Abstract:
Devices and methods for increasing the volume of blood pumped by a heart muscle are disclosed. A therapeutic catheter in accordance with the present invention may comprise an elongate shaft having a proximal end, a distal end, and a lumen extending through at least a portion thereof. The therapeutic catheter may further include a cutter having a cutter lumen fixed to the distal end of the elongate shaft, and a mooring shaft slidingly disposed within the lumen of the elongate shaft. A method in accordance with the present invention may include the steps of engaging a muscle of a donor site with a portion of the mooring shaft, penetrating the muscle of the donor site with the cutter to form a muscle tendril, withdrawing the muscle tendril from the muscle of the donee site, positioning the distal end of the therapeutic catheter proximate a pit defined by the tissue of a donee site, inserting the muscle tendril into the tissue of the donee site, and disengaging the mooring shaft from the muscle tendril.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to devices and methods for increasing the blood pumping efficiency of a heart muscle. More particularly, the present invention relates to devices and methods for treating a heart including one or more areas of non-contracting myocardial tissue that are causing low output ejection fraction. 
     BACKGROUND OF THE INVENTION 
     The blood pumping action of the heart muscle is critical to sustaining the life of a patient. One condition that is likely to reduce the blood pumping efficiency of the heart muscle is ventricular dilation. When ventricular dilation occurs a ventricle chamber (commonly the left ventricular chamber) becomes enlarged. As the chamber becomes enlarged, the internal surface area of the chamber increases rapidly. Blood flowing within the heart applies pressure to the internal surface of the heart chamber. Because the blood applies pressure inside the heart chamber across an increased surface area, the force which must be produced by the heart in order to pump blood also increases. In many cases, the cardiac disease which caused the ventricular dilation also limits the ability of the heart muscle to produce the increased force required to efficiently pump blood. In many cases, the dilation of the heart chamber becomes progressively worse, and the blood pumping efficiency of the heart muscle progressively declines. Ultimately, ventricular dilation may result in heart failure. 
     In order for the heart to function properly the tissues of the heart muscle must be continuously supplied and re-supplied with oxygen. To receive an adequate supply of oxygen, the heart muscle must be well perfused with blood. If the flow of blood to a portion of the heart muscle is interrupted or diminished, that portion of the heart muscle may stop contributing to the blood pumping action of the heart muscle. 
     In a healthy heart, blood perfusion is accomplished with a system of blood vessels and capillaries. However, it is common for the blood vessels to become occluded (blocked) or stenotic (narrowed). A stenosis may be formed by an atheroma that is typically a harder, calcified substance that forms on the walls of a blood vessel. 
     Historically, individual stenotic lesions have been treated with a number of medical procedures including coronary bypass surgery, angioplasty, and atherectomy. Coronary bypass surgery typically involves utilizing vascular tissue from another part of the patient&#39;s body to construct a shunt around the obstructed vessel. Angioplasty techniques such as percutaneous transluminal angioplasty (PTA) and percutaneous transluminal coronary angioplasty (PTCA) are relatively non-invasive methods of treating a stenotic lesion. These angioplasty techniques typically involve the use of a guidewire and a balloon catheter. In these procedures, a balloon catheter is advanced over a guidewire such that the balloon is positioned proximate a restriction in a diseased vessel. The balloon is then inflated and the restriction in the vessel is opened. A third technique that may be used to treat a stenotic lesion is atherectomy. During an atherectomy procedure, the stenotic lesion is mechanically cut or abraded away from the blood vessel wall. 
     Coronary by-pass, angioplasty, and atherectomy procedures have all been found effective in treating individual stenotic lesions in relatively large blood vessels. However, the heart muscle is perfused with blood through a network of small vessels and capillaries. In some cases, a large number of stenotic lesions may occur in a large number of locations throughout this network of small blood vessels and capillaries. The torturous path and small diameter of these blood vessels limit access to the stenotic lesions. The sheer number and small size of these stenotic lesions make techniques such as cardiovascular by-pass surgery, angioplasty, and atherectomy impractical. 
     When techniques that treat individual lesions are not practical other techniques of improving the oxygenation of myocardial tissue may be utilized. One technique of improving the oxygenation of myocardial tissue is known as percutaneous myocardial revascularization (PMR). A PMR procedure generally involves the creation of holes, craters or channels directly into the myocardium of the heart. PMR was inspired in part by observations that reptilian heart muscles are supplied with oxygen primarily by blood perfusing directly from within heart chambers to the heart muscle. This contrasts with the human heart, which is supplied by coronary vessels receiving blood from the aorta. Positive clinical results have been demonstrated in human patients receiving PMR treatments. These results are believed to be caused in part by blood flowing within a heart chamber through channels in myocardial tissue formed by PMR. Increased blood flow to the myocardium is also believed to be caused in part by the healing response to wound formation. Specifically, the formation of new blood vessels is believed to occur in response to the newly created wound. This response is sometimes referred to as angiogenisis. In addition to promoting increased blood flow, it is also believed that PMR improves a patient&#39;s condition through denervation. Denervation is the elimination of nerves. The creation of wounds during a PMR procedure results in the elimination of nerve endings which were previously sending pain signals to the brain as a result of hibernating tissue. 
     SUMMARY OF THE INVENTION 
     The present invention relates generally to devices and methods for increasing the volume of blood pumped by a heart muscle. More particularly, the present invention relates to devices and methods for treating a heart including one or more areas of non-contracting myocardial tissue that are causing low output ejection fraction. A therapeutic catheter in accordance with the present invention includes a distal end, a proximal end, and an elongate shaft defining a lumen. A hub is disposed about the elongate shaft proximate its proximal end and a cutter is fixed to the elongate shaft proximate its distal end. The cutter includes a distal edge and a cutter lumen. 
     The therapeutic catheter also includes a mooring member disposed at a distal end of a mooring shaft. In a preferred embodiment, the mooring shaft is slidingly disposed within the lumen of the elongate shaft and cutter lumen of the cutter. A knob is fixed to a proximal end of the mooring shaft. In a preferred embodiment, the knob is adapted to be rotated by the fingers of a physician. In this preferred embodiment, the rotary motion of the knob is transferred to the mooring member via the mooring shaft. 
     A trocar in accordance with the present invention includes a body defining a trocar lumen. The body of the trocar includes a flange, a penetrating portion, a distal end, and a proximal end. A proximal aperture of the trocar is in fluid communication with the trocar lumen. In a preferred embodiment, the trocar lumen of the trocar is adapted to receive the therapeutic catheter. In a preferred method in accordance with the present invention, the distal end of the therapeutic catheter is inserted into the trocar lumen through the proximal aperture. 
     A guide catheter in accordance with the present invention includes an elongate tubular member defining a central lumen. A plurality of moorings are disposed proximate a distal end of the guide catheter. In one method in accordance with the present invention, the moorings may be utilized to retain the distal end of the guide catheter proximate a donee site. In a preferred embodiment, each mooring comprises a vacuum orifice. In this preferred embodiment, each vacuum orifice is in fluid communication with a vacuum lumen defined by the elongate tubular member of the guide catheter. 
     Other embodiments of the moorings are possible without deviating from the spirit or scope of the present invention. For example, each mooring may be comprised of an elongate wire with a helix disposed proximate its distal end. The helical end of the elongate wire may be “threaded” into the tissue proximate the donee site by rotating the wire. Additional examples, of moorings that may be appropriate in some applications include hooks and barbs. 
     A method in accordance with the present invention may include the step of penetrating the skin of a patient with a trocar near a donor site. In a preferred method, the donor site includes muscle tissue. Examples of donor sites that may be suitable in some applications include arms and legs. 
     The distal end of a therapeutic catheter in accordance with the present invention may be inserted through a proximal orifice of the trocar. The therapeutic catheter may be urged forward through a lumen of the therapeutic catheter until a cutter of the therapeutic catheter contacts muscle tissue proximate the donor site. The mooring shaft may be urged forward within the lumen of the therapeutic catheter by applying a pushing force to the knob disposed at the proximal end of the mooring shaft. The mooring shaft may be urged forward until the mooring member of the therapeutic catheter contacts the muscle tissue of the donor site. The mooring member of the therapeutic catheter may be coupled to the muscle tissue of the donor site. In a preferred method, the mooring member is fixed to the muscle tissue by threading it into the tissue. In this preferred method, the mooring member may be rotated by applying a rotational force to the knob fixed to the proximal end of the mooring shaft. 
     A tendril of muscle tissue may be cut from the donor site. In a preferred method, the step of cutting the muscle tendril includes the step of urging a cutter into the muscle tissue of the donor site. The therapeutic catheter may be withdrawn from the donor site with the tendril of muscle tissue disposed within the cutter lumen. 
     Methods in accordance with the present invention have been envisioned in which a pulling force is applied to the knob disposed at the end of the mooring shaft. The step of pulling on the mooring shaft may be utilized to urge the muscle tendril proximally. Methods in accordance with the present invention have been envisioned in which one or more muscle tendrils are pulled into the lumen of the therapeutic catheter. 
     A guide catheter may be introduced into the vasculature of the patient. The guide catheter is urged forward until its distal tip is proximate a desired donee site. In a preferred method, the distal tip is urged forward until it is disposed within the heart of the patient. 
     Once the distal end of the sheath is positioned proximate a desire donee site, the guide catheter may be advanced so that its distal end contacts the tissue proximate the donee site. The moorings of the guide catheter may then be activated to stabilize the distal end of the guide catheter. In one embodiment of the present invention, each mooring comprises of a vacuum orifice in fluid communication with a vacuum lumen. In one method in accordance with the present invention, the moorings of the guide catheter are activated by applying vacuum from a vacuum source to the vacuum orifices via the vacuum lumens. 
     A pit or channel may be created in the tissue of the donee site proximate the distal end of the guide catheter. A number of methods are known in the art for creating channels or pits in body tissue. Examples of methods that may be suitable in some applications include mechanical cutting and burning by exposure to electromagnetic energy. Examples of types of electromagnetic energy that may be suitable in some applications include radio frequency energy and LASER light. A pit forming catheter may be utilized to remove material proximate the distal end of the guide catheter. A process in accordance with the present invention may include the step of inserting a pit forming catheter into the lumen of the guide catheter. The pit forming catheter may be urged forward until its distal end is proximate the distal end of the guide catheter. A pit forming member disposed proximate the distal end of the pit forming catheter may be utilized to form a pit in the tissue proximate the donee site. Examples of pit forming members that may be suitable in some applications include knives, tomes, optical fibers, and electrodes. The pit forming catheter may be withdrawn from the lumen of the guide catheter. 
     The distal end of a therapeutic catheter may be inserted into the proximal port of the guide catheter. The therapeutic catheter may be urged forward within the lumen of the guide catheter until the distal portion of the therapeutic catheter is disposed proximate the pit or channel in the tissue of the donee site. The muscle tendril may then be urged into the pit or channel in the tissue of the donee site. In a preferred method, the muscle tendril is urged forward by applying a pushing force on the knob fixed to the proximal end of the mooring shaft. 
     While the muscle tendril is disposed within the pit or channel in the tissue of the donee site, the muscle tendril may be, preferably, fixed in place with an anchor member. Various anchor members may be utilized without deviating from the spirit and scope of the present invention. Examples of anchor members include sutures, staples, cauterized areas of tissue, adhesive bonds, cork screws, wire loops, sleeves, barbs, and hooks. After the muscle tendril has been positioned in the pit or channel and preferably, anchored, the mooring member of the therapeutic catheter may be disengaged from the muscle tendril. In a preferred method, the mooring is disengaged from the muscle tendril by applying a rotational force to the knob fixed to the proximal end of the mooring shaft. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view including a therapeutic catheter and a trocar in accordance with the present invention; 
     FIG. 2 is a cross-sectional view of a trocar utilized to access a muscle within a donor site in a method in accordance with the present invention; 
     FIG. 3 is a perspective view of the distal portion of a guide catheter in accordance with the present invention; 
     FIG. 4 is a plan view of a patient and a therapeutic catheter system in accordance with the present invention; 
     FIG. 5 is a plan view of an anchor member in accordance with an exemplary embodiment of the present invention; 
     FIG. 6 is a cross-sectional view of the anchor member of FIG. 5; 
     FIG. 7 is a partial cross sectional view of the catheter of FIG. 1; 
     FIG. 8 is a partial cross sectional view of a distal portion of the catheter in FIG. 7; 
     FIG. 9 is a cross sectional view of a heart and a muscle tendril disposed within a heart wall of the heart; 
     FIG. 10 is a partial cross section view of a catheter in accordance with an exemplary embodiment of the present invention; 
     FIG. 11 is a plan view of a muscle tendril having a first end portion disposed within a first lumen of a first anchor and a second end portion disposed within a second lumen of a second anchor; 
     FIG. 12 is a plan view of muscle tendril that is disposed within a heart which is shown in cross section; 
     FIG. 13 is a plan view of an additional embodiment of an anchor in accordance with an exemplary embodiment of the present invention; 
     FIG. 14 is a cross sectional view of a heart wall including a localized area of non-contracting tissue  652 ; and 
     FIG. 15 is a partial cross sectional view of a heart and a muscle tendril spanning the chamber of a left ventricle of the heart. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following detailed description should be read with reference to the drawings, in which like elements in different drawings are numbered identically. The drawings which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of the invention. Examples of constructions, materials, dimensions, and manufacturing processes are provided for various elements. Those skilled in the art will recognize that many of the examples provided have suitable alternatives which may be utilized. 
     FIG. 1 is a perspective view of a therapeutic catheter  120  in accordance with the present invention. In the embodiment of FIG. 1, therapeutic catheter  120  includes a distal end  124 , a proximal end  122 , and an elongate shaft  126  defining a lumen  130 . A hub  128  is disposed about elongate shaft  126  proximate a proximal end  132  thereof. A cutter  136  is fixed to elongate shaft  126  proximate a distal end  134  thereof. Cutter  136  includes a distal edge  138  and a cutter lumen  140 . 
     Therapeutic catheter  120  also includes a mooring member  146  disposed at a distal end of  144  of a mooring shaft  150 . In the embodiment of FIG. 1, mooring member  146  includes a helix  148 . Mooring shaft  150  is slidingly disposed within lumen  130  of elongate shaft  126  and cutter lumen  140  of cutter  136 . A knob  160  is fixed to a proximal end  122  of mooring shaft  150 . In a preferred embodiment, knob  160  is adapted to be rotated by the fingers of a physician. In this preferred embodiment, the rotary motion of knob  160  is transferred to mooring member  146  via mooring shaft  150 . 
     In a preferred embodiment, mooring member  146  and mooring shaft  150  are comprised of a metallic wire. Metals that may be suitable in some applications include stainless steel and nickel titanium alloy. It is to be appreciated that other metallic and non-metallic materials may be utilized without deviating from the spirit and scope of the present invention. 
     It will also be appreciated that elongate shaft  126  may be comprised of many materials without deviating from the spirit and scope of the present invention. In a preferred embodiment, elongate shaft  126  is comprised of polyether block amide (PEBA). Polyether block amide is commercially available from Atochem Polymers of Birdsboro, Pennsylvania under the trade name PEBAX. Also in a preferred embodiment, elongate shaft  126  is fabricated using an extrusion process. 
     It is to be understood that other manufacturing processes can be used without departing from the spirit and scope of the present invention. Elongate shaft  126  may also be comprised of other materials without departing from the spirit of scope of this invention. Examples of materials that may be suitable in some applications include: polyethylene (PE), polypropylene (PP), polyvinylchloride (PVC), polyurethane, and polytetrafluoroethylene (PTFE). Elongate shaft  126  may also include a reinforcement member. Examples of reinforcement members that may be suitable in some applications include a plurality of strands disposed in a braided pattern, a plurality of fibers knitted together, and a coiled wire. 
     Therapeutic catheter  120  may include one or more radiopaque markers. One example of a radiopaque marker is a band of radiopaque material disposed proximate the distal end of therapeutic catheter  120 . Radiopaque bands of this type aid the physician in determining the location of the distal end of the device relative to the patient&#39;s anatomy. The radiopaque band may be comprised of a number of materials. Examples of materials that may be suitable in some applications include gold, platinum, tungsten, iron, silver, and thermoplastic material loaded with a radiopaque filler. Examples of radiopaque filler that may be suitable in some applications include barium sulfate, bismuth subcarbonate, bismuth trioxide, bismuth oxychloride, bismuth subcarbonate, tungsten powder, and depleted uranium. 
     Cutter  136  of therapeutic catheter  120  may be comprised of a variety of metallic and non-metallic materials. Examples of metallic materials that may be suitable in some applications include stainless steel, and nickel-titainium alloy. Examples of non-metallic materials that may be suitable in some applications include polycarbonate, polyacrylate, polyimide, and polyamide. Cutter  136  may be fixed to elongate shaft  126  using any suitable method. Examples of methods that may be suitable in some applications include welding, adhesive bonding, and mechanical coupling. 
     FIG. 2 is a cross-sectional view of a trocar  256  disposed proximate a donor site  270 . Trocar  256  includes a body  258  defining a trocar lumen  262 . Body  258  includes a flange  264 , a penetrating portion  266 , a distal end  254 , and a proximal end  252 . In FIG. 2, penetrating portion  266  of body  258  of trocar  256  has penetrated a skin  268  of a human body proximate donor site  270 . As shown in FIG. 2, a distal end  254  of trocar  256  is disposed proximate a muscle  272  of donor site  270 . A proximal aperture  274  of trocar  256  is in fluid communication with trocar lumen  262 . In a preferred embodiment, trocar lumen  262  of trocar  256  is adapted to receive therapeutic catheter  120 . In a preferred method in accordance with the present invention, distal end  124  of therapeutic catheter  120  is inserted into trocar lumen  262  through proximal aperture  274 . 
     FIG. 3 is a perspective view of a distal portion  156  of a guide catheter  158  in accordance with the present invention. Guide catheter  158  includes an elongate tubular member  166  defining a central lumen  152 . A plurality of moorings  168  are disposed proximate a distal end  164  of guide catheter  158 . In one method in accordance with the present invention, moorings  168  may be utilized to retain distal end  164  of guide catheter  158  proximate a donee site. In the embodiment of FIG. 3, each mooring  168  comprises a vacuum orifice  172 . Each vacuum orifice  172  is in fluid communication with a vacuum lumen  170  defined by elongate tubular member  166 . 
     Other embodiments of moorings  168  are possible without deviating from the spirit or scope of the present invention. For example, each mooring  168  may be comprised of an elongate wire with a helix disposed proximate its distal end. The helical end of the elongate wire may be “threaded” into the tissue proximate the donee site by rotating the wire. Additional examples, of moorings  168  that may be appropriate in some applications include hooks and barbs. 
     Guide catheter  158  may be comprised of many materials without deviating from the spirit and scope of the present invention. In a preferred embodiment, guide catheter  158  is comprised of polyether block amide (PEBA). Polyether block amide is commercially available from Atochem Polymers of Birdsboro, Pennsylvania under the trade name PEBAX. Also in a preferred embodiment, guide catheter  158  is fabricated using an extrusion process. 
     It is to be understood that other manufacturing processes can be used without departing from the spirit and scope of the present invention. Guide catheter  158  may also be comprised of other materials without departing from the spirit of scope of this invention. Examples of materials that may be suitable in some applications include: polyethylene (PE), polypropylene (PP), polyvinylchloride (PVC), polyurethane, and polytetrafluoroethylene (PTFE). Guide catheter  158  may also include a reinforcement member. Examples of reinforcement members that may be suitable in some applications include a plurality of strands disposed in a braided pattern, a plurality of fibers knitted together, and a coiled wire. 
     Guide catheter  158  may include one or more radiopaque markers. One example of a radiopaque marker is a band of radiopaque material disposed proximate the distal end of guide catheter  158 . Radiopaque bands of this type aid the physician in determining the location of the distal end of the device relative to the patient&#39;s anatomy. The radiopaque band may be comprised of a number of materials. Examples of materials that may be suitable in some applications include gold, platinum, tungsten, iron, silver, and thermoplastic material loaded with a radiopaque filler. Examples of radiopaque filler that may be suitable in some applications include barium sulfate, bismuth subcarbonate, bismuth trioxide, bismuth oxychloride, bismuth subcarbonate, tungsten powder, and depleted uranium. 
     FIG. 4 is a plan view of a patient  202  and a therapeutic catheter system  200  including a guide catheter  158  having a central lumen and a plurality of moorings  168  (shown in FIG. 3) disposed proximate the distal end thereof. In the embodiment of FIG. 4, each mooring  168  (shown in FIG. 3) comprises a vacuum orifice  172  (shown in FIG. 3) in fluid communication with a vacuum lumen  170  (shown in FIG. 3) defined by guide catheter  158 . A multi-port adapter  174  is disposed at a proximal end  162  of guide catheter  158 . A vacuum port  176  of multi-port adapter  174  is in fluid communication with vacuum lumens  170  (shown in FIG. 3) of guide catheter  158 . 
     An actuator  178  is coupled to moorings  168  (shown in FIG. 3) of guide catheter  158 . In the embodiment of FIG. 4, actuator  178  includes an actuating lever  180  and a valve body  184 . Valve body  184  is in fluid communication with vacuum orifices  172  (shown in FIG. 3) via vacuum port  176  of multi-port adapter  174  and vacuum lumens  170  (shown in FIG. 3) of guide catheter  158 . Valve body  184  is also in fluid communication with a vacuum source  186 . In the embodiment of FIG. 4, actuator  178  may selectively actuate moorings  168  (shown in FIG. 3) by selectively placing vacuum orifices  172  (shown in FIG. 3) in fluid communication with vacuum source  186 . 
     A therapeutic catheter  120  is slidingly disposed within central lumen  152  (shown in FIG. 3) of guide catheter  158  and passes through a proximal port  188  of multi-port adapter  174 . In the embodiment of FIG. 4, therapeutic catheter  120  includes an elongate shaft  126  defining a lumen  130  (shown in FIG.  1 ). A hub  128  is disposed about elongate shaft  126  proximate a proximal end  132  thereof. A cutter  136  (shown in FIG. 1) is fixed to elongate shaft  126  proximate a distal end  134  (shown in FIG. 1) thereof. 
     A mooring shaft  150  is slidingly disposed within the lumen of elongate shaft  126 . A mooring member is disposed at the distal end of mooring shaft  150 . A knob  160  is fixed to a proximal end  142  of mooring shaft  150 . In a preferred embodiment, knob  160  is adapted to be rotated by the fingers of a physician. In this preferred embodiment, the rotary motion of knob  160  is transferred to the mooring member disposed at the distal end of mooring shaft  150 . 
     An access catheter  204  is positioned such that its distal end is positioned within a blood vessel  206  of a vasculature  208  of patient  202 . Access catheter  204  may aid in the introduction of guide catheter  158  into blood vessel  206 . 
     In FIG. 4, distal end  164  (shown in FIG. 3) of guide catheter  158  is positioned within a heart muscle  182  of patient  202 . Distal end  164  (shown in FIG. 3) of guide catheter  158  is fixed to heart muscle  182  by moorings  168 (shown in FIG.  3 ). 
     Having thus described FIG.  1  through FIG. 4, methods in accordance with the present invention may now be described with reference thereto. It should be understood that steps may be omitted from these processes and/or the order of the steps may be changed without deviating from the spirit or scope of the invention. It is anticipated that in some applications, two or more steps may be performed more or less simultaneously to promote efficiency. 
     A method in accordance with the present invention may include the step of penetrating the skin of a patient with a trocar near a donor site. In a preferred method, the donor site includes muscle tissue. Examples of donor sites that may be suitable in some applications include arms and legs. 
     The distal end of a therapeutic catheter in accordance with the present invention may be inserted through a proximal orifice of the trocar. The therapeutic catheter may be urged forward through a lumen of the therapeutic catheter until a cutter of the therapeutic catheter contacts muscle tissue proximate the donor site. The mooring shaft may be urged forward within the lumen of the therapeutic catheter by applying a pushing force to the knob disposed at the proximal end of the mooring shaft. The mooring shaft may be urged forward until the mooring member of the therapeutic catheter contacts the muscle tissue of the donor site. The mooring member of the therapeutic catheter may be coupled to the muscle tissue of the donor site. In a preferred method, the mooring member is fixed to the muscle tissue by threading it into the tissue. In this preferred method, the mooring member may be rotated by applying a rotational force to the knob fixed to the proximal end of the mooring shaft. 
     A tendril of muscle tissue may be cut from the donor site. In a preferred method, the step of cutting the muscle tendril includes the step of urging a cutter into the muscle tissue of the donor site. The therapeutic catheter may be withdrawn from the donor site with the tendril of muscle tissue disposed within the cutter lumen. 
     Methods in accordance with the present invention have been envisioned in which a pulling force is applied to the knob disposed at the end of the mooring shaft. The step of pulling on the mooring shaft may be utilized to urge the muscle tendril proximally. Methods in accordance with the present invention have been envisioned in which one or more muscle tendrils are pulled into the lumen of the therapeutic catheter. 
     A guide catheter may be introduced into the vasculature of the patient. The guide catheter is urged forward until its distal tip is proximate a desired donee site. In a preferred method, the distal tip is urged forward until it is disposed within the heart of the patient. 
     Once the distal end of the sheath is positioned proximate a desired donee site, the guide catheter may be advanced so that its distal end contacts the tissue proximate the donee site. The moorings of the guide catheter may then be activated to stabilize the distal end of the guide catheter. In one embodiment of the present invention, each mooring comprises of a vacuum orifice in fluid communication with a vacuum lumen. In one method in accordance with the present invention, the moorings of the guide catheter are activated by applying vacuum from a vacuum source to the vacuum orifices via the vacuum lumens. 
     A pit or channel may be created in the tissue of the donee site proximate the distal end of the guide catheter. A number of methods may be utilized to create channels or pits in the tissue. Examples of methods that may be suitable in some applications include mechanical cutting and burning by exposure to electromagnetic energy. Examples of general types of electromagnetic energy that may be suitable in some applications include radio frequency energy and LASER light. A pit forming catheter may be utilized to remove material proximate the distal end of the guide catheter. A process in accordance with the present invention may include the step of inserting a pit forming catheter into the lumen of the guide catheter. The pit forming catheter may be urged forward until its distal end is proximate the distal end of the guide catheter. A pit forming member disposed proximate the distal end of the pit forming catheter may be utilized to form a pit in the tissue proximate the donee site. Examples of pit forming members that may be suitable in some applications include knives, tomes, optical fibers, and electrodes. The pit forming catheter may be withdrawn from the lumen of the guide catheter. 
     The distal end of a therapeutic catheter may be inserted into the proximal port of the guide catheter. The therapeutic catheter may be urged forward within the lumen of the guide catheter until the distal portion of the therapeutic catheter is disposed proximate the pit or channel in the tissue of the donee site. The muscle tendril may then be urged into the pit or channel in the tissue of the donee site. In a preferred method, the muscle tendril is urged forward by applying a pushing force on the knob fixed to the proximal end of the mooring shaft. 
     While the muscle tendril is disposed within the pit or channel in the tissue of the donee site, the muscle tendril may be, preferably, fixed in place with an anchor member. Various anchor members may be utilized without deviating from the spirit and scope of the present invention. Examples of anchor members include sutures, staples, cauterized areas of tissue, adhesive bonds, cork screws, wire loops, sleeves, barbs, and hooks. After the muscle tendril has been positioned in the pit or channel and preferably, anchored, the mooring member of the therapeutic catheter may be disengaged from the muscle tendril. In a preferred method, the mooring is disengaged from the muscle tendril by applying a rotational force to the knob fixed to the proximal end of the mooring shaft. 
     FIG. 5 is a plan view of an anchor member  300  in accordance with the present invention. Anchor member  300  comprises a generally tubular frame  306  defining a lumen  308 . Anchor member  300  also includes a plurality of inwardly direct barbs  302  that are directed into lumen  308 , and a plurality of outwardly direct barbs  304  that are directed away from lumen  308 . 
     FIG. 6 is a cross-sectional view of anchor member  300  of FIG.  5 . In FIG. 6, it may be appreciated that anchor member  300  includes a point  320 . In one method in accordance with the present invention, point  320  of anchor member  300  may be urged into the tissue of a donee site. In a particularly preferred embodiment, point  320  of anchor member  300  may be urged into the tissue of a donee site without the prior step of creating a pit or channel in the tissue. In FIG. 6, inwardly direct barbs  302  can be seen protruding into lumen  308  of anchor member  300 . In a method in accordance with the present invention, an end portion a muscle tendril may be inserted into lumen  308 , and inwardly direct barbs  302  may assist in retaining the end portion of the muscle tendril within lumen  308 . 
     FIG. 7 is a partial cross sectional view of catheter  120  of FIG.  1 . In the embodiment of FIG. 7, a muscle tendril  322  is partially disposed within cutter lumen  140  of cutter  136 . A first end portion  324  of muscle tendril  322  is disposed within lumen  308  of anchor member  300 . FIG. 8 is a partial cross sectional view of a distal portion of catheter  120 . In the embodiment of FIG. 8, muscle tendril  322  and anchor member  300  have been urged into a donee tissue  326 . 
     FIG. 9 is a cross sectional view of a heart  428  and a muscle tendril  422  disposed within a heart wall  430  of heart  428 . Heart wall  430  has an outer surface  432  and an inner surface  434 . In a useful embodiment, muscle tendril  422  is disposed between inner surface  434  and outer surface  432 . In a preferred embodiment, muscle tendril  422  disposed so that the longitudinal axis of muscle tendril  422  is generally concentric with outer surface  432  of heart  428 . In a particularly preferred embodiment, muscle tendril  422  disposed so that the longitudinal axis of muscle tendril  422  is generally concentric with outer surface  432  and inner surface  434  of heart  428 . In FIG. 9 it may be appreciated that muscle tendril  422  has a radius of curvature. In a particularly preferred embodiment, the radius of curvature of muscle tendril  422  is similar to the radius of curvature of heart wall  430 . In a particularly preferred embodiment, the radius of curvature of muscle tendril  422  falls between an inner radius  442  of heart wall  430  and an outer radius  444  of heart wall  430 . 
     FIG. 10 is a partial cross section view of a catheter  446  in accordance with an exemplary embodiment of the present invention. Catheter  446  includes a cutter  436  defining a cutter lumen  440 . Cutter  436  is has a generally curved shape with a radius R. A muscle tendril  422  is partially disposed within cutter lumen  440 . The curved shape of catheter  446  may facilitate insertion of muscle tendril  422  into heart wall  430  of heart  428 , as shown in FIG.  9 . In a particularly preferred embodiment, the radius of curvature of cutter  436  is similar to the radius of curvature of heart wall  430 . In a particularly preferred embodiment, the radius of curvature of catheter  446  falls between inner radius  442  of heart wall  430  and outer radius  444  of heart wall  430 . Although one muscle tendril is shown in FIG. 9, it is to be appreciated that a plurality of muscle tendrils may be, preferably, inserted into heart wall  430  of heart  428 . 
     FIG. 11 is a plan view of a muscle tendril  522  having a first end portion  524 A and a second end portion  524 B. In the embodiment of FIG. 11, first end portion  524 A of muscle tendril  522  is disposed within a first lumen  508 A of a first anchor  550 A and second end portion  524 B of muscle tendril  522  is disposed within a second lumen  508 B of a second anchor  550 B. 
     FIG. 12 is a plan view of muscle tendril  522  of FIG.  11 . In FIG. 12, muscle tendril  522  is disposed within a heart  528  which is shown in cross section. Heart  528  includes a left ventricle  20 , a right ventricle  22 , a left atrium  24 , and a right atrium  26 . In a preferred embodiment, muscle tendril  522  aids the life sustaining blood pumping action of heart  528 . During this blood pumping action, blood from the upper portion of the body flows into right atrium  26  via the superior vena cava  28 . Blood from the lower portion of the body flows into the right atrium  26  via the inferior vena cava  30 . A tricuspid valve  32  is in fluid communication with both the right atrium  26  and the right ventricle  22 . When tricuspid valve  32  opens, it allows blood to flow from right atrium  26  into right ventricle  22 . During each heart beat, tricuspid valve  32  closes and right ventricle  22  contracts, pumping blood through the pulmonary valve  34  into the pulmonary artery  36 . The pulmonary artery carries blood to the lungs of the patient. 
     After becoming oxygenated in the lungs, blood returns to the heart via a plurality of pulmonary veins  38  which are each in fluid communication with the left atrium  24 . A mitrial valve  40  is in fluid communication with both left atrium  24  and left ventricle  20 . Blood returning from the lungs via pulmonary veins  38  may pass through mitrial valve  40  into left ventricle  20 . During each heart beat, mitrial valve  40  closes and left ventricle  20  contracts, pumping blood through an aortic valve  42  and into the aorta  44 . After passing through the aorta  44 , oxygenated blood is distributed throughout the body of the patient. 
     The walls of a diseased heart may include areas of non-contracting tissue that may interfere with the life sustaining blood pumping action of heart  528 . An area of non-contracting tissue may comprise a myocardial infarction, a stenosis, and etc. Areas of non-contracting tissue may be caused by, for example, ischmia, which is a decreased supply of blood to an area of tissue. Non-contracting tissue may also be the result of idiopathic disease, which is a disease which develops without an apparent or known cause. Additionally, an area of non-contracting tissue may comprise an area of necrosis which is localized tissue death. An area of non-contracting tissue may also comprise tissue which is hibernating due to reduced blood flow to the effected tissue. 
     As shown in FIG. 12, heart  528  includes a middle heart wall  46  that is disposed between the left ventricle  20  and the right ventricle  22 . Left ventricle  20  includes a left heart wall  48 , a dorsal heart wall  50 , and a ventral heart wall  52  (not shown). Left ventricle  20  also includes a chamber  54  defined by middle heart wall  46 , left heart wall  48 , dorsal heart wall  50 , and ventral heart wall  52 . Right ventricle  22  includes a right heart wall  56 , a dorsal heart wall  58 , and a ventral heart wall  60  (not shown). Right ventricle  22  also includes a chamber  62  defined by middle heart wall  46 , right heart wall  56 , dorsal heart wall  50 , and ventral heart wall  60 . 
     In the embodiment of FIG. 12, first anchor  550 A and first end portion  524 A of muscle tendril  522  are disposed within left heart wall  48  of left ventricle  20 . In a similar fashion, second anchor  550 B and second end portion  524 B of muscle tendril  522  are disposed within right heart wall  56  of right ventricle  22 . Also in the embodiment of FIG. 12, muscle tendril  522  passes through middle heart wall  46  of heart  528 . In a preferred embodiment, muscle tendril  522  assists heart  528  in pumping blood. In a particularly preferred embodiment, muscle tendril  522  assists heart  528  in pumping blood by contracting when left ventricle  20  and right ventricle  22  of heart  528  contract (i.e., muscle tendril itself contracts). 
     FIG. 13 is a plan view of an additional embodiment of an anchor  654  in accordance with the present invention. A distal end  656  of an elongate member  658  is releasably fixed to anchor  654 . In the embodiment of FIG. 13, the releasable fixing of elongate member  658  to anchor  654  is accomplished utilizing a sacrificial material  660  disposed between distal end  656  of elongate member  658  and anchor  654 . In a preferred embodiment, sacrificial material  660  comprises a material that may be selectively decayed via electrolytic corrosion. For example, when it is desirable to disconnect elongate member  658  from anchor  654 , an electrical current may be passed through sacrificial material  660 . This electrical current may cause sacrificial material  660  to corrode, dissolve, or disintegrate until the bond between elongate member  658  and anchor  654  is broken. 
     FIG. 14 is a cross sectional view of a heart wall  630  of a heart  628  including a localized area of non-contracting tissue  652 . Non-contracting tissue  652  may comprise a myocardial infarction, an ischmia, a stenosis, an area of necrosis, hibernating tissue, etc. An insertion catheter  662  is also illustrated in FIG.  14 . In a method in accordance with the present invention, insertion catheter  662  may be utilized to treat heart wall  630 . In FIG. 14, insertion catheter  662  includes a sheath  664  defining a lumen  666 . A first elongate member  658 A and a second elongate member  658 B are both partially disposed within lumen  666  of sheath  664 . First elongate member  658 A has a distal end that is releasably fixed to a first anchor  654 A. In a similar fashion, second elongate member  658 B has a distal end that is releasably fixed to a second anchor  654 B. As shown in FIG. 14, a first end portion  624 A of a muscle tendril  622  is fixed to first anchor  654 A, and a second end portion  624 B of a muscle tendril  622  is fixed to second anchor  654 B. First anchor  654 A is disposed within heart wall  630  proximate a first side  668  of non-contracting tissue  652 . Second anchor  654 B is disposed within heart wall  630  proximate a second side  670  of non-contracting tissue  652 . In a preferred embodiment, muscle tendril  622  assists heart  628  in pumping blood. In a particularly preferred embodiment, muscle tendril  622  assists heart  628  in pumping blood by contracting when heart wall  630  contracts. 
     FIG. 15 is a partial cross sectional view of a heart  628 . In the embodiment of FIG. 15, a distal portion of insertion catheter  662  has been advanced through an aorta  44  and a mitrial valve  40  of heart  628 . A muscle tendril  622  is disposed within a left ventricle  20  of heart  628 . A first end portion  672  of muscle tendril  622  is fixed to a first heart wall  630 A and a second end portion  674  of muscle tendril  622  is fixed to a second heart wall  630 B. 
     In the embodiment of FIG. 15, muscle tendril  622  is disposed so that it spans a chamber of left ventricle  20 . Embodiments of the present invention have been envisioned in which muscle tendrils span other chambers of the heart. Examples of heart chambers include the left atrium chamber, the right atrium chamber, and the right ventricle chamber. Muscle tendrils disposed in this manner may aid the blood pumping action of the heart chambers. Embodiments of the present invention have also been envisioned in which a plurality of muscle tendrils span one or more chambers of the heart. 
     The aforementioned embodiments of the present inventions describe muscle fibril implantations which may be caused to contract by developing electrical connections to adjacent conducting myocytes. It is also contemplated that an external electrical stimulator could be utilized to synchronously excite the muscle fibrils in a manner as to maximize the beating efficiency of the heart. A series of electrically excitable anchors is envisioned that could be connected to a muscle stimulator, similar to those devices used in cardiac myoplasty procedures. 
     Having thus described the preferred embodiments of the present invention, those of skill in the art will readily appreciate that yet other embodiments may be made and used within the scope of the claims hereto attached. Numerous advantages of the invention covered by this document have been set forth in the foregoing description. It will be understood, however, that this disclosure is, in many respects, only illustrative. Changes may be made in details, particularly in matters of shape, size, and arrangement of parts without exceeding the scope of the invention. The invention&#39;s scope is, of course, defined in the language in which the appended claims are expressed.