Abstract:
A device for percutaneously accessing the pericardial space has a tubular body wall enclosing a lumen. The wall ends in a tip that has an inferior aperture in fluid communication with the lumen. The tip surrounds and roofs over the aperture to form an chamber above the aperture, The portion of the tip over the aperture has a plurality of grooves in fluid communication with the lumen. The device includes a hollow body with a piercing end moveable in the first tubular body to extend into the chamber. A vacuum applied by the device to the chamber draws a bleb of pericardium into the chamber where it can be safely pierced by the piercing body to fain access to the pericardial space.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims under 35 U.S.C. §119(e) the benefit of U.S. Provisional Application 61/787,326 filed on Mar. 15, 2013, the content of which is incorporated in its entirety. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT 
       [0002]    Not Applicable 
       BACKGROUND OF THE DISCLOSURE 
       [0003]    1. Field of Disclosure 
         [0004]    This invention relates to methods and apparatus for accessing the pericardial space for medical treatment of the heart. 
         [0005]    2. Background 
         [0006]    Knowledge of the pericardium dates back to the time of Galen (129- 200 A.D.)  the Greek physician and anatomist who gave the pericardium its name. The pericardial sac surrounds the heart like a glove enfolds a hand, and the pericardial space is naturally fluid-filled. The normal pericardium functions to prevent dilatation of the chambers of the heart, lubricates the surfaces of the heart, and maintains the heart in a fixed geometric position. It also provides a barrier to the spread of infection from adjacent structures in the chest, and prevents the adhesion of surrounding tissues to the heart. See generally, Holt J P: The normal pericardium, Amer J Cardiol 26:455, 1970; Spodick D H:  Medical history of the pericardium,  Amer J Cardiol 26:447, 1970. The normal pericardial space is small in volume and the fluid film within it is too thin to functionally separate the heart from the pericardium. It has been observed that when fluid is injected into the pericardial space it accumulates in the atrioventricular and interventricular grooves, but not over the ventricular surfaces. 
         [0007]    Pericardiocentesis, or puncture of the pericardium, heretofore has been indicated for (1) diagnosis of pericardial disease(s) by study of the pericardial fluid, (2) withdrawal of pericardial fluid for the treatment of acute cardiac tamponade, (3) infusion of therapeutic agents for the treatment of malignant effusion or tumors and (4) infusion of stem cells for therapeutic treatment of the heart At present, intrapericardial injection of drugs is clinically limited to the treatment of abnormal pericardial conditions and diseases, such as malignant or local pericardial effusions and tumors. 
         [0008]    Intrapericardial drug delivery has not been clinically utilized for heart-specific treatments where pericardial pathology is normal, because the pericardial space is normally small and very difficult to access without invasive surgery or risk of cardiac injury by standard needle pericardiocentesis techniques. The pericardiocentesis procedure is carried out by experienced personnel in the cardiac catheterization laboratory, with equipment for fluoroscopy and monitoring of the electrocardiogram. Electrocardiographic monitoring of the procedure using the pericardial needle as an electrode is commonly employed. Complications associated with needle pericardiocentesis include laceration of a coronary artery or the right ventricle, perforation of the right atrium or ventricle, puncture of the stomach or colon, pneumothorax, arrhythmia, tamponade, hypotension, ventricular fibrillation, and death. The complication rates for needle pericardiocentesis are increased in situations where the pericardial space and fluid effusion volume is small (i.e., the pericardial size is more like normal). 
         [0009]    The described invention is a mechanism to achieve pericardial capture, puncture and therefore fluid access to the epicardium to undertake a variety of therapies and is an improvement over the devices described in patents: U.S. Pat. Nos. 5,827,216; 5,900,433; 6,162,195 and 6,666,844, the contents of which are incorporated in their entirety for background. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    In the following detailed description of exemplary embodiments, reference is made to the accompanying drawings, which form a part hereof and in which are shown by way of illustration examples of exemplary embodiments with which the invention may be practiced. In the drawings and descriptions, like or corresponding parts are marked throughout the specification and drawings with the same reference numerals. The drawings are not necessarily to scale. Certain features of the invention may be shown exaggerated in scale or in somewhat symbolic or schematic form and some details of conventional elements may not be shown in the interest of clarity and conciseness. Referring to the drawings: 
           [0011]      FIG. 1  is a general view of one end of one embodiment of the present invention. 
           [0012]      FIG. 2A  is an axial centerline sectional schematic view of an embodiment of an introducer tip of the present invention. 
           [0013]      FIG. 2B  is a front partially cross sectional schematic view of the tip of  FIG. 2A . 
           [0014]      FIG. 3  is an axial centerline sectional schematic view of the tip of  FIG. 2A  showing a needle and guidewire. 
           [0015]      FIG. 4A  is a side elevational partially axial sectional view of another embodiment of an introducer tip of the invention. 
           [0016]      FIG. 4B  is side elevational partially axial sectional schematic view of the embodiment of  FIG. 4A . 
           [0017]      FIG. 4C  is an end view of the embodiment of  FIG. 4A  as shown deployed in  FIG. 4B . 
           [0018]      FIG. 4D  is a bottom view of the embodiment of  FIG. 4A  as shown deployed in  FIG. 4B  showing a deployed needle. 
           [0019]      FIG. 5A  is an axial centerline sectional schematic view of another embodiment of an introducer tip of the invention. 
           [0020]      FIG. 5B  is a view of the proximal end of the invention and a view of associated electronics. 
           [0021]      FIG. 6A  is a view of the proximal end of another embodiment of the invention. 
           [0022]      FIG. 6B  is a schematic of another embodiment of the invention with the tip in an upward position. 
           [0023]      FIG. 6C  is a schematic of another embodiment of the invention with the tip in a downward position. 
           [0024]      FIG. 7A  is an axial centerline sectional schematic view of another embodiment of an introducer tip the invention. 
           [0025]      FIG. 7B  is an axial centerline sectional schematic view of the tip of  FIG. 7A  showing an extended probe. 
           [0026]      FIG. 7C  is an axial centerline sectional schematic view of the tip of  FIG. 7A  showing an attached pericardium. 
           [0027]      FIG. 7D  is an axial centerline sectional schematic view of the tip of  FIG. 7A  showing a pierced pericardium and deployment of a guidewire. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0028]    Specific details described herein, including what is stated in the Abstract, are in every case a non-limiting description and exemplification of embodiments representing concrete ways in which the concepts of the invention may be practiced. This serves to teach one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure or manner consistent with those concepts. Any examples or illustrations given herein are not to be regarded in any way as restrictions on, limits to, or express definitions of, any term or terms with which they are utilized. Instead, these examples or illustrations are to be regarded as being described with respect to one particular embodiment and as illustrative only. Those of ordinary skill in the art will appreciate that any term or terms with which these examples or illustrations are utilized will encompass other embodiments that may or may not be given therewith or elsewhere in the specification and all such embodiments are intended to be included within the scope of that term or terms. Language designating such non-limiting examples and illustrations includes, but is not limited to: “for example,” “for instance,” “e.g.,” “in an embodiment,” “in an exemplary embodiment.” 
         [0029]    Reference throughout this specification to “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one exemplary embodiment of the present invention. Thus, the appearances of the phrase “in an exemplary embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. It will be seen that various changes and alternatives to the specific described embodiments and the details of those embodiments may be made within the scope of the invention. It will be appreciated that one or more of the elements depicted in the drawings can also be implemented in a more separated or integrated manner, or even removed or rendered as inoperable in certain cases, as is useful in accordance with a particular application. Because many varying and different embodiments may be made within the scope of the inventive concepts herein described and in the exemplary embodiments herein detailed, it is to be understood that the details herein are to be interpreted as illustrative and not as limiting the invention to that which is illustrated and described herein. 
         [0030]    As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such process, article, or apparatus. Further, unless expressly stated to the contrary, “or” refers to an inclusive or and not to an exclusive or. That is, unless otherwise indicated, the term “or” is generally intended to mean “and/or”. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present). 
         [0031]    As used herein, a term preceded by “a” or “an” (and “the” when antecedent basis is “a” or “an”) includes both singular and plural of such term (unless in context the reference “a” or “an” clearly indicates only the singular or only the plural). Thus the use of the word “a” or “an” may mean “one,” but it is also consistent with the meaning of “at least one” and “one or more than one.” 
         [0032]    As used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise. 
         [0033]    In addition, as used herein, the phrase “connected” means joined to or placed into communication with, either directly or through intermediate components. 
         [0034]    The various directions such as “upper,” “top”, “lower,” “bottom”, “back,” “front,” “transverse,” “vertical”, “horizontal,” “length,” “Longitudinal,” “width,” “laterally,” “forward,” “rearward” and so forth used in the detailed description of exemplary embodiments are made only for easier explanation in conjunction with the drawings. The components may be oriented differently while performing the same function and accomplishing the same result as the exemplary embodiments herein detailed embody the concepts of the invention, and such terminologies are not to be understood as limiting the concepts which the embodiments exemplify. 
         [0035]    The current invention,  100  is a next generation device of the prior art device described in U.S. Pat. Nos. 5,827,216; 5,900,433; 6,162,195 and 6,666,844, the contents of which are incorporated in their entirety. Several improvements over the prior art device is shown in  FIG. 1 . Notably there is a finger grip  102  on the edge by the vacuum connection. This orients the hand more intuitively. There are push tabs  104  on the sides of the device which also orient the hands. The needle is locked within the housing to prevent premature advancement which will inhibit piercing of the pericardium. A locking release button  106  on the side of the unit will permit unlocking and advancement of the needle when ready by the user. The proximal end of the device is a female leur device  108  instead of the integral Tuohy found on the prior art device. This still permits a Tuohy to be attached and a stopcock so that fluids can be injected into the device through the needle, as desired. A principal change is changing the standard beveled needle which used to require rotation, to a Tuohy which does not require rotation to pierce the pericardium and keep the needle tip low in profile and near the same plane as the bottom of the needle shaft. This permits optimum piercing of the pericardium, as explained later. 
         [0036]    The invention  100  also has changes in the tip  120  and the bleb chamber  122 , as shown in  FIG. 2A . As vacuum is applied, the pericardium is drawn up into the bleb chamber  122 . To ensure that the pericardium is completely drawn into the bleb chamber, small channels are molded into the tip (vacuum fingers  124 ) so that with a partially drawn-in pericardium in the proximal part of the bleb chamber, there still is vacuum to the distal end of the bleb chamber to ensure that the pericardium is fully drawn into the bleb chamber. An end view of the vacuum fingers or grooves is seen in  FIG. 2B .  FIG. 2B  also shows a lower portion of tip  120  provided with reliefs  133  in the tip to effect a serration to help scrub pericardial fat from the surface of the pericardium. Also, as shown in  FIG. 2B , a flexible area  135  is provided around the tip so that the distal portion of the tip can flexibly adapt to the pericardial/heart geometry without being rigid. 
         [0037]    While the current bleb chamber  122  of the present invention and the prior art device are hemispherical, there is no reason that they need to be. An obround chamber is fully possible, shown in  FIG. 2 . As “X”  126  goes to zero, then the chamber becomes a hemisphere if R 1  ( 128 )=R 2  ( 130 ). The vacuum fingers  124  become increasingly important as X ( 126 )&gt;0 due to the direction of the vacuum pressure. 
         [0038]    A goal of the present invention is to safely puncture the pericardial sac and be in fluid communication with the heart to deliver therapies. Currently, the bottom of the plastic tip of the device is parallel to the axis of the needle. As long as the tip of the needle  134  does not protrude outside a line between the proximal and distal part of the bleb chamber, then the heart cannot be lacerated. Consequently, the angle β ( 132 ) can be confirmed, as shown in  FIGS. 2A and 3 . Then β represents the angle from the edge of the distal portion of the bleb chamber to the distal tip of the needle and to the proximal edge of the bleb chamber so the needle cannot touch the heart. 
         [0039]    The Tuohy needle  134  is an advantage over the previous straight beveled needle, as the tip of the Tuohy is bent so that the tip is on a plane with the lower part of the needle tubing. Obviously the exit of the needle needs to be pointed down (towards the heart) for maximum benefit for addition of fluid, removal of fluid, and for placing a guidewire  136 , which is resident within the needle  134 , as shown in  FIG. 3 . Using a conventionally beveled needle as in the prior art device, the needle was rotated so that the bevel was in the “up” position (away from the heart) to pierce the pericardium and then rotated so that the bevel was “down” (toward the heart) for fluid aspiration/delivery and for guidewire delivery. The Tuohy removes the need for needle rotation and therefore makes the device simpler to operate. 
         [0040]    The prior art device had a solid tip and “bleb” chamber for the vacuum introduction of the pericardium into the instrument. The size of the tip  120  determined the size of the incision into the patient and the diameter of the dilator/sheath. In this circumstance, the smaller the incision/introducer, the better it is for the patient. However, a thickened pericardium, the choice of larger needle sizes for lancing the pericardium, and entering the pericardium for heart access would argue for larger tips  120 . This embodiment permits both, by permitting smaller incisions and instrument introduction while deployable and expansive tip.  FIG. 4  (A-D) illustrates the tip of this embodiment device, generally noted as  200 .  FIG. 4A  illustrates the device as introduced into the patient.  FIG. 4B  illustrates the apparatus  200  extended.  FIG. 4C  illustrates the end view of the apparatus  200 .  FIG. 4D  illustrates the bottom view of the apparatus  200  with the needle  214  deployed. 
         [0041]    Notable is the nose of the device  210 , which has a variety of struts  220  attached thereto. The struts  220  are preferably made of Nitenol, a memory metal but can be made of any material which can hold its shape. The needle  214  is housed in a tube  216  and the apparatus is housed in a sheath  218 . The deployed struts  220  expand to form a canopy, as illustrated in  FIG. 4B . Flexible housing  230  is sealed to the inside of the rigid sheath  218  and is formed into shape by struts  220 , once deployed.  FIG. 4C  illustrates an end view of the device showing the formation of flexible housing  230 . After vacuum is applied within sheath  218 , the pericardium will be pulled into the flexible housing  230 , braced by struts  220 .  FIG. 4D  illustrates the underside of the device and has a circular opening  232 . When vacuum is deployed within sheath  218 , the circular opening will seal against the pericardium and permit a pericardial bleb to be drawn into the geometry formed by struts  220  and flexible housing  230 . At that point, the needle  214  is advanced and pierces the pericardium. Once pierced, the interior of the needle  214  is in communication with the inside of the pericardium and therefore the exterior of the heart. Fluid from the pericardial space can be withdrawn, fluid can be added through the needle into the pericardial space, and/or a guidewire can be deployed via the needle into the pericardial space. At the appropriate time, the needle  214  may be pulled back into the tube  216 , and the struts pulled back into the sheath  218  and the device again resembling the configuration of  FIG. 4A . In this low profile configuration, the device can be removed from the patient. 
         [0042]      FIG. 5A  illustrates another embodiment of the present invention. The distal tip of the device is generally shown as  300 , with the housing shown as  302  and the bleb chamber  304 . It is always worthwhile to have positive feedback that the pericardium has indeed been captured into the bleb chamber  304  so that the needle  306  may advance into the bleb chamber  304 , pierce the captured pericardium, and be in fluid communication with the outside of the heart. To help effect this feedback, a miniature CCD camera  310  is placed in the tip  300 . Window  308  may be suitable as a filter or other optical mechanism to assist the camera  310  in transmitting the image within the bleb chamber  304  to the physician or other individual outside the patient. This can provide confirmation that the pericardium has indeed been captured into the bleb chamber  304  and it is appropriate to advance the needle  306  to pierce the pericardium captured within the bleb chamber  304  using vacuum. 
         [0043]    The filter  308  and the camera  310  may be coupled with an electronics system outside the device, as illustrated in  FIG. 5B . The device is shown generally as  320 . Wires (or wireless communications), shown as  322  and  324 , electronically connect the device  320  to the outside electronics, generally shown as  326 . The optical camera/detector  310  aided by software and/or the physical window/filter  308  detects the presence of the pericardial sac being pulled into the bleb chamber  304  by applied vacuum. The optical characteristics of that event will cause a change in the output of the camera/detector  310  and this signal change can be processed by the electronics  326  in a very straightforward threshholding manner. This will change indicator lights from “W” (wait to advance the needle) to “P” (advance to puncture the pericardium) as the system will have determined, after the application of vacuum, if the pericardium has been captured into the bleb chamber  304 . In this manner, the operators of the device have the operational feedback they need to more accurately. Both of these approaches are represented in  FIGS. 5A and 5B . 
         [0044]      FIG. 6  illustrates another embodiment of the present invention and is about control over the tip. The general device is illustrated as  400 . The proximal end contains control paddles  402 ,  404 ,  406  and  408 , as shown in  FIG. 6A . Paddles  402  and  404  are connected together as are paddles  406  and  408 , so when paddle  402  is depressed inward, paddle  404  extends outward and vice versa. The same is true for paddles  406  and  408 , so when paddle  408  is depressed inward, paddle  406  moves outward and vice versa.  FIG. 6B  illustrates that control cables  410  are connected to each of the paddles and to the respective portion of the tip  412 , shown in two of four places  414 —two to produce vertical movement with the paddles and two to produce lateral movement with the paddles. The shaft of the device includes the rigid portion  416  and a flexible portion  418 . In use, moving paddle  402  inward, as shown in  FIG. 6B  causes the control wire  410  attached to the paddle  402  to tighten, and the control wire  410  attached to the other paddle  404  to have slack. The resultant motion moves the tip upward, as shown.  FIG. 6C  illustrates the reverse function and moving paddle  404  inward causes paddle  402  to move outward and causes the tip  412  to move downward. Analogously, moving paddles  406  and  408  inward/outward causes the tip  412  to move laterally. These paddle pairs work independently so that the tip  412  may by gyrated into a combination of vertical and lateral positions as desired by the operator and using said paddles. 
         [0045]    Another embodiment uses the concept of a tunneling rod. This is a Tuohy needle which may eliminate the need for a sheath/dilator. In this embodiment shown in  FIG. 7  (A-D), the distal portion of the tip is shown generally as  700  in  FIG. 7A , with an overmolded septum  704  and vacuum fingers  703 . The lower portion of tip  709  also has a lateral geometry like a serration to help scrub pericardial fat from the surface of the pericardium. After the incision in the body is made, the Tuohy needle  708  is extended through the septum  704 , as illustrated in  FIG. 7B . The needle and the slender shape of tip  702  may make the insertion easier and may reduce or eliminate the need for a sheath/dilator. Once in place, the needle is retracted, as shown in  FIG. 7C . The septum  704  reseals the tip  700 . Vacuum is applied and the pericardium  710  is drawn into the bleb chamber  706 .  FIG. 7D  illustrates the needle  708  is advanced into the bleb chamber  706  and it pierces the pericardium  710 . The needle can add and/or remove material and/or places an internal guidewire  714  as shown, to give therapy to the heart  716 . 
         [0046]    Overmolding can also provide other advantages, such as an extended sealing area around the lower edge of the bleb chamber for more efficient pericardial access and capture. It can also provide a flexible area around the tip so that the distal portion of the tip can flexibly adapt to the pericardial/heart geometry without being rigid. 
         [0047]    It can be seen that most to all of these embodiments can be combined into a pericardial access device providing a variety of advantages and features. 
         [0048]    The above disclosed subject matter is to be considered illustrative, and not restrictive, and the appended claims are intended to cover all modifications, enhancements, and other embodiments that fall within the true scope of the present invention, which to the maximum extent allowed by law, is to be determined by the broadest permissible interpretation of the following claims and their equivalents, unrestricted or limited by the foregoing detailed descriptions of exemplary embodiments of the invention.