Abstract:
Medical devices, systems and methods for providing visualization as well as support and/or stability for blood vessels during procedures for inserting electrical leads are disclosed. One aspect of the device may include a longitudinal member having a distal end and a proximal end, an expandable element near the distal end of the longitudinal member for providing support to the blood vessel, and a contrast release port near the distal end of the longitudinal member for releasing a contrast medium into the blood vessel to visualize the blood vessel.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Patent Application No. 61/094,374, titled “Method and Device for Inserting Electrical Leads” and filed on Sep. 4, 2008. 
    
    
     FIELD OF THE INVENTION 
     This invention relates generally to catheters, and in particular to a catheter device for providing visualization and support to the subclavian vein for the delivery of electrical leads to the heart. 
     DESCRIPTION OF THE RELATED ART 
     The invention relates to the field of cardiology and in particular to methods and devices for inserting pacemaker or implantable cardioverter defibrillator (ICD) leads. 
     A pacemaker is typically composed of three parts: a pulse generator, one or more leads, and an electrode on each lead. The pulse generator is a small metal case that contains electronic circuitry that regulates the impulses sent to the heart. The leads are insulated wires that are connected at one end to the pulse generator and on the other end to the inside of the heart. The electrodes on the leads are in contact with the heart wall. 
     The leads are percutaneously inserted into a blood vessel, typically the subclavian vein, with the aid of a sheath or introducer. The leads are advanced through the sheath into the blood vessel and to the heart. 
     A problem often encountered during this procedure is readily accessing the blood vessel so that the leads can be delivered to their intended site. At times, access can be so difficult and time consuming that it may cause the physician to abandon the procedure and reattempt at another time. In addition, properly locating the puncture site for lead insertion is important so as to prevent any potential damage to the underlying tissues or organs. These problems are typically caused by the fact that the target vessel cannot be visualized from outside the body, lacks stability, and is prone to collapsing. 
     Therefore, it is desirable to provide a device which can prepare the target blood vessel for effective and safe delivery of the leads. 
     SUMMARY OF THE INVENTION 
     A catheter device for providing visualization as well as support and/or stability for blood vessels during procedures for inserting electrical leads. In one particular aspect, the catheter device is used when inserting pacemaker or ICD leads through the subclavian blood vessel. 
     In one aspect, the catheter device comprises a longitudinal member having a distal end and a proximal end, an expandable element near the distal end of the longitudinal member for providing support to the blood vessel, and a contrast release port near the distal end of the longitudinal member for releasing a contrast medium into the blood vessel to visualize the blood vessel. At its proximal end, the catheter device comprises a contrast injection port. 
     In various aspects, the expandable element may comprise an inflatable balloon, or a plurality of compressible elements that expand to a balloon like shape, or a compressible coil housed in a protective sheath, which sheath retracts to allow the coil to expand. In one aspect, the catheter device comprises two inflatable balloons. At its proximal end, the catheter device comprises one or more inflation ports for inflating the one or more balloons. 
     As part of a surgical procedure to insert an electrical lead into the subclavian vein of a patient and from there into the heart, a physician first advances the catheter device into the subclavian vein and then causes the expandable member to expand and thereby to support the blood vessel. The physician then releases a contrast medium through the contrast release port into the blood vessel to visualize the blood vessel. Finally, the physician inserts a hollow point needle into the visualized and supported subclavian vein, and then proceeds to insert the electrical lead through the needle and into the subclavian vein. From there the physician navigates the lead into the patient&#39;s heart. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention has other advantages and features which will be more readily apparent from the following detailed description of the invention and the appended claims, when taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  illustrates one embodiment of the catheter device of the present invention. 
         FIG. 2  illustrates two example pairs of guidewires and guiding catheters used to deliver the catheter device of the present invention into the subclavian vein. 
         FIG. 3  shows a guidewire in place in the right subclavian vein, after removal of the corresponding guiding catheter. 
         FIG. 4  shows the catheter device of the present invention tracked over the guidewire and placed in the subclavian vein. 
         FIG. 5  shows the balloons in their inflated state. 
         FIG. 6  shows the injection of a contrast medium into the portion of the subclavian vein that extends between and is supported by the two balloons. 
         FIG. 7  illustrates a syringe and needle used to draw blood to obtain visual confirmation of the presence of the needle in the blood vessel. 
         FIG. 8  illustrates the insertion of an electrical lead through the needle and into the subclavian vein. 
         FIG. 9  shows the deflated proximal balloon and the inserted lead traveling past the deflated balloon and further down the blood vessel towards the heart. 
         FIGS. 10-10A  and  11 A- 11 B show alternative embodiments of the catheter device comprising compressible elements. 
         FIGS. 12A-12B  show an alternative embodiment of the catheter device comprising a compressible coil. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Although the detailed description contains many specifics, these should not be construed as limiting the scope of the invention but merely as illustrating different examples and aspects of the invention. It should be appreciated that the scope of the invention includes other embodiments not discussed in detail above. Various other modifications, changes and variations which will be apparent to those skilled in the art may be made in the arrangement, operation and details of the method and apparatus of the present invention disclosed herein without departing from the spirit and scope of the invention as described here. 
     The catheter device of the present invention is provided for the visualization and support of blood vessels during surgical procedures for inserting electrical leads into blood vessels. One particular use of such a catheter device is for safer and easier insertion of pacemaker or ICD leads through the subclavian blood vessel. 
     In one embodiment, the catheter device comprises two balloons at its distal end which are separated along the length of the catheter device by a small distance. Once the catheter device is inserted into a blood vessel, the balloons are inflated to provide support and/or stability to the portion of the blood vessel that extends between the balloons. The catheter device comprises a port in the space between the balloons for releasing a contrast medium for visualizing the vessel. The contrast medium is injected proximally into the catheter device and travels through the catheter in a distal direction until it flows out of the port between the balloons and into the supported portion of the blood vessel, thereby allowing visualization of the blood vessel. The balloons can be of any number of materials, including but not limited to latex, nylons, PEBAX, polyurethane, polyethylene terephthalate (PET), and silicone. 
       FIG. 1  illustrates one embodiment of the catheter device. Catheter device  100  comprises a longitudinal member  101  with a distal end  101   d  and a proximal end  101   p . The distal end  101   d  comprises two inflatable balloons  102   a  and  102   b  separated by a space. The catheter device  100  comprises a release port  103  in the space between the balloons  102   a  and  102   b  for delivering a contrast medium into the portion of the blood vessel supported by the balloons. 
     At its proximal end  101   p , the catheter device  100  comprises two inflation ports  104   a  and  104   b , a guidewire port  104   c , and a contrast injection port  104   d . The inflation ports  104   a  and  104   b  serve to inflate the balloons  102   a  and  102   b , respectively. The guidewire port  104   c  accepts a guidewire  105 . The contrast injection port  104   d  is configured to accept injection of a contrast medium, to be delivered through the longitudinal member  101  and out of the contrast release port  103  into the supported portion of the blood vessel. In one embodiment, the catheter device  100  comprises an atraumatic tip  106 . Optionally, catheter device  100  comprises one or more radiopaque markers  107  placed along the distal portion of the catheter device  100  and/or around the balloons  102   a  and  102   b.    
     As shown in  FIG. 2 , the guidewire  105 , and typically also a guiding catheter  108 , are inserted into a blood vessel to aid in the delivery of the catheter device  100 . Typically, the guidewire  105  and guiding catheter  108  are introduced through the femorals or brachials, and the guiding catheter  108  is used to direct the guidewire  105  into a subclavian vein  109 . It is noted that  FIG. 2  actually shows two separate example pairs of a guidewire  105  and a guiding catheter  108 . One pair is shown for the delivery of the guidewire  105  into the right subclavian vein  109 , and the other pair is shown for delivery into the left subclavian vein. Once the guidewire  105  is in place in the subclavian vein  109 , the guiding catheter  108  can be removed.  FIG. 3  shows the guidewire  105  in place in the right subclavian vein  109 , after removal of the guiding catheter  108 . The guidewire  105  may be a standard 0.035″ guidewire, or it may be of another type or dimension. 
     Once the guidewire  105  is in place in the subclavian vein  109  and the guiding catheter  108  is removed, the catheter device  100  is tracked over the guidewire  105  and advanced to the subclavian vein  109  at a location just above the first rib  110 , as shown in  FIG. 4 . This serves the purpose of one or more ribs (primarily the first rib) acting as a barrier to prevent damage to the underlying tissue when the hollow point needle is subsequently inserted as described below. 
     Once the catheter device  100  is in place in the subclavian vein  109 , the balloons  102   a  and  102   b  are inflated, using the inflation ports  104   a  and  104   b  at the proximal end  101   p  of the catheter device  100 .  FIG. 5  shows the balloons  102   a  and  102   b  in their inflated state. Once the balloons are inflated, they provide support and/or stability to the portion of the subclavian vein  109  that extends between the balloons, thereby reducing the vessel&#39;s tendency to collapse. The balloons  102   a  and  102   b  may be inflated using CO 2 , saline, or any other suitable fluid. 
     Once the balloons  102   a  and  102   b  are inflated and provide support for the subclavian vein  109 , a contrast medium is injected into the contrast injection port  104   d  at the proximal end  101   p  of the catheter device  100 . The injected contrast medium travels in a distal direction through the longitudinal member  101  and out of the contrast release port  103  into the supported portion of the subclavian vein  109 , as shown in  FIG. 6 . While injection of the contrast medium primarily provides for visualization, it also serves the additional purpose of dilating the subclavian vein  109  and thereby providing additional support and/or stability to the vein. Optionally, the contrast medium itself may be used to inflate the balloons  102   a  and  102   b . Optionally, one or more of the balloons  102   a  and  102   b  comprises one or more radiopaque markers for additional aid in visualization. 
     With the contrast medium present in the supported portion of the subclavian vein  109 , the subclavian can be easily visualized under fluoroscopy. A syringe with a hollow point needle can then be used to draw some blood from the subclavian vein  109  and, upon visual confirmation that the contrast medium is present in the drawn blood, to confirm that the needle is within the subclavian vein  109 . This is shown in  FIG. 7 , wherein a syringe  120  with a needle  121  is used to draw a small amount of blood  122  from the subclavian vein  109  and to confirm the presence of contrast medium in the drawn blood  122 . 
     Upon such visual confirmation of contrast presence using syringe  120  and needle  121 , the syringe  120  is removed and the needle  121  is left in place in preparation for the delivery of one or more electrical leads.  FIG. 8  shows insertion of an electrical lead  130  through the needle  121  and into the subclavian vein  109 . 
     Once the electrical lead  130  is inserted into the subclavian vein  109 , the proximal balloon  102   b  is deflated to allow the lead  130  to be placed further down the blood vessel for delivery to its intended site in the heart. This is illustrated in  FIG. 9 , showing the deflated proximal balloon  102   b  and the lead  130  traveling past the deflated balloon  102   b  and further down the blood vessel towards the heart. 
     In an alternative embodiment, the catheter device  100  comprises one balloon  102   b  and one corresponding inflation port, but not another balloon nor another corresponding inflation port. Once the catheter device  100  is placed into the subclavian vein  109  as described above, the balloon  102   b  is inflated. Inflation of the balloon  102   b  causes the blood to back up distal to the inflated balloon  102   b , thereby dilating and providing support and/or stability to the subclavian vein  109 . Optionally, contrast medium is injected and released via the contrast release port  103  to provide visualization. The physician then proceeds with inserting the electrical leads as described above. It should be noted that the contrast release port  103  can be placed on either side of the balloon. 
     In another alternative embodiment, the catheter device  100  does not comprise inflatable balloons, but instead comprises a number of compressible elements which can be expanded to take a shape similar to a balloon.  FIG. 10  shows such an embodiment, wherein catheter device  100  comprises compressible elements  140  which extend axially along the distal end of the catheter device  100 . Upon activation, and as shown in  FIG. 10A , the elements  140  expand to take a shape similar to a balloon, thereby providing support and/or stability to the portion of the subclavian vein  109  within which the elements  140  reside. The space between elements  140  allows the physician access to the heart without having to remove, compress, or otherwise handle the elements  140 . The elements  140  may be activated to expand via a variety of mechanisms, including but not limited to advancing the proximal end  141   p  of the compressible elements  140  towards the distal end  141   d , or vice versa. This may be accomplished by pulling on the distal end  141   d  to cause it to move towards the proximal end  141   p , or by twisting or rotating the proximal end  141   p  relative to the distal end  141   d  in order to cause the elements  140  to expand outwards, or by similar techniques. Optionally, the elements  140  are radiopaque to allow visualization of the blood vessel  109 . Optionally, the distal portion of the catheter  100  comprises one or more radiopaque markers  142 . 
     In yet another embodiment, as shown in  FIG. 11A , the catheter device  100  comprises a number of compressible elements  150  housed within a protective sheath  151 . The elements  150  may be affixed to a shaft  152  at their proximal end and are open at their distal end, allowing them to expand as the sheath  151  is retracted in a proximal direction.  FIG. 11B  shows the sheath  151  retracted and the compressible elements  150  expanded to their natural shape, thereby providing support and/or stability for the subclavian vein  109 . As with the previous embodiment, the space between the elements  150  allows the physician access to the heart without having to remove, compress, or otherwise handle the elements  150 . In one embodiment, shaft  152  may be a guidewire shaft comprising a guidewire lumen for a guidewire to travel through. Optionally, the elements  150  are radiopaque to allow visualization of the blood vessel  109 . Optionally, the distal portion of the catheter  100  comprises one of more radiopaque markers. 
     In yet another embodiment, as shown in  FIG. 12A , the catheter device  100  comprises a coil  160  to provide visualization and support. The coil  160  is held in its compressed state via a number of mechanisms, including but not limited to using a protective sheath  161 , tension wires (not shown), or other mechanisms. The coil  160  may be affixed to a shaft  162  at its proximal end and is open at its distal end, allowing it to expand as the sheath  161  is retracted in a proximal direction, as shown in  FIG. 12B . Once the physician has inserted one or more electrical leads into the blood vessel, the coil  160  may be retracted to allow the physician unencumbered access to the heart. In one embodiment, shaft  162  may be a guidewire shaft comprising a guidewire lumen for a guidewire to travel through. Optionally, the coil  160  is radiopaque to allow visualization of the blood vessel  109 . Optionally, the distal portion of the catheter  100  comprises one or more radiopaque markers. 
     In yet another embodiment, the catheter device  100  comprises an inflatable balloon on its distal end. After the balloon is advanced to its intended site, it is inflated with a contrast solution to provide both visualization and support. A hollow needle is then inserted through the skin and into the balloon, essentially puncturing the balloon and confirming placement of the needle inside the vessel. The balloon is then deflated and removed and the electrical leads are inserted through the needle and advanced towards the heart as described previously. 
     The compressible members and coils in the above embodiments may comprise a shape memory material such as Nitinol or other materials which can serve its intended purpose. While the above embodiments generally refer to the subclavian vein as the blood vessel being visualized and supported and/or stabilized, it is understood that the catheter device of the present embodiments can be used to visualize and provide support and/or stability to other blood vessels as well. Depending on the access site chosen (femoral, brachial, radial, etc.), the location or orientation of the balloons, compressible elements, coil, contrast release port, etc. may need to be modified to serve their intended purposes. 
     While the above description generally makes reference to electrical leads, the device can be applicable to other non-electrical leads, catheters, or wires which may benefit from a stabilized vessel for insertion. 
     While the above is a complete description of the preferred embodiments of the invention, various alternatives, modifications, and equivalents may be used. Therefore, the above description should not be taken as limiting the scope of the invention which is defined by the appended claims.