Abstract:
An implantable line, in particular an electrode line and/or sensor line and/or medicine supply line for implantation in the left ventricle of the heart with perforation of the atrial or ventricular septum, includes an elongated flexible line body, an electrode and/or a sensor and/or a medicine administering device at or near the distal end of the line body, and a closure element integrally molded on the line body or connected thereto for sealing the perforation site in the septum.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention relates to an implantable line or line configuration for implantation in the left ventricle of the heart with perforation of the atrial or ventricular septum. 
       BACKGROUND OF THE INVENTION 
       [0002]    Implantation of an electrode in a left-ventricular vein via the coronary sinus is currently considered to be a state-of-the-art procedure for left-ventricular stimulation and detection. These so-called coronary sinus electrodes are used primarily for cardiac resynchronization therapy. 
         [0003]    The medical literature contains a growing number of case reports of transseptal implantation of left-ventricular stimulation electrodes for resynchronization therapy. These implantation techniques have always been implemented with the help of existing catheters, guide wires and electrodes. Puncture of either the atrial septum or the ventricular septum has been described for access to the left ventricle. See, for example, Transseptal Endocardial Left-Ventricular Pacing: An Alternative Technique for Coronary Sinus Lead Placement in Cardiac Resynchronization Therapy, B. M. van Gelder, M. G. Scheffer, A. Meijer, et al.,  Heart Rhythm  April 2007: 4(4):454-60. 
         [0004]    Furthermore, concepts for transmural left-ventricular pressure measurement are also currently being investigated in clinical trials wherein pressure sensors are placed transmurally in the left ventricle for permanent telemetric pressure monitoring in the left ventricle. See, e.g., www.transomamedical.com or the following technical publications: 
         [0005]    A Novel Technique for Assessing Load-Dependent Cardiac Function During LVAD Support Using Telemetered Left-Ventricular Pressure. P.  1 . McConnell, C. L. Del Rio, P. Kwiatkowski, D. Farrar, T. Shipkowitz, R. E. Michier, B. Sun,  ASAIO Journal  51(2): 31A, March/April 2005; 
         [0006]    In-Vivo Safety and Accuracy of a Clinically Applicable Telemetered Left-Ventricular Pressure Module: Intermediate-Term Results, P. I. McConnell, D. de Cunha, T. Shipkowitz, J. Van Hee, P. Long and R. Hamlin,  Heart Failure Society Meeting,  September 2004; 
         [0007]    A System for Long-Term Measurement of Left-Ventricular Pressure in Heart Failure Patients Living at Home, N. Sweitzer, S. Park,  Heart Failure Society Meeting,  September 2002; 
         [0008]    Automated Non-Invasive Monitoring of Left-Ventricular Hemodynamics During Onset of Heart Failure in an Ambulatory Yucatan Mini Pig Model Using a New System Under Development for Assessing Heart Failure Patients at Home, S. Park, N. Sweitzer,  Heart Failure Society Meeting,  September 2002; or 
         [0009]    A System for Long-Term Measurement of Left-Ventricular Pressure in Heart Failure Patients Living at Home, S. Park, N. Sweitzer and G. May,  Heart Failure  &amp;  Circulatory Support Summit,  Cleveland, Ohio, August 2002. 
         [0010]    A number of commercial closure systems are currently available for congenital atrial septal defects, open foramen or foramen ovale and ventricular septum defects (e.g., Premere™ PFO, SJM), which can be positioned via catheter techniques and which ensure a reliable closure of the septum defect. In this regard, see Transcatheter Patent Foramen Ovale Closure Using the Premere PFO Occlusion System, Andrea Donti, Alessandro Giardini, Luisa Salomone, Roberto Formigari, Fernando M. Picchio,  Catheterization and Cardiovascular Interventions,  vol. 68/5 2006. 
         [0011]    WO 2006/105395 A2 describes a transseptal/transmyocardial ventricular stimulation electrode. 
         [0012]    In approximately 10-15% of the implantations, anatomical conditions prohibit reliable implantation of a left-ventricular coronary sinus electrode. Furthermore, the incidence of dislocation of left-ventricular electrodes implanted for cardiac resynchronization therapy (CRT) by way of the coronary sinus is greater than that with a traditional right-ventricular pacemaker electrode. For these reasons, purely left-ventricular stimulation using a coronary sinus electrode is not currently being used for treatment of bradycardia or for implantation of automatic cardioverter/defibrillators (ICD), because neither the success nor the safety of implantation is guaranteed with this type of left-ventricular electrode. The very limited options for placement are another disadvantage of a coronary sinus electrode. In most cases, there are only one or two different positions for attachment of the probe. This is discussed as one of the primary causes of the poor responder rate (60-70%) of CRT at the present time. 
         [0013]    The techniques presented above for electrode implantation in the left ventricle via the atrial or ventricular septum are very complex and have not yet been successful because of the risks (RV shunt, thrombi). Free placement of the electrode in the left ventricle is possible here, and this would eliminate the disadvantages of attachment of the probe, the responder rate, and anatomical restrictions. 
         [0014]    Transluminal LV pressure measurement can be used for a system to permanently penetrate through the myocardium into the left ventricle. This introduces a very short probe into the left ventricle which has a pressure sensor and is of the type that cannot be used for electric stimulation of the heart. However, the probe described in WO 2006/105395 A2 is designed so that the active stimulation area lies only in the area of the left-ventricular septum and cannot be positioned freely in the left ventricle. In addition, WO 2006/105395 A2 does not discuss repositioning or the explantation ability of an electrode. 
       SUMMARY OF THE INVENTION 
       [0015]    To reduce the aforementioned disadvantages, an object of the present invention is to construct a left-ventricular probe that can be advanced from the right ventricle into the left ventricle through the atrial or ventricular septum, and which can be maneuvered freely and secured within the left ventricle, whereby the risk of implantation of a left-right shunt is is minimized through suitable design measures on the probe body. Furthermore, the possibility of repositioning such a probe and its explantation can be taken into account. 
         [0016]    This object is achieved by implantable lines and/or line configurations as defined by the accompanying claims. 
         [0017]    The invention provides a suitable element at the perforation site in the atrial or ventricular septum through which the electrode line is inserted, said line ensuring a reliable mutual seal of the areas of the heart adjacent to the septum, at least during the ingrowth phase. This can be accomplished by the electrode line itself, which then carries a suitable closure element. In other versions of the invention, a separate closure element is provided for this purpose, with the closure element being positioned before the insertion of the electrode line in the septum and then being punctured by the insertion of the electrode line. 
         [0018]    It is noted that the invention can also be used with a line and/or line configuration provided for use in the left atrium if the line is passed through the septum into the left atrium. 
         [0019]    An advantage of the invention is the secure and reliable access to the left ventricle without the anatomical restrictions of the coronary sinus access. With this technique, it is then possible to provide cardiac pacemakers, ICDs and CRT devices that are controlled primarily via the left ventricle. The advantages of primarily left-controlled systems include:
       physiologically more favorable stimulation site;   better sensing signals due to the larger muscle mass;   more favorable conditions for affixing the probe and a lower risk of perforation due to the greater wall thickness;   better possibilities of hemodynamic optimization by stimulation;   the disadvantage of RV stimulation is largely eliminated.       
 
         [0025]    In comparison with the known approaches, simple repositioning and explantation of the transseptal probe is also achieved when using the feed-through (“working channel”). 
         [0026]    The closure body can be fixedly connected to the electrode, so that longitudinal movement of the electrode body in the septum is prevented. 
         [0027]    In another version of the invention, the closure body is characterized as an expandable screen. 
         [0028]    In a similar version of the invention, the closure body is embodied as a first seal in the form of an expandable screen and as a second seal in the form of an expandable anchor that is displaceable on the electrode (proximally to the screen). 
         [0029]    The probe is preferably coated in the area of the closure body to promote rapid development of connective tissue in the area of the perforation site. 
         [0030]    The “working channel” preferably has a maximum free diameter of 2 mm when no electrode is pushed through it (acceptable left-right shunt). 
         [0031]    In another version of the invention, the “working channel” is characterized by X-ray markers and/or is made of a radiopaque material. 
         [0032]    The working channel is attached in the septum, e.g., by expandable fixators (e.g., stents). The LV probe may also be attached in the working channel by expandable fixators. These fixators are attached to the probe. The expandable fixators may also be used for unipolar and bipolar stimulation of the septum. 
     
    
     
       BRIEF DESCRIPTION OF THE INVENTION 
         [0033]    Advantages of the invention will also be apparent from the following description of exemplary versions of the invention and the associated drawings, wherein; 
           [0034]      FIG. 1  shows an overall view of a defibrillation configuration with an exemplary version of the invention, 
           [0035]      FIG. 2  shows an electrode line according to an exemplary of the invention, 
           [0036]      FIG. 3  shows an electrode line according to an alternative version of the invention, 
           [0037]      FIGS. 4   a  to  4   c  shows diagrams of another version of the invention in various phases of implementation, and 
           [0038]      FIG. 5  shows a detailed view of another version of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0039]      FIG. 1  shows an exemplary version of the invention.  1 . A left-ventricular electrode line  3  is advanced through an implantable transseptal feed-through (“working channel”)  5  into the left ventricle where it is affixed by means of a conventional screw  7 . In the embodiment shown here, the left-ventricular electrode line  3  has a bipolar stimulation electrode  9  and also has two shock electrodes (distal shock electrode  11  and proximal shock electrode  13 ). The diameter of the distal shock electrode is selected so that it cannot slip through the feed-through into the left ventricle. The line  3  is connected to an electrode plug  15  (e.g., types IS-4 and/or IS-1 and DF-1) with an implantable defibrillator  17 . 
         [0040]      FIG. 2  shows another version of the invention, specifically an electrode line  19 , which can be implanted by means of a guide wire  21  with a proximal handle  22  and whose design is essentially known in this field of technology, including a flexible electrode line body  23  (shown here bent into a U shape), a tip electrode  25 , and a distal fixation hook  27  for anchoring in the wall of the ventricle. However, this electrode line  19  includes a new feature in the form of a closure element  29  (represented here symbolically as two disk-like seals with a small distance between them) for closure of a perforation site in the septum through which the electrode line  19  (as shown in  FIG. 1 ) is guided into the left ventricle. 
         [0041]      FIG. 3  shows as a specific design of this embodiment an electrode line  19 ′ in which the closure element  29  is formed by two mutually spreadable screens  29   a ′,  29   b ′, which can be spread in opposite directions and, thanks to an additional control wire  30 ′, can be spread on both sides of the perforation site in the septum after insertion of the electrode line  19 ′, and in the spread state, can seal the electrode line  19 ′ from the environment of the puncture site. 
         [0042]    The proximal screen may additionally be pushed onto the probe by means of the additional s mandrel  30 ′, so that the ventricular septum is secured between the two screens. The two screens  29   a ′,  29   b ′ may also be used as active (e.g., bipolar) stimulation electrodes. 
         [0043]    The septal feed-through (“working channel”)  31  shown in  FIGS. 4A-C  is first created by means of a Brockenbrough needle  33  by puncture of the ventricular septum VS. The feed-through itself consists of two expandable stents  35   a ,  35   b  embedded in a flexible biocompatible tubing  35   c , e.g., silicone or polyurethane. This feed-through is mounted on an expandable balloon  37  of a balloon catheter  39  and is affixed in the septum by balloon expansion. 
         [0044]    To ensure the correct position of the feed-through, a second balloon  41  of a larger diameter is positioned on the balloon catheter, so that the balloon expands after puncture of the left ventricle and retraction of the Brockenbrough needle. Then the balloon catheter is retracted to such an extent that the larger balloon  41  contacts the ventricular septum VS. Next the feed-through  31 , the length L of which was determined in advance by echocardiography, is affixed by expansion of the smaller balloon  37  in that the expandable balloon  37  pushes the stents  35   a ,  35   b  with the length of tubing  35   c  between them against the wall of the hole in the septum formed by the Brockenbrough needle. 
         [0045]    After removal of the balloon catheter  39 , the feed-through  31  and optionally a guide wire  43  remain in the puncture site ( FIG. 4B ). The two stents  35   a ,  35   b  are visible in the X-ray image, so that subsequent navigation of the LV probe through this transseptal feed-through is readily possible. The left-right shunt volume is minimized by the flexible part of the feed-through  31 . If no line is inserted, the inside width d is reduced by an inward curvature of the flexible length of tubing  35   c  between the stents  35   a ,  35   b.    
         [0046]      FIG. 4C  shows the transseptal feed-through  31  described above together with a left-ventricular line and/or probe  45 . To avoid a longitudinal movement of the probe  45  within the transseptal feed-through, it can be attached by a self-expanding fixator  47  within the feed-through. In the exemplary embodiment, this fixator  47  is implemented as a radiopaque spring element, which is released by retraction of a tubing  49 , thereby securing the electrode line  45  in the feed-through. This prevents abrasion of the electrode line  45  or the fixator  47 . 
         [0047]    As an alternative to the LV probes described above in combination with a feed-through,  FIG. 5  shows an LV probe which can be attached independently without a separate closure element by means of expanding fixators  53  affixed directly in the septum, such that these s fixators  53  are first sheathed by a tubing  55  and then expanded by retracting this tubing by means of springs  57  in the septum VS. 
         [0048]    The tubing  55  is designed so that it can be removed completely from the electrode line  51  after implantation (e.g., by peeling). For the case of explantation of such an electrode line  51 , the fixators  53  can be “inserted” again by feeding corresponding tubing over the electrode line  51  and fixators  53  after cutting off the electrode plug. The fixators  53  may be used as active stimulation electrodes by connecting them to the electric feeder lines  57  of the electrode line  51 . Implantation in this line is likewise accomplished by using a Brockenbrough needle. 
         [0049]    The invention is not limited to the examples described above and the features emphasized here, but instead encompasses all forms and modifications encompassed by the claims below.