Patent Publication Number: US-2009234321-A1

Title: Visualization of coronary vein procedure

Description:
I.  BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention pertains method and apparatus for visualizing procedures performed in a coronary vessel such as a coronary vein. 
     2. Description of the Prior Art 
     Angiography procedures are widely used for assessing patency of coronary arteries. These procedures may also be used for other purposes—for example, in stent placement or other procedures. In such a procedure, a contrast medium is injected into a coronary artery proximal to a suspected site of a coronary obstruction. 
     Procedures are also developed (or in development) for performing procedures in coronary veins such as the coronary sinus. By way of non-limiting example, such procedures include lead placement for bi-ventricular pacing and procedures such as those shown in U.S. Pat. No. 6,964,683 to Kowalsky et al. issued Nov. 15, 2005 and U.S. Pat. No. 6,966,926 to Mathis issued Nov. 22, 2005 for re-shaping a mitral valve. 
     As in coronary artery procedures, coronary vein procedures may include injecting of a contrast medium into the coronary vein to facilitate visualization of the procedure under fluoroscopy. 
     Contrast media may have significant health risks if permitted to flow systemically to the patient&#39;s organs. For example, renal dysfunction or failure may occur from such systemic delivery of a contrast media. Such failure is referred to as “contrast-induced nephropathy” or CIN. Schräder, “Contrast Media-Induced Renal Failure: And Overview”,  Journal of Interventional Cardiology,  Vol. 18, No. 6, pages 417-423 (2005). 
     A number of different techniques in catheter designs have been suggested for collecting contrast media. Examples of such are shown in U.S. Pat. No. 6,554,819 to Reich issued Apr. 29, 2003; U.S. Patent Application Publication No. US 2002/0099254 A1 to Movahed published Jul. 25, 2002; U.S. Patent Application Publication No. US 2005/0256441 A1 to Lotan et al., published Nov. 17, 2005, U.S. Patent Application Publication No. 2005/0124969 to Fitzgerald et al. published Jun. 9, 2005 and U.S. Patent Application Publication No. US 2006/0013772 A1 to LeWinter et al., published Jan. 19, 2006. A contrast removal system is also described in Michishita, et al. “A Novel Contrast Removal System From The Coronary Sinus Using An Absorbing Column During Coronary Angiography In A Porcine Model”,  Journal of the American College of Cardiology,  Vol. 47, No. 9 (2006). Collection catheters are well known for collecting blood or other fluids from blood vessels of a patient. For example, International Publication No. WO 2005/082440 A1 describes collection catheters for collecting blood from a coronary sinus or other coronary vein in a perfusion system. 
     II.  SUMMARY OF THE INVENTION 
     According to a preferred embodiment of the present invention, a method and apparatus are disclosed for visualization of a medical procedure to be performed in a coronary vessel (such as a coronary sinus) of a patient. The method includes the steps of: identifying a coronary vessel for a procedure and placing a catheter within the coronary vessel. The coronary vessel is occluded at a site proximal to a distal end of the catheter. A contrast medium is injected into the coronary vessel through the catheter distal end for visualization of the procedure within the coronary vessel. Following the procedure, the contrast medium is removed through the catheter distal end and occlusion of the coronary vessel is discontinued. 
    
    
     
       III.  BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic side elevation view of a catheter system according to the present invention; 
         FIG. 2  is a view of a proximal end of the catheter of  FIG. 1  showing an alternative embodiment; 
         FIG. 3  is a schematic side sectional view of a coronary sinus having a catheter according to the present invention placed in the coronary sinus and shown ejecting a contrast media into the coronary sinus; 
         FIG. 4  is the view of  FIG. 3  showing placement of a procedural tool within the coronary sinus following injection of the contrast media; 
         FIG. 5  is the view of  FIG. 3  showing withdrawal of the contrast media from the coronary sinus; 
         FIG. 6  is a cross-sectional view of a first embodiment of the catheter of the present invention; 
         FIG. 7  is a cross-sectional view of a second cross-sectional embodiment; 
         FIG. 8  is a cross-sectional view of a third cross-sectional embodiment; 
         FIG. 9  is a longitudinal sectional view of the catheter of  FIG. 6 ; 
         FIG. 10  is a longitudinal sectional view of the catheter of  FIG. 8 ; 
         FIG. 11  is a longitudinal sectional view of the catheter of  FIG. 7 ; 
         FIG. 12  is a end view of the catheter of  FIG. 9  showing a first alternative balloon embodiment shown in an inflated state; 
         FIG. 13  is the view of  FIG. 12  with the balloon shown in a deflated state; 
         FIG. 14  is the view of  FIG. 12  showing an alternative embodiment with multiple balloons shown in an inflated state; 
         FIG. 15  is the view of  FIG. 14  with balloons shown in deflated states; 
         FIG. 16  is a schematic side elevation view of an actuator system for the present invention; 
         FIG. 17  is an actuator for coordinated administration and removal of inflation fluid and contrast media; and 
         FIG. 18  is a graph illustrating sequence of action of the actuator of  FIG. 17 . 
     
    
    
     IV.  DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the several drawing figures in which identical elements are numbered identically throughout, a description of a preferred embodiment of the present invention will now be provided. 
       FIG. 1  shows a system  100  including a catheter  10  according to the present invention. In the preferred embodiment, the catheter  10  is used to inject a contrast media into a coronary sinus or other coronary vein. Following such injection, the catheter may be used for advancing medical procedure tools through a lumen of the catheter  10 . Such procedures may include lead placement for bi-ventricular pacing or measuring devices for mitral valve re-shaping, by way of non-exhaustive examples. Following such procedure, the catheter  10  is used to remove the injected contrast media from the coronary sinus. 
     The catheter  10  is a long flexible and hollow tubular member  10  which has an opening at the distal end  12  and proximal end  14 . The catheter  10  may be sized for delivery through a jugular vein of the patient or through a femoral access both of which are known in the art for accessing the coronary sinus.  FIG. 1  shows a preferred embodiment for a jugular access catheter  10 . 
     In a preferred embodiment a femoral access, catheter  10  will have a plurality of segments along its length of varying stiffness to facilitate advancement of the distal tip  12  into a coronary sinus of a patient. By way of non-limiting example, a first distal segment S 1  has an approximate length of about 75 mm and is relatively soft with a durometer of 35 D. The adjacent second segment S 2  has a representative length of about 50 mm and a hardness of 40 D. The next adjacent segment S 3  has a length of approximately 50 mm and a higher durometer of 55 D. The next adjacent segment S 4  has a length of approximately 50 mm and a decreased durometer of 40 D. The next adjacent segment S 5  has a length of approximately 50 mm and an increased durometer of 55 D. The most proximal length S 6  has a length of approximately 25 cm and a durometer of 63 D to 72 D. By way of non-limiting example, the catheter  10  can have a diameter of about 11 French (approximately 3.6 mm in diameter). 
     The proximal end  14  of the catheter  10  connects to two couplings  18  and  20 , in series. First coupling  18  has a side port  19  for connection to a source of gas (e.g., air, nitrogen or helium) or saline other inflation fluid as will be described. Second coupling  20  has a side port  21  for connection to a source of a contrast media as will be described. Each of the couplings  18  and  20  has central lumens communicating with the central lumen of the catheter  10  and exposed through a most proximal port  22 . 
     With reference to  FIGS. 6 and 9 , the catheter  10  is shown in a first embodiment. The catheter  10  has a central lumen  24  which is exposed through the distal tip  12 . The lumen  24  is also exposed through the couplings  18  and  20  and through port  22  of  FIG. 1 . An inflation lumen  26  is formed in the side wall of the catheter and extends from the side port  19  of  FIG. 1  to communicate with the interior of the balloon  16  as shown in  FIG. 9 . 
     Referring back to  FIG. 1 , the system  100  includes at least first and second fluid administrators  30 ,  40 . In the preferred embodiment, the fluid administrators  30 ,  40  are shown as syringes including cylindrical bodies  31 ,  41  for retaining a fluid and plungers  32 ,  42  actuated by external members  34 ,  44  for movement of the plungers  32 ,  42  toward discharge ports  36 ,  46 . In a most preferred embodiment, the syringes  30 ,  40  are fixed to one another in side-by-side relation as shown in  FIG. 1  for ease of use. In all figures, syringes  30 ,  40  are not to scale. For example, only a few cubic centimeters (e.g., 6 cm) of gas may be need to inflate a balloon. Several hundred cubic centimeters of contrast media may be used. 
     Discharge port  36  is connected via tubing  50  to side port  19  of coupling  18 . Discharge port  46  is connected via tubing  52  to side port  21  of coupling  20 . The discharge port  46  includes an optional valve  60 . In a first position, valve  60  establishes a fluid flow path between port  46  and tubing  52 . In a second position, valve  60  establishes a fluid flow path between port  46  and tubing  62 . In a third position, valve  60  establishes a fluid flow path between port  46  and tubing  63  connected to a reservoir  65  of fresh contrast media. 
     In the preferred embodiment, syringe  30  contains a fluid for inflation of balloon  16 . In a most preferred embodiment, the inflation fluid is a saline or gas. At the start of a procedure, valve  60  is in the third position such that fresh contrast from reservoir  65  is drawn into syringe  40 , in which syringe  40  contains a contrast medium. 
     In use, the catheter is advanced through the patient&#39;s vasculature until the distal end  12  resides within a coronary sinus as illustrated in  FIG. 3 . Plunger  32  is then depressed causing the inflation fluid to be urged through inflation lumen  26  into the balloon  16  causing inflation of the balloon  16 . Inflation of the balloon  16  results in opposing surface of the balloon  16  abutting and sealing against the coronary sinus CS thereby occluding the coronary sinus CS. Following such occlusion, valve  60  is moved to the first position and plunger  40  is depressed to inject a contrast medium CM into the coronary sinus as illustrated in  FIG. 3 . With the contrast medium CM in the coronary sinus CS, the area of interest of the coronary sinus CS can be visualized under fluoroscopy. 
     With the contrast medium CM within the coronary sinus CS, procedure tools (such as lead delivery devices or measuring devices) may be advanced through the central lumen  24  by passing the procedural device PD through the proximal port  22 , through the central lumen  24  and then through the distal end  12  as illustrated in  FIG. 4 . The procedural device PD may be left in place or removed. In either event, the contrast medium CM may be removed from the coronary sinus CS by applying a suction to the central lumen  24  causing the contrast medium CM to flow into the catheter  10  ( FIG. 5 ). The suction is applied by drawing the plunger  42  away from port  46  so that the contrast medium is drawn through line  52 . In one embodiment, valve  60  is manipulated such that a suction is applied to port  46  and fluid (e.g., contrast with blood) drawn toward syringe  40  along tubing  52  is redirected through tubing  62  to a fluid reservoir  64 . 
     Since the recovered contrast medium CM may also contain biological hazards such as blood, the valve  60  can be shifted to the second position to move the used contrast medium from syringe  40  to reservoir  64  for subsequent disposal (or later use in the procedure if so desired). Following withdrawal of the contrast medium CM, the plunger  32  may be withdrawn thereby deflating the balloon  16  permitting removal of the catheter  10  from the patient. 
     Commonly, the contrast medium may be removed from the coronary sinus following visualization (venogram) and before insertion of the procedural device PD. Throughout the procedure, contrast medium can be injected or removed as desired. At the physician&#39;s option, the subsequently injected contrast medium may be fresh contrast from reservoir  65 . 
     As mentioned, the procedural device PD may be left in place in which case the catheter  10  must be withdrawn over the procedural device PD. In a most preferred embodiment, the catheter  10  is constructed to be split along its length to allow it to be withdrawn over a procedure device PD. 
     It will be appreciated that such catheters capable of splitting are known in the art and an example of such is the RAPIDO® Cut-Away® Guiding Catheters of Guidant Corporation, St. Paul, Minn. USA and described in their instructions for use PPL2043029 (Mar. 10, 2004). Such catheters have hubs which may be split open along a weak point formed in the hub. A blade is then used to split the catheter along its axial length. 
     Such prior art splitting catheters do not include balloons which can otherwise obstruct the splitting process.  FIGS. 12-15  show alternative designs for occlusion devices which facilitate the use of a splitting blade along the length of the catheter. 
     In  FIGS. 12 and 13 , a single balloon  16 ′ is shown surrounding the catheter  10 . The balloon  16 ′ is fixed to the catheter so that a portion  80  of the catheter is exposed when the balloon is deflated as shown in  FIG. 13 . The exposed portion  80  permits passing of blade through the catheter wall and splitting the catheter in the region of the balloon  16 ′. The balloon  16 ′ is pre-formed so that when inflated ( FIG. 12 ) the balloon  16 ′ completely surrounds the catheter  10 .  FIGS. 14-15  show an alternative embodiment including multiple balloons  16 ″ each with separate inflation lumens  26 . Deflated of the balloons  16 ″  FIG. 15 ) reveals exposed portions  80   b  of the catheter  10  for passing a splitting blade. When inflated ( FIG. 14 ), the balloons  16 ″ completely surround the catheter  10  to seal against the coronary sinus. 
       FIGS. 7 ,  8  and  11 ,  12  show alternative embodiments of the catheter  10 . In the embodiment of  FIGS. 7 and 11  the catheter  10   a  has a concentric inner tube  11   a.  The central lumen  24   a  resides within the inner tube  11   a.  Opposing surfaces of the inner tube  11   a  and outer tube  10   a  define an annular lumen  25   a.  An inflation lumen  26   a  resides within the wall of outer tube  10   a.  The inflation lumen  26   a  communicates with the interior of the balloon  16   a  and with side port  19 . The central lumen  24   a  communicates only with port  22  and is for passing procedural tools or guide wires or the like through the lumen  24   a.  The annular lumen  25   a  is connected through side port  21  to the contrast medium source  40 .  FIGS. 8 and 10  show a still alternative embodiment very similar to  FIG. 7  differing only in that the lumens  25   b  and  24   b  are not concentric but are otherwise as described with reference to  FIGS. 7 and 11 . 
     In the embodiments thus described, side port  19  acts to both admit and remove contrast media.  FIG. 2  shows a still alternative embodiment with a second side port  23  in fluid communication with contrast the media lumens  25   a  or  25   b  of  FIGS. 7 and 8 . Side port  21  is also in communication with the same lumens  25   a  or  25   b.  Accordingly, unlike the embodiment of  FIG. 1 , a separate suction device (not shown) can be used to withdraw used contrast media which may be contaminated with blood through side port  23  to a reservoir  64 . 
       FIG. 16  illustrates a still further embodiment modifying the syringe structure shown in  FIG. 1 . In the embodiment of  FIG. 16 , syringe  40  is used only to deliver fresh contrast media through a one-way check valve  43 . Fluid from the one-way check valve  43  passes into a Y-connector  51  having a port  51   a  connected to tubing  52  (of  FIG. 1 ). An opposite end of the Y-connector has second syringe  140  connected to the Y-connector  51  by a one-way check valve  143 . Check valve  43  permits admission of fluid from syringe  40  into the Y-connector  51 . Check valve  143  permits fluid flow from the Y-connector  51  into the syringe  140 . The Y-connector  51  is preloaded with saline S or the like. As shown, the syringe  140  is initially placed with the plunger  142  in a fully depressed state. With the structure thus described, syringe  40  is used to admit contrast media CM into line  52 . Syringe  140  is to withdraw fluid (used contrast media mixed with blood) from line  52  into syringe  140  without such withdrawn fluid contaminating fresh contrast media contained within syringe  40 . 
       FIG. 17  schematically illustrates a main actuator  200  for coordinated administration and removal of inflation fluid and contrast medium. The inflation cylinder  30  is connected to line  50 . The contrast medium injector  40  is connected to line  52  as in  FIG. 1 . The administrators  30 ,  40  are commonly housed in a housing  201 . The main actuator  200  includes a lever  203  connected to the housing  201  at a pivot point  204 . The lever  203  is depressed by an exposed depression mechanism  202 . The lever  203  is shaped and the administrators  30 ,  40  are housing in a staggered position such that upon depression of member  202 , the inflation actuator  30  is first actuated followed by a delay before actuation of the contrast medium actuator  40 . The reverse procedure occurs when the member  202  is withdrawn. Not shown in  FIG. 17  are springs for causing plungers  34 ,  44 , and  202  to be urged to the position shown in  FIG. 17 . 
       FIG. 18  shows the operation of the device of  FIG. 17 . The plunger  202  is depressed at times t 1 . This causes plunger  34  to depress without any corresponding action by plunger  44 . As a result, the balloon  16  is inflated during the stroke represented by the distance in the spacing between plunger  244  and the lever  203  at the rest position shown in  FIG. 17 . At time t 2 , the balloon  16  is fully inflated and the lever engages plunger  44  causing injection of contrast medium while maintaining the balloon  16  in an inflated state. At time t 3 , the user releases button  202  which permits the contrast medium to be withdrawn first while maintaining balloon inflation. After all the contrast medium is withdrawn at time t 4 , the balloon deflates. 
     Having described the present invention of the preferred embodiment, modifications and equivalents will become apparent to one of ordinary skill in the art. It is intended that such modifications and equivalents be included within the scope of the claims which are appended hereto.