-side like shotgun barrels, which requires at least a 14F introducer, way bigger than the desired access allows.

[0008] There is a need for medical devices and methods for the treatment of AIOD involving the aorto-iliac bifurcation that will overcome the above listed shortcomings of existing methods. The medical devices and methods for the treatment of AIOD involving the aorto-iliac bifurcation described herein fulfill that need.SUMMARY

[0009] The inventors propose a novel approach to stenting of iliac arteries and the aortic segment proximal to bifurcation. The invention involves a novelstenting method and system for treating AIOD while preserving the natural anatomic aortic bifurcation.

[0010] The proposed devices meet all the key the expectations of therapy: (a) small caliber femoral access (preferably 8 - 9 F introducer), (b) high radial force in the iliac arteries, (c) protection from dissection, (d) coverage of aorta-iliac bifurcation including carina and junction on the level of carina and (e) simple deployment.

[0011] Put differently our approach has all the advantages of kissing stents while preserving the natural bifurcation and retaining radial strength and small caliber access of the kissing stents.

[0012] A principal objective of the present invention is to provide a safe and practical stenting or stent-grafting procedure; corresponding structure and delivery system to treat an aortic or other bifurcation in the vascular system of the patient, which is effective to treat occlusive disease on either side of the carina in the adjacent branch lumens without blocking or inhibiting subsequent guidewire access from an ipsilateral lumen to a contralateral lumen over the carina. The invention is primarily directed towards AIOD but is applicable to other branching vessels in high-risk areas of the body where extra protection is desired when the vessel bifurcation is stretched and stented.

[0013] The invention is described as an implantable device that is a bifurcated, stented liner and a system and a method to treat aorto-iliac bifurcation, but it is relevant to other branching arteries: e.g. aortic, coronary and cerebral arteries. Common to all locations, the liner can be a polymer film (e.g., PTFE film). It also can be a woven fabric or a fine metal wire mash. It is deployed into the branching lumen of the bifurcation of the artery and secured there by anchors prior to the treatment of the artery with high impact energy delivery devices such as shockwave therapy, high pressure balloons for dilatation and additional stenting for scaffolding. Therapy devices such as shockwave calciumfragmentation devices, a dilation balloon and a stent are deployed into the space defined by the liner with the intention to expand and scaffold the arterial stenosis. The liner remains between the arterial wall and the stent to protect the patient from dissection of the vessel wall or extrusion of plaque. The liner is made of a highly biocompatible material that promotes integration into the vessel wall and may be coated, such as heparin coated. The liner may have intentionally made holes or fenestrations to prevent trapping of blood between the liner and the blood vessel wall.

[0014] This is not the first proposal of a blood vessel liner. For example, US6383171 B1 to Gifford “Methods and devices for protecting a passageway in a body when advancing devices through the passageway” describes the use of a liner prior to stenting of an internal carotid artery. The liner is equipped with a deployment anchor on one side, upstream in relation to blood flow. When treating occlusive disease of the internal carotid artery, the anchor may be positioned completely in the internal carotid artery or may extend from the common carotid artery across the bifurcation of the internal and external carotid arteries and into the internal common carotid. The anchor preferably has an open structure which permits blood flow into the external carotid artery. Thus, Gifford specifically teaches away from lining of the bifurcation to treat the carina and bifurcation.

[0015] The liner is delivered to its implantation position in the collapsed state, as a part of a system, mounted on the delivery catheter. The collapsibility of the system is one of its main advantages since it enables smaller bore vascular access, which helps to reduce the patient’s time in the hospital and reduce complications when the patient is recovering.

[0016] The delivery system may consist of a guiding sheath, two guidewires and a delivery catheter. The catheter may be a “split shaft” catheter that is a distally bifurcated balloon catheter. The handle at the proximal end of the catheter resides outside of the body. The catheter shaft incorporates inflationlumens and guidewire lumens. Two wires may be placed (enter the shaft) in the two lumens of the proximal shaft. One wire exits distally out of the aortic branch split lumen and another wire out of the contralateral branch split lumen.

[0017] The distal end of the delivery system enters the patient’s body through the ipsilateral vascular lumen starting from a suitable access sheath inserted into a suitable femoral artery in the groin area of the patient. It is advanced through the ipsilateral lumen into the abdominal aorta above the carina and preferably below renal arteries. The catheter shaft incorporates inflation lumens and guidewire lumens.

[0018] The liner may be expanded by one or more therapeutic balloons and stents. It may be partially or fully expanded before the ultimate lumen dilation and scaffolding with a stent. The devices and methods of the present invention are particularly useful for treating occlusive disease of the aorto-iliac bifurcation because of high risks of calcification and dissection. The liner may be any suitable material including expanded PTFE (ePTFE), woven Dacron, nylon, low durometer silicone, Thermoplastic Polyurethane (TPU), or thin-walled polyethylene.

[0019] The liner is preferably mounted on a delivery catheter in a collapsed and compressed state and is advanced over a guidewire or two or more guidewires. The liner may have an anchor at least one aortic limb end which is used to open the distal aortic end of the liner in the aorta and secure or “tack” it in place to prevent it from migrating downstream urged by blood flow. The anchor may be self-expanding or balloon expandable. When installed at the aortic bifurcation, liner bifurcates to mimic roughly the inner surface of the aorta iliac bifurcation cavity. In some embodiments the liner can comprise nitinol stents with a symmetric or asymmetric Z-wave design (hoops) and one or two expanded polytetrafluoroethylene (ePTFE) membranes. Both inner and outer surfaces ofthe stent can be covered by an ePTFE membrane, and the two membranes can then be sintered together.

[0020] The liner can be elastic and stretchable to conform and cling to the curves and irregularities of the arterial wall when subjected to blood pressure. A second distal branch of the liner is placed in the contralateral iliac artery. All liner branches can be equipped with anchors that can be stents that can be apposed to the arterial wall with moderate force when expanded. When deployed, for example when the balloon is expanded, the anchors generate sufficient force to expand the liner into a tube shape with the internal lumen exposed to blood and external walls facing and circumferentially apposing the arterial wall.

[0021] Once the aortic distal end of the liner is opened and secured, the liner can be designed so that blood pressure opens the contralateral distal limb of the liner. Alternatively, or additionally, the contralateral distal limb may be snared or grasped and pulled distally. This may be needed when the disease is severe and the iliac lumen is much constricted. Alternatively, the liner may open automatically or may be opened with a separate device, the delivery catheter or the stent itself.

[0022] The liner may be an elastic liner and / or may be folded into a collapsed position. The liner may be collapsed in any suitable manner and preferably has a number of folded sections which are wrapped around one another. The folded sections can be adhered to one another to hold the liner in the collapsed position. The folded sections may be adhered together by application of heat or with an adhesive or coating. The folded liner may be loaded into an introducer sheath catheter for delivery to reduce the profile.

[0023] One inventive element of the proposed system is that, in the collapsed state for deployment, the anchoring balloons and anchors are staggered or stacked to minimize the space taken from the cross-section of the delivery catheter that needs to fit in the access sheath and cross occlusions. It isuniversally accepted among practitioners that for best practice the cross-section shall not be above 8-9 F size or that the crossing profile that is commonly defined as the maximum diameter found between the proximal end of the balloon and the distal tip of the catheter should be as low as possible and no larger than between 2 and 3 mm diameter. The profile for a liner is defined by the diameter of the shaft, the added thickness of the folded balloon, the thickness of crimped stent struts and the thickness of the folded liner itself. Such collapsed systems cannot be introduced side by side and need to be staggered in order to fit in the required diameter. The invention takes advantage of the fact that between stent rings and deployment balloons there is less material to pack and compress. When packed and compressed the delivery system alternates stent zones and liner only zones to achieve maximum utilization of volumeic space. Although this element is illustrated by examples where two or three stents are stacked in the alternating pattern, it is realized that more stents can be designed to be stacked in the compressed state his way. Since stents are essentially hoops, many more hoops can be alternated. It is also understood that balloon expandable and selfexpanding hoops can be combined and alternating without changing the essence of the invention.

[0024] When the therapeutic dilation angioplasty or stent delivery balloon is expanded within the lumen of the liner to trap the liner between the stent and the vessel. The balloon may be used to crack plaque, exert considerable radial force on the calcified plaque to increase the lumen of an iliac artery to desired caliber, which can be 8 mm for example.SUMMARY OF FIGURES

[0010] FIG. 1 illustrates a diseased aorta-iliac junction zone with two guidewires inserted therein.

[0011] FIG. 2 illustrates a liner deployed in the aorta-iliac junction zone.

[0012] FIG. 3 illustrates the liner being loaded onto the two guidewires.

[0013] FIGS. 4 illustrates the liner inside the introducer sheath.

[0014] FIGS. 5A-5D illustrate deployment of the liner inside the aorta-iliac junction zone.

[0015] FIGS. 6A-6D illustrate additional steps for the deployment of the liner inside the aorta-iliac junction zone.

[0016] FIGS. 7A-7D illustrate another configuration using self-expanding stents and a blood pressure expanded liner limb.

[0017] FIG 8 illustrates another configuration using a combination of a selfexpanding aortic stent and two balloon-expanded stents expanding iliac liner limbs.

[0018] FIG 9A illustrates the aortic self-expanding stent in the collapsed configuration

[0019] FIG 9B illustrates the aortic self-expanding stent in the released and expanded state.

[0020] FIG 10 illustrates the deployment of the contralateral limb in the combination liner.

[0021] FIG 11 is a schematic drawing of the stented bifurcated liner with multiple stacked hoops.

[0022] FIGS 12A-12D illustrate various versions of therapeutic stenting.DETAILED DESCRIPTION

[0023] Fig. 1 illustrates a patient suffering from aortoiliac occlusive disease (AIOD) manifested in the deposition of atherosclerotic plaque 10 at the level of the aortic bifurcation. Arteriosclerotic plaque 10 is seen in in the aorta 12, in the ipsilateral and contralateral iliac arteries 14, 16, at the carina 18 and at the level of the aorta-iliac junction zone 19. The patient’s first iliac artery is the Ipsilateral iliac 14 where the femoral access is established to the arterial lumens. Thesecond artery is the Contralateral iliac 16. Two guidewires 20, 22 are shown. The aortic wire 20 is threaded into the aorta. The contralateral limb wire 22 crosses over the carina 18.

[0024] Fig. 2 shows the deployed bifurcated stented liner 24. The liner 24 has three asymmetric limbs: the ipsilateral limb 26, the contralateral limb 28, and the aortic limb 30. The limbs 26, 28, 30 are terminated by stent anchors 32, 34, 36 that can be single open cell stent rings that can be self-expanding or balloon expandable rings. Although three stent anchors are shown, only the aortic anchor 32 may be necessary to prevent liner from migration under blood pressure. The limbs 26, 28, 30 may be held in place against the carina 18 and expanded by blood flow. Atherosclerotic plaque 10 is covered by the liner 24 but the lumen may not be yet restored.

[0025] Fig. 3 shows the liner 24 being loaded on the two guide wires 20, 22. Not all of the elements of the delivery system shown in order more clearly show the way the liner 24 will be advanced into the ipsilateral lumen 14 in the collapsed state and split between the aortic and the contralateral lumen 16 by following the guidewires 20, 22.

[0026] In the prior art, the bifurcated prosthesis (an EVAR device or a stent graft) is inserted with the aortic limb distal and two proximal limbs folded together proximally of the bifurcation of the graft. In our invention, the stented liner 24 is introduced over two guidewires 20, 22 with the ipsilateral iliac limb 26 loaded proximal and aortic and contralateral iliac limbs 28, 30 distal of bifurcation. In the process of the insertion, the delivery system shaft splits and the liner 24 perform a cartwheel maneuver with the contralateral limb 28 following the wire 22 into the contralateral iliac artery 16. (See Figs. 5A and 5B).

[0027] Fig. 4 shows an example of alternating stacking of the components of the liner 24 inside the introducer sheath 38. Covered stents are often constructed of individual rings of metal structure embedded or fused with thecover. Stent hoops and the cover form the tubular body comprised of a series of cylindrical hoop elements, each hoop element having a serpentine filament forming a number of proximally and distally facing crowns disposed about the circumference. Each hoop element is axially coupled to an adjacent hoop element through one or more adjoining crowns, depending on the desired balance between structural integrity and bending flexibility or not connected at all and held in place by covering. If the stent is not bifurcated these hoops neatly stack one behind another and maintain the homogeneous crossing profile even if the hoop elements that have differing pattern densities and have differing crown counts. Packing the hoops in the bifurcated stent is more challenging. If two hoops are axially matched in the compressed and packed configuration, the caliber and the crossing profile can as much as double. This is especially important with balloon mounted stents if two separate balloons are used to deploy stents in the adjacent limbs.

[0028] The example design shown in Fig. 4 shows a main shaft 40 of the delivery system that splits into the aortic limb shaft 42 and the contralateral iliac limb shaft 44 loaded into the sheath 38 stacked and offset to reduce the crossing profile of the system. The aortic wire 20 may reside in a separate removable guidewire tube 45 to prevent interference with the contralateral iliac limb balloon 46. The contralateral iliac limb shaft 44 can be equipped with a snaring mechanism to facilitate crossing of stenosis in the contralateral iliac artery 16. The ipsilateral balloon stent 50 is always loaded most proximal but distal balloons may be altered depending on anatomic requirements and disease in the patients’ lumens. The guidewire lumen for the middle balloon 54 is extended via a thin tube to allow free and unimpeded sliding of the guidewire 20 in the collapsed and loaded configuration.

[0029] Figs. 5A-5D illustrate steps for delivering the stented bifurcated liner 24 to treat the AIOD in the patient. Following standard procedure for ipsilateralfemoral artery access, the delivery system is loaded onto the two wires 20, 22, inserted into the ipsilateral lumen 14 and advanced into the aorta 12 under fluoroscopic guidance (FIG 5A). Collapsed staggered I stacked stents 48, 50, 56 crimped on balloons 46, 52, 54 are introduced inside the delivery system sheath 38 into aorta 12. The sheath 38 is retracted, and the split catheter shaft separates (FIG 5B).

[0030] The contralateral balloon 46 with the crimped stent 48 is retrieved, pulled out into contralateral iliac 16. The wire 22 may be snared and pulled out of femoral access. The shaft 44 may be snared and pulled into contralateral access. The wire 22 can be externalized through the contralateral access (FIG 5C). The crimped system is firmly sited on the carina 18 with optional snaring of the contralateral limb 28 (FIG 5D). This positive fixation by the liner 24 straddling the carina 18 may facilitate the method’s success since endovascular devices that are not immobilized can migrate under the pulsating blood pressure. The Liner System is draped over the carina 18 and is ready for deployment by the inflation of balloons.

[0031] In some embodiments, the catheter can be configured at the distal end of the contralateral split of the catheter to facilitate snaring the catheter. The catheter can be configured by the use of a hook(s), balls(s), wire end(s) or extension(s) of any geometry that facilitates the placement of a loop of the snare 58 over the distal end of the catheter. The snare can be introduced from the contralateral femoral access sheath, which can be a smaller caliber, 5 - 6F sheath to ascend antegrade through the contralateral lumen, snare the delivery catheter and pool it distally towards the contralateral access.

[0032] The step of capturing the distal end of distal shaft or stentwith intravascular snare 58 can be included in the steps of the procedure. The snare 58 is advanced from an access vessel on the contra-lateral side through contra-lateral iliac artery 16. Under fluoroscopic guidance, a snare loopor basket or other mechanism is placed over the distal end of the contralateral shaft 44. A snaring facilitating mechanism can be attached to the distal end of the distal shaft 44 to facilitate the snaring procedure. The snare loop or basket 58 is then closed over the distal end of distal shaft, the liner stent orsnaring mechanism. Figure 5D illustrates the retraction of bifurcated stented liner system into aorto-iliac bifurcation.

[0033] Figs. 6A-6D illustrate additional steps of the delivery of the stented bifurcated liner to treat the AIOD in the patient followed by dilation and stenting of stenosis. The liner fixation balloons 46, 52, 54 are in inflated and the fixation stents 48, 50, 56 are deployed sequentially or at the same time (FIG 6A). The liner 24 is deployed and balloons 46, 52, 54 are deflated (FIG 6B). The liner delivery catheter is withdrawn (FIG 6C). The stent delivery catheter 60 is introduced to deliver the stents 62 inside the liner 24 protected from dissection and plaque extrusion (FIG 6D). The stents 62 deployed inside the liner 24 can be bare metal or covered, balloon expandable or self-expanding and cover iliac arteries and aorta.

[0034] Figs. 7A-7D illustrate an alternative configuration using selfexpanding stents and a blood pressure expanded liner limb. Wires 20. 22 are placed using traditional bilateral femoral access. For example, 8F access in the ipsilateral 14 and a smaller 5F contralateral sheath 64. The wires 20, 22 are loaded through: (1) the ipsilateral limb 26 to the aorta limb 30, (2) the ipsilateral limb 26 to the contralateral limb 28. The liner 24 is folded inside the sheath 64 and advanced over the wires 20, 22 to the aortic position above carina 18 (e.g.10 to 20 mm). Using a snare 66 introduced from the contralateral access the contralateral wire 22 is pulled and externalized at the femoral access. The liner 24 is equipped with self-expanding fixation stents. First, the aortic ring 68 is deployed. The liner 24 is filled with blood under aortic pressure which forces it to conform and comply to the contours of the lumen. The sheath 64 is withdrawnand aortic retaining ring 68 (nitinol self-expanding stent fused to the liner 24) is deployed securing proximal location of the liner 24 and sealing the liner 24 to the aortic wall. The liner 24 is inflated by pressurized blood flow. The sheath 64 is withdrawn further distally into the ipsilateral iliac 14. The contralateral “windsock” limb 28 of the liner 24 is released and inflated by blood pressure conforming to the iliac artery 16 and forming a lumen. The contralateral limb 28 can be equipped with a grasping element that can be snared by the snare 66 introduced over the contralateral wire 22 to assist in pulling the limb 28 into the contralateral iliac lumen 16 through the stenosis. The sheath 64 is withdrawn further distally into the ipsilateral iliac 14. The distal ipsilateral retaining stent 70 is released completing the liner lumen 24 and securing the passage for exchange and stent deployment.

[0035] Fig. 8 illustrates another configuration using a combination of a selfexpanding aortic stent 72 and two balloon-expanded stents 74, 76 expanding iliac liner limbs 26, 28.

[0036] The aortic limb 30 is terminated in a self-expanding fixation ring 72. Ipsilateral and contralateral limbs 26, 28 are mounted on balloons and are balloon expandable. The contralateral limb 28 is equipped with a pull out element 82 that can be snared with the contralateral access snare.

[0037] The aortic stent 72 is covered by the cap 84 that prevents it from expanding until the cap 84 is pushed distally by the pushrod 86 that traverses the shaft 88 and operated by the handle outside of the body.

[0038] Figs. 9A and 9B detail the aortic self-expanding stent 72 in the collapsed configuration (9A) and released and expanded in the aorta (9B). The aortic stent 72 is covered by and compressed under the cap 84 that prevents it from expanding until the cap 84 is pushed distally by the pushrod 86 that traverses the shaft 88 and operated by the handle outside of the body. After positioning in the aorta 12, the pushrod 86 is activated, and the stent 72 isexpanded occluding blood flow in the aorta 12. The liner 24 is expanded by the pressure of aortic blood.

[0039] Fig. 10 illustrates the deployment of the contralateral limb 28 in the combination liner. The contralateral limb 28 is snared while in the collapsed state with the liner 24 attached to the stent 74, folded and crimped on the balloon 78. After the liner 24 is positioned, the balloon 78 is inflated and the fixation stent 74 is deployed. The deployment of the ipsilateral stent 76 follows after further retraction of the sheath 88.

[0040] Fig. 11 illustrates the schematic of the stented bifurcated liner with multiple stacked hoops 90. The terminal hoop 74 on the contralateral limb 28 is equipped with a grasping element 92 to facilitate snaring and pulling of the limb 28.

[0041] Figs. 12A-12D Illustrate various versions of therapeutic stenting with balloon dilation after the liner 24 is placed. Therapeutic stents 94 are inserted inside the liner 24. The therapeutic stents 94 may protrude outside the liner 24 and overlap with a stent anchor 72, 74, 76 that is configured to expand the liner 24 and further prevent the liner 24 from migration. The stents 94 may be covered or bare metal or partially covered. The stents 94 can be balloon expandable or self-expanding. The stents may be post dilated and flared to form the irregular shape at the bifurcation. The liner lined lumen is stented as an extra degree of safety.

[0042] Fig. 12A illustrates a configuration in which two “kissing” stents 94 are placed using traditional methods using bilateral femoral access and inflated simultaneously by operator.

[0043] Fig. 12B illustrates a configuration in which a saddle type cross-over stent 94 is placed using ipsilateral access. The wire 96 may be snared from the contralateral side. Balloons 98, 100 are shown on the same shaft 102 and share inflation lumen.

[0044] As illustrated in Fig. 12C, after the iliac stents 94 are placed, the aortic stent 94 is placed using an exchanged balloon catheter.

[0045] As can be seen in Fig. 12D, once fully inflated, the “kissing’’ stents 94 are protruding into the aorta 12.

[0046] While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms “comprise” or "comprising" do not exclude other elements or steps, the terms "a" or "one" do not exclude a plural number, and the term “or” means either or both, unless this application states otherwise. Also, the terms “approximately” and “substantially” encompass a range of plus or minus 15%. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise.EMBODIMENTS

[0047] The following is a non-limiting list of exemplary embodiments according to the present disclosure.

[0048] Embodiment 1. A method of loading and implanting an expandable bifurcated stented liner having an aortic limb, a contralateral iliac limb and an ipsilateral iliac limb into an aortic bifurcation of a patient having an ipsilateral iliac artery, a contralateral iliac artery and an aorta, the method comprising steps of: threading a first wire through the ipsilateral iliac limb and the aortic limb of the stented liner and into the patient’s aorta; threading a second wire through the ipsilateral iliac limb and contralateral iliac limb of the stented liner and into the contralateral iliac artery; advancing the stented liner over the first and second wires in a collapsed state until the contralateral limb is in thecontralateral iliac artery and the aortic limb is in the aorta and the stented liner is draped over the patient’s carina.

[0049] Embodiment 2. The method of embodiment 1, further comprising a step of snaring the contralateral limb of the liner and dragging it into the contralateral iliac artery until the liner is draped over the patient’s carina.

[0050] Embodiment 3. The method of any one of the preceding embodiments, further comprising expanding an anchor stent attached to the stent liner to expand a lumen of the stent liner and urge the lumen of the stent liner into the contact with blood vessel walls.

[0051] Embodiment 4. The method of any one of the preceding embodiments, further comprising dilating and stenting a narrowed region of the patient’s vessel.

[0052] Embodiment 5. A method of mitigating a dissection in a bifurcated blood vessel while dilating a narrowed region of the vessel, the method comprising the steps of: providing a liner deployable from a collapsed condition to an expanded condition; advancing the liner to an aortic bifurcation while the liner is in the collapsed condition so that one limb of the liner is advanced into the contralateral iliac artery, the liner is draped over the patient’s carina, and at least a portion of the liner is advanced into the patient’s contralateral iliac artery; advancing a dilation stent through the inside of the liner after the liner has been positioned within the patient’s ipsilateral iliac artery, the patient’s aorta, and the patient’s contralateral iliac artery, the dilation stent being advanced to a narrowed region of one of the patient’s ipsilateral iliac artery, the liner intervening between the dilation stent and the corresponding vessel; and expanding the dilation stent so that the dilation stent expands the liner and the narrowed region of the corresponding blood vessel simultaneously.

[0053] Embodiment 6. The method of embodiment 5, further comprising: advancing one or more additional dilation stents through the inside of the linerafter the liner has been positioned within the patient’s ipsilateral iliac artery, the patient’s aorta, and the patient’s contralateral iliac artery, the dilation stent being advanced to other narrowed regions of the bifurcated vessel; and expanding the one or more dilation stents so that the one or more dilation stent expand the liner and the narrowed region of the corresponding blood vessel simultaneously.

[0054] Embodiment 7. The method of any one of embodiments 5 to 6, wherein at least one end of the liner is expanded before the dilation stent is expanded.

[0055] Embodiment s. The method of any one of embodiments 5 to 7, wherein the distal and proximal ends of the liner are expanded and anchored by anchoring stents that are fixed to the distal and proximal ends of the liner.

[0056] Embodiment 9. The method of Embodiment 8, wherein the anchoring stents are closed cell stents.

[0057] Embodiment 10. The method of embodiment 9, wherein the anchoring stents are open cell stents.

[0058] Embodiment 11. The method of any one of embodiments 8 to 10, wherein the anchoring stents are comprised of zigzag hoops.

[0059] Embodiment 12. The method of any one of embodiments 8 to 11, wherein the anchoring stents are self-expanding.

[0060] Embodiment 13. The method of any one of embodiments 8 to 12, wherein the anchoring stents are balloon expandable.

[0061] Embodiment 14. The method of any one of embodiments 8 to 13, wherein the liner and the anchoring stents are advanced through the limbs in the collapsed state.

[0062] Embodiment 15. The method of any one of embodiments 8 to 14, wherein the anchoring stents and the liner are delivered to the bifurcated blood vessel through a bifurcated shaft.

[0063] Embodiment 16. The method of embodiment 15, wherein the bifurcated shaft is contained within a sheath.

[0064] Embodiment 17. The method of embodiment 16, wherein a distal end of the sheath is enclosed by a push cap.

[0065] Embodiment 18. The method of embodiment 17, wherein the push cap constrains one of the anchor stents.

[0066] Embodiment 19. The method of any one of embodiment 17 to 18, further comprising advancing a pushrod attached to the push cap to advance the push cap and release the anchor stent.

[0067] Embodiment 20. The method of embodiment 19, wherein the release of the anchor stent leads to the deployment, circumferential expansion and at least partial inflation of the liner by way of the flow of blood.

[0068] Embodiment 21. The method of any one of embodiments 8 to 20, wherein an anchor stent in the contralateral limb includes a snaring arrangement, element or attachment.

[0069] Embodiment 22. The method of any one of embodiments 8 to 21, wherein the anchoring stents are held in a collapsed position while being advanced through the blood vessels, and wherein the anchoring stents are expanded in the iliac artery and / or aorta so that the anchoring stent moves into contact with the vessel wall so that the liner naturally drapes or straddles over the patient’s carina.

[0070] Embodiment 23. The method of any one of embodiments 5 to 22, further comprising sequentially or simultaneously expanding the ipsilateral and contralateral iliac arteries by sequentially or simultaneously expanding therapeutic stents.

[0071] Embodiment 24. The method of any one of embodiments 5 to 23, wherein the bifurcated liner is advanced through the aortic bifurcation prior to advancing the dilation stent.

[0072] Embodiment 25. The method of any one of embodiments 5 to 24, wherein to stenosed arteries are simultaneously dilated by simultaneously dilating two therapeutic stents.

[0073] Embodiment 26. The method of embodiment 25, wherein the two therapeutic stents are mounted on the same shaft and share the same balloon inflation lumen.

[0074] Embodiment 27. The method of embodiment 25, wherein the two therapeutic stents are mounted on separate shafts and inflated via separate balloon inflation lumens.

[0075] Embodiment 28. The method of any one of embodiments 5 to 24, wherein the dilating stents are bare metal or covered stents implanted at least partially inside of the liner.

[0076] Embodiment 29. The method of any one of embodiments 5 to 25, wherein the liner is delivered by a delivery catheter, and the liner extends from a distal end of the delivery catheter.

[0077] Embodiment 30. The method of embodiment 29, wherein the liner is folded within the delivery catheter so that two limbs face the distal end of the delivery catheter from the bifurcation of the liner and one limb faces toward the proximal end of the delivery catheter from the bifurcation of the liner.

[0078] Embodiment 31. The method of any one of claims 24 to 47, wherein the liner is advance over a guidewire.

[0079] Embodiment 32. A method of opening a narrowed region in a bifurcated blood vessel, the method comprising the steps of: providing a liner able to transition from a collapsed condition to an expanded condition, the liner having at least one an expandable anchor coupled to the liner; advancing the liner to a narrowed region of a blood vessel with the liner in the collapsed position; passing at least a portion of the liner into the narrowed region of the blood vessel in the collapsed position; expanding the anchor with a balloon,where the narrowed region can be a contralateral or an ipsilateral iliac artery; positioning a dilation stent inside the liner after the liner has been expanded in the narrowed portion of treated vessel so that the stent is also positioned in the narrowed region of the blood vessel, the liner preventing the stent from contacting the narrowed region of the blood vessel; and expanding the stent so that the stent expands the liner and the narrowed region of the blood vessel simultaneously with a radial force capable of dilating the narrowed vessel.

[0080] Embodiment 33. The method of embodiment 32, wherein the bifurcated blood vessel is an aorta.

[0081] Embodiment 34. The method of embodiment 33, wherein limbs of the liner are advanced into the aorta and the iliac arteries, and the liner is draped over the patient’s carina.REFERENCES TO THE DRAWINGS10 Plaque12 Aorta14 Ipsilateral iliac artery16 Contralateral iliac artery18 Carina19 Aorta-iliac junction zone20 Aortic guidewire22 Contralateral guidewire24 Liner26 Ipsilateral iliac limb28 Contralateral iliac limb30 Aortic limb32 Aortic anchorIpsilateral iliac anchor Contralateral iliac anchor Introducer sheathMain shaftAortic limb shaftContralateral iliac limb shaft Aortic Guidewire tube Contralateral iliac limb balloon Contralateral iliac limb balloon stent Ipsilateral iliac limb balloon stent Ipsilateral iliac limb balloon Middle / aortic balloonAortic balloon stentSnareCatheterStentSheathSnareAortic ringIpsilateral iliac retaining stent Fixation ringFixation ringFixation ringBalloonBalloonPullout elementCapPushrodShaftHoopGrasping element StentWireBalloonBalloonShaft

Claims

CLAIMS1. A device configured to line a bifurcated vessel, the device comprising: a bifurcated polymeric tube with three limbs; anda first stent anchor in the form of a hoop that is embedded in one of the three limbs at a location distal to the bifurcation,wherein the limbs of the bifurcated tube are configured so that when the device is in a collapsed state, at least a portion of all three limbs and the first stent anchor are coaxial.

2. The device of claim 1, further comprising a second stent anchor in the form of a hoop that is embedded in another one of the three limbs of the bifurcated tube at a location distal to the bifurcation,3. The device of claim 2, further comprising a third stent anchor in the form of a hoop and each of the stent anchors is embedded in a different limb of the bifurcated polymeric tube so that each limb of the bifurcated polymeric tube has a corresponding stent anchor embedded therein at a location distal to the bifurcation.

4. The device of any one of claims 1 to 3, wherein the limbs of the bifurcated tube are configured so that when in the collapsed state, all of the stent anchors are coaxial and spaced in such a way that the stent anchors do not overlap.

5. The device of any one of claims 2 to 4, wherein when the bifurcated polymeric tube is in the collapsed state, portions of two of the limbs of the bifurcated polymeric tube are positioned radially side-by-side and the stentanchors embedded within the two limbs are axially stacked in an alternating pattern.

6. The device of any one of claims 1 to 5, wherein none of the limbs of the bifurcated tubes have more than one stent anchor embedded therein.

7. The device of any one of claims 1 to 6, wherein the walls of the limbs of the bifurcated polymeric tube have holes or fenestrations positioned to prevent the trapping of blood between the bifurcated polymeric tube and the walls of the bifurcated vessel.

8. The device of any one of claims 1 to 7, further comprising a sheath that is configured to maintain the bifurcated polymeric tube in the collapsed state, the bifurcated polymeric tube being removable from the sheath through an open end of the sheath.

9. The device of any one of claims 1 to 8, wherein the bifurcated polymeric tube comprises one or more membranes made of polytetrafluoroethylene (ePTFE) that are sintered, sewn, or otherwise attached circumferentially to the stent anchors.

10. The device of any one of claims 1 to 9, wherein each of the stent anchors is made of nitinol.

11. The device of any one of claims 1 to 10, wherein the length of one of the limbs of the bifurcated polymeric tube is shorter than the length of the other two limbs.

12. The device of any one of claims 1 to 11, wherein each of the limbs of the bifurcated polymeric tube has a different length.

13. A system for delivering and implanting an expandable bifurcated stented liner, the system comprising:a delivery catheter;a bifurcated liner membrane with an aortic limb, a contralateral iliac limb, and an ipsilateral iliac limb, the bifurcated liner membrane being removably contained within the delivery catheter;a first anchor stent attached to the aortic limb;a second anchor stent attached to the contralateral iliac limb; and a third anchor stent attached to the ipsilateral iliac limb;wherein the bifurcated liner membrane is configured so that when the bifurcated liner membrane is positioned within the delivery catheter, the aortic limb and the contralateral iliac limb are folded so that their distal ends are distal to the ipsilateral limb, andwherein the first, second and third anchor stents are stacked along the catheter in an axially alternating pattern.

14. The system of claim 13, further comprising an aortic balloon attached to the aortic limb, wherein the first anchor stent is crimped onto the aortic balloon.

15. The system of claim 14, further comprising a contralateral iliac balloon attached to the contralateral iliac limb, wherein the second anchor stent is crimped onto the contralateral iliac balloon.

16. The system of any one of claims 14 to 15, further comprising an ipsilateral iliac balloon attached to the ipsilateral iliac limb, wherein a third anchor stent is crimped onto the third balloon.

17. The system of any one of claims 13 to 16, further comprising a bifurcated shaft that contains the bifurcated liner membrane.

18. The system of claim 17, wherein the distal end of the bifurcated shaft is split into two legs so that the aortic limb of the bifurcated liner membrane is located in a first leg of the bifurcated shaft and the contralateral iliac limb of the bifurcated liner membrane is located in a second leg of the bifurcated shaft.

19. The system of any one of claims 17 and 18, further comprising two guidewire lumens that extend from that proximal end of the bifurcated shaft to the distal end of the bifurcated shaft, a first one of the guidewire lumens extending through the first leg of the bifurcated shaft and a second one of the guidewire lumens extending through the second leg of the bifurcated shaft.

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