A magnet assisted surgical device, system, and method employs magnetic sections, catheters, and guidewires to modify tubular stentgrafts in-situ. One example application provides a more reliable way for surgeons to modify stentgrafts insitu to allow blood flow to continue to branching blood vessels that would otherwise be blocked by the stentgraft itself. One such method includes placing a tip section of the device in the desired location, deploying a stentgraft, placing a magnetic device inside the stentgraft, connecting the magnetic device to the tip section, and excising the portion of the stentgraft held between the magnet and the tip section.

FIELD OF THE DISCLOSURE

The instant disclosure relates to the use of magnetism to assist in the in-situ fenestration of a tubular stentgraft.

BACKGROUND

An aortic aneurysm refers to the expanding or ballooning of the aorta, the major artery that delivers blood from the heart to the rest of the body. This expansion can result from various genetic conditions, diseases, or some underlying weakness in the wall of the aorta, often as a result of buildup of artheriosclerotic plaque. These aneurysms usually do not initially produce symptoms, however further enlargement can result in pain, numbness, embolism, or rupture often resulting in death. Over ten thousand deaths each year are directly attributable to aortic aneurysms in the United States.

Aneurysms may be treated with the prescription of beta blockers, cessation of smoking, or conventional blood pressure regulation methods, among other treatments. These measures merely slow the growth of the aneurysm, but generally do not totally stop expansion. When the risks associated with surgery are outweighed by the risk of rupture, aortic aneurysms are treated via surgery. Surgical options for the treatment of an aortic aneurysm include traditional open procedures and endovascular therapy. Open surgery involves replacing the affected portion of the aorta with a synthetic graft. Often times, open surgery becomes the only repair option due to various anatomic and patient related factors. However, open surgery of the aorta can have significant physiologic impact which for some patients becomes beyond the threshold of tolerance.

As an alternative to open surgery, endovascular therapy involves the placement of an endovascular stent in the aneurysm. This procedure involves the insertion of the stent into the femoral artery through an incision in the patient's thigh, and from there, into the aorta. The less invasive nature of endovascular therapy results in a reduced physiological impact when compared to open surgery. Generally, the stents used for this procedure are generalized, off-the-shelf products that can be implemented in a standard aortic aneurysm. However, when the aneurysm exists at or near a point in the aorta where a branching artery connects to the aorta, a standard stent is generally not feasible because the stent, in circumventing the aneurysm also circumvents the branch artery as well.

Current solutions for this issue include custom endografts based on precise measurements obtained from CT imaging. These custom endografts generally take weeks to be manufactured and therefore are not a viable option for urgent or emergent cases. Another solution currently available to surgeons is to modify the endograft themselves prior to implantation based on similar precise CT imaging. This process can be difficult and oftentimes imprecise in practice, thus leading to challenges when the modified endograft is introduced. Further, another options available to solve this issue involves the use of chimney, periscope, snorkel, and sandwich graft techniques, commonly referred to as “CHIMPS.” This option involves the use of a variety of prefabricated grafts that include additional portions that may be used to route blood to the branch arteries. Although these techniques can achieve repair, they provide less structural stability and can be prone to failure. These problems underscore the need for a fast, reliable method of modifying stents in-situ.

SUMMARY

The present invention is directed to apparatus, methods, and systems for magnetic assisted in-situ fenestration of tubular stentgrafts. Using the apparatuses described herein, a physician who is treating a patient diagnosed with an abdominal aortic aneurysm may insert a magnetic tip section into an artery branching off from the affected artery, inset a stentgraft into the affected artery, insert a magnetic docking section into the stentgraft causing the two magnetic sections to connect, and excise the portion of the stentgraft held between the two magnets thus allowing blood to flow from the affected artery into the branch artery despite the presence of a stentgraft that would otherwise be blocking the branch artery. The in-situ nature may allow for valuable time to be saved without the need for complex, precise CT measurements.

In one embodiment, the fenestration device includes a tip section with two ends and two guidewires. The tip section may be magnetic, with one guidewire running through the tip section from one end to the opposite end, and with the other guidewire attached to the tip section. The tip section may be ogive-shaped, and may comprise neodymium, cobalt, iron, samarium, cobalt, copper, zirconium, alnico, ferrite, or some combination thereof. The guidewires may have a diameter between 0.021 inches and 0.038 inches, or a diameter between 0.014 inches and 0.021 inches. In certain embodiments there may be two catheters, one of which fits around one of the guidewires while the other catheter fits around the other guidewire.

In another embodiment, the fenestration device includes a tip section, a docking section, and a guidewire attached to the tip section. Both the tip section and the docking section have a proximal and a distal end. Further, the tip section has a magnetic distal end, while the docking section has a magnetic proximal end such that the distal end of the tip section and the proximal end of the docking section can be magnetically docked. A catheter may be attached to the distal end of the docking section. Further, the guidewire used may be between 0.014 inches and 0.038 inches. Additionally, a second guidewire may run through both the tip section and the docking section.

Another embodiment of the invention is a system including a tip section with a magnetic distal end, a docking section with a magnetic proximal end, three guidewires, and two catheters. The tip section slidably receives the first guidewire, allowing the first guidewire to run through its central axis. Further, the tip section attaches to the second guidewire, detachably connects to the first catheter, magnetically docks with the proximal end of the docking section which is connected to the second catheter, and slidably receives the third guidewire, allowing the third guidewire to run through its central axis. An electric hot-wire loop may be included that surrounds and is guided by the second catheter, travels along the second catheter up to the docking section, and excises a round section from the material sandwiched between the tip section and the docking section. Further, the tip section may be ogive-shaped; the tip section and the docking section may be made out of neodymium, cobalt, iron, samarium, cobalt, copper, zirconium, alnico, ferrite, or some combination thereof; the guidewires may have a diameter of between 0.021 inches and 0.038 inches or between 0.014 inches and 0.021 inches; or the second guidewire may be attached to the side of the tip section.

Another embodiment of the invention is a method for the in-situ fenestration of tubular stentgrafts through the use of a magnetically assisted fenestration device. The method includes several steps. First, a magnetic tip section is placed into a vessel that branches off of a main vessel. Next, a stentgraft is deployed into the main vessel so the branching vessel is blocked by the stent. A magnetic docking section is then placed inside of the stentgraft. Next, the magnetic tip section is pulled towards the stentgraft enabling it and the magnetic docking station to magnetically dock. The two docked sections are then used as a guide to navigate a fenestration element to the stentgraft where the fenestration element then excises a portion of the stentgraft.

DETAILED DESCRIPTION

FIG. 1is an illustration showing a tip section of a fenestration device configured to aid in the in-situ fenestration of tubular stentgrafts according to one embodiment of the disclosure. An in-situ fenestration device may include a guidewire102that enters the proximal end104of the tip section120and runs through the body of a tip section120of the fenestration device. The guidewire102is fed into the vessel where the physician desires to place the tip section120and is used to guide the tip section120into said vessel. The tip section120may comprise a plurality of sub-sections122,124,126. The portion122may be made of soft material similar to current catheters to not injury the artery it is being advanced into the artery. The portion122may be used to guide a dilator similar to that of a sheath of conventional stents. The portion124may serve as the junction between the portions122and126. A second guidewire106may be mounted to the tip section120, and may be affixed to any part of the tip section120. The second guidewire106may be used, once the tip section120is in place, to pull the tip section120back out its initial placing. One embodiment is shown inFIG. 1wherein the guidewire106is attached to the side of the tip section120. The guidewire102may exit the tip section120at the distal end108.

The in-situ fenestration device may include additional elements such as catheters to aid in the insertion of guidewires into a patient.FIG. 2is an illustration showing a tip section of one such fenestration device configured to aid in the in-situ fenestration of tubular stentgrafts according to one embodiment of the disclosure. In this embodiment, the fenestration device may include a catheter202which is detachably connected to the tip section120. The catheter202is used by the physician to help guide the tip section120along the guidewire102so that the tip section can be initially placed in the desired location.

The tip section120, in order to be positioned in the desired location, may be detachable from the catheter(s) themselves. For example,FIG. 3is an illustration showing a tip section of a fenestration device configured to aid in the in-situ fenestration of tubular stentgrafts according to one embodiment of the disclosure wherein, the tip section120is shown detached from the catheter portion202of the device. The detachment of the catheter allows for the tip section120, once in the desired location to be left there, while the catheter202is then removed from the patient.

Further, the tip section120and any accompanying catheters may allow for guidewires to pass coaxially through them. For example,FIG. 4is an illustration showing a tip section of a fenestration device configured to aid in the in-situ fenestration of tubular stentgrafts according to one embodiment of the disclosure in which the tip section120may have having a proximal end104and a distal end108. A tubular lumen402may extend through the tip section120from the proximal end104to the distal end108. The tubular lumen402would allow for guidewires to be passed coaxially through the tip section120and any attached catheters. Two coaxial catheters404,202may be detachably connected to the distal end108of the tip section120of the fenestration device. The smaller catheter404may be either independent from or attached to the larger catheter202. These catheters404,202allow for a guidewire102to be passed through up the catheters404,202and the tip section120in order to aid the physician in placing the tip section120into the desired location before detaching the catheters and removing them from the patient. The catheters404(and catheter706described below) ay be sized such that their lumen is completely occluded by the guide wire, such as sizes of 0.035 or 0.038.

The present invention may include features that provided flexibility and options to physicians when practicing the disclosed fenestration device. For example,FIG. 5is an illustration showing a tip section120configured so that it may be detached from a catheter202. The proximal end of the detached catheter502, and the catheter itself202, may still surround the coaxial inner catheter404. In this depiction of an embodiment, the inner catheter404may still be detachably connected to the distal end108of the tip section120of the fenestration device. The independent detachability may allow physicians more options to handle their patient's individual needs or more effectively respond to situations that arise during the procedure.

Each element of the apparatus may be independent from each other element, while simultaneously allowing for them to interact, connect to, or be guided by other elements. For example,FIG. 6is an illustration showing a tip section120according to one embodiment of the disclosure that has been detached from both the proximal end of the inner catheter602and the proximal end of the outer catheter502. Therefore, the inner catheter404and the outer catheter202may both be independent and detachable from the tip section120of the fenestration device.

In reference to the guidewires, in one embodiment of the disclosure, the first guidewire102may have a diameter of 0.035 inches (0.89 mm), but in other embodiments the first guidewire102may have a diameter of 0.014 inches (0.36 mm), 0.018 inches (0.46 mm), 0.021 inches (0.53 mm), 0.025 inches (0.64 mm), 0.032 inches (0.81 mm), or 0.038 inches (0.97 mm). Further, in one embodiment of the disclosure, the second guidewire106may have a diameter of 0.014 inches (0.36 mm), but in other embodiments the second guidewire106may have a diameter of 0.018 inches (0.46 mm), 0.021 inches (0.53 mm), 0.025 inches (0.64 mm), 0.032 inches (0.81 mm), 0.035 inches (0.89 mm), or 0.038 inches (0.97 mm). Because all guidewire sizes are viable, all suitable guidewires are contemplated and the choice of which to use depends on the specific patient being treated and the specifics of that patient's condition.

With regards to the tip section120, the first guidewire102runs coaxially through the tubular lumen402of the tip section120. In this embodiment, the first guidewire102is not connected to the tip section120, thus allowing the tip section to slide freely along the guidewire102. Also according to this embodiment, the second guidewire106is permanently affixed to the side of the tip section120. The second guidewire106may be attached at such an angle to easily allow for the second guidewire to extend distally along the same path as the first guidewire102, large catheter202, and small catheter404. In one embodiment, the second guidewire106is attached to the tip section via vibration welding. However, all suitable methods of attachment are contemplated. For example, in one embodiment of the disclosure, the second guidewire106is attached by inserting the guidewire106into a channel on the tip section and kinking the guidewire106such that the guidewire106cannot be removed from the tip section120when force is applied to either. In yet another embodiment, the guidewire106may be glued to the tip section120.

The distal end108may be magnetic. The tip section120might not be a homogeneous material, but instead may have the distal end108alone made of a magnetic material. Alternatively, the tip section120as a whole may be magnetic and thus may be made of a single material. In one embodiment, the magnetic portion of the tip section120is comprised of one or more rare earth metals. One skilled in the art would understand rare earth metals to identify a type of strong permanent magnets made from combinations or alloys of rare earth elements. Such rare earth elements include, but are not limited to Scandium (Sc), Yttrium (Y), Lanthanum (La), Cerium (Ce), Praseodymium (Pr), Neodymium (Nd), Promethium (Pm), Samarium (Sm), Europium (Eu), Gadolinium (Gd), Terbium (Tb), Dysprosium (Dy), Holmium (Ho), Erbium (Er), Thulium (Tm), Ytterbium (Yb), and Lutetium (Lu). Additionally, one skilled in the art would understand that in addition to these rare earth elements, rare earth magnets may comprise additional elements including, but not limited to, Iron (Fe), Nickel (Ni), Cobalt (Co), Aluminum (Al), Copper (Cu), Titanium (Ti), and Boron (B). These magnetic characteristics may allow the tip section120to further interact and magnetically dock with other portions.

The tip section may be ogive-shaped. A person having ordinary skill in the art would understand the description “ogive” to refer to an object having a roundly tapered end. For example, the tip section120of the device is in the shape of a bullet. This shape allows the bullet to more easily pass within vessels by reducing the risk of the vessels being damaged. Additionally, the tip section120may include a tubular lumen402running coaxially from its proximal end104to its distal end108. The tubular lumen402may have a diameter of 0.035 inches, but may alternatively have a diameter of 0.014 inches (0.36 mm), 0.018 inches (0.46 mm), 0.021 inches (0.53 mm), 0.025 inches (0.64 mm), 0.032 inches (0.81 mm), or 0.038 inches (0.97 mm) to fit the various guidewire sizes that may be used in conjunction with the tip section120.

In reference to the catheters, the small catheter404may run coaxially with the larger catheter202. Both the small catheter404and the larger catheter202may be detachably connected from the tip section120. The size of the larger catheter202(and larger catheter708shown below) may be dependent upon the diameter of the magnets that are selected and based on a diameter of the vessel being cannulated. In one embodiment, the small catheter404is French gauge4catheter, but in other embodiments the small catheter404may be French gauge3,5,6, or7. Because all catheter sizes are viable, all suitable catheters are contemplated and the choice of which to use depends on the size guidewires being used, the specific patient being treated, and the specifics of that patient's condition.

In addition to the tip section120, the apparatus may include a complementary docking section that magnetically interacts with the tip section. These two sections, when acting together, may be used to isolate a portion of the stentgraft such that the portion may be excised.

FIG. 7is an illustration showing a docking section of a fenestration device configured to aid in the in-situ fenestration of tubular stentgrafts according to one embodiment of the disclosure. A docking section704is connected to two coaxial catheters: a large catheter708and a smaller catheter706. The lumen of the smaller catheter continues through the tubular lumen702that runs through the docking section704such that a guidewire may coaxially run thought both the docking section704and the catheters706,708. The large catheter708connects to the docking station and surrounds the smaller catheter706.

As with the tip section120, the docking section704may be magnetic. In one embodiment, the docking section704is comprised of one or a combination of rare earth metals. One skilled in the art would understand rare earth metals to identify a type of strong permanent magnets made from combinations or alloys of rare earth elements. Such rare earth elements include, but are not limited to Scandium (Sc), Yttrium (Y), Lanthanum (La), Cerium (Ce), Praseodymium (Pr), Neodymium (Nd), Promethium (Pm), Samarium (Sm), Europium (Eu), Gadolinium (Gd), Terbium (Tb), Dysprosium (Dy), Holmium (Ho), Erbium (Er), Thulium (Tm), Ytterbium (Yb), and Lutetium (Lu). Additionally, one skilled in the art would understand that in addition to these rare earth elements, rare earth magnets may comprise additional elements including, but not limited to, Iron (Fe), Nickel (Ni), Cobalt (Co), Aluminum (Al), Copper (Cu), Titanium (Ti), and Boron (B). These magnetic characteristics allow the docking section to further magnetically interact with a tip section120.

The docking section704may have a cylindrical shape and connect with catheters706,708on one of the two flat cylinder faces. The docking section704may additionally have a tubular lumen702that runs from one cylinder face to the opposite face in order to allow guidewires to be passed through it. In one embodiment, the tubular lumen702has a diameter of 0.035 inches, but may alternatively have a diameter of 0.014 inches (0.36 mm), 0.018 inches (0.46 mm), 0.021 inches (0.53 mm), 0.025 inches (0.64 mm), 0.032 inches (0.81 mm), or 0.038 inches (0.97 mm) to fit the various guidewire sizes that may be used in conjunction with the docking section704.

In reference to the catheters that could be used in connection with a docking section704, in one embodiment, the small catheter706runs coaxially with the larger catheter708. Both the small catheter706and the larger catheter708may be permanently attached to the docking section704. In one embodiment, the small catheter706is French gauge4catheter, but in other embodiments the small catheter706may be French gauge3,5,6,7, or8. Because all catheter sizes are viable, all suitable catheters are contemplated and the choice of which to use depends on the size guidewires being used, the specific patient being treated, and the specifics of that patient's condition.

The apparatus may additionally include an element that has the capability of excising a portion of the surgical stentgrafts used by the physician to treat an aneurysm.FIG. 8in an illustration showing an electric hot-wire loop section of a fenestration device configured to aid in the in-situ fenestration of tubular stentgrafts according to one embodiment of the disclosure. The fenestration portion of the electric hot-wire loop802may be located at the proximal end of the body of the fenestration section804. The electric hot-wire loop section of the fenestration device creates heat for the purpose of cutting material by applying an electrical current across an exposed wire loop802thereby causing the wire loop802to generate heat. The current necessary to cause the fenestration portion of the electric hot-wire loop802to be used as a cutting implement is fed to the loop802through wires running up the body of the fenestration section804. The loop form of the fenestration portion802allows for a guidewire or catheter to run through the loop and thus guide the loop to a desired location.

The electric hot-wire loop and the docking section may be configured to interact with one another.FIG. 9is an illustration showing an embodiment of such an interaction configured to aid in the in-situ fenestration of tubular stentgrafts. A fenestration portion of an electric hot-wire loop802surrounds and is guided by a catheter708attached to a docking section704of the device. The body of the fenestration section804extends distally, approximately parallel to the catheter708. In one embodiment, the fenestration portion of the electric hot-wire loop802may be larger in diameter than the outer diameter of the catheter708so that the hot-wire loop802fits around and can be slid along the catheter708.

Bringing many of the described components together,FIG. 10is an illustration showing an embodiment of the interaction between a tip section120, a docking section704, and a hot-wire loop section of a fenestration device802configured to aid in the in-situ fenestration of tubular stentgrafts according to one embodiment of the disclosure. A tip section120is positioned on the exterior of a tubular stentgraft1004. The tip section120is magnetically docked with a docking section704which is positioned on the interior of the tubular stentgraft1004directly opposite the tip section120. A catheter708is attached to the docking section704and said catheter708extends out the distal end of the tubular stentgraft1004. The fenestration portion of an electric hot-wire loop802surrounds and is guided by the catheter708. The body of the fenestration portion804may extend distally from the fenestration portion of the electric hot-wire loop802, and runs approximately parallel to the catheter708. The fenestration portion of the electric hot-wire loop802may be fed up along the catheter708until it comes into contact with the portion of the stentgraft nearby the docking section704. Once the fenestration portion802comes into contact with the stentgraft, the hot-wire loop802may be activated, thereby excising the portion of the stentgraft held between the tip section120and the docking section704. A sharp-tipped guidewire1002runs through the tip section120, the tubular stentgraft1004, the docking section704, and the catheter708. The sharp-tipped guidewire1002is used to ensure that the tip section120, and the docking section704are lined up in a desired configuration such that the lumen within each piece allows for the sharp-tipped guidewire1002to run through both sections.

Further illustrating the interaction between certain components,FIG. 11shows an embodiment of how a hot-wire loop section of a fenestration device excises a portion of a tubular stentgraft. A tip section120is situated directly opposite from a magnetically docked docking section704, with only a tubular stentgraft1004separating the two sections. A fenestration portion of an electric hot-wire loop802has advanced along the catheter708it surrounds such that the fenestration portion makes contact with the tubular stentgraft1004, thus excising a portion of the stentgraft. The body of the fenestration section804runs distally away from the fenestration portion802approximately parallel to the catheter708. A sharp-tipped guidewire1002runs coaxially through the tip section120, the tubular stentgraft1004, the docking section704, and the catheter708.

A method of magnet assisted in-situ fenestration of a stentgraft may be described with respect to the flow chart ofFIG. 12. A tip section120is placed into a branch vessel at block1202. A surgical stentgraft1004is deployed into the main vessel at block1204thereby blocking the branch vessel containing the tip section120. Next, the docking station704is placed into the stentgraft1004at block1206. The tip section120is then pulled towards the stentgraft1004such that it causes the tip section120and the docking section704to magnetically dock at block1208. Next, an electric hot-wire loop802is guided at block1210to the location where the tip section120and the docking section704are docked. Then, the electric hot-wire loop is used to excise the stentgraft portion held between the tip section120and the docking section704at block1212.

Further explaining initial steps of the method in certain embodiments,FIG. 13illustrates how and where the tip section120is placed into the desired location according to one embodiment of the disclosure. Initially, a guidewire102may be passed up an entry vessel1308, through the main vessel1302, and into a branching vessel1304. Then, a tip section120along with any detachably connected catheters202may be passed along the guidewire102. A guidewire106may be attached to the side of the tip section120.FIG. 14continues the illustration ofFIG. 13according to one embodiment of the disclosure. InFIG. 14, the tip section120may be detached from both a small catheter404and a larger catheter202. Next, the two catheters202,404may then be removed from the patient's body.FIG. 15continues the illustration ofFIG. 13andFIG. 14, and demonstrates the side-attached guidewire106being used to advance the tip section120along the guidewire102until the tip section120is placed as deeply into the branching vessel1304as the vessel diameter will permit. A catheter may then be placed over the side-attached guidewire106in order to increase column strength to further enable the advancement of the tip section120along the guidewire102. Once the tip section120is in the desired location, the guidewire102may be withdrawn from the branching vessel and removed from the patient's body.

FIG. 16further illustrates how to excise the desired portion of the stentgraft1004once the tip section is in place, according to one embodiment of the disclosure. Once the tip section120is in place in the branching vessel1304, a stentgraft1004may be deployed in a position to bypass the aneurysm1602that has occurred in the main vessel1302. Once the stentgraft1004is in place, a docking section704along with at least one attached catheter708may be passed into the stentgraft.FIG. 17continues the illustration ofFIG. 16. InFIG. 17, one embodiment of the disclosure is shown as the side-mounted guidewire106is pulled causing the tip section120to be pulled towards the stentgraft1004. As the tip section120comes into contact with the stentgraft1004, it may magnetically dock with the docking section704with only a portion of the stentgraft1004held between the tip section120and the docking section704. Once the magnetic docking as occurred, a sharp-tipped guidewire1002may be passed through any catheter708attached to the docking section704, the docking section704, the portion of the stentgraft held between the two magnets, and the tip section120. The sharp-tipped guidewire1002in this context is used to ensure that the tip section120and the docking section704are lined up in the desired configuration. Lastly, an electric hot-wire loop802,804may be passed over the catheter708until it comes into the contact with the stentgraft1004, where it excises the portion held between the tip section120and the docking section704.

According to one embodiment of the disclosure, the main vessel1302is the patient's aorta. The branching vessel1304may be a renal artery, but in other embodiments the branching vessel1304may include the gonadal arteries, lumbar arteries, inferior or superior mesenteric arteries, median sacral artery, or the celiac trunk. In one embodiment, the entry vessel1308refers to one of the common iliac arteries.