Abstract:
A lead delivery system for implanting a lead in a patient&#39;s internal jugular vein (IJV) through a subclavian vein. The system comprises an outer catheter having a distal portion, an intermediate portion, and a proximal portion. The outer catheter defines a lumen extending through the proximal portion to a side port located on the intermediate portion. The distal portion includes a support region for leveraging against a wall of a superior vena cava (SVC) of the patient. An inner catheter is sized to slide within the lumen and out the side port. The inner catheter includes a distal curve configured to facilitate access to the internal jugular vein. A guidewire is sized to slide within a lumen of the inner catheter. The lumen and side port are configured to direct the inner catheter towards the entrance to the IJV when the outer catheter is inserted with the support region in place against the SVC. Methods of providing access to a patient&#39;s internal jugular vein through a subclavian vein.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is related to the following co-pending and co-owned applications: DUAL SPIRAL LEAD CONFIGURATIONS, filed on the same day and assigned Ser. No. ______; ELECTRODE CONFIGURATIONS FOR TRANSVASCULAR NERVE STIMULATION, filed on the same day and assigned Ser. No. ______; SPIRAL CONFIGURATIONS FOR INTRAVASCULAR LEAD STABILITY, filed on the same day and assigned Ser. No. ______; METHOD AND APPARATUS FOR DELIVERING A TRANSVASCULAR LEAD, filed on the same day and assigned Ser. No. ______; NEUROSTIMULATING LEAD HAVING A STENT-LIKE ANCHOR, filed on the same day and assigned Ser. No. ______; TRANSVASCULAR LEAD WITH PROXIMAL FORCE RELIEF, filed on the same day and assigned Ser. No. ______; and METHOD AND APPARATUS FOR DIRECT DELIVERY OF TRANSVASCULAR LEAD, filed on the same day and assigned Ser. No. ______, all herein incorporated by reference in their entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention relates to delivery systems for medical electrical leads for nerve or muscle stimulation. The present invention more particularly relates to delivery systems and methods of providing access to a patient&#39;s internal jugular vein and adjacent to a vagus nerve. 
       BACKGROUND 
       [0003]    A significant amount of research has been directed both to the direct and indirect stimulation of nerves including the left and right vagus nerves, the sympathetic and parasympathetic nerves, the phrenic nerve, the sacral nerve, and the cavernous nerve to treat a wide variety of medical, psychiatric, and neurological disorders or conditions. More recently, stimulation of the vagus nerve has been proposed as a method for treating various heart conditions, including heart failure. Heart failure is a cardiac condition characterized by a deficiency in the ability of the heart to pump blood throughout the body and high filling pressure causing pulmonary fluid to build up in the lungs. 
         [0004]    Typically, nerve stimulating electrodes are cuff- or impalement-type electrodes placed in direct contact with the nerve to be stimulated. These electrodes require surgical implantation and can cause irreversible nerve damage due to swelling or direct mechanical damage to the nerve. A less invasive approach is to stimulate the nerve through an adjacent vessel using an intravascular lead. A lead including one or more electrodes is inserted into a patient&#39;s vasculature and delivered to a site within a vessel adjacent a nerve to be stimulated. 
         [0005]    Standard delivery systems exist for delivering medical electrical leads to regions in or near the heart. Problems can arise, however, when using standard delivery systems to deliver a medical electrical lead into a patient&#39;s vasculature for the purposes of nerve stimulation. One such problem occurs when a guide catheter or guidewire prolapses into the superior vena cava when attempting to access an internal jugular vein from a subclavian vein. Thus, there is a need in the art for a system for delivering a medical electrical lead into the internal jugular vein from a subclavian vein that avoids catheter or guidewire prolapse into the superior vena cava. 
       SUMMARY 
       [0006]    In one embodiment, the present invention is a lead delivery system for implanting a lead in a patient&#39;s internal jugular vein (IJV) through a subclavian vein. The system comprises an outer catheter having a distal portion, an intermediate portion, and a proximal portion. The outer catheter defines a lumen extending through the proximal portion to a side port located on the intermediate portion. The distal portion includes a support region for leveraging against a wall of a superior vena cava (SVC) of the patient. An inner catheter is sized to slide within the lumen and out the side port. The inner catheter includes a distal curve configured to facilitate access to the IJV. A guidewire is sized to slide within a lumen of the inner catheter. The lumen and side port are configured to direct the inner catheter towards an entrance to the IJV when the outer catheter is inserted with the support region in place against the SVC. 
         [0007]    In another embodiment, the present invention is a method of providing access to a patient&#39;s internal jugular vein (IJV) through a subclavian vein. The method comprises advancing an outer catheter into the subclavian vein. The outer catheter extends from a distal portion to a proximal portion and includes a side port providing access to a lumen of the outer catheter. The side port is aligned with an entrance to the IJV. An inner catheter is advanced through the outer catheter and out the side port to a desired location. A guidewire is advanced through the inner catheter into the IJV. 
         [0008]    In another embodiment, the present invention is a method of providing access to a patient&#39;s internal jugular vein (IJV) through a subclavian vein. The method comprises advancing an outer catheter into the subclavian vein. The outer catheter extends from a distal portion to a proximal portion and includes a side port providing access to a lumen of the outer catheter. The side port is aligned with an entrance to the IJV. A guidewire is advanced through the side port into the internal jugular vein. 
         [0009]    While multiple embodiments are disclosed, still other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  shows a schematic view of a patient&#39;s upper torso. 
           [0011]      FIGS. 2A-2C  show side views of outer catheters for use in a delivery system according to one embodiment of the present invention. 
           [0012]      FIG. 3  shows a side view of an inner catheter for use in a delivery system according to one embodiment of the present invention. 
           [0013]      FIG. 4  shows a side view of a guidewire for use in a delivery system according to one embodiment of the present invention. 
           [0014]      FIG. 5  shows a schematic view of an outer catheter, an inner catheter, and a guidewire located within a subclavian vein according to one embodiment of the present invention. 
           [0015]      FIG. 6  shows a schematic view of an outer catheter, an inner catheter, and a guidewire after advancement of the guidewire into an internal jugular vein according to one embodiment of the present invention. 
           [0016]      FIG. 7  shows a schematic view of outer catheter, an inner catheter, and a guidewire after advancement of the inner catheter into an internal jugular vein according to one embodiment of the present invention. 
           [0017]      FIG. 8  is a flowchart illustrating an exemplary method of implanting a medical electrical lead into the internal jugular vein according to one embodiment of the present invention. 
           [0018]      FIG. 9  shows a schematic view of outer catheter and a guidewire after advancement of the guidewire into an internal jugular vein according to one embodiment of the present invention. 
           [0019]      FIG. 10  shows a schematic view of an inner catheter advanced over a guidewire into the internal jugular vein according to one embodiment of the present invention. 
           [0020]      FIG. 11  is a flowchart illustrating an exemplary method of implanting a medical electrical lead into the internal jugular vein according to one embodiment of the present invention. 
       
    
    
       [0021]    While the invention is amenable to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail below. The intention, however, is not to limit the invention to the particular embodiments described. On the contrary, the invention is intended to cover all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the appended claims. 
       DETAILED DESCRIPTION 
       [0022]      FIG. 1  shows a partial cutaway view of a patient&#39;s upper torso, including a heart  10  and the veins of the neck  12  and thorax  14 . The subclavian veins  16  drain blood from the arms  18 . The internal jugular veins  20  drain blood from the head  22  and join the subclavian veins  16  to form the brachiocephalic or innominate veins  24 . The union of the brachiocephalic veins  24  forms the superior vena cava  26 , which returns blood from the head  22 , neck  12 , arms  18 , and thorax  14  to the right atrium  28 . A vagus nerve  30  is adjacent to the right internal jugular vein  20 . Another vagus nerve (not shown) is adjacent to the left internal jugular vein  20 . A stimulating device  32  is located in a subcutaneous pocket near the patient&#39;s subclavian vein. The stimulating device  32  is connected to a medical electrical lead  34  extending through the patient&#39;s subclavian, brachiocephalic, and internal jugular veins. In the illustrated embodiment, the lead  34  includes a retaining structure  35  positioned in the internal jugular vein  20 . 
         [0023]    In one embodiment, the medical electrical lead  34  has the form disclosed in U.S. patent application Ser. No. ______, filed ______, ______, 2007, entitled SPIRAL CONFIGURATIONS FOR INTRAVASCULAR LEAD STABILITY, above-incorporated by reference in its entirety. In an alternative embodiment, the medical electrical lead  34  has the form of a dual spiral as disclosed in U.S. patent application Ser. No. ______, filed ______, ______, 2007, entitled DUAL SPIRAL LEAD CONFIGURATIONS, above-incorporated by reference in its entirety. In another embodiment, the medical electrical lead  34  has the form disclosed in U.S. patent application Ser. No. ______, filed ______, ______, 2007, entitled NEUROSTIMULATING LEAD HAVING A STENT-LIKE ANCHOR, above-incorporated by reference in its entirety. 
         [0024]    In one embodiment, the stimulating device  32  includes an electrode (not shown) that provides electrical stimulation to a nerve. In one embodiment, the electrode provides electrical stimulation to a vagus nerve  30 . In another embodiment, the electrode has the form disclosed in U.S. patent application Ser. No. ______, filed ______, ______, 2007, entitled ELECTRODE CONFIGURATIONS FOR TRANSVASCULAR NERVE STIMULATION, above-incorporated by reference in its entirety. 
         [0025]      FIG. 2A  shows a side view of an outer catheter  40  according to one embodiment of the present invention. The outer catheter  40  has a lumen  42 , a proximal portion  44 , and a distal portion  46 . The lumen  42  extends from the proximal portion  44  to a side port  48 , which provides access to the lumen  42 . In the embodiment illustrated in  FIG. 2A , the outer catheter  40  also includes a guiding feature  47  located near the side port  48 . In one embodiment, the guiding feature  47  is a ramp. In other embodiments, the guiding feature  47  has any other shape adapted to guide a catheter or guidewire through the lumen  42 , out the side port  48 , and into the internal jugular vein  20 . In the embodiment illustrated in  FIG. 2A , the outer catheter  40  is generally J-shaped. The outer catheter  40  includes an intermediate portion  50  having an angle A 1  extending from the side port  48  to a distal tip  49 . In one embodiment, the angle A 1  is between approximately  91  and approximately  180  degrees. The intermediate portion  50  includes a support region  51 , which engages a wall  27  of the superior vena cava  26  when the outer catheter  40  is inserted into the subclavian vein  16  (as shown in  FIG. 5 ). In the embodiment shown in  FIG. 2A , the outside wall of the intermediate portion  50  is the support region  51 . In another embodiment, the support region  51  engages a wall of the brachiocephalic vein  24 . 
         [0026]      FIG. 2B  illustrates an outer catheter  40  according to another embodiment of the present invention. The outer catheter  40  includes an intermediate portion  50  having an angle A 1  extending from the side port  48  to the distal tip  49 . In the embodiment illustrated in  FIG. 2B , the angle A 1  is between approximately 1 and approximately 90 degrees. The outer catheter  40  includes a drop-down portion extending from the intermediate portion  50  to the distal tip  49 . The drop-down portion  52  is sized to extend into the superior vena cava  26  when the outer catheter  40  is advanced into the brachiocephalic vein  24  and includes a support region  51  that engages a superior vena cava wall  27  when the outer catheter  40  is located into the subclavian vein  16 . In one embodiment, the drop-down portion  52  has a length between approximately 1 and approximately 8 centimeters.  FIG. 2C  illustrates an outer catheter  40  according to yet another embodiment of the present invention. The outer catheter  40  includes an intermediate portion  50  that is substantially straight. In the embodiment shown in  FIG. 2C , the support region  51  for engaging the superior vena cava wall  27  is the distal portion  46 . In another embodiment, the outer catheter  40  includes a series of curves. In yet another embodiment, the outer catheter  40  includes an S-shaped series of curves. 
         [0027]    In the embodiments illustrated in  FIGS. 2A-2C , the outer catheter  40  has a solid cross-section from the guiding feature  47  to the distal tip  49 . In other embodiments, the region between the guiding feature  47  and the distal tip  49  includes a lumen (not shown). In one embodiment, the side port  48  has a diameter substantially equivalent to the diameter of the lumen  42 . In one embodiment, the outer catheter  40  has a length between approximately 20 and approximately 40 centimeters. In one embodiment, the outer catheter  40  has an outer diameter between approximately 6 and approximately 14 French, and an inner diameter slightly less than the outer diameter. 
         [0028]    In another embodiment, the angle A 1 , length of the outer catheter, location of the side port  48 , dimensions of the intermediate portion  40 , and other characteristics of the outer catheter  40  are selected based on the patient&#39;s anatomy such that the support region  51  engages the superior vena cava wall  27  to align the side port  48  with the entrance of a brachiocephalic vein  24  when the outer catheter  40  is located in the subclavian vein  16 . In another embodiment, the characteristics of the outer catheter  40  are selected to align the side port  48  with the entrance of a brachiocephalic vein  24  when inserted in a subclavian vein  16  without engaging a support region  51  with the wall  27  of the superior vena cava  26 . This alignment prevents prolapse of a guidewire  70  or inner catheter  60  into the superior vena cava  26 . The alignment of the side port  48  with the entrance of the brachiocephalic vein  24  also aligns the side port  48  with the entrance to the internal jugular vein  20 . In yet another embodiment, where the implantation is a “same side” implantation, the location of the side port  48  is selected so that the side port  48  is directly aligned with the entrance to the internal jugular vein  20  and the inner catheter directly accesses the internal jugular vein  20  from the subclavian vein  16 . 
         [0029]      FIG. 3  illustrates an inner catheter  60  according to one embodiment of the present invention. The inner catheter  60  includes a lumen  62 , which extends from a proximal portion  64  to a distal portion  66 . In one embodiment, the inner catheter  60  has a length between approximately 30 and approximately 80 centimeters. The inner catheter  60  has an outer diameter that allows it to slide within the lumen  42  and out the side port  48  of the outer catheter  40 . In one embodiment, the inner catheter has an outer diameter between approximately 4 and approximately 12 French, and an inner diameter slightly less than the outer diameter. In the embodiment shown in  FIG. 3 , the inner catheter  60  has a curve  68  near its distal portion  66 . In one embodiment, the curve  68  has an angle A 2  between approximately 40 and approximately 120 degrees, and is located between approximately 1 and approximately 2 centimeters from a distal tip  69  of the inner catheter  60 . In other embodiments, the inner catheter  60  does not have a curve. 
         [0030]    The inner and outer catheters  40 ,  60  can be made of a polytetrafluoroethylene (PTFE) or fluoronated ethylene propylene (FEP) inner lining, a 304 V stainless steel braiding, and an outer jacket of Pebax and/or Nylon. Tungsten wire can optionally be added to the stainless steel braiding to improve radiopacity of the catheter. In other embodiments, the inner and outer catheters  60 ,  40  are comprised of any other material known in the art. 
         [0031]      FIG. 4  depicts a guidewire  70  according to one embodiment of the present invention. In the illustrated embodiment, the guidewire  70  includes a body  74  and a distal tip  76 . The guidewire  70  allows a clinician to introduce and position a catheter or a medical electrical lead  34  in a patient. In one embodiment, the guidewire  70  has a core (not shown) and includes a coating, such as a hydrophilic coating. The guidewire  70  has an outer diameter that allows it to slide within the lumen  62  of the inner catheter  60 . In one embodiment, the outer diameter is between approximately 0.012 and approximately 0.040 inch. In one embodiment, the length of the guidewire  70  is between approximately 100 and approximately 250 centimeters. The guidewire  70  is shown as substantially straight in  FIG. 4 , but can have a J shape in other embodiments. In one embodiment, the distal tip  76  is an atraumatic tip. 
         [0032]      FIG. 5  is a schematic view showing the outer catheter  40 , inner catheter  60 , and guidewire  70  located in the subclavian vein  16 . In the illustrated embodiment, the outer catheter  40  is positioned in the left subclavian vein  16   a  to facilitate implantation of a medical electrical lead  34  in the opposite, or right, internal jugular vein  20   b . Although the method of implantation is described with respect to the left subclavian vein  16   a  and right internal jugular vein  20   b , in other embodiments, the method is used to implant a medical electrical lead  34  in the left internal jugular vein  20   a  from the right subclavian vein  16   b . In other embodiments, the method of implantation is a “same side” implantation from the right subclavian vein  16   b  into the right internal jugular vein  20   b , or the left subclavian vein  16   a  into the left internal jugular vein  20   a . In one embodiment, the outer catheter  40  is inserted into the left subclavian vein  16   a  using a percutaneous venipuncture. In an alternative embodiment, the outer catheter  40  could be inserted using a surgical cut-down to the subclavian vein  16  from a subcutaneous pocket (not shown) created for stimulating device  32 , or in any other manner as is known in the art. 
         [0033]    In the embodiment shown in  FIG. 5 , the outer catheter  40  is advanced through the left subclavian vein  16   a  so that the side port  48  is aligned with the entrance  80  to the right brachiocephalic vein  24 b from the superior vena cava  26 . Although the outer catheter  40  is shown as generally J-shaped in  FIG. 5 , in other embodiments, other outer catheter  40  configurations are used. The side port  48  prevents the inner catheter  60  and the guidewire  70  from prolapsing into the superior vena cava  26  during implantation. The intermediate portion  50  and the engagement of the outer catheter support region  51  with the superior vena cava wall  27  facilitate this alignment. The support region  51  is leveraged against the superior vena cava wall  27  and closes any gap between the support region  51  and the superior vena cava wall  27 . In the illustrated embodiment, the lumen  42 , the side port  48 , and the guiding feature  47  guide the inner catheter  60  and the guidewire  70  out of the side port  48  and into the internal jugular vein  20   b . The inner catheter curve  68  directs the guidewire  70  into the internal jugular vein  20   b . 
         [0034]    As shown in  FIG. 5 , the outer catheter  40  has a solid cross-section from the guiding feature  47  to the distal tip  49 , thereby preventing the guidewire  70  from passing out the distal tip  49  into the superior vena cava  26 . The distal tip  49  may be soft or atraumatic to avoid damaging the blood vessels during the implantation process. In one embodiment, the region between the distal tip  49  and the side port  48  is soft or atraumatic. In one embodiment, the distal tip  49  may be radiopaque to facilitate alignment of the side port  48  with the entrance  80 .  FIG. 6  is a schematic view showing the guidewire  70  after advancement through the lumen  62  of the inner catheter  60  to a suitable location in the right internal jugular vein  20   b . In alterative embodiments, the guidewire  70  is advanced to any desired location in the vasculature.  FIG. 7  is a schematic view of the inner catheter  60  when advanced over the guidewire  70  into the right internal jugular vein  20   b.    
         [0035]      FIG. 8  is a flowchart illustrating an exemplary method  800  of implanting a medical electrical lead  34  in an internal jugular vein  20  from a subclavian vein  16  using an outer catheter  40 , an inner catheter  60 , and a guidewire  70 . The outer catheter  40  is inserted into the subclavian vein  16  (block  810 ). The side port  48  is aligned with the entrance  80  to the brachiocephalic vein  24  from the superior vena cava  26  (block  820 ). The outer catheter  40  can be secured in the subclavian vein  16  using a suture or in any other manner as is known in the art. The inner catheter  60  is advanced through the outer catheter  40  to a desired location (block  830 ). In one embodiment, the desired location is in the brachiocephalic vein  24 . In another embodiment, the desired location is in the internal jugular vein  20 . In one embodiment, a guiding feature  47  is used to guide the inner catheter  60  out of the side port  48  and to the desired location. In one embodiment, the inner catheter  60  is advanced over the guidewire  70  and through the lumen  42  to the desired location. In another embodiment, the inner catheter  60  is advanced to the desired location and the guidewire  70  then advanced through the inner catheter  60  to the desired location. Next, the guidewire  70  is advanced through the inner catheter  60  so that the guidewire tip  76  reaches a suitable location in the internal jugular vein  20  (block  840 ). A medical electrical lead  34  is then advanced through the inner catheter  60  to a target location in the internal jugular vein  20  (block  850 ). 
         [0036]    In one embodiment, the medical electrical lead  34  includes a lumen and is advanced over the guidewire  70 . In one embodiment, after the guidewire  70  is advanced through the inner catheter  60  to the suitable location in the internal jugular vein  20 , the inner catheter  60  is advanced over the guidewire  70  from a desired location in the brachiocephalic vein  24  into the internal jugular vein  20 . In another embodiment, the outer catheter  40  is removed after the guidewire  70  reaches a suitable location and the medical electrical lead  34  is advanced through the inner catheter  60  to a target location. In yet another embodiment, the outer catheter  40  is removed and a third catheter (not shown) advanced over the inner catheter  60 . The inner catheter  60  is then removed and the medical electrical lead  34  is advanced through the third catheter to the target location. In other embodiments, venograms are taken through either the inner catheter  60  or the outer catheter  40 . In one embodiment, a contrast fluid or contrast fluid/saline mixture is injected into the proximal portion  44  of the outer catheter  40  and exits through the side port  48 , thereby allowing a clinician to visualize the anatomy using a venogram. In another embodiment, the implantation is a “same side” implantation and the outer catheter  40  is inserted into the subclavian vein  16  so that the side port  48  is directly aligned with the entrance to the internal jugular vein  20  and the inner catheter directly accesses the internal jugular vein  20  from the subclavian vein  16 . 
         [0037]      FIG. 9  illustrates an outer catheter  40  having a substantially straight intermediate portion  50  inserted into the left subclavian vein  16   a  and advanced so that the side port  48  is aligned with the entrance  80  to the right brachiocephalic vein  24 b from the superior vena cava  26 . The outer catheter  40  shown in  FIG. 9  has an intermediate portion  50  that is initially substantially straight. As shown in  FIG. 9 , when the distal tip  49  reaches the superior vena cava wall  27 , the distal portion  46  bends and the support region  51  engages the superior vena cava wall  27 , thereby aligning the side port  48  with the entrance  80 . The guidewire  70  is inserted through the lumen  42  of the outer catheter  40  and out the side port  48  so that the guidewire distal tip  76  reaches a suitable location in the right internal jugular vein  20   b . As shown in  FIG. 10 , the inner catheter  60  is advanced over the guidewire  70  through the lumen, and out the side port  48  to a desired location in the right internal jugular vein  20   b . The medical electrical lead  34  can then be advanced through the inner catheter  60  to a target location in the right internal jugular vein  20   b  using a variety of techniques. 
         [0038]      FIG. 11  is a flowchart illustrating an exemplary method  1100  for implanting a medical electrical lead  34  in an internal jugular vein  20  from a subclavian vein  16  using an outer catheter  40  and a guidewire  70 . The outer catheter  40  is inserted into the subclavian vein  16  (block  1110 ). The side port  48  is aligned with the entrance  80  to the brachiocephalic vein  24  from the superior vena cava  26  (block  1120 ). The guidewire  70  is advanced through the outer catheter  40  so that the tip  76  reaches a suitable location in the internal jugular vein  20  (block  1130 ). A medical electrical lead  34  is advanced over the guidewire  70  to a target location in the internal jugular vein  20  (block  1140 ). 
         [0039]    In another embodiment, after the guidewire  70  is advanced into the internal jugular vein  20 , an inner catheter  60  is advanced over the guidewire  70  to a desired location in the internal jugular vein  20 . In yet another alternative embodiment, a guiding feature  47  is used to guide the inner catheter  60  or the guidewire  70  out of the side port  48 . In one embodiment, the inner catheter  60  does not have a curve and the brachiocephalic vein  24  accommodates the configuration of the inner catheter  60  as needed. The medical electrical lead  34  is then implanted through the inner catheter  60 . In yet another alternative embodiment, the outer catheter  40  is removed before the medical electrical lead  34  is advanced to the target location. In another embodiment, the implantation is a “same side” implantation and the outer catheter  40  is inserted into the subclavian vein  16  so that so that the side port  48  is directly aligned with the entrance to the internal jugular vein  20  and the inner catheter directly accesses the internal jugular vein  20  from the subclavian vein  16 . In other embodiments, venograms are taken through either the inner catheter  60  or the outer catheter  40 . In one embodiment, a contrast fluid or contrast fluid/saline mixture is injected into the proximal portion  44  of the outer catheter  40  and exits through the side port  48 , thereby allowing a clinician to visualize the anatomy using a venogram. 
         [0040]    The invention facilitates orientation of the lead  34  and an electrode (not shown) within the internal jugular vein  20 . In one embodiment, when the guidewire  70  is inserted into the lead  34 , the guidewire  70  reduces the force exerted by the retaining structure  35  on a surface external to the retaining structure, for example, the outer catheter  40 , the inner catheter  60 , or the internal jugular vein  20 , thereby facilitating advancement and orientation of the lead  34 . In another embodiment, when a portion of the retaining structure  35  remains in the outer catheter  40  or the inner catheter  60 , the outer or inner catheter  40 ,  60  is used to rotate the lead  34  and position the electrode proximal to a vagus nerve  30 . 
         [0041]    Various modifications and additions can be made to the exemplary embodiments discussed without departing from the scope of the present invention. For example, while the embodiments described above refer to particular features, the scope of this invention also includes embodiments having different combinations of features and embodiments that do not include all of the described features. Accordingly, the scope of the present invention is intended to embrace all such alternatives, modifications, and variations as fall within the scope of the claims, together with all equivalents thereof.