Abstract:
A pair of cooperating catheters are used together to provide rapid access to the Left heart for diagnostic or therapeutic interventions. The initial entry point for the catheter pair is the groin. The pair of catheters can be used to carry out an electrographic determination of the location of the Fossa Ovalis on the septum. Features on the Catheter system permit quick and reliable confirmation of the catheter location via echo or x-rays. Once across the septum the inner catheter is removed from the outer catheter and a standard intervention may be carried out through the lumen of the outer catheter.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    Many patients undergo diagnostic or interventional procedures in their left heart. For example a patient with atrial fibrillation may undergo an electrophysiological study inside the chambers of the left heart to determine the physical location of the source of the arrhythmia. This may require the use of electrophysiology (EP) catheters positioned in side the left heart and in contact with the walls of the heart to make electrical measurements to determine the location and propagation properties of the arrhythmia. In some instances a particular location may be an anatomic defect that can be ablated by yet another catheter system. In a similar fashion a patient may undergo left heart catheterization to receive a Left Atrial Appendage (LAA) Occlusion device that is placed in the LAA. 
         [0002]    Although these procedures are becoming routine there is a need to improve the devices that allow the physician to gain access to the left heart from the right side of the heart and the venous system. The present standard of care involves the use of a stiff straight catheter to reach the right atrium (RA) from an entry site in the leg near the groin. Typically the venous system is accessed in the groin via the familiar Seldinger procedure. With the conventional catheter placed in the RA a supplemental and exposed needle is advanced out of the conventional catheter and it is used to approach and pierce the septal wall dividing the right heart from the left heart. 
         [0003]    This technique is cumbersome, requires a substantial amount of fluoroscopic exposure to both the patent and the physician and is potentially dangerous of several reasons. 
         [0004]    At the conclusion of the intervention the conventional catheters are removed and the wound in the groin is treated. 
       SUMMARY OF THE INVENTION 
       [0005]    There are two outer catheters and one inner catheter described and claimed. The inner catheter may be used with either of the two outer catheters and these two combined or paired embodiments are shown and claimed. 
         [0006]    The inner catheter can be used with conventional catheters as well but is less effective and more cumbersome to use in that configuration. 
         [0007]    The paired catheters are useful for carrying out a method of finding and crossing the fossa ovalis and the method is described and claimed. 
         [0008]    The two pairs of interacting devices are referred to in the specification as “Guider with Lancer” in a first embodiment and “Flexor with Lancer” in a second embodiment. 
         [0009]    In either case the two devices are coupled together and used together to interact together to carry out steps in an electrographic location procedure or method. The inner catheter Lancer device is supported by its companion outer catheter and together they are used to electrically probe the septal wall surface to determine electrographically the location of the fossa ovalis (FO). The Lancer includes an echogenic piercing tip that may be deployed to extends from the distal tip for piecing the FO. The distal tip is sufficiently opaque to x-rays to be seen radiographically and reflective enough to be visualized using ultrasound. 
         [0010]    With the specific FO location identified electrographically and verified with another and different modality the Lancer device may be used cross the septum with a deployable needle. Once across the septum the Guider or Flexor may be advanced into the left heart and used to approach the walls of the left atrium. When a desirable location is reached the Lancer is uncoupled from the Guider or Flexor and Lancer is withdrawn from Guider or Flexor. 
         [0011]    Therefore in use the Guider device or Flexor device supports and places the encased Lancer device at the wall of the septum. By dragging the pair down the septal wall the FO is found with an electrographic electrode that collects EMG signal at the septum to locate the ideal location for crossing into the left heart. It is important to note that this procedure is carried out with the electrically conductive needle retracted. 
         [0012]    With the desired treatment location found the Lancer device remains stationary and the septum is punctured with the same device. Although complex electrically and electrographically it is quicker than the conventional blind probing that is the current state of the art. 
         [0013]    The common law trademarks Lancer, Flexor and Guider have been adopted to identify the electrographic, dilating crossing catheter Lancer, and the guiding catheters Flexor and Guider. The marks are owned by Rhythm Xience of Minneapolis, Minn. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  is a cross-section of inner catheter Lancer; 
           [0015]      FIG. 2  is a cross section of the distal tip of Lancer with the puncture element withdrawn; 
           [0016]      FIG. 3  is a cross section of the distal tip of Lancer with the puncture element deployed; 
           [0017]      FIG. 4  is a perspective view of the inner catheter Lancer coupled to exterior catheter Flexor; 
           [0018]      FIG. 5  is a top view of the outer catheter Flexor; 
           [0019]      FIG. 6  is bottom view of the outer catheter Flexor; 
           [0020]      FIG. 7  is a bottom view of the outer catheter Flexor; 
           [0021]      FIG. 8  is a cutaway view of the interior of Flexor; 
           [0022]      FIG. 9  is a cutaway view of the interior of Flexor; 
           [0023]      FIG. 10A  is a schematic view of the Flexor distal tip; 
           [0024]      FIG. 10B  is a schematic view of the Flexor distal tip; 
           [0025]      FIG. 10C  is a schematic view of the Flexor distal tip; 
           [0026]      FIG. 11  is a view of the exterior side view of the Flexor catheter; 
           [0027]      FIG. 12  is a perspective view of the Lancer coupled to the Guider; 
           [0028]      FIG. 13  is a cross section of the Guider; 
           [0029]      FIG. 14  shows the context of a step in the method; 
           [0030]      FIG. 15  shows the context of a step in the method; 
           [0031]      FIG. 16  shows the context of a step in the method; 
           [0032]      FIG. 17  shows the context of a step in the method; 
           [0033]      FIG. 18  shows the context of a step in the method; 
           [0034]      FIG. 19  shows the context of a step in the method; 
           [0035]      FIG. 20  shows the context of a step in the method; 
           [0036]      FIG. 21  shows the context of a step in the method; 
           [0037]      FIG. 22  shows the context of a step in the method; 
           [0038]      FIG. 23  shows steps in a method; and, 
           [0039]      FIG. 24  shows steps in a method. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0040]    The overall context of the invention will be described. 
         [0041]    The structural features of Guider will be described. 
         [0042]    The structural features of Flexor will be described. 
         [0043]    The structural features of Lancer will be described. 
         [0044]    The method of using Lancer with a companion device will be described. 
       Lancer Device 
       [0045]    The Lancer device is a device to perforate the septum of the heart and dilate that puncture. It is carried in the handle and adapted for sliding motion. It also has electrode connections and functions as a probing electrode. The Lancer device has an internal lumen that can support and carry a guide wire. This permits Lancer to follow over a guide wire. 
         [0046]    Turning to  FIG. 1  Lancer generally designated  100 . There is user interface handle  112 . A thumb operated slide  114  is carried in the handle  112  and adapted from sliding motion along the axis  116  of Lancer. In operation the thumb slide  114  forces a tang  118  to compress a spring  120  located along and concentric with the axis  116 . Motion of the thumb slide  114  toward the distal end of the lancer causes the electrode/needle distal assembly  125  ( FIG. 2 ) to emerge as identified at  126  ( FIG. 3 ) from the casing  122 , as seen in  FIG. 2  and  FIG. 3  respectively. 
         [0047]    The distal assembly has three important features. The hypo-tube  128  has series of laser-machined partially circumferential slits typified by slit  130  which cooperate together to render the distal tip assembly flexible in any direction or plane and be compliant with the shape of a companion catheter. The distal tip is cut to form a piercing tip  132 . This tip is electrically coupled via wire  134  to the connector generally designated  136 . The distal sheath casing  122  tapers to a small diameter seen near ref numeral  138 , This tapered shape serves as a dilation surface  138 . 
         [0048]      FIG. 4  shows the Lancer  100  coupled to the companion Flexor  200  device. In general the Lancer is carried within Flexor and they are moved together as a single unit. The Lancer is supported by Flexor and in general the Lancer stiffens the Flexor and functions in part as a stylet to help the operation of Flexor  200 . 
       Flexor Device 
       [0049]      FIG. 5  is a top view of the outer catheter Flexor  200  showing the appearance of the top of the handle  212 . The Flexor sheath  214  extends form the distal end of handle  212  while the control knob  216  is located near the proximal end of the handle. The control knob turns on a control axis  220  defined by axel  224  orthogonal to the Flexor axis  218 . 
         [0050]    In use the physician turns the control knob with his left hand and uses the thumb of the left hand to activate the control button  228 . When this button is depressed as depicted at ref numeral  230  the tooth  232  disengages from lock pinion gear  234 . In the depressed or activated state the motion of the knob is unlocked and the control knob may be turned to steer or flex the distal tip of the device. When released the tooth  232  urged by spring pressure of compression spring  221 . 
         [0051]      FIG. 8  and  FIG. 9  show a cutaway of the interior of the Flexor  200 . The pinion  234  engages both rack  236  and rack  238 . Rotation of the pinion  234  drives the racks, with each rack driven in the opposite direction. Cable anchors  242  and cable anchor  240  are moved with respect to each other providing traction to the pulls wires (not seen) that deflect the deflectable distal tip  244  through an arc in a plane. 
         [0052]      FIG. 10A  shows the deflectable distal tip  244  in its un-deflected state corresponding to the rack positions seen in  FIG. 9 .  9 .  FIG. 10B  shows the deflectable tip moving through a  180  arc driven by pull wire  246  and pull wire  248 , each connected to its respective cable anchor  240  or  242 . This curvature corresponds to the rack positions seen in  FIG. 8 .  FIG. 10 c    shows an intermediate position corresponding to a deflection of approximately 90 degrees. 
         [0053]      FIG. 11  shows a side view of the flexor depicting the recess  250  in the handle to educe the profile of the control knob  216 . 
         [0054]    The construction details of the invention as shown in the preceding figures are that the useable length of the distal tubular section shall be sufficient to reach from a patient&#39;s vascular insertion site, in the groin area, to the left atrium of their heart, typically 50 to 75 centimeters, but may be longer in taller patients. As is well known only the proximal and distal section of the catheters illustrated to facilitate disclosure of the invention and the inventive features in the most proximal and distal areas of the catheters. The inner diameter of the distal tubular section shall be sufficient to accommodate various catheter devices, typically 5 French (1.65 mm) to 12 French (3.96 mm). The distal tubular section shall be made of a medical grade polymer and may include wire braiding within its wall. The distal tubular section  210  shall have coatings or a biomimetic surface on its patient-contacting surfaces to provide lubricity and/or deter the formation of blood clots. The side port tube shall be made of a medical grade polymer and have an external length of approximately 5 to 20-centimeters. The mechanical deflection actuator may be configured as a rotatable wheel, rotatable coaxial collar, slide, or lever. The figures depict the control knob actuator  214  as a rotatable wheel, other actuation mechanism may be employed. 
       Guider Device 
       [0055]      FIG. 12  shows Guider  300  coupled to Lancer  100 .  FIG. 13  shows that Guider  300  provides a faired shaped section providing a torque handle  301  which forms a directional indication. The side port  310  does not cross the torque handle  301  and therefore does not interfere with the use of the torque handle  301 . This arrangement eliminates interference and entanglement with adjacent devices, and mitigates the risks of clot formation on the blood-contacting surfaces of the introducer. Also seen in this figure is the most proximal section of a guide wire  101 . 
         [0056]    Referring now to the invention in more detail, in  FIG. 13  there is shown the entire guiding vascular introducer device  300  comprised of a distal tubular section  310  that traverses through a proximal handle  314 . 
         [0057]    In further detail, still referring to the invention of  FIG. 13 , distal tubular section  310  has a curved tip section  312 . The handle  314  is further comprised of a side port tube  316 . The external part of the side port tube  316  is located at the distal end of the handle  312 . 
         [0058]    In the  FIG. 13  there is shown a strain relief  320  at the junction of the distal tubular section  310  and handle  314  as well as a canted pass-through aperture  318  for the side port tube  316  to enter the handle  314 . 
         [0059]    The construction details of the invention are selected such that the useable length of the distal tubular section  310 ; including its curved tip section  312 , shall be sufficient to reach from a patient&#39;s vascular insertion site, in the groin area, to the left atrium of their heart, typically 50 to 75 centimeters, but may be longer in taller patients. The inner diameter of the distal tubular section  310 , including its curved tip section  312 , shall be sufficient to accommodate various catheter devices, typically 5 French (1.65 mm) to 12 French 3.96 mm). The distal tubular section  310 , including its curved tip section  312 , shall be made of a medical grade polymer and may include wire braiding within its wall. The distal tubular section  310 , including its curved tip section  312 , shall have coatings on its patient-contacting surfaces to provide lubricity and/or deter the formation of blood clots. The side port tube  316  shall be made of a medical graced polymer and have an external length of approximately 5 to 20 centimeters. The handle  314  shall be a length sufficient to efficiently manipulate the introducer with the thumb and 3-5 fingers, typically between 3-5 centimeters. Furthermore, the handle  314  shall be of shape that provides an intuitive directional indicator that is in plane with the curved tip section  312 . One such shape is an inverted teardrop, as depicted in  FIG. 12 . The handle  314 , including the canted pass-through aperture  318 , shall be made of a medical grade thermoplastic such as polycarbonate, polyethylene, or nylon. 
         [0060]    Referring now to  FIG. 13  there is shown the handle  314 , distal tubular section  310 , side port tube  316 , strain relief  320 , canted pass-through aperture  318 , and catheter access port  322 . Of note, the side port tube  316  and distal tubular section  310  exit from the handle  314  in a parallel orientation. 
         [0061]    The construction details of the side port tube  116 , distal tubular section  110 , hemostasis valve housing  124  and mounting stem  118  shown in  FIG. 13  are now described. The hemostasis valve housing  324  and integral mounting stem  325  are made of a medical grade thermoplastic such as polycarbonate, polyethylene, or nylon. The distal tubular section  310  is connected to the hemostasis valve housing  324  via injection molding or medical grade adhesive. The entire valve housing  324  shall be contained internally within the handle  314 . The side port tube  316  is connected to the mounting stem  318  via medical grade adhesive. 
         [0062]    The advantages of the present invention include, without limitation, is that it allows the operator to efficiently torque the introducer during a procedure. Typically, the operator only has a small hemostasis valve housing to serve as a torque handle. Furthermore, by removing the side port tube from the primary area of device manipulation eliminates the risks of interfering with operation and entangling with, and possibly dislodging, an adjacent device. Finally, the addition of a biomimetic coating on the patient-contacting surfaces with mitigate the risks of thrombogenesis, or the production of blood clots, which may lead to such adverse effects as stroke, myocardial infarction, or pulmonary embolus, all of which may be fatal. 
         [0063]    In broad embodiment, the present invention is a guiding vascular introducer designed with an ergonomic torque handle with features that promote efficient and an improved safety profile. 
       Method of Use 
       [0064]    The stepwise sequence of use proceeds as follows:
       1. The physician uses the Seldinger procedure to gain access to the femoral vein with a conventional needle puncture.   2. A long guidewire is inserted through the needle and advanced under fluoroscopic guidance to the SVC.   3. Withdraw the needle over the wire leaving the wire in place.   4. The Lancer-Flexor or Lancer-Guilder is advanced into the wound and over the wire to the SVC.   5. Pull the GW into the Lancer.   6. Rotate the Lancer-Flexor or Lancer-Guider to point medial as to be perpendicular to the plane of the interarterial septum.   7. Connect the extension lead form Lancer to an EMG recording system to display unipolar signal from the distal tip of Lancer   8. While maintaining system alignment via monitoring fluoroscopic imaging, electro gram and optional ultrasound imaging to locate the fossa ovalis.   9. Once the fossa ovalis location has been confirmed hold the system securely and actuate the thumb lever to advance the puncture element through the fossa ovalis,   10. Optionally confirm presence in the left atrium via contrast injection of pressure recording, and advance the GW into the left atrium.   11. Release the thumb lever automatically retracting the puncture element under the force supplied by spring.   12. Advance system into the left atrium while monitoring the electro gram.   13. Holding the system securely release and uncouple Lancer and push sheath toward tip of Lancer.   14. With the Sheath near the wall of the atrium The Lancer is withdrawn form the sheath, and the sheath is aspirated and flushed with heparinized saline. The sheath is now placed for the desired intervention such as ablation or device placement.       
 
         [0079]      FIG. 14  shows a state during the method. In the figure the Lancer  100  extends beyond d the distal tip of the guiding sheath  214  in this instance of a Flexor device. The Flexor outer sheath  214  and Lancer  100  and the guidewire  101  move together to correspond to Steps  1  and  2  of  FIG. 23 . 
         [0080]      FIG. 15  shows a state in the method. In the figure the GW is retracted into the Lancer  100 . The system, Lancer  100  and flexor  200  are moved to gather and the distal tip of Lancer is dragged along the SVC to the high septal surface while recording a displaying the electro gram. A typical electro gram in this position is seen in  FIG. 16 , where the injury current is a response to the contact with the Lancer electrode. This corresponds to steps  5 ,  6  and  7  of  FIG. 23 . 
         [0081]      FIG. 17  shows continued motion of the catheter pair an electrographic at  FIG. 18 , and visual confirmation of the Lancer  100  at the fossa ovalis. 
         [0082]      FIG. 19  represents real time recording associated with the path depicted in  FIG. 17 . It is typical 1 for the time scale of the EMG recorder to preserve several seconds of EMG so that comparisons can be made over time by the physician. 
         [0083]      FIG. 22  shows the characteristic electro grams that will be sensed by Lancer-Flexor or Lancer-Guider as it navigates the left heart atrium. 
         [0084]      FIG. 20  and  FIG. 21  show the time domain representation of exploratory motions in side of the Left Atrium. 
         [0085]      FIG. 23  and  FIG. 24  show a flow chart of illustrative steps in the method.