U.S. patent application number 09/730974 was filed with the patent office on 2001-11-08 for endoprosthesis for the treatment of blood-vessel bifurcation stenosis and purpose-built installation device.
Invention is credited to Dibie, Alain.
Application Number | 20010039448 09/730974 |
Document ID | / |
Family ID | 9478696 |
Filed Date | 2001-11-08 |
United States Patent
Application |
20010039448 |
Kind Code |
A1 |
Dibie, Alain |
November 8, 2001 |
Endoprosthesis for the treatment of blood-vessel bifurcation
stenosis and purpose-built installation device
Abstract
An endoprosthesis for the treatment of blood-vessel bifurcation
stenosis. The endoprosthesis comprises three tubular sections and
two connectors. A first distal section is aligned at least
approximately with a proximal section. The first distal section is
intended for insertion into a first blood vessel branching off on
the bifurcation. The first distal section is linked to the proximal
section by a first lateral connector. A second distal section,
located at the side of the first distal section is intended for
insertion into a second vessel branching off from the bifurcation.
The two distal sections have their proximal ends linked by a second
connector.
Inventors: |
Dibie, Alain; (Paris,
FR) |
Correspondence
Address: |
Blakely, Sokoloff, Taylor & Zafman LLP
7th Floor
12400 Wilshire Boulevard
Los Angeles
CA
90025-1026
US
|
Family ID: |
9478696 |
Appl. No.: |
09/730974 |
Filed: |
December 4, 2000 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09730974 |
Dec 4, 2000 |
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08945973 |
Jan 26, 1998 |
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6183509 |
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Current U.S.
Class: |
623/1.16 ;
623/1.11 |
Current CPC
Class: |
A61F 2002/91558
20130101; A61F 2002/91541 20130101; A61F 2/91 20130101; A61F 2/856
20130101; A61F 2/958 20130101; A61F 2250/006 20130101; A61F 2/07
20130101; A61F 2002/065 20130101; A61F 2/915 20130101; A61F 2/954
20130101 |
Class at
Publication: |
623/1.16 ;
623/1.11 |
International
Class: |
A61F 002/06 |
Foreign Application Data
Date |
Code |
Application Number |
May 4, 1995 |
FR |
95 05334 |
Claims
I claim: ?
27. An endoprosthesis for the treatment of blood-vessel bifurcation
stenosis, comprising three tubular sections and two articulation
connectors namely: a proximal section; a first distal section
aligned at least approximately with the proximal section and
intended for insertion into a first blood vessel branching off from
the bifurcation, the distal section being linked to the proximal
section by a lateral connector; and a second distal section located
at the side of the first distal section and intended for insertion
into a second blood vessel branching off from the bifurcation, both
distal sections having their proximal ends linked by a second
connector which allows relative pivoting of said distal sections
about said connector to accommodate the blood-vessel bifurcation,
wherein the three tubular sections are of identical diameter prior
to use.
28. An endoprosthesis according to claim 27, wherein the distal end
of the proximal section is chamfered and the proximal end of the
second distal section is tapered at the other side of the second
connector and able to fit into the chamfered form of the proximal
section.
29. An endoprosthesis according to claim 27, wherein the chamfer
form is delimited by a flat surface.
30. An endoprosthesis according to claim 27, wherein the tapered
section is delimited by a flat surface.
31. An endoprosthesis according to claim 27, wherein the chamfer
form is delimited by a curved surface.
32. An endoprosthesis according to claim 27, wherein the tapered
section is delimited by a curved surface.
33. An endoprosthesis according to claim 27, wherein the first
connector has at its centre a plane of symmetry determined by the
axes of the tubular sections and extends in a direction that is
approximately parallel to these axes.
34. An endoprosthesis according to claim 27, wherein the first
connector is formed from the same part as the proximal section and
the first distal section.
35. An endoprosthesis according to claim 27, wherein the second
connector has as its centre a plane of symmetry determined by the
axes of the tubular sections and extends in a direction
approximately perpendicular to these axes.
36. An endoprosthesis according to claim 27, wherein the second
connector is attached to the two distal sections.
37. An endoprosthesis according to claim 27, wherein each of the
sections (110, 120 and 140) is formed from a tubular component with
a grid pattern of slits susceptible of expansion
circumferentially.
38. An endoprosthesis for the treatment of blood-vessel bifurcation
stenosis, comprising three tubular sections and two articulation
connectors namely: a proximal section; a first distal section
aligned at least approximately with the proximal section and
intended for insertion into a first blood vessel branching off from
the bifurcation, the distal section being linked to the proximal
section by a lateral connector; and a second distal section located
at the side of the first distal section and intended for insertion
into a second blood vessel branching off from the bifurcation, both
distal sections having their proximal ends linked by a second
connector which allows relative pivotment of said distal sections
about said second connector to accommodate the blood-vessel
bifurcation wherein the second connector has at its centre a plane
of symmetry determined by the axes of the tubular sections and
extends in a direction approximately perpendicular to these
axes.
39. An endoprosthesis according to claim 38, wherein the distal end
of the proximal section is chamfered and the proximal end of the
second distal section is tapered at the other side of the second
connector and able to fit into the chamfered form of the proximal
section.
40. An endoprosthesis according to claim 38, wherein the chamfer
form is delimited by a flat surface.
41. An endoprosthesis according to claim 38, wherein the tapered
section is delimited by a flat surface.
42. An endoprosthesis according to claim 38, wherein the chamfer
form is delimited by a curved surface.
43. An endoprosthesis according to claim 38, wherein the tapered
section is delimited by a curved surface.
44. An endoprosthesis according to claim 38, wherein the three
tubular sections are of identical diameter prior to use.
45. An endoprosthesis according to claim 38, wherein the first
connector has at its centre a plane of symmetry determined by the
axes of the tubular sections and extends in a direction that is
approximately parallel to these axes.
46. An endoprosthesis according to claim 38, wherein the first
connector is formed from the same part as the proximal section and
the first distal section.
47. An endoprosthesis according to claim 38, wherein the second
connector is attached to the two distal sections.
48. An endoprosthesis according to claim 38, wherein each of the
sections is formed from a tubular component with a grid pattern of
slits susceptible of expansion circumferentially.
Description
[0001] This invention relates to the field of endoprostheses for
the treatment of blood-vessel bifurcation stenosis.
[0002] This invention also relates to a purpose-built installation
device.
[0003] It has already been suggested that stenosis found in
coronary arteries be treated using endoprostheses formed from
tubular structures perforated with a grid pattern of slits and
consequently expandable following placement at the site of
stenosis. In most cases these endoprostheses are expanded by
inflating a balloon which is placed inside them and subsequently
withdrawn.
[0004] Generally speaking, endoprostheses of this type may be said
to have already given good service.
[0005] They are not, however, fully satisfactory.
[0006] The applicant has, in particular, observed that standard
endoprostheses are not fully satisfactory when, as is frequently
the case, there is stenosis at a blood-vessel bifurcation. In such
cases, treatment using standard endoprostheses requires two
separate endoprostheses. One of these is placed in each of the two
vessels branching off from the bifurcation and their positioning in
relation to each other is adjusted as finely as possible to ensure
optimal cover of the bifurcation area.
[0007] A primary goal of this invention is to develop existing
endoprostheses in order to facilitate and improve treatment of
blood-vessel bifurcation stenosis.
[0008] This goal is attained by this invention through the use of
an endoprosthesis comprising three tubular sections and two
connectors, namely:
[0009] a proximal section;
[0010] a first distal section aligned at least approximately with
the proximal section and intended for insertion into one of the
vessels branching off from the bifurcation, this distal section
being attached to the proximal section by means of a laterally
positioned connector; and
[0011] a second distal section placed at the side of the first
distal section and intended for insertion into the second vessel
branching off from the bifurcation, the two distal sections having
their proximal ends joined by the second connector.
[0012] In accordance with another advantageous feature of this
invention, the distal end of the proximal section is chamfered and
the proximal end of the second distal section is tapered at the
other side of the second connector and fits into the chamfer in the
proximal section.
[0013] The above-mentioned chamfered shapes and tapered ends may
have a variety of embodiments. They may, in particular, be
delimited by flat or curved surfaces.
[0014] Another important goal of this invention is to perfect the
method of installing the above-mentioned endoprostheses.
[0015] According to this invention this goal is attained by using a
double-balloon system, as follows:
[0016] a first balloon of suitable length for insertion into two
approximately aligned sections of the blood vessel to be treated:
the main stem and the first branching blood vessel, on either side
of the bifurcation area respectively; and
[0017] a second balloon of suitable nature for insertion into the
second blood vessel branching off from the bifurcation.
[0018] In accordance with another advantageous feature of the
invention, the first balloon incorporates a lateral recess to be
positioned facing the bifurcation area with a view to housing the
proximal end of the second balloon.
[0019] In accordance with another advantageous feature of this
invention, the distal portion of the first balloon located
downstream of the recess is of smaller diameter than the proximal
portion of the balloon located upstream of the recess.
[0020] Further features, goals and advantages of the invention will
be apparent on reading the following detailed description as
illustrated in the corresponding accompanying drawings, which are
given as non-exhaustive examples and in which:
[0021] FIG. 1 is a schematic side view of an endoprosthesis in
accordance with this invention;
[0022] FIG. 2 is a perspective view of the same endoprosthesis;
[0023] FIG. 3 is another perspective view of the same
endoprosthesis after relative inclination of the distal
sections;
[0024] FIG. 4 is a view of the same endoprosthesis following
expansion of the various tubular sections from which it is
formed;
[0025] FIG. 5 is a schematic illustration of an endoprosthesis
combined with the device for installing it, prior to implantation
in a stenosis-affected bifurcation area;
[0026] FIG. 6 is a view of the same instrument following
implantation in a bifurcation and expansion of the proximal section
and one distal section;
[0027] FIG. 7 is a view of the same endoprosthesis after expansion
of the three sections from which it is formed;
[0028] FIG. 8 is a schematic side view of the first balloon in
accordance with the invention;
[0029] FIG. 9 is a side view of the second balloon in accordance
with the invention;
[0030] FIG. 10 is an overall view of an installation instrument
comprising two balloons working together in accordance with the
invention;
[0031] FIG. 11 is another side view of the balloon-based
installation system in accordance with the invention;
[0032] FIG. 12 is an overall view of the same balloon-based
installation tool combined with means of inflation; and
[0033] FIG. 13 is a schematic cross-sectional view of a feeder tube
for the double-balloon system.
[0034] The first item described will be the structure of
endoprosthesis 100 in accordance with the invention and illustrated
in FIGS. 1 to 7. As was mentioned earlier, endoprosthesis 100
comprises three tubular sections (110, 120 and 140) and two
connectors (130 and 150).
[0035] The first section (110) is a proximal section having as its
centre axis 111. It is intended for insertion into main stem T1 of
blood vessel V for treatment, upstream of the bifurcation.
[0036] The first distal section (120) having as its section axis
121 is at least approximately aligned with proximal section 110
prior to use. This first distal section 120 is intended for
insertion into blood vessel T2 branching off from the bifurcation
as is seen in particular in FIGS. 6 and 7.
[0037] The first distal section (120) is attached to proximal
section 10 by the first lateral connector (130).
[0038] The second distal section (140), having as its axis 141, is
positioned at the side of the first distal section (120), and has
the advantage of being parallel to the latter, prior to use. The
second distal section (140) is intended to be inserted into blood
vessel T3 branching off from the bifurcation, as is seen in
particular in FIGS. 6 and 7.
[0039] The two distal sections 120 and 140 have their proximal ends
(122 and 142) linked by the second connector (150).
[0040] Each of section 110, 120 and 140 is preferably formed from a
tubular component perforated with a grid pattern of slits such that
the structure of sections 110, 120 and 140 allows them to expand
along their circumferences.
[0041] In practice, section 110, 120 and 140 of endoprosthesis 100
can be manufactured from extruded cylindrical parts made of a
bendable metal alloy such as 316L stainless steel. The external
diameter of section of 110, 120 and 140 typically ranges from 1 to
1.2 mm prior to use.
[0042] There can be a range of variants of the grid pattern cut
into sections 110, 120 and 140. The opening may take the form of a
hexagon or diamond, as shown in the accompanying figures, taking on
the appearance of grating following expansion against the inner
surface of the coronary artery by means of a cylindrical balloon
placed inside.
[0043] As the basic structure of expandable tubular components 110,
120 and 140 and the material from which they are made are familiar
to those skilled in the art, these particulars will not be
described in detail in what follows.
[0044] The three sections 110, 120 and 140 are preferably of equal
diameter prior to expansion, i.e. prior to use.
[0045] The respective axes (111, 121 and 141) of sections 110, 120
and 140 are coplanar and determine a plane of symmetry for the
endoprosthesis. This plane of symmetry is parallel to the plane of
FIG. 1.
[0046] The first connector (130) has as its centre the
above-mentioned plane of symmetry determined by axes 111, 121 and
141.
[0047] Connector 130 links an area of distal end 113 of proximal
section 110 with an area of proximal end 122 of the first distal
section (120). Yet more specifically, articulation 130 preferably
consists of a strip of constant width parallel to axes 111 and 121.
Articulation 130 is diametrically opposite the second distal
section (140) with respect to axes 111 and 121.
[0048] Distal end 113 of proximal section 110 is provided with
chamfer 115 in its peripheral area situated opposite connector 130.
Chamfer 115 can be determined by a plane that is inclined with
respect to axis 111, perpendicular to the above-mentioned plane of
symmetry or, again, be curved, for instance, concave with respect
to distal section 120. Angular opening of the wall of proximal
section 110 thus increases starting from connector 130 and turns
through 360.degree., i.e. a complete tubular form around axis
111.
[0049] This cant (115) forms a type of arch located on the side
opposite connector 130 embodying in the cylindrical structure
forming proximal section 110 the shape of the ostium of the blood
vessel branching off from the coronary bifurcation onto which it
will be applied.
[0050] Furthermore, proximal end 142 of the second distal section
(140) is tapered at the other side of the second connector (150).
It stretches forwards in its peripheral area opposite the second
connector (150). This tapered portion (144) may also be determined
by a plane that is inclined with reference to axis 121,
perpendicular to the plane of symmetry or, again, by a curved
surface.
[0051] After expansion, as is illustrated in FIG. 4 for example,
when the endoprosthesis is installed at the bifurcation of the two
coronary arteries, distal portion 113 with the corner cut off (115)
of proximal section 110 is fixed together harmoniously with the
proximal (144) of section 140 of the endoprosthesis and ensures
maximum coverage of the dilated coronary bifurcation area.
[0052] In this way, once in place, the whole of the grid of the
bifurcated endoprosthesis (100) covers the proximal and distal
portions of the two coronary branching arteries and the whole of
the dilated bifurcation area.
[0053] The first connector (130) preferably forms an integral part
i.e. it is not joined onto sections 110 and 120.
[0054] In other words, the first connector (130) and sections 110
and 120 are preferably manufactured from a single part in which
connector 130 is formed via machining.
[0055] The second connector (150) is also centred with reference to
the plane of symmetry determined by axes 111, 121 and 141.
[0056] However, whereas the first connector (130) extends in a
direction that is parallel to axes 111 and 121, the second
connector (150) extends in a direction that is transversal to the
above-mentioned axes 111, 121 and 141 and links adjacent areas of
proximal ends 122 and 142 of distal sections 120 and 140.
[0057] The second connector (150) is preferably joined to proximal
ends 122 and 142 of sections 120 and 140 by means of, for example,
laser welding.
[0058] This aspect of the invention can, naturally, be embodied by
a range of variants in that the second connector (150) could form
an integral part with distal sections 120 and 140 formed from a
single part, while connector 130 would be joined by means of, for
example, laser welding to the distal end of proximal section 110
and the proximal end of distal section 120.
[0059] In accordance with a particular embodiment, given as a
non-exhaustive example, bifurcated endoprosthesis 100 for the
coronary artery conforming with this invention has the following
dimensions:
[0060] the total length of endoprosthesis 100 measured from
proximal end 112 of proxinmal section 110 to distal end 123 of
distal section 120 is of the order of 15 mm;
[0061] the diameter of sections 110, 120 and 140 is of the order of
1 mm prior to expansion;
[0062] the length of proximal section 110 is of the order of 7.5 mm
prior to expansion;
[0063] the length of distal section 120 is of the order of 7 mm
prior to expansion;
[0064] the length of distal section 140 is of the order of 9 mm
prior to expansion;
[0065] the length of connector 130 is of the order of 0.5 to 1 mm;
and
[0066] the diameter of distal sections 120 and 140 in their
expanded state is of the order of 3 mm while the diameter of
proximal section 110 is of the order of 3.5 mm.
[0067] A description now follows of the structure of the instrument
fitted with a double asymmetric balloon conforming with this
invention which is shown in FIG. 8 et seqq.
[0068] Essentially, this instrument (200) comprises two balloons
(210 and 230). The first balloon (210) is of a length consonant
with its purpose of being positioned inside two approximately
aligned sections (T1 and T2) of vessel V for treatment: main stem
T1 and a branching vessel T2, situated one on either side of the
bifurcation area respectively, or, again, of being positioned
inside proximal section 110 and distal section 120 of
endoprosthesis 100.
[0069] As regards the second balloon (230), this is consonant with
its purpose of being positioned in the second blood vessel (T3)
branching off from the bifurcation. Balloon 230 is preferably
shorter than balloon 210. As shown in the accompanying figures, the
two balloons 210 and 230 are preferably formed from generally
cylindrical elongated tubular items centred upon axes 212 and 232
and having their ends (214 and 216; 234 and 236) more or less
rounded.
[0070] The main balloon (210) preferably incorporates a recess in
its side (218) suitable for housing proximal end 236 of the second
balloon (230) as shown in FIG. 10.
[0071] Furthermore, proximal portion 219 of balloon 210 located
upstream of recess 218 is preferably of greater diameter than
distal portion 217 of the same balloon located downstream of recess
218.
[0072] Each of the balloons 210 and 230 is preferably fitted with a
radio-opaque tracer (220 and 240). Tracers 220 and 240 are
preferably located at the centres of their respective balloons 210
and 230. Tracers 220 and 240 may, for example, be carried by hollow
internal tubes 221 and 241 housing metallic guides 222 and 242
having as their centres axes 212 and 232 and passing axially
through balloons 210 and 230 respectively. Tracers 220 and 240 are
preferably located halfway along balloons 210 and 230.
[0073] Balloons 210 and 230 are prolonged a; their proximal ends
216 and 236 by, respectively, tubes 224 and 244, of narrow
cross-section, designed to feed and, consequently, dilate balloons
210 and 230.
[0074] Tubes 224 and 244 preferably house guides 222 and 242. More
specifically, each of the two tubes 224 and 244 preferably has two
lumina: the first lumen houses a guide (222 and 242) and opens into
the associated internal tube (221 and 241) and the second lumen,
used for inflating the balloons, opens into the inside surface of
the balloons (210 and 230).
[0075] The above-mentioned internal tubes 221 and 241 and first
lumina are not connected with the internal surface of balloons 210
and 230.
[0076] Furthermore, internal tube 221 inside the first balloon
(210) is preferably off-centre with respect to axis 212 in order to
allow for the presence of recess 218 as is seen in FIG. 8.
[0077] Inflation tubes 224 and 244 are joined at a certain distance
from balloons 210 and 230 and are preferably attached by their
proximal ends to a stiffer but both flexible and hollow common
component 250 with two internal lumina (253 and 254) linked with
inflation tubes 224 and 244 respectively or, more specifically, the
said above-mentioned second inflation lumina of these tubes.
Component 250 is, moreover, itself fitted at its proximal end (252)
with two connection systems with fluid sources linked with lumina
253 and 254 respectively, allowing balloons 210 and 230 to be
expanded. These connection systems may, for example, be of the type
known as "Luer-Lock". A variant on this is that the above-mentioned
connection systems may be adapted to take a standard inflation
syringe tip.
[0078] It is important that the above-mentioned connection systems
communicating with, respectively, lumina 253 and 254 formed inside
component 250 should allow the two balloons (210 and 230) to be
expanded separately.
[0079] Balloons 210 and 230 are preferably covered prior to use
with a removable sheath (260). Sheath 260 covers the fill length of
endoprosthesis 100, i.e. preferably a minimum of 15 to 20 mm.
Sheath 260 is preferably linked at its proximal end to a wire (262)
facilitating removal of sheath 260 by pulling the said wire 262.
Wire 262 preferably passes through common tube 250.
[0080] Sheath 260 can, however, be omitted when the balloon system
alone is used, i.e. without endoprosthesis 100.
[0081] The "Luer-Lock" connection systems shown in FIG. 12 are
referred to as 252. Furthermore, reference n.degree. 270 in FIG. 12
labels a schematic inflation system comprising a pressure gauge
(272) adapted for linkage to one of the connection system (252)
with a view to dilating one of balloons 210 and 230.
[0082] Reference n.degree. 253 and n.degree. 254 in FIG. 13 label
the two feeder lumina linking connection systems 252 with tubes 224
and 244 respectively. In addition, reference n.degree. 255 in FIG.
13 labels the lumen housing the wire (262) facilitating the removal
of sheath 260.
[0083] In accordance with a particular embodiment that is,
naturally, non-exhaustive, asymmetric double balloon 200 for
coronary angioplasty conforming with this invention has the
following dimensions:
[0084] guide-wires 222 and 242 are 0.036 cm (0.014 inch)
guide-wires;
[0085] the longer balloon (210) is 20 to 25 mm in length, depending
on the model;
[0086] its proximal portion (219) is approximately 3.5 mm in
diameter and approximately 6.5 mm in length after inflation;
[0087] recess 218 is approximately 3.5 mm in length;
[0088] distal portion 217 is approximately 10 mm in length and
approximately 3 mm in diameter after inflation;
[0089] the second balloon (230) is approximately 13 mm in length
and approximately 3 mm in diameter after inflation;
[0090] tubes 224 and 244 are joined approximately 10 mm from the
proximal end (216) of balloon 210;
[0091] the lengths of the two tubes 224 and 244 between the point
at which they join and common component 250 may range from
approximately 20 to 30 cm;
[0092] the overall length, including balloons 210 and 230 and their
feeder tubes is preferably approximately 135 mm;
[0093] the length of common tube 250 ranges from approximately 110
to 115 mm; and
[0094] the outer diameter of the device with balloons 210 and 230
completely deflated preferably does not exceed 2 mm, so that the
whole unit including the two balloons 210 and 230 and feeder tubes
224 and 244 may pass through an 8F guiding-catheter with an
internal diameter of 2.6 mm. The case is the same in the version of
the balloon device fitted with endoprosthesis 100 and sheath
260.
[0095] The portion of tubes 224 and 244 that is located downstream
of guide-wire exits 223 and 243 is preferably made of plastic.
[0096] The portion of tubes 224 and 244, including common portion
250, that is located upstream of exits 223 and 243 may be made of
plastic or metal.
[0097] This tube (224, 244 and 250) must be as hydrophilic as
possible in order to be able to slide inside its carrier catheter
or guiding catheter.
[0098] It should be noted that balloons 210 and 230 are mutually
independent. They are indirectly linked only in the area of common
tube 250.
[0099] Guide-wires 222 and 242 preferably emerge from tubes 224 and
244 on the nearer side of common section 250, as is seen in FIG.
11. Exit points 223 and 243 of guide-wires 222 and 242 are
preferably at a slight distance from each other and are marked
differently for identification.
[0100] A description now follows of the process for installing
endoprosthesis 100 using asymmetric double balloon 200 in
accordance with this invention.
[0101] Prior to use, the unit combining the two balloons (210 and
230) and bifurcated endoprosthesis 100 is protected by covering
sheath 260. This unit fitted with sheath 260 is firstly manoeuvred
close to the bifurcation stenosis area. Its position is monitored
using radio-opaque tracers 220 and 240.
[0102] Once the balloon (210 and 230)/endoprosthesis (100) unit has
arrived at the bifurcation, above-mentioned sheath 260 can be
withdrawn by pulling wire 262.
[0103] After protective sheath 260 has been withdrawn, guide-wires
222 and 242, which have been inserted into blood vessels T2 and T3
branching off from the coronary bifurcation, are manipulated.
Balloons 210 and 230, located respectively inside proximal section
110 and distal section 120 in the case of balloon 210 and inside
distal section 140 in the case of balloon 230, are still in a
deflated state at this stage. Once it has been ascertained that
sections 120 and 140 of the endoprosthesis have been correctly
positioned at the bifurcation using radio-opaque tracers 220 and
240 contained in the balloons, the balloons can be inflated.
[0104] To this end, the first asymmetric balloon (210), i.e. the
longer balloon which facilitates expansion of the main structure
(110) of the endoprosthesis and of section 120, aligned with it, is
preferably inflated first. Typically balloon 210 thus increases
proximal portion 10 of the endoprosthesis to 3.5 mm and distal
portion 120 to 3 mm.
[0105] This is followed by inflation of the shorter balloon (230),
whose proximal end 236 fills recess 218 in balloon 210. Inflating
balloon 230 thus dilates section 140 of the endoprosthesis. The
proximal tapered shape of section 140 fits into the truncated form
or form with its corner missing (115) of the main or proximal
structure (110) of the endoprosthesis opposite and thus completely
covers the ostial portion or bifurcation area of the coronary
branching artery dilated and stented in the course of this
procedure.
[0106] Once the bifurcated endoprosthesis has been deployed and
installed, as shown in FIG. 7, balloons 210 and 230 can be deflated
and withdrawn.
[0107] Balloons 210 and 230 can be deflated and withdrawn
simultaneously or separately, as appropriate, after being detached
from the unit.
[0108] It is advantageous for balloons 210 and 230 to be made from
an elastic material manufactured from a plastic polymer.
[0109] This invention is not, of course, restricted to the
particular embodiment described above but stems to any and all
variants consistent with the idea embodied.
[0110] In particular, the invention is no, limited to dilation of a
bifurcation area in a coronary artery showing a lesion at the
bifurcation using endoprosthesis 100 and enmploying dilation of
balloons 210 and 230. The invention may also apply to other
blood-vessel bifurcations, arteries or veins, such as, for example
and non-limitatively, renal arteries, supra-aortic trunci, arteries
leading from the aorta to the abdomen or to the low limbs, etc.
[0111] A particular variant of the invention is one in which
balloon 210 may incorporate two portions (217 and 219), distal and
proximal respectively, located on either side of recess 218 and
having the same diameter.
[0112] During deployment, balloon 230 may be inflated before
balloon 210.
[0113] Furthermore, installation and dilation of bifurcated
endoprosthesis 100 may be envisaged using systems other than the
double balloon structure illustrated in FIGS. 8 et seqq., and, in a
corollary manner, the double-balloon system (200) may be used as a
double balloon for coronary bifurcation lesion angioplasty not
involving use of an endoprosthesis.
[0114] According to a variant of the invention, the first balloon
210 is symetric about its longitudinal axis 212. In other words the
recess 218 is annular and symetric of revolution about this axis
212.
* * * * *