Note: Descriptions are shown in the official language in which they were submitted.
2169~5~
~MPLANTABLE HEART ~ALVE
The presen~ inv~ntion relate~ to an i~plantable
heart valve o~ the mitral type.
WO Yl/19465 ~FRATER) discloses mitral he~rt val~es
co~prising, in particul~r, an ~trioventricular junction
element dafining an opening ~or blood flow, whlch opening
c~n be closed by ~t least one, and preferably four moving
m~m~anes attached ta an array of ret~;nin~ threads.
The junction element therein is ~nnular and sti~
while the retaining th~e~ds are sutured to the wall of
the myo~ar~ium.
That stru~ture rai~s nume~ous technical problem6
as~aciated with ~djustin~ the len~th of the retaining
thr~ads and the ~tif~ne~s of the junotion ele~ent.
While the operation is t~4~ng plA~e, the myocardi~w
remains fl~ccid, ~n~ ~s a result ~t is not possible to
determ$ne accur~tely the lenyth of thread requlred ~or
obtaining proper o~eration of the valve.
Under su~h con~ition~, it is difficult to ~r~ng
~0 together in repr~uc~hle m~nner the optimu~ ~onditions
for instAlling s~ch a valve.
In addition, when ~ully open, the four membrane~
define a tapering QhAnnel that oppo~e~ the flow of blood
fro~ the ~trium towards the left ven~ricle, there~y
giving rlse to func~ional pro~
A1~o, ln some cases,,the ar~y of retain;~D threads
~onstitutes the seat of calcificatlon ph~mena maklng
sRid threads brittle, there~y ~ c j.~i~g the
rsl1Ah111ty of the valve~
An obie~t of th~ prosent invention i~ to solve these
teohni c~ 1 problems in satis~acto~y ~nner.
This ob~ect is achieve~ by me~n~ of a ~itral type
implantable heart valve comprising an ~t~ioventricular
Junction element ~efining a passage for blood flow that
is suit~ble for being clo~sd by at least one ~ovin~
mem~rane, the valve ~eing chara~terized in tha~ said
junc~ion ele~ent comprises a loop Rgai~st which the
- 216945-~
periphe~al ed~e of said membrhne comes into beariny
oontac~ durin~ closure, ~nd aR ~n~horing bow ~onnected to
said membrane and disposed on the ~nterio~ slde of the
loop re.lative to th~ anat~~ T~ poBitiOn of the heart
A~ording to un advantageous charaoteristic, said
loop in~lude~ later~l cheeks de3igned to hold apart the
surroundillg ~ar~$ao w~115 to le~ve the membr~ne free to
move, ~aid ~heeks ~einy optionally provid~.d wlth
abutments limiting ~h~ an~ular displ~c~ --L of the
membrane.
In a flrst erbo~l~~nt, ~aid bow is a mo~ng - ber
and include~ means enab,l~ng it ~0 b~ fixed directly to
~he free per~pheral e~ge of s~id ~vin~ membrane and,
whe~ the v~lve is qlos~d~ pro~ide~ sealed contact with
~ai~ loop. Said me~ns for fixin~ the moving ~ow to the
periphoral ed~e o~ the membrane ~e constituted by a
lon~i~ud~nal ~lot formed in SRi~ bow, in which the
p~ripheral edge of the membrane i~ enga~ed, and having
faci~g internal later~l edges, respe~tively provided one
with a rib ~nd the other wit~ a yL~ designed to lock
together by one snap-fas~ening in the oth~r with said
mem~rane ~eing clamped ~etw~en the~.
In mo~ c~ses, ~he~ is no need to retain t~e moving
membrane s~nce its int~ventr$cul~r displace-- t away
from th~ loop is natur~lly limited by the ~u~i~ulo-
~en~ricula~ flow and by t~e intr~ventric~ar convection
flows. Op~;o~ally, addit~onal ~ut~ent~ positione~ in
appropriate ~nn~r c:an be used to guarantee th~t the
displacement i~ of de~er~n~n~ amplitude.
The bow also &erves to stiffen the frae peripheral
edge of the movin~ membrane ~nd to t~nsion it, preventiny
the pos~ibility of i~ rolling ~r ~olding up~
a~dit~ on, the n~embrane ma~r be cut out direc~tly around the
bow wh~ch then ~erves.~s a guide and provides prote~tion
a~ainst ~utting al~ng the ~ron~ lin~.
In a S~COI~h ~ IbO;3; ment, said bow is stationary ~ndis situ~ted in a pl~ne that is angularly offset ~y an
3 21 6g9 5~
angle from the plane cont~i~ing said loop, whil~ said
~oving membrane is connected to said bow by an array of
retaining th~eads. Th~ len~th of the rete~ng threads
is such that at the end o~ its ~Lcl~e, the membrane bears
ag~inst th~ anterio~ fa~e of the loop during closure. In
which case, the ~atlonary bow in~ludes through ori~ s
thxough whi~h the ret~;n~ threads pass and notches a~
the openings of the orifichs.
The incli~ation and the len~th of the ~etaining
threads a~e prefer~bly determlned so that whe~ fully op~n
the me~bra~e 3 makes an angle lyin~ in the ran~e 40 D to
90 with the pos~erior ,face or the post~rio~ edge of the
loop. In addition, the ends o~ the bow are seoured to
the outer ed~es of the loop~
According ~o ~ epe~ifio charaeteristic, the bow
posseæ~es dete 1ned anterior-po~ter~or flexibillt~. In
the embodiment with the station~ry bow and the ~rray o~
threa~s, this fl~ihi7Lty provides ~he ~et~1n~ng threads
with re$ilience when the me~brane comes lnto cont~ct with
the loop du~ing closure. Th~ resilient tencion thus
esta~lished on the retaining wires in phasa ~ith
~en~icula~ systole fa~ors opsni~g of the me~rane durin~
diastole with anticipated diastolic opening, thu~
correspondingly favorin~ tran~mitral prot~ia~toli~ flow.
~5 The valve o~ the invention oan thu~ be independent
of the ~orphology of the patien~ ' s heart b~c~ the
retaining threads ~re no longer anchored to the
~entricular wall, ~ut ~o the bow whlch i5 itself ~ecured
to the loo~ constltutin~ the atriov~-t~i~ula~ Junction
element.
Aeco~dinq to ano~her advantag~ous charae~e~i~tic,
the posterio~ face of t~ lo~p iæ of ~ width that i~
small~r than or equal to the width of the anterior f~oe.
Accordlng to yet another charaete~istic, the radius
3~ of curvature o the loop is less than or ~qual to the
radius of cur~tu~e of the stationary bow, and
substantially equal to that of the moving bow.
4 2169~51
Accordin~ to o~her ~h~racter~ stics, the wid~h of the
anterior face of the looE varies contlnuously around its
perip~er~, with A m~X; rl in its middle portion.
Similarly, the thi~kness of th~ loop varies
continuou~ly around its periphery with a x~ , ~n its
middle portion, thereby de~ining an angle between its
posterior face and its ~nterior faco lying in the range
5' to 20'.
In a first vari~nt embo~lm~nt, ~ald loo~ is closed
10 and follows the contours of the na~ural mitral ring.
~n anothex variant em~o~ nt, said loop is open.
In yet unothe~ v~rizmt, the lc)op is prov i ded, at
l~ast in part, with a sheath of birs- ,~ti~le materi~l
that provides ~aled closur- o~ sa$d passage on making
lS cont~ot with the membranç~
Provision is also made for said loop to be
elastically deformable in twi~tin~.
Prefe~bly, the section o~ the st~tionary bow is
subs~ontially circular having an ins~de ~iameter smaller
~0 than the width of the anterior ~ace of the loop.
Wi~h a moving bow, it* ~e~t1on is fitted to the
anterior fa~e of the loop so as to opt~ sealin~ o~
the cont~t.
In a ~ariant e ho~i ~nt, the croææ-6ection of s~i~
2S loop i~ polygonal or triangular.
In other em~odiments, the ~nterior fcce of the loop
possesses curv~ture tha~ is convek ~nd/or conca~e.
Prefer~bly, said mQmbran~ is o~t~i n~ by an
autograft from a ~ortion of the per$Gardium, but it coul~
~l~o be made of an~ other ~lexible or rlgi~ ~io~ ~,atible
material.
~ he looped junction element is sutu~ed to ~he
n~tur31 ring and may be made as an open loop.
Sim~larly, the pericardi~m may ~e u~e~ for ~ki ng at
3~ le~st a par~ of the sheath of the loope~ ~un~tion el ~ ent
by being sutured elsewhe~e to the n~tural ring of the
~atient.
2169~5~
-
Under su~h ~onditions, the valve has only one movin~
membrane, thereby avoidin~ any di~turbance to th~ flow of
~lood.
The invention will be better under~tood on r~dj~g
the following desqription together with the a~ompanying
drawings, in whi~h:
Figure 1 is a per~pective view of a fir~t embodiment
o~ the mitral valve o~ the invention;
Fîgure 2 ls a perspectlve vlew of a ~econ~
em~odiment of the mitral valve of t~e invention;
Figure ~ perspective view of a third ~ho~i ent
o~ the-inventio~r
Fi~ure 4 i~ a section view on a mid~l~ne of the
Figure 2 valve:
Figure Sa is ~ section vie~ through a firs~
em~odiment of thç junction el~nt ~f the valve;
Figure 5b is a ~eotion view thro~gh a ~e~ond
embodiment of the junction element o~ the valve; and
Figure 6 is a diagram showin~ how ~he valve of the
invention is implanted.
The v~ lve shown in perspective in Figures 1, 2, ~nd
3 i~ d~signed to ~e plaeed in th~ mit~ l po~ition at th~
auri~ulo-ventri~ular junction between the atrium 0 and
the ventricle V of a patient, thereby defining one~
disectionsl blood flow F fro~ ~pstream to downstream
respectively between a posterio~ or atriu~ sid~ P and an
anterior or ventricle side A, "posterior" and "anterior"
being relative to the anat~ 1 position o~ the heart.
The mitral v~lve of the i~vention in~ludes ~n
atrioventr~.~ul~r jun~ion element in the form of an open
l~op 1 ~Fi~ e~ 1 and 2~ or of a clo~ed loop ~Fi~ure 3)
~onetituting the seat ~f the valve ~nd defining ~ p~ss~e
2 for ~ommunicating blood flow F from the po~te~i~r faoe
P towards the ~nter~or ~ace A.
3S ThOE closed-loop atriov~ntricular ~ction elem~nt
fits ~he substan~ially D-sha~ed outllne of the natural
mitral ring.
2169454
The passage 2 through the middle of the open or
closed loop 1 is suitable for being close~ by at least
one mov~ng membrane 3 forming a val~e ~h~r having a
curvilinear fre~ edge.
T~e ~oviny membran~ 3 is shown in its open position
in solid l$nes an~ in its closod position in
line~.
The membrane 3 is preferably constitute~ as an
autogr~ft from ~he po~tion ~f the pQricarflium, or else it
i~ mad~ p~n~entl~ using a ~le~ible ~io~ompatible
m~terial su~h as PTFE or a rigid biD~ompatible material
such a~ tit~nium, et~. ~
When the ~trioventri~u~ar ~unctian element i~ an
open loop, the membr2ne 3 is ~ ed either to the free
15 end~ of ~he loop 1 and to the adjacent p~rtion of the
natural ring of the patient, o~ else to a ~trip for
fixi~g sAid loop ~o the natural riny of the patient.
When the loop is ~ çlosed loop, the moving membrane 3 is
~o~ns~ed vi~ its insertion ed~e 3a to the natural ring
of the pa~ient and to ~he ~dj aaent p~tion la of the
~losed loop (Fi~ure 3~.
The natural ~ing is fonmed in pArt by the ~orto-
mitral web, and ~he membrane inserted ~hereon is situated
; ~iAtely ~enç~th ~he aortio valve K~
The me~b~ne 3 move~ under drive from the blood flow
F bet~een ~ Pn positi~n where it is in contact vi~
it~ pe~iphery with the anterior f~ce 12 of the loop 1 and
an open posi~ion where it releases the pass~ge 2 (Figures
1, 2, and 3~. ~onver~ely, the membrane 3 closes unde~
dri~e from left or conve~ion inLLa~cntricular flows F'
directed from the ~entricle V (side A) tow~rd~ the at~ium
0 (side P), during diastolic 4illing of the ~entriele V
wi~h f~equency and intensity that na~rally li~it the
opening of the membrane (see Figure 6).
~S The membrane 3 is connected to an anchor bo~ S which
is dispos~d on th~ ant~rior -~ide A of the loop 1 rel~ti~e
to ~he anat~m;e~l position of the heart.
_ 7 2 1 ~ 9
In the em~o~ t s~own.in ~igure 1, the loop 1 is
open and has lateral ~he~s 13 deæigne~ to hold apdrt the
surrounding he~rt wall~ so as to lea~e the m~m~r~ne 3
free to move. ~he cheeks 13 thus ~L~vant the myo~ardiac
5 muscle protruding sinc~ that ~ould impede movement o~ the
~embrane 3. The G~eP-k~ 13 Are optionally prov~ded on
their insi~e faces w~th ~butments 14 designed to
gu~rantee a determined ~ngul~r amplit~de ~or th~
displAoQ ~nt of the me~brane 3 relative to the containin~
~he anterior face 12 of the loop 1. The positions of the
~but en~s 1~ se~ve to determine the amplitude of the
displ3~ement o~ the membr~ne 3 together with ~he bow 5
and thus to ~etenmine tne optimum opening angle o~ tne
~alve in~ependent~y of the ~ction o the irLLa~Ontricular
flowe F' Wh~rQ approp~i~te, the ving ~embrane 3 may
b~ connected to the loop 1, e.g. by suture, through
o~ifioe~ 15 formed at the end~ o said loop. The
~n~ho~ing ~ow 5 is fixed directly to all or a portion o~
the free peripheral ~dg~ of the moving b ~ne 3. The
bow 5 is m~de of a r$g~d material (met~l, etc.) or a
semi-ri~id matertal ~Delrin, pol~e~hylene, et~. ) that
i5 ~ioco~atible and ~t serves to stiffen the periphery
of the membrane 3.
When the valve close~, the bow 5 come~ in~o con~act
with the an~erior ~ace 1~ of the loop 1. The sect~ on o~
the moving bow 5 i~s the profile of the an~erior f~ce 12
of the loop 1 so ~s to opti i Y-e sealing of the contact.
The ~dius of curvat~re an~ the width of ~he loop 1 are
dete~mined as ~ funçtio~ o~ the ~adlus of cur~ature of
the moving bow.5 so as to ob~aln a ~ontaet ~urf~e th~t
is s~fficiently se~led.
T~ radius of ~urv~ur~ of th~ loop 1 is prefe~ably
substantiall~ equ~l to ~hat of the moving b~w 5~
Th~ bow 5 oan be fix~d to the mem~rane 3 ~y ~utu~e,
cli~ping, etc. One embo~ L ~n~t shown~, oonsi~t~ in
~-~i n~ sald bow ~it~ a longitud~n~l slot i~ which the
p~ripheral edge of the me~brane is re~eived; the internal
8 21 69~ ~
l~ter~l edg~s facing ~aid slot are then provided
respeotively with ~ rib and with a y~ that are
designed ~o lock together by one snap-fast~ning in the
other, thereby pinching the said ~ ne in place.
A ~riant embQ~i -. t consists ln making the bow as
two portions havin~ respective comple~entary snap-
fastenin~ means. In whi~h ca~e, the p~ripheral edge of
the membrane is ~ndwiched be~ween the two portion~ of
~he two-p~rt bow. Naturally, it i~ also po~sible to
stif$en the pe~iphery o~ the ~oving me~brane in the
vicinity to a greater or lesse~ extent by making it GUt
of a material who6e stiffne~s is loc~lly v~riable o~er
its surfaoe, either becau~e of ~hanging densi~y or else
because of changing thickness.
Provision is m~de for th~ th;r.-k~e~ o~ the ~oop 1 to
v~ry continu~usly around its periphery so as to have
~Yi -~ thickness in its m$dd}e portion ~-~ee Flgure 4, ~n
particular~ thus defining an angle ~ be~ween the
posterior and ~nterior faces 11 and 12 th~t lies in the
range ~ minutes of ~ngl~ ~ ' ) to 20' .
The loop i~ mode to have a polygon~l section and the
width af the anterior face 12 varie~ continuo~ly around
it~ periphery w~th ~Yi ~m width being in its middle
portion while the width of the pos~erior ia~e ll of the
loop 1 is less th~n or equal to the width o~ the anterior
face 12 an~ is reduced to its 1 nt llm in its midAle
portion. In a parti~ular em~odiment, pro~ision is even
made for the loop 1 ~o be t~i~ngular in section so th~t
the anterior fa~e 11 is pointed ~see Fi~u~e Sb).
N~rally the~e char~ct~ristics of the loop 1 can be
applied equal7y well to the other e~bodiments as shown in
Figure~ 2 and 3 and a~ described below.
This con$igu~tion makes it possible to obtain a
wider ~e~ring surface for ~he ~oster~or peripheral zone
of tho m~mbr~ne 3 ln its clo~ed po~$tlo~, thereby
improvln~ the sealSng of the valve.
2169~
In the eM~odiment show~ in FiSIre 2, the ~lane 3
is at~a~hed by ~n array o~ retai n j ~ threads 4 to the
stat~onary dnchor bow 5 which is disposed on the anterior
side A of the ~oop 1, In a stationary plane ~hat i$
angularly offset by an angle a from the plan~ containin~
the anterior fa~e 12 o~ the loop l. The bow 5 ;s rigid
and its fre~ ~nds a~e ~ec~red to the open loop 1,
pre~erably a~ the outside ed~es of the free ends 10.
The angular sec~or over which the moving membr~ne 3
move~ i3 deined ~y the length of the ret~ining thr~ads
4. The bow 5 li~ in ~ pl~ne that includes the free ends
lO of the l~op t and that cont~in~ th~ bisector of the
an~ular sector throug~ wh1ch the membrane 3 moves.
The bow 5 is flç~bl~ in the ante~ior-posterior
plane.
The ~n~le ~ an~ tha len~th of th~ thr~Ads 4 a~
deter~ined SO that wh~n fully open the ~e~bra~e 3 i~ at
an angle y that lies in the range 40 ~o 90 relative to
the plane posterior fa~e ll or the po~terio~ ~dge of the
loop l.
In the closed po~it~on, the membrane 3 iS at the end
of its s~ro~e and is in bearing contact against ~he
ante~ior face 12 of the loop 1.
Under such conditions, ~he angle a is equal to
~y~ be~se the bow is n~ce~rily h~lfway b~ n
the open position and the cl 0~6~ po~ition.
I~ orde~ to enable the membrane 3 to pass inside the
~tationary bow, ~he ~adius of cu~vature of the loop 1 is
less than or equal to that of the bow 5.
The bow 5 is circular in ~eotion h~vin~ an insl~e
diameter that is considerably sm~ller than the width of
the anterior face l~ of .the loop 1, and th~t is
preferably about one milli~eter.
~he re~eining threa~s 4 are ~ixed to th~ bow 5
35 either by pa~sing thro~gh orifice~ 50 that open out into
ret~ining notches ~Oa, or else ~er~ly by ~eing ret~in~
in aid notc~es.
' 10 21694~
In the ~.bo~ t o~ ~q~r~ ~, the loop 1 has ~n
ant~rio~ ~ace 12 with convex curvature, but e~bodi~ents
~ay also be designed in whi~h said curvature is ~otally
or p~rtially concave.
In the ~ ~dime~t of Fi~ure 5b, the section of the
loop 1 is triangul~r, par~icularly in its middle portion,
however it would also be possi~le to desiyn a slopin~
anterior face .in th~ mid~le portion (~ee ~igure 4).
The lo~p l iæ provided ~t least in pa~t with a
shedth 6 o~ bloco~ibl~ ~ e.i~l whieh ensure~ ~ealed
~'osure of the p~ss~e 2 when in be~ing conta~t with ~he
membrane 3.
The ~he~th 6 ~ay be made by uS ing a portion of the
perio~rdi~m or any other flexible hiocompati~le material.
~der such eonditions, the sheath 6 i~ sutured ~o the
natural ring of the pati~nt whilc~ leaving a nArrow fixiny
strip 7 of the pericardium or of the h~CC~. ~a~i~le
material between the sheathe~ loop and the suturing to
~he ring. ~his increases thc freedom of the fixing
be~w~en the loop l and the natural mitral ring of ~he
patient to defo~m elastically in to~Sion, in elon~ation,
and/or in compression during the cardiac oy~le.
