U.S. patent application number 11/934095 was filed with the patent office on 2008-11-20 for device for shrinking or reinforcing the valvular orifices of the heart.
This patent application is currently assigned to BIORING SA. Invention is credited to Raymond Andrieu, Afksendiyos Kalangos, Philippe Le Goff.
Application Number | 20080288062 11/934095 |
Document ID | / |
Family ID | 11003923 |
Filed Date | 2008-11-20 |
United States Patent
Application |
20080288062 |
Kind Code |
A1 |
Andrieu; Raymond ; et
al. |
November 20, 2008 |
DEVICE FOR SHRINKING OR REINFORCING THE VALVULAR ORIFICES OF THE
HEART
Abstract
A device for shrinking and/or reinforcing the heart valve
orifices includes a thick link (1) made of a bioresorbable, soft
and curved material. It is secured at one of its ends to at least a
thin yarn (3) whereof the end is fixed to a curved needle.
Inventors: |
Andrieu; Raymond; (Yens,
CH) ; Le Goff; Philippe; (Le Mont Sur Lausanne,
CH) ; Kalangos; Afksendiyos; (Geneva, CH) |
Correspondence
Address: |
YOUNG & THOMPSON
209 Madison Street, Suite 500
ALEXANDRIA
VA
22314
US
|
Assignee: |
BIORING SA
LONAY
CH
AFKSENDIYOS KALANGOS
GENEVA
CH
|
Family ID: |
11003923 |
Appl. No.: |
11/934095 |
Filed: |
November 2, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10296449 |
Jul 11, 2003 |
7347870 |
|
|
PCT/IB00/01605 |
Nov 7, 2000 |
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11934095 |
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Current U.S.
Class: |
623/2.36 |
Current CPC
Class: |
A61F 2210/0004 20130101;
A61B 2017/00004 20130101; A61L 31/148 20130101; A61B 2017/00783
20130101; A61F 2002/30062 20130101; A61F 2/2445 20130101; A61B
2017/06057 20130101; A61B 17/06166 20130101 |
Class at
Publication: |
623/2.36 |
International
Class: |
A61F 2/24 20060101
A61F002/24 |
Foreign Application Data
Date |
Code |
Application Number |
May 25, 2000 |
IB |
PCT/IB00/00707 |
Claims
1. Device for contracting and/or reinforcing valvular orifices of a
heart, comprising: a thick connection (1) having two distal ends
separated from each other, the thick connection being flexible and
curved between the two distal ends, the thick connection have a
longitudinal axis, a thick connection (1) being of a first
resorbable material; a thin filament (3) having a first end
extending from a first of said two distal ends, the thin filament
extending out of the first distal end along a direction coaxial
with the thick connection, the thin filament being of the first
resorbable material, the thin filament and the thick connection
being realized in one piece of fabrication; and a curved needle (4)
fixed to a second end of the thin filament, wherein, the filament
(3) permits exerting a longitudinal traction on the thick
connection (1) in the direction of the longitudinal axis of the
thick connection, the longitudinal traction is adapted to allow the
thick connection to be introduced inside the tissue of a valvular
orifice to be treated.
2. Device according to claim 1, wherein, the curvature of the
needle (4) is substantially equal to the curvature of the
connection (1), and the curvature of the needle and the curvature
of the connection is substantially equal to a curvature that the
valvular orifice to be treated to allow the thick connection (1) to
be introduced inside the tissue of the valvular orifice to be
treated.
3. Device according to claim 1, further comprising: another thin
filament (3) having a first end extending from a second of said two
distal ends, the another thin filament extending out of the first
distal end along a direction coaxial with the thick connection, the
another thin filament being of the first resorbable material, and
the another thin filament and the thick connection being realized
in one piece of fabrication; and another curved needle (4) fixed to
a second end of the another thin filament.
4. Device according to claim 2, further comprising: another thin
filament (3) having a first end extending from a second of said two
distal ends, the another thin filament extending out of the first
distal end along a direction coaxial with the thick connection, the
another thin filament being of the first resorbable material, and
the another thin filament and the thick connection being realized
in one piece of fabrication; and another curved needle (4) fixed to
a second end of the another thin filament.
5. Device according to claim 1, wherein the length of the needle
(4) is substantially equal to the length of the connection (1),
corresponding substantially to the portion of the periphery of the
valvular orifice into which it is to be implanted.
6. Device according to claim 1, further comprising: a securement
member (2) located at a second of the two distal ends.
7. Device according to claim 1, wherein a cross-section of the
connection (1) is circular or polygonal.
8. Device according to claim 1, wherein the connection (1)
comprises a core made of a polymer that can be described by the
general formula -[--X--C(O)--R1-Y--R2-]--in which C(O) designates a
>C.dbd.O group; X designates an oxygen atom, Y designates an
oxygen atom or a chemical bond connecting R1 to R2; R1 and R2
designating linear or branched carbon chains and containing 0 to 5
carbon atoms and preferably 0 to 3 carbon atoms.
9. Device according to claim 8, wherein the polymer used is of the
polylactide or polyglycolide or polylactone or
polyalkylenecarbonate type or else preferably of the polydioxanone
type or any other type of polymer, provided that this latter is
obtained from a cyclic compound having the general formula
C.sub.4H.sub.6O.sub.3 and having a >C.dbd.O group.
10. Device according to claim 1 wherein the connection (1)
comprises a core of a slowly resorbable material and a layer of a
more rapidly resorbable material.
11. Device according to claim 10, wherein the polymer used to
constitute the core of the connection (1) is a copolymer obtained
by combination of different monomers leading to a polymer that can
be described by the general formula -[--X--C(O)--R1-Y--R2-]- in
which C(O) designates a >C.dbd.O group; X designates an oxygen
atom, Y designates an oxygen atom or a chemical bond connecting R1
to R2; R1 and R2 designating linear or branched carbon chains and
containing 0 to 5 carbon atoms and preferably 0 to 3 carbon
atoms.
12. Device according to claim 10, wherein the slowly resorbable
material is a polymer that can be described by the general formula
-[--X--C(O)--R1-Y--R2-]- in which C(O) designates a >C.dbd.O
group; X designates an oxygen atom, Y designates an oxygen atom or
a chemical bond connecting R1 to R2; R1 and R2 designating linear
or branched carbon chains and containing 0 to 5 carbon atoms and
preferably 0 to 3 carbon atoms, and that the more rapidly
reabsorbable material is a polymer that can be described by the
general formula -[X--C(O)--R1-Y--R2-]- in which C(O) designates a
>C.dbd.O group; X designates an oxygen atom, Y designates an
oxygen atom or a chemical bond connecting R1 to R2; and R1 and R2
designates linear or branched carbon chains containing 0 to 5
carbon atoms and preferably 0 to 3 carbon atoms, to which are added
collagen and catgut.
13. Device according to claim 12, wherein the slowly resorbable
material is a polymer of the polydioxanone type or of any other
type provided that the polymer is obtained from a cyclic compound
responding to the general formula C.sub.4H.sub.6O.sub.3 and having
a >C=o group and that the more rapidly resorbable material is a
polymer that can be described by the general formula
-[--X--C(O)--R1-Y--R2-]-in which C(O) designates a >C.dbd.O
group; X designates an oxygen atom, Y designates an oxygen atom or
a chemical bond connecting R1 to R2; R1 and R2 designating linear
or branched carbon chains and containing 0 to 5 carbon atoms and
preferably 0 to 3 carbon atoms, to which are added collagen and
catgut.
14. Device according to claim 1, wherein the connection comprises a
series of enlargements (5) and thinned portions (6).
15. Device according to claim 14, wherein the enlargements (5) of
the connection comprise the first resorbable material covered with
a second resorbable material whilst the thinned regions (6) of the
connection are constituted by the first resorbable material.
16. Device for contracting and/or reinforcing valvular orifices of
a heart, comprising: a thick connection (1) made of a first
resorbable material; a thin filament (3) extending from a first end
of the connection along a direction coaxial with the connection,
the thin filament being of the first resorbable material, the thin
filament and the connection being made of one piece during
manufacture; and a needle (4) fixed to an end of the thin filament,
the needle permitting emplanting the connection, a curve and a
length of the needle respectively corresponding to the curve of the
ring of a valvular orifice to be treated and to the length of a
portion of a perimeter of the valvular orifice, the connection
having a length and a curve corresponding to the length and the
curve of the needle, wherein, the filament permits exerting a
longitudinal traction on the connection in the direction of the
longitudinal axis of the thick connection, the longitudinal
traction is adapted to allow the thick connection to be introduced
inside the tissue of the valvular orifice to be treated.
17. The device of claim 16, wherein, the connection comprises a
series of enlargements (5) and thinned portions (6), the
enlargements are covered with a second resorbable material, the
second resorbable material being more rapidly resorbable than the
first resorbable material.
18. The device of claim 16, further comprising: another thick
connection (1) made of the first resorbable material and connected
to a second end of the thick connection; another thin filament (3)
having a first end extending from an end of the another thick
connection, the another thin filament extending out of the end
along a direction coaxial with the another thick connection, the
another thin filament being of the first resorbable material, and
the another thin filament and the another thick connection being
realized in one piece of fabrication; and another curved needle (4)
fixed to a second end of the another thin filament.
19. The device of claim 16, further comprising: another thin
filament (3) having a first end extending from a second end of the
thick connection, the another thin filament extending out of the
first end along a direction coaxial with the thick connection, the
another thin filament being of the first resorbable material, and
the another thin filament and the thick connection being realized
in one piece of fabrication; and another curved needle (4) fixed to
a second end of the another thin filament.
Description
[0001] Lesions of the valvular orifices of the heart, whether of
the sigmoidal valvules of the aorta or of the pulmonary artery or
mitral or tricuspidal valves, occur in 80 to 90% of the cases of a
prolapsis or restriction which lead to dilation of the ring by
enlarging the cardiac cavities in question and in practically all
the rest of the cases a dilation of the ring without associated
valvular lesions.
[0002] After correction of the associated valvular lesions, it is
necessary to correct at the same time the dilation of the valvular
ring and to hold it in its normal dimension. To prevent recurrence
of such lesions, it is necessary to reinforce the ring surrounding
the valvular orifices.
[0003] To carry out such repairs of the valvular orifices, there
have been proposed several types of rigid or flexible implants
having the general shape of rings, such as the DURAN, CARPENTIER or
PUIG-MASSANA rings, or segments such as that of COSGROVE. These
rigid or flexible rings or segments or disposed and stitched along
the periphery of the ring of the valvular orifice to be repaired.
The opening of the valvular orifice is thus brought to the desired
dimension, generally calculated in proportion to the surface of the
body of the patient, and maintained in this normal dimension.
[0004] The document EP 0 338 994 discloses such a device for the
surgical correction of tricuspidal insufficiency, adapted to be
fixed, specifically stitched, along the periphery of the ring of
the valvular orifice to be repaired, this usually on the internal
surface of this valvular orifice. So as to accelerate the process
of securement by suturing, this device can be provided at its ends
with a filament and a needle. This filament and corresponding
needle however serve no other purpose than more rapid suturing,
once the insertion of the device in the heart has been completed,
and the device thus remains in the context of known implants and
implantation techniques by improving only the speed of a
conventional surgical procedure.
[0005] These implanted rings are generally of synthetic material or
metal and can predispose certain patients to valvular infections in
the case of bacteria, requiring therapeutical, curative and
preventive treatments and, as the case may be, a new
intervention.
[0006] Moreover, when these rigid or flexible rings are used in
babies, they prevent normal growth of the ring of the valvular
orifice in question, which leads to stenoses and also to one or
several new interventions to enlarge the ring and replace the
stenoses and also to one or several new successive interventions to
enlarge the ring and to replace the stenotic valve.
[0007] The document WO 97/16135 discloses a resorbable annular
cardiac prosthesis. The ring disclosed in this document is formed
of a biodegradable material so as to permit the replacement of this
material by biological material belonging to the patient during the
resorption period. However, this ring is also adapted to be
disposed in a conventional manner on the internal surface of the
valvular orifice along the periphery of the ring of this valvular
orifice to be repaired.
[0008] The present invention has for its object a device to
contract and/or to reinforce the valvular orifices of the heart
which avoids any predisposition to infection and which permits the
normal growth of the ring of the valve in infants, thereby avoiding
stenoses or successive interventions; moreover, the device is
arranged so as to permit a surgical procedure altogether new and
innovative and thus improves greatly the speed, the facility and
the applicability of the surgical procedure.
[0009] The device to contract and/or reinforce the valvular
orifices of the heart is distinguished by the characteristics set
forth in claim 1 and/or claim 2.
[0010] The accompanying drawings show schematically and by way of
example several embodiments of the device according to the
invention.
[0011] FIG. 1 is a schematic representation of the human heart.
[0012] FIGS. 2, 3 and 4 are simplified schematics showing
respectively the mitral valve, the tricuspid valve and the
sigmoidal valves.
[0013] FIG. 5 shows in a schematic or simplified way a first
embodiment of the device according to the invention.
[0014] FIG. 6 shows in a schematic or simplified way a second
embodiment of the device according to the invention.
[0015] FIG. 7 shows in a schematic or simplified way a third
embodiment of the device according to the invention.
[0016] FIG. 8 shows in a schematic or simplified way a fourth
embodiment of the device according to the invention.
[0017] FIG. 9 shows in a schematic or simplified way a modification
of the device shown in FIG. 7.
[0018] In place of rigidly and/or definitively fixing a rigid or
flexible ring or segment along all or a part of the periphery of
the valvular orifice, as was done until now, the present technique
consists in arranging a flexible connection along all or a part of
the periphery of the valvular orifice at the interior of the
endocardium, namely the layer of tissue located on the internal
side of the myocardial muscle, to define the dimension of the
valvular opening by a length defined by the connection, to fix the
latter at one or two points of the endocardium for example by
points of suturing.
[0019] Moreover, in the present technique, there is utilized a
resorbable connection (biodegradable or bioabsorbable) which is to
say biodegradable and not giving rise to an immune response on the
part of the organism. In what follows of this paper, the term
resorbable will be used to define either bioabsorbable or
biodegradable and the suture filaments resorbable or not. In a
first instance after the operation, the connection holds the
valvular ring at its normal or desired dimension, thereby
preventing its dilation.
[0020] Then, by the action of resorption of the connection within
the endomicardial layer, the organism creates, by reaction, a scar
along the connection characterized by fibrous tissue having a
greater resistance to stretching. Thus, once the connection is
resorbed by the organism, folding the valvular orifice at the
desired dimension is effected by the rigidity of this fibrous
tissue of the scar.
[0021] Because the residual scar is constituted of biological
tissues belonging to the patient, there is no predisposition to
infection, but above all this scar can increase normally in the
course of the process of growth of the infant, which avoids
problems of late stenoses.
[0022] This new technique is rendered possible by the device for
repairing lesions, for contraction and/or reinforcement of the
valvular orifices of the heart according to the present invention.
In a first embodiment, this device comprises a connection 1, made
of a material resorbable by the organism, terminating at one of its
ends in a loop 2 or a stop member and of resorbable securement or
not, for example a hook or barb permitting the securement of this
end to the endomiocardium. The other end of the connection 1 is
secured, generally made of one piece during manufacture, to a thin
filament 3 that is very flexible, such as a suturing filament. This
thin filament 3 is preferably also resorbable and generally formed
of the same material as the connection 1.
[0023] This filament 3 is fixed at its free end to a needle 4
permitting emplanting the connection 1 of the device.
[0024] It is evident that the present device is made in several
sizes because for easy emplacement, it is preferable that the curve
and the length of the needle 4 correspond to the curve of the ring
of the valvular orifice and to the length of the portion of
perimeter of the orifice that is to be provided with the connection
1 of the device.
[0025] Similarly, it is preferable that the connection 1 have a
length and if possible a curve corresponding to the portion of the
periphery of the valvular orifice to be provided with the
connection.
[0026] Thus the surgeon can, in the case of the valves shown in
FIGS. 2 and 3, introduce the needle 4 at X into the endomiocardium
of the valvular ring A, pass the needle within this layer of tissue
to point Y of the valvular ring A, because the curve of the needle
4 and its length are adapted to the valve which is to be equipped
therewith.
[0027] The surgeon brings out the needle 4 at the point Y and draws
the filament 3 to move the connection 1 into position in which the
securement member 2 is located adjacent the point of introduction X
and the junction between the connection 1 and the thin filament 3
is itself located at the exit point Y. The surgeon fixes by taking
several suture points and by if desired using a stop, for example a
button, the connection 1 to the exit point Y with the filament 3,
then cuts this filament 3. Finally, the surgeon fixes and buries in
the endomiocardium by several suture points the loop 2 or the stop
provided at the free end of the connection 1.
[0028] It is also possible to provide all the perimeter of the
valvular ring with a connection 1. In this case, the points X and Y
are near each other or coincide and the filaments 3 at the two ends
of the connection 1 are knotted together, cut and buried in the
endomiocardium.
[0029] The connection 1 has a curvature corresponding approximately
to that of the ring of the orifice of the valve and the quantity of
resorbable material depends on the mass of fibrous tissues which it
is desired to induce by resorption to obtain the desired rigidity
of this natural scar which over the long term alone will ensure the
holding of the ring of the orifice of the valve and prevent any
dilation of the latter.
[0030] Several sizes of the device are provided as a function of
the diameter of the valvular orifice and of the body surface of the
patient, the connection 1 and the needle 4 depending on this
diameter and on the portion X-Y of the periphery of the valvular
orifice to be outfitted. Moreover, for each of the sizes, several
types are provided with different thicknesses of the connection 1.
In a modification of the described device, the connection 1 of
resorbable material is clad with a layer of a second material more
rapidly resorbable than that used to make the internal portion of
the connection. In this way, there is obtained by the resorption of
this layer or cladding, an initial rapid resorption, for example
over several days to several weeks, and hence the more rapid
formation of fibrous tissue permitting quasi-immediate
reinforcement of the valvular orifice. This initial rapid scar
formation is followed by a slow scar formation, six to twelve
months, due to the resorption of the central portion of the
connection 1.
[0031] To determine the size of the device to be used, the surgeon
has testers, templates of the shape of the valvular orifices, but
of different cross-sections. By selecting a tester corresponding to
the size of the surface of the anterior flap of the mitral or
tricuspidal valve to be repaired or to the diameter of the
sinotubular junction where the three sigmoidal valvules coapt, the
surgeon determines the size of the device to be used. The choice of
the type of device within the predetermined size is made as a
function of the age of the patient, of the body surface, and of the
condition of the lesion. The greater the quantity of resorbable
material of the connection 1, the larger will be the scar and the
stronger will be the reinforcement of the ring of the valvular
orifice.
[0032] In the second embodiment of the device shown in FIG. 6, the
connection has a series of enlargements 5 and of thinned portions
6. This type of device gives rise to light or weak scarring at the
thinned portions 6 and strong scarring at the enlargements 5. This
is particularly interesting in young infants or babies because
during growth of the weakly scarred portions, corresponding to the
thinned portions 6, these can easily stretch as a function of the
growth of the subject.
[0033] Here again, it is preferable that the curvature of the
needle 4 and that of the resorbable connection 5, 6 correspond
substantially to that of the valvular orifice to be thus
equipped.
[0034] In this embodiment also, the resorbable connection 5, 6 can
be covered with a layer of more rapidly resorbable material than
that used to make the interior of the connection, so as to create a
two-stage resorption.
[0035] The third embodiment of the device shown in FIG. 7 is more
particularly, but not exclusively, adapted for the case of repair,
contraction or reinforcement of valvular orifices in which it is
necessary to reinforce all the periphery of the valvular orifice,
for example in the case of the mitral, tricuspid and sigmoidal
valves.
[0036] This device comprises a thick and resorbable connection 1
whose ends both comprise thin filaments 3 each one provided with a
needle 4.
[0037] With the help of one or the other needle 4, the surgeon
introduces the resorbable connection 1 into the endomiocardium so
as to form a loop then he knots the two thin filaments 3, also
resorbable, of the device so as to hold the connection 1 closed on
itself. The rest of the filament is cut away (see FIG. 9).
[0038] Here again, the curvature of the needles 4 and the
connection 1 of the device correspond preferably to the nominal
curvature of the valvular orifice to be treated.
[0039] Of course, the connection 1 can comprise, as shown in FIG.
6, enlargements and thin portions. Similarly, this connection 1 can
comprise a layer or a cladding made of a more rapidly resorbable
material than that forming the interior of the connection 1 of the
device, so as to obtain two-stage resorption.
[0040] The fourth embodiment of the device according to the
invention, shown in FIG. 8, is more particularly adapted to the
repair of sigmoidal valves formed of three lobes L.
[0041] In this embodiment, the connections constituted by several,
in this case three, portions 7, 8, 9. The central portion 8 is
connected to the lateral portions 7, 9 of this central portion and
these lateral portions each comprise a filament 3 terminating in a
needle 4.
[0042] The curvature of the needles 4 and of the portions 7, 8, 9
of the connection correspond to the curvature of the free edges B
of the lobes L of the sigmoidal valve. With the help of needles 4,
there is introduced into the endomiocardium along the edges B of
the lobes L of the valvule, the portions 7, 8, 9 such that each of
them corresponds to a lobe L.
[0043] The filaments 3 are then knotted together and cut.
[0044] Here again, the connection and possibly the filaments 3 are
of a resorbable material, if desired two-stage as described
above.
[0045] The principal advantages of the device described are as
follows:
[0046] absence of predisposition to infection because the implanted
connection is biologically resorbable.
[0047] facility of emplacement of the connection because its shape
and the shape of the needles, is adapted to the curve of the
valvular orifice. Thus, this permits entering into the
endomiocardium at a place and leaving it at another place or at the
same place, without intermediate perforation.
[0048] the possibility of creating resorption in two stages.
[0049] the possibility of creating distributions reinforcing the
ring of the valvular orifice and avoiding dilation whilst
permitting this valvular ring to grow as a function of the growth
of the subject, which avoids late stenoses.
[0050] Numerous variations can be envisaged, particularly as to the
shape and composition of the device and more particularly to its
thick portion of the connection.
[0051] This connection can have a diameter of the order of 0.2 mm
to several millimeters, according to the conditions of use. Its
cross-section may be circular, oval, polygonal and particularly
rectangular to give it a greater resistance to deformation. This
connection is generally flexible, but returns by its natural
elasticity to its curved shape corresponding approximately to that
of the valvular orifice.
[0052] One of the novel characteristics of the invention consists
in using one or several resorbable materials for the production of
the connection 1 and its filaments 3. Thus, if the resorbable
materials are known for various applications in the field of
medical devices, for example as suture filaments, or as prostheses,
or else as devices for the controlled release of medicinal
substances into the organism, there exists no application in which
the material has to ensure, in addition to its primary function of
a repair element, a function of inducing a curative and evolutive
action from the organism itself.
[0053] The resorbable materials finding application in the fields
of health are obtained from tissues or proteins from the animal
kingdom, such as collagen or catgut, or from polymers produced
synthetically.
[0054] The chemical nature of the principal polymers known to be
resorbable, include polyesters, polyorthoesters, polyanhydrides,
poly(ether)esters, polyaminoacids and polydepsipeptides (see for
example: B. Buchholz; J. Mater. Sci. Mater: Med. 4 (1993)
381-388).
[0055] More schematically, but not exclusively, the resorbable
polymers can be described by a structure corresponding to the
general formula:
[--X1-C(o)--R1-Y1-R2-]-[--X2-C(O)--R3-Y2-R4-]
in which: [0056] C(O) designates a >C.dbd.O group, [0057] X1; X2
designate an oxygen atom or an NH group, [0058] Y1 (respectively
Y2) designates an oxygen atom, or an NH group, or a chemical
connection directly connecting R1 to R3) respectively R2 to R4),
[0059] R1; R2; R3; R4 designate linear or branched carbon chains,
saturated or partially unsaturated, bearing or not hetero atoms and
containing 0 to 10 carbon atoms.
[0060] When in this general formula, X1 is equal to X2 and Y1 is
equal to Y2 and R1 is equal to R3 and R2 is equal to R4, the
obtained polymer is called a homopolymer. In the contrary case, the
polymer obtained is called a copolymer.
[0061] Among these polymers, the inventors have focused attention
on the polymers that can be described by a structure responding to
a general formula:
-[--X1-C(O)--R1-Y1-R2-]-[--X2-C(O)--R3-Y2-R4-]
[0062] N which: [0063] C(O) designates a >C.dbd.O group, [0064]
X1; X2 designates an oxygen atom, [0065] Y1 (respectively Y2)
designates an oxygen atom or a chemical bond directly connecting R1
to R3 (respectively R2 to R4), [0066] R1; R2; R3; R4 designate
linear or branched carbon chains and contain 0 to 5 carbon atoms
and preferably 0 to 3 atoms.
[0067] These types of polymers include for example polylactides,
polyglycolides, polydioxanones, polyalkylenecarbonates, and
polylactones. To these homopolymers must be further added the
copolymers obtained by a combination of the different monomers.
[0068] These polymers are known for their ability to be resorbed in
vivo according to known and predictable modes of resorption.
[0069] Moreover, among these polymers, certain have particularly
interesting characteristics to enter into the production of the
device as described in claim 1.
[0070] Thus, for example, the polydioxanones are known to resorb
more slowly than the polylactides, or the polyglycolides, or else
catgut or collagen.
[0071] On the other hand, the flexibility of the material obtained
also depends on the nature of the polymer used. The mechanical
characteristics of the obtained material will vary for example with
the chemical nature of the structure, the molecular weight, the
polymerization process, the technique of using the material, . . .
.
[0072] Optimization of the different parameters bearing on the
characteristics of the obtained material, has resulted in a
preference for polydioxanones to produce the connection 1. The
polydioxanones are polymers obtained from cyclic monomers having
the general formula C.sub.4H.sub.6O.sub.3 and have a >C--O
group. They offer in vivo resorption kinetics compatible with the
formation of scar mass and can be developed with the mechanical
characteristics necessary for their use.
[0073] In the case in which the connection 1 is formed by two
different materials, it can be provided that the latter comprises
an internal portion of polydioxanone and an external cladding made
of a more rapidly resorbable polymer. The external cladding gives
rise to a first fibrous reaction during its early resorption whilst
protecting the polydioxanone which will begin its slow resorption
only when the external cladding has been resorbed. There is thus
obtained a more tardy resorption which leads to more consolidated
fibrous reaction.
[0074] In the case in which the connection comprises enlargements
and thinned portions, the principal thick segments 5 will comprise
the two materials whilst the thin connection portions 6 could
comprise only one of the two mentioned materials.
[0075] Instead of using monofilament material for the connection,
there can be used woven or multi-fibrous materials.
* * * * *