U.S. patent application number 10/989551 was filed with the patent office on 2005-06-16 for device, a kit and a method for treatment of disorders in the heart rhythm regulation system.
This patent application is currently assigned to Synergio AG. Invention is credited to Solem, Jan Otto.
Application Number | 20050131503 10/989551 |
Document ID | / |
Family ID | 29707923 |
Filed Date | 2005-06-16 |
United States Patent
Application |
20050131503 |
Kind Code |
A1 |
Solem, Jan Otto |
June 16, 2005 |
Device, a kit and a method for treatment of disorders in the heart
rhythm regulation system
Abstract
A tissue lesion creating device is structured and arranged to be
inserted through the vascular system into a body vessel adjacent
the heart and to be subsequently subjected to a change of shape in
order to penetrate into the heart tissue. The tissue lesion
creating device may thus be used for treating disorders to the
heart rhythm regulation system. A kit of devices provides a
plurality of devices for creating a lesion pattern for treating
such disorders.
Inventors: |
Solem, Jan Otto; (Stetten
(SH), CH) |
Correspondence
Address: |
BROWDY AND NEIMARK, P.L.L.C.
624 NINTH STREET, NW
SUITE 300
WASHINGTON
DC
20001-5303
US
|
Assignee: |
Synergio AG
Schaffhausen
CH
|
Family ID: |
29707923 |
Appl. No.: |
10/989551 |
Filed: |
November 17, 2004 |
Current U.S.
Class: |
607/96 |
Current CPC
Class: |
A61B 17/3205 20130101;
A61B 2017/00247 20130101; A61F 2002/249 20130101; A61B 2017/00243
20130101; A61B 17/32 20130101; A61F 2/91 20130101; A61B 2017/00292
20130101; A61B 2017/00867 20130101; A61B 2018/00392 20130101; A61F
2/2493 20130101; A61B 17/320016 20130101 |
Class at
Publication: |
607/096 |
International
Class: |
A61F 007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 17, 2003 |
SE |
0303017-8 |
Claims
1. A tissue lesion creating device for reducing undesired signal
transmission in the heart tissue, characterized in that the device
is structured and arranged to be inserted through the vascular
system into a body vessel adjacent the heart and to be subsequently
subjected to a change of shape in order to penetrate into said
heart tissue.
2. The tissue lesion creating device as claimed in claim 1, wherein
the device is structured and arranged to penetrate through a wall
of said vessel into said heart tissue.
3. The tissue lesion creating device as claimed in claim 1, wherein
the device has an initial elongate shape and wherein the device is
structured and arranged to change shape to expand its dimensions in
a direction transversally to its elongate direction.
4. The tissue lesion creating device as claimed in claim 1, wherein
the device comprises a shape memory material.
5. The tissue lesion creating device as claimed in claim 1, wherein
the device comprises a transversely expandable tubular part.
6. The tissue lesion creating device as claimed in claim 5, wherein
said tubular part of the device is funnel-shaped.
7. The tissue lesion creating device as claimed in claim 5, wherein
said tubular part comprises at least two axially separated tubular
portions, which are interconnected by a connecting member.
8. The tissue lesion creating device as claimed in claim 7, wherein
said tubular portions are transversely expandable to different
degrees.
9. The tissue lesion creating device as claimed in claim 5, wherein
an end of the tubular part forms an atrial end, said atrial end
being structured and arranged to change shape to extend radially
from the tubular part.
10. The tissue lesion creating device as claimed in claim 9,
wherein said atrial end comprises a plurality of arches overlapping
each other.
11. The tissue lesion creating device as claimed in claim 9,
wherein said atrial end when extending radially from the tubular
part forms an annular flange.
12. The tissue lesion creating device as claimed in claim 5,
wherein said device further comprises a cutting arm being
structured and arranged to initially extend axially from the
tubular part in order to be inserted into a heart atrium and said
cutting arm being structured and arranged to change shape to extend
radially from the tubular part.
13. The tissue lesion creating device as claimed in claim 12,
wherein the cutting arm has a form comprising at least one closed
loop.
14. The tissue lesion creating device as claimed in claim 13,
wherein the cutting arm has a form comprising a plurality of closed
loops arranged subsequently to each other in a longitudinal
direction of the cutting arm.
15. The tissue lesion creating device as claimed in claim 12,
wherein the device comprises at least two cutting arms, which are
structured and arranged to change shape to extend in different
radial directions from the tubular part.
16. The tissue lesion creating device as claimed in claim 5,
wherein said body vessel, which the tubular part is structured and
arranged to be inserted into, is the coronary sinus.
17. The tissue lesion creating device as claimed in claim 16,
wherein the tubular part, in a first state of the device before the
device is subjected to a change of shape, strives towards a shape
that is curved along its longitudinal direction to fit into the
coronary sinus.
18. The tissue lesion creating device as claimed in claim 16,
wherein the tubular part has a length corresponding to at least the
distance between the two lower pulmonary veins.
19. The tissue lesion creating device as claimed in claim 16,
wherein the cross-section of the tubular part is at least partly
elliptic.
20. The tissue lesion creating device as claimed in claim 16,
wherein said device further comprises a cutting arm being
structured and arranged to initially extend in an axial direction
of the tubular part in order to be inserted into the coronary sinus
and said cutting arm being structured and arranged to change shape
to extend radially from the tubular part.
21. The tissue lesion creating device as claimed in claim 1,
wherein an outside surface of the device is provided with sharp
edges.
22. The tissue lesion creating device as claimed in claim 1,
wherein an outside surface of the device is provided with
drugs.
23. The tissue lesion creating device as claimed in claim 22,
wherein said drugs include drug adapted to increase a cutting
effect through tissue.
24. The tissue lesion creating device as claimed in claim 23,
wherein said drug adapted to increase a cutting effect is any one
in the group of alcohol, glutaraldehyde, formaldehyde, and
proteolytic enzymes like collagenase.
25. The tissue lesion creating device as claimed in claim 22,
wherein said drugs include drug adapted to prohibit a thickening of
a wall of the body vessel in which the device is inserted.
26. The tissue lesion creating device as claimed in claim 25,
wherein said drug adapted to prohibit a thickening is any one in
the group of ciclosporin, taxiferol, rapamycin and tacrolimus.
27. The tissue lesion creating device as claimed in claim 22,
wherein said drugs include any one in the group of Endothelium
Growth Factor, Heparin, and amiodarone, sotalol or any other
antiarrythmic drug.
28. The tissue lesion creating device as claimed in claim 1,
wherein said device has a net-like shape formed of closed
loops.
29. The tissue lesion creating device as claimed in claim 1,
wherein the device is at least partly bioresorbable.
30. The tissue lesion creating device as claimed in claim 1,
wherein the device is made of a shape memory polymer.
31. The tissue lesion creating device as claimed in claim 1,
wherein the device is made of Nitinol.
32. The tissue lesion creating device as claimed in claim 1,
wherein the device is made of stainless steel, a titanium alloy or
a magnesium alloy.
33. A kit of shape-changing devices for treatment of disorders in
the heart rhythm regulation system, said kit comprising:
shape-changing devices, which each has a first and a second state,
wherein the device in the first state has such dimensions as to be
insertable to a desired position within the vascular system, and
wherein the device is capable of changing shape to the second state
when located at said desired position, the device in the second
state having a tubular part, which strives to a diameter that is
larger than the diameter of the vessel at the desired position,
whereby the device will become embedded into the tissue surrounding
the vessel at the desired position and destroy the tissue in order
to prevent it from transmitting electrical signals, wherein at
least one of the shape-changing devices is adapted to be inserted
to a desired position at the orifice of a pulmonary vein in the
heart, and at least one of the shape-changing devices is adapted to
be inserted to a desired position in the coronary sinus.
34. The kit as claimed in claim 33, wherein the shape-changing
device that is adapted to be inserted into the pulmonary vein
comprises an arm, which in the second state is arranged to contact
the shape-changing device in the coronary sinus.
35. The kit as claimed in claim 34, wherein said arm comprises a
trough in an area to come in contact with the shape-changing device
in the coronary sinus.
36. The kit as claimed in claim 33, wherein at least one of the
shape-changing devices is adapted to be inserted into the inferior
vena cava.
37. The kit as claimed in claim 36, wherein at least one of the
shape-changing devices is adapted to be inserted into the superior
vena cava.
38. The kit as claimed in claim 37, wherein at least one of the
shape-changing device that is adapted to be inserted into the
superior vena cava and the shape-changing device that is adapted to
be inserted into the inferior vena cava comprises an arm, which in
the second state is arranged to form a connection between these
shape-changing devices.
39. The kit as claimed in claim 33, wherein the kit comprises four
shape-changing devices, each being adapted to be inserted into a
respective pulmonary vein.
40. The kit as claimed in claim 39, wherein at least one of the
shape-changing devices being adapted to be inserted into a
pulmonary vein comprises an arm, which in the second state is
arranged to contact the shape-changing device in another pulmonary
vein.
41. The kit as claimed in claim 33, wherein at least one of the
shape-changing devices is adapted to be inserted into the left
atrial appendage.
42. The kit as claimed in claim 41, wherein the shape-changing
device that is adapted to be inserted into the left atrial
appendage comprises an arm, which in the second state is arranged
to contact the shape-changing device in a pulmonary vein.
43. The kit as claimed in claim 41, wherein the shape-changing
device that is adapted to be inserted into the left atrial
appendage comprises a film, which covers an end of the tubular
shape of the device in the second state.
44. The kit as claimed in claim 33, wherein at least one of the
shape-changing devices is adapted to be inserted into the right
atrial appendage.
45. A method for treatment of disorders in the heart rhythm
regulation system, said method comprising: inserting a tissue
lesion creating device through the vascular system to a desired
position in a body vessel, and providing a change of shape of the
tissue lesion creating device at said desired position to penetrate
heart tissue adjacent said body vessel.
46. The method according to claim 45, wherein said tissue lesion
creating device is inserted into a desired position in the coronary
sinus, in any of the pulmonary veins, in the superior vena cava, in
the inferior vena cava, or in the left or right atrial
appendage.
47. The method according to claim 46, further comprising inserting
another tissue lesion creating device to another of the desired
positions.
48. The method according to claim 47, further comprising inserting
a tissue lesion creating device into each of the desired
positions.
49. The method according to claim 45, further comprising
restraining the tissue lesion creating device in an insertion shape
during the inserting of the tissue lesion creating device.
50. The method according to claim 49, wherein the restraining
comprises keeping the tissue lesion creating device inside a
tube.
51. The method according to claim 49, wherein the restraining
comprises cooling the tissue lesion creating device.
52. The method according to claim 49, further comprising releasing
a restrain on the tissue lesion creating device when it has been
inserted into the desired position for allowing said change of the
shape of the tissue lesion creating device.
53. A medical device which is structured and arranged to be
inserted into a body vessel and subsequently change shape therein,
characterized in that the device is structured and arranged to
change shape to extend at least partly outside the perimeter or
orifice of an outer wall of said vessel.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to treatment of disorders in
the heart rhythm regulation system and, specifically, to a tissue
lesion creating device, a kit of shape-changing devices and a
method for treating such disorders.
BACKGROUND OF INVENTION
[0002] The circulation of blood in the body is controlled by the
pumping action of the heart. The heart expands and contracts by the
force of the heart muscle under impulses from the heart rhythm
regulation system. The heart rhythm regulation system transfers an
electrical signal for activating the heart muscle cells.
[0003] The normal conduction of electrical impulses through the
heart starts in the sinoatrial node, travels across the right
atrium, the atrioventricular node, the bundles of His and
thereafter spread across the ventricular muscle mass. Eventually
when the signal reaches the myocytes specialized in only
contraction, the muscle cell will contract and create the pumping
function of the heart (see FIG. 1).
[0004] The electrical impulses are transferred by specially adapted
cells. Such a cell will create and discharge a potential over the
cell membrane by pumping ions in and out of the cell. Adjacent
cells are joined end-to-end by intercalated disks. These disks are
cell membranes with a very low electrical impedance. An activation
of a potential in a cell will propagate to adjacent cells thanks to
the low impedance of the intercalated disks between the cells.
While being at the embryonic stage, all heart muscle cells, the
myocytes, have the ability to create and transfer electrical
signals. During evolution the myocytes specialize and only those
cells necessary for maintaining a stable heart-rate are keeping the
ability to create and send electrical impulses. For a more thorough
explanation of the propagation of electrical signals in the heart,
see e.g. Sandoe, E. and Sigurd, B., Arrhythmia, Diagnosis and
Management, A Clinical Electrocardiographic Guide, Fachmed A G,
1984.
[0005] The heart function will be impaired if there is a
disturbance on the normal conduction of the electrical impulses.
Atrial fibrillation (AF) is a condition of electrical disorder in
the heart rhythm regulation system. In this condition, premature
and fast signals irregularly initiating muscle contractions in the
atria as well as in the ventricles will be started in ectopic
sites, that is areas outside the sinoatrial node. These signals
will be transmitted erratically all over the heart. When more than
one such ectopic site starts to transmit, the situation becomes
totally chaotic, in contrast to the perfect regularity in a healthy
heart, where the rhythm is controlled from the sinoatrial node.
[0006] Atrial fibrillation is a very common disorder, thus 5% of
all patients that undergo heart surgery suffer from AF. 0.4-2% of a
population will suffer from AF, whereas 10% of the population over
the age of 65 suffers from AF. 160 000 new cases occur every year
in the US and the number of cases at present in the US is estimated
to be around 3 million persons. Thus, treatment of atrial
fibrillation is an important topic.
[0007] Typical sites for ectopic premature signals in AF may be
anywhere in the atria, in the pulmonary veins (PV), in the coronary
sinus (CS), in the superior vena cava (SVC) or in the inferior vena
cava (IVC). There are myocardial muscle sleeves present around the
orifices and inside the SVC, IVC, CS and the PVs. Especially around
the orifice of the left superior pulmonary vein (LSPV) such ectopic
sites are frequent, as well as at the orifice of the right superior
pulmonary vein (RSPV). In AF multiple small circles of a
transmitted electrical signal started in an ectopic site may
develop, creating re-entry of the signal in circles and the circle
areas will sustain themselves for long time. There may be only one
ectopic site sending out signals leading to atrial flutter, or
there may be multiple sites of excitation resulting in atrial
fibrillation. The conditions may be chronic or continuous since
they never stop. In other cases there may be periods of normal
regular sinus rhythm between arrhythmias. The condition will then
be described as intermittent.
[0008] In the chronic or continuous cases, the atrial musculature
undergoes an electrical remodelling so that the re-entrant circuits
sustain themselves continuously. The patient will feel discomfort
by the irregular heart rate, sometimes in form of cannon waves of
blood being pushed backwards in the venous system, when the atria
contract against a closed arterio-ventricle valve. The irregular
action of the atria creates standstill of blood in certain areas of
the heart, predominantly in the auricles of the left and right
atrium. Here, blood clots may develop. Such blood clots may in the
left side of the heart get loose and be taken by the blood stream
to the brain, where it creates disastrous damage in form of
cerebral stroke. AF is considered to be a major cause of stroke,
which is one of the biggest medical problems today.
[0009] Today, there are a few methods of treating the problems of
disorders to the heart rhythm regulation system. Numerous drugs
have been developed to treat AF, but the use of drugs is not
effective to a large part of the patients. Thus, there has also
been developed a number of surgical therapies.
[0010] Surgical therapy was introduced by Drs. Cox, Boineau and
others in the late 1980s. The principle for surgical treatment is
to cut all the way through the atrial wall by means of knife and
scissors and create a total separation of the tissue. Subsequently
the tissues are sewn together again to heal by fibrous tissue,
which does not have the ability to transmit myocardial electrical
signals. A pattern of cutting was created to prohibit the
propagation of impulses and thereby isolate the ectopic sites, and
thus maintain the heart in sinus rhythm. The rationale for this
treatment is understandable from the description above, explaining
that there must be a physical contact from myocyte to myocyte for a
transfer of information between them. By making a complete division
of tissue, a replacement by non-conductive tissue will prohibit
further ectopic sites to take over the stimulation. The ectopic
sites will thus be isolated and the impulses started in the ectopic
sites will therefore not propagate to other parts of the heart.
[0011] It is necessary to literally cut the atria and the SVC and
the IVC in strips. When the strips are sewn together they will give
the impression of a labyrinth guiding the impulse from the
sinoatrial node to the atrioventricular node, and the operation was
consequently given the name Maze. The cutting pattern is
illustrated in FIG. 2 and was originally presented in J L Cox, T E
Canavan, R B Schuessler, M E Cain, B D Lindsay, C Stone, P K Smith,
P B Corr, and J P Boineau, The surgical treatment of atrial
fibrillation. II. Intraoperative electrophysiologic mapping and
description of the electrophysiologic basis of atrial flutter and
atrial fibrillation, J Thorac Cardiovasc Surg, 1991 101: 406-426.
The operation has a long-time success of curing patients from AF in
90% of the patients. However, the Maze operation implicate that
many suture lines have to be made and requires that the cuts are
completely sealed, which is a demanding task for every surgeon that
tries the method. The operation is time consuming, especially the
time when the patients own circulation has to be stopped and
replaced by extracorporeal circulation by means of a heart-lung
machine. Thus mortality has been high and the really good results
remained in the hands of a few very trained and gifted
surgeons.
[0012] The original Maze operation has therefore been simplified by
eliminating the number of incisions to a minimum, still resulting
in a good result in most cases. The currently most commonly used
pattern of incisions is called Maze III (see FIG. 3).
[0013] Other methods of isolating the ectopic sites have also been
developed recently. In these methods, the actual cutting and sewing
of tissue has been replaced by methods for killing myocyte cells.
Thus, one may avoid separating the tissue, instead one destroy the
tissue by means of heat or cooling in the Maze pattern to create a
lesion through the heart wall. The damaged myocyte tissue can not
transfer signals any more and therefore the same result may be
achieved. Still the chest has to be opened, and the heart stopped
and opened. Further, the energy source has to be carefully
controlled to affect only tissue that is to be destroyed.
[0014] A large number of devices have now been developed using
various energy sources for destroying the myocyte tissue. Such
devices may use high radio frequency energy, as disclosed in e.g.
U.S. Pat. No. 5,938,660, or microwaves, ultrasound or laser energy.
Recently, devices have been developed for catheter-based delivery
of high radio frequency energy through the venous and or arterial
systems. However, this has so far had limited success due to
difficulties in navigation and application of energy and also late
PV stenosis has been reported. Further, devices using cooling of
tissue has used expanding argon gas or helium gas to create
temperatures of -160.degree. C. Using an instrument with a tip,
tissue can be frozen and destroyed.
SUMMARY OF THE INVENTION
[0015] It is an object of the invention to provide a new device and
method for treatment of disorders to the heart rhythm regulation
system. It is a further object of the invention to provide a device
and method that may be used without the need for open surgery or
stopping the heart.
[0016] According to an aspect of the invention, there is provided a
tissue lesion creating device for reducing undesired signal
transmission in heart tissue. The device is structured and arranged
to be inserted through the vascular system into a body vessel
adjacent the heart and to be subsequently subjected to a change of
shape in order to penetrate into said heart tissue.
[0017] Thanks to this aspect of the invention, the myocyte tissue
may be treated by simply inserting a device that is able to change
its shape into the vascular system of the heart. This may be done
through the vascular system, making the insertion only slightly
invasive. Thus, there is no need for stopping the heart or cutting
or treating of the myocyte tissue with advanced or demanding
methods. The invention provides an entirely new concept of treating
disorders in the heart rhythm regulation system and for cutting the
heart wall. The invention uses an inherent force in the device,
which alters the shape of the device and thereby affects the tissue
in the position where the device has been placed. The device is
structured and arranged to change its shape in such a way that it
will penetrate and cut through any tissue that is in the path of
its change of shape. Thus, by setting the shape of the device
properly and placing the device in a suitable position, the device
may by its own inherent force penetrate the tissue that needs
treatment. The tissue that is penetrated will be destroyed and
start a healing process within the body. The tissue will then be
replaced by fibrous tissue, which is not able to transmit
electrical signals. Thus, the signal transmission in the treated
heart tissue is reduced or blocked and the desired effect is
achieved. Therefore, such devices could be used for accomplishing
the creation of a cutting pattern for isolating ectopic sites
causing disturbances to the heart rhythm regulation system.
[0018] The device may be structured and arranged to penetrate
through a wall of the vessel into the heart tissue. In this way,
the device will only need to be inserted into a desired position
within the body vessel. Then, the device may itself penetrate the
body vessel wall in order to access the heart tissue to be treated
and thereafter the device may continue its change of shape to
penetrate the heart tissue. The device may change shape such that
it penetrates the body vessel wall in its entirety. Alternatively,
the device changes shape such that only a part of the device will
penetrate the vessel wall.
[0019] The device may have an initial elongate shape and the device
is structured and arranged to change shape to expand its dimensions
in a direction transversally to its elongate direction. Thanks to
the elongate shape, the device may interact with a substantial
portion of tissue, whereby the device will be stabilized and the
risk of it being transported by the blood flow away from its
desired position is reduced. Further, the device may readily be
inserted to the desired position through the vascular system, while
having a small cross-section, and then change its shape to increase
its dimension in the transversal direction. Thus, tissue outside
the vessel in the desired position may be treated.
[0020] The device may comprise a shape memory material. This is
suitable for providing the ability of the device to perform the
change of shape. The shape memory material may serve to maintain
the device in a first state while the device is being inserted, the
device in said first state being structured and arranged to be
inserted into a body vessel adjacent the heart through the vascular
system, and to transfer the device to a second state when the
device has been inserted to a desired position within the vessel,
the device in said second state being structured and arranged to
strive to obtain a shape that at least partly extends outside the
perimeter and the orifice of the vessel wall. Thus, the device
presents an initial shape in the first state allowing the device to
be inserted through the vascular system to a desired position in a
body vessel. Further, the device is self-transferable to a second
shape and, during the change of shape, the device will penetrate
heart tissue. The shape memory material will give the device a
strong inherent force, driving the device to perform the change of
shape. Meanwhile, as long as the shape memory material is not
activated it will retain its shape of the first state being suited
for insertion into a body vessel. Thus, by not activating or by
restraining the shape memory material until the device has been
inserted into the desired position, the device may readily be
inserted into the desired position through the vascular system.
Further, when the shape memory material is activated, the device
will strive towards a change of shape and will penetrate and
destroy tissue on its path to the new shape. The shape memory
material may easily be activated, e.g. by assuming a raised
temperature, which may be provided by the body temperature.
[0021] The device may comprise a transversely expandable tubular
part. The device may then be structured and arranged to be
subjected to a change of shape to expand the cross-section of the
tubular part such that the tubular part circumferentially
penetrates the vessel wall and thereafter penetrates the heart
tissue outside the vessel wall. If this device is inserted into an
artery or vein at its orifice into the heart, the circumferential
expansion of the device will treat the heart wall tissue around the
entire orifice. This is especially suitable, since the ectopic
sites often are located around and adjacent the orifices of the
pulmonary veins (PV). Further, the tubular form is suitable for
insertion into the vascular system.
[0022] In an embodiment, the tubular part of the device is
funnel-shaped. This implies that the cross-section of the tubular
part is larger at one end and smaller at the other end. This
feature of the device is also very suitable for devices that are
inserted at an orifice of a vessel into the heart, since only a
portion of the tubular part adjacent the heart wall near the
orifice needs to penetrate tissue outside the vessel. Thus, the end
that assumes a larger cross-section after the change of shape will
be inserted closest to the orifice to penetrate the heart wall
tissue around the orifice. Further, the other end of the tubular
part may have an expanded cross-section that is so small that it
stays in the inner layers of the vessel wall. This smaller end will
then serve only to keep the device in place.
[0023] The tubular part may comprise at least two axially separated
tubular portions, which are interconnected by a connecting member.
These tubular portions may then be structured and arranged to
change shape to expand to different diameters or be transversely
expandable to different degrees. This may be used for the same
purpose as the funnel-shape described above. Thus, at least one of
the tubular portions may be structured and arranged to change shape
to expand its diameter to correspond to the diameter of the vessel
where it is placed. In this way, this tubular portion will only
serve to keep the device in place. Another tubular portion may then
change shape to penetrate the heart tissue for the treatment
purposes. Further, the connecting member may be one or more bars or
wires connecting the tubular portions.
[0024] An end of the tubular part may form an atrial end. The
atrial end is structured and arranged to change shape to extend
radially from the tubular part. When radially extended the atrial
end will form a flange for fixing the device to the heart wall. A
device being inserted at the orifice of a vessel into the heart may
then comprise a flange, which may extend into the heart wall for
improving the fixation of the device and also contributing to the
treating of the heart wall tissue. In this way, the atrial end may
serve to fixate a device that is inserted into a vein leading to
the heart.
[0025] The atrial end may comprise a plurality of arches
overlapping each other. In this way, several different parts of the
atrial end contribute to the fixation of the device. Further, if
each arch changes shape to extend into the heart wall tissue, the
atrial end forms a dense pattern of treated heart wall tissue for
effectively isolating ectopic sites.
[0026] The atrial end may form an annular flange when extending
radially from the tubular part. Thus, the entire area around the
orifice of the vessel into the heart may be treated, and a stable
fixation may be accomplished.
[0027] In an embodiment, the device further comprises a cutting arm
being structured and arranged to initially extend axially from the
tubular part in order to be inserted into a heart atrium and said
cutting arm being structured and arranged to change shape to extend
radially from the tubular part. A cutting arm may create a lesion
along a cutting line in the heart wall. Thus, a specific cut may be
achieved and a specific portion of the heart wall may be treated.
By inserting the cutting arm into a heart atrium, the cutting arm
will initially be placed inside the heart wall, preferably in
contact with the heart wall. By further appropriately positioning
the tubular part, to which the cutting arm is connected, the
cutting arm could strive to assume a shape, where it extends
outside the heart wall. The cutting arm will then penetrate through
the heart wall and thereby create an elongate lesion.
[0028] The cutting arm may have a form comprising at least one
closed loop. The cutting arm will penetrate tissue forming a lesion
corresponding to the form of the cutting arm. As the cutting arm
comprises a closed loop, an islet of untreated tissue will be
formed inside the closed loop. Mainly, the cutting arm will create
a lesion, which will cause a line of scar tissue that represents an
effective block against propagation of undesired electrical
signals. Moreover, if there is an ectopic site present in the
islet, this ectopic site will be effectively isolated.
[0029] The cutting arm may have a form comprising a plurality of
closed loops arranged subsequently to each other in a longitudinal
direction of the cutting arm. This implies that a dense pattern of
treated tissue may be accomplished and several islets may be
formed, possibly isolating ectopic sites. Further, one or more
abutting islets create a line of scar tissue, representing an
effective block against propagation of undesired electrical
signals.
[0030] The device may comprise at least two cutting arms, which are
structured and arranged to change shape to extend in different
radial directions from the tubular part. This implies that lesions
along different cutting lines may be formed in order to obtain a
desired cutting pattern in the heart wall tissue.
[0031] The tubular part of the device may be structured and
arranged to be inserted into the coronary sinus (CS). The tubular
part may then, in a first state of the device before the device is
subjected to a change of shape, strive towards a shape that is
curved along its longitudinal direction to fit into the CS. Such a
device may be arranged to change shape to expand mainly at the
inside of the curve towards the heart wall. Hereby, a portion of
the heart wall along the CS may be treated. Further, the device
inserted into the CS may be arranged to form a support for a
cutting arm extending from a tubular part inserted into a PV, after
the cutting arm has performed its change of shape.
[0032] As used herein, the term "coronary sinus" implies not only
the portion of the vein at its opening to the right atrium, but
also the great cardiac vein extending from the right atrium for
draining blood from the heart tissue.
[0033] The tubular part to be inserted into the CS may have a
length corresponding to at least the distance between the two lower
PVs. This implies that a substantial portion of the heart wall may
be treated by the device inserted into the CS. Further, the CS may
then serve as a support for cutting arms extending from tubular
parts inserted in each of the lower PVs, respectively.
[0034] The cross-section of the tubular part to be inserted into
the CS may at least partly be elliptic. In this way, the expansion
mainly at the inside of the curve towards the heart wall may be
achieved. Of course, devices to be inserted in other vessels may
also present a tubular part having a cross-section that is at least
partly elliptic. Further, the cross-section of the tubular parts
may be varied infinitely to suit the area around the vessel to be
treated.
[0035] The cutting device to be inserted into the CS may also
comprise a cutting arm being structured and arranged to initially
extend in an axial direction of the tubular part in order to be
inserted into the CS and being structured and arranged to change
shape to extend radially from the tubular part. Thus, a specific
cut along a cutting line in the heart wall may be created from a
device inserted into the CS.
[0036] An outside surface of the device may be provided with sharp
edges. Thus, the ability of the device to penetrate through tissue
is increased, ensuring that the device will perform its change of
shape. All parts of a device, such as the tubular part, the atrial
end, and the cutting arm as described above, may be provided with
such sharp edges.
[0037] An outside surface of the device may also or alternatively
be provided with drugs. The drugs may be adapted to increase a
cutting effect through tissue. This will also increase the ability
of the device to penetrate through tissue and treat the tissue.
Also, the drugs may be adapted to prohibit a thickening of the wall
of the vessel, in which the device is inserted.
[0038] The drug adapted to increase a cutting effect may be e.g.
any one in the group of alcohol, glutaraldehyde, formaldehyde, and
proteolytic enzymes like collagenase. Further, any combination of
these drugs may be contemplated. These drugs will have a toxic
effect on tissue and thereby permit an easier penetration of the
device through tissue.
[0039] The drug adapted to prohibit a thickening of the vessel wall
may be e.g. any one in the group of ciclosporin, taxiferol,
rapamycin and tacrolimus. Further, any combination of these drugs
may be contemplated. The penetration of the device through tissue
in the body may cause a healing reaction in the body in the form of
a local proliferative reaction in the tissue. As a result of a
thickening of the vessel wall, the local proliferative reaction may
cause a stenosis, which is a very dangerous situation in the PV.
The drug adapted to prohibit a thickening of the vessel wall has an
anti-proliferative effect, i.e. it will prohibit a local
proliferative reaction and it will therefore prevent the thickening
of the vessel wall.
[0040] Moreover, the drugs may include any one in the group of
Endothelium Growth Factor, Heparin, amiodarone and sotalol.
Endothelium Growth Factor and Heparin are drugs preventing
thrombosis and increasing in-growth of endothelium on the
endothelial surface of the vessel wall after penetration of the
cutting device. Amiodarone and sotalol are drugs designed to treat
arrhythmias. Also, other drugs with these or other effects may be
contemplated.
[0041] The device may have a net-like shape formed of closed loops.
The device will penetrate tissue forming a lesion corresponding to
the form of the device having penetrated the tissue. As the device
has a net-like shape, islets of untreated tissue will be formed
inside the closed loop of the net. If there is an ectopic site
present in an islet, this ectopic site will be isolated. This
ensures that tissue is treated in a dense pattern. Further, the
net-like nature of the device also facilitates the penetration of
the device through tissue compared to a device having a complete
surface.
[0042] The device may be at least partly bioresorbable. Thus, the
device may first be inserted to a desired position and change its
shape to penetrate and destroy tissue in order to treat disorders
to the heart rhythm regulation system. Thereafter, the desired
effect of the device has been achieved and there is no further need
for the device being maintained in the body. Thus, the device may
be designed in a bioresorbable material to thereafter be absorbed
and repelled by the body or at least certain parts located in
especially inconvenient places may be absorbed.
[0043] The device may be made of a shape memory polymer. The shape
memory polymer may provide an inherent force to accomplish the
change of shape, when the device has been inserted to a desired
position. Further, a shape memory polymer may be resorbed by the
body. Alternatively, the device may be made of Nitinol or any other
metal alloy, which also has a shape memory for providing the
inherent force to accomplish the change of shape. Examples of other
shape memory alloys that may be used are alloys made of
titanium-palladium-nickel, nickel-titanium-copper, gold-cadmium,
iron-zinc-copper-aluminium, titanium-niobium-aluminium,
uranium-niobium, hafnium-titanium-nickel, iron-manganese-silicon,
nickel-iron-zinc-alumini- um, copper-aluminium-iron,
titanium-niobium, zirconium-copper-zinc or
nickel-zirconium-titanium. The device may alternatively be formed
to exhibit an elasticity for providing the inherent force. Thus,
the metal alloy may be e.g. stainless steel, a titanium alloy or a
magnesium alloy. The metal alloy may also be designed to be
resorbed by the body. This is possible for e.g. magnesium
alloys.
[0044] According to another aspect of the invention, there is
provided a kit of shape-changing devices for treatment of disorders
in the heart rhythm regulation system. The kit comprises
shape-changing devices, which each has a first and a second state,
wherein the device in the first state has such dimensions as to be
insertable to a desired position within the vascular system, and
wherein the device is capable of changing shape to the second state
when located at said desired position. In the second state, the
device has a tubular part, which strives to a diameter that is
larger than the diameter of the vessel at the desired position,
whereby the device will become embedded into the tissue surrounding
the vessel at the desired position and destroy the tissue in order
to prevent it from transmitting electrical signals. At least one of
the shape-changing devices is adapted to be inserted to a desired
position at the orifice of a pulmonary vein in the heart and at
least one of the shape-changing devices is adapted to be inserted
to a desired position in the coronary sinus.
[0045] According to this aspect of the invention, a kit of
shape-changing devices that may penetrate heart tissue provides a
possibility of placing the devices properly in vessels adjacent the
heart in order to penetrate surrounding tissue and, thus, create
lesions for affecting the transmission of electrical signals in the
tissue. The kit may provide devices adapted to be inserted such
that a suitable pattern of lesions may be created through the heart
wall. The kit may comprise various numbers of shape-changing
devices depending on how severe the electrical disorder of the
patient is. In some cases, it may be sufficient to treat the PV and
the CS, since the disease often starts in or around the PV. The
shape-changing devices inserted into the PV and the CS may be
expanded in the patient to come in contact with each other. Then,
the expansion will be stopped. Further, this ensures that all
tissue between the PV and the CS has been cut completely through
and thus effectively the entire heart wall between the PV and the
CS has been cut through creating a lesion between the PV and the
CS, and lesions around the PV and the CS. Similar contacts between
other shape-changing devices in the kit may be established between
PVs and the superior vena cava (SVC) or inferior vena cava (IVC) or
between the IVC and the CS.
[0046] The shape-changing device adapted to be inserted into the CS
may extend along a substantial length of the CS in order to be able
to create an elongate lesion in the heart wall adjacent the CS.
[0047] The shape-changing device that is adapted to be inserted
into the PV may comprise an arm, which in the second state is
arranged to contact the shape-changing device in the CS. Thus, a
lesion may be created from the PV to the CS, when the arm changes
shape. Further, the contact between the arm and the device in the
CS fixates the position of the arm.
[0048] The arm may comprise a trough in an area to come in contact
with the shape-changing device in the CS. This implies that the arm
may extend past the CS to further create a lesion in the heart wall
from the CS towards the mitral valve.
[0049] At least one of the shape-changing devices in the kit may be
adapted to be inserted into the IVC. Also, at least one of the
shape-changing devices in the kit may be adapted to be inserted
into the SVC. Thus, the treated pattern may extend around the IVC
and the SVC as well.
[0050] Further, at least one of the shape-changing device that is
adapted to be inserted into the SVC and the shape-changing device
that is adapted to be inserted into the IVC may comprise an arm,
which in the second state is arranged to form a connection between
these shape-changing devices. Thus, a lesion in the heart wall
between the SVC and the IVC may be created.
[0051] The kit may comprise four shape-changing devices, each being
adapted to be inserted into a respective PV. These shape-changing
devices may treat the tissue around each PV. These areas are
typical locations for ectopic sites.
[0052] Further, at least one of the shape-changing devices being
adapted to be inserted into a PV may comprise an arm, which in the
second state is arranged to contact the shape-changing device in
another PV. Thus, a lesion between the PVs may be formed in order
to further isolate the ectopic sites and create a cutting pattern
that may effectively treat disorders to the heart rhythm regulation
system.
[0053] At least one of the shape-changing devices in the kit may be
adapted to be inserted into the left atrial appendage (LAA). This
shape-changing device may be used for isolating the LAA totally
from electrical contact with the other parts of the heart.
[0054] Further, the shape-changing device that is adapted to be
inserted into the LAA may comprise an arm, which in the second
state is arranged to contact the shape-changing device in a PV.
[0055] The shape-changing device that is adapted to be inserted
into the LAA may comprise a film, which covers an end of the
tubular shape of the device in the second state. Thus, the
shape-changing device may be inserted with the end of the tubular
shape of the device covering the connection between the LAA and the
rest of the left atrium of the heart. In this way, the LAA is
excluded from the blood circulating in the heart. Since the LAA is
not needed for a satisfactory function of the heart, this will not
affect the function of the heart. Further, an exclusion of the LAA
effectively prohibits thrombus migration from the LAA, which may
otherwise send embolies to the brain causing cerebral strokes.
[0056] At least one of the shape-changing devices in the kit may be
adapted to be inserted into the right atrial appendage.
[0057] According to a further aspect of the invention, there is
provided a method for treatment of disorders in the heart rhythm
regulation system. The method comprises inserting a tissue lesion
creating device through the vascular system to a desired position
in a body vessel, and providing a change of shape of the tissue
lesion creating device at said desired position to penetrate heart
tissue adjacent said body vessel.
[0058] According to this aspect of the invention, a method is
provided, whereby disorders to the heart rhythm regulation system
may be treated without the need for stopping the heart or
exceptional surgical skills for creating lesions in the heart wall.
By simply inserting a shape-changing device to a desired position
through the vascular system, the lesions through the heart wall may
be created by means of the change of shape of the devices. The
insertion of a shape-changing device may be accomplished by means
of a catheter according to conventional methods. Further, by
releasing the shape-changing device out of the catheter, it may
change its own shape without requiring further controlling by a
surgeon. The shape-changing devices may be designed beforehand to
create a desired pattern of lesions for isolating ectopic sites in
the heart wall. Thus, the surgeon need only insert the
shape-changing devices to their correct positions. This method is
only slightly invasive, since it is intended to be inserted just by
means of skin puncture, and requires no surgical skills.
[0059] The method may further comprise restraining the tissue
lesion creating device in an insertion shape during the inserting
of the tissue lesion creating device. Thus, it may be ensured that
the tissue lesion creating device maintains an insertion shape
until it has been positioned at the desired position.
[0060] The restraining of the tissue lesion creating device may
comprise keeping the tissue lesion creating device inside a tube.
The tube will then prohibit the tissue lesion creating device from
expanding.
[0061] The restraining of the tissue lesion creating device may
also or alternatively comprise cooling the tissue lesion creating
device. Thus, the temperature of the tissue lesion creating device
may be held below a transition temperature trigging a change of
shape of the tissue lesion creating device.
[0062] The method may further comprise releasing a restrain on the
tissue lesion creating device when it has been inserted into the
desired position for allowing said change of the shape of the
tissue lesion creating device. The restrain may be released by
withdrawing a tube holding the tissue lesion creating device in an
insertion shape or by suspending the cooling of the tissue lesion
creating device. This release may control the initiation of the
change of shape of the tissue lesion creating device.
[0063] According to a further aspect of the invention, there is
provided a medical device which is structured and arranged to be
inserted into a body vessel and subsequently change shape therein.
The medical device is structured and arranged to change shape to
extend at least partly outside the perimeter or orifice of an outer
wall of said vessel. This medical device may be used to penetrate
tissue outside the vessel and thereby e.g. destroy heart tissue for
creating a block against propagation of undesired electrical
signals in the heart.
BRIEF DESCRIPTION OF THE DRAWINGS
[0064] The invention will now be described in further detail by way
of example under reference to the accompanying drawings, on
which:
[0065] FIG. 1 is a schematic view of the transmission of electrical
signals in the heart;
[0066] FIG. 2 is a schematic view of a pattern of cutting tissue of
the heart wall according to the Maze-procedure for treating
disorders to the heart rhythm regulation system;
[0067] FIG. 3 is a schematic view of a simplified pattern according
to the Maze III-procedure, wherein the heart is seen from
behind;
[0068] FIGS. 4a-4c are perspective schematic views of a tissue
lesion creating device according to an embodiment of the invention,
wherein FIG. 4a shows the tissue lesion creating device in a first,
temporary shape, FIG. 4b shows the tissue lesion creating device in
a second, permanent shape, and FIG. 4c illustrates the tissue
lesion creating device having sharp edges;
[0069] FIGS. 5a-5b show the tissue lesion creating device of FIGS.
4a-4b inserted in a body vessel;
[0070] FIGS. 6-12 show different embodiments of the tissue lesion
creating device;
[0071] FIG. 13 shows a tissue lesion creating device comprising a
cutting arm according to an embodiment of the invention, the tissue
lesion creating device being shown inserted into a vessel with the
cutting arm extending into a heart atrium before the tissue lesion
creating device has started acting on the heart wall tissue;
[0072] FIG. 14 shows the tissue lesion creating device of FIG. 13
during the time when the cutting arm penetrates a heart wall and
the tissue lesion creating device penetrates tissue at the orifice
of a vessel;
[0073] FIG. 15a shows the tissue lesion creating device of FIG. 13
after the tissue lesion creating device has penetrated the heart
wall and the vessel wall at the orifice area and has completed a
change of shape;
[0074] FIG. 15b shows the tissue lesion creating device of FIG. 13
after the device has penetrated the heart wall and has completed a
change of shape similarly to FIG. 15a, but where the cutting arm of
the device abuts another tissue lesion creating device inserted
into another vessel;
[0075] FIG. 15c is a schematic view showing the tissue lesion
creating device of FIG. 13 after it has completed its change of
shape, wherein the tissue lesion creating device has been inserted
into the left superior pulmonary vein and the cutting arm is
extended to the left atrial appendage opening;
[0076] FIG. 15d is a perspective view with a section of the vessel
and the heart wall cut-off and shows the tissue lesion creating
device of FIG. 13 after the device has penetrated the heart wall
and has completed a change of shape similarly to FIG. 15a, but
where the tissue lesion creating device comprises an atrial end
instead of the cutting arm;
[0077] FIGS. 16-23 are schematic views of the heart showing tissue
lesion creating devices inserted into different blood vessels
adjacent the heart and illustrating cutting patterns achieved by
these tissue lesion creating devices, wherein FIGS. 16-17 and 22-23
show a cross-section that has been cut through the atria of the
heart and FIGS. 18-21 show the atria of the heart from the outside
of the heart seen from behind;
[0078] FIGS. 24a-24b shows a cross-section of the left atrial
appendage and a tissue lesion creating device inserted into the
left atrial appendage, wherein FIG. 24a shows the tissue lesion
creating device before a change of shape has started and FIG. 24b
shows the tissue lesion creating device after the change of
shape;
[0079] FIGS. 25-26 illustrate tissue lesion creating devices
inserted into the left atrial appendage and the right atrial
appendage, the figures showing a cross-section that has been cut
through the atria of the heart;
[0080] FIGS. 27-29 illustrate three different embodiments of
accessing the vascular system;
[0081] FIG. 30 illustrates a guide wire being inserted into the
coronary sinus;
[0082] FIG. 31 illustrates a guide wire being inserted into the
coronary sinus and a guide catheter being inserted with its tip at
the orifice of the coronary sinus;
[0083] FIG. 32 is a view similar to FIG. 31 showing a first tissue
lesion creating device being inserted into the coronary sinus;
[0084] FIGS. 33 and 34 illustrate a guide wire having been inserted
into the left atrium;
[0085] FIGS. 35-37 illustrate the carrying and deployment of a
tissue lesion creating device by means of a delivery catheter;
[0086] FIGS. 38-40 illustrate the deployment of a tissue lesion
creating device in the left superior pulmonary vein; and
[0087] FIGS. 41-44 illustrate the insertion of a tissue lesion
creating device into the inferior and superior vena cava.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
[0088] Referring now to FIGS. 1-3, the problems of disorders to the
heart rhythm regulation system and the leading current method of
treating these problems will be described. In FIG. 1, a heart 2 is
shown and the controlling of the heart rhythm is indicated. The
heart rhythm is normally controlled from the sinoatrial node 4. The
sinoatrial node 4 transmits electrical signals which are propagated
through the heart wall by means of special cells forming an
electrical pathway. The electrical signals following the electrical
pathway will coordinate the heart muscle cells for almost
simultaneous and coordinated contraction of the cells in a heart
atrium and heart ventricle. The normal conduction of electrical
impulses through the heart starts in the sinoatrial node 4, travels
across the right atrium, the atrioventricular node 5, the bundles
of His 6 and thereafter spread across the ventricular muscle mass.
In a disordered situation, electrical signals are started in heart
cells outside the sinoatrial node 4, in so called ectopic sites.
These electrical signals will disturb the coordination of the heart
muscle cells. If several ectopic sites are present, the signal
transmission becomes chaotic. This will be the cause of arrhythmic
diseases, such as atrial fibrillation and atrial flutter.
[0089] An existing method for treating these diseases is based on
isolating the ectopic sites in order to prevent the electrical
signals started in these ectopic sites to propagate in the heart
wall. Thus, the heart wall is cut completely through for
interrupting the coupling between cells that transmit erratic
electrical signals. The thus created lesion will be healed with
fibrous tissue, which is unable to transmit electrical signals.
Thus, the path of the electrical signals is blocked by this lesion.
However, since the location of the ectopic sites may not always be
known and may be difficult to determine or since there might be
multiple ectopic sites, a special cutting pattern has been
developed, which will effectively isolate ectopic sites. Thus, the
same pattern may always be used regardless of the specific
locations of the ectopic sites in each individual case. The
procedure is called the "Maze"-procedure in view of the complicated
cutting pattern. In FIG. 2, the Maze-pattern is illustrated.
[0090] However, as is evident from FIG. 2, the cutting pattern is
extensive and complex and requires a difficult surgery. Thus, the
Maze-pattern has been evolved in order to minimize the required
cuttings and simplify the pattern as much as possible. Currently, a
Maze III-pattern is used, as shown in FIG. 3. This pattern is not
as complicated, but would still effectively isolate the ectopic
sites in most cases. The Maze III-pattern comprises a cut 8 around
the left superior pulmonary vein (LSPV) and the left inferior
pulmonary vein (LIPV) and a corresponding cut 10 around the right
superior pulmonary vein (RSPV) and the right inferior pulmonary
vein (RSPV); a cut 12 connecting the two cuts 8 and 10 around the
pulmonary veins (PV); a cut 14 from this connecting cut to the
coronary sinus (CS); a cut 16 from the left PVs to the left atrial
appendage; a cut 18 from the inferior vena cava (IVC) to the
superior vena cava (SVC); a cut 20 connecting the cut 10 around the
right PVs and the cut 18 between the IVC and the SVC; a cut 22 from
the cut 18 between the IVC and the SVC along the right lateral
atrium wall; and a cut 24 isolating the right atrial appendage.
Thus, a pattern, which is less complex and which effectively
isolates the ectopic sites, has been established. In some cases,
all cuts may not be needed. For example, the occurrence of ectopic
sites often starts around the orifices of the PVs and, therefore,
it may be sufficient to make the cuts 8, 10 around the PVs.
Further, as indicated with the lines 8' and 10', the cuts around
the PVs may be done along each PV orifice instead of in pairs.
[0091] According to the invention, there is provided a possibility
of cutting through the heart wall in a new manner. Thus, a similar
pattern to the Maze III-pattern should also be achieved according
to this new manner. However, as mentioned above, it may not in all
cases be required that all cuts of the Maze III-pattern are
made.
[0092] Referring now to FIGS. 4-5, a heart wall tissue lesion
creating device 26 according to an embodiment of the invention will
be described and the new manner of performing the cuts through the
heart wall will be explained. The heart wall tissue lesion creating
device 26 (hereinafter called cutting device) is shown in FIG. 4a
in a first state, in which the cutting device 26 is tubular and has
a first diameter d. The cutting device 26 is shown in FIG. 4b in a
second state, in which the cutting device 26 is tubular and has a
second diameter D, which is larger than the first diameter d. The
cutting device 26 is formed of a shape memory material, which has
the ability of memorizing a permanent shape that may significantly
differ from a temporary shape. The shape memory material will
transfer from its temporary to its memorized, permanent shape as a
response to a suitable stimulus. The stimulus may be exposure to a
raised temperature, such as a temperature above e.g. 30.degree. C.
that may be caused by the body temperature. The stimulus may
suitably be combined with the release of a restraining means, which
may keep the shape memory material from assuming its permanent
shape.
[0093] The shape memory material allows designing a cutting device
26 that may be contracted into a small, temporary shape before
insertion into a patient. Thus, the cutting device 26 may be
inserted in this temporary shape to the heart of a patient through
the vascular system. The temporary shape of the cutting device 26
is also flexible, whereby guiding the cutting device 26 through the
vascular system is facilitated. This insertion of the cutting
device 26 may be performed with well-known percutaneous catheter
techniques. This is an unaggressive procedure and may be performed
on a beating heart. Thus, the cutting device 26 may readily be
positioned at a desired position within the vascular system
adjacent heart wall tissue to be treated. The cutting device 26 may
then be allowed to transfer to its memorized, permanent shape when
inserted to the desired position in a blood vessel.
[0094] As shown in FIG. 5a, the cutting device 26 is inserted in
its temporary shape in a desired position within a blood vessel 28.
As a response to a stimulus, e.g. the body temperature, the cutting
device 26 will then strive towards changing its shape and obtaining
the permanent shape. The memorized, permanent shape of the cutting
device 26 will not fit into the blood vessel 28, whereby the
cutting device 26 will force itself through surrounding tissue for
obtaining the permanent shape, as shown in FIG. 5b. In this way,
the cutting device 26 will first penetrate the vessel wall and
thereafter tissue surrounding the blood vessel 28. Tissue cells
that are penetrated will be killed, which will start a healing
reaction in the body. Where the cutting device 26 is placed in a
desired position to change shape through heart wall tissue, cells
that are able to transmit electrical signals may thus be killed.
The healing process will not restore the ability to transmit
electrical signals and, therefore, the cutting device 26 will
reduce the ability of transmitting electrical signals through the
heart wall. By placing several cutting devices intelligently and
designing the permanent shape of the cutting devices 26
accordingly, the cutting devices 26 may penetrate heart wall tissue
to create a pattern of cuts corresponding to the Maze
III-pattern.
[0095] An example of a shape memory material is Nitinol, which is
an alloy composed of nickel (54-60%) and titanium. Small traces of
chrome, cobalt, magnesium and iron may also be present. This alloy
uses a martensitic phase transition for recovering the permanent
shape. Shape memory materials may also be formed of shape memory
polymers, wherein the shape-memory effect is based on a glass
transition or a melting point. Such shape memory polymers may be
produced by forming polymers of materials or combinations of
materials having suitable properties. For example, a shape memory
polymer may be created of oligo(e-caprolactone) dimethacrylate
combined with n-butyl acrylate. Also, biodegradable or
bioresorbable materials may be used for forming these shape memory
polymers. In this way, the cutting device 26 may be designed such
that it will be degraded or absorbed by the body after it has
performed its change of shape. For example, a polylactic acid
polymer and/or a polyglycolic acid polymer, poly (e-caprolactone)
or polydioxanone may be used for forming a shape memory polymer
that is biodegradable. A special feature of the resorbable shape
memory polymers is that these will disappear from the tissue after
having had its function, limiting potential negative effects of
otherwise remaining polymer or Nitinol materials, such as
perforations and damage to other adjacent tissues, like lungs,
oesophagus and great vessels like the aorta.
[0096] The cutting device 26 may alternatively be formed to exhibit
an elasticity such that it has a strive towards its permanent
shape. This may be accomplished by forming the cutting device 26 to
a spiral-shape in e.g. stainless steel or a magnesium alloy which
is biodegradable.
[0097] The cutting device 26 may be tubular in both its temporary
shape and its permanent shape, as shown in FIGS. 4-5. However, the
shape memory may be used for bringing the cutting device 26 between
any shapes. Some examples of shapes that are at least not entirely
tubular will be given below. The shape of the cutting device 26 in
its first state is preferably compact to facilitate insertion of
the cutting device 26 through the vascular system. Thus, a tubular
shape is suitable, but other shapes may be conceivable. Further,
the shape of the cutting device 26 in its second state is designed
such that the change of shape will provide penetration of specific
heart tissue in order to block propagation of undesired electrical
signals. Also, the shape of the cutting device 26 in its second
state may be adjusted for fixing the cutting device 26 to its
desired position within the body.
[0098] The cutting device 26 may be constructed of a net; i.e. its
shape may comprise meshes or loops. This implies that a solid
surface need not penetrate tissue, whereby the penetration through
tissue and the forming of different shapes of the cutting device 26
will be facilitated.
[0099] The edges of the cutting device 26 facing the tissue to be
penetrated may be made especially sharp to increase its
effectiveness, as illustrated in FIG. 4c. Another feature is to
cover the surface towards the tissue to be penetrated with drugs
that increase the cutting effect or prohibit the thickening of the
wall of the vessel in which the device is inserted. Examples of
such drugs are ciclosporin, taxiferol, rapamycin, tacrolimus,
alcohol, glutaraldehyde, formaldehyde, and proteolytic enzymes like
collagenase. Collagenase is effective in breaking down tissue and
especially fibrin tissue, which is otherwise difficult to
penetrate. Therefore, covering the surface of the cutting device 26
with collagenase would particularly speed up the process of
penetrating tissue. The drugs are attached to the surface of the
cutting device 26 according to well-known methods of attaching
drugs to medical devices. One such method is embedding drugs into
or under layers of polymers, which cover the surface. Of course,
other methods may be used. Similarly, drugs preventing thrombosis
and increasing in-growth of endothelium on the endothelial surface
after penetration of the cutting device 26 may be attached to the
cutting device 26. Such drugs would be e.g. Endothelium Growth
Factor, and Heparin. Also, other drugs designed to treat
arrhythmias may be attached to the cutting device surface. Such
drugs are e.g. amiodarone and sotalol.
[0100] Preferably, the inside of the cutting device 26 inserted
into a blood vessel will be in contact with the blood stream inside
the blood vessel. Such inside surface of the cutting device 26 may
as well be covered with antithrombotic drugs. Such drugs would be
e.g. Heparin, Klopidogrel, Enoxaparin, Ticlopidin, Abciximab, and
Tirofiban.
[0101] Another way to increase the effectiveness of the cutting
device 26 is to attach a metallic part of the cutting device 26 to
electrical currency, which would provide a heating of the cutting
device 26. Thereby, tissue may also be killed by this heating,
enhancing the effect of the cutting device 26. Further, the force
driving the change of shape will also be increased, speeding up the
shape change of the cutting device.
[0102] Referring now to FIGS. 6-12, cutting devices that are
specifically suited for insertion into specific blood vessels will
be described. All or some of these cutting devices may be delivered
in a kit to be used for treatment of a disorder of the heart rhythm
regulation system. Alternatively, the cutting devices may be
delivered separately. Then, the required cutting devices for an
operation may be assembled for each specific patient or for a
specific disease pattern. The cutting devices may also be provided
in different sizes to suit the size of the heart and the vessels of
the patient. Thus, a complete kit is assembled from devices
designed to fit to the anatomical conditions of the actual
treatment locations in order to achieve optimal results.
[0103] Referring now to FIG. 6, a first cutting device 30 adapted
to be inserted into the CS is shown. This first cutting device 30
has a tubular part 32, which is pre-bent to assume a curved shape
to fit to the curvature of the CS. Thus, the first cutting device
30 will assume a curved temporary shape within the CS. Further, the
cross-section of the first cutting device 30 is smaller in a distal
end 34 to be inserted furthest into the CS than at a proximal end
36 to be placed at the orifice of the CS. The cross-section of the
first cutting device 30 may be elliptic or circular or may vary
along the length of the cutting device 30. The first cutting device
30 may be designed to change shape such that the cross-section of
the first cutting device 30 is mainly expanded at the inside of the
curve towards the heart wall. Thus, the first cutting device 30
will penetrate the heart wall tissue adjacent the CS. Moreover, the
first cutting device 30 has a length of at least the distance
between the two inferior PVs. It can also be designed to cover the
distance from the orifice of the CS and past the LIPV. The first
cutting device 30 may serve as support for other cutting devices
inserted into other blood vessels adjacent the heart, as explained
in more detail later on. In this case, it may suffice that the
first cutting device 30 is fixated into the CS wall. There may also
not be any need for the first cutting device 30 penetrating heart
tissue itself, when treating the PV orifices solely. The first
cutting device 30 may also comprise one or more cutting arms (not
shown), which, in the temporary shape of the first cutting device
30, extend along the tubular part 32 or in an axial direction of
the tubular part 32. Further, the first cutting device 30 may be
arranged to change shape such that the one or more cutting arms
extend in a radial direction from the tubular part 32. Thus, during
the change of shape, the one or more cutting arms will penetrate
through heart tissue adjacent the CS.
[0104] Referring now to FIGS. 7a-b, a second cutting device 38
adapted to be inserted into the LIPV is shown. In FIG. 7a, the
second cutting device 38 is illustrated in a contracted, temporary
shape, and in FIG. 7b, the second cutting device 38 is illustrated
in an expanded state. This second cutting device 38 is adapted to
be inserted at the orifice of the LIPV into the heart. The second
cutting device 38 has a tubular part 40. As shown in FIGS. 7a-b,
the tubular part 40 may comprise two or more portions. A first
portion 42 of the tubular part 40 to be inserted closest to the
LIPV orifice is arranged to change shape to circumferentially
penetrate the LIPV wall and penetrate heart wall tissue around the
LIPV. Thus, an effective block against propagation of undesired
electrical signals is created around the orifice of the LIPV. A
second portion 44 of the tubular part 40 is arranged to change
shape to abut the vessel wall or only penetrate into the vessel
wall. Thus, this second portion 44 will only serve to stabilize the
second cutting device 38 in the axial direction and it may not be
needed. The first 42 and second portions 44 of the tubular part 40
are interconnected by a connecting member 46, in the form of bars
or wires. The first portion 42 may be funnel-shaped having a larger
diameter at the end closest to the orifice of the LIPV. The
funnel-shape will partly compensate for the increasing diameter of
the LIPV towards the orifice. However, the diameter of the
funnel-shaped first portion 42 may increase to a larger extent than
the LIPV towards the orifice, whereby the second cutting device 38
will penetrate deeper into the heart tissue at the orifice end.
Further, the smaller end of the funnel-shaped first portion 42 may
be arranged to merely penetrate into or abut the vessel wall for
stabilizing the second cutting device 38 in its axial direction.
The first portion 42 of the tubular part 40 may extend from the
orifice of the LIPV inside the heart to a position outside the
heart wall, whereby the smaller end of the funnel-shaped first
portion is arranged outside the heart wall. Thus, the first portion
42 may still penetrate through heart tissue throughout the entire
thickness of the heart wall, even though the smaller end of the
funnel-shaped first portion merely penetrates into or abuts the
vessel wall.
[0105] The tubular part 40 is typically arranged to change shape to
penetrate a circular area of tissue around and adjacent the LIPV.
However, the tubular part 40 may also be arranged to change shape
to expand to such a degree that it would come in contact with the
first cutting device 30 inserted into the CS, whereby the heart
tissue between the LIPV and the CS will be effectively treated.
Then, the first 30 and the second cutting devices 38 in contact
with each other will stabilize each other's positions.
[0106] The end of the tubular part 40 forms an atrial end 48, which
is arranged to be inserted extending into the heart atrium when the
second cutting device 38 is inserted into its desired position.
Thus, as shown in FIG. 7a, during insertion of the second cutting
device 38, the atrial end 48 will extend in an axial direction of
the tubular part 40. However, when the second cutting device 38
changes shape the atrial end 48 will be folded outwardly extending
in a radial direction to the tubular part 40, as shown in FIG. 7b.
The atrial end 48 will during its change of shape penetrate into
the heart wall for fixing the position of the second cutting device
38 and for forming a block against undesired electrical signals
around the orifice of the LIPV. This atrial end 48 may be formed
of, for instance, a multiple of arches overlapping each other. Each
such arch will penetrate through a piece of tissue adjacent the
LIPV orifice and leave a small islet of separated tissue, after
having penetrated through the tissue.
[0107] The second cutting device 38 may also comprise a cutting arm
50. The cutting arm 50 is attached to the end of the tubular part
40 to be inserted closest to the LIPV orifice. In the temporary
shape of the second cutting device 38, as shown in FIG. 7a, the
cutting arm 50 extends in an axial direction of the tubular part 40
for facilitating insertion of the second cutting device 38. In the
permanent shape of the second cutting device 38, the cutting arm 50
extends in a radial direction of the tubular part 40, as shown in
FIG. 7b. When the second cutting device 38 is placed in its desired
position, the cutting arm 50 will extend into the heart atrium.
Thus, during the change of shape of the second cutting device 38,
the cutting arm 50 will penetrate through the heart wall tissue to
assume a position extending radially from the tubular part 40. This
effect of the cutting arm 50 will be explained in more detail below
with reference to FIGS. 13-15. The cutting arm 50 will create a
line blocking propagation of undesired electrical signals in the
heart wall. Thus, the cutting arm 50 could make cutting lines for
forming the desired cutting pattern. The cutting arm 50 of the
second cutting device 38 may be arranged to make a cut from the
LIPV to the CS. Thus, the cutting arm 50 could come in contact with
the first cutting device 30 inserted into the CS, which would
fixate the position of the cutting arm 50. This cutting arm 50
could also comprise a trough 52 in the portion of the cutting arm
50 that will contact the first cutting device 38. This ensures that
the cutting arm 50 beyond the trough 52 may extend through the
heart wall from the CS to the mitral valve. The second cutting
device 38 may also have further cutting arms (not shown) to be
extended towards any of the other PVs.
[0108] The cutting arm is constructed of sequential loops in a
longitudinal direction of the arm. As these loops penetrate through
the heart wall tissue, closed loops of lesion lines will be formed,
creating islets of untreated tissue inside them. The lesion lines
will present a block of propagation of electrical signals.
[0109] Referring now to FIG. 8, a third cutting device 54 adapted
to be inserted into the RIPV is shown. This third cutting device 54
presents similar features as the second cutting device 38. Thus,
the third cutting device 54 also comprises a tubular part 56, which
also may consist of two or more tubular portions 58, 60, which are
interconnected by a connecting member 62. The tubular part 56 of
the third cutting device 54 presents similar features as the
tubular part 40 of the second cutting device 38. The third cutting
device 54 also comprises an atrial end 64, similar to the atrial
end 48 of the second cutting device 38. Moreover, the third cutting
device 54 also comprises a cutting arm 66, similar to the cutting
arm 50 of the second cutting device 38. This cutting arm 66 is
arranged to change shape in order to extend radially from the
tubular part 56 towards the CS and come in contact with the first
cutting device 30 inserted into the CS close to the orifice of the
CS. The cutting arm 66 of the third cutting device 54 is normally
shorter than the cutting arm 50 of the second cutting device 38
permitting adaptation to the different distance between the third
cutting device 54 and the CS. Further, the cutting arm 66 of the
third cutting device 54 need not have a trough, since, in this
case, there is no need of treating heart tissue beyond the CS. The
third cutting device 54 may also comprise other cutting arms (not
shown) extending towards any of the other PVs.
[0110] Referring now to FIG. 9, a fourth cutting device 68 adapted
to be inserted into the LSPV is shown. This fourth cutting device
68 presents similar features as the second and third cutting
devices 38, 54. Thus, the fourth cutting device 68 also comprises a
tubular part 70, which may consist of two or more tubular portions
72, 74, which are interconnected by a connecting member 76. The
tubular part 70 of the fourth cutting device 68 presents similar
features as the tubular part 40, 56 of the second and third cutting
devices 38, 54. The fourth cutting device 68 also comprises an
atrial end 78, similar to the atrial end 48, 64 of the second and
third cutting devices 38, 54. Moreover, the fourth cutting device
68 also comprises a cutting arm 80, similar to the cutting arm 66
of the third cutting device 54. This cutting arm 80 is arranged to
change shape in order to extend radially from the tubular part 70
towards the LIPV and come in contact with the second cutting device
38 inserted into the LIPV. The cutting arm 80 of the fourth cutting
device 68 is normally very short permitting adaptation to the short
distance between the LSPV and the LIPV, which is typically a few
millimeters to a centimeter. The fourth cutting device 68 may also
comprise another cutting arm (not shown), which after the change of
shape of the fourth cutting device 68 would extend towards the left
atrium appendage orifice.
[0111] Referring now to FIG. 10, a fifth cutting device 82 adapted
to be inserted into the RSPV is shown. This fifth cutting device 82
presents similar features as the second, third and fourth cutting
devices 38, 54, 68. Thus, the fifth cutting device 82 also
comprises a tubular part 84, which may consist of two or more
tubular portions 86, 88, which are interconnected by a connecting
member 90. The tubular part 84 of the fifth cutting device 82
presents similar features as the tubular part 40, 56, 70 of the
second, third and fourth cutting devices 38, 54, 68. The fifth
cutting device 82 also comprises an atrial end 92, similar to the
atrial end 48, 64, 78 of the second, third and fourth cutting
devices 38, 54, 68. However, the fifth cutting device 82 would
normally not comprise any cutting arm, since it would normally be
sufficient to penetrate the tissue around the RSPV. The fifth
cutting device 82 may anyhow comprise a cutting arm adapted to
extend towards any of the other PVs.
[0112] Referring now to FIG. 11, a sixth cutting device 94 adapted
to be inserted into the left atrial appendage (LAA) or the right
atrial appendage (RAA) is shown. The sixth cutting device 94
comprises a tubular part 96, which has an elliptic cross-section to
fit into the elliptic form of the orifice of the LAA. A sixth
cutting device 94 adapted to be inserted into the RAA will have a
tubular part 96 with a less elliptic cross-section to fit the
orifice of the RAA. The sixth cutting device 94 is adapted to be
inserted into the orifice of the LAA inside the left atrium or into
the orifice of the RAA inside the right atrium. The sixth cutting
device 94 will further change shape by expanding its tubular part
96 through the atrial wall at the orifice. Thus, the LAA or the RAA
will be completely cut off from electrical contact with the rest of
the heart tissue. The tubular part 96 of the sixth cutting device
94 may be quite short extending from the orifice of the atrial
appendage along its wall into the atrial appendage. Further, the
tubular part 96 may be funnel-shaped, whereby a portion of the
tubular part 96 may be designed to change shape in order to assume
a cross-section that will not penetrate through the entire heart
wall. This portion of the tubular part 96 may then serve to keep
the sixth cutting device 94 in place. Further, another portion of
the tubular part 96 will penetrate through the entire heart wall in
order to effectively electrically isolate the atrial appendage from
the rest of the heart. A sixth cutting device 94 adapted to be
inserted into the LAA may comprise a cutting arm (not shown), which
is adapted to change shape to penetrate through the heart tissue
extending from the LAA to a fourth cutting device 68 inserted into
the LSPV. Further, a sixth cutting device 94 adapted to be inserted
into the LAA may comprise a film 98 covering an end of the tubular
part 96 to be inserted closest to the orifice of the LAA. When the
tubular part 96 is expanded into the heart wall, the film 98 will
cover the orifice of the LAA, excluding the LAA from the blood
circulating through the heart, whereby a dislocation of thrombus
and clot formation in the LAA will be avoided.
[0113] Referring now to FIG. 12a, a seventh cutting device 100
adapted to be inserted into the IVC and the SVC is shown. The
seventh cutting device 100 comprises two pieces 102, 104, a first
piece 102 to be inserted into the SVC and a second piece 104 to be
inserted into the IVC. Each piece 102, 104 of the seventh cutting
device 100 comprises a tubular part 106, 108, which presents
similar features as the tubular part 40, 56, 70, 84 of the second,
third, fourth, and fifth cutting devices 38, 54, 68, 82. Each
tubular part 106, 108 may advantageously be funnel-shaped, wherein
an end having the largest cross-section is adapted to be inserted
closest to the orifice of the IVC or the SVC, respectively. The
seventh cutting device 100 further comprises a connecting cutting
arm 110. The seventh cutting device 100 is arranged to change shape
such that this connecting cutting arm 110 will extend between the
tubular part 106 of the first piece 102 inserted into the SVC and
the tubular part 108 of the second piece 104 inserted into the IVC.
This change of shape will cause the connecting cutting arm 110 to
penetrate through the lateral right atrium heart wall tissue
between the orifice of the SVC and the orifice of the IVC. The
connecting cutting arm 110 may be attached to any one of the first
and the second piece 102, 104 of the seventh cutting device 100,
and preferably the connecting cutting arm 110 is attached to both
the first and the second pieces 102, 104. If the connecting cutting
arm 110 is only attached to one of the first and second pieces 102,
104, it will connect the first and the second pieces 102, 104
together after the change of shape has occurred. The connecting
cutting arm 110 may comprise a branch 112, which, after the change
of shape of the seventh cutting device 100, will extend from a
point of the connecting cutting arm 110 laterally through the right
atrial wall, whereby this branch 112 will penetrate the right
lateral wall of the right atrium. As for the cutting arms, the
branch 112 may be constructed of one loop or several sequential
loops in a longitudinal direction of the branch 112. The seventh
cutting device 100 may comprise a further cutting arm (not shown),
which may be attached to the tubular part 108 of the second piece
104 that is inserted into the IVC. The seventh cutting device 100
is then arranged to change shape such that this further cutting arm
will extend from the tubular part 108 of the second piece 104
inserted into the IVC towards and into the orifice of the CS. This
change of shape will cause the further cutting arm to penetrate
through the heart wall tissue between the orifice of the IVC and
CS. This further cutting arm may alternatively be arranged as a
further branch of the connecting cutting arm 110. The seventh
cutting device 100 may, in a simple version for treating mild forms
of disorders to the heart rhythm regulation system, consist of only
the first piece 102 adapted to be inserted into the SVC, which
first piece 102 may or may not comprise a cutting arm. As shown in
FIG. 12b, the first and second pieces 102, 104 may also each
comprise an atrial end 103, 105, similar to the atrial end 48, 64,
78, 92 of the second, third, fourth, and fifth cutting devices 38,
54, 68, 82.
[0114] Referring now to FIGS. 13-15, the action of a cutting arm
will be explained in further detail. In FIG. 13, a cutting device
114 comprising a cutting arm 116 has been inserted into a blood
vessel at the orifice of the opening into the heart. The cutting
device 114 comprises a tubular part 118, which is inserted into the
blood vessel. The cutting arm 116 is attached to the tubular part
118 and extends into the heart. In FIG. 13, the cutting device 114
is shown in an intermediate shape, which it has during insertion of
the cutting device 114. The cutting device 114 has carried to the
illustrated position on a catheter 113a while being restrained by a
restraining sheath 113b. The cutting device 114 is shown when the
tubular part 118 has been released while the cutting arm 114 is
still restrained by the restraining sheath 113b. Thus, a change of
shape has not yet been fully commenced. In FIG. 14, the cutting
device 114 is shown during its action of changing its shape. Thus,
the cutting arm 116 is extending from the inside of the heart into
the heart wall tissue having penetrated heart tissue during the
shape-change. The cutting arm 116 will continue penetrating heart
tissue in order to obtain the permanent shape of the cutting device
114. In FIG. 15a, the cutting device 114 is shown after having
completed its change of shape. The tubular part 118 has now cut
through the vessel wall and penetrated heart tissue around the
vessel. Further, the cutting arm 116 is now completely outside the
heart. Thus, the cutting arm 116 has now penetrated the entire
heart wall and has therefore caused a lesion along a cutting line
from the orifice of the blood vessel wall through the selected
adjacent heart wall. The penetrated tissue is marked with shading
in FIG. 15a, as well as in FIGS. 15b-d. In FIG. 15b, the cutting
arm 116 of the cutting device 114 is shown abutting another cutting
device 120, which has been inserted into another blood vessel. In
this way, the cutting arm 116 has performed a lesion between the
two cutting devices, whereby an effective block against propagation
of undesired electrical signals has been created. The position of
the cutting arm 116 is also stabilized after the change of shape by
the cutting arm 116 resting on the other cutting device 120. In,
FIG. 15c, the cutting device 114 is shown inserted into the LSPV,
and the cutting arm 116 has been extended leaning into the orifice
of the LAA and thereby penetrating the atrial wall between the LAA
and the LSPV. In addition to the cutting of the cutting arm 116,
the tubular part 118 of the cutting device 114 inserted inside the
vessel has treated the vessel wall adjacent to the orifice, which
often contains ectopic sites. In FIG. 15d, the cutting device 114
is shown comprising an atrial end 121, which has penetrated the
tissue around the orifice of the blood vessel.
[0115] Referring now to FIGS. 16-26, there is shown cutting
patterns being obtained in a few different embodiments,
illustrating a few examples of sets of cutting devices being
inserted into blood vessels adjacent the heart and the treatment
obtained by these sets of cutting devices. The treatment needed may
differ from patient to patient and other patterns may be
conceivable using the concept of inserting cutting devices into
blood vessels adjacent the heart.
[0116] In FIG. 16, the first, second, third, fourth and fifth
cutting devices 30, 38, 54, 68, 82 having been inserted into the
four PVs are shown. The cutting devices 30, 38, 54, 68, 82 are
shown in an intermediate shape, which they present shortly after
having been delivered to the desired positions and before any
penetration of heart wall tissue has begun. The tubular parts 40,
56, 70, 84 of the second, third, fourth and fifth cutting devices
38, 54, 68, 82 have expanded to abut the wall of its respective PV.
The cutting arms of the second, third, fourth and fifth cutting
devices 38, 54, 68, 82 have been diverted from the axial direction
of the tubular part to abut the inside of left atrial wall of the
heart. The second cutting device 38 inserted into the LIPV is shown
having a cutting arm 50 extending to the mitral valve. The third
cutting device 54 inserted into the RIPV has a cutting arm 66
extending to the CS. Thus, instead of forming the cuts 12 and 14
according to FIG. 3, cuts are formed from the LIPV and the RIPV to
the CS. These cuts 12 and 14 are very difficult to accomplish using
the technique of inserting cutting devices into the blood vessels.
However, these cuts may be replaced by the more easily accomplished
cutting pattern formed by the arms 50 and 66 in combination with a
cut formed by the first device 30 inserted into the CS when
expanded out of the CS. Thus, with the arms 50 and 66 in direct
contact with the first cutting device 30 inserted in the CS, the
same effect as from the cuts 12 and 14 in FIG. 3 is achieved. The
second cutting device 38 inserted into the LIPV is further shown
having a cutting arm extending to the LSPV. The third cutting
device 54 inserted into the RIPV is further shown having a cutting
arm extending to the RSPV. The fourth cutting device 68 inserted
into the LSPV is shown having a cutting arm 80 extending to the
LAA. The fifth cutting device 82 inserted into the RSPV is shown
having a cutting arm extending to the fourth cutting device 68. The
cutting arms of the cutting devices 38, 54, 68, 82 may be arranged
in any desired combination between the cutting devices 38, 54, 68,
82 forming connections between the cutting devices 38, 54, 68, 82.
However, the cutting arms may also be arranged freely, without
necessarily having contact to another cutting device.
[0117] In FIG. 17, the cutting devices shown in FIG. 16 are shown
after the change of shape of the devices has occurred. Now, the
second, third, fourth and fifth cutting devices 38, 54, 68, 82 have
expanded out of the respective PVs and the treated tissue around
the orifices of the PVs is shown in shading. Further, the cutting
arms have penetrated the heart tissue and have created cutting
lines between the PVs, from the LIPV to the mitral valve, from the
LSPV to the CS, and from the LSPV to the LAA orifice.
[0118] In FIGS. 18-21, different embodiments of the seventh cutting
device 100 inserted into the SVC and the IVC is shown. In FIG. 18,
the first and second pieces 102, 104 of the seventh cutting device
100 are shown being inserted at the orifices of the SVC and the
IVC. The first and second pieces 102, 104 will treat the heart
tissue around the orifices of the SVC and the IVC, respectively. In
FIG. 19, the second piece 104 is shown comprising a cutting arm
122, which extends from the orifice of the IVC into the orifice of
the CS, whereby the cutting arm 122 penetrates heart tissue of the
right atrium free wall. In FIG. 20, the seventh cutting device 100
is shown comprising the connecting cutting arm 110, which extends
between the first piece 102 inserted into the SVC and the second
piece 104 inserted into the IVC. The connecting cutting arm 110
will penetrate heart tissue in the right lateral aspect and the
right lateral to posterior aspect of the right atrial wall. In FIG.
21, the seventh cutting device 100 is shown comprising a branch 112
of the connecting cutting arm 110. The branch 112 extends from a
point on the connecting cutting arm 110 laterally, creating a
vertical cut outwards in the lateral right atrium wall.
Alternatively, this branch 112 may be arranged as a further cutting
arm extending from the first piece 102 inserted into the SVC.
[0119] In FIGS. 22-23, the first, second, third, fourth, fifth, and
seventh cutting devices 30, 38, 54, 68, 82, 100 are shown inserted
into the CS, the PVs and the IVC and the SVC, respectively. The
cutting devices are shown in an intermediate state corresponding to
the state shown in FIG. 16. Both FIGS. 22 and 23 illustrate cutting
arms between the PVs and from the LIPV past the first cutting
device 30 in the CS extending to the mitral valve. Thus, the first
cutting device 30 inserted in the CS provides a support for the
cutting arms extending from the PVs for stabilizing the position of
the cutting arms after the change of shape of the cutting devices
has been completed. The first cutting device 30 inserted into the
CS has, at least partly, an elliptic cross-section enabling the
first cutting device 30 to penetrate tissue close to the mitral
valve. Also, there is a cutting arm 122 extending from the IVC to
the orifice of the CS. In FIG. 22, there is shown the connecting
cutting arm 110 between the SVC and the IVC, whereas this
connecting cutting arm is not present in FIG. 23. The cutting
patterns shown in FIGS. 22 and 23 illustrate cutting patterns that
will effectively block propagation of undesired electrical signals
in the heart tissue for most patients suffering from disorders to
the heart rhythm regulation system. Thus, inserting cutting-devices
to create these cutting patterns may effectively treat most
patients suffering from disorders to the heart rhythm regulation
system. However, these cutting patterns do not illustrate treatment
of the atrial appendages, as will be shown in FIGS. 24-26. It
should be appreciated that the cutting pattern of FIGS. 22 and 23
may be supplemented with this treatment of the atrial
appendages.
[0120] In FIGS. 24-26, there is shown the sixth cutting devices 94
inserted into the LAA and the RAA. As shown in FIGS. 24a-b in
cross-section, the sixth cutting device 94 is inserted at the
orifice of the appendage (FIG. 24a) and expanded at this position
to penetrate through the heart wall (FIG. 24b). The sixth cutting
device 94 has an elliptic cross-section to fit to the shape of the
appendage. In FIG. 25, sixth cutting devices 94 are shown inserted
into the LAA and the RAA. The sixth cutting device 94 inserted into
the LAA is shown having a cutting arm 124 extending to the LSPV,
and the sixth cutting device 94 inserted into the RAA is shown
having a cutting arm extending along the lateral right atrium wall.
In FIG. 26, the sixth cutting device 94 is shown inserted into the
LAA. This sixth cutting 94 device has no cutting arm; instead a
fourth cutting device 68 inserted into the LSPV is shown having a
cutting arm 80 extending to the LAA. The sixth cutting device 94
inserted into the LAA has a film or membrane 98 covering an end of
its tubular part 96 at the LAA orifice. This film or membrane 98
will exclude the LAA from blood contact with the rest of the heart
and thereby prohibit migration of thrombus or clot formation from
the LAA to, for instance, the brain.
[0121] Now, a system for delivery of a cutting device into a
desired position in a blood vessel adjacent the heart will be
described. Each cutting device may be inserted into its desired
position using such a delivery system. The delivery system allows a
precise placement of each cutting device into the heart and the big
vessels of the body. The delivery system has a restraining device,
which keeps the cutting device in its temporary shape. This allows
insertion into the blood vessel through catheters having a small
bore, making minimal trauma to the patient. The restraining device
may be a restraining tube, into which the cutting device is forced
in its temporary shape. By cooling the cutting device, in case of a
cutting device made of Nitinol, it may be easier to force the
cutting device into the restraining tube. Once inserted into the
desired position, the cutting device may be pushed out of the
restraining tube by means of a piston or the cutting device may be
released by retracting the restraining tube from its position over
the cutting device. In case of a cutting device made of Nitinol,
the cutting device may also be restrained by cooling to prevent it
from obtaining a transition temperature trigging the change of
shape. Thus, the cutting device may be restrained by cooling during
insertion into the desired position and released by suspension of
the cooling when inserted at the desired position. In WO 03/022179,
such a delivery system is described in more detail.
[0122] Now, a method for treating a patient having a disorder to
the heart rhythm regulation system will be described. The patient
is prepared for operation and operation is performed in an
environment allowing visualization of the heart and the attached
big vessels using fluoroscopy and ultrasound according to
conventional techniques.
[0123] The operation is started by making a puncture of a vein
providing an access point to the vascular system of the patient
according to conventional techniques. Usually, the femoral vein in
the groin, as illustrated in FIG. 27, the subclavian vein on the
chest, or the internal or external jugular vein on the neck, as
illustrated in FIG. 28, is used. However, other smaller veins may
be used instead. Also, in difficult cases when the pulmonary veins
cannot be accessed from the vein, arterial access through the
femoral artery in the groin may be used, as illustrated in FIG. 29.
This method will, however, not be further discussed here. A
delivery system is used for inserting the above described cutting
devices into blood vessels adjacent the heart. First, an introducer
sheath 130 of the delivery system is inserted at the puncture
providing an access route into the vascular system. Then, a
diagnostic catheter of the delivery system is inserted through the
introducer sheath 130 into the vascular system. The diagnostic
catheter is manoeuvred through the vascular system into the CS.
Next, a guide wire 132 of the delivery system is inserted through a
channel of the diagnostic catheter into the CS and all the way to
the vein parallel to the left anterior descending artery of the
heart, close to the apex of the heart. The guide wire 132 is
inserted as far as possible into the vascular system to be firmly
positioned. Thereafter, the diagnostic catheter is withdrawn from
the patient. The guide wire 132 will then extend from outside the
patient into the patient via the access point and inside the
patient to the CS, as illustrated in FIG. 30.
[0124] A guide catheter 134 of the delivery system is now inserted
over the guide wire 132 so that the guide catheter 134 is
positioned with its tip at the orifice of the CS, as illustrated in
FIG. 31. Now, there is a guide wire 132 extending from the outside
of the patient and the guide catheter 134, through the guide
catheter 134, through the CS, the great cardiac vein and the
anterior vein parallel to the LAD all the way to the apex of the
heart.
[0125] Referring to FIG. 32, a delivery catheter 136 of the
delivery system for carrying the first cutting device 30 into the
desired position has a guide wire channel throughout its length.
The end of the guide wire 132 outside the patient is then inserted
into the guide wire channel of the delivery catheter 136, whereby
the delivery catheter 136 may be inserted over the guide wire 132
and inside the guide catheter 134 into the CS. The delivery
catheter 136 has an inner part providing the guide wire channel and
carrying the cutting device at a distal portion. The delivery
catheter 136 may further comprise an outer, restraining part, which
covers the cutting device and keeps it in a contracted, temporary
state. The restraining part may be axially displaceable in relation
to the inner part. Thus, the restraining part may be retracted for
releasing the cutting device. In this way, the first cutting device
30 is inserted into the CS and may be located in its desired
position. A correct position is when the distal end 34 of the first
cutting device 30 is positioned within the CS beyond the LIPV next
to the CS and the proximal end 36 of the first cutting device 30 is
closer to the orifice of the CS than the RIPV. Preferably, the
first cutting device 30 extends all the way to the orifice of the
CS. Without moving the first cutting device 30 away from its
correct position, the first cutting device 30 is released from the
delivery catheter. The first cutting device 30 will then
immediately expand radially until contact is established with the
CS wall, as illustrated in FIG. 32. Thereafter, the delivery
catheter 136 is withdrawn from the patient.
[0126] However, the first cutting device 30 is arranged to change
shape to assume a shape having much larger diameter than the
natural diameter of the CS. Thus, the first cutting device 30 will
expand to its designed, permanent shape and the CS wall will not be
able to prevent the first cutting device 30 from obtaining its
permanent shape. In order to obtain its permanent shape, the first
cutting device 30 will therefore penetrate tissue in the path of
the change of shape. In this way, the first cutting device 30 will
expand to penetrate the heart tissue outside the CS, for instance
the left atrium wall. The penetrated tissue will be killed and
replaced by fibrous tissue, which is not able to transmit
electrical signals. Thus, a block against propagation of undesired
electrical signals may be created in this manner.
[0127] As an option, the first cutting device 30 may be inserted
into the CS in a first separate session of the treatment of a
patient. Thus, this first cutting device 30 may be allowed to be
well-anchored in the tissue around the CS, before other cutting
devices are inserted. This is suitable since some of the other
cutting devices are adapted to contact the first cutting device 30
inserted into the CS in order to stabilize and fix their positions.
The first cutting device 30 will be well-anchored within a few
weeks, typically within three weeks. In this time the first cutting
device 30 has penetrated the tissue around the CS and is firmly
embedded by the tissue fixing its position. Then, the patient will
come back for a second session of the treatment. Thus, a puncture
is again made into a vein for allowing access again to the vascular
system. However, all the cutting devices may alternatively be
inserted during one session.
[0128] Now, a guide wire 140 is advanced inside a diagnostic
catheter into the left atrium (LA), as illustrated in FIGS. 33 and
34. In order to access the LA, the atrial septum between the LA and
the right atrium (RA) must be penetrated. If the patient has a
patent foramen ovale (PFO, FIG. 33), which is an opening between
the LA and the RA that is normally only present during the fetal
period in humans, this may be used and enlarged, for instance by
means of a balloon catheter (not shown). If no PFO is present (FIG.
34), a small opening 142 must first be created by means of a long
flexible needle passed through a diagnostic catheter inside the
access vein. Again, the opening 142 in the atrial septum may be
enlarged by means of a balloon. Once the needle is inside the LA,
the catheter is passed over the needle into the LA and the needle
is retracted. A guide wire 140 may now be advanced through the
catheter into the LA and further into the LIPV.
[0129] Referring now to FIGS. 35-37, the release of a cutting
device will be generally described. Thus, having now placed the
guide wire 140, the second cutting device 38 may be inserted to its
desired position using a guide catheter extending to the LIPV
orifice and a delivery catheter 144, as illustrated in FIG. 35, in
a similar manner as for the insertion of the first cutting device
30. The delivery catheter 144 has an inner part 146 providing the
guide wire channel. The tubular part 40 of the second cutting
device 38 is arranged in front of the inner part 146 such that the
inner part 146 of the delivery catheter 144 pushes the tubular part
40 in front of it. The delivery catheter 144 may further comprise
an outer, restraining part 148, which covers the cutting device and
keeps it in a contracted, temporary state. The restraining part 148
may be axially displaceable in relation to the inner part 146.
Thus, the restraining part 148 may be retracted for releasing the
cutting device 38. The delivery catheter 144 has a marker on the
catheter outside the patient, as well as a x-ray marker 149 visible
on the fluoroscopy, indicating securely the orientation of the
cutting arm 50 of the second cutting device 38. The second cutting
device 38 is now rotated into a position where it will change shape
in such a way that the cutting arm 50 will extend to contact and be
supported by the first cutting device 30, which has been inserted
previously. The second cutting device 38 is advanced into a
position where the atrial end 48 of the second cutting device 38 is
still outside the LIPV orifice. When the correct position of the
second cutting device 38 is confirmed by means of fluoroscopy
and/or ultrasound, the distal end of the second cutting device 38
is released from the delivery catheter far inside the PV, whereby
the distal end will expand radially to fix the position of the
second cutting device 38. Next, a mid portion of the second cutting
device 38 and the atrial end 48 is released, as illustrated in FIG.
36. Now, the cutting arm 50 is released, as illustrated in FIG. 37,
and allowed to assume its radial extension from the tubular part
40, whereby it will penetrate the heart wall to contact the first
cutting device 30.
[0130] Now, the guide wire 140 is retracted into the LA. The
diagnostic catheter is inserted again and guided into the RIPV,
whereby the guide wire 140 may be inserted into the RIPV.
Thereafter, the diagnostic catheter is withdrawn from the patient.
Then, the third cutting device 54 is inserted using a guide
catheter extending to the RIPV orifice and a delivery catheter 144
in a manner similar to the insertion of the second cutting device
38. Thus, the orientation of the cutting arm 66 of the third
cutting device 54 is determined in the same manner as for the
second cutting device 38. Having correctly positioned the third
cutting device 54, the tubular part 56, the atrial end 64 and the
cutting arm 66 of the third cutting device 54 are released in a
manner similar to the release of the second cutting device 38. Now,
the cutting arm 66 is released and allowed to assume its radial
extension from the tubular part 56, whereby it will penetrate the
heart wall to contact the first cutting device 30.
[0131] Thereafter, the guide wire 140 is again retracted into the
LA and inserted into the LSPV, as illustrated in FIG. 38. Then, the
fourth cutting device 68 is inserted using a guide catheter 150
extending to the LSPV orifice and a delivery catheter 144, as
illustrated in FIG. 39, in a manner similar to the insertion of the
second and third cutting devices 38, 54. Thus, the orientation of
the cutting arm 80 of the fourth cutting device 68 is determined in
the same manner as for the second and third cutting devices 38, 54.
The fourth cutting device 68 may have two cutting arms, which are
adapted to extend towards the second cutting device 38 and towards
the LAA. Having correctly positioned the fourth cutting device 68,
the tubular part 70, the atrial end 78 and the one or two cutting
arms 80 of the fourth cutting device 68 are released in a manner
similar to the release of the second and third cutting devices 38,
54, as further illustrated in FIG. 40. Now, the cutting arms are
released and allowed to assume their radial extension from the
tubular part 70, whereby they will penetrate the heart wall to
contact the second cutting device 38 or extend to the orifice of
the LAA, respectively.
[0132] Again, the guide wire 140 is retracted into the LA and
inserted into the RSPV. Then, the fifth cutting device 82 is
inserted using a guide catheter 150 extending to the RSPV orifice
and a delivery catheter 144 in a manner similar to the insertion of
the second, third and fourth cutting devices 38, 54, 68. Usually,
the fifth cutting device 82 has no cutting arm and therefore only
the axial position of the fifth cutting device 82 needs to be
determined. Having correctly positioned the fifth cutting device
82, the tubular part 84, and the atrial end 92 of the fifth cutting
device 82 are released in a manner similar to the release of the
second, third, and fourth cutting devices 38, 54, 68.
[0133] Once again, the guide wire 140 is retracted into the LA and
now inserted into the LAA. Then, the sixth cutting device 94 is
inserted using a guide catheter 150 extending to the LAA orifice
and a delivery catheter 144 in a manner similar to the insertion of
the other cutting devices. The sixth cutting device 94 is advanced
into a position where the entire sixth cutting device 94 is inside
the LAA, and a proximal end of the sixth cutting device 94 is
adjacent to the LAA orifice. The delivery catheter 144 has a marker
on the catheter outside the patient, as well as a x-ray marker 149
visible on the fluoroscopy, indicating securely the orientation of
the sixth cutting device 94 such that the elliptic shape of the
sixth cutting device 94 may be oriented in correspondence to the
elliptic shape of the LAA. When the correct position of the sixth
cutting device 94 is confirmed by means of fluoroscopy, a distal
end of the sixth cutting device 94 is released from the delivery
system far inside the LAA, whereby the distal end will expand
radially towards the wall of the LAA to fix the position of the
sixth cutting device 94. Next, a mid portion of the sixth cutting
device 94 and a proximal end are released. Now, the sixth cutting
device 94 is allowed to change its shape to cut through the heart
wall of the LAA.
[0134] Now, the guide wire 140 is retracted from the LA into the RA
and inserted into the RAA. Then, another sixth cutting device 94 is
inserted using a guide catheter 150 extending to the RAA orifice
and a delivery catheter 144 in a manner similar to the insertion of
the other cutting devices. The other sixth cutting device 94 is
advanced into a position where the entire sixth cutting device 94
is inside the RAA, and a proximal end of the sixth cutting device
94 is adjacent to the RAA orifice. The position of the sixth
cutting device 94 is determined in a manner similar to the
positioning of the sixth cutting device 94 inserted into the LAA.
When the correct position of the sixth cutting device 94 is
confirmed, the sixth cutting device 94 inserted into the RAA is
released in a manner similar to the release of the sixth cutting
device 94 inserted into the LAA. Now, the sixth cutting device 94
is allowed to change its shape to cut through the heart wall of the
RAA.
[0135] Next, the guide wire 140 is retracted from the RAA into the
RA. If the access point to the vascular system was created in the
upper part of the body, the guide wire 140 extends through the SVC
into the RA. Then, the guide wire 140 is further inserted into the
IVC, as illustrated in FIG. 41. On the other hand, if the access
point to the vascular system was created in the lower part of the
body, the guide wire 140 extends through the IVC into the RA. Then,
the guide wire 140 is further inserted into the SVC. Thereafter,
the seventh cutting device 100 is inserted using a guide catheter
150, as illustrated in FIG. 42, and a delivery catheter 144 in a
manner similar to the insertion of the other cutting devices. The
seventh cutting device 100 is placed in position in the IVC, SVC
and the RA, as illustrated in FIG. 43. The delivery catheter 152
carries the seventh cutting device 100 on the inner part 154 of the
catheter 152. The inner part 154 comprises stops 156, which prevent
the seventh cutting device 100 from being axially displaced from
the inner part 154 during insertion of the device. Again, the
cutting device 100 is kept in a contracted, temporary state by
means of a restraining part 158. The correct orientation of the
seventh cutting device 100 is obtained in a manner similar to the
positioning of the second, third and fourth cutting devices 38, 54,
68. The seventh cutting device 100 has now been rotated into a
position where it will change shape in such a way that its cutting
arm or cutting arms 122 will extend in intended directions. Thus,
the seventh cutting device 100 may comprise a cutting arm 122 that
extends towards the orifice of the CS and/or a branch 112 that
extends from the connecting cutting arm 110 of the seventh cutting
device 100 towards the lateral wall of the RA. When the correct
position of the seventh cutting device 100 is confirmed by means of
fluoroscopy, a distal end of the seventh cutting device 100 in the
delivery catheter 152 is released from the delivery catheter 152 in
the IVC or SVC, depending on where the distal end of the delivery
catheter is placed. Thereafter, the connecting cutting arm 110 is
released and finally a proximal end of the seventh cutting device
100 is released, as illustrated in FIG. 44.
[0136] Now, the guide wire 140 and the delivery catheter 152 is
retracted outside the patient, since all parts of the treatment kit
have been implanted.
[0137] On special indication, for instance when it is difficult to
place the guide wire inside the PVs, an arterial access may be used
instead. The insertion technique is identical, except that the
access to the vascular system is achieved by puncture of an artery
and that the cutting devices are delivered through the arterial
system instead of through the venous system. After puncture of the
artery, a catheter is advanced through the aorta and passed by the
aortic valve into the left ventricle and finally into the LA. The
guide wire is advanced into the desired PV and the insertion of the
cutting device may then be achieved in the manner described
above.
[0138] The cutting devices have now been released such that they
may change their shapes to obtain their permanent shapes. During
the change of shape, each cutting device will penetrate heart
tissue in the path of the change of shape. Thus, the cutting
devices will now create the cutting pattern intended for forming
blocks against propagation of undesired electrical signals in the
heart. After the cutting devices have made their change of shape,
the needed effect of the cutting devices on the heart tissue is
completed. Thus, if the cutting devices are made of resorbable
shape memory polymers, the cutting devices will be resorbed a time
after termination of the cutting procedure. This time for
resorption can be set by determination of the different ingredients
of polymers and also by means of external altering, for instance by
means of x-ray radiation, ultrasound, electron beams, or light of a
defined wavelength, setting the time of the polymers to be
resorbed. However, the cutting devices may also be left in the body
after the change of shape, or only some of the cutting devices may
be resorbed.
[0139] It should be emphasized that the preferred embodiments
described herein is in no way limiting and that many alternative
embodiments are possible within the scope of protection defined by
the appended claims.
* * * * *