Patent Publication Number: US-10328190-B2

Title: Implantation of a transapical ventricular assist device and kit for same

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a divisional of U.S. patent application Ser. No. 14/799,703 (now U.S. Pat. No. 9,656,011), filed Jul. 15, 2015, entitled IMPLANTATION OF A TRANSAPICAL VENTRICULAR ASSIST DEVICE AND KIT FOR SAME, and claims priority to U.S. Provisional Application Ser. No. 62/025,119, filed Jul. 16, 2014, the entirety of which is incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a blood pump, and, more particularly, relates to a system and method for facilitating implantation of a blood pump. 
     BACKGROUND 
     In certain disease states, the heart lacks sufficient pumping capacity to meet the needs of the body. This inadequacy can be alleviated by providing a mechanical pumping device referred to as a ventricular assist device (“VAD”) to supplement the pumping action of the heart. Considerable effort has been devoted to providing a VAD which can be implanted and which can remain in operation for months or years to keep the patient alive while the heart heals (bridge-to-recovery), or which can remain in operation permanently (destination therapy) or until a suitable donor heart becomes available if the heart does not heal (bridge-to-transplantation). 
     The VAD is typically connected to the heart, most commonly to the left ventricle, which is responsible for pumping oxygenated blood through the aortic valve to the general body. For example, a VAD may include a pump which is installed in the body outside of the heart. The VAD may have an inlet cannula connected to the interior of the left ventricle and connected to the intake of the pump. The VAD may also include an outlet tube connected to the outlet of the pump, routed along the outside of the heart, and grafted to the aorta. Installation of a VAD, particularly a VAD that makes use of an outflow graft, often requires cardioplegia and/or a cardiopulmonary bypass (“CPB”). Cardioplegia and CPB can extend the time of the implantation procedure and has risks which can be significant. 
     As disclosed in commonly owned U.S. Publication No. 2009/0203957, the disclosure of which is hereby incorporated by reference herein, one solution developed to avoid the need for an outflow graft is a pump that is implantable within the left ventricle, which can pump blood disposed within the left ventricle directly through the aortic valve via an outflow cannula coupled to an outlet of the pump. Installation of such a device is typically performed by inserting the outflow cannula and pump through a cored opening in the apex of the heart. This device avoids the need for connecting an outflow cannula external to the heart, and greatly simplifies the installation procedure. 
     Despite the considerable efforts devoted to improvements in VADs, still further improvement would be desirable. 
     SUMMARY 
     Described herein are systems/kits, methods, and devices that facilitate implantation of a VAD within one or more chambers of the heart. In particular, one aspect of the present disclosure describes a transapical VAD that includes an axial flow pump and a pedestal. Also described is a catheter utilized in conjunction with the implantation of the VAD. The catheter desirably includes at least two lumens one of which operates a balloon and the other of which communicates with a distal end of the catheter and is capable of removing air or other fluid disposed beyond or distal to the balloon. The catheter can also include a transducer, such as a pressure transducer, capable of measuring pressure of a fluid beyond or distal to the balloon. 
     Also described are methods of implantation, which generally include gaining access to the apex of the heart, attaching a mounting ring to the apex, coring the apex through the mounting ring, partially inserting the VAD into the heart through the cored opening, de-airing the VAD via a catheter, continuing advancement of the VAD into the heart, measuring a physical condition within the heart, such as pressure, affixing the VAD to the heart, removing the catheter, and plugging the VAD. 
     Thus, in one aspect of the present disclosure, a method of implanting a blood pump in a heart of a mammalian subject includes maintaining a temporary plug in an inlet opening of a pump having a pump body and an outlet cannula projecting from the pump body. The method desirably also includes advancing the pump into a ventricle of the heart through a hole in a wall of the heart so that the inlet of the pump is disposed within the ventricle and the outlet cannula extends through a valve of the heart into an artery, and withdrawing the temporary plug from the inlet of the pump. 
     Additionally, the method may include mounting a ring to the wall of the heart and forming the hole in the wall of the heart within the ring. Also, the step of advancing the pump may include advancing a pedestal mechanically connected to the pump into the hole and into the ring, and securing the pedestal to the ring. The temporary plug may be mounted on an elongated catheter and the catheter may extend through a channel in the pedestal when the pump is advanced into the ventricle. Further, the step of withdrawing the temporary plug may include withdrawing the catheter and the plug through the channel in the pedestal and then closing the channel. 
     Continuing with this aspect, the step of maintaining the temporary plug may include maintaining the temporary plug in an expanded condition, and the step of removing the plug may include collapsing the plug. The plug may include a balloon. Also, the step of maintaining the temporary plug in an expanded condition may include maintaining the balloon in an inflated condition, and the step of collapsing the temporary plug may include deflating the balloon. 
     The method may also include purging the pump and the outlet cannula of air by allowing air to escape from the pump and the outlet cannula through the catheter while the outlet cannula is at least partially positioned within the heart or artery. Further, the method may include measuring pressure in the heart or artery using a pressure measurement instrument communicating with the interior of the pump through the catheter. 
     The ventricle may be the left ventricle and the valve may be the aortic valve. In addition, the steps of the method may be performed without cardiopulmonary bypass or cardioplegia. 
     In another aspect of the present disclosure, a pump installation kit comprises a pump including a pump body having an interior and an inlet communicating with the interior, a pumping element mounted within the interior, and an outlet cannula communicating with the interior of the pump body. The pump is desirably adapted for mounting with the pump body and inlet disposed within a ventricle of a heart. The kit preferably includes a temporary plug which is adapted for releasable, sealing engagement in the inlet. 
     Additionally, the kit may include a securement/mounting ring adapted for mounting to the outside of the heart, and a pedestal adapted for mounting to the securement ring. The pedestal may be mechanically coupled to the pump. When the pedestal is mounted to the securement ring, the pedestal may have a channel having proximal and distal ends. The distal end of the channel may communicate with the ventricle, and the proximal end of the channel may be disposed outside of the heart. 
     Continuing with this aspect, the kit may include an elongated element mechanically connected to the temporary plug. The elongated element may extend through the channel when the temporary plug is engaged in the inlet. The temporary plug may be adapted to pass out of the heart through the channel after the temporary plug is disengaged from the inlet port. The temporary plug may have an expanded condition and a collapsed condition, and the temporary plug may be adapted to pass out through the channel in the collapsed condition. The elongated element may be a catheter having an inflation lumen, and the temporary plug may include a balloon communicating with the inflation lumen. Also, the elongated element may be a catheter having a fluid lumen. The fluid lumen may communicate with the interior of the pump when the temporary plug is engaged in the inlet port. A pressure measuring instrument may be connectable to the fluid lumen 
     Furthermore, the kit may include a closure adapted to seal the channel in the pedestal. The closure may include a screw adapted to threadedly engage the channel. A resilient seal may be disposed within the channel. The resilient seal may sealingly engage the elongated element and the pedestal when the elongated element is disposed within the channel. The resilient seal may be a one-way valve adapted to prevent blood flow from the proximal end of the channel when the elongate element is removed therefrom. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings in which: 
         FIG. 1  is an elevational view of a transapical VAD implantation kit including a ventricular assist device and a catheter according to one embodiment of the present disclosure. 
         FIG. 2  is a partially sectional view depicting elements of the kit of  FIG. 1 . 
         FIGS. 3-8  are perspective views depicting steps in a method of implantation using the kit of  FIG. 1 . 
         FIG. 9  is a partially transparent perspective view of another embodiment of a transapical VAD implantation kit. 
     
    
    
     DETAILED DESCRIPTION 
     As used herein, when referring to the disclosed devices, the term “proximal” means closer to the operator or in a direction toward the operator and the term “distal” means more distant from the operator or in a direction away from the operator. Also, as used herein, the terms “about,” “generally,” and “substantially” are intended to mean that slight deviations from absolute are included within the scope of the term so modified. 
       FIG. 1  depicts a transapical VAD installation kit  10  according to one embodiment of the present disclosure. Installation kit  10  generally includes a transapical VAD and a catheter  50 . The transapical VAD delivers blood flow in line with the native heart and eliminates the need for CPB, cardioplegia, or an outflow graft to the aorta or pulmonary artery. The transapical VAD is generally comprised of a pump  12  and a pedestal  40  mechanically coupled to pump  12  via an elongate member  14 . 
     Pump  12  may be generally as shown in the &#39;957 Publication. It includes a pump body  30 . Pump body  30  includes a tubular housing  37  defining an inlet port  34  at a proximal end of pump body  30  and an outlet port  35  at a distal end of pump body  30 . A rotor  36  or axial flow impeller having a plurality of blades projecting outwardly therefrom is rotatably disposed within tubular housing  37 . Rotor  36  may be formed from a unitary piece of magnetizable, biocompatible material, such as biocompatible platinum-cobalt or platinum-cobalt-boron alloy. Rotor  36  may be magnetically or hydrodynamically levitated within housing  37 . During operation, rotor  36  is rotatable about an axis thereof by a motor stator  38  that is disposed about tubular housing  37  in order to urge fluid from inlet port  34  to outlet port  35 . Motor stator  38  is configured to provide a rotating magnetic field and preferably contains magnetic laminations and wire coils. An exterior shroud  32  surrounds housing  37  and motor stator  38 . Shroud  32  may be formed from any biocompatible material including, but not limited to, titanium, ceramic or polymer. Additionally, shroud  32  may be coated by a thromboresistant coating or other hemodynamically suitable coating. 
     Pump  12  also includes an outflow cannula  20  extending distally from outlet port  35  of pump body  30 . Cannula  20  may be made from any biocompatible material including, but not limited to, metallic and/or polymeric materials, such as thermoplastic polyurethanes, silicone, polycarbonate-urethanes, polyether-urethanes, aliphatic polycarbonate, titanium, barium sulfate, and any combinations thereof. Additionally, cannula  20  may include radiopaque materials incorporated into its structure at particular locations along the length of cannula  20  to allow for radiographic determination of the cannula&#39;s positioning relative to the patient&#39;s anatomy. For example, as shown in  FIG. 2 , cannula  20  may include a radiopaque bead  26 , such as a titanium or platinum bead, embedded within its structure at a distal end thereof, which may help with fluoroscopic visualization. 
     Outflow cannula  20  may be straight or bent and is generally a hollow, elongate structure that is dimensioned for partial placement into an aorta or pulmonary artery while pump body  30  is positioned in the left or right ventricles, respectively. A cross-sectional dimension of outflow cannula  20  may taper from pump body  30  such that the cross-sectional dimension near pump body  30  is larger relative to the cross-sectional dimension farther from pump body  30 . For example, cannula  20  may have a larger diameter near pump body  30  and a smaller diameter at a distal end of cannula  20 . 
     The distal end of cannula  20  is defined by a distal tip  24  that includes one or more outflow openings  22  communicating with the interior of pump body  30 . Outflow cannula  20  preferably also may include internal vanes (not shown), which convert rotational momentum of blood leaving rotor  36  into useful pressure. In some embodiments, the vanes may be located proximal to distal tip  24  or may be included in pump body  30  downstream of or distal to rotor  36 . 
     Pedestal  40  is generally a cylindrical member having a proximal to distal axis (not shown). Exemplary pedestals and methods of implantation can be found in U.S. Patent Application Publication 2015/0038770, the disclosure of which is hereby incorporated herein by reference in its entirety. Pedestal  40  includes an electrical connection  16  that is coupled to a power source and/or controller disposed outside of the heart. Electrical connection may enter into a proximal end of pedestal  40  in a transverse direction with respect to the proximal to distal axis of pedestal  40 . Electrical connection  16  may be rerouted within pedestal  40  so that electrical connection  16  extends in a generally axial direction along the longitudinal axis of pedestal  40  and through elongate member  14  into pump body  30  where it is electrically coupled to motor stator  38 . 
     A channel  42  may extend into a proximal end of pedestal  40  and exit through a distal end thereof. Channel  42  preferably has a diameter dimensioned to receive an elongate catheter therein. Additionally, pedestal  40  may be positioned respective to pump  12  such that channel  42  is coaxial with a bore of pump housing  37 . A resilient seal  44  may be disposed within channel  42  to serve as a temporary seal of channel  42 . For example, resilient seal  44  may be a one-way valve press-fit into channel  42 . Resilient seal  44  may be configured to prohibit blood from passing proximally within channel  42 . For example, resilient seal  44  may have leaflets that open in one direction. In addition, resilient seal  44  may be configured to allow catheter  50  to be passed through channel  42  in a proximal to distal direction and removed therefrom in the opposite direction, as described further below. In addition, resilient seal  44  may be configured to engage catheter  50  when disposed within channel  42  and to provide a seal around catheter  50 . For example, resilient seal  42  may be made from a flexible yet resilient biocompatible material that biases toward a closed or contracted condition. In addition, channel may narrow  42  at a location distal to resilient seal  44  so as to prevent resilient seal  44  from being dislodged from pedestal  40  in a distal direction. In another embodiment, seal  44  may contract around catheter  50  to provide a temporary seal while catheter is disposed within channel  42  but may not seal channel  42  when catheter  50  is removed therefrom. 
     Channel  42  may be internally threaded at or near the proximal end of pedestal  40 . Such threading may correspond to threading of a removable closure  46  (see  FIG. 8 ), such as a screw. However, alternative engagement features other than threading are contemplated, such as a Morse taper, for example. As discussed below, removable closure  46  sealingly engages pedestal  40  within channel  42  after removal of the catheter to permanently seal or plug the proximal end of pedestal  40  and provide redundancy to resilient seal  44 . 
     Pedestal  40  may serve as an intermediary between an external power supply and/or controller and pump body  30 . In addition, pedestal  40  may serve as a support structure for attachment to a ventricular wall of the heart. Pedestal  40  may be made from any biocompatible material including titanium, ceramic or polymer. In addition, pedestal  40  may include a sintered coating on an outer surface thereof to promote tissue ingrowth/attachment. The outer surface may also have engagement features (not shown) for engaging sutures attached to a mounting ring to help further secure pedestal to a ventricular wall. 
     Catheter  50  is generally an elongate structure that includes a plurality of input/output lines  52 ,  54 , a transition region  56  and a catheter body  58  that defines a plurality of individual lumens  55 ,  57  therein. Input/output lines  52 ,  54  converge and couple to catheter body  58  at transition region  56 . Each input/output line  52 ,  54  communicates with a respective lumen  55 ,  57  within catheter body  58 . Catheter body  58  may also include an expandable element  59  at a distal end thereof that has an expanded condition and a collapsed condition. As discussed below, when the expandable element  59  is in the expanded condition, it serves as a temporary plug that seals inlet port  34  of pump body  30 . One example of such catheter is a Swan-Ganz® catheter (Edwards Lifesciences Corp., Irvine, Calif.). 
     In one embodiment, which is depicted in  FIG. 2 , catheter  50  may include a first input/output line or inflation line  52 , which communicates with an inflation lumen  55  within catheter body  58 . Additionally, catheter  50  may include a second input/output line or fluid line  54 , which communicates with a fluid lumen  57  within catheter body  58 . In addition, expandable element  59  is located at the distal end of catheter body  58  and takes the form of an inflatable balloon, which when inflated, surrounds a circumference of catheter body  58 . Inflation lumen  55  communicates with balloon  59  such that a device, such a syringe, can be attached to inflation line  52  and deliver air or saline solution to balloon  59  via inflation lumen  55  in order to inflate balloon  59  into the expanded or inflated condition. Conversely, the air or saline solution can be withdrawn from balloon  59  and inflation lumen  55  to deflate balloon  59  into the collapsed or deflated condition. In the inflated condition, balloon  59  may seal inlet port  34  of pump  30 , and in the deflated condition, catheter body  58  may be removed from pump  30  and channel  42  of pedestal  40 . 
     Fluid lumen  57  communicates with an opening (not shown) at the distal end of catheter body  58 . Such opening is preferably located beyond or distal to balloon  59 . A device, such as a syringe, can be attached to fluid line  54  so that air and/or blood that is disposed beyond or distal to balloon  59  can be drawn through fluid lumen  57 . For example, when balloon  59  is in an inflated condition and seals inlet port  34  of the pump, fluid lumen  57  can be used to de-air and prime pump  12 . 
     Other lumens and corresponding individual lines for performing additional functions are also contemplated. For example, a third input/output line or sensor line (not shown) in communication with a sensor lumen within catheter body  58  may house a wire communicating with a pressure transducer disposed within fluid lumen  57  or on an exterior of catheter body  58  at a location distal to the temporary plug formed by expanded balloon  59 . Such sensor line and corresponding lumen can be coupled to a processor that is capable of converting signals received from the pressure transducer into pressure measurements of a fluid disposed within fluid lumen  57 . Alternatively, in one embodiment, the sensor lumen may communicate with another opening located at the distal end of catheter body  58  and sealed by a diaphragm. Deflection of the diaphragm can be measured to determine pressure of a fluid disposed at the distal end of catheter body  58 . In a further embodiment, fluid line  54 , or another fluid line, can be coupled to a pressure transducer, which may be located outside of the patient&#39;s body during implantation. In such embodiment, the externally situated pressure transducer can measure pressure at a distal opening of the catheter by sensing pressure of a fluid disposed within fluid lumen  57  and fluid line  54 . Other known configurations used to measure physical conditions via a catheter are also contemplated. 
     In an alternative embodiment (not shown) of catheter  50 , first line  52  and first lumen  55  may house a wire coupled to a distal tip of the catheter body  58 . A sidewall of catheter body  58  at the distal end thereof may be configured to buckle and expand outwardly in the shape of disc upon the tensioning of the wire at the proximal end of catheter  50 . Such configuration may be an alternative expandable element to an inflatable balloon. 
       FIGS. 3-7  depict an exemplary method of implanting pump  12  into a heart via kit  10 . Such method generally includes gaining access to the apex of the heart, attaching a mounting ring  80  to the apex, coring the left ventricular wall through mounting ring  80 , partially inserting pump  12  into the left ventricle, de-airing pump  12  via catheter  50 , continuing insertion of pump  12  into the left ventricle, measuring pressure sensed by catheter  50 , determining when the pressure measurements indicate that outflow cannula  20  is partially positioned within the ascending aorta, affixing pedestal  40  to the ventricular wall, deflating and removing catheter  50 , and plugging pedestal  40  via the removable closure  46 . 
     More particularly, prior to implantation of pump  12  into the left ventricle, catheter  50  is assembled with the transapical VAD by inserting catheter body  58  in a proximal to distal direction through pedestal channel  42  and resilient seal  44  such that the distal end of catheter body  58  extends into inlet port  34  of pump body  30 . This may be done in the operating theater or performed in the manufacturing facility in order to pre-assemble kit  10  prior to shipment to the healthcare facility. 
     A syringe, or other device, is coupled to inflation lumen  52  and air or saline solution is delivered through inflation lumen  52  from the syringe to balloon  59 , thereby expanding balloon  59  into its inflated condition within inlet port  42 . In the inflated condition, balloon  59  serves as a temporary plug within inlet port  34 . As such, rotor  36  and outflow cannula  20  are sealed from inlet port  34 . Only openings  22  of outflow cannula  20  can communicate with an environment external to pump  12 . 
     Thereafter, or concurrently with assembly of catheter  50  with the transapical VAD, an operator gains access to the heart preferably via a left subcostal or left thoracotomy incision to expose the apex of the heart. A mounting ring  80 , which may be provided as part of implantation kit  10  along with a coring instrument  90 , is attached to the apex via a pledgeted purse string suture, mattress suture, or the like (best shown in  FIG. 3 ). Examples of suitable mounting rings, coring instruments, and methods of using same can be found in U.S. Patent Application Publication No. 2007/0167968, the disclosure of which is hereby incorporate by reference. Other examples of mounting rings, including mounting rings that include leafleted valves, can be found in U.S. Patent Application Publication No. 2015/0112120, the disclosure of which is hereby incorporated by reference. In addition, examples of implanting a transapical VAD through a cored opening in the left ventricle can be found in the heretofore referenced &#39;957 publication. 
     A slit incision or incision in the form of a cross or X, commonly referred to as a “crux” incision, is made within mounting ring  80 , through the ventricular wall and into the left ventricle. Coring instrument  90  is inserted through the crux incision and ventricular wall tissue is resected from the heart via coring instrument  90  to form a cored opening  70  (best shown in  FIGS. 4 &amp; 5 ). Although, it is described that mounting ring  80  is applied before coring the apex of the heart, it should be understood that other techniques in which a mounting ring is applied after cored opening  70  is formed is also applicable. 
     While maintaining balloon  59  in the expanded configuration, pump  12  is advanced at least partially into the cored opening  70  (best shown in  FIG. 5 ). Such advancement can be performed quickly to help limit blood loss. Also, the operator may manually block the cored opening while maneuvering outflow cannula  20  into the opening. Blood loss can also be mitigated by a leafleted mounting ring, such as those described in the aforementioned &#39;120 Publication and by other implantation device, examples of which can be found in U.S. Provisional Application No. 62/089,910, the disclosure of which is hereby incorporated by reference in its entirety. 
     Air may be trapped within pump  12  beyond or distal to inflated balloon  59 . This air is removed to de-air outflow cannula  20  and pump body  30  via another device, such as a syringe, attached to fluid line  54  of catheter  50 . Fluid line  54  and fluid lumen  57  communicate with a distal opening beyond or distal to inflated balloon  59 . Negative pressure is applied to fluid line  54  and fluid lumen  57  via the device which in turn applies negative pressure to the pump distal to balloon  59 . As such, the air located within pump  12  is drawn out of the pump and is replaced by blood. Blood entering into the device coupled to fluid line  54  indicates that pump  12  has been sufficiently de-aired. De-airing removes air that can be potentially dangerous to the patient and also primes pump  12  with blood so that pump  12  can operate effectively upon startup. Inflated balloon  59  helps prevent retrograde blood flow and blood loss during advancement of pump  12 . In addition, inflated balloon  59  helps create an environment within pump  12  effective to determine blood pressure at the distal tip of outflow cannula  20 . 
     The de-aired pump  12  is then advanced through the left ventricle. As pump  12  is advanced through the left ventricle, blood pressure may optionally be sensed by a pressure transducer located within catheter  50  and monitored by the operator. Although, the pressure transducer or sensing location of the pressure transducer may be located in the distal end of catheter body  58  proximal to rotor  36 , the blood pressure detected by the sensor is substantially the same as that located at distal tip  24  of outflow cannula  20 . As previously mentioned, openings  22  of outflow cannula  20  are the only openings through which the inside of pump  12  communicates with the outside environment while inlet port  34  is plugged by balloon  59 . Thus, the blood pressure within outflow cannula  20  and pump body  30  is substantially the same as the blood pressure located at openings  22  of distal tip  24 . There may be a small offset between pressure sensed by the pressure transducer and pressure at distal tip  24  of outflow cannula  20 . However, such offset is minimal particularly in comparison to the differences between ventricular pressure and aortic pressure, which is significant. Thus, the operator can use the pressure measurements taken by the pressure transducer, particularly a measured difference between ventricular pressure and aortic pressure, to determine the location of distal tip  24  relative to the patient&#39;s anatomy. 
     Thus, as illustrated by the pressure wave shown in  FIG. 6 , as de-aired pump  12 , and in particular distal tip  24  of outflow cannula  20 , is advanced through the left ventricle, the monitored pressure may indicate when distal tip  24  is located in the ventricle and when it extends through the aortic valve into the aorta. More specifically, a transition of distal tip  24  from the ventricle to the aorta may be indicated by a change in the morphology of the waveform. Another indication can be a change in pressure values, which may be interpreted irrespective of the actual values outputted by the sensor. An even further indication may be a pressure value itself, rather than a change in value, which may be understood by the operator to be a pressure value associated with the aorta and not the ventricle, and vice versa. Also, as illustrated by  FIG. 7 , the operator may confirm the location of distal tip  24  via fluoroscopy. Thus, catheter  50  helps provide additional confirmation of the location of distal tip  24  relative to the patient&#39;s anatomy aside from the usual technique of fluoroscopic imaging. 
     Once distal tip  24  is properly located within the ascending aorta between the aortic root and aortic arch, pedestal  40  can be attached to the ventricular wall. This may be performed by attaching pedestal  40  to the mounting ring  80  as is known in the art, such as by clamping pedestal  40  with mounting ring  80 , for example. At this point, catheter  50  preferably remains within channel  42  of pedestal  40  and, along with resilient seal  44 , seals channel  42  during attachment, which helps prevent retrograde blood loss through pedestal  40 . 
     Once pedestal  40  is properly secured, balloon  59  of catheter  50  is deflated or collapsed, which may be performed by withdrawing air or saline solution therefrom. Catheter  50  is pulled proximal to pedestal  40  and catheter body  58  advanced through channel  42  in a distal to proximal direction. Catheter body  58  is withdrawn from inlet port  34  and from channel  42  of pedestal  40 . Once catheter body  58  is advanced to a proximal location beyond resilient seal  44 , resilient seal  44  closes to provide a one-way temporary seal until channel  42  can be permanently plugged. Channel  42  is permanently plugged by threading or otherwise sealingly engaging the proximal end of channel  42  with closure  46  (best shown in  FIG. 8 ). Pump  12  may then be activated and the access incision closed. 
       FIG. 9  depicts an alternative transapical VAD implantation kit  100 . Kit  100  includes a VAD having a pedestal  140 , pump body  130 , and outflow cannula  120  similar to that of kit  10 , but differs with respect to the catheter  150 . Catheter  150  includes an expandable element/balloon  159  that may be cylindrical and dimensioned to tightly/sealingly fit within the space between pedestal  140  and pump body  130  when expanded into an expanded condition. Thus, balloon  159 , when expanded, can occlude an inlet of pump body  130  without being disposed therein. In addition, when expanded, balloon  159  may have a diameter as large as that of pedestal  140  and/or pump body  130 , and when deflated may have a diameter sufficiently small to slide through a channel within pedestal  140 . 
     Catheter  150  may include balloon  159  in addition to a distal balloon, which may be similar to that of balloon  59  described above and may be configured for placement within the inlet of pump body  130 . In such an embodiment, catheter  150  may include a second inflation lumen to feed balloon  159  so that balloon  159  is separately expandable from the distal balloon. Alternatively, balloon  159  may be the only balloon provided with catheter  150 . 
     Balloon  159  helps fill the space between pedestal  140  and pump body  130 , which can help reduce blood loss during implantation as it helps prevent blood from flowing around pump body  130  and out of a cored opening in the heart. In other words, as pump body  130  is inserted through a cored opening in the heart, pump body  130  may at least partially occlude the cored opening. However, once pump body  130  is fully inserted into the ventricle but prior to pedestal  140  being placed within the cored opening, blood may flow around pump body  130  into the space between pedestal  140  and pump body  130  and out of the cored opening. Balloon  159  fills this space and helps occlude the cored opening until pedestal  140  is inserted therein. 
     EXAMPLE 
     Transapical ventricular assist devices were implanted in healthy bovine (n=4) via a thoracotomy without use of CPB. A Swan-Ganz balloon catheter was inserted into an access channel inside the pedestal and advanced into the pump inflow. A mounting ring was attached at the LV apex and the pump was inserted after coring to form a hole in the wall of the heart. Once the pump was fully inserted through the mounting ring and through the hole in the heart-wall formed by coring, the mounting ring was mechanically engaged with the pedestal so as to hold the pump in place. In this condition, the pedestal and sealing ring closed the hole in the heart wall. The balloon was inflated during pump insertion to prevent retrograde flow through the pump. The fluid lumen of the catheter was used to de-air the pump and was connected to a fluid pressure line and thus to a pressure measuring instrument. Pressure waveforms were monitored during insertion to verify positioning in LV and across the aortic valve. After pump insertion, the balloon was deflated and the catheter was retracted so as to remove the balloon and catheter from the heart through the channel in the pedestal. The proximal end of the channel disposed outside the heart was sealed with a closure in the form of a plug threadedly engaged in the channel. 
     Results 
     Average implant time of 5 minutes from LV coring to pump start with less than 50 mL of blood loss was achieved. Swan-Ganz balloon inflation successfully prevented backflow of blood through the pump during insertion. Fluoroscopic images confirmed cannula placement across the aortic valve and pump alignment along the LV outflow tract. 
     Although the above methods and techniques are described in relation to the implantation of pump  12  into the left ventricle, it should be understood that pump  12  can be implanted into the right ventricle with outflow cannula  20  extending into the pulmonary artery. In addition, it should be understood that catheter  50  can be used in conjunction with other pumps and other delivery approaches without departing from the principles described herein. 
     Also, while the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.