U.S. patent application number 13/122394 was filed with the patent office on 2012-09-27 for device and a method for augmenting heart function.
Invention is credited to Jan Otto Solem.
Application Number | 20120245678 13/122394 |
Document ID | / |
Family ID | 44673459 |
Filed Date | 2012-09-27 |
United States Patent
Application |
20120245678 |
Kind Code |
A1 |
Solem; Jan Otto |
September 27, 2012 |
Device And A Method For Augmenting Heart Function
Abstract
A device, a kit and a method are presented for permanently
augmenting the pump function of the left heart. The basis for the
presented innovation is an augmentation of the physiologically up
and down movement of the mitral valve during each heart cycle. By
means of catheter technique, minimal surgery, or open heart surgery
implants are inserted into the left ventricle, the mitral valve
annulus, the left atrium and adjacent tissue in order to augment
the natural up and down movement of the mitral valve and thereby
increasing the left ventricular diastolic filling and the piston
effect of the closed mitral valve when moving towards the apex of
said heart in systole and/or away from said apex in diastole.
Inventors: |
Solem; Jan Otto; (Bjarred,
SE) |
Family ID: |
44673459 |
Appl. No.: |
13/122394 |
Filed: |
March 25, 2011 |
PCT Filed: |
March 25, 2011 |
PCT NO: |
PCT/SE11/50338 |
371 Date: |
October 18, 2011 |
Current U.S.
Class: |
623/2.36 ;
623/3.11 |
Current CPC
Class: |
A61M 1/1081 20130101;
A61M 1/127 20130101; A61M 1/1087 20140204; A61F 2/2412 20130101;
A61M 1/1068 20130101; A61M 1/1008 20140204; A61M 1/1053 20130101;
A61M 1/122 20140204; A61F 2/2409 20130101; A61M 1/1055 20140204;
A61F 2/2436 20130101; A61F 2/2457 20130101; A61F 2210/009 20130101;
A61F 2/2445 20130101; A61M 1/12 20130101 |
Class at
Publication: |
623/2.36 ;
623/3.11 |
International
Class: |
A61F 2/24 20060101
A61F002/24; A61M 1/10 20060101 A61M001/10 |
Claims
1. A medical device for assisting left ventricular pump action in a
human heart, said device comprising: a displacement unit; said
displacement unit adapted to assist movement of a mitral valve in a
mitral valve plane substantially along a long axis of a left
ventricle of said heart, said displacement unit being an implant in
said heart for contact with said mitral valve; said displacement
unit being operable to move said mitral valve in a reciprocating
manner along said long axis towards an apex of said heart during
systole and along said axis away from said apex during
diastole.
2. The device of claim 1, wherein said displacement unit includes a
mechanical unit applying a mechanical supporting force to the
mitral valve during at least one of systole and diastole.
3. The device of claim 2, wherein said mechanical unit has a
proximal end portion attachable to the mitral valve and a distal
end portion that is in communication with an energy converter unit,
said energy converter unit operable to transfer energy from a
remote energy source into a force providing said mechanical
supporting force.
4. The device of claim 3, wherein said proximal end portion is
configured for attachment to a mitral valve annulus.
5. The device of claim 4, wherein said proximal end portion
includes a fixation unit, said fixation unit being partly
loop-shaped for fixation to the mitral valve annulus; said fixation
unit having an extension unit protruding from said fixation unit
towards a coaptation line of said mitral valve, and wherein said
mechanical unit is configured for attachment to said fixation unit
at said extension unit at said coaptation line.
6. The device of claim 4, wherein said proximal end portion
includes a fixation unit, said fixation unit being partly
loop-shaped for fixation to the mitral valve annulus, and wherein
said mechanical unit is configured for attachment to said fixation
unit at a circumference of said fixation unit, wherein said
mechanical unit is adapted to penetrate said mitral valve at the
mitral valve annulus at least behind the posterior leaflet of the
mitral valve.
7. The device of claim 1, wherein said displacement unit comprises
a magnetic unit applying a magnetic supporting force to the mitral
valve during at least one of systole and diastole.
8. The device of claim 7, wherein said magnetic unit comprises a
plurality of magnetic anchors, including a first, proximal magnetic
anchor and a second, distal magnetic anchor said first and second
magnetic anchors being selectively magnetic relative each other,
wherein said first anchor is configured for placement at the mitral
valve, and the second anchor is configured for placement remote
from the first anchor.
9. The device of claim 8, wherein one of said magnetic anchors is
an electromagnet that controllably changes polarity synchronized
with the heart cycle.
10. The device of claim 8, wherein one of said magnetic anchors is
a loop shaped annuloplasty implant.
11. The device of claim 8, wherein another of said magnetic anchors
is implantable in a heart septum and configured for occluding an
opening in said septum.
12. The device of claim 8, wherein another of said magnetic anchors
implantable in the left atrial appendage (LAA) and is configured to
occlude said LAA.
13. The device of claim 1, further comprising an energy source
positioned remotely from said displacement unit and in
communication with said displacement unit so as to provide energy
causing movement of said displacement unit and thereby movement of
said mitral valve in said mitral valve plane along said long
axis.
14. The device of claim 13, further comprising an extended
connecting unit transferring mechanical movement energy to said
displacement unit using energy from said remote energy source.
15. The device of claim 13, wherein said displacement unit
comprises an actuator connected to said remote energy source with a
wire that communicates electrical energy from said remote energy
source to said actuator.
16. The device of claim 1, wherein said displacement unit is an
implant for fixation to a native mitral valve.
17. The device of claim 1, wherein said displacement unit is an
implant for fixation to a replacement valve.
18. The device of claim 17, wherein said replacement valve
comprises a hollow frame having a longitudinal extension, wherein
said frame is configured to be oriented in said heart perpendicular
to said mitral valve plane and configured to be affixed to the
mitral valve annulus, and wherein said frame is housing a plurality
of valve leaflets, and wherein said frame is connected to said
displacement unit for said movement.
19. The device of claim 17, wherein said displacement unit
comprises a housing in which said replacement valve is movably
received, said housing having a longitudinal extension configured
to be oriented in said heart perpendicular to a mitral valve plane
and configured to be affixed to the mitral valve annulus at a
mitral valve annulus attachment.
20. The device of claim 1, further comprising an anchor unit having
a foldable mitral valve annulus anchor unit affixable to said
mitral valve annulus.
21. The device of claim 1, wherein said displacement unit is
bistable between a diastolic up position and a systolic down
position relative to said mitral valve plane and is movable
therebetween according to an external energy source controllably
provided to said displacement unit.
22. The device of claim 1, wherein said device further comprises; a
remote energy source; a control unit and a sensor operatively
connected to said control unit; said sensor configured for
measuring physiological parameters related to a cardiac cycle
activity so as to provide a sensor signal to said control unit such
that said control unit is adapted to control movement of said
displacement unit using energy from said remote energy source based
on said sensor signal.
23. The device of claim 22, wherein said remote energy source
includes a mechanical section and an extension unit, said extension
unit positioned between said mechanical section and said
displacement unit, said mechanical section operable to generate
mechanical motion that is transferable to said displacement unit
for said movement via said extension unit.
24. The device of claim 22, wherein said remote energy source is
controlled by said control unit to provide electrical energy to one
of at least one electromagnetical anchor units affixed in relation
to said mitral valve and one of at least one actuator arranged in
the heart so as to provide said movement of said mitral valve
plane.
25. The device of claim 22, wherein said remote energy source is
implantable in the fatty tissue under the skin adjacent to a
vessel.
26. The device of claim 1, wherein said device further comprises a
control unit which operatively controls said displacement unit to
provide a set sequence of said reciprocating movements.
27. The device of claim 26, wherein said control unit is configured
to set at least one of a frequency, a speed, and a pause time
duration of said reciprocating movements in said set sequence.
28. A kit comprising a device of claim 1, and a delivery system for
said device, including an introducer catheter with a valve, a
guiding catheter, a guide wire and at least one delivery
catheter.
29. A method of delivering a medical device adapted to enhance
intra-cardiac blood circulation of a heart of a patient, said
device having a displacement unit adapted to controllably move a
mitral valve in a mitral valve plane substantially along a long
axis of a left ventricle of said heart, said displacement unit
being an implant in said heart for contact with said mitral valve;
said displacement unit being operable to move said mitral valve in
a reciprocating manner along said long axis towards an apex of said
heart during systole and along said axis away from said apex during
diastole, said method comprising providing a medical system
including said medical device and an energy source, and surgically
delivering said medical system in said patient.
30. The method of claim 29, wherein said method comprises providing
a delivery system, such as said kit according to claim 28, for
minimally invasively delivering said medical device in said
patient, and minimally invasively delivering said displacement unit
of said medical system in said patient by means of said delivery
system, delivering said energy source, and connecting said energy
source and said displacement unit.
31. The method of claim 30, wherein said delivery system includes
an introducer catheter with a valve, a guiding catheter and a guide
wire, and wherein said method comprises introducing said introducer
catheter at a puncture site into the vascular system of said
patient, inserting said guide wire into said vascular system via
said introducer catheter, navigating through the vasculature and
the heart to a desired site, inserting said guiding catheter over
said guide wire, withdrawing said guide wire, through said guide
catheter delivering a first anchor unit at a distance from a mitral
valve and delivering a second anchor unit at said mitral valve.
32. The method of claim 30, wherein said delivery system includes
an introducer catheter with a valve, a delivery catheter and a
pushing unit, a guide wire and a guiding catheter, wherein said
method comprises introducing said introducer catheter at a puncture
site into the vascular system of said patient, inserting said guide
wire into said vascular system via said introducer catheter,
navigating through the vasculature and the heart to a delivery
site, inserting said guide catheter over said guide wire, providing
an anchor unit at a distal end of said pushing unit, introducing
said distal end in front of said pushing unit into said delivery
catheter, and a) wherein said delivery catheter has a smaller outer
diameter than an inner diameter of the guiding catheter, and
longitudinally moving the delivery catheter in said guide catheter,
or b) retracting said guide catheter, and longitudinally moving the
delivery catheter over said guide wire previously placed at the
delivery site by means of the guide catheter; and activating said
anchor unit by means of pushing said pushing unit forward while the
tip of the delivery catheter has contact with the surface of
delivery site, such as the left ventricle wall, and allowing anchor
elements of the anchor unit, such as hooks or blades, to dig into
the tissue at said delivery site.
33. The method of claim 32, comprising threading an extension unit
through said delivery system and releasing a mitral valve annulus
anchor by retracting the catheter of the delivery system from over
the mitral valve annulus anchor, and attaching the mitral valve
annulus anchor to the mitral valve annulus.
34. The method of claim 29, comprising providing access to the
vascular system by puncturing a large vein, placing an introducer
catheter with a valve in the vein, through the introducer catheter
advancing a guide wire, and over the guide wire advancing a guide
catheter to the right atrium (4), obtaining access to the left
atrium by penetrating through an open foramen ovale or through the
inter-atrial wall and thereafter advancing the guiding catheter
into the left atrium, and advancing said guide catheter and the
guide wire into the left ventricle through the mitral valve to the
delivery site at the left ventricular wall, advancing a delivery
system for an anchor unit inside the guide catheter or over a guide
wire until its catheter opening has contact with the inner surface
of the left ventricular wall, advancing the pushing catheter and
pushing said anchor unit out of the catheter opening to dig into
the muscular tissue and pull the anchor unit inside said muscular
tissue, and thereby creating a secure anchoring of a pulling and
pushing unit, and retracting the delivery catheter and pushing
unit.
35. The method of claim 34, comprising advancing a delivery system
for a mitral valve annulus anchor over the pulling and pushing unit
until the anchor and its arms are adjacent to the mitral valve
annulus, and when in position, retracting the catheter over the
catheter until outside of the patient, allowing arms and their
attachments hooks to attach to the mitral valve annulus and dig
into the tissue.
36. The method of claim 35, adjusting the pushing and pulling unit
and the catheter in length and attaching these to the remote energy
source.
37. The method of claim 35, comprising positioning said remote
energy source in fatty tissue under the skin, adjacent to a vessel,
and optionally attaching the energy source to a bony structure.
38. The method of claim 29, wherein said method comprises providing
surgical access to the mitral valve, the mitral valve annulus and
the left ventricle including surgically opening the chest of a
human being and establishing extra corporeal circulation (ECC) or
manipulating the heart manually from the outside, while still
pumping.
39. The method of claim 29, comprising attaching a first anchor
unit in the musculature in the area of the left ventricular apex,
attaching a second anchor unit to the mitral valve annulus, and
connecting said two anchors to each other by means of a connecting
unit that may shorten and increase the length between the anchors,
and attaching the connecting unit to a remote energy source; or
replacing the mitral valve by an artificial valve serving as both
the mitral valve and the mitral annulus anchor.
40. A method for enhancing ventricular pump function of a heart of
a patient comprising: controllably assisting movement of a mitral
valve according to synchronization with a cardiac cycle of said
heart.
41. The method of claim 40, said method wherein said controllably
assisting movement comprises moving a mitral valve in said heart in
an assisted reciprocating movement during systole towards an apex
of said heart and during diastole away from said apex for assisting
said pump action of said heart.
42. The method of claim 41, further comprising detecting the
natural action of the heart and providing energy for displacement
of said mitral valve plane in synchrony with the natural heart
cycle.
43. The method of claim 42, further comprising providing a mitral
valve replacement valve.
44. The method of claim 43, wherein said replacement valve is
mounted in a housing, and moving said heart valve up and down in
said housing relative to a mitral valve annulus attachment.
45. The method of claim 41 further comprising providing a medical
device according to claim 1.
46. A system for permanently enhancing left ventricular pump
function of a heart of a patient, said system comprising a
displacement unit for controlled assisted mitral valve movement
synchronized with a cardiac cycle of said heart substantially along
a long axis of a left ventricle of said heart, said displacement
unit being configured to be arranged in said heart of said patient
and being in contact with said mitral valve to push and/or pull
said mitral valve such that said mitral valve moves in a by said
displacement unit assisted reciprocating movement during systole
towards an apex of said heart and/or during diastole away from said
apex for assisting pump action of said heart.
47. A computer-readable medium having embodied thereon a computer
program for processing by a computer for permanently enhancing left
ventricular pump function of a heart of a patient, said computer
program comprising a code segment for synchronizing assisted mitral
valve movement with a cardiac cycle of said heart.
Description
RELATED APPLICATIONS
[0001] This application is a U.S. National Stage Application based
on International Patent Application No. PCT/SE2001/050338 filed
Mar. 25, 2011 entitled A Device And A Method For Augmenting Heart
Function, which claims priority to U.S. Provisional Application
Ser. No. 61/317,631 filed Mar. 25, 2010, and Swedish application
Serial No. SE1050283-9 filed Mar. 25, 2010, both entitled Device
And A Method For Augmenting Heart Function, all of which are hereby
incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to an intra-cardiac blood
circulation enhancing apparatus, a system for intra-cardiac blood
circulation enhancement and a method for enhancing left ventricular
pump function of a patient. The present invention is in particular
applicable to enhance the pump function of the left ventricle,
including as a permanent measure for treating a heart failure
disease where the heart function is deficient.
BACKGROUND OF THE INVENTION
[0003] Where the heart function is chronically insufficient, there
may be a need to permanently aid the heart function. Heart failure
(HF), more often called Congestive Heart Failure (CHF), is in
general a condition where the heart is unable to support the body
tissue with its metabolic demands and to sustain adequate blood
pressure and cardiac output. The term Congestive relates to a
congestion of blood and fluids in front of the pumping ventricles
as a result of insufficient forward pumping, most often caused by
disease of the left ventricle muscle. A peculiarity of heart cells
is that they do not regenerate after damage or cell death, thus
conditions have a tendency to worsen rather than heal after heart
cell damage. There are many reasons for heart cell death, the most
common cause is ischemic heart disease, a condition where the
arteries feeding the heart muscle get clogged, causing myocardial
infarctions (MI). Viruses may damage the muscle cells, and some
diseases, for instance cardiomyopathy have unknown reasons. End
stage of long standing high blood pressure may also cause end stage
heart failure. Heart strengthening drugs like digoxin or treatment
with diuretics help for a while, but are all only treating
symptoms. CHF is a progressive untreatable, disabling and finally a
deadly condition. According to the American Heart Association
homepage, there are in the US at present more than 5 Million
patients living with CHF and 550 000 are added every year. 40000
patients in the US are in such a bad state that only a heart
transplant will keep them alive. However, due to the limited number
of suitable organs only 2500 transplants are done yearly in the US.
One may extrapolate the numbers for the rest of the industrialized
world.
[0004] Total artificial heart, where the whole native heart is
excised and replaced with a mechanical device was introduced in the
1960's by DeBakey, in the 1980's by among others Jarvik and
recently by Copeland (CardioWest, Total Artificial Heart). However,
these devices are still based on complex designs and are very
invasive to install in the patient. Failure in operation of the
device is fatal.
[0005] There are other techniques supporting only the failing left
ventricle, known as left ventricle assist devices (LVAD). The most
popular LVADS are the Novacor and the HeartMate devices. Common for
this devices is the demand for major open heart surgery utilizing
extracorporeal circulation by means of a Heart- and Lung-machine
while stopping (or excising) the heart. They are bulky devices, a
Novacor weights 1.800 grams, a HeartMate 1.200 grams. There are
smaller axial flow pumps available nowadays, the HeartMate II, the
Jarvik 2000 and the MicroMed DeBakey VAD. However, major open heart
surgery is still necessary to install and connect these devices to
the left ventricle cavity and the aorta by means of large vascular
grafts. The mentioned devices have almost exclusively been used as
a bridge to a heart transplant due to high frequency of
complications, some of which are caused by the large amount of
foreign material, high mortality and limited durability. Their use
has also been limited because of high prices of up to 150 000 $
only for the device.
[0006] In U.S. Pat. No. 5,957,977 an activation device for the
natural heart is disclosed. The activation device has a stint for
placement within the interior volume of a natural heart adjacent
cardiac tissue thereof. The device also includes a yoke for
placement around a portion of the exterior surface of the natural
heart in general alignment with the stint and connected to the
stint by at least one cord (surgical thread). By means of multiple
parts that are assembled during surgery, a cage is created where
half of the cage is inside the heart and the other half outside.
Within the cage a heart chamber, e.g. the left ventricle is
completely locked in. By means of hydraulic power underneath the
external part of the cage, compression on the chamber is achieved
from the outside. The inner half avoids that inner heart structures
may give away while compressing from the outside. However, the
device is very invasive, as it requires a connection between the
interior of the heart and the exterior of the heart. Moreover,
extensive open heart thoracic surgery is required to position the
device in the patient, none of which involves surgery of the mitral
valve. Furthermore, the device is not designed for action
synchronic with the natural heart cycle.
[0007] None of the devices for permanent implant previously
described are feasible for minimal invasive catheter based
insertion. On the contrary, they all involve major open heart
surgery. There is a need and demand for simpler devices. It is one
scope of the here presented invention to omit major cardiac surgery
and to allow positioning of an implant with catheter technique or
by minimal access surgery.
[0008] Moreover, health care is permanently searching for improved
devices and methods.
[0009] Hence, there is a particular need of an improved system
and/or method for permanently enhancing or assisting left
ventricular pump function of a heart of a patient. The system is
advantageously not interfering with the cardiac cycle of the heart.
Major open heart surgery is desired to be avoided. Even more
advantageous would be if at the same time leaking heart valves
could be repaired. It is also desired to avoid implantation of
large surfaces of foreign material in the heart. Advantageously,
the native valves, like the native mitral valve are preserved, when
enhancing cardiac pump function with such devices.
[0010] Hence, an improved system and/or method for permanently
enhancing or assisting left ventricular pump function of a heart of
a patient would be advantageous and in particular allowing for
increased flexibility, cost-effectiveness, long-term function,
and/or patient friendliness would be advantageous.
SUMMARY OF THE INVENTION
[0011] Accordingly, embodiments of the present invention preferably
seek to mitigate, alleviate or eliminate one or more deficiencies,
disadvantages or issues in the art, such as the above-identified,
singly or in any combination by providing a device, a system, and a
method according to the appended patent claims.
[0012] The here presented innovation is based on improved insight
how the left ventricle functions.
[0013] Modern imaging of the beating heart has contributed largely
to the understanding of left ventricle pump action. The pumping
force of the left ventricle has before been understood to be
totally a result of the heart muscle contracting and squeezing
(systole) around the amount of blood enclosed inside the left
ventricle after closure of the mitral valve, increasing the
pressure and thereby forcing the blood towards the aortic valve,
forcing this to open and ejecting the blood into the ascending
aorta. When the squeezing is completed, an intermission occurs
(diastole), during which a new portion of blood enters the left
ventricle cavity from the left atrium.
[0014] Ultrasound imaging and Magnetic Resonance Imaging (MRI) has
revealed that this previously taught mode of function is not
completely true. Instead, one may describe two types of pump
action, a long axis and a short axis action. MRI can show that
there is a movement of the atrioventricular mitral valve (MV) plane
downwards along the left ventricle long axis that extends from the
atrium towards the ventricle's lower end, the apex. The left
ventricle muscle cells are pulling the whole mitral valve plane,
including the mitral valve annulus and part of the left atrial wall
(that is stretching) towards the heart apex. By pulling the closed
mitral valve towards the heart apex, the mitral valve becomes a
piston in a blood displacement pump.
[0015] The downwards movement of the mitral valve is in a healthy
human up to approximately 2 centimetres. The downwards movement
accelerates the blood column away from the left atrium and towards
the aortic valve in a continuous movement. By means of MRI
technology one is able to virtually mark separate pixels inside the
blood column and follow their movement. It is possible to show that
the blood column flows more or less continuously from the left
atrium to the ascending aorta without ever stopping. The blood
column is accelerated by the mitral valve piston moving up and down
along the cardiac long axis, opening every time it takes a new
scoop of blood in an upward movement to the atrium, and closing
just before moving back toward the apex. One may estimate the
contribution of the long axis pump action of the heart to 30-50% of
the total heart pump function.
[0016] In congestive heart failure the downwards movement of the
mitral valve is impaired. It is the scope of the here presented
innovation to augment the long axis function of the heart by means
of improving the downwards and/or upwards movement of the mitral
valve. To our knowledge, nobody has before attempted to enhance the
up- and downwards movement of the mitral valve annulus by means of
implanting an augmenting device.
[0017] The embodiments of the invention provide improved left
ventricular pump action by means of external power in order to be
able to move the native MV along the long axis of the left
ventricle (LV) towards the heart apex, in synchrony with the
cardiac cycle. A synchronized reciprocating movement of the MV
valve plane is provided by various embodiments.
[0018] Major open heart surgery is avoided. Even when surgery would
be done to implant some embodiments of the here presented device,
it is limited to access the mitral valve annulus and the left
ventricle, also providing an opportunity to repair a leaking mitral
valve. The here described devices, systems and methods do not
involve implantation of large surfaces of foreign material and the
native mitral valve is in particular preserved in some
embodiments.
[0019] In some embodiments, modern catheter based technology is
integrated in the here described device, system and methods,
allowing deployment of the whole system or parts of it by means of
catheter technique.
[0020] According to one aspect of the invention, a medical device
is provided for enhancing intra-cardiac blood circulation of a
heart of a patient by assisting left ventricular pump action
thereof. The device includes a displacement unit that controllably
moves a mitral valve in a mitral valve plane substantially along a
long axis of a left ventricle of the heart. The displacement unit
is further configured to be arranged in the patient such that the
mitral valve is moved in a reciprocating movement during systole
towards an apex of the heart and during diastole away from the apex
for assisting the pump action of the heart.
[0021] The displacement unit is in use moving the closed mitral
valve during systole towards the heart apex and/or moving the
opening or opened mitral valve during diastole away from the heart
apex. The mitral valve thus becomes a supported piston in a blood
displacement pump. The downwards movement accelerates the blood
column away from the left atrium and towards the aortic valve in a
continuous movement. The range of movement of the thus supported
mitral valve along the long axis is up to approximately 2
centimetres in an adult patient. The range of movement is
correspondingly less in pediatric patients and especially in
patients with heart failure. The blood column acceleration by the
mitral valve piston is assisted by the displacement unit, helping
the mitral valve plane to move up and down along the cardiac long
axis in a desired manner. The valve opens every time it takes a new
scoop of blood in an assisted upward movement to the atrium, and
closes just before assisted moving back toward the apex in the next
systole. The assist movement provided by the displacement unit is
made synchronously with the cardiac cycle to optimize the cardiac
assist function provided.
[0022] In embodiments the displacement unit has a mechanical unit
devised to apply a supporting force to the mitral valve during
systole towards the apex, thus augmenting the (still existing)
natural pumping force of the heart while ejecting blood into the
aorta. In other embodiments the displacement unit includes a
mechanical unit devised to apply a supporting force to the mitral
valve away from the apex during diastole, augmenting the natural
filling of the left ventricle of a heart, and thus augmenting the
(still existing) natural pumping function of the heart by an
improved filling degree. In preferred embodiments the invention is
supporting the systolic as well as the diastolic function of a
heart in synchrony with the heart cycle. The total force supplied
to the mitral valve plane is the combined remaining natural force
of the heart and the supporting force provided by the displacement
unit.
[0023] This enhancement is done in a gentle way by supporting the
natural function of the heart. Congestive Heart Failure (CHF) is
effectively treated or prevented. Long term treatment is enabled.
Invasiveness is very limited. The amount of foreign material
implanted in the heart is very limited. Open heart surgery may not
be necessary for installing some embodiments of the cardiac assist
device.
[0024] In some embodiments, the mechanical unit has a proximal end
at which it is attached to a location of the mitral valve, such as
the mitral valve annulus. A distal end is attached to an energy
converter unit that transfers energy from a remote energy source
into a linear force and/or a rotational force for providing the
supporting force. The mechanical unit is for instance a pulling
and/or pushing unit. The pulling and/or pushing unit is attached to
a location in the heart related to the mitral valve, such as the
mitral valve annulus. The pulling and/or pushing unit is thereby in
operation augmenting the natural force of the heart and extends the
downwards and upwards movements of the mitral valve relative the
apex. The movement of the MV plane along the long axis is thus
supported, augmenting the natural force of the heart.
Alternatively, or in addition, the mechanical unit may be based on
other mechanical movement, such as a rotational, threaded, and/or
pivotal based arrangement to provide the supporting force for the
cardiac assist.
[0025] In some embodiments the mechanical unit is attached to the
mitral valve annulus by means of a fixation unit. The fixation unit
is for instance attached in a loop shaped manner, such as circular,
along at least a portion of the mitral valve annulus, like an
annuloplasty implant. The fixation unit may have the native form of
the annulus circumference where the leaflets are attached. The
annuloplasty implant may be provided in an annular (ring) shape,
D-formed shape, open ring C-formed shape, etc. Regurgitation may
thus be permanently treated conveniently by means of repair of a
mitral valve. Being part of the displacement unit, heart pumping
function is improved in a synergistic manner. The closing of the
mitral valve leaflets during systole is improved by the
annuloplasty, which in turn further improves the efficiency of the
supported pump function provided by the supported displacement of
the MV relative the apex.
[0026] Movable units of embodiments, like joints, etc. may be
suitably encapsulated to not be in contact with blood or cardiac
tissue to avoid any operational complications.
[0027] In some embodiments, the displacement unit has a plurality
of magnetic tissue anchors that are controllably and selectively
magnetic relative each other. A first anchor for instance located
at the mitral valve, and a second anchor is located remote from the
first anchor inside or outside the heart. This allows for a very
compact arrangement without moving parts from a remote energy
source. A controlled movement is for instance achieved by having at
least one of the anchors being an electromagnet that controllably
changes polarity synchronized with the heart cycle. One of the
magnetic anchors may be a monolithic unit, which is a combined
magnetic anchor and an annuloplasty implant (shape see above).
Magnetic functionality may be added by a coil unit. The coil unit
may be integrated with the annuloplasty implant. Alternatively, the
coil unit may be provided as a flange unit allowing for affixing
the annuloplasty implant or anchor unit to the annulus tissue in a
convenient manner.
[0028] The second magnet anchor may also be located in the atrial
or ventricular septum, wherein the second anchor unit may be
occluding an (natural) opening in the septum. The occluder anchor
may have two flange units for apposition to the septum on the left
respectively the right heart side with an interconnecting portion
of reduced diameter arranged in the opening. The occluder anchor is
made of a magnetic material or provided with electromagnetic
properties. Septal defects may thus be treated, and heart function
is improved conveniently in a synergistic manner. Septal occlusion
and supported MV movement, eventually with reduced regurgitation,
provide for optimized heart function.
[0029] The second magnet anchor may be located in the left atrial
appendage (LAA), wherein the second anchor unit is an LAA occluder.
The LAA occluder may have one or more retention flanges for safe
anchoring in the LAA. The LAA occluder anchor may have two flanges.
The occluder anchor LAA is made of a magnetic material or provided
with electromagnetic properties. LAA related diseases, such as
embolic events, may thus be treated conveniently at the same time
as supported heart function is provided. Heart diseases are thus
treated in a synergistic manner.
[0030] In embodiments the displacement unit is driven by energy
from an energy source providing the energy for the movement of the
mitral valve in the mitral valve plane along the long axis. The
energy is e.g. movement energy that is mechanically transferred
from a remote energy source to the displacement unit.
Alternatively, or in addition, the energy is electrical energy that
is transferred from the remote energy source via a cable to an
actuator of the displacement unit.
[0031] In the displacement unit the mitral valve may be a
replacement artificial valve that is moved along the long axis of
the left ventricle reciprocating towards the heart apex and away
therefrom in synchrony with the cardiac cycle. Cardiac assist
function may then be provided as in other embodiments by providing
a movement of the MV plane of the replacement valve along the LV
long axis. Alternatively, the replacement valve may be arranged to
move up and down in a support frame to provide the cardiac assist
reciprocating movement along the LV long axis.
[0032] In some embodiments an anchor unit of the displacement unit
is provided in form of a foldable mitral valve annulus anchor unit
affixable to the mitral valve annulus. The unit is thus retractable
into a catheter and minimal invasive procedures are
facilitated.
[0033] The displacement unit may be bistable between a stable
diastolic up position and a stable systolic down position of the MV
plane, wherein the displacement unit has an equilibrium state in
the up and down position respectively, and wherein the displacement
unit moves between the two stable positions when energy from an
external energy source is controllably provided to the displacement
unit in synchrony with the cardiac cycle. These embodiments may be
more energy efficient than others.
[0034] In embodiments the cardiac assist device has a control unit
and a sensor for measuring physiological parameters related to the
cardiac cycle activity providing a sensor signal. The sensor signal
is provided to the control unit which controls the displacement
unit to provide the movement by energy from an energy source and
based on the sensor signal. The cardiac assist device operation is
thus controlled in synchronicity with the heart action. The sensor
may be ECG electrodes or in addition or alternatively be based on
detecting one or more other physiological parameters related to the
cardiac activity, such as a blood pressure wave, acoustic heart
sounds, and/or blood flow patterns.
[0035] The energy source may be located in tissue under the skin,
adjacent to a vessel, such as a large vein. This allows for
convenient access to the displacement unit.
[0036] In another aspect of the invention, a kit is provided that
includes medical device of the above aspect of the invention and a
delivery system for the device. The delivery device may include an
introducer catheter with a valve, a guiding catheter, a guide wire
and at least one delivery catheter.
[0037] The device and kit may be used in medical procedures.
[0038] One medical procedure concerns delivering such a medical
device to enhance intra-cardiac blood circulation of a heart of a
patient by assisting left ventricular pump action. The method
includes providing a medical system including the medical device
and an energy source, and surgically and/or minimally invasively
delivering the medical system in the patient.
[0039] The method may include providing a delivery system, such as
of the aforementioned kit, for minimally invasively delivering the
medical device in the patient, and minimally invasively delivering
the displacement unit of the medical system in the patient by means
of the delivery system, delivering the energy source, and
connecting the energy source and the displacement unit.
[0040] The delivery system may include an introducer catheter with
a valve, a guiding catheter and a guide wire. The method then may
include introducing the introducer catheter at a puncture site into
the vascular system of the patient, inserting the guide wire into
the vascular system via the introducer catheter, navigating through
the vasculature and the heart to a desired site, inserting the
guiding catheter over the guide wire, withdrawing the guide wire,
through the guide catheter delivering a first anchor unit at a
mitral valve and delivering a second anchor unit at a distance from
the mitral valve.
[0041] The delivery system may include an introducer catheter with
a valve, a delivery catheter and a pushing unit, a guide wire and a
guiding catheter. The method then may include introducing the
introducer catheter at a puncture site into the vascular system of
the patient, inserting the guide wire into the vascular system via
the introducer catheter, navigating through the vasculature and the
heart to a delivery site, inserting the guide catheter over the
guide wire, providing an anchor unit at a distal end of the pushing
unit, introducing the distal end in front of the pushing unit into
the delivery catheter. The delivery catheter may have a smaller
outer diameter than an inner diameter of the guiding catheter, and
the method includes longitudinally moving the delivery catheter in
the guide catheter. Alternatively, the method includes retracting
the guide catheter, and longitudinally moving the delivery catheter
over the guide wire previously placed at the delivery site by means
of the guide catheter. Further, the method includes activating the
anchor unit by means of pushing the pushing unit forward while the
tip of the delivery catheter has contact with the surface of
delivery site, such as the left ventricle wall, and allowing anchor
elements of the anchor unit, such as hooks or blades to dig into
the tissue at the delivery site.
[0042] The pushing unit may be a catheter itself, small enough to
fit coaxially inside the outer delivery catheter. The pushing unit
may have a central lumen allowing the pulling and pushing unit to
pass there through all the way from outside of a patient and
through his or hers vascular system. The anchor element may have
hooks, and be retracted into the delivery catheter so that the
hooks of the anchor are having the tips facing forward towards the
catheter opening. Alternatively, or in addition, a separate lumen
may be attached, or integrated with, at least to part of the
delivery catheter. The guide wire lumen may also be inside the
delivery catheter.
[0043] The method may further include threading an extension unit
through the delivery system and releasing a mitral valve annulus
anchor by retracting the catheter of the delivery system from over
the mitral valve annulus anchor, and attaching the mitral valve
annulus anchor to the mitral valve annulus.
[0044] The method may include providing access to the vascular
system by puncturing a large vein, placing an introducer catheter
with a valve in the vein, through the introducer catheter advancing
a guide wire, and over the guide wire advancing a guide catheter to
the right atrium, obtaining access to the left atrium by
penetrating through an open foramen ovale or through the
inter-atrial wall and thereafter advancing the guiding catheter
into the left atrium, and advancing the guide catheter and the
guide wire into the left ventricle through the mitral valve to the
delivery site at the left ventricular wall, advancing a delivery
system for an anchor inside the guide catheter or over a guide wire
until its catheter opening has contact with the inner surface of
the left ventricular wall, advancing the pushing catheter and
pushing the anchor out of the catheter opening to dig into the
muscular tissue and pull the anchor inside the musculature, and
thereby creating a secure anchoring of a pulling and pushing unit,
and retracting the delivery catheter and pushing unit.
[0045] The method may include advancing a delivery system for a
mitral valve annulus anchor over the pulling and pushing unit until
the anchor and its arms are adjacent to the mitral valve annulus,
and when in position, retracting the catheter until outside of the
patient, allowing arms and their attachments hooks to attach to the
mitral valve annulus and dig into the tissue.
[0046] The method may further include adjusting the pushing and
pulling unit and the catheter in length and attaching to the remote
energy source.
[0047] The method may include positioning the remote energy source
in fatty tissue under the skin, adjacent to a vessel, such as a
large vein as the subclavian vein, and optionally attaching the
energy source to a bony structure, such as the clavicle.
[0048] Some methods may include providing surgical access to the
mitral valve, the mitral valve annulus and the left ventricle
including surgically opening the chest of a human being and
establishing extra corporeal circulation (ECC) or manipulating the
heart manually from the outside, while still pumping.
[0049] The method may include attaching a first anchor unit in the
musculature in the area of the inside left ventricular apex,
outside on the left ventricular apex, or in adjacent tissue,
attaching a second anchor unit to the mitral valve annulus, and
connecting the two anchors to each other by means of a connecting
unit that may shorten and increase the length between the anchors,
attaching the connecting unit to a remote energy source.
Alternatively, the method may include replacing the mitral valve by
an artificial valve unit serving as both the mitral valve and the
mitral annulus anchor.
[0050] In another aspect, a method is provided for permanently
enhancing left ventricular pump function of a heart of a patient,
the method comprising controlled assisted mitral valve movement
synchronized with a cardiac cycle of the heart.
[0051] The method may include providing a medical device adapted to
enhance intra-cardiac blood circulation of a heart of a patient by
assisting left ventricular pump action, the device having a
displacement unit, and controllably moving a mitral valve in a
mitral valve plane substantially along a long axis of a left
ventricle of the heart by the displacement unit, wherein the
controllably moving includes moving a mitral valve in the heart in
a reciprocating movement during systole towards an apex of the
heart and during diastole away from the apex for assisting the pump
action of the heart, and activating the medical device.
[0052] The method may include detecting the natural action of the
heart, such as by measuring an electrocardiogram, heart sounds, a
blood pressure wave or blood flow of the heart, and providing
energy for displacement of the mitral valve in synchrony with the
natural heart cycle, thereby enhancing the natural up and down
movement of a mitral valve during a heart cycle.
[0053] The method may include providing a mitral valve replacement
valve for the movement. The replacement valve may be mounted in a
housing, and moving the heart valve up and down in the housing
relative to a mitral valve annulus attachment.
[0054] Moreover, a system is provided for permanently enhancing
left ventricular pump function of a heart of a patient, the system
includes a displacement unit for controlled assisted mitral valve
movement synchronized with a cardiac cycle of the heart.
[0055] According to another aspect, a computer-readable medium
having embodied thereon a computer program is provided for
processing by a computer for permanently enhancing left ventricular
pump function of a heart of a patient, the computer program
comprising a code segment for synchronizing assisted mitral valve
movement in relation to the heart apex with a cardiac cycle of the
heart.
[0056] According to an aspect of the invention, there is provided a
kit for permanently enhancing the left ventricular function of a
heart. The kit includes a left ventricular enhancement or
augmentation system placed in the left ventricle, the left atrium
and the mitral valve, and in adjacent tissue able to move the
mitral valve plane, its annulus and leaflets along the direction of
the long axis of a left ventricle in synchrony with the heart
cycle, an energy source and a delivery system for carrying the
augmentation system to desired positions in the heart.
[0057] The kit may provide a convenient package to a surgeon who is
about to introduce an enhancement system into a patient. Thus the
kit provides both implants that may be used for permanently
treating the patient and a delivery system which may be used for
inserting the implants. The enhancing means may be pre-mounted in
the delivery system for storage, while the energy source may be
packaged separately for connection during surgery. The kit may
further have a guide wire for guiding insertion of the delivery
system to the desired positions through the vascular system of a
patient. The delivery system may also have a guiding catheter which
is arranged to be pushed over the guide wire to the desired
position. Also an introducing catheter for establishing access to
the vascular system by a percutaneous access may be part of the
kit. A valve that is prohibiting blood backflow but still allows a
guide wire or a guiding catheter to pass through is preferably
included in the introducing catheter.
[0058] According to a further aspect of the invention there is
provided a method for permanently treating failure of a left
ventricle in a patient. The method includes inserting a left
ventricular enhancement system into the left ventricle, the left
atrium and adjacent tissue and arranging an enhancement unit of the
enhancement system in desired positions such that the enhancement
unit may be connected to an energy source unit. The method includes
transfer of external energy to the enhancement unit in the left
ventricle, the left atrium and adjacent tissue in order to move the
mitral valve up and down along an axis from the left atrium towards
the left ventricular apex, i.e. the long axis, synchronized with
the natural heart cycle.
[0059] In embodiments, the method includes also insertion of an
energy source under the skin.
[0060] The method allows for connection of electrical cables or
device extensions for transferring power to the energy source in
such a way that the energy source may be located under the skin but
outside a vein.
[0061] Further, the method may involve transfer of electrical
energy through the skin either by cable or electro-magnetic in
order to store electrical energy in a battery under the skin.
[0062] In addition hereto the method may include the use of
computer chips and algorithms in order to detect the spontaneous
cardiac cycle and guide the enhancing system in accordance to the
heart cycle by means of detecting an electrocardiogram.
[0063] A preferable method of placing an energy source would be to
do this surgically through a small incision in the skin and make a
small pocket in the subcutaneous tissue under the skin. Part of the
method would be to use the same pocket to gain access to a vein by
means of puncturing the introducer catheter into the vein through
the pocket.
[0064] Still another part of the method would be to get access to
inside of the left heart by means of puncturing an artery in order
to place anchors.
[0065] Further it is part of some embodiments of the method to
attach an anchor to the inside or walls of the ventricles, the
mitral valve annulus or the atria by means of hooks. An alternative
method is to attach an anchor to the wall of the ventricles by
inserting it from the outside of the heart through a small surgical
incision.
[0066] Further, parts of the system may be implanted by surgical
means while the heart is stopped and its function temporarily is
provided by a heart- and lung-machine.
[0067] Further embodiments of the invention are defined in the
dependent claims, wherein features for the second and subsequent
aspects of the invention are as for the first aspect mutatis
mutandis.
[0068] It should be emphasized that the term "comprises/comprising"
when used in this specification is taken to specify the presence of
stated features, integers, steps or components but does not
preclude the presence or addition of one or more other features,
integers, steps, components or groups thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0069] These and other aspects, features and advantages of which
embodiments of the invention are capable of will be apparent and
elucidated from the following description of embodiments of the
present invention, reference being made to the accompanying
drawings.
[0070] FIG. 1 is a partly cross-sectional schematic illustration of
a human heart depicting structures that are involved.
[0071] FIG. 2 is a schematic illustration showing the level of the
mitral valve plane in relation to the left ventricular long
axis.
[0072] FIGS. 3 and 4 are schematic illustrations explaining the
normal movement of the mitral valve during a normal cardiac
cycle.
[0073] FIGS. 5-9 are schematic illustrations depicting how various
embodiments augment the mitral valve movement along the left
ventricular long axis.
[0074] FIGS. 10a and b are schematic illustrations that describe
different embodiments utilizing pulling and pushing forces in order
to augment the mitral valve movement.
[0075] FIGS. 11a-c are schematic illustrations that describe
different embodiments utilizing a linear actuator in order to
augment the mitral valve movement.
[0076] FIGS. 12a-b are schematic illustrations that depict an
embodiment using magnetic force in order to augment the mitral
valve movement.
[0077] FIGS. 13a-b are schematic illustrations which depict an
embodiment using rotational force in order to augment the mitral
valve movement.
[0078] FIGS. 14a-b are schematic illustrations that show a mitral
valve and the placement of a mitral valve annulus anchor.
[0079] FIG. 15 is a schematic illustration of an artificial heart
valve replacing the native mitral valve when integrated in an
embodiment of the system.
[0080] FIGS. 16a-c are schematic illustrations of an artificial
heart valve in a cage replacing the native heart valve when
integrated in an embodiment of the system.
[0081] FIGS. 17-19 are schematic illustrations of artificial heart
valves when integrated in further embodiments of the
innovation.
[0082] FIG. 20 is a schematic illustrations that depicts an
embodiment for complete catheter based implantation of the
system.
[0083] FIG. 21 is a schematic illustration that shows a remote
energy source for embodiments.
[0084] FIGS. 22-27 are schematic illustrations that show a delivery
system for complete catheter based insertion of the heart function
augmentation system.
[0085] FIGS. 28-30 are schematic illustrations of a method for
percutaneous complete catheter based placement of the
innovation.
[0086] FIG. 31 is a flowchart of the method.
DESCRIPTION OF EMBODIMENTS
[0087] Specific embodiments of the invention will now be described
with reference to the accompanying drawings. This invention may,
however, be embodied in many different forms and should not be
construed as limited to the embodiments set forth herein; rather,
these embodiments are provided so that this disclosure will be
thorough and complete, and will fully convey the scope of the
invention to those skilled in the art. The terminology used in the
detailed description of the embodiments illustrated in the
accompanying drawings is not intended to be limiting of the
invention. In the drawings, like numbers refer to like
elements.
[0088] The embodiments of the invention provide improved left
ventricular pump action by means of external power in order to be
able to move the native MV along the long axis of the left
ventricle (LV) towards and/or away from the heart apex, in
synchrony with the cardiac cycle. The here described permanent
implant will not take over or replace the remaining natural left
ventricular pump function, it rather augments the pump function. A
synchronized supported up and/or down movement is provided of the
mitral valve that works as a piston, when it is closed.
[0089] FIG. 1 depicts the anatomical structures of the heart 1, of
which at least some are involved in embodiments of the invention. 2
is the Superior Vena Cava (SVC), 4 is the right atrium (RA), 6 is
the Coronary Sinus (CS) ostium, 8 is the CS first part. 10 is the
Inferior Vena Cava (IVC), 12 is the Great Cardiac Vein (GCV) at the
level of the MV annulus 18. 14 is the Left Atrium cavity (LA), 16
is the LA wall, 18 is the mitral valve annulus, 19 the whole mitral
valve, 20 is the anterior leaflet and 21 is the posterior leaflet
of the mitral valve. 22 is the LV muscular wall, 24 are the
papillary muscles connected to the chordae, 26 is the apex of the
left ventricle. 28 is the aortic valve, 30 the aorta ascendens, 32
the inter-ventricular muscular septum, 34 the left ventricular
cavity and 36 the right ventricular cavity. 38 is the right
ventricular muscular wall and 40 is the tricuspid valve.
[0090] FIG. 2 shows the mitral valve plane 48 in relation to the
long axis 49 of the left ventricle. As can be seen, the LV long
axis 49 is close to perpendicular to the MV valve plane 48.
[0091] FIG. 3 is a schematic view of the natural, non-supported
movements in systole of the mitral valve plane 48 in relation to
the LV apex 26, the MV anterior 20 and posterior 21 leaflets, the
MV annulus 18, the aortic valve 28, the LA wall 16 and the LA
cavity 14 during a normal heart beat cycle. The large arrow (x)
shows the direction of the blood flow and the small arrow (y) the
direction of MV plane. In the cardiac cycle, the following moments
are shown in FIG. 3: a) immediately before systole, b) during
systole and c) at the end of systole. The piston movement (y) of
the mitral valve plane 48 during systole, pushing the blood out of
the aortic valve 28 can clearly be seen. In a diseased heart, this
natural systolic movement may be deteriorated. FIG. 4 is a
schematic view of the natural, non-supported movements in diastole
of the mitral valve plane 48 in relation to the LV apex 26, the MV
anterior 20, and posterior 21 leaflets, the MV annulus 18, the
aortic valve 28, the LA wall 16 and the LA cavity 14 during a
normal heart beat. The large arrow (x) shows the direction of the
blood flow and the small arrow (y) the direction of the MV plane
48. In the cardiac cycle, the following moments are shown in FIG.
4: a) early diastole, b) late diastole and c) end of diastole. In a
diseased heart, this natural diastolic return movement may be
deteriorated. At the end of diastole the mitral valve is now closed
and ready for the next movement downwards along the long axis of
the left chamber in the following systole.
[0092] In a diseased heart, for instance, the range of movement of
the MV plane may be reduced, e.g. due to heart muscle
insufficiencies. Further, other motion parameters, such as the
acceleration and/or maximum velocity component of the MV plane
movement may be reduced.
[0093] Embodiments as described below assist the remaining natural
movement in a diseased heart and thus may provide for an at least
partly restoration of the aforementioned motion parameters, such as
the range of movement and/or acceleration and/or maximum velocity
component of the MV plane movement either during systole, diastole
or both.
[0094] FIGS. 5 and 6 are schematic views of an embodiment of the
invention when inserted in the heart 1. FIG. 5 depicts, as in FIG.
3, the movements in systole of the mitral valve plane 48 in
relation to the LV apex 26, the MV anterior 20 and posterior 21
leaflets, the MV annulus 18, the aortic valve 28, the LA wall 16
and the LA cavity 14 during an augmented heart beat.
[0095] A pulling and pushing unit 54 applies a supporting force to
the MV. The pulling and pushing unit 54 forces the MV downwards
towards the LV apex during systole and away from the LV apex during
diastole. The supporting force is generated by means of external
power unit 84 and a power actuator 58 supplied to the pulling and
pushing unit 54. The pulling and pushing unit 54 is thereby
augmenting the natural force and extends the downwards movement of
the mitral valve 19. The movement of the MV plane 48 along the long
axis 49 is thus supported, augmenting the natural force of the
heart. The support makes the cardiac pumping action more effective,
i.e. cardiac output CO is enhanced. At the same time the cardiac
muscle is relieved. The large arrow (x) shows the direction of the
blood flow and the small arrow (y) the direction of MV plane.
[0096] The pulling and pushing unit 54 may in some embodiments
either actively push, pull, or perform both active push and active
pull action. The pulling and pushing unit 54 is then a pulling
and/or pushing unit. This selection of pulling and/or pushing is
done in dependence if assistance of the MV plane movement is to be
provided during systole or diastole or both. In case only one of
the pulling or pushing action is actively assisting the MV plane
movement, the other pushing or pulling action is made passively
(without assisting the natural movement) to return to the initial
position. For instance the MV plane may only be actively moved
towards the LV apex during systole (either by pulling or pushing),
and the return during diastolic filling may passively be made
(correspondingly by pushing or pulling) without assisting the
natural movement.
[0097] Embodiments where only the systole or diastole, or portions
thereof, are assisted, may provide for reduced energy consumption
of the medical assist device, leading to advantageously enhanced
battery life, etc.
[0098] The pulling and pushing unit 54 is at the proximal end
attached to a location of the mitral valve, for instance the MV
annulus. Attachment is made by means of a fixation unit 56. The
fixation unit 56 is for instance attached circular along the mitral
valve annulus 18, like a loop shaped annuloplasty ring. The other,
distal end of the pushing and pulling unit 54 is attached to an
energy converter unit 58 that transfers energy from the remote
energy source 84 (not shown) into a linear force. Energy from the
remote energy source 84 is in some embodiments provided as
electrical energy. A small linear actuator or an electrical motor
is suitable. In the cardiac cycle, the following moments are shown
in FIG. 5: a) immediately before systole, b) during systole and c)
end of systole.
[0099] FIG. 6 depicts, as in FIG. 4, the movements in diastole of
the mitral valve plane 48 in relation to the LV apex 26, the MV
anterior 20 and posterior 21 leaflets, the MV annulus 18, the
aortic valve 28, the LA wall 16 and the LA cavity 14 during an
augmented heart beat. The pulling and pushing unit 54 forces by
means of external power 84 (not shown) the mitral valve ring along
the long axis towards the left atrium, and is thereby augmenting
the natural cardiac upward force, extending and supporting the
upwards movement of the mitral valve 19 towards the LA. Thereby the
device is enhancing the diastolic filling of the LV before the next
heart beat. The large arrow (x) shows the direction of the blood
flow and the small arrow (y) the direction of MV plane. In the
cardiac cycle, the following moments are shown in FIG. 6: a) early
diastole, b) late diastole and c) end of diastole, the mitral valve
is now closed and ready for the next systolic downwards
movement.
[0100] A prototype of the invention was built, using a linear
accelerator and a computer. The computer allowed action in
synchrony with an electrocardiogram. The prototype was tested in an
animal experiment. The chest of a 60 kilogram pig was opened
between the ribs. A rod from the linear accelerator was attached to
the mitral valve annulus from the outside of the heart. The heart
function was depressed by means of drugs. After activating the
device an increase in arterial blood pressure and cardiac output
was observed.
[0101] FIGS. 7 and 8 are schematic views of another embodiment when
inserted in the heart 1. The device has two magnetic tissue
anchors, namely a first, proximal magnetic anchor 56 and a second,
distal magnetic anchor 60. The anchors 56, 60 are controllably and
selectively magnetic relative each other, allowing for a controlled
movement. The first anchor 56 is located at the MV, e.g. as a loop
shaped ring affixed to the MV annulus 18. The second anchor unit
60, is located in the LV cavity, e.g. affixed in its wall 22.
Alternatively, the second anchor 60 is attached to the LV outer
wall. The two anchors are magnets, preferably electromagnets, but
one or the other may also be a traditional permanent magnet. The
electromagnetic magnets are arranged to change polarity,
synchronized with the heart cycle in order to change between
pulling towards each other and/or pushing away from each other.
There are no physical connecting units between the anchor units,
which allows for an optimal movement along the LV long axis, which
may not entirely be perpendicular to the MV plane. When the
anchoring units have different polarity they move the two anchors
closer to each other and correspondingly, when the polarity is
equal, they move the two anchors away from each other. FIG. 7
depicts, as in FIG. 3, the movements in systole of the mitral valve
plane 48 in relation to the LV apex 26, the MV anterior 20 and
posterior 21 leaflets, the MV annulus 18, the aortic valve 28, the
LA wall 16 and the LA cavity 14 during an augmented heart beat. The
first magnetic anchor 56 (positive charged) and the second magnetic
anchor 60 (negative charged) attract each other and thus by means
of magnetic power the two anchors are attracted closer to each
other. This magnetic based supporting force is thereby augmenting
the natural cardiac muscle force and the downwards movement of the
mitral valve 19 is supported. The large arrow shows the direction
of the blood flow and the small arrow the direction of MV plane,
and the magnet 56. In the cardiac cycle, the following moments are
shown in FIG. 7: a) is immediately before systole, b) during
systole and c) end of systole.
[0102] FIG. 8 is a schematic view of the same embodiment as in FIG.
7 in diastole. FIG. 8 depicts, as in FIG. 4, the movements in
diastole of the mitral valve plane 48 in relation to the LV apex
26, the MV anterior 20 and posterior 21 leaflets, the MV annulus
18, the aortic valve 28, the LA wall 16 and the LA cavity 14 during
an augmented heart beat. The magnetic anchors 56 and 60 now have
equal polarity (here both negative) and push each other away. The
magnetic power thus forces the two anchors from each other, and is
thereby augmenting the natural cardiac force and supports the
upwards movement of the mitral valve 19, namely the MV plane 48
upwards along the long axis 49. The large arrow shows the direction
of the blood flow and the small arrow the direction of the MV plane
and the magnet 56. In the cardiac cycle, the following moments are
shown in FIG. 8: a) early diastole, b) late diastole and c) end of
diastole.
[0103] FIG. 9 shows alternative positioning of the second magnet
anchor 60. The second anchor 60 can be electromagnetic or classic
permanent magnetic. In embodiments where the second magnet 60 is
permanent magnetic, the first magnetic anchor 56 is an
electromagnetic with selectively activateable magnetic polarity.
The second anchor 60 can be placed in different positions in the
heart. However, positions outside the heart are also possible in
certain embodiments. Location 61 indicates a position where the
second anchor 60 is not attached to or in the heart. One such
position is in the pericardium. Another position is in the pleura
or under the skin. Possible alternative attachment sites include
the pericardium, or the diaphragm. The spine or the thoracic cage
(ribs and sternum) are also suitable sites for attachment of the
second anchor 60. Positions 62, 64, 66, 68 indicate positions for
the second magnet anchor 60 relative the heart. Position 62 is
located in the left ventricle and position 64 is located in the
right ventricle. Position 66 is located in the RA, preferably in
the so called atrial septum between the RA and the LA. One good
position is in the foramen ovale of the atrial septum where often
an opening is present to the LA. In this embodiment, the second
anchor unit may have the shape of a septal occluder and provide
both septal leakage occlusion and allows for support of the cardiac
function. Position 68 indicates a position in the LA, again a good
attachment site would be the atrial septum, another good position
in the LA would be the LA appendage (LAA, not shown). In this
embodiment, the second anchor unit may have the shape of an LAA
occluder and provides both LAA occlusion and allows for support of
the cardiac function. These are only examples and a person skilled
in the art may think of multiple variations that would work equally
well for the purpose.
[0104] Alternatively, or in addition, more than two second anchor
units may be provided accordingly. This may allow for smaller size
of each second anchor unit compared with a single second anchor
unit. Alternatively, or in addition, the first anchor unit may
comprise a plurality of sub units, allowing for similarly reduced
size and implanted mass of each sub unit compared to a single,
integral or monolithic, first anchor unit.
[0105] Electrical power for the mini motors, electromagnets or
linear actuators is in embodiments provided from the remote energy
source 84 by means of insulated cables 76.
[0106] Alternatively, or additionally, in other embodiments, such
as shown in FIGS. 10a and 10b the energy is transferred
mechanically from the remote energy source 84 through an extended
connecting unit 73. The connecting unit 73 may be arranged as a
Bowden cable type, having a movable inner wire surrounded by a
sheath 78. The connecting unit 73 extends all the way from a tissue
anchor 72, through the mitral valve attachment unit 56. The tissue
anchor 72 shown here is deployed in the LV muscle wall 22 near the
apex 26. The anchor has hooks 75 that dig into the tissue for a
strong attachment. One attractive option is to drop the anchor
prior to the mitral annulus attachment in order to let it grow into
the tissue and create a strong scar tissue before connection to the
energy source and starting the action of the device. A good
interval would be to allow ingrowth during 6-8 weeks prior to
starting cardiac assist operation of the device. The guiding sheath
78 is at its distal end fixated in the mitral annulus anchor 56 and
at its proximal end at the energy source 84. In this way the
following cardiac assist operation is provided. When proximally
pulling the connecting unit 73 (relative to the guiding sheath 78),
e.g. from an actuator at or inside the energy source, the distance
between the tissue anchor 72 and the MV fixation unit 56 will
shorten. When pushing the connecting unit 73 (relative to the
guiding sheath 78) proximately at the remote energy source, the
distance between the tissue anchor 72 and the MV fixation unit 56
increases. In this manner, cardiac assist is provided by supporting
the MV plane 48 movement along the long axis 49. FIG. 10a depicts
the situation when the extended connecting unit 73 is pushed
against the anchor 72. The mitral valve is then pushed upwards in
its diastolic position. FIG. 10b accordingly shows the opposite
situation in systole when the extended connected unit 73 is pulled
relatively to the sheath 78. The distal end of the sheath 78 is
affixed to the MV fixation unit 56. Thus, the mitral valve is being
pushed down in systole, towards the LV apex 26. The mitral valve is
thus brought closer to the apex 26, assisting the systolic natural
movement of the heart.
[0107] Turning to FIG. 11a, another embodiment is shown where the
external force is executed by means of an actuator. The electrical
power is supplied by the remote energy source 84 (not shown) by
means of a cable 76. Here the cable connects to the energy source
through the vascular system. The actuator may advantageously be
constructed as a mini linear actuator now available on the market.
The actuator may alternatively, or in addition, have a mini motor
integrated. MEMS (micro-electro-mechanical-systems) technology may
be utilized for constructing such a motor. Thus FIG. 11a depicts
the situation when the connecting unit 54 is pushed against the
mitral valve annulus attachment 56. The mitral valve will then be
pushed upwards in its diastolic position. In FIG. 11b accordingly,
the opposite situation is shown in systole, when the connecting
unit 54 is pulled towards the actuator 58. The mitral valve is thus
being pulled down in systole and the mitral valve is brought closer
to the apex 26. Here, an electrical cable 76 is connected to the
remote energy source 84 outside the vascular system.
[0108] In FIG. 11c it is illustrated that the axial actuator 58 not
necessarily needs to be arranged inside the LV cavity. As depicted
here, it may also be attached to the heart wall close to the apex
26.
[0109] FIGS. 12a-b show examples of configurations described in
FIGS. 7, 8 and 9, where electromagnets are used as tissue anchors
56. Further combinations of electromagnets and classical permanent
magnets will not be described in relation to separate figures as
such combinations will be apparent for the skilled person when
reading the examples given herein.
[0110] In FIG. 12a, one second anchor unit 60, e.g. a permanent
magnet, is located in the left ventricular wall close to the apex
26. The counter magnet unit, in form of a first anchor unit 56,
serves as an attachment to the mitral valve annulus 18. The first
anchor unit 56 is as well an electromagnet that may change polarity
according to the heart cycle. A known loop shaped annuloplasty
implant may be used with added magnetic functionality for the first
anchor unit 56. Such annuloplasty implants may be provided in an
annular shape, D-formed shape, open ring C-formed shape, etc.
Magnetic functionality may be added by a coil unit. The coil unit
may be integrated with the ring, or made easy to attach.
Alternatively, the coil unit may be provided as a flange unit
allowing for affixing the implant to the annulus tissue in a
convenient manner.
[0111] FIG. 12a depicts the situation in diastole, where both
magnetic units have the same polarity, here the poles are
illustrated positive. Thus the mitral valve is pushed away from the
LV apex, towards the LA. The mitral valve plane is re-positioned
upwardly along the LV long axis. Contrary to this, FIG. 12b shows
the situation in systole. The polarity of the magnet unit in the
mitral valve has changed polarity, here to negative, attracting the
positive charged magnet unit in the apex and pulling the mitral
valve against the apex.
[0112] Still another embodiment is now described with reference to
FIGS. 13a and 13b. Instead of pulling and pushing the extended
extension 73, as described above with reference to FIGS. 10a and
10b, the force is instead transferred by means of rotation of the
extension unit 73.
[0113] A connection unit 79 to the distal anchor 72 allows the
extension 73 to rotate and/or pivot freely relatively to the anchor
72. Such a pivoting connection unit may also be provided in other
embodiments having a physical connection between two anchor units,
in order to allow for an optimal movement along the LV long axis,
which may not entirely be perpendicular to the MV plane. The
connection unit 79 may be a swivel joint, e.g. a ball joint type of
bearing.
[0114] The extension unit 73 is provided with threaded windings 80
in the area of the mitral valve that correspond to mating threaded
windings in the mitral valve annulus attachment unit 56. By
rotating the extension unit 73 by means of a suitable actuator
powered by the remote energy source 84, the mitral valve is forced
upwards in diastole as depicted in FIG. 13a. Rotation may be made
in counter-clock direction for example. And correspondingly, while
rotating the extension unit in the other rotational direction, here
clockwise, as shown in FIG. 13b, the mitral valve is in turn forced
down along the long axis of the LV towards apex 26, as desired in
systole.
[0115] Movable units of embodiments, like the threaded windings 80,
the pivot joint, etc. may be suitably encapsulated to not be in
contact with blood or cardiac tissue to avoid any operational
complications. Alternatively, or in addition, moveable units of
embodiments may be covered with drugs that prohibit blood
components attachment that might compromise proper operation.
Examples of such drugs are Heparin or cytostatic drugs like
Sirolimus, Tacrolimus or any other drug that would avoid such blood
component attachment.
[0116] A normal mitral valve is shown in FIG. 14a. The anterior
leaflet of the valve 20 is much larger than the posterior leaflet
21. As a result thereof, the coaptation line 23 (line of contact)
where the two leaflets meet is not in the centre of the valve but
rather posterior. In FIG. 14b, a mitral valve annulus anchor 56 is
attached to the annulus by means of sutures 59. The anchor has more
or less the native form of the annulus circumference. The pushing
and pulling unit 54 and 73 are attached to the anchor by means of
an extension unit protruding from the anchor unit 56 towards the
coaptation line, like a rod 57. The rod 57 is in this figure shown
as being only attached to one position of the anchor 56. The rod 57
may also extend to the other side of the anchor, crossing the
entire MV diameter, and be attached here also, as indicated in
FIGS. 10, 11 and 13. In the illustrated embodiments the attachment
of the pulling and pushing unit 54 and 73 to the mitral valve
annulus anchor 56 is made excentric in order to be placed exactly
where the coaptation line 23 is. In this manner, the function of
the MV is substantially not affected. In other embodiments, the
pulling and pushing unit 54 and 73 may also be attached to the
anchor 56 itself and penetrate the valve at the annulus, behind
preferably the posterior leaflet of the valve.
[0117] The MV may be not working properly, e.g. due to insufficient
coaptation of the leaflets. In this case, the geometry of the MV
may be corrected in order to re-establish correct coaptation and
avoid regurgitation. In embodiments, the annulus anchor unit 56 may
be provided in form of a loop shaped annuloplasty implant
correcting the MV function at the same time as being part of the
cardiac assist system, which allows for a synergistic improvement
of heart function.
[0118] In situations where the mitral valve is so damaged due to
disease that it does not function well, it may be replaced by a
replacement artificial valve 100, such as shown in FIG. 15. The
native mitral valve has been cut away. Here is a biological
replacement valve depicted that is made of bovine pericardium or
pig valve tissue treated with Glutaraldehyde. The valve may also be
a mechanical artificial replacement heart valve, not shown here.
Leaflets 106 (three in the example shown in FIG. 16c) are mounted
in a frame or cage. The frame is preferably made of biocompatible
material, such as a suitable metal or plastic. The frame is on its
exterior affixed to the MV annulus. The frame may conveniently be
attached to a suture ring 102. The suture ring 102 is attached to
the mitral valve annulus instead of the anchor unit 56, and the
pulling and pushing unit 54 and 73 may be attached to the valve
frame instead of the anchor unit 56. Cardiac assist function is
then provided as in other embodiments by providing a synchronized
reciprocating movement of the MV plane of the replacement valve
along the LV long axis 49.
[0119] In still another embodiment, as illustrated in FIGS. 16 and
17, a replacement artificial valve is received in a housing in
which the replacement valve is arranged to move in the herein
described cardiac assist reciprocating movement along the LV long
axis. In the illustrated embodiment, a suture ring 102 is provided
to be attached to the mitral valve annulus. A cylinder 104 fits to
the size of the suture ring or a sealing ring of the valve allowing
the valve to move up and down inside the cylinder, thus acting as a
piston. Pushing and pulling unit 54, 73 and 78 may be attached to a
cage or struts 108 and to struts integrated in the valve 100. FIG.
17a depicts the valve in an up position during diastole and FIG.
17b in a down position during systole.
[0120] With reference to FIG. 18 a cardiac assist device having a
replacement valve is illustrated, where the driving force for the
reciprocating synchronized movement is electromagnetic. In the
illustrated situation the replacement valve is in the down position
in the cage 104. In the example, this is provided by means of two
magnets with identical polarity. Opposite polarities moves the
valve to the up position. One of the electromagnets may be replaced
by a permanent magnet.
[0121] In FIG. 19 it is illustrated that linear actuators or
electro-motors may also drive the valve up and down in the housing.
Such actuators may conveniently be integrated into the components
of the replacement valve embodiments. Preferably, the actuators are
integrated into the housing with counter elements in the
replacement valve.
[0122] As can be seen, the replacement valve embodiments do not
need a second anchor unit 72. These embodiments are thus
advantageous from that point of view. However, a remote second
anchor unit 72 may alternatively or in addition be provided in
certain embodiments, even with replacement valves, as the skilled
person will readily appreciate from the present disclosure.
[0123] A complete catheter based version of the cardiac assist
system is depicted in FIG. 20. As shown here, the anchor unit 56 is
provided in form of a foldable mitral valve annulus anchor 110 that
may be retracted inside a catheter while being guided through the
vasculature to the mitral valve and to the mitral valve annulus 18
and then unfolded and affixed into place. The foldable anchor may
have struts 112 that are attached to the mitral valve annulus, e.g.
by means of hooks 114. Such an anchor may also be in the shape of a
sling or a foldable ring, not shown. Further minimal invasive
embodiments will readily be available to the skilled person by
reading the present disclosure and are not depicted in detail,
except for further embodiments described below with reference to
FIGS. 22 to 30.
[0124] In some embodiments the return from the systolic down
position of the MV plane to the diastolic up position thereof may
be provided at least partly in a passive manner. This may be done
in several ways. For instance, the downward supporting action may
be stopped pre-mature at the end of systole when there is still
sufficient pressure in the LV to press the MV plane back towards
the diastole up position. When releasing the supporting force, or a
locked position at the end of the systole phase is unlocked, the MV
plane is released to move towards the diastole up position. The
timing may be cardiac cycle controlled, e.g. based on ECG and/or
pressure measurements, in accordance with the description below.
Alternatively, or in addition, a return spring element may be
provided to support this backwards movement. Alternatively, the
systolic position may be spring biased and only the return to the
diastolic position has to be made against this spring force by
suitable actuators or magnetic energy. Alternatively, or in
addition, the cardiac assist system may be provided as a bistable
system. Here, the diastolic up position and the systolic down
position of the MV plane may be provided as equilibrium states of
the system. Energy is provided from the external energy source to
initiate the system to move between the two stable positions. These
embodiments may be more energy efficient than others.
[0125] Permanent magnets in embodiments may be conventional iron
magnets. Alternatively, super magnets, like Neodymium rare earth
magnets may be used to improve efficiency and/or reduce size of the
units of the cardiac assist system, when comprising magnetic
elements.
[0126] Several actuating principles may be combined with each other
in certain embodiments, e.g. a linear actuator and magnetic
driving.
[0127] A remote energy source 84 is shown in FIG. 21. It has a
battery section 86 and a computing section 88 containing computer
algorithms and chips. The computer section 88 has receiving
electrodes or surfaces 92 connected, which are able to detect an
Electrocardiogram (ECG) signal. Based on the ECG signal, the
cardiac assist device operation is in embodiments controlled in
synchronicity with the heart action. Such synchronicity may in
addition or alternatively be established by means of detecting
other physiological parameters related to the cardiac activity.
Such parameters include a blood pressure wave or blood flow
patterns.
[0128] Alternatively, or in addition, the assisted mitral valve
movement may be controlled according to a set sequence of
reciprocating movements of the MV plane that mimics the natural
cardiac cycle to optimize the cardiac assist function. Frequency,
speed, and duration of different pause times of the reciprocating
movement may be set in the sequence to mimic a natural or desired
movement. The different parameters, such as pause time duration of
the movement, may vary over any time interval, and may be set to
vary according to a repeating program. The sequence may be
programmed into the computing section/control unit 88 which
controls the displacement unit. The displacement unit may then
provide the assisted movement according to the set sequence. Energy
from an energy source 84 may thus be controllably provided to the
displacement unit according to the set sequence for providing the
assisted movement.
[0129] Alternatively, or in addition, the medical device may be
incorporated into an artificial pacemaker system controlling or
assisting the natural cardiac muscle function. For instance the
assisted movement of the cardiac assist device may be controlled
from a processing unit of a pacemaker. The pacemaker including the
processing unit may be implanted in a patient. The pacemaker
triggers heart muscle activity in a per-se known manner, e.g. via
leads connected to the cardiac tissue for artificially triggering
the cardiac activity. Triggering of the assisted movement of the
cardiac assist device may be controlled may be based on the
electrical triggering of the cardiac activity by the artificial
pacemaker system, which is already synchronized with the cardiac
cycle. Preferably a time delay is provided from triggering
electrical triggering of the heart muscle activity to the
triggering/activation of the assisted movement of the cardiac
assist device during a heart cycle. The amount of the time delay
may be optimized, depending on the transfer time of electrically
triggering the heart muscle activity and the resulting pump
function of the heart caused by the controlled heart muscle
contraction.
[0130] The remote energy source 84 may have a mechanical section
90, where rotational or linear motion may be transferred to
extension unit 73. Rotational movement may be transferred directly
from an electrical motor, or geared down in revolutions by a
gear-box. Rotational energy from an electrical motor may be
converted to linear movement, enabling pulling and pushing force to
a wire connecting unit 73 that is extending all the way to the
distal anchor position. Alternatively, or in addition, the
mechanical section 90 may contain other actuators. For instance one
or more strong electromagnets may be provided in an actuator that
alternately are able to provide pulling and pushing force to a wire
connecting unit 73 that is extending all the way to the distal
anchor position. Further, the pulling and pushing force from the
remote energy source 84 may also be achieved by means of a linear
accelerator in the mechanical section 90. Alternatively, or in
addition, the mechanical section 90 contains an actuator providing
pulling and pushing force to a wire 73 that is extending all the
way to the distal anchor position by means of electrically
alternately cooling and warming a Nitinol actuator as commercially
available from MICA Motor Company, Modern Motion,
www.migamotors.com. Finally, in other embodiments, the remote
energy source is without a significant mechanical section, instead
computer chips are distributing electricity from the battery
according to the detected physiological parameter signal either to
electromagnets in one or more of the anchor units of the implanted
cardiac assist device or to mini-motors or linear actuators in a
heart chamber or on the heart surface as previously described, or
to actuators in the housing 104 in FIG. 19, etc.
[0131] The remote energy source may have a rechargeable battery
that e.g. is charged by means of a wire 94 penetrating the skin and
when charging the battery connected to a charging device externally
(not shown). Charging might also be done wireless through the skin,
e.g. by means of electromagnetic coils transferring energy
inductively. The skilled person in the art may alter and design
such charging according to specific requirements and available
actual technology.
[0132] In some particular embodiments, the remote energy source is
located in the fatty tissue under the skin, adjacent to a vessel,
preferably a large vein. This allows for convenient access to the
heart. Alternatively, the energy source may be attached to a bony
structure, such as the clavicle (not shown), in order to prohibit
dislocation of the same when delivering mechanical energy to the
cardiac assist device inside the heart. A pocket 95 in FIG. 28 in
the subcutaneous tissue may be created close to the actual vessel,
here the subclavian vein 3 in FIG. 28.
[0133] A delivery system and a method 800 for complete catheter
based insertion of the augmentation system are shown in the FIGS.
22-31.
[0134] The delivery system has an introducer catheter 120 with a
valve, a guiding catheter 122, a guide wire 124 and delivery
catheters 126 and 128. FIG. 22 shows the guiding catheter that has
a smaller outer diameter than the inner diameter of the introducer
catheter to fit inside. By means of the guiding catheter 122 and
the guide wire 124 one may navigate through the vasculature and the
heart to the desired site for delivering either a distal anchor 72
or a foldable mitral valve annulus anchor 110. All catheters
described in the system are made of synthetic material usually used
for medical catheters for interventional procedures in the vascular
system. Typical such materials are polyvinyl, polychloride,
polyethylene, polyurethane and other polymers.
[0135] A delivery system for the anchor unit 72 is shown in FIGS.
23-25. FIG. 23 shows a delivery system comprising an outer catheter
130 and a pushing unit 132. The pushing unit 132 is a catheter
itself, small enough to fit coaxially inside the outer delivery
catheter 130. The pushing unit 132 has a central lumen allowing the
pulling and pushing unit 73 to pass there through all the way from
outside of a patient and through his or hers vascular system.
[0136] The anchor unit 72 is illustrated in FIG. 23 being retracted
into the delivery catheter so that the hooks 75 of the anchor are
having the tips facing forward towards the catheter opening.
[0137] In FIG. 24 two alternative two methods are depicted for
navigating the delivery systems 126 and 128. In FIG. 24a, the
delivery catheter 130 has a smaller outer diameter than the inner
diameter of the guiding catheter 122 and may thus travel
longitudinally inside the latter. In FIG. 24b the delivering of the
anchor 72 is made without the guiding catheter 122 in place,
instead the delivery system 126 is running over a guide wire 124
previously placed at the delivery site by means of the guiding
catheter 122 that subsequently has been retrieved before device
insertion. A separate lumen 132 is attached, or integrated with, at
least to part of the delivery catheter 130, in other embodiments
the guide wire lumen may be inside the delivery catheter (not
shown).
[0138] In FIG. 25, delivery system 126 for the distal anchor is
shown being activated by means of pushing the pushing unit 132
forward while the tip of the delivery catheter has contact with the
inner surface of the left ventricle wall 26, allowing the hooks or
blades 75 to dig into the muscular tissue.
[0139] In FIG. 26, a delivery system 128 for the mitral valve
annulus anchor 110 is shown. Previously it has been described that
the mitral valve annulus anchor 110 is attached to the distal end
of catheter 78. The pulling and pushing unit 73 is attached
distally to the left ventricular wall by means of anchor 72 and
extend through delivery catheter 134 and through the catheter 78 to
outside of the patient and its vascular system. The extension 73 is
thread through the delivery system 134 by the operator after
deployment of distal anchor 72 as described. Releasing the mitral
valve annulus anchor 110 is done by retracting the catheter 134 of
the delivery system from over the anchor 110 that may attach to the
mitral valve annulus 18. FIG. 27 show both anchors 72 and 110
deployed. By pulling or pushing 72 relatively to 110 the mitral
valve may be moved up and down relatively to the apex of the heart
in synchrony with the cycle of the heart, wherein the movement
control is e.g. based on ECG.
[0140] A method for permanently augmenting the heart pumping
function by means of assisted mitral valve movement based on
complete catheter based technology is described with reference to
FIGS. 28-31. FIG. 28 shows the heart and the great vessels of a
human being, and FIG. 29 the right and left atrium, the atrial
septum 7, foramen ovale 5 and the mitral valve 19. Preferably
access to the vascular system is made in step 810 by puncturing a
large vein, shown here is the subclavian vein 3, but any other
large vein might be used, for instance the femoral vein in the
groin. An alternative, is a route through the arterial system for
access is depicted in FIG. 30, 39 is the iliac or femoral artery
and 37 the abdominal and thoracic aorta. Only the vein access will
be described here: An introducing large catheter 120 with a valve
(in order to prohibit blood spill) is placed in the vein. Through
the introducer catheter a guide wire 124 is advanced, and over the
guide wire a guide catheter is advanced in step 820 to the right
atrium 4. From here access is obtained to the left atrium 14 either
by penetrating an open foramen ovale (a native opening between the
two atria), or by means of pushing a needle (not shown) through the
inter-atrial wall 7 and thereafter advancing the guiding catheter
over the needle extension into the left atrium 14. Further, the
guide catheter 122 and the guide wire 124 are advanced into the
left ventricle through the mitral valve 19. Once the guide catheter
has contact with the left ventricular muscular wall at the desired
site, the delivery system 126 for the anchor 72 is advanced inside
the guide catheter or over a guide wire 124 in step 830 until its
catheter opening has contact with the inner surface of the left
ventricular wall 26. By means of advancing the pushing catheter
132, the tips of the hooks or blades 75 of anchor 72 will dig into
the muscular tissue and pull the anchor inside the musculature an
thereby create an secure anchoring of the pulling and pushing unit
73. The inventor has on several occasions placed such anchors into
the left ventricular musculature in animal experiences and observed
the hooks pull themselves into the tissue. In one embodiment of the
method, the anchor is allowed to heal into the musculature by scar
tissue over a period of preferably 6-12 weeks before the cardiac
assist system is activated. In animal experiments the inventor has
found such scar attachment stronger than the musculature itself,
and by pulling 1.5 to 2 kilogram force was necessary to pull the
anchor out, and then only together with the scar tissue.
[0141] Once the anchor has been deployed, catheters 130 and 132 are
retracted from the patient over the pulling and pushing unit 73.
Now the delivery system 128 for the mitral valve annulus anchor 110
is advanced over the pulling and pushing unit 73 in step 840 until
the anchor 110 and its arms 112 are adjacent to the mitral valve
annulus. When in position, the catheter 134 is retracted over the
catheter 78 until outside of the patient. The arms 112 and their
attachments hooks 114 are allowed to attach to the mitral valve
annulus and dig into the tissue in step 850. Again the same healing
in period of preferably 6-12 weeks before activation of the system
as already described may be applied. Other foldable slings or rings
may be used instead the arms described of anchor 110. A person
skilled in the art of catheter based technologies may use other
methods for attachments, still being within the scope of this
innovation. Once both anchors 72 and 110 are securely attached, the
pushing and pulling unit 73 and the catheter 78 are adjusted in
length and attached to the remote energy source 84 in step 860, and
the system may be activated in step 870. The remote energy source
has a unit to detect the natural action of a heart, e.g. based on
an electrocardiogram, a blood pressure wave or blood flow. The
remote energy source may thus provide energy for the distance
change between the two anchors in synchrony with the natural heart
cycle, thereby enhancing the natural up and down movement of a
mitral valve during a heart cycle.
[0142] A surgical method for permanently augmenting the heart
pumping function by means of assisted mitral valve movement based
on surgical technology is described with reference to FIGS. 10-19
and 21. Surgical access to the mitral valve, the mitral valve
annulus and the left ventricle is achieved by means of surgically
opening the chest of a human being and establishing extra corporeal
circulation (ECC) using a heart- and lung machine (HLM). One anchor
unit is attached in the area of the left ventricular apex, in the
musculature, on the left ventricular apex outside or in adjacent
tissue. A second anchor unit is attached to the mitral valve
annulus, preferably by means of suturing, but also clips or hooks
or other suitable methods for attachment may be used. The two
anchors are connected to each other by means of connecting unit
that may shorten and increase the length between the anchors. The
connecting unit is attached to a remote energy source. The remote
energy source has means to detect the natural action of a heart
e.g. in the form of an electrocardiogram, a blood pressure wave or
blood flow. The remote energy source may thus provide energy for
the distance change between the two anchors in synchrony with the
natural heart cycle, thereby enhancing the natural up and down
movement of a mitral valve during a heart cycle. Analog to the here
described surgical method, one magnetic anchor may be attached to
the mitral valve annulus in a similar way, while a second magnetic
anchor is attached to left ventricular musculature or elsewhere in
the heart, or adjacent to the heart as described above. The remote
energy source has means to detect the natural action of a heart
e.g. in the form of an electrocardiogram, a blood pressure wave or
blood flow. The remote energy source may thus provide electrical
energy through leads to the magnets in order to charge the magnets
and change the polarity of the magnets, thereby providing energy
for the distance change between the two magnetic anchors in
synchrony with the natural heart cycle, thereby enhancing the
natural up and down movement of a mitral valve towards and away
from the apex of the heart during a heart cycle.
[0143] In another embodiment of a surgical method, the native heart
valve is replaced by an artificial valve serving as both the mitral
valve and the mitral annulus anchor.
[0144] In still another surgical method for using the invention, an
artificial heart valve is mounted in a cage or housing, allowing
the heart valve to move up and down relatively to the mitral valve
annulus attachment by means of the remote energy source as
described.
[0145] Finally in a further embodiment of the surgical method,
access to the heart is achieved by surgically opening the chest.
Without the use of ECC the device insertion to the heart structures
is done by means of manipulating the heart manually from the
outside, while still pumping.
[0146] Concurrently filed patent application titled "A DEVICE, A
KIT AND A METHOD FOR HEART SUPPORT" claiming priority to U.S.
Provisional Application Ser. No. 61/317,619 filed Mar. 25, 2010,
and Swedish application Serial No. SE1050282-1 filed Mar. 25, 2010,
both entitled Device, a Kit and a Method for Heart Support, of the
same applicant as the present application, which are all
incorporated herein by reference in their entirety for all
purposes. This co-pending application discloses devices and methods
for permanently augmenting the pump function of the left heart. The
mitral valve plane is assisted in a movement along the left
ventricular long axis during each heart cycle. The very close
relationship between the coronary sinus and the mitral valve is
used by various embodiments of a medical device providing this
assisted movement. By means of catheter technique an implant is
inserted into the coronary sinus (CS), the device is augmenting the
up and down movement of the mitral valve and thereby increasing the
left ventricular diastolic filling and the piston effect of the
closed mitral valve when moving downwards for augmenting the left
ventricular pumping effect. Embodiments of the present disclosure
may be combined with embodiments of the co-pending application. For
instance an annuloplasty ring may be provided as a mitral valve
intra-atrial or intra-ventricular anchor unit with a CS anchor unit
or driving unit as described in the co-pending application. A
prosthetic artificial MV may be provided in combination with CS
anchor unit or driving unit, etc. The MV plane may advantageously
be well mechanically and stable be provided and moved more
efficiently by some of these combined embodiments.
[0147] The present invention has been described above with
reference to specific embodiments. However, other embodiments than
the above described are equally possible within the scope of the
invention. Different method steps than those described above,
performing the method by hardware or software, may be provided
within the scope of the invention. The different features and steps
of the invention may be combined in other combinations than those
described. The scope of the invention is only limited by the
appended patent claims.
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References