Abstract:
A system for the intravascular placement of a medical device including a guidewire having a first end and a second end, the first end having a microwhisk positional between a feeding state and a deployed state, a guidewire sheath surrounding the guidewire; and an anchoring device for cooperatively fixing the microwhisk relative to a patient. Also, the method of the intravascular placement of the medical device by inserting the medical device through the body with the guidewire and the microwhisk contained within the guidewire sheath, driving the microwhisk out of the guidewire sheath to position the microwhisk to its deployed state, and engaging the anchoring device from the outside of the body through a body surface into the microwhisk, and further into a stabilizing body component.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to and the benefit of U.S. Provisional Application No. 61/728,862, filed on Nov. 21, 2012, the disclosure of which is incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    One known medical procedure is the catheterization process. During the catheterization process, a small incision is made in the skin at an entry site. A vascular tube called a sheath is inserted into the artery or vein and allows for easy catheter exchanges during the catheterization procedures. Guided by medical imaging, such as x-rays or other technology, the catheter is then inserted through the skin and maneuvered through the artery. Once the catheter is in place, contrast media may be injected into the blood vessel and an angiogram is taken of the blocked artery to help identify the site of the blockage. With medical imaging, such as x-rays or other technology, guidance, a thin wire called a guide wire may then be moved to the site to guide the placement of a diagnostic catheter, as well as any additional medical devices such as an angioplasty balloon catheter or a vascular stent, as desired. 
         [0003]    There are angioplasty procedures that include the placement of a stent, a small, flexible tube made of plastic or wire mesh to support a damaged blood vessel wall. These stents may be self-expandable or balloon expandable, for example. Once the stent is in place, it may remain in the body permanently, acting as a scaffold for the damaged blood vessel. The guide wire, catheter, and any additional medical devices may then be removed from the patient through the entry site. 
         [0004]    Technical difficulties in carotid artery stenting have arisen, particularly in the elderly population, due to arch vessel tortusity and aortic arch elongation and distortion. Stenting in this situation has resulted in adverse events, such as dislodgement of the delivery system from the target vessel during the procedure or failure to catheterize with large-caliber sheaths despite numerous attempts. In extreme cases, tears in the carotid artery and aortic arch can result. Also these excessive unsuccessful manipulations can cause plaque embolization from the aortic arch or carotid origin, and can result in a stroke during the procedure. One approach previously used has been obtaining through-and-through guidewire access using a surgical cutdown of the superficial temporal artery to facilitate the carotid artery stenting in these situations. The through-and-through access improves the ability to stabilize and manipulate the guidewire during the procedure and thus facilitates intervention, which may include carotid stenting, intracranial intervention, or other interventional procedures. 
       SUMMARY 
       [0005]    A system for the intravascular placement of a medical device includes a guidewire having a first end and a second end, the first end having a microwhisk positional between a feeding state and a deployed state, a guidewire sheath surrounding the guidewire, and an anchoring device for cooperatively fixing the microwhisk relative to a patient. 
         [0006]    The microwhisk may be various shapes. For example, the microwhisk may have a generally elliptical shape in its deployed state. In some embodiments, the microwhisk may have a bulbous shape having a rounded end that is joined to the guidewire by a tapering portion. Furthermore, the generally elliptical-shaped microwhisk may have a pointed end. In some embodiments, the microwhisk is disposed in the tip of a micro catheter and the pointed end of the microwhisk aids in steering the micro catheter through the vessel. The microwhisk may include at least two wire loops. In some embodiments, the microwhisk includes four wire loops, while in other embodiments the microwhisk has six wire loops. In embodiments, the continuity of the guidewire and the multiplicity of the wire loops allows the microwhisk to withstand the tension applied after it is anchored in place. 
         [0007]    The anchoring device may include a handle portion and a pin portion. The pin portion may extend perpendicularly from the handle portion or any other suitable angle. The pin portion may, for example, be a needle. The needle may be between 21 gauge and 25 gauge inclusive. The handle portion of the anchoring device may be circular in shape and be divided into at least two hollow sections by at least one dividing member. In other embodiments, the handle portion may have two, three, four, or more dividing members configured to assist in aligning the pin portion under a fluoroscope or similar device. The handle portion may alternatively be a needle-hub. 
         [0008]    Various aspects will become apparent to those skilled in the art from the following detailed description and the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    Reference is made to the accompanying drawings in which particular embodiments and further benefits of the invention are illustrated as described in more detail in the description below in which: 
           [0010]      FIG. 1  is a side perspective view of a system for the intravascular placement of a medical device, 
           [0011]      FIG. 2  is a partial cross-section view of the system for the intravascular placement of a medical device of in  FIG. 1 , 
           [0012]      FIG. 3  is a side perspective view of another embodiment of the system for the intravascular placement of a medical device, 
           [0013]      FIG. 4  is a partial cross-section view of the system for the intravascular placement of a medical device of  FIG. 3 , 
           [0014]      FIG. 5  is a perspective view of another embodiment of the system for the intravascular placement of a medical device; and 
           [0015]      FIG. 6  is a side view of another embodiment of the system for the placement of a medical device 
       
    
    
     DETAILED DESCRIPTION 
       [0016]      FIG. 1  shows a system for the intravascular placement of a medical device  100 . The system  100  has a catheter apparatus component  110  including a guidewire  112  that is surrounded by a guidewire sheath  114 . The guidewire sheath  114  is formed from a plastic, for example, a polymer or any other suitable, sterilizable material for a medical device. In some embodiments, the guidewire sheath  114  may be referred to as a micro catheter. The guidewire  112  has a microwhisk  116  on one end. The guidewire  112  may be composed of stainless steel which may be monofilament or braided. The guidewire  112  and the microwhisk  116  may instead be composed of a shape-memory alloy, such as nitinol. Alternatively, the shape-memory alloy may be a copper-aluminum-nickel, or a nickel-titanium, and may be created by alloying zinc, copper, gold and iron. Additionally to protect from contamination and promote flexibility, the guidewire  112  may be coated. A coated guidewire may be coated in Teflon, polyurethane, or another lubricious polymer. 
         [0017]    During one exemplary catheterization process, a small incision is made in the skin at an entry site opening to a blood vessel, for example, the femoral artery. The catheter apparatus component  110 , including the guidewire sheath  114  and its enclosed guidewire  112  and microwhisk  114 , may then be guided into the blood vessel. The catheter apparatus component  110  must be flexible enough to travel through a tortuous path. For example, during the feeding process, a user observes the travel of the catheter apparatus component  110  by x-ray, or other technology as the catheter travels through the blood vessel. During the feeding process, the microwhisk  116  remains inside of the guidewire sheath  114 . The catheter apparatus component  110  is fed and guided until it reaches the superficial temporal artery in the side of a patient&#39;s face, or other appropriate artery. The guidewire  112  may then be forced out of an end of the guidewire sheath  114 , causing the microwhisk  116  to exit the guidewire sheath  114  and to deploy. As it is made from a shape memory alloy exhibiting a temperature response at approximately body temperature, the microwhisk  114  will then deploy to its original shape within the superficial temporal artery, or other appropriate artery. In an embodiment, such as illustrated in  FIG. 5 , a guidewire  312  has an end portion  318  extending from the microwhisk  116 . The end portion of the guidewire may extend out of the catheter apparatus. In one embodiment, the end portion  318  is a flexible portion, and may be formed of the same material as the guidewire  312  on the opposite side of the microwhisk. In another embodiment, the end portion  318  includes an angled portion  320  that is angled relative to the axis of the guidewire to facilitate navigation of the guidewire and catheter through the vessel. In an embodiment, the angled portion is angled approximately  45  degrees relative to the axis of the guidewire. 
         [0018]    In another exemplary process, the presently disclosed system may be used to access and navigate a type III aortic arch. A first catheter, such as a Simmons catheter or other catheter having a reverse curve or hook configuration, may be used to gain access to the ascending aorta and carotid artery and to secure the catheter in place. A micro catheter or guidewire sheath may then be advanced through the first catheter and advanced into the carotid artery. In one embodiment, a guidewire having a microwhisk is disposed within the micro catheter. The microwhisk has a tip that may be angled to facilitate selection of the external carotid artery and navigate the micro catheter to the desired location. Upon reaching the desired location, the microwhisk may be extended from the micro catheter allowing the microwhisk to expand and be secured in the vessel with an anchoring device as discussed below. In another embodiment, a conventional guidewire may be used to advance the micro catheter to the desired location. Upon reaching the desired location, the conventional guidewire may be removed, and the guidewire having a microwhisk may be inserted and advanced through the catheter until the microwhisk extends from the micro catheter and expands to be secured in the vessel. Once the microwhisk is secured, a carotid stenting or other procedure may be performed. In this manner the system may provide a stabilized platform for intervention in tortuous arteries of the head, neck or other extremities. 
         [0019]    The system  100  also has an anchoring device  120  component. The device may include a pin portion  122  and a handle portion  124 . Further, the handle portion may take on various forms, such as the embodiment shown in  FIG. 1 , wherein the handle portion  124  is circular and is divided into three hollow sections by dividing member  126 . The dividing member may be positioned to facilitate use of the anchoring device under a fluoroscope such that the handle portion  124  assists in aligning the pin portion  122  at the desired location. In this manner, the handle portion  124  provides means for aligning the pin portion  122  with the desired target location to intersect with the microwhisk deployed in the vessel. In other embodiments, the handle portion  124  may be divided into four hollow sections. 
         [0020]    As shown in  FIG. 2 , the anchoring device  120  may include a pin portion  122  extending perpendicularly from the handle portion  124 . The pin portion  122  may take the form of various instruments including, for example, a needle. The pin portion may be a needle less than or equal to 25 gauge. In addition, the pin portion may be a needle having a size between 21 gauge and 25 gauge. In another case, the pin portion may have a threaded portion, such as a screw tip. The threaded portion may assist in temporarily securing the pin portion, such as to a patients skull or other bone. 
         [0021]    Referring again to  FIG. 2 , the microwhisk  116  may have at least two wire loops  118 . In one embodiment, a first wire loop is oriented at a  90  degree angle to the second wire loop to form a cage configuration. In another example, the microwhisk may include three wire loops with each loop offset by approximately  60  degrees to form a cage configuration. In this manner, the microwhisk may be accessible regardless of rotation of the microwhisk within the artery or other vessel. In another embodiment, a guidewire  332  includes a microwhisk  336  having four wire loops such as illustrated in  FIG. 6 . In embodiments, each wire loop lies in a plane that passes through the axis of the guidewire. In this manner the wire loops form a microwhisk with a plurality of openings defined between successive wire loops. The openings may be parallel with the axis of the guidewire to facilitate capturing an anchoring device inserted substantially perpendicular to the axis of the guidewire. 
         [0022]    The microwhisk  116  may have a generally elliptical shape in its deployed state. The size of the microwhisk may be selected for the artery or vessel. For example, for a superficial temporal artery, the microwhisk may have a diameter from 1.5 millimeters to 5 millimeters, however other sizes may also be used. When the microwhisk  116  is in its deployed state in the superficial temporal artery, the pin portion  122  of the anchoring device  120  is inserted through a skin surface on the patient&#39;s face by pushing, hammering, or screwing or any other insertion mechanism. In an example, the pin portion  122  is inserted substantially perpendicularly to the artery in which the microwhisk is positioned. Using medical imaging, such as x-rays or other technology, the pin portion  122  is guided to the location of the microwhisk  114 , where the pin portion  122  passes through the wire loops  118  of the microwhisk  116 , and an end of the pin portion  122  is inserted into the skull bone of the patient, thereby stabilizing the microwhisk  116  and guidewire  112 . The stabilization of the catheter  110  increases the ease of the angioplasty and stenting processes. 
         [0023]      FIG. 3  shows an alternate embodiment of a system for the intravascular placement of a medical device  200 . The system  200  has a catheter apparatus component  210  including a guidewire  212  that is surrounded by a guidewire sheath  214 . The guidewire sheath  214  is formed from a plastic, for example a polymer or any other suitable, sterilizable material for a medical device. The guidewire  212  has a microwhisk  216  on one end. The guidewire  212  is composed of stainless steel which may be monofilament or braided. The guidewire  212  and the microwhisk  216  may instead be composed of a shape-memory alloy, such as nitinol. Alternatively, the shape-memory alloy may be a copper-aluminum-nickel, or a nickel-titanium, and may be created by alloying zinc, copper, gold and iron. Additionally, to protect from contamination and promote flexibility, the guidewire  212  may be coated. A coated guidewire may be coated in Teflon, polyurethane, or another lubricious polymer. 
         [0024]    During one exemplary catheterization process, a small incision is made in the skin at an entry site opening to a blood vessel, for example, the femoral artery. The catheter apparatus component  210 , including both the guidewire sheath  214  and its enclosed guidewire  212  and microwhisk  214 , may then be guided into the blood vessel. The catheter apparatus component  210  must be flexible enough to travel through a tortuous path. For example, during the feeding process, a user observes the travel of the catheter apparatus component  210  by x-ray, or other technology as the catheter travels through the blood vessel. During the feeding process, the microwhisk  216  remains inside of the guidewire sheath  214 . The catheter apparatus component  210  is fed until it reaches the superficial temporal artery in the side of a patient&#39;s face. The guidewire  212  may then be forced out of an end of the guidewire sheath  214 , causing the microwhisk  216  to exit the guidewire sheath  214  and to deploy. As it is made from a shape memory alloy exhibiting a temperature response at approximately body temperature, the microwhisk  214  will then deploy to its original shape within the superficial temporal artery. 
         [0025]    The system  200  also has an anchoring device  220  component. The device may include a pin portion  222  and a handle portion  224 . Further, the handle portion may take on various forms, such as the embodiment shown in  FIG. 3 , wherein the handle portion  224  is a needle hub  228 . 
         [0026]    As shown in  FIG. 4 , the anchoring device  220  may include a pin portion  222  extending perpendicularly from the handle portion  224 . The pin portion  222  may take the form of various instruments including, for example, a needle. In one instance, the pin portion may be a needle less than or equal to 25 gauge. In another case, the pin may be a threaded fastener. 
         [0027]    Referring again to  FIG. 4 , the microwhisk  216  may have at least two wire loops  218 . The microwhisk  216  in its deployed state may have a generally elliptical shape with a pointed end. When the microwhisk  216  is in its deployed state in the superficial temporal artery, the pin portion  222  of the anchoring device  220  is inserted through a skin surface on the patient&#39;s face by pushing, hammering, or screwing or any other insertion mechanism. Using medical imaging, such as x-rays or other technology, the pin portion  222  is guided to the location of the microwhisk  214 , where the pin portion  222  passes through the wire loops  118  of the microwhisk  116 , and an end of the pin portion  222  is inserted into the skull bone of the patient, thereby stabilizing the microwhisk  216  and guidewire  212 . The stabilization of the catheter  210  increases the ease of the angioplasty and stenting processes. 
         [0028]    The systems and method described here may provide greater control over the manipulation and positioning of a guidewire for the placement of medical devices, such as stents. The improved control may improve the ability place medical devices, particularly in patients with arch vessel tortuosity and/or aortic arch elongation, both of which become progressively worse with age. Similarly, the presently disclosed system and method may improve access through tortuous iliac vessels. The present disclosure may assist in addressing the mechanical problems of prior methods wherein the vector forces produced while pushing the endovascular materials are out of line or even opposite to the vector forces necessary for appropriate delivery to the target vessel. Embodiments of this system may also be useful for lower extremity vascular interventions where there are acutely angled aortic bifurcations. 
         [0029]    While certain embodiments have been described, it must be understood that various changes may be made and equivalents may be substituted without departing from the sprit or scope. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from its spirit or scope.