U.S. patent application number 12/800924 was filed with the patent office on 2011-11-24 for surgical clip and surgical method for treating an aneurysm.
This patent application is currently assigned to Aesculap AG. Invention is credited to Olaf Hegemann, Eric S. Nussbaum, Klaus-Dieter Steinhilper.
Application Number | 20110288571 12/800924 |
Document ID | / |
Family ID | 44973096 |
Filed Date | 2011-11-24 |
United States Patent
Application |
20110288571 |
Kind Code |
A1 |
Steinhilper; Klaus-Dieter ;
et al. |
November 24, 2011 |
Surgical clip and surgical method for treating an aneurysm
Abstract
The present invention relates to a surgical clip comprising a
first arm and a second arm, the first and second arms having first
and second clamping surfaces facing each other, and the first and
second arms being mounted for movement relative to each other, and
further comprising a distance retaining device for keeping the
first and second arms permanently spaced from each other. The
present invention also relates to a surgical method for treating an
aneurysm, the method comprising: applying a surgical clip to the
aneurysm, the clip comprising a first arm and a second arm, aid
first and second arms having first and second clamping surfaces
facing each other for clamping the aneurysm therebetween, the first
and second arms being mounted for movement relative to each other,
and the first and second arms being kept permanently spaced from
each other, wherein the aneurysm is clamped between the arms kept
permanently spaced from each other.
Inventors: |
Steinhilper; Klaus-Dieter;
(Tuttlingen, DE) ; Hegemann; Olaf; (Dortmund,
DE) ; Nussbaum; Eric S.; (Saint Louis Park,
MN) |
Assignee: |
Aesculap AG
Tuttlingen
DE
|
Family ID: |
44973096 |
Appl. No.: |
12/800924 |
Filed: |
May 24, 2010 |
Current U.S.
Class: |
606/158 |
Current CPC
Class: |
A61B 17/122 20130101;
A61B 17/1227 20130101 |
Class at
Publication: |
606/158 |
International
Class: |
A61B 17/122 20060101
A61B017/122 |
Claims
1. A surgical clip comprising a first arm and a second arm, said
first and second arms having first and second clamping surfaces
facing each other, and said first and second arms being mounted for
movement relative to each other, and further comprising a distance
retaining device for keeping said first and second arms permanently
spaced from each other.
2. The surgical clip of claim 1, wherein said distance retaining
device is designed such that in a basic position in which no
extraneous forces are acting on the clip, said first and second
arms are spaced from each other.
3. The surgical clip of claim 1, further comprising a restoring
device, wherein said restoring device is arranged and constructed
such that said first and second arms are movable away from each
other against a restoring force exerted by said restoring
device.
4. The surgical clip of claim 2, further comprising a restoring
device, wherein said restoring device is arranged and constructed
such that said first and second arms are movable from the basic
position to a spread out position in which said first and second
arms are spaced further apart from each other than in the basic
position against the restoring force exerted by said restoring
device.
5. The surgical clip of claim 1, further comprising first and
second connecting sections connected to said first and second arms,
wherein said first connecting section penetrates said second
connecting section.
6. The surgical clip of claim 1, wherein said first and second arms
are pivotable about a pivot axis.
7. The surgical clip of claim 1, wherein said clip comprises first
and second clip parts, said first clip part comprising said first
arm and said second clip part comprising said second arm.
8. The surgical clip of claim 1, further comprising a locking
device for locking said first and second arms in a position
relative to each other.
9. The surgical clip of claim 8, wherein said locking device is
designed such that said first and second arms are movable only from
a spread out position to a clamping position, said first and second
arms being spaced further from each other in said spread out
position than in said clamping position, and said clamping position
defining said basic position.
10. The surgical clip of claim 8, wherein said locking device
comprises locking elements arranged on at least one of said first
and second arms, said locking elements engaging in a locking
position in order to define said clamping position.
11. The surgical clip of claim 1, wherein in the basic position
said first and second clamping surfaces extend parallel to each
other.
12. The surgical clip of claim 1, wherein said first and second
arms are curved.
13. The surgical clip of claim 1, further comprising a stop device
for limiting movement of said first and second arms towards each
other.
14. The surgical clip of claim 1, further comprising a stop device
for limiting movement of said first and second arms away from each
other.
15. The surgical clip of claim 1, further comprising first and
second clamping elements arranged on said first and second clamping
surfaces.
16. A surgical method for treating an aneurysm, said method
comprising: applying a surgical clip to the aneurysm, said clip
comprising a first arm and a second arm, said first and second arms
having first and second clamping surfaces facing each other for
clamping the aneurysm therebetween, said first and second arms
being mounted for movement relative to each other, and said first
and second arms being kept permanently spaced from each other,
wherein the aneurysm is clamped between said arms kept permanently
spaced from each other.
17. The surgical method of claim 16, wherein said clip is applied
to one of a wider-necked, atheromatous, thrombotic, and previously
coiled intracranial aneurysm.
18. The surgical method of claim 16, wherein a microdissection is
carried out in the region of the aneurysm and the necessary
distance between said first and second arms in a closed position of
said clip is estimated or measured.
19. The surgical method of claim 16, wherein said clip is inserted
into the patient's body through an access provided therefor.
20. The surgical method of claim 16, wherein said clip is allowed
to close gradually.
21. The surgical method of claim 16, wherein said clip is allowed
to compress an aneurysm wall against one of atheroma, thrombus and
coils, and then against the opposite aneurysm wall.
22. The surgical method of claim 16, wherein said first and second
arms are moved away from each other against a restoring force
exerted by said clip.
23. The surgical method of claim 16, wherein said first and second
arms are locked in a clamping position relative to each other.
24. The surgical method of claim 16, wherein said first and second
arms are curved.
25. The surgical method of claim 16, wherein first and second
clamping elements are arranged on said first and second clamping
surfaces.
Description
FIELD OF THE INVENTION
[0001] The present invention relates in general to a surgical clip
and, more specifically, to a surgical clip comprising a first arm
and a second arm, the first and second arms having first and second
clamping surfaces facing each other, and the first and second arms
being mounted for movement relative to each other.
[0002] The present invention also relates, in general, to a
surgical method for treating an aneurysm and, more specifically, to
a surgical method for treating an aneurysm, the method comprising:
applying a surgical clip to the aneurysm, the clip comprising a
first arm and a second arm, the first and second arms having first
and second clamping surfaces facing each other for clamping the
aneurysm therebetween, and the first and second arms being mounted
for movement relative to each other.
BACKGROUND OF THE INVENTION
[0003] Aneurysms are abnormal dilatations of blood vessels. A
critical type of aneurysm is a brain aneurysm which is an abnormal
dilatation of one of the blood vessels supplying blood flow to the
brain itself. Aneurysms are felt to start as an area of potential
weakness in the wall of the artery and typically occur at an
arterial branch point. Over time, the natural pulsation of blood
against the area of weakness can gradually cause the weakened area
to dilate or enlarge. This process may be analogized to inflating a
balloon. As the balloon stretches, the wall of the balloon
typically becomes thinner. Eventually, if the wall is stretched too
thin, the balloon bursts. Similarly, if an aneurysm becomes too
thin, the wall bursts allowing blood to escape from the blood
vessels, in particular, the arteries in which the blood is supposed
to be contained. The blood spills into the subarachnoid space, a
potential space surrounding the brain that is normally filled with
cerebrospinal fluid. This aneurysm bleeding or rupture results in
what is known as a subarachnoid hemorrhage (SAH). Unfortunately,
despite best medical efforts, SAH will be fatal in roughly 50% of
the cases, with a significant percentage of patients dying before
they even reach the hospital. Of survivors, approximately one half
are left with permanent disability, for example, a stroke, which
permanently compromises their independence and quality of life.
Once an aneurysm ruptures, if it does not stop bleeding on its own
within seconds, the patient generally dies. After an aneurysm has
bled once, the risk of rebleeding is very high, and each hemorrhage
carries at least a 50% mortality rate so urgent treatment is
generally performed to prevent rebleeding. In addition, aneurysms
are now being found prior to rupture as sophisticated imaging
techniques such as magnetic resonance imaging, magnetic resonance
angiography, and computerized tomographic angiography are gaining
widespread use. These non-invasive techniques allow for the
demonstration of an aneurysm before it bleeds, and their increasing
use has led to the discovery of an unexpectedly significant number
of patients with unruptured, asymptomatic lesions.
[0004] In general, there are two forms of treatment for a brain
aneurysm, whether it has bled or not. Open microsurgery, a
so-called craniotomy, with aneurysm clipping entails opening the
skull and placing a metal clip, usually made from titanium, across
the neck of the aneurysm to reconstruct the normal contour of the
parent artery which harbors the aneurysm. Open clipping procedures
have been performed for almost a century. This is the traditional,
so-called "gold standard" method for treating an aneurysm of the
brain. Once properly clipped, aneurysms rarely recur, and the
patient is generally cured. If the aneurysm has already bled, there
may be consequences of the initial hemorrhage, but the aneurysm
cannot bleed again, and the patient is thus protected from the
insult of a repeat hemorrhage. Over the past 50 years, repeatedly
refined designs of increasingly pure titanium clips have been
manufactured providing the neurovascular surgeon with numerous clip
shape and size choices that can either singly or in combination
address most, but not all, aneurysms.
[0005] The major alternative form of treatment for brain aneurysms
is endovascular coiling. Coiling is a much newer technique that was
introduced in the 1990's. A microcatheter is fed from a puncture
site in the femoral or groin artery up into the carotid or
vertebral arteries, and all the way into the aneurysm itself at the
base of the brain. This is all done while watching the progress of
the microcatheter on a fluoroscope using biplane digital
subtraction angiography. Once the catheter tip is positioned inside
the aneurysm, a tiny platinum wire is fed through the catheter into
the aneurysm. The wire coils up on itself and fills the aneurysm so
that when completed, the coiled aneurysm is essentially full of
wire and no blood can enter the aneurysm from the main parent
artery. This coil mass essentially acts as a physical barrier
preventing blood from entering the aneurysm and reaching the wall
of the aneurysm. Thereby, the aneurysm is prevented from
rupturing.
[0006] Coiling of aneurysms has rapidly gained acceptance as an
important technique in aneurysm treatment. It is minimally
invasive, avoiding the need for an open brain operation, i.e. it
avoids a craniotomy. The patients tend to recover more quickly and
have less down time after the procedure compared with open surgery.
Unfortunately, coiling works best for aneurysms with a narrow neck
that will help prevent the coil mass from herniating back into the
main artery, i.e. the parent artery. In wider necked aneurysms,
such coil protruding into the main artery could result in blockage
of blood supply through the main artery and subsequent stroke. In
addition, many aneurysms will recur or regrow after coiling. As the
blood pumps against the coil mass sitting in the aneurysm, it tends
to "compact" the coils themselves out towards the dome of the
aneurysm, and then blood flow can once again enter the aneurysm,
and the patient is again at risk for bleeding from the thin wall of
the aneurysm. Nevertheless, the great appeal and relative ease of
coiling as opposed to open surgery has resulted in a substantial
percentage of aneurysms being treated with endovascular
coiling.
[0007] In general, aneurysm clips are comprised of two blades or
arms that are parallel and opposed to each other in the resting
position. A clip applying device which opens the clip blades is
used to allow the clip, which can be opened and closed like a
clothespin, to be applied to the aneurysm. As the clip is allowed
to close, the blades return to the parallel, perfectly opposed
position, collapsing the soft aneurysm between the blades. When
applied properly down at the base of the aneurysm neck, the blades
completely stop any blood flow into the now "empty sac" of the
aneurysm which has been cured. When clipping an aneurysm, the
surgeon relies on the softness of the wall of the aneurysm which
allows the clip blades to close in opposition to one another.
Anything that prevents the clip itself from closing properly may
prevent proper clipping of an aneurysm. Because the blades of the
clip have a strong so-called "closing strength" a force will be
exerted against any such an obstructing item as the blades attempt
to resume their resting, closed position. Those aneurysms that are
not soft-walled represent the crux of the problem addressed by this
development.
[0008] An aneurysm may not allow a clip to close properly because
there is atheroma or calcium, which form a hardening of the artery
within the wall of the aneurysm itself, because there is organized
hematoma or thrombus within the aneurysm itself, or because the
aneurysm is filled with coils from a previous endovascular
treatment. When traditional clips fail because of non-compliance of
the aneurysm, a dangerous situation is created. The clip can slip
back off the aneurysm, it can be forced down onto the neck of the
aneurysm blocking flow through the main artery or its branches, or
it can tear through the wall of the aneurysm with disastrous
consequences. As coiling has become more common, and as coiling has
been used increasingly for small, simple aneurysms, those aneurysms
that are referred for open surgery are increasingly large and giant
aneurysms with atheromatous, calcified walls, intraluminal
thrombus, and previously coiled aneurysms in which the coils have
failed. These are precisely the subgroups of aneurysms that are
hardest to treat using conventional clip technology, for the
reasons stated above. A better option for surgical aneurysm
obliteration is clearly needed for these most difficult and
challenging lesions.
[0009] As described above, aneurysms are generally treated with
either clipping or coiling. The large and giant aneurysms are the
ones most likely to have thick non-compliant walls, and these
aneurysms represent a serious management challenge. Also, the
growing number of previously coiled aneurysms that have failed and
recurred is increasing exponentially. There are no optimal
treatments for these lesions today. Some of these aneurysms can be
clipped using very large, long clips that have a very high closing
pressure. The aneurysms can be "crushed" with a forceps or clamp
first to allow the clips to close, but this is a dangerous maneuver
that can rupture the aneurysm or shower clot out of the aneurysm
into the blood supply causing a stroke. Some aneurysms can be
treated by temporarily stopping blood flow to the aneurysm, cutting
the aneurysm open, and removing the thicker portion of the wall
with any associated thrombus. The aneurysm can then be closed by
over-sewing the opening, so-called aneurysmorrhaphy, or with very
large clips. Unfortunately, stopping the blood flow to the
aneurysm, even temporarily, may mean stopping the blood flow to the
normal brain which can cause a stroke. Even if no stroke occurs
from the temporary arterial occlusion, the wall of the aneurysm may
be brittle or friable and may not be repairable once opened
resulting in disaster.
[0010] Still other aneurysms require permanent occlusion of the
entire involved artery, relying on collateral blood supply to
prevent a stroke or performing a delicate brain bypass surgery to
bring new blood supply to the part of the brain that was being fed
by the artery that must be sacrificed. If the bypass is
unsuccessful, the result is usually a severe stroke. Some aneurysms
can be re-filled with coils, but many will only regrow yet again
over time, at which point the problem may be even worse. Finally,
some aneurysms can be wrapped with gauze to toughen the wall and
decrease future risk of bleeding. This is the least reliable way to
treat an aneurysm, and there is little data on long-term follow-up
after wrapping. The aneurysm is essentially left unsecured with the
potential for future bleeding.
[0011] In short, there are no good treatment methods currently
available for these vexing lesions.
[0012] As described in detail above, all current treatment options
are a high risk and dangerous. The complication rates including
stroke and death rates in these patients are many times higher than
in the patients with simple smaller aneurysms. This is simply a
reflection of the limited available technology to treat these
lesions. Because there is nothing better available, surgeons are
forced to apply a technology that is not designed to treat properly
these lesions in particular. Clips which depend on a soft,
compliant aneurysm wall to close are generally not intended for and
are no match for a giant, atheromatous aneurysm or an aneurysm full
of coils.
[0013] Therefore, any new method designed to treat this subgroup of
aneurysms will have to address the wall non-compliance that
prevents traditional clips from closing properly. It should be able
to address the problems of a thick wall as well as a mass of coils
within the aneurysm, both of which will work against the closure of
all standard aneurysm clips.
SUMMARY OF THE INVENTION
[0014] In accordance with the invention, a surgical clip comprises
a first arm and a second arm, the first and second arms having
first and second clamping surfaces facing each other, and the first
and second arms being mounted for movement relative to each other,
and further comprises a distance retaining device for keeping the
first and second arms permanently spaced from each other.
[0015] Furthermore, in accordance with the invention, a surgical
method for treating an aneurysm comprises: applying a surgical clip
to the aneurysm, the clip comprising a first arm and a second arm,
the first and second arms having first and second clamping surfaces
facing each other for clamping the aneurysm therebetween, the first
and second arms being mounted for movement relative to each other,
and the first and second arms being kept permanently spaced from
each other, wherein the aneurysm is clamped between the arms kept
permanently spaced from each other.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The foregoing summary and the following description may be
better understood in conjunction with the drawing figures, of
which:
[0017] FIG. 1: shows a perspective view of a first embodiment of a
surgical clip applied to an aneurysm;
[0018] FIG. 2: shows a perspective view of the surgical clip shown
in FIG. 1 in a spread out position;
[0019] FIG. 3: shows the surgical clip shown in FIG. 2 in a
clamping position;
[0020] FIG. 4: shows a further embodiment of a surgical clip in a
basic position;
[0021] FIG. 5: shows a perspective view similar to FIG. 1 of a
further embodiment of a surgical clip applied to an aneurysm;
and
[0022] FIG. 6: shows a perspective view of the surgical clip shown
in FIG. 5 in a basic position.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION
[0023] Although the invention is illustrated and described herein
with reference to specific embodiments, the invention is not
intended to be limited to the details shown. Rather, various
modifications may be made in the details within the scope and range
of equivalence of the claims and without departing from the
invention.
[0024] The present invention relates to a surgical clip comprising
a first arm and a second arm, the first and second arms having
first and second clamping surfaces facing each other, and the first
and second arms being mounted for movement relative to each other,
and further comprising a distance retaining device for keeping the
first and second arms permanently spaced from each other.
[0025] The surgical clip in accordance with the present invention
is, in particular, designed in the form of a compression clip for
the treatment of wider necked, atheromatous, thrombotic and/or
previously coiled intracranial aneurysms. Its unique feature is
that it comprises a distance retaining device for keeping the first
and second arms permanently spaced from each other. In other words,
in a closed position, the first and second arms which are also
called clip blades do not rest in a parallel, perfectly opposed
fashion. The distance retaining device allows separation of the
blades by a preset so-called "opening distance" or "opening
diameter" ("O.D."). Thus, in the closed position, the blades do not
actually contact one another and may not be parallel to one
another. Because the arms of the surgical clip never contact one
another, there is no traditional measurement of a so-called
"closing force" associated with the clip design according to the
present invention. Rather, the amount of pressure applied to the
aneurysm wall will depend on the amount of intervening tissue or
material as well as the thickness and consistency of the wall
itself.
[0026] It is advantageous for the distance retaining device to be
designed such that in a basic position in which no extraneous
forces are acting on the clip, the first and second arms are spaced
from each other. Such a design avoids forcing the aneurysm into a
flat pancake-like shape.
[0027] In accordance with a preferred embodiment of the invention,
the surgical clip further comprises a restoring device which is
arranged and constructed such that the first and second arms are
movable away from each other against the restoring force exerted by
the restoring device. The restoring device easily allows movement
of the arms back into a basic position in which no extraneous
forces are acting on the clip. For applying the surgical clip to
the aneurysm to be treated the arms of the clips have only to be
moved away from each other against the force of the restoring
device, which allows automatic transfer of the surgical clip into a
clamping position.
[0028] Preferably, the surgical clip further comprises a restoring
device which is arranged and constructed such that the first and
second arms are movable from the basic position to a spread out
position in which the first and second arms are spaced further
apart from each other than in the basic position against the
restoring force exerted by the restoring device. The restoring
device allows automatic transfer of the surgical clip from the
spread out position back into the basic position.
[0029] Preferably, the restoring device is constructed such that in
at least one of the spread out position and the basic position, the
first and second arms are biased towards each other. Such a design
of the clip diminishes or even eliminates the dangerous tendency of
traditional clips to slip down, which could result in an occlusion
or narrowing of the parent artery or branch artery or perforation
of the blood vessel.
[0030] A particularly simple design of the clip is made possible by
the restoring device comprising a spring coil.
[0031] Preferably, the spring coil comprises one to five windings.
Depending on the number of windings, a closing force can be set
when manufacturing the clip. In order to improve the stability of
the clip, it is advantageous for the first and second arms and the
restoring device to be made of one piece.
[0032] A possible twisting movement of the first and second arms
relative to each another can be minimized by the surgical clip
further comprising first and second connecting sections connected
to the first and second arms, with the first connecting section
penetrating the second connecting section.
[0033] A particularly simple construction of the clip is made
possible by the second arm having a through-opening and the first
arm penetrating the through-opening.
[0034] Preferably, the through-opening is in the form of a slit for
guiding relative movement of the first and second arms in a
clamping plane. Such a design allows easy perfect application of
the clip to the aneurysm to be treated. Furthermore, a relative
movement between the first and second arms can be perfectly
guided.
[0035] In principle, it would be possible for the first and second
arms to be movable relative to each other in parallel. In
particular, for applying the surgical clip during a minimal
invasive surgical procedure, it is advantageous for the first and
second arms to be pivotable about a pivot axis.
[0036] Preferably, the pivot axis is defined by the restoring
device. Such a design enables a very small and compact clip
design.
[0037] It is advantageous for the surgical clip to further comprise
a pivot joint defining the pivot axis. The pivot joint also allows
guidance of a relative movement of the first and second arms.
[0038] A particularly simple design of the surgical clip is made
possible by the pivot joint comprising a pivot pin defining the
pivot axis.
[0039] In accordance with a preferred embodiment of the invention,
the surgical clip comprises first and second clip parts, the first
clip part comprising the first arm and the second clip part
comprising the second arm. In particular, such a design makes it
possible to choose different materials for constructing the
surgical clip.
[0040] To enable an individual design for each of the clip parts,
in particular, of the first and second arms, it is advantageous for
the first and second clip parts to be of two-piece design.
[0041] In accordance with a further preferred embodiment of the
invention, the surgical clip further comprises a locking device for
locking the first and second arms in a position relative to each
other. The locking device allows, in particular, locking of the
first and second arms in a position, which might be defined as a
locking position. Such a unique design of the clip diminishes or
even eliminates the dangerous tendency of traditional clips to be
inadvertently brought back into the spread out position, which
would allow the clip to slip down the aneurysm.
[0042] Preferably, the locking device is of unidirectional design.
This enables the surgical clip to be brought from a spread out
position into a clamping position but not from the clamping
position back into the spread out position. This allows a
relatively simple application of the surgical clip to an
aneurysm.
[0043] It is advantageous for the locking device to be designed
such that the first and second arms are movable only from a spread
out position to a clamping position, the first and second arms
being spaced further from each other in the spread out position
than in the clamping position, and the clamping position defining
the basic position. In other words, the described preferred
surgical clip design allows only a unidirectional movement of the
first and second arms relative to each other from the spread out
position to the clamping position.
[0044] In order to ensure that the surgical clip fits perfectly on
the aneurysm it is advantageous for a distance between the first
and second arms to be minimal in the clamping position.
[0045] Preferably, the locking device comprises locking elements
arranged on at least one of the first and second arms, the locking
elements engaging in a locking position in order to define the
clamping position. The locking elements allow locking of the
surgical clip in the clamping position, in particular, if the
locking elements are designed to provide at least one of a positive
and non-positive engagement of the locking elements.
[0046] A particularly simple design of the locking device is made
possible by the locking elements being in the form of locking
projections and locking receptacles. Preferably, the locking
projections and the locking receptacles are designed to cooperate
with one another.
[0047] The locking elements can easily engage each other if the
locking elements are at least partially flexible or elastic. Such a
design of the locking elements allows provision of a snap-fit
connection for defining the clamping position.
[0048] Preferably, in the basic positions the first and second
clamping surfaces extend parallel to each other. Such a design
easily enables a desired opening distance or opening diameter to be
defined between the arms of the surgical clip.
[0049] In accordance with a preferred embodiment of the invention,
the first and second arms are curved. Such a unique design of the
clip with the clip blades, at rest in the closed or clamping
position, not sitting in the typical parallel opposition,
diminishes or even eliminates the dangerous tendency of traditional
clips to slip down, back off, remain perched in a precarious
partially opened position and/or fail to close.
[0050] In order to perfectly fit around a wider-necked
atheromatous, thrombotic and/or previously coiled intercranial
aneurysm, the first and second arms are curved concavely with
respect to one another. Such a design enables perfect enclosure the
aneurysm to be treated.
[0051] In accordance with a further preferred embodiment of the
invention, the surgical clip further comprises a stop device for
limiting movement of the first and second arms towards each other.
Such a design diminishes or even excludes the danger of rupturing
the aneurysm with the clip.
[0052] It is advantageous for the stop device to define a spread
out position in which a distance between the first and second arms
is maximal. Thus, an undesired contact between the surgical clip
and surrounding tissue which is usually rather weak can be
minimized.
[0053] Moreover, it is expedient for the stop device to define a
clamping position in which a distance between the first and second
arms is minimal. A surgical clip comprising such a stop device can
ensure that a desired opening diameter or opening distance between
the clamping surfaces can be maintained, in particular, in the
clamping position.
[0054] Furthermore, it is preferred if the stop device is designed
such that the first and second arms are movable between a spread
out position and a clamping position, the first and second arms
being spaced further from each other in the spread out position
than in the clamping position. Such a stop device is well-suited
for defining both the spread out position and the clamping
position.
[0055] In accordance with a further preferred embodiment of the
invention, the surgical clip further comprises a stop device for
limiting movement of the first and second arms away from each
other. Such a stop device is preferably effective in the clamping
position in order to ensure that the surgical clip backs off the
aneurysm to which it is applied.
[0056] Moreover, in accordance with another preferred embodiment of
the invention, the surgical clip further comprises first and second
clamping elements arranged on the first and second clamping arms or
surfaces. The first and second clamping elements can increase a
gripping action between the surgical clip and the aneurysm in order
to minimize the dangerous tendency of the clip to slip down the
aneurysm.
[0057] In order to be perfectly applied to the aneurysm, the
clamping elements define first and second clamping element surfaces
facing each other. This allows the clamping elements to surround or
enclose the aneurysm in a desired manner.
[0058] Preferably, the first and second clamping element surfaces
are larger than the first and second clamping surfaces. Such a
design allows, in particular, improvement of a gripping action of
the surgical clip. In particular, the first and second clamping
element surfaces can be larger in width than the first and second
clamping surfaces.
[0059] It is advantageous for the first and second clamping element
surfaces to rest against each other in the basic position. This
ensures that the clamping surfaces of the clip arms remain at the
desired distance from each other.
[0060] In order to provide a perfect fit of the surgical clip in
the region of the aneurysm it is advantageous for the first and
second clamping elements to be in the form of pads.
[0061] Preferably, the first and second clamping elements are of
flexible or elastic design. Such a clamping element design allows
an individual adjustment and a perfect fit of the surgical clip for
treating the aneurysm.
[0062] In accordance with a further preferred embodiment of the
surgical clip, the first and second clamping elements are made from
at least one of a plastic material or a gel. Clamping elements made
from the aforementioned materials can easily adapt to any shape of
an aneurysm.
[0063] The invention further relates to a surgical method for
treating an aneurysm, the method comprising: applying a surgical
clip to the aneurysm, the clip comprising a first arm and a second
arm, the first and second arms having first and second clamping
surfaces facing each other for clamping the aneurysm therebetween,
the first and second arms being mounted for movement relative to
each other, and the first and second arms being kept permanently
spaced from each other, wherein the aneurysm is clamped between the
arms kept permanently spaced from each other.
[0064] Such an improved surgical method for treating an aneurysm
enables the dangerous tendency of traditional clips to slip down or
back off, to be diminished or even eliminated.
[0065] Preferably, the surgical method is carried out by applying
the clip to one of a wider-necked, atheromatous, thrombotic, and
previously coiled intracranial aneurysm. In particular, the
proposed surgical method is advantageous for the aforementioned
indications compared to applying known surgical clips or coiling
the aneurysm.
[0066] Preferably, a microdissection is carried out in the region
of the aneurysm and the necessary distance between the first and
second arms in a closed position of the clip is estimated or
measured. These steps of the surgical method help to improve the
success of the treatment since it is possible to choose a surgical
clip of a size which fits the aneurysm best.
[0067] It is advantageous for the clip to be inserted into the
patient's body through an access provided therefor.
[0068] It is advantageous for the clip to be opened and applied
across one of the base and neck of the aneurysm. The base or the
neck are perfect locations for applying the clip in order to treat
the aneurysm in a desired manner.
[0069] The clip can be applied to the aneurysm in a particularly
simple manner if the clip is opened and applied using a clip
applying device. In particular, if the clip is rather small, using
a clip applying device enables insertion of the surgical clip and
application of it to the aneurysm in a defined manner.
[0070] In order to improve applying the clip to the aneurysm it is
advantageous for the clip to be allowed to close gradually. This
allows gradual adopting of the clip to the aneurysm to be
treated.
[0071] Preferably, the clip is allowed to compress an aneurysm wall
against one of atheroma, thrombus and coils, and then against the
opposite aneurysm wall. This leads to a perfect fit of the surgical
clip on the aneurysm in order to reconstruct the normal contour of
the blood vessel.
[0072] In order to simplify the application of the clip to the
aneurysm it is preferred if the first and second arms are moved
away from each other against a restoring force exerted by the
clip.
[0073] It is advantageous for the first and second arms to be
locked in a clamping position relative to each other. Thus, it can
be ensured that the surgical clip maintains the well-defined
clamping position.
[0074] Preferably, in the clamping position a distance between the
first and second arms is minimal. An adjustment of the surgical
clip in the described manner ensures that the aneurysm wall is not
completely clamped off so that rupture thereof can be avoided.
[0075] It is expedient if the first and second arms of the surgical
clip are curved. Applying a surgical clip with curved arms allows a
perfect fit of the clip of the aneurysm because the arms can
surround the aneurysm, in particular, a base or a neck of the
aneurysm, in a natural way.
[0076] In accordance with a further preferred alternative of the
surgical method in accordance with the present invention, first and
second clamping elements are arranged on the first and second
clamping surfaces. The first and second clamping elements can be
designed such that they fit perfectly around a base or a neck of an
aneurysm.
[0077] The aneurysm can be easily clamped between the clamping
elements if they define first and second clamping surfaces facing
each other.
[0078] A large-area compression can be easily achieved if a
surgical clip is applied which has first and second clamping
element surfaces that are larger than the first and second clamping
surfaces.
[0079] Preferably, in a basic position the first and second
clamping element surfaces rest against each other. Thus, it can be
achieved that the clamping surfaces of the first and second arms
are kept at the desired distance from each other.
[0080] Compression forces exerted by the surgical clip on the
aneurysm can be individually adjusted if the first and second
clamping elements are in the form of pads. Moreover, such a
surgical clip can be easily manufactured.
[0081] The surgical method allows an individual adjustment of the
surgical clip on the aneurysm if the first and second clamping
elements are of flexible or elastic design.
[0082] In order to minimize the danger of a rupture of the aneurysm
wall it is advantageous for the first and second clamping elements
to be made from at least one of a plastic or a gel.
[0083] FIGS. 1 to 3 show a first embodiment of a surgical clip in
the form of an aneurysm clip given the overall reference numeral
10. The clip 10 comprises first and second clip parts 12, 14 which
are linked together by means of a pivot joint 16.
[0084] The second clip part 14 comprises a through-opening 18 in
the form of a slit 20 which allows the first clip part 12 to
penetrate the through-opening 18. The slit 20 defines a clamping
plane which is perpendicular to a pivot axis 22 defined by a pivot
pin 24 which is inserted in a bore extending coaxially through both
the first and second clip parts 12, 14 in the region of the
connection portion. Each of the clip parts 12, 14 defines an arm
26, 28 which can also be called blades. The arms 26, 28 extend from
the pivot joint 16 towards distal ends 30 and 32. Cross sections of
the arms 26, 28 are rectangular-shaped. Side faces of the arms 26,
28 facing towards each other define clamping surfaces 34, 36. The
clamping surfaces 34, 36 may be structured in order to improve a
gripping action thereof. The clamping surfaces 34, 36 and the arms
26, 28 are curved concavely with respect to each other.
[0085] Proximal portions 38, 40 defined by the first and second
clip parts 12, 14 and extending from the pivot joint 16 in a
proximal direction are also concavely curved with respect to one
another. End portions 42 and 44 of the proximal portions 38 and 40
extend towards proximal ends 46, 48 of the first and second clip
parts 12, 14. The end portions 42, 44 are constructed in the form
of a circular arc arranged coaxially with respect to the pivot axis
22.
[0086] An inner surface of the end portion 42 facing towards the
pivot axis 22 carries a plurality of locking elements 50 in the
form of locking teeth 52. A side surface of the end portion 44
facing away from the pivot axis 22 carries a plurality of locking
elements 54 which are designed in the form of locking teeth 56. The
locking teeth 56 are arranged such that they can engage with the
locking teeth 52. The locking elements 50 and 54 jointly define a
locking device 58 which is of unidirectional design.
[0087] In a basic position of the surgical clip 10 the locking
elements 50, 54 are not engaged. A distance 60 which corresponds to
a maximum opening distance between the distal ends 30 and 32 is
maximal in this basic position. Due to the unidirectional design of
the locking device 58 it is only possible to pivot the arms 26 and
28 towards each other in order to reduce the distance 60 between
the distal ends 30 and 32. At the same time, the teeth 52 and 56
mesh with each other. Due to the unidirectional design of the
locking device 58 it is only possible to pivot the arms 26, 28
towards each other. The design of the teeth 52 and 56 prevents
pivotal movement of the proximal portions 38, 40 away from each
other. In order words, the locking device 58 is designed such that
the first and second arms 26, 28 are movable only from a spread out
position which is schematically shown in FIG. 2 to a clamping
position shown by way of example in FIGS. 1 and 3.
[0088] The first and second arms 26, 28 are spaced further from
each other in the spread out position than in the clamping
position. Moreover, the clamping position in which the distance 60
becomes minimal defines a basic position of the aneurysm clip 10.
The locking device 58 in cooperation with the smaller radius of the
proximal portions 38, 40 adjacent to the end portions 42, 44 define
a distance retaining device 62 for keeping the first and second
arms 26, 28 permanently spaced from each other. The distance 60 in
the basic position of the clip 10 as shown in FIGS. 1 and 3 defines
a preset "opening distance" or "opening diameter" abbreviated as
"O.D.".
[0089] The distance retaining device 62 and the locking device 58
form a raster mechanism which holds the clamp in defined positions.
With this raster mechanism it is possible to close the clip 10 in
small increments to the position where it rests perfectly on a neck
78 of the aneurysm 72 without slipping down the artery 88.
[0090] The aneurysm clip 10 further comprises a stop device 64 for
defining the spread out position in which the distance 60 is
maximal. The stop device 64 comprises stop surfaces 66 and 68
defined by inner side surfaces of the slit 20 which face towards
each other and extend generally parallel to the pivot axis. Both in
the spread out position and in the basic position the weakened
joint portion 70 of the first clip part 12 forming a connection
portion either abuts with its distal portion on one of the stop
surfaces 66 and 68.
[0091] The aneurysm clip 10 is used for treating an aneurysm 72 of
a blood vessel 74, in particular, a blood vessel 74 supplying blood
flow to the brain of a patient. The method is described in further
detail below.
[0092] After thorough microdissection of the local anatomy in the
region of the aneurysm 72, the necessary O.D. of the clip 10 in its
closed position or clamping position is estimated or measured
either based on the preoperative imaging studies or using a fine,
specially calibrated measuring tool. The clip 10 is then introduced
into the field, applied across the base 76 or neck 78 of the
aneurysm 72 using a specialized clip applying device not shown in
the figures. The clip 10 is then allowed to close gradually, gently
compressing an aneurysm wall 80 against atheroma and/or thrombus
and/or coils, and then against the opposite aneurysm wall 82. This
effectively "sandwiches" any intervening material like clot, coil,
atheroma and the like between the two walls 80, 82 of the aneurysm
72, taking advantage of the intervening material to close an
opening 84 into the aneurysm 72, eliminating blood flow into the
aneurysm 72 itself.
[0093] The unique design of the clip 10 with the arms 26, 28 or
clip blades, which are at rest in the closed position and not
sitting in the typical parallel opposition as is the case with
clips known from the prior art, diminishes or even eliminates the
dangerous tendency of traditional clips to slip down, thereby
occluding or narrowing a parent artery or branch artery, or
perforating the vessel 74, back off, remain perched in a precarious
partially open position, and/or fail to close. The clip 10 is
generally applied several millimeters above the true interface
between the parent artery 86 and the aneurysm 72 to avoid narrowing
the true parent artery. It is generally recommended that an
intraoperative angiogram be employed to assess the adequacy of
aneurysm obliteration and preservation of all critical
neurovascular structures, although this may be left at the
surgeon's discretion.
[0094] In select cases, when completely closing the aneurysm neck
78 is not safe or possible due to extreme calcification or atheroma
in the aneurysm walls 80, 82 or due to other unique consideration,
the clip 10 can be used to narrow the neck 78 of a wide-necked
aneurysm 72 allowing for more aggressive and possible curative
coiling. In the setting of very complicated aneurysms 72, the clip
10 can be used as a so-called "pilot" clip, to allow for partial
aneurysm closure, allowing for more aggressive dissection around
the aneurysm to be followed by more definitive clipping.
[0095] In summary, all current known aneurysm clip designs
incorporate preferably parallel blades that oppose each other at
rest to provide a closing force that brings together the generally
compliant walls 80, 82 of a simple brain aneurysm 72. In sharp
contrast, the so-called "compression clip" in the form of the
aneurysm clip 10 described above uses arms 26, 28 that are not
opposed at rest, sandwiching the walls 80, 82 against the
intervening material contained within the aneurysm 72 or within the
walls 80, 82 themselves to prevent blood from flowing into the
aneurysm 72. This completely novel design addresses the
difficulties that traditional clips face when attempting to close a
thick-walled aneurysm 72 with intraluminal clot, thrombus, or
coils. Instead of trying to force the aneurysm into a flat
"pancake-like" shape, the compression clip 10 takes advantage of
the natural curvature of the aneurysm wall 80, 82 as well as the
firm material within the aneurysm wall 80, 82 and within the
aneurysm 72. This intervening material becomes "part of the
solution" with the compression clip 10 as opposed to being "part of
the problem" with traditional clips.
[0096] The aneurysm clip 10 is preferably made from a biocompatible
material, in particular, a biocompatible metal such as titanium or
an implant steel.
[0097] A further embodiment of an aneurysm clip designated by the
overall reference numeral 110 is shown in FIG. 4. The clip 110 is
made from one piece and comprises clamping arms 126 and 128 which
extend parallel with respect to each other in a basic or clamping
position. A distance 160 between distal ends 132 of the arms 126,
128 is minimal in the clamping position.
[0098] Proximal end areas 188 and 190 adjoining the arms 126 and
128 are curved towards each other so that a first crossing portion
192 extending from the end area 190 penetrates a through-opening
118 in the form of a slit 120 in a second crossing portion 194
connected to the end area 188. End surfaces of the slit 120 facing
each other form stop surfaces 166, 168 of a stop device 164 which
defines both a maximum and a minimum distance 160 in a spread out
position and a compressed or closed position.
[0099] The crossing portions 192 and 194 are connected by means of
a restoring device 196 in the form of a coil spring 198 having
about 1.5 windings. A center of the spring coil 198 defines a pivot
axis 122 which extends perpendicular to a clamping plane defined by
the slit 120. The cross sections of the arms 126 and 128 are of
rectangular shape.
[0100] Clamping surfaces 134 and 136 of the arms 126, 128 carry
first and second clamping elements 200, 202 which are of cuboidal
shape. A width 204 of the clamping elements 200 and 202 is about
five to ten times longer than a width of the arms 126, 128 parallel
to the pivot axis 122. A thickness 206 of the clamping elements
200, 202 corresponds to 50% of the distance 160 in the closed or
basic position of the clip 110. This results in a direct contact of
the substantially planar clamping element surfaces 208 and 210 of
the clamping elements 200 and 202 facing each other. The clamping
elements 200 and 202 are designed in the form of pads made from a
preferably flexible or elastic material as, for example, a plastic
or a gel.
[0101] The method for treating the aneurysm 72 with the clip 110
corresponds to the method described above in connection with the
clip 10. The clamping elements 200 and 202 perfectly fit the neck
78 of the aneurysm 72 although the arms 126, 128 are not curved.
The flexible and/or elastic pads forming the clamping elements 200
and 202 automatically adapt to the negative form of the aneurysm 72
with the same result as the application of the aneurysm clip 10 as
outlined above.
[0102] In the closed position of the clip 110 the clamping elements
200 and 202 rest against each other with their clamping element
surfaces 208 and 210, preferably with a minimal closing force
applied to them. When the clip 110 is placed around the neck 78 of
the aneurysm 72 the clamping elements 200 and 202, preferably in
the form of gel pads enclose the aneurysm neck 78 and contour the
form of the intervening material 212 inside the aneurysm 72. This
provides for a perfect closing of the aneurysm 72 with an equal
closing force at each point. In order to offer a certain closing
force the movement of the clip 110 is blocked at the slit 120 by
introducing a blocking element, not shown in the drawings, into the
slit 120 in order to force the crossing portion 192 against one of
the stop surfaces 166 and 168.
[0103] A further embodiment of an aneurysm clip is designated by
the overall reference numeral 110' and shown schematically in FIGS.
5 and 6. The clip 110' is also made from one piece. However, in
contrast to the arms 126 and 128 of the clip 110 the arms 126' and
128' are concavely curved with respect to each other like the arms
126 and 128 of the clip 10 are. Clamping surfaces 134' and 136' of
the arms 126' and 128' may be structured in order to enhance a
gripping action thereof. Moreover, the arms 126' and 128' do not
carry clamping elements as the arms 126 and 128 do.
[0104] Other parts and portions of the clip 110' which are similar
or identical in their design to parts and portions of the clip 110
are designated in the figures by identical reference numerals
supplemented by a prime.
[0105] The application method for the clip 110' corresponds to the
application method as described above in connection with clips 10
and 110.
[0106] The primary unique feature of the clip 110' is that in its
closed position the arms 126' and 128' do not rest in a parallel,
perfectly opposed fashion. Rather, in the resting/closed position
of the clip 110' the arms 126' and 128' are separated by a preset
"opening distance" (O.D.) which corresponds to distance 160'.
Moreover, the arms 126' and 128' may be gently bowed inward, i.e.
concavely towards each other to match the rounded shape of most
intercranial aneurysms 72. Thus, in the closed positions, the
blades or arms 126' and 128' do not actually contact each other and
may not be parallel to one another. It has been noted that, because
the arms 126', 128' never contact each other, there is no
traditional measurement of a so-called "closing force" associated
with this clip design. Rather, the amount of pressure applied to
the aneurysm walls 80, 82 will depend on the amount of intervening
tissue/material 212 as well as the thickness and consistency of the
walls 80, 82 themselves. In order to offer a certain closing force
the movement of the clip parts 112' and 114' may be blocked at the
through-opening 118' with a spring tension remaining between the
arms 126' and 128'.
[0107] The clips 110 and 110' are also made from a biocompatible
material which enable leaving the clips 110 and 110' inside a
patient's body.
[0108] All the above-described clip designs allow closing of an
aneurysm 72 with intervening material, for example, coils, thrombus
or calcification in its neck area without the risk of closing the
supporting artery 86 partially or completely. The closing of the
aneurysm 72 is achieved using the above-described different
embodiments of the invention in the form of clips 10, 110 and 110'
which have in common that their arms are not totally closed in the
respective clamping positions. All the described clips leave the
intervening material inside the aneurysm 72 and offer a surgeon the
opportunity to leave the aneurysm 72 intact. Furthermore, it is not
necessary to temporarily clip the supporting artery 86 with the
risk of inducing small ischemic areas which are supported by small
vessels branching off from the temporarily clipped artery 86.
* * * * *