U.S. patent application number 13/558740 was filed with the patent office on 2013-12-19 for stent for bifurcation, a system for intravascular implantation of the stent for bifurcation and a method of implantation of the stent for bifurcation.
The applicant listed for this patent is Leszek HURKALA, Emil PLOWIECKI. Invention is credited to Leszek HURKALA, Emil PLOWIECKI.
Application Number | 20130338761 13/558740 |
Document ID | / |
Family ID | 49756601 |
Filed Date | 2013-12-19 |
United States Patent
Application |
20130338761 |
Kind Code |
A1 |
PLOWIECKI; Emil ; et
al. |
December 19, 2013 |
STENT FOR BIFURCATION, A SYSTEM FOR INTRAVASCULAR IMPLANTATION OF
THE STENT FOR BIFURCATION AND A METHOD OF IMPLANTATION OF THE STENT
FOR BIFURCATION
Abstract
A stent for bifurcation, including two cylindrical parts: a
distal part (1.1) of smaller diameter and a proximal part (1.2) of
greater diameter, connected by two--arranged as
opposite--longitudinal connectors (1.3) having length (L1) of 0.5
to 8 mm and forming a cell of the stent having an enlarged surface
area (1.4), the connectors having a curvilinear shape, in
particular a sinusoidal shape.
Inventors: |
PLOWIECKI; Emil; (Warsaw,
PL) ; HURKALA; Leszek; (Warsaw, PL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
PLOWIECKI; Emil
HURKALA; Leszek |
Warsaw
Warsaw |
|
PL
PL |
|
|
Family ID: |
49756601 |
Appl. No.: |
13/558740 |
Filed: |
July 26, 2012 |
Current U.S.
Class: |
623/1.35 |
Current CPC
Class: |
A61F 2/856 20130101;
A61F 2002/061 20130101; A61F 2/958 20130101; A61F 2002/91575
20130101; A61F 2002/91541 20130101; A61F 2002/828 20130101; A61F
2250/0039 20130101; A61F 2250/0098 20130101; A61F 2/915 20130101;
A61F 2/954 20130101 |
Class at
Publication: |
623/1.35 |
International
Class: |
A61F 2/82 20060101
A61F002/82 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 19, 2012 |
PL |
P.399580 |
Claims
1. A stent for bifurcation, comprising two cylindrical parts: a
distal part of smaller diameter and a proximal part of greater
diameter, connected by two longitudinal connectors, arranged as
opposite, having a length of 0.5 to 8 mm and forming a cell of the
stent having an enlarged surface area, wherein the connectors have
a curvilinear shape, in particular a sinusoidal shape.
2. A stent of claim 1, wherein a ratio of the distal part diameter
to the proximal part diameter of the stent is within the limits of
1.0:1.1 to 1.0:2.0.
3. A system for intravascular implantation of the stent for
bifurcation, comprising: a proximal part and a distal part
including an external tube, an internal tube and a profiled
balloon, wherein in the distal part of the system, on the internal
tube marked with three marker bands, visible at X-rays, there is
the profiled balloon fastened with a proximal part to the external
surface of the external tube and with a distal part--to the
external surface of the internal tube; and the stent for
bifurcation of claim 1 is clamped on the profiled balloon in a
detachable way, the profiled balloon including three non-separable
parts--the distal part, of smaller diameter, the proximal part, of
greater diameter, and a medial part having length from 0.5 to 8 mm,
located between the distal part and the proximal part, position of
the marker band coinciding with the proximal edge of the distal
part of the stent clamped on the balloon.
4. A system of claim 3, wherein a ratio of the distal part diameter
to the proximal part diameter of the profiled balloon is within the
limits of 1.0: 1.1 to 1.0: 2.0.
5. A system of claim 3, wherein between long edges of the distal
part of the profiled balloon and an edge of the medial part of the
profiled balloon there is an angle .theta. that lies within the
limits of 15.degree. to 65.degree..
6. A system of claim 3, wherein upon clamping the stent for
bifurcation in a separable way on the profiled balloon, the cell
having an enlarged surface area of the stent for bifurcation,
coincides with the medial part of the profiled balloon.
7. A method of introducing and positioning the stent for
bifurcation by means of the intravascular system including such the
stent, wherein the guide wire is introduced to the main branch of
the vessel at bifurcation site, upon which at bifurcation site, the
system defined in claim 3 including the stent defined in claim 1 is
introduced, the marker band visible at X-rays signaling the
position of edges of the proximal distal part of the stent clamped
on the balloon being positioned precisely at a site, where a carina
tip of the vessel is situated, so that the distal part of the stent
is situated behind a fork of the artery, in the main branch, the
proximal part of the stent is situated before the fork of an
artery, and the medial part of the stent, with the cell of the
stent having a special, enlarged surface area, being positioned in
a lumen of the side branch of the vessel, and then fluid under
pressure of 6 to 20 atm is introduced to the balloon, the stent is
implanted, the fluid is removed from the balloon and the system and
the guide wire are withdrawn.
Description
[0001] Object of the invention is a stent for bifurcation and a
system for intravascular implantation of the stent for
bifurcation.
[0002] The state-of-the art systems for intravascular implantation
of stents for bifurcation, utilizing various structural solutions
at implantation of the stent often marker band about injuries,
especially at ramifications of arteries. The most frequent problems
at implantation of the stent for bifurcation include partial or
complete closure of a side branch of arteries, contraction of side
branch of artery, dissection at bifurcation of vessels, a decrease
in a cross section of a side branch of artery as a result of marker
band of lumen with struts of an implanted stent, and occurrence of
thrombosis foci.
[0003] To avoid such situations, at present either one stent per
each branch is implanted while using separate systems for
intravascular implantation for each of the implanted stents or one
forked stent, mounted on the complicated system, is implanted.
[0004] Operations of intravascular implantation of stents for
bifurcation using state-of-the-art methods are extremely
complicated to implement and burdened with very high probability of
various post-operational complications in arteries with stents.
They must be carried out in surgeries provided with very modern
equipment. Furthermore, operators carrying out the implantation are
required to have high skills and much experience.
[0005] Accordingly, there is a demand for new, more effective
structural solutions for stent for bifurcation and systems for
intravascular implantation of such stents, in order to facilitate
implantation at a bifurcation site even by less experienced
operators and to provide higher safety and efficacy of
operation.
[0006] Aim of the present invention, is to increase efficacy and to
facilitate implantation procedure, thus increasing safety of
operation and promoting more wide use of stents and developing more
universal construction of stent extendable on a balloon, which
allows its implantation in vessels having different shapes and
sizes and of different mutual arrangement of a branch with respect
to the main vessel.
[0007] From international application WO0174273A1 a self-expanding
stent made of materials, such as e.g. nickel and titanium alloys,
consisting of two segments--proximal and distal is known, one of
them having greater diameter, and the segments being connected by
at least one longitudinal connector. That connector (or several
connectors located close to each other) is rectilinear and is
located only at one side of the stent, so that at the other side
between two segments of the stent a free space is formed. The
connector of the stent upon implanting in blood vessel adheres to
an internal wall of the vessel and it bends in such a way that
segments of the stent change their mutual position (there is an
angle between them), and free space between them is freely
increased.
[0008] A stent for bifurcation of the invention, consists of two
cylindrical parts: a distal part of smaller diameter and a proximal
part of greater diameter, connected by two--arranged as
opposite--longitudinal connectors having length of 0.5 to 8 mm,
that form a cell of the stent having an enlarged surface area, the
connectors having a curvilinear shape, in particular a sinusoidal
shape.
[0009] Preferably, a ratio of the distal part diameter to the
proximal part diameter of the stent is within the limits of 1.0:1.1
to 1.0:2.0.
[0010] A system for intravascular implantation of the stent for
bifurcation, consisting of the proximal part and the distal part
including an external tube, an internal tube, and a profiled
balloon, according to the invention, is characterized in that--in
the distal part of the system--on the internal tube marked with
three marker bands, visible at X-rays, there is a profiled balloon
fastened with the proximal part to the external surface of the
external tube and with the distal part--to the external surface of
the internal tube, and on the profiled balloon, a stent for
bifurcation defined in claim 1, as presented above, is clamped in a
detachable way, the profiled balloon consisting of three
non-separable parts--a distal part, of smaller diameter, a proximal
part, of greater diameter, and a medial part having length of 0.5
to 8 mm located between the distal part and the proximal part,
position of the medial marker band coinciding with the proximal
edge of the distal part of the stent clamped on the balloon.
[0011] Preferably, a ratio of the distal part diameter to the
proximal part diameter of the profiled balloon is within the limits
of 1.0: 1.1 to 1.0: 2.0.
[0012] Between the long edges of the distal part of the profiled
balloon and the edge of the medial part of the profiled balloon
there is an angle .theta. that lies within the limits of 15.degree.
to 65.degree..
[0013] Upon clamping the stent for bifurcation on the profiled
balloon in a separable way, a cell having an enlarged surface area
of the stent for bifurcation, coincides with the medial part of the
profiled balloon.
[0014] Method of introducing and positioning the stent for
bifurcation by means of an intravascular system including the stent
of the invention, is characterized in that a guide wire is
introduced to a main branch of a vessel at bifurcation site, after
which, a system defined in claim 3, as presented above, is
introduced into the bifurcation site, including the stent defined
in claim 1, as presented above, a medial marker band visible at
X-rays signaling a position of the proximal edge of the distal part
of the stent clamped on the balloon being precisely positioned at a
site, where there is a groin of the vessel, such that the distal
part of the stent is situated behind a fork of the artery, in a
main branch, whereas the proximal part of the stent is situated
before the fork of the artery, and the medial part of the stent ,
with a cell of the stent having special, enlarged surface area, is
located in the lumen of the side branch of the vessel, and then
liquid under pressure from 6 to 20 atm is introduced to the
balloon, the stent is implanted, then, the fluid is removed from
the balloon and the system and the guide wire are withdrawn.
[0015] On the internal tube of the system for intravascular
implantation of the stent for bifurcation, three marker bands
visible at X-rays, are fastened, in such a way, that a first marker
band coincides with a beginning of long edges of the proximal part
of the profiled balloon, a second marker band coincides with a
beginning of long edges of the distal part of the profiled balloon,
whereas a third marker band coincides with an ending of long edges
of the distal part of the profiled balloon.
[0016] The stent for bifurcation is suitably clamped in a
detachable way on the profiled balloon.
[0017] The stent for bifurcation and the system for its
implantation in an embodiment example is shown on a drawing, in
which FIG. 1 shows a view of the stent for bifurcation with a
visible cell of the stent having enlarged surface area, in FIG. 2
the balloon constituting an element of the system for stent
implantation is shown, in FIG. 3--a view of the distal part of the
system for intravascular implantation of the stent for bifurcation
and its location in a branch of artery, being a site of
implantation of the stent is shown, in FIG. 4 the stent located in
the vessel at its bifurcation site upon withdrawal of the system,
and in FIGS. 5A, 5B, 5C--as a matter of example--positions of the
distal part and the proximal of the stent upon its positioning in
the vessel are shown.
[0018] A special, profiled structure of the stent for bifurcation
allows such positioning of the system for intravascular
implantation of the stent for bifurcation during implantation of
the stent for bifurcation that the distal part of the stent is
positioned behind the fork of the vessel, in a more narrow part of
the vessel, the proximal part of the stent for bifurcation is
positioned before the fork of the vessel, and the medial part of
the stent, with connectors of the stent, forming at the same time
the cell of the stent having special, enlarged surface area, being
positioned precisely in a lumen of the side branch, thereby
preventing from blocking blood flow through the side branch of the
artery.
[0019] Two opposite connectors assure that both parts of the stent
are kept at a suitable distance from each other, but at the same
time the connectors allow, within a defined range, free adjusting
to an anatomical shape of vessels. Both parts of the stent upon
implantation are supported in an uniform way by the two connectors
located symmetrically on two sides of the stent.
[0020] Connectors are located longitudinally with respect to the
stent and are curved e.g. have a sinusoidal shape, a wavy shape, a
shape of letter "S" or a double "S" shape or an accordion shape or
are slightly twisted, like an extended fragment of a helix. Such
shapes of connectors cause that--depending on a structure of the
vessel, where the stent will be implanted--they may be easily
expanded or clamped, so that a primary distance between the
proximal part and the distal part of the stent will be increased or
decreased. A distance between the parts of the stent upon its
implanting at the side of the first connector and at the side of
the second connector may be different, as it is shown in FIGS. 5B
and 5C. In that case, the parts of the stent are positioned to each
other in such a way that there is an angle between them. The
connectors also make it possible to carry out a slight shift of the
proximal part and the distal part of the stent with respect to the
longitudinal axis of the stent. Primarily both parts of the stent
are arranged in such a way that their symmetry axes overlap, as it
is shown in FIG. 1. No matter how parts of the stent will be
arranged with respect to each other upon implanting, the two
opposite connectors limit freedom of movement of the stent at its
implantation and do not enable unrestricted movement of the distal
part and the proximal part of the stent.
[0021] Location of a system of three marker bands well visible at
X-rays on the internal tube provides precise positioning and
visibility of the stent for bifurcation during its implantation in
vessels. The stent for bifurcation is tightened in a separable way
on the profiled balloon in such a way that a cell having an
enlarged surface area of the stent for bifurcation coincides with
the medial part of the profiled balloon. Marker 7 coincides with
the proximal edge of the distal part of the stent clamped on the
balloon, and during implantation of the stent, marker 7 must
coincide in the vessel with a beginning of the carina tip of the
vessel. A specific shape of the profiled balloon prevents from
shifting the carina tip of the vessel during implantation of the
stent for bifurcation, thus preventing from blocking blood flow
through the side branch of the artery.
[0022] The stent expandable on the balloon of the invention is
entirely made of typical, known materials used for such purposes,
preferably of stainless steel 316L or alloy L605.
[0023] The stent for bifurcation 1 of the invention, consists of
two cylindrical segments--of the distal part, of smaller diameter
1.1 and of the proximal part, of greater diameter 1.2, connected by
two connectors 1.3 having length L1, forming the cell of the stent
having an enlarged surface area 1.4. The distal part of the stent
may be longer or shorter than the proximal part of the stent. Both
parts of the stent may also be approximately equal to each other.
Prior to implantation both parts of the stent are positioned
coaxially. The connectors, with which the stent is equipped, are
arranged as opposite--i.e. on a circumference of the stent they are
located 180.degree. apart. A distance between the proximal part and
the distal part of the stent may have length from 0.5 to 8 mm, e.g.
from 0.5 to 3 mm or from 2 to 4 mm, or from 3 to 8 mm. Preferably
both connectors have equal length. Preferably connectors are not
rectilinear but are of a curved shape, e.g. a sinusoidal shape.
[0024] The system for intravascular implantation of the stent for
bifurcation of the invention in its distal part consists of the
profiled balloon 2 fastened to the system in that way that the
proximal part 2.2 of the profiled balloon 2 is fastened to the
external surface of the external tube 4 of the system, and the
distal part 2.1 of the profiled balloon 2 is fastened to the
external surface of the internal tube 5 of the system.
[0025] The profiled balloon 2 consists of three non-separable
parts: the distal part, of smaller diameter 2.1, the proximal part,
of greater diameter 2.2, and the medial part 2.3 of a defined
length, located between the distal part 2.1 and the proximal part
2.2. The distal part of the balloon may be longer or shorter than
the proximal part of the balloon. Both parts of the balloon may
also be approximately equal. The medial part of the balloon is
adjusted to a distance between the distal part and the proximal
part of the stent and may have length from 0.5 to 8 mm, for example
from 0.5 to 3 mm or from 2 to 4 mm, or from 3 to 8 mm.
[0026] Between long edges of the distal part 2.1 and an edge of the
medial part 2.3 of the profiled balloon 2 there is an angle
.THETA.. The stent for bifurcation 1 is clamped in a separable way
on the profiled balloon 2 in such a way that the cell of the stent
having an enlarged surface area 1.4 of the stent for bifurcation 1
coincides with the medial part 2.3 of the profiled balloon 2, the
distal part of the stent 1.1 is mounted on the distal part of the
balloon 2.1 and the proximal part of the stent 1.2 is mounted on
the proximal part of the balloon 2.2.
[0027] On the internal tube 5 of the system for intravascular
implantation of the stent for bifurcation at least one marker band
7 is fastened, preferably three marker bands 6, 7, 8, visible at
X-rays, in such a way, that the marker band 6 coincides with a
beginning of long edges of the proximal part 2.2 of the profiled
balloon 2, the marker band 7 coincides with a beginning of long
edges of the distal part 2.1 of the profiled balloon 2, and the
marker band 8 coincides with an ending of long edges of the distal
part 2.1 of the profiled balloon 2. The stent is tightened in a
separable way on the balloon of the system in such a way that the
marker band 6 coincides with the proximal edge of the stent 1, the
marker band 8 coincides with the distal edge of the stent 1, and
the marker band 7 coincides with the proximal edge of the distal
part 1.1 of the stent, in other words the marker band 7 coincides
with that edge of the distal part of the stent, which is situated
at the side of the cell of the stent having an enlarged surface
area 1.4.
[0028] The system for intravascular implantation of the stent of
the invention is introduced into body in that way, that the guide
wire P2 is delivered to the bifurcation site that is positioned in
the main branch of the artery.
[0029] Then, the system for intravascular implantation of a stent
of the invention is introduced on the guide wire P2.
[0030] The internal tube 5 of the system for intravascular
implantation of the stent is put onto the guide wire P2.
[0031] Then, while shifting the entire system for intravascular
implantation of the stent on the guide wire P2, controlling at the
same time position of the three marker bands 6, 7, 8 by X-rays, the
stent for bifurcation 1 with the profiled balloon 2 is very
precisely positioned at the bifurcation site: the system is
introduced on the guide wire P2 into the main branch of the artery,
so that the marker band 7 would be at the same height, where the
carina tip of the vessel is situated. By means of control of
position of the marker 7 it is possible to position proximal edges
of the distal part of the stent 1 precisely in one line with the
carina tip of the vessel.
[0032] Such introduction of the system for intravascular
implantation of the stent for bifurcation results in that the
distal part 1.1 of the stent for bifurcation is situated behind the
fork of the artery, in the main branch, the proximal part 1.2 of
the stent for bifurcation is situated before the fork of the
artery, and the medial part of the stent, with the cell of the
stent having a special, enlarged surface area 1.4, is positioned in
a lumen of the side branch.
[0033] Then, a fluid under pressure of 6 to 20 atm is introduced to
the profiled balloon 2, which causes expanding of the profiled
balloon 2, thus opening the stent for bifurcation 1. The open stent
for bifurcation 1 widens lumen of the vessel, thus eliminating
contraction.
[0034] Upon total opening of the stent for bifurcation 1, its
medial part, with the cell of the stent having a special, enlarged
surface area 1.4, is positioned precisely in a lumen of the side
branch, which allows free blood flow through the side branch of the
artery.
[0035] Then, the fluid is removed from the profiled balloon 2, the
whole system with the empty profiled balloon 2 is withdrawn from
blood circulation system. At the end, the guide wire P2 is
withdrawn. The open stent for bifurcation 1 remains at the site,
where there was contraction of the artery, thus causing its
permanent widening.
* * * * *