(12) United States Patent
`De Paulis
`
`US006352554B2
`(10) Patent N0.2
`US 6,352,554 B2
`(45) Date of Patent:
`*Mar. 5, 2002
`
`(54) PROSTHETIC TUBULAR AORTIC CONDUIT
`AND METHOD FOR MANUFACTURING
`THE SAME
`
`EP
`GB
`
`6/1999
`0 666 066 B1
`2 312 485 A 10/1997
`
`OTHER PUBLICATIONS
`
`(75) Inventor: Ruggero De Paulis, Rome (IT)
`(73) Assigneez Sulzer Vascutek Limited, Inchinnan
`(GB)
`
`(*) Notice:
`
`This patent issued on a continued pros-
`ecunon apphpanot} ?led under 37 CFR
`1.53(d), and 1s subJect to the tWenty year
`atent term revisions of 35 U S C
`I1)54(a)(2)
`p
`'
`'
`'
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 0 days.
`
`_
`(21) Appl. NO.. 09/301,839
`(22) Filed:
`Apr. 29, 1999
`
`Related US. Application Data
`(60) Provisional application NO_ 60/084,710’ ?led on May 8’
`1998.
`
`(51) Int. Cl.7 ............................. .. A61F 2/06; A61F 2/24
`_
`_
`_
`(52) US‘ Cl‘ """"""""" " 623/1‘26’ 623/129’
`
`(58) Field Of Search ............................. .. 623/115, 1.16,
`623/1~24> 1~26> 13> 23~64> 23~68> 1~28>
`1~29> 11> 19
`
`(56)
`
`_
`References Clted
`Us PATENT DOCUMENTS
`
`2
`
`""""
`
`David et al., ‘An aort1c valve—spar’mg operation for patients
`With aort1c mcompetence .
`.
`.
`, from The Journal of
`Thoracic & Cardiovascular Surgery, vol. 103, No. 4, Apr.
`1992, PP~ 617—622~
`Thubrikar et al., “Stress Sharing BetWeen the Sinus and
`Lea?ets of Canine Aortic Valve”,, from The Annals of
`Thoracic Surgery, vol. 42, No. 4, Oct. 1986, pp. 434—440.
`
`(List Continued On neXt page.)
`
`Primary Examiner—Bruce SnoW
`Assistant Examiner—Brian E. Pelle rino
`g
`(74) Attorney, Agent, or Firm—Ratner & Prestia
`
`(57)
`
`ABSTRACT
`
`_
`_
`_
`_
`_
`Aprosthet1c aort1c conduit for replacmg a root portion of an
`aorta is provided. The conduit comprises a ?rst tubular
`portion and a second tubular portion Which are connected
`.
`.
`together along a substantially common axis. The second
`tubular portion does not substantially deform in a longitu
`dinal direction and has resilient means Which alloW said
`Second portion to be expandable in a lateral direction ThiS
`second portion is able to deform laterally to mimic the
`function of the sinuses of Valsalva. The method of manu
`facturing such a conduit comprises the steps of: a) providing
`a ?rst tubular conduit suitable for use in heart surgery and
`having a longitudinal axis and ?rst resilient means alloWing
`some expansion in the longitudinal direction only;
`b) securing to one of the ends of this ‘?rst conduit a second
`
`5:123:919 A
`5,139,515 A
`
`6/1992 Sauter et aL _ _ _ _ _
`8/1992 Robicsek ____ __
`
`_ _ _ _ __ 623/2
`623/1
`
`tubular conduit suitable for use in heart surgery, th1s
`second conduit having second resilient means Which
`
`5,476,506 A 12/1995 Lunn _ _ _ _ _ _ _ _ _ _ _ _
`_ _ _ _ _ __ 623/1
`5,788,626 A * 8/1998 Thompson ............... .. 623/115
`
`FOREIGN PATENT DOCUMENTS
`
`alloWs some expansion in the lateral direction only.
`
`EP
`
`0 666 066 A1
`
`8/1995
`
`12 Claims, 6 Drawing Sheets
`
`Edwards Lifesciences Corporation, et al. Exhibit 1121, Page 1 of 13
`
`

`

`US 6,352,554 B2
`Page 2
`
`OTHER PUBLICATIONS
`Cabrol et a1., “Complete replacement of the ascending aorta
`With reimplantation of the coronary arteries”, J. Thorac.
`Cardiovasc. Surg., vol. 81, No. 2, Feb. 1981, pp. 309—315.
`Bentall et al., “A technique for complete replacement of the
`ascending aorta”, Thorax, 23, 338, 1968, pp. 338—339.
`Kunzelman et a1., “Aortic root and valve relationships”, J.
`Thorac. Cardiovasc. Surg., vol. 107, No. 1, Jan. 1994, pp.
`162—170.
`
`Sarsam et a1., “Remodeling of the aortic valve anulus”, J.
`Thorac. Cardiovasc. Surg., vol. 105, No. 3, Mar. 1993, pp.
`435—438.
`
`Marian I. Ionescu, “Tissue Heart Valves”, Figure 9.2, Right
`Ventricular Out?ow Tract Reconstruction, The ButterWorth
`Group, 1979.
`
`* cited by examiner
`
`Edwards Lifesciences Corporation, et al. Exhibit 1121, Page 2 of 13
`
`

`

`U.S. Patent
`
`Mar. 5,2002
`
`Sheet 1 0f 6
`
`US 6,352,554 B2
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`Fig. 1 (Prior Art)
`
`Edwards Lifesciences Corporation, et al. Exhibit 1121, Page 3 of 13
`
`

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`U.S. Patent
`
`Mar. 5,2002
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`Sheet 2 0f 6
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`US 6,352,554 B2
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`2\
`QB x
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`Edwards Lifesciences Corporation, et al. Exhibit 1121, Page 4 of 13
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`

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`U.S. Patent
`
`Mar. 5,2002
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`Sheet 3 0f 6
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`US 6,352,554 B2
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`Fig. 2a
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`Edwards Lifesciences Corporation, et al. Exhibit 1121, Page 5 of 13
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`

`

`
`
`Edwards Lifesciences Corporation, et al. Exhibit 1121, Page 6 of 13
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`

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`U.S. Patent
`
`Mar. 5,2002
`
`Sheet 5 0f 6
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`US 6,352,554 B2
`
`10'
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`Edwards Lifesciences Corporation, et al. Exhibit 1121, Page 7 of 13
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`

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`U S Patent
`
`Mar. 5, 2002
`
`Sheet 6 0f 6
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`US 6,352,554 B2
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`0 R
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`1 4
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`AO RTA
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`12 48
`., / 28
`
`Fig. 6
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`Edwards Lifesciences Corporation, et al. Exhibit 1121, Page 8 of 13
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`US 6,352,554 B2
`
`1
`PROSTHETIC TUBULAR AORTIC CONDUIT
`AND METHOD FOR MANUFACTURING
`THE SAME
`
`This application claims bene?t of provisional U.S. Ser.
`No. 60/084,710 ?led May 8, 1998.
`
`FIELD OF THE INVENTION
`
`Aprosthetic aortic conduit for replacing a root portion of
`the aorta and a method for manufacturing the same.
`
`10
`
`BACKGROUND OF THE INVENTION
`
`2
`modi?cation of the standard technique Was also introduced
`by Cabrol et al (Cabrol C, Pavie A, Gandjbakhch I. et al:
`Complete replacement of the ascending aorta With reimplan
`tation of the coronary arteries. NeW Surgical approach, J
`Thorac Cardiovasc Surg 1981: 81; 309—15) for those cases
`of dif?cult presentation (loW lying coronary ostia, calci?ed
`coronary ostia, tissue ?brosis in redo cases) Where the
`coronary ostia are reattached to the aortic conduit by inter
`position of a small conduit made in DACRON. DACRON is
`the Trade Name for a material formed from straight chain
`polyester; the material may also be knoWn as TERYLENE.
`If the aortic valve lea?ets are normal, a valve-sparing
`aortic root remodelling procedure Which keeps the natural
`patient valve on site is a reasonable alternative in certain
`individuals. David and Feindel (David T. E., Feindel C. M.:
`An aortic valve-sparing operation for patients With aortic
`incompetence and aneurysm of the ascending aorta, J T h0
`rac Cardiovasc Surg 1992; 103(4): 617—21) described a
`surgical technique Where the dilated aortic root is replaced
`With a tube made of DACRON ?bres and the native aortic
`valve is integrated Within the graft. This method is generally
`knoWn as the “Tirone David Type I aortic valve sparing
`procedure”. HoWever, the lack of sinuses in a straight tube
`graft Was found to negatively in?uence proper valve
`function, With the consequent risk of decreasing valva
`longevity (KunZelman K. S., Grande K. J., David T. E.,
`Cochran R. P., Verrier E. D. : Aortic root and valve rela
`tionships. Impact on surgical repair J Thorac Cardiovascu
`lar Surg 1995; 109(2): 345—51).
`Thus in the Tirone David Type I technique for valve
`sparing operations, the use of a straight tube Without a sinus
`component raises several problems: opening and closing of
`the native valve is not optimal. For example, upon valve
`opening, the lea?ets might impact on the graft and be
`potentially damaged. The absence or delay in eddy current
`formation might alter valve closure causing some regurgi
`tation. Furthermore, the diastolic stress is borne only by the
`lea?et and is not shared With the sinuses causing a potential
`decrease in lea?et longevity.
`An optimal design for root replacement should therefore
`incorporate sinuses and a sinotubular junction and further
`re?nement of the technique consisted of trimming one end
`of the aortic tube graft to produce three separate extensions
`designed to replace the three sinuses. The reshaped
`DACRON tube Was then sutured to the aortic valve rem
`nants (see David T. E., Feindel C. M., Bos J.: Repair of the
`aortic valve in patients With aortic insuf?ciency and aortic
`root aneurysm. J Thorac Cardiovasc Surg 1995; 109(2)
`:345—51) to obtain a ?nal con?guration resembling more
`closely the native aortic root. A similar technique Was also
`described by Yacoub el al (Saram M. A., Yacoub M.:
`Remodeling of the aortic valve annulus. J T horac Cardio
`vasc Surg 1993; 105(3): 435—8) several years previously.
`In US. Pat. No. 5,139,515 it Was proposed to provide an
`aortic graft having a loWer portions provided With “bulges”
`apparently mimicking the sinuses of Valsalva. HoWever no
`method to produce such a conduit for use in aortic surgery
`is described in the patent. US. Pat. No. 5,139,515 described
`a conduit having an “annular Wall of a crimped material
`similar to that of conventional prosthesis”. No indication is
`actually given of hoW to obtain the “annularly-spaced radi
`ally outWard bulges” mimicking the sinuses. Moreover the
`draWings clearly shoW that the conduit, including the sinus
`portion, is provided along its Whole length With corrugations
`Which lie perpendicularly to the longitudinal aXis of the
`prosethesis, and Which impart longitudinal elasticity to the
`Whole of the conduit. Upon implantation, the graft cannot
`
`The normal internal human aortic root conduit is provided
`With a sinus portion Which has three sinuses (bulges) Which
`surround the aortic valve. These sinuses are called sinuses of
`Valsalva and are arranged so that the cross-section of the
`sinus portion has a generally trefoil shape. The diameter and
`ori?ce area of the root are greater at the level of the sinus,
`decrease slightly at the base, but signi?cantly decrease (by
`20%) at the level of the sinotubular junction (Where the sinus
`portion connects to the ascending portion of the aorta Which
`supports the tWo iliac arteries).
`The sinotubular junction or sinus ridge and the sinuses of
`Valsalva are knoWn to be crucial for the normal function of
`the aortic valve. The sinus ridge is important in causing
`initial ?uid ?oW eddies inside the sinuses of Valsalva (see
`Bellhouse B J: Velocity and pressure distributions in the
`aortic valve. J Fluid Mech 1969; 37(3): 587—600 and Bell
`house B. J.: The ?uid mechanics of the aortic valve. In:
`Ionescu M. L. , Ross D. N., Woller G. H., eds. Biological
`tissue heart replacement. London: ButterWorth-Heinemann,
`1972:32—8). During systole, the aortic valve opens and the
`eddy currents created prevent the lea?ets of the aortic valve
`from impacting on the aortic Wall. Then, at the end of
`systole, the eddy currents inside the sinuses cause the lea?ets
`of the aortic valve to become almost closed. Furthermore,
`the sinus curvature is very important in sharing stress With
`the lea?et. It has been demonstrated that during diastole the
`sinus Walls move outWardly (increasing its circumferential
`curvature by 16%) taking up part of the load placed on the
`lea?et. Further it is knoWn (see (Thubrikar M. J ., Nolan S.
`P., Aouad J ., Deck D.; Stress sharing betWeen the sinus and
`lea?ets of canine aortic valve. Ann T horac Surg 1986;
`42(4):434—40)) that the longitudinal length of the sinus
`changes very little or does not change at all during the
`cardiac cycle. In other Words during the functioning of the
`aortic valve the sinus moves up and doWn as a Whole Without
`changing its length.
`The standard surgical approach in patients With ascending
`aortic aneurysm or dissection involving the aortic root and
`associated With aortic valve disease is the replacement of the
`aortic valve and ascending aorta by means of a composite
`and valved graft onto Which are reattached the tWo coronary
`arteries as originally described by Bentall and de Bono in
`their classical paper (Bentall H. H., De Bono A.: Atechnique
`for complete replacement of the ascending aorta, Thorax
`1968; 23: 338—9). The “open” (Carrel button) method of
`coronary reimplantation Was later recommended to decrease
`the tension on the coronary ostia While minimiZing the risk
`of late false aneurysm formation. This “Carrel button”
`method has already reduced the incidence of pseudoaneu
`rysm formation mainly through the reduction of the tension
`on the ostial anastomoses (see Svensson L. G.; CraWford E.
`S.; Hess K. R.; Coselli J. S.; Sa? H. 1.; Composite valve graft
`replacement of the proXimal aorta: comparison of techniques
`in 348 patients. Ann Thorac Surg 1992, 54(3) 427—370). A
`
`15
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`US 6,352,554 B2
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`3
`expand radially outwardly, but has the potential to move and
`extend in the longitudinal direction of the longitudinal axis
`of the prosthesis.
`Therefore there is still a need for an effective prosthetic
`conduit to replace the aortic root While providing all the
`advantages of the natural sinuses of Valsalva.
`
`SUMMARY OF THE INVENTION
`
`It is therefore one of the objects of the invention to
`provide a prosthetic aortic conduit Which overcomes the
`drawbacks mentioned above and Which upon implantation
`has the ability to expand radially outWardly Whilst main
`taining a degree of ?exibility in the longitudinal direction.
`It is another object of the invention to provide a conduit
`Which is speci?cally designed to closely mimic the sinuses
`of Valsalva.
`A?rst object of the invention is a prosthetic aortic conduit
`for replacing a root portion of an aorta Which comprises a
`?rst tubular portion and a second tubular portion connected
`together along a substantially common axis. The second
`tubular portion does not substantially deform in a longitu
`dinal direction and has resilient means Which alloW said
`second portion to be expandable in a lateral direction. As the
`second portion is able to deform laterally it is able to mimic
`the function of the sinuses of Valsalva.
`It is preferred that the ?rst tubular portion of the prosthetic
`aortic conduit of the invention be provided With resilient
`means Which alloW expansion of said ?rst portion in a
`longitudinal direction.
`It is also preferred that the prosthetic aortic conduit be
`made of polyester or PTFE material, including expanded
`PTFE material Which may optionally be coated. Apreferred
`material is DACRON.
`It is further preferred that the second portion resilient
`means comprises longitudinally extending corrugations.
`It is further preferred that the ?rst portion resilient means
`of the conduit of the invention comprises annular corruga
`tions successively provided along the longitudinal axis of
`said conduit.
`It is further preferred that the ?rst and second portions of
`the conduit be made of tWo distinct tubes Which are secured
`together along said common axis.
`It is further preferred that the conduit is provided With a
`third tubular portion Which is connected to the second
`portion along the substantially common axis of the conduit.
`Advantageously this third tubular portion is provided With
`resilient means Which alloWs expansion of said third portion
`in a longitudinal direction.
`Optionally the conduit of the invention may be further
`provided With a prosthetic valve.
`Another object of the invention is a method of manufac
`turing a prosthetic aortic conduit as described above. This
`method comprises the folloWing steps:
`a) providing a ?rst tubular conduit suitable for use in heart
`surgery, the ?rst conduit having a longitudinal axis and
`?rst resilient means alloWing some expansion in the
`longitudinal direction only; and
`b) securing to one of the ends of this ?rst conduit a second
`tubular conduit suitable for use in heart surgery so that
`the lumens of the ?rst and second conduits are aligned
`and are continuous, the second conduit having a lon
`gitudinal axis and second resilient means Which alloWs
`some expansion in the lateral direction only.
`It is preferred that the ?rst resilient means comprises a
`plurality of annular corrugations successively provided
`
`10
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`along the longitudinal axis of the ?rst conduit and that the
`second resilient means comprises a plurality of longitudi
`nally extending corrugations successively provided around
`the circumference of the second conduit.
`It is also preferred that the second tubular conduit be made
`according to folloWing steps:
`a) taking a tubular conduit suitable for use in heart
`surgery, such conduit having annular corrugations
`alloWing some expansion in the longitudinal direction
`only and having tWo opposite ends; and
`b) cutting said tubular conduit from end to end; and
`c) aligning and securing the tWo opposite ends together to
`obtain said second tubular conduit.
`Where a third tubular conduit is required, this Will simply
`be attached to the end of the second conduit Which is not
`attached or not intended for attachment to the ?rst conduit.
`Again the lumen of the third conduit should be commonly
`aligned With that of the second conduit. Optionally the third
`conduit may be attached to the combination of the ?rst and
`second conduits. Alternatively the third conduit may be
`attached to the second conduit and then the ?rst conduit
`attached. As described above, the third conduit Will have
`circumferentially extending corrugations so Will be similar
`to the ?rst conduit in construction, but Will generally be of
`a shorter length.
`It is further preferred that the ?rst, second and third
`tubular conduits are made of DACRON or PTFE material.
`
`DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 is a representation of a knoWn aortic conduit,
`shoWing corrugations Which lie traverse to the longitudinal
`axis of the prosthesis;
`FIG. 2 is a prosthetic aortic conduit according to a ?rst
`preferred embodiment of the invention.
`FIG. 2a is a prosthetic aortic conduit according to a
`second preferred embodiment of the invention.
`FIGS. 3 and 4 are schematic vieWs of successive steps of
`manufacturing the aortic conduit shoWn in FIGS. 2 or 2a
`(included in a preferred method of the invention);
`FIG. 5 is the embodiment of the aortic conduit shoWn in
`FIGS. 2 or 2a Where the conduit has a prosthetic valve
`mounted thereon and is suitable for the Bentall type proce
`dure;
`FIG. 6 schematically represents the prosthetic aortic con
`duit of FIG. 2 during use in a Tirone David Type I Aortic
`Valve Sparing Procedure.
`
`DESCRIPTION OF PREFERRED
`EMBODIMENTS OF THE INVENTION
`
`FIG. 1 shoWs a standard aortic conduit 1 of the type
`currently used in aortic surgery. This conduit is made of
`DACRON but any suitable biocompatible material such as
`polytetra?uoroethylene (PTFE) could be used. This standard
`aortic conduit 1 includes circumferentially extending pleats
`so that the corrugations lie perpendicular to the longitudinal
`axis of the prosthesis. These corrugations provide a degree
`of expansion in the longitudinal direction (indicated by the
`black arroWs 3 in FIG. 1) and the conduit 1 can therefore
`signi?cantly increase its length.
`FIG. 2 shoWs a preferred embodiment of the conduit of
`the invention. The conduit 10 comprises tWo distinct tubular
`portions having a common axis. The ?rst upper portion 12
`is made from a standard aortic conduit similar to the one
`shoWn in FIG. 1 and is provided With circumferentially
`extending corrugations 13 successively provided along the
`
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`US 6,352,554 B2
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`5
`axis of the tubular ?rst portion 12. The second lower portion,
`or skirt portion, 14 is a tube Which can be made of the same
`material as the ?rst portion (that is, any suitable biocom
`patible material, but preferably DACRON or PTFE) but
`Which is provided With longitudinally extending pleats or
`corrugations 16. Each of these corrugations 16 extends in the
`general direction of the longitudinal axis of the prosthesis
`and is positioned substantially perpendicularly to the cir
`cumferential corrugations 13 of the ?rst portion 12.
`The proximal end of skirt portion 14 is attached to the
`distal end portion of the ?rst portion 12 so the tWo connected
`portions have essentially the same lumen and form the
`tubular conduit 10.
`The connection 28 betWeen the ?rst portion 12 and the
`skirt portion 14 (With their respective corrugations 13 and 16
`orientated at an angle of about 90°) Will act, upon
`implantation, as a “sinotubular junction” since its internal
`diameter Will be signi?cantly less than the internal diameter
`of its loWer part, namely second portion 14. Once the
`prosthetic aortic conduit 10 is in place the internal diameter
`of the skirt portion 14 Will vary during the cardiac cycle
`(systole/diastole) as in the natural aortic root. Thus, the skirt
`portion 14, When ?lled With blood under pressure, Will
`stretch in the direction traverse to the longitudinal axis of the
`prosthesis (the lateral direction) mimicking the “sinuses of
`Valsalva”. The pleat arrangement in skirt portion 14 does not
`hoWever alloW that section of the prosthesis to increase in
`length.
`Thus the skirt portion 14 can move and expand in a lateral
`direction only, While the ?rst portion 12 of the conduit 10
`can extend in the longitudinal direction only. The resiliency
`of the skirt portion 14 in the general lateral direction is
`shoWn in FIG. 2 by the arroWs 18 and the expansion of the
`?rst portion 12 in the general longitudinal direction is shoWn
`by the arroWs 20.
`In an alternative embodiment shoWn in FIG. 2a, a third
`tubular portion 15 is attached to the distal end of the skirt
`portion 14. The third tubular portion 15 is aligned on the
`same common axis as the ?rst and second portions 12 and
`14. The third portion 15 is aligned on the same common axis
`as the ?rst and second portions 12 and 14. The third portion
`15 is advantageously a short piece of standard aortic conduit,
`similar to that shoWn in FIG. 1. It is typically made of
`DACRON or similar material and is provided With circum
`ferentially extending corrugations or pleats 17 in the same
`manner as the ?rst portion 12.
`Generally, the length of the third portion 15 Will be short
`compared to the length of the ?rst and second portions 12
`and 14 and the presence of tWo or three corrugations 17 in
`the third portion 15 Will normally be suf?cient.
`PREFERRED METHOD OF MANUFACTURE
`OF A CONDUIT ACCORDING TO THE
`INVENTION
`The conduit 10 may be either manufactured indepen
`dently or obtained according to the folloWing method Which
`is a further preferred embodiment of the invention and
`Which is described With reference to FIGS. 3 and 4.
`First, to obtain a skirt portion 14 like the one shoWn in
`FIGS. 2 or 2a a portion of a standard tube 14a (see FIG. 3)
`having annular corrugations provided along its axis is cut
`open from end to end as shoWn in FIG. 3. Preferably the
`material chosen Will be DACRON. The tube 14a has a
`diameter approximately equal to the desired ?nal length of
`skirt portion 14. Also, the length of tube 14a is chosen to
`correspond to the desired diameter of the skirt portion 14.
`Once tube 14a has been cut open, the tWo end ridges 22
`and 24 of the tube 14a are secured together (for example by
`suture) as shoWn in FIG. 4 and a skirt portion 14 is thus
`obtained.
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`A standard annularly corrugated tube, also preferably
`made of DACRON or similar material, is then provided to
`form the ?rst portion 12 and the tWo portions 12 and 14 of
`the aortic conduit according to the invention are then
`secured together. As shoWn in FIG. 2 Which relates to the
`?rst preferred embodiment of the invention, the tWo portions
`12 and 14 may be sutured together using a thread 26.
`It should be noted that While making the conduit 10 the
`length of the skirt portion 14 should be long enough to be
`trimmed according to the patient anatomy in aortic valve
`sparing operations.
`The conduit 10‘ shoWn in FIG. 2a can be made by
`securing a third tubular portion 15 to the distal end of the
`skirt 14 of a conduit 10 shoWn in FIG. 2 and made as above.
`This third portion 15 is preferably made of a small tubular
`section of a standard tube having annular corrugations
`provided along its axis (as in FIG. 1). The proximal end of
`the small tubular section is then secured to the distal end of
`skirt portion 14 by knoWn methods, for example by suture.
`Aortic conduits of the invention may be used and adapted
`to various surgical techniques knoWn to those skilled in the
`art, including those being described in detail beloW.
`
`1. Composite Valve Graft Replacement (Bentall
`Operation)
`The use of the aortic conduit of the invention does not
`require any changes in this knoWn standard surgical tech
`nique.
`FIG. 5 shoWs the conduit 10‘ of FIG. 2a adapted for the
`Bentall Operation. A standard bilea?et prosthetic valve 32
`Which is positioned partially inside the skirt portion 14. The
`prosthesis includes the annularly corrugated third portion 15
`Which is secured at the distal end of the skirt portion 14. This
`third portion 15 is attached to the heart and the skirt portion
`14 mimics the sinuses of Valsalva. The coronary ostia are
`reattached to the conduit 10‘ either using the classical
`technique or the “open” technique (Carrel button) depending
`on the surgeon’s preference. The presence of the third
`portion 15 facilitates attachment of the arti?cial valve of the
`prosthesis Whilst the longitudinally corrugated skirt portion
`14 gives several advantages over a standard DACRON graft
`tube.
`The lateral resiliency of the skirt portion 14 reduces
`tension on the coronary ostia anastomoses not only during
`suturing but, most importantly, after the graft has been
`pressurised at the end of surgery. As a consequence, the
`modi?ed aortic conduit 10‘ is particularly advantageous for
`use in cases Where the coronary ostia are difficult to
`mobilise, dif?cult to reach (loW lying coronary ostia) or
`Where they are severely calci?ed.
`Furthermore, at the end of the procedure, any undue
`tension along the long axis of the conduit 10‘ , instead of
`being directly transmitted to the coronary anastomoses, Will
`be dampened by the sutures connecting the tWo portions of
`the conduit 10‘ as the skirt portion 14 of the conduit 10‘ (the
`neW aortic root) is pulled as a Whole.
`
`2. Tirone David type I
`
`A conduit according to the invention may also be used in
`classic “non-valved” aortic surgery knoWn as “Tirone David
`type 1”. The operation is carried out as originally described
`by David and Feindel in their previously mentioned paper
`and as knoWn in the art. FIG. 6 illustrates the use of conduit
`10 of FIG. 2 in the Tirone David type I procedure. Brie?y,
`the three sinuses of Valsalva are excised leaving 5 mm of
`arterial Wall attached to the patient’s aortic valve and around
`the tWo coronary ostia, and multiple horiZontal mattress
`sutures are passed beloW the aortic valve and then through
`
`Edwards Lifesciences Corporation, et al. Exhibit 1121, Page 11 of 13
`
`

`

`US 6,352,554 B2
`
`7
`the end of the aortic conduit 10. The conduit 10 is tailored
`so that the top of the three commissures 46, 48 and 50 Will
`correspond to the “neW sinotubular junction” (i.e. the junc
`tion 28 betWeen the ?rst portion 12 and the skirt portion 14)
`or a feW mm above that junction 28. The ?rst portion 12 of
`the conduit 10 is then cut 2 or 3 cm above the sutures. Next,
`the valve is secured to the graft in a manner similar to that
`for implanting a free-hand, subcoronary homograft aortic
`valve. Finally, the coronary ostia are reimplanted onto the
`conduit 10.
`Once the conduit 10 is pressurised at the end of the
`surgical procedure, the loWer part of the tube (skirt portion
`14) Will expand circumferentially creating neW sinuses of
`Valsalva. The three commissures 46, 48 and 50, being ?xed
`to junction 28 of the ?rst portion 12 Which do not expand
`circumferentially, Will maintain their correct spacing and
`orientation (see FIG. 6). The presence of a neW sinotubular
`junction and of arti?cial sinuses of Valsalva Will ensure the
`creation of eddy currents With a more physiological opening
`and closure of the valve lea?ets. Furthermore, the sinuses
`might have the potential of expanding circumferentially
`during the cardiac cycle With consequent reduced stress on
`the lea?et. The long term durability of the valve should
`therefore be greatly improved.
`The conduit 10‘ of FIG. 2a could alternatively be used for
`this procedure.
`
`Yacoub or Tirone David type II (or III)
`Similarly, for the application of this surgical technique,
`the operation is carried out as previously described in using
`the aortic conduit according to the invention described With
`reference to FIG. 2. Brie?y, the diseased aortic sinuses are
`excised doWn to the aortic annulus and an approximately
`siZed conduit according to the invention is chosen. The skirt
`portion 14 of the conduit 10 is trimmed to produce three
`separate extensions, properly spaced, that Will replace the
`sinuses. The height of the grooves is made so to reach the
`“neW sinotubular junction ” 28 of FIG. 2 or feW mm above.
`Next, the top of the three commissures are ?xed to the apex
`of each groove in a proper orientation. The excess of the
`conduit 10 is trimmed to precisely ?t each sinus once it is
`sutured to the aortic annulus. Establishing the right length of
`the three extensions is facilitated because the skirt portion 14
`does not stretch in the longitudinal direction. Finally, each
`extension is sutured to the remnants of arterial Wall and
`aortic annulus surrounding the sinuses and then the coronary
`ostia are reimplanted onto the graft.
`Compared to the standard DACRON graft tube, the use of
`the conduit of the invention offers the potential for a reduced
`tension on the coronary ostia anastomoses, an optimised
`circumferential expansion of the three sinuses With better
`stress sharing betWeen the lea?et and the arti?cial sinus Wall.
`The sinotubular junction is Well de?ned and the maintenance
`of a good lea?ets coaptation is assured by ?xation of the top
`of each commissure to the portion of graft that does not
`expand circumferentially.
`The prosthetic aortic conduit according to the invention is
`speci?cally designed to potentially ?t all types of surgical
`operations above mentioned that are currently performed to
`treat pathologies of the aortic value and the aortic root.
`I claim:
`1. A prosthetic aortic conduit for replacing a root portion
`of an aorta, said conduit having ?rst and second ends,
`Wherein said conduit comprises a ?rst tubular portion and a
`second tubular sinus portion connected together along a
`substantially common axis, Wherein the ?rst tubular portion
`forms the ?rst end of the conduit, Wherein said second sinus
`portion does not substantially deform in a longitudinal
`direction and has resilient means comprising longitudinally
`
`5
`
`20
`
`35
`
`45
`
`55
`
`65
`
`8
`extending corrugations Which alloW said second sinus por
`tion to be expandable in a later direction to mimic the
`function of the sinuses of Valsalva.
`2. The prosthetic aortic conduit of claim 1, Wherein said
`?rst portion is provided With resilient means Which alloW
`expansion of said ?rst portion in a longitudinal direction.
`3. The prosthetic aortic conduit of claim 1, Wherein said
`conduit is made of DACRON or PTFE material.
`4. The prosthetic aortic conduit of claim 3, Wherein the
`?rst and second portions are made of tWo distinct tubes
`Which are secured together along said common axis.
`5. The prosthetic aortic conduit of claim 3, Which is
`further provided With a prosthetic valve.
`6. The prosthetic aortic conduit of claim 1, Wherein said
`?rst portion resilient means comprises annular corrugations
`successively provided along the longitudinal axis of said
`?rst portion.
`7. The prosthetic aortic conduit of claim 1, Wherein a third
`tubular portion is connected to the second portion along said
`substantially common axis and Wherein said third tubular
`portion is provided With resilient means Which alloW expan
`sion of said third portion in a longitudinal direction.
`8. A method of manufacturing a prosthetic aortic conduit
`having ?rst and second ends, Which comprises the folloWing
`steps:
`a) providing a ?rst tubular conduit suitable for use in heart
`surgery, said ?rst conduit having a longitudinal axis and
`?rst resilient means alloWing some expansion in the
`longitudinal direction only; and
`b) securing to one of the ends of this ?rst conduit a second
`tubular sinus conduit suitable for use in heart surgery,
`said second sinus conduit having a circumference and
`second resilient means Which alloWs some expansion in
`the lateral direction only; so that the ?rst tubular
`portion forms the ?rst end of the prosthetic aortic
`conduit.
`9. The method of claim 8, Wherein the ?rst resilient means
`comprises a plurality of annular corrugations successively
`provided along the longitudinal axis of the ?rst conduit and
`Wherein the seco