Abstract:
A guiding catheter assembly and a method for using the assembly for treating a stenotic lesion. The guiding catheter assembly includes a guiding catheter having an occluder balloon mounted distally thereon. A flexible leader is slidably disposed through a primary lumen of the guiding catheter and has a tapered distal portion extending distally of the guiding catheter. The guiding catheter may have a preformed curve at the distal end. An embodiment of the guiding catheter may also comprise at least one steering wire disposed within a steering lumen in the guiding catheter, the steering wire being operable to deflect the distal end of the guiding catheter.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates generally to intraluminal devices, and more particularly, to a guiding catheter assembly for advancing a medical device through a patient&#39;s vasculature.  
       BACKGROUND OF THE INVENTION  
       [0002]     Stenotic lesions form on the lumen walls of a blood vessel to create narrowings that restrict blood flow there through, and may comprise a hard, calcified substance and/or a softer thrombus material. Interventional catheterization procedures such as balloon angioplasty, stent deployment, atherectomy, and thrombectomy are well known and have proven effective in the treatment of such stenotic lesions. Such modalities require the insertion of a therapy catheter through a patient&#39;s vasculature.  
         [0003]     Recently, devices have been developed that address concerns relating to atheroembolization; i.e. the obstruction of blood vessels by stenotic debris that may be released during interventional catheterization therapies such as those mentioned above. Distal protection devices (DPDs) such as filters and occluders represent one class of intravascular devices that can be used to prevent atheroembolization. A filter mounted on a guidewire or a catheter may be positioned distally of a stenotic lesion to capture and remove embolic debris without causing hemostasis. Alternatively, an occluder guidewire or catheter may be positioned distally of a stenotic lesion to temporarily stop the flow of blood and any stenotic debris that may have become entrained in the blood. The contaminated blood is aspirated from the treated area before the occluder device is collapsed to permit resumption of blood flow.  
         [0004]     Occlusion devices may also be placed proximally of a stenotic lesion to provide proximal protection. Such proximal occluders may be used alone to prevent atheroembolization, or may be used in conjunction with a distal occluder to form an isolated treatment chamber about the lesion to be treated. Preliminary deployment of a proximal occlusion device may be advantageous in preventing atheroembolization because advancing a treatment catheter into a tight stenosis can dislodge particulate debris, even before the stenosis is opened.  
         [0005]     A guiding catheter is typically used to direct a treatment catheter to a stenotic lesion, especially if the lesion is remote from the vascular assess site. One type of guiding catheter that may be utilized is described in U.S. patent appn. No. 2002/0026145 A1 entitled “Method and Apparatus for Emboli Containment” to Bagaoisan et al. (“Bagaoisan”). Typical of most guiding catheters, the Bagaoisan catheter is pre-curved at the distal end to set and hold a supporting position in the vasculature while the therapeutic catheter crosses and treats the lesion. Additionally, the Bagaoisan catheter includes an expandable sealing balloon disposed around the guiding catheter&#39;s distal end that, when appropriately positioned, may be inflated to provide embolic protection by proximal occlusion. However, the Bagaoisan catheter may present certain drawbacks. For example, insertion of the sealing balloon for proximal occlusion requires deeply intubating the catheter tip into the selected vessel. Ordinarily, deep intubation with a guiding catheter is to be avoided to prevent scraping injury to the intimal lining of the vessel wall. Furthermore, a catheter that is designed for deep intubation and occlusion has a preformed curve with a tip portion that is longer than a similar curve not intended for deep intubation. With such an extended tip portion, it may be difficult to advance the guiding catheter through the patient&#39;s vasculature.  
         [0006]     It would therefore be desirable to provide a guiding catheter capable of deep intubation within a patient&#39;s vasculature with minimal trauma to the patient&#39;s vessels. It would further be desirable to provide a device for use within a guiding catheter to ease advancement of the guiding catheter through the patient&#39;s vasculature. It would also be desirable to provide a guiding catheter capable of being steered during insertion by the user. Other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims taken in conjunction with the accompanying drawings.  
       BRIEF SUMMARY OF THE INVENTION  
       [0007]     In one exemplary embodiment, a guiding catheter assembly is provided that includes a guiding catheter, a balloon, and a flexible leader. The guiding catheter has a distal end and a proximal end and has a primary lumen and an inflation lumen that extend there through. The inflation lumen has a proximal port, and the balloon is mounted adjacent the distal end of the guiding catheter and is in fluid communication with the proximal port. The flexible leader is configured to be slidably disposed within the primary lumen of the guiding catheter and has a tapered distal portion.  
         [0008]     In another exemplary embodiment of the invention, a guiding catheter assembly is provided that includes a guiding catheter, a steering wire, a balloon, and a flexible leader. The guiding catheter has distal and proximal ends, and has a primary lumen, a steering lumen, and an inflation lumen each extending there through. The steering wire is disposed within the steering lumen and has a distal end attached to the distal end of the guiding catheter. The inflation lumen has a proximal port, and the balloon is mounted adjacent the distal end of the guiding catheter and is in fluid communication with the proximal port. The flexible leader is configured to be slidably disposed within the primary lumen and has a tapered distal portion.  
         [0009]     In yet another exemplary embodiment, a guiding catheter assembly is provided including a guiding catheter, a steering wire, and a balloon. The guiding catheter has distal and proximal ends, and a primary lumen, a steering lumen, and an inflation lumen each extending there through. The steering wire is disposed within the steering lumen and has a distal end coupled to the distal end of the guiding catheter. The inflation lumen has a proximal port, and the balloon is mounted adjacent the distal end of the guiding catheter and is in fluid communication with the proximal port.  
         [0010]     In still another exemplary embodiment, a method is provided for treating a stenotic lesion in a vessel of a patient. The method includes providing a guiding catheter assembly comprising a guiding catheter having an occlusion balloon mounted thereon and a flexible leader extending there through, advancing the guiding catheter assembly through the vessel to a location adjacent the stenosis, inflating the balloon to occlude the vessel, and withdrawing the flexible leader from the guiding catheter.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     The following drawings are illustrative of a particular embodiment of the invention and therefore do not limit the scope of the invention. They are presented to assist in providing a proper understanding of the invention. The drawings are not to scale and are intended for use in conjunction with the explanations in the following detailed description. The present invention will hereinafter be described in conjunction with the appended drawings, wherein like reference numerals denote like elements, and:  
         [0012]      FIG. 1  is a longitudinal cross-sectional view of an exemplary guiding catheter assembly in accordance with the invention;  
         [0013]      FIG. 2  is a cross-sectional view taken along line  2 - 2  of the exemplary guiding catheter assembly illustrated in  FIG. 1 ;  
         [0014]      FIG. 3  is a longitudinal cross-sectional view of the guiding catheter shown in  FIG. 1 ;  
         [0015]      FIG. 4  is a longitudinal cross-sectional view of the flexible leader shown in  FIG. 1 ; and  
         [0016]      FIGS. 5-11  illustrate the use of the guiding catheter assembly shown in  FIGS. 1 and 2  during a typical angioplasty procedure. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0017]     The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary, or the following detailed description.  
         [0018]     Referring to  FIGS. 1 and 2 , guiding catheter assembly  100  is provided according to an exemplary embodiment of the present invention. Guiding catheter assembly  100  comprises guiding catheter  200 , flexible leader  300 , and guidewire  400 , each of which will be discussed in more detail below. Occlusion balloon  202  is mounted adjacent the distal end of catheter  200 , and hub  204  is coupled to the proximal end of catheter  200 . Occlusion balloon  202  and hub  204  are in fluid communication via inflation lumen  210 . Steering wires  206  and  208  are disposed within steering lumens  212  and  214 , respectively, that extend between the distal and proximal ends of guiding catheter  200 . Guiding catheter  200  further comprises primary lumen  216  that also extends between the distal and proximal ends of guiding catheter  200 . Flexible leader  300 , configured for slidable movement within primary lumen  216 , includes tapered distal portion  302  that is configured to protrude out of guiding catheter  200  through distal port  218 . Flexible leader  300  is provided with wire lumen  304  for slidably receiving guidewire  400  there through.  
         [0019]     Guiding catheter  200  is configured to have sufficient structural integrity to advance through a patient&#39;s vasculature to remote arterial locations without buckling. In this regard, guiding catheter  200  may be constructed of one or more flexible biocompatible materials, including, but not limited to, polyethylene, polypropylene, polyurethane, polyesters, or PEBAX® polyethylene block amide copolymer, available from ELF Atochem, Philadelphia, Pa., U.S.A.  
         [0020]     If desired, a layer of braided filaments that resists kinking and enhances longitudinal transmission of rotation may be embedded within guiding catheter  200 . Furthermore, the stiffness of guiding catheter  200  may be varied along the length thereof. For example, the distal end of guiding catheter  200  may possess physical properties that are different from those associated with the catheter&#39;s proximal end; e.g. guiding catheter  200  may become increasingly flexible in a distal direction.  
         [0021]      FIG. 3  is a longitudinal cross-sectional view of guiding catheter  200 . Guiding catheter  200  may be substantially straight, or guiding catheter  200  may include curve  220 , shown in phantom, proximate the distal region of guiding catheter  200 . Any one of a number of pre-formed curve shapes may be incorporated into guiding catheter  200 , such as Judkins-type or Amplatz-type curves, as non-limiting examples. Curve  220  may be pre-formed utilizing various known methods including, but not limited to, the method disclosed in U.S. Pat. No. 5,902,287 entitled “Guiding Catheter and Method of Making Same.” A desired curve  220  may be manually created from a straight or pre-formed distal region of guiding catheter  200  by manipulation of one or more steering wires, as will be described more fully below.  
         [0022]     The distal end of guiding catheter  200  is configured to provide safe advancement of the catheter through a patient&#39;s vasculature. In one exemplary embodiment, the distal end of guiding catheter  200  is smooth and blunt. In another embodiment, the distal end is rounded. In yet another exemplary embodiment, soft distal segment  222  (shown in phantom) is formed of a soft material and coupled to the distal end of guiding catheter  200 .  
         [0023]     Occlusion balloon  202  is mounted to guiding catheter  200  utilizing any suitable technique known in the art (e.g. adhesive or heat bonding). Occlusion balloon  202  is configured to inflate and expand to a diameter sufficient to occlude a vessel within which it is positioned. The balloon may be formed of an elastic material, such as styrene-ethylene-butylene-styrene (SEBS), silicone, or latex. Alternatively, occlusion balloon  202  may be made of an inelastic, flexible biocompatible polymer.  
         [0024]     Hub  204  is coupled to the proximal end of guiding catheter  200  and may be made of a hard polymer (e.g. medical grade polycarbonate, polyvinyl chloride, acrylic, acrylonitrile butadiene styrene (ABS), or nylon) or a metal that possesses the requisite structural integrity to provide a functional access port to guiding catheter  200 ; i.e. for balloon inflation or fluid aspiration. Hub  204  further comprises steering mechanisms  224  and  226  including actuators  228  and  230 , respectively (e.g. reels). Steering mechanisms  224  and  226  are preferably at least partially disposed within housings  232  and  234 , respectively.  
         [0025]     Hub  204  is provided with balloon inflation lumen  236 , device lumen  238 , and at least first and second steering wire lumens  240  and  242 . Each of lumens  236 ,  238 ,  240 , and  242  adjoins a corresponding guiding catheter lumen  210 ,  216 ,  212 , and  214 , respectively, each of which will be discussed in more detail below.  
         [0026]     Inflation lumen  210  carries fluid to and from occlusion balloon  202  to inflate and deflate occlusion balloon  202 , respectively. In this regard, inflation lumen  210  extends substantially the length of guiding catheter  200  and includes distal balloon inflation port  244  and proximal fluid supply port  246 . Preferably, inflation lumen  210  is formed adjacent the outer periphery of guiding catheter  200 . Although a single inflation lumen  210  is depicted in  FIG. 3 , it will be appreciated that additional inflation lumens may be employed.  
         [0027]     Steering lumens  212  and  214  each extend substantially the length of guiding catheter  200  and include wire entry ports  248  and  250 , respectively, at the proximal end of guiding catheter  200 . Each steering lumen  212  and  214  terminates within guiding catheter  200  adjacent its distal end and has a diameter sufficient to permit steering wires  206  and  208  respectively to slidably move therein. In the embodiment depicted in  FIGS. 1-3 , steering lumens  212  and  214  are substantially diametrically opposed; however; those with skill in the art will appreciate that this is not a requirement. Additionally, although two steering lumens are shown, it will be appreciated that the number of steering lumens may be varied to suit particular needs and/or applications.  
         [0028]     Steering wires  206  and  208  are disposed within steering lumens  212  and  214 , respectively. The steering wires may be comprised of a variety of materials having sufficient strength to bend guiding catheter  200  when pulled. In this regard, steering wires  206  and  208  are attached adjacent the distal end of guiding catheter  200  in one of a number of ways. In the exemplary embodiment shown in  FIG. 3 , the distal end of each steering wire  206  and  208  is anchored adjacent the distal end of the catheter as is shown at  252  and  254  respectively. The proximal ends of each steering wires  206  and  208  are coupled to actuators  228  and  230 , respectively. Rotating the actuators causes steering wires  206  and/or  208  to pull at the distal end of guiding catheter  200  to deflect the distal end of guiding catheter  200  (e.g. create curve  220 ). That is, as configured in  FIG. 3 , pulling on wire  208  will cause the distal end of catheter to bend downward (shown in phantom). Pulling on wire  206  will cause an upward deflection.  
         [0029]     Those with skill in the art may appreciate that actuators  228  and  230  may take other forms, such as manually operable slides to push/pull on steering wires  206  and  208 . Skilled artisans will also recognize that the terms “steer” and “steering,” as used herein generally refer to various wires, lumens and actions causing deflection of the distal end of guiding catheter  200 . However, it is to be understood that steering of guiding catheter  200  may include manual rotation of the catheter proximal end to cause rotation of the catheter distal end, with or without actions to cause simultaneous deflection of the distal end.  
         [0030]     As noted above, guiding catheter  200  is provided with primary lumen  216  including inlet port  256  and distal port  218 . Primary lumen  216  may include slippery interior surface  258  for reducing frictional forces between the interior surface  258  and devices that may be moved through primary lumen  216 . In one exemplary embodiment, interior surface  258  is provided with a slippery coating, such as a silicone compound or a hydrophilic polymer. In another exemplary embodiment, interior surface  258  includes liner  260  formed from a slippery material that is coupled to interior surface  258 . Those with skill in the art may appreciate that any one of numerous low-friction, biocompatible materials such as, for example, fluoropolymers (e.g. PTFE, FEP), polyolefins (e.g. polypropylene, high-density polyethylene), or polyamides, may be used to make interior surface  258 .  
         [0031]     With reference to  FIG. 4 , flexible leader  300  may be inserted into primary lumen  216  and has tapered distal portion  302  that is configured to protrude from distal port  218  as shown in  FIG. 1 . Flexible leader  300  may be constructed of any suitable biocompatible material or combinations of materials, including, but not limited to, a fluoropolymer, a polyolefin, a polyurethane, or PEBAX, and may have either a stiff or flexible construction. Distal portion  302  is provided with tip  306 , which is formed of relatively soft material to minimize trauma to the patient&#39;s vessels. Tip  306  may be closed and rounded, or tip  306  may have a distal opening to wire lumen  304 , which will be described below. The outer diameter of flexible leader  300  may have a close sliding fit with guiding catheter  200  to substantially fill primary lumen  216 . Alternatively, a distal region of flexible leader  300  may have a close sliding fit within distal port  218 , while the remaining portion of flexible leader  300  is smaller in diameter to provide greater clearance through primary lumen  216 . Distal portion  302  provides a tapered transition between tip  306  and guiding catheter  200 , and serves as a leading surface when guiding catheter assembly  100  is advanced through a patient&#39;s vasculature.  
         [0032]     Flexible leader  300  is further provided with wire lumen  304  that has a diameter sufficient to allow guidewire  400  to slidably move there through. As will be appreciated by those with skill in the art, the diameter of wire lumen  304  may or may not be uniform along its entire length. For example, in one alternative embodiment (not shown) of the flexible leader, the wire lumen proximal to the distal tip is larger in diameter than the opening in the distal tip to allow reduced wall thickness, which may result in an increase in flexibility along the length of flexible leader  300 .  
         [0033]     Guidewire  400  is used to guide medical devices such as guiding catheter  200  and/or therapeutic catheters to a desired position within the patient&#39;s vasculature. Guidewire  400  is conventional, having sufficient flexibility, especially at a distal end, to pass safely through a patient&#39;s vasculature, while having sufficient stiffness to partially straighten a pre-formed curve  220  of guiding catheter  300 .  
         [0034]      FIGS. 5-11  illustrate a method for the operation and use of guiding catheter assembly  100 . Guiding catheter assembly  100  is advanced into vessel lumen  500  until occlusion balloon  202  is positioned between the ostium (not shown) and stenosis  502  to be treated, as illustrated in  FIG. 5 . In one exemplary embodiment of the method, guidewire  400  is first advanced to the desired position and guiding catheter  200  and flexible leader  300  are advanced over guidewire  400 . In another exemplary embodiment, guiding catheter  200 , flexible leader  300 , and guidewire  400  are advanced to the desired position as a single unit. It will be recalled from above that a practitioner may use steering wires  206  and  208  ( FIGS. 1 and 2 ) to deflect the distal end of guiding catheter  200  to aid the practitioner in the advancement of guiding catheter assembly  100  through a patient&#39;s vasculature. After being properly positioned within vessel lumen  500 , occlusion balloon  202  is inflated until it engages the sidewall of the vessel as shown in  FIG. 6 . Flexible leader  300  and/or guidewire  400  may be retracted from primary lumen  216  before or after inflation of occlusion balloon  202 .  
         [0035]      FIGS. 7-8  illustrate an exemplary procedure wherein balloon dilatation catheter  510 , including dilatation balloon  512 , is advanced through primary lumen  216  until the balloon reaches a desired position within stenosis  502 . Dilatation balloon  512  is then inflated to dilate the stenosis. Balloon dilatation catheter  510  may then be removed, and any debris present may be aspirated, either directly into guiding catheter distal port  218  or, alternatively, into aspiration catheter  514 , which may be advanced to the treated area within vessel lumen  500 , as shown in  FIG. 9 . If used, aspiration catheter  514  may be subsequently withdrawn from primary lumen  216 , as shown in  FIG. 10 . Then, occlusion balloon  202  is deflated as shown in  FIG. 11 , allowing blood flow to resume. Lastly, guiding catheter  200  is withdrawn from vessel lumen  500 .  
         [0036]     Thus, there has been provided a guiding catheter assembly configured for deep intubation within a patient&#39;s vasculature with minimal trauma to the patient&#39;s vessels. Furthermore, the guiding catheter assembly provides a smooth transition between the guiding catheter&#39;s distal end and the patient&#39;s vasculature to ease advancement of the guiding catheter through the patient&#39;s vasculature. The device is, if desired, also capable of being steered by the operator during insertion.  
         [0037]     While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the exemplary embodiment or exemplary embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope of the invention as set forth in the appended claims and the legal equivalents thereof.