`Neutral Citation Number: [2009] EWHC 1304 (Pat)
`
`
`IN THE HIGH COURT OF JUSTICE
`CHANCERY DIVISION
`PATENTS COURT
`
`
`Case No: HC08 C 00934
`
`Royal Courts of Justice
`Strand, London, WC2A 2LL
`
`Date: 12 June 2009
`
`Before :
`
`THE HONOURABLE MR JUSTICE KITCHIN
`- - - - - - - - - - - - - - - - - - - - -
`Between :
`
`EDWARDS LIFESCIENCES AG
`(a company incorporated under the laws of
`Switzerland)
`
`- and –
`
`COOK BIOTECH INCORPORATED (a company
`incorporated under the laws of the state of Indiana,
`USA)
`
`Claimant
`
`Defendant
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`Roger Wyand QC, Piers Acland and Miles Copeland (instructed by Bird & Bird) for the
`Claimant
`Simon Thorley QC and Adrian Speck (instructed by Marks & Clerk Solicitors) for the
`Defendant
`
`
`Hearing dates: 6-8, 11, 12, 14 and 15 May 2009
`- - - - - - - - - - - - - - - - - - - - -
`Approved Judgment
`I direct that pursuant to CPR PD 39A para 6.1 no official shorthand note shall be taken of this
`Judgment and that copies of this version as handed down may be treated as authentic.
`
`
`.............................
`
`MR JUSTICE KITCHIN
`
`
`
`
`
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`Edwards Lifesciences Corporation, et al. Exhibit 1038, p. 1 of 43
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`Mr Justice Kitchin :
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`1.
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`2.
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`3.
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`This is a patent action in which the Claimant (“Edwards”) seeks revocation of
`European Patent (UK) 1 255 510 (“the Patent”). The Defendant (“Cook”) is the
`proprietor of the Patent and has counterclaimed for infringement.
`
`Edwards manufactures the SAPIEN artificial heart valve which was launched in
`Europe in 2007. It is designed to be compressed onto a balloon catheter for
`percutaneous delivery via the femoral artery. It can also be delivered transapically
`through the side of the chest and into the apex (the bottom of the left ventricle) of the
`heart in patients with severe aortic stenosis. It is primarily used to replace the aortic
`valve but is also suitable for replacement of the pulmonary valve.
`
`Cook alleges the SAPIEN infringes the following claims of the Patent which are said
`to be independently valid: 1, 12, 15, 22, 23, 28 and 31. Edwards denies infringement
`and challenges the validity of these claims and claims 3 and 8 (which are also said to
`be independently valid but not infringed) on the following grounds:
`
`i)
`
`Lack of novelty under section 2(3) of the Patents Act 1977 (“the Act”) in the
`light of WO 01/19285 published on 22 March 2001 (“Thorpe”);
`
`ii)
`
`Obviousness in the light of:
`
`a)
`
`b)
`
`c)
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`d)
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`U.S. Patent 5,411,552 published on 2 May 1995 (“Andersen”);
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`EP 0 856 300 A1 published on 5 August 1988 (“Moll”);
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`“Aortic and venous valve for percutaneous insertion” by D. Pavcnik et
`al., published in 2000 (“Pavcnik”);
`
`common general knowledge.
`
`iii)
`
`iv)
`
`Insufficiency. Edwards contends the specification of the Patent does not
`disclose the alleged invention clearly enough or completely enough for it to be
`performed arising from the use in claim 1 of the word “substantially”.
`Essentially this is a question of the proper interpretation of the claim.
`
`Added matter. Edwards contends the matter disclosed in the specification of
`the Patent as granted has been extended over the original disclosure in the
`application for the Patent as filed. There are two aspects to the objection. One
`arises from the use in claim 1 of the word “substantially” and the other turns
`on the proper interpretation of claim 3.
`
`Witnesses
`
`Each of the parties called two expert witnesses, an interventional cardiologist and a
`bioengineer. On behalf of Edwards, I heard evidence from Dr Nigel Buller and Dr
`Rodolfo Quijano.
`
`Dr Buller is a consultant cardiologist in private practice. Until January 2008, he was
`Head of Interventional Cardiology at the Queen Elizabeth Hospital, Birmingham. The
`Queen Elizabeth has one of the leading cardiology departments in the UK and one of
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`4.
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`5.
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`Edwards Lifesciences Corporation, et al. Exhibit 1038, p. 2 of 43
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`6.
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`7.
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`8.
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`9.
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`10.
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`11.
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`only five centres that provide fully comprehensive adult cardiological services. Dr
`Buller has extensive experience of catheterization procedures, including balloon
`angioplasty and stent implantation and throughout his career has had a close working
`relationship with many of the major medical device manufacturers.
`
`Cook does not suggest I should reach a general conclusion adverse to Dr Buller but
`invites me to say that he may have lost total objectivity in a limited number of
`instances. I decline that invitation. Dr Buller was measured, careful and precise in
`expressing his opinions and I have found his evidence of great assistance.
`
`Dr Quijano has been involved in the design and development of biological and
`mechanical replacement heart and venous valves for more than 35 years. Cook makes
`no criticism of Dr Quijano, and rightly so. He clearly has a passion for and a deep
`understanding of the technical issues involved in the design of replacement cardiac
`and venous valves.
`
`On behalf of Cook, I heard evidence from Professor Martin Rothman and Professor
`David Williams.
`
`Professor Rothman is a consultant cardiologist and the Director of Cardiac Research
`& Development at Barts and the London NHS Trust and Honorary Professor of
`Interventional Cardiology at Queen Mary, University of London. Interventional
`cardiology has been the focus of Professor Rothman’s entire career and he is
`recognised as one of its pioneers. He has worked with cardiovascular stents since the
`early 1980s and over the years has advised many different companies operating in the
`pharmaceutical and medical device sectors in relation to a wide range of devices used
`in conjunction with interventional cardiology.
`
`Edwards accepts that Professor Rothman is a skilled and expert cardiologist but
`contends his evidence was partisan, as illustrated by a marked shift in his opinions
`from those he held in an earlier case between Edwards and a company called
`CoreValve. I think it fair to say the opinions expressed by Professor Rothman in his
`reports in the two cases are indeed different in material respects and this formed the
`basis of a good deal of his cross examination. However, as Cook submits, opinions
`may change in the course of a case, particularly after cross examination, and I accept
`that in formulating his reports in this case Professor Rothman may have given further
`consideration to the abilities of the ordinary skilled person. Importantly, I believe
`Professor Rothman answered the questions put to him fairly and frankly and I found
`his opinions cogent and reasonable.
`
`Professor Williams is currently Professor and Director of International Affairs at the
`Wake Forest Institute of Regenerative Medicine in North Carolina. He is also
`Visiting Professor in the Christiaan Barnard Department of Cardiothoracic Surgery at
`the University of Cape Town. His career over the last forty years has been devoted to
`the fields of bioengineering, biomaterials science and regenerative medicine. Among
`his many activities he has been directly concerned with the development of new
`materials for use in surgically implantable heart valves.
`
`12.
`
`Edwards says Professor Williams did not seem to appreciate the role of the skilled
`person in his approach to the prior art and appeared reluctant to attempt to correct
`
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`Edwards Lifesciences Corporation, et al. Exhibit 1038, p. 3 of 43
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`13.
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`deficiencies so as to make it work. I reject this criticism. I found Professor Williams
`to be careful and fair in addressing the questions put to him.
`
`Edwards also adduced evidence of fact from Mr Stanton Rowe, an employee of
`Edwards, who was involved in the development of the SAPIEN. Mr Rowe’s evidence
`was directed to the suggestion made by Professor Rothman in his first report that it
`took ten years of research to develop the ideas described in Andersen into the
`SAPIEN. He was not cross examined and his evidence ultimately played no real part
`in the matters I have to decide.
`
` The skilled person
`
`14.
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`15.
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`16.
`
`There was little between the parties as to the identity of those persons to whom the
`Patent is addressed. Professor Rothman and Professor Williams considered the Patent
`is directed towards a skilled team comprising an interventional cardiologist (in so far
`as it concerns heart valves) or a general vascular surgeon (in so far as it concerns vein
`valves) and, in either case, a bioengineer. Professor Rothman considered the team
`might also consult a cardiac surgeon in order to find out about contemporary work
`with surgically implantable replacement heart valves. Professor Williams elaborated,
`and I accept, that in practice a number of engineers might be involved in the team,
`depending on their specific areas of expertise. For example, one might have
`particular experience of stent design, another experience of the design of cardiac
`valve replacements and a third experience of biomaterials. He too considered that a
`cardiac surgeon would be involved in order to provide experience of some of the
`practical problems encountered in using surgically implantable valves.
`
`Dr Buller believed that the team would have included an interventional cardiologist
`and a medical device designer familiar with the design of stents and implantable
`valves and the materials used to make them.
`
`In the light of all this evidence I am content to adopt the formulation of the skilled
`team propounded by Professor Rothman and Professor Williams, subject to the
`following qualification. I am entirely satisfied that the team would have contained or
`at least consulted with a person familiar with the design of implantable surgical heart
`valves.
`
` Common general knowledge
`
`17.
`
`There was no real dispute as to much of the common general knowledge and the
`following description is drawn largely from the reports of the experts.
`
`The cardiovascular system
`
`18.
`
`The cardiovascular system is divided into the pulmonary circulation which supplies
`blood to the lungs and the systemic circulation which supplies blood to the rest of the
`body. The heart lies at the centre of the system. It pumps blood through the blood
`vessels by repeated rhythmic contractions and it consists of four chambers, two atria
`and two ventricles, as shown in the diagram below:
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`
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`Edwards Lifesciences Corporation, et al. Exhibit 1038, p. 4 of 43
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`19.
`An enlarged section of the aortic valve may be represented like this:
`
`
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`20.
`De-oxygenated blood from the body is collected in the right atrium, passes through
`the tricuspid valve into the right ventricle and is then pumped through the pulmonary
`artery into the lungs where carbon dioxide is removed and oxygen absorbed. As the
`right ventricle contracts, the tricuspid valve closes, ensuring that blood is not injected
`back into the right atrium. At the same time the pulmonary valve opens allowing the
`blood to flow from the right ventricle into the pulmonary artery.
`
`Blood returns to the heart from the lungs through the pulmonary vein and it collects in
`the left atrium. From the left atrium the blood flows to the left ventricle through the
`mitral valve. When the left ventricle contracts, the mitral valve closes, the aortic
`valve opens and the blood is duly pumped through the aorta to the body. The
`pulmonary valve and aortic valve prevent blood returning to the ventricles from the
`pulmonary artery and aorta respectively.
`
`The enlarged section of the diagram of the heart set out above depicts the arrangement
`of the aortic valve, a matter of particular importance in this case. The aortic valve sits
`in the aortic valve annulus, a fibrous ring at the junction between the left ventricle and
`
`21.
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`22.
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`Edwards Lifesciences Corporation, et al. Exhibit 1038, p. 5 of 43
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`23.
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`the aorta immediately below the sinuses. The aortic valve itself has three leaflets (or
`cusps) which are half moon shaped. As mentioned, when the left ventricle contracts,
`the pressure inside the ventricle increases until it is greater than in the aorta, at which
`point the aortic valve opens. When the ventricular contraction ends, pressure in the
`left ventricle rapidly drops. When it falls below the pressure in the aorta, the leaflets
`of the aortic valve collapse and come together along their edges (commissures) and
`flow of blood from the aorta back to the heart is prevented. Sitting within the aortic
`sinuses and within a few millimetres of the leaflets are the coronary ostia, which are
`openings that lead to the coronary arteries. It is crucial that these are not blocked
`when a valve is replaced because the coronary arteries provide the heart muscle with
`blood.
`
`Veins in the limbs also have valves, called venous valves, which prevent blood
`flowing backwards and pooling in the extremities due to the effects of gravity.
`Venous valves have two leaflets. Replacement of faulty veins and venous valves has
`been the subject of much experimentation, but is not yet done routinely in clinical
`practice with treatment primarily centering on removal of abnormal veins or systemic
`treatment with anticoagulants. As Professor Rothman explained, there has been little
`commercial or clinical incentive to develop replacement vein valves and such
`development
`that
`there has been has
`lagged behind
`the development of
`percutaneously delivered heart valves.
`
`Cardiac surgery and prosthetic valves
`
`24.
`
`Surgeons have been replacing diseased or malfunctioning heart valves for over 40
`years. They have used for this purpose a range of prosthetic valves, both mechanical
`and biological.
`
`25. Mechanical replacement heart valves are generally made from a combination of
`metal, carbon and plastic and typically provide a valve function through a tilting disc
`or a ball moving within a cage. They have a long life span but patients suffer an
`increased risk of thrombus formation which requires them to undergo life-long
`anticoagulation therapy.
`
`Biologically derived (bioprosthetic) valves attempt to replicate more closely the
`structure and dynamics of a physiological heart valve. They are made of tissue,
`generally mounted on a textile cuff or metallic or plastic frame and fall into three
`categories: homograft (human whole valves), xenograft (animal whole valves) and
`fabricated (valves tailored from animal pericardium, the tissue that covers the outside
`of the heart). The latter two categories are those of most importance in the context of
`the present case.
`
`Xenograft valves are normally of porcine origin, but can also be of equine or bovine
`origin. The valve is physically removed from the animal and treated chemically in
`order to make the biological tissue immunologically inert and sterile and to improve
`its mechanical properties. It is then attached to a textile cuff allowing it to be sutured
`to the heart tissue or mounted on a frame which provides some mechanical support.
`Such a frame is usually referred to as a stent. In 2000, a well established bioprosthetic
`valve using a porcine valve was called the “Hancock”. In this device the valve is
`fixed to a non-collapsible stent covered with fabric, allowing it to be sutured into the
`patient around its circumference. The valve has three leaflets which, when the valve
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`26.
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`27.
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`Edwards Lifesciences Corporation, et al. Exhibit 1038, p. 6 of 43
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`28.
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`is closed, meet at their free margins, that is to say the edges which are free to move
`from the centre of the valve towards the circumference of the valve when opening and
`free to return to the centre when closing. The line at which any two of these free edges
`meet is referred to as the commissure or line of coaption.
`
`In the case of fabricated valves, leaflets, normally three in number, are fashioned from
`a sheet of pericardium and again attached to a frame and sewing cuff. In 2000, one of
`the most successful fabricated bioprosthetic heart valves was the “Carpentier-Edwards
`pericardial aortic prosthesis”, also known as the “Perimount”. It was implanted as
`early as 1980 in France and approved for use in the US in 1991. It looks like this:
`
`
`
`29.
`Like the Hancock, the Perimount comprises a non-collapsible stent, covered with
`fabric, which provides a means to suture it into the patient. The stent has three
`projecting portions known as commissural posts to which the leaflets are connected at
`the periphery of their commissures. The leaflets are also sutured to the fabric covered
`stent along the entirety of the inflow side of the valve (the margin of attachment) to
`preserve the valvular mechanism geometry and ensure the valve does not leak
`peripherally.
`
`Pericardium is the only natural tissue that has ever been used commercially to
`fabricate a bioprosthetic valve. Its advantages are numerous. It is available in
`relatively large quantities, permits the production of leaflets that have uniform
`thickness, strength and flexibility, can be cut to any desired size and, after suitable
`chemical treatment, possesses physical properties that closely resemble those of the
`leaflets of human valves. Moreover, pericardium is biocompatible and exhibits low
`thrombogenicity. For all these reasons, for many years before 2000, pericardium was
`the only tissue used for the production of commercialised fabricated bioprosthetic
`valves. However, such valves do suffer from the drawback that they have a tendency
`to denature or calcify, which affects their long term performance.
`
`As Professor Williams explained, by 2000, attempts had been made to develop a
`surgically implantable polymer leaflet heart valve which was seen as having the
`potential to avoid the difficulties of thrombosis caused by the mechanical valves and
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`30.
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`31.
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`Edwards Lifesciences Corporation, et al. Exhibit 1038, p. 7 of 43
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`calcification which tends to occur with bioprosthetic valves. However, no
`commercial polymer leaflet surgical valves existed at that time.
`
`Interventional cardiology
`
`32.
`
`33.
`
`Surgical heart valve replacement involves a major operation and is not suitable for all
`patients. However, from the 1960s a new branch of medicine emerged known as
`interventional cardiology. This is the practice of percutaneously treating problems
`within the heart and associated vessels and is the province of physicians rather than
`surgeons. Interventional procedures are carried out using a catheter to access the site
`in the heart or vasculature where the intervention is to be performed.
`
`As Professor Rothman elaborated, in 1977, Andreas Gruentzig performed the first
`human balloon angioplasty procedure in which a catheter carrying a balloon was
`inserted into an occluded human coronary artery and then expanded to force the artery
`open. By 1990, balloon angioplasty and two related techniques called valvuloplasty
`(using inflation of a balloon catheter to try to open up a stenotic (narrowed) heart
`valve and improve blood flow) and atherectomy (using a high speed rotating device or
`a directional slicing device to remove plaque from the inside of an artery) were
`regularly being undertaken.
`
`34. Most interventional cardiology is performed percutaneously using a needle inserted
`into the femoral or radial artery. But it is also possible to cut through the skin over
`the vessel using a procedure known as “cut-down”. Once access to the artery is
`secured, the catheter is passed to the heart against the blood flow in what is known as
`a “retrograde” approach. Access to the heart can also be achieved by means of an
`“antegrade” approach, that is to say passing the catheter in the same direction as the
`blood flow. In this case the catheter is introduced into a peripheral vein and then
`advanced along the vena cava to the right side of the heart. If access to the left side of
`the heart is required then the catheter must be fed through the wall (called the septum)
`which lies between the two atria of the heart. This technique is used to perform mitral
`valvuloplasty.
`
`In the course of the 1980s and 1990s a great deal of work was also being carried out
`into the design of expandable stents for translumenal implantation. These were
`developed to scaffold the internal surface of an artery, initially to prevent an acute
`closure at the time of a balloon angioplasty procedure, particularly of the coronary
`artery. However, in the 1990s two major randomised trials known as Benestent and
`Stress showed that the use of stents also resulted in reduced occurrence of re-
`narrowing (restenosis) compared with patients receiving balloon angioplasty. As a
`result, by 2000, stents were being used electively with balloon angioplasty in the
`majority of cases. They also allowed interventional cardiologists to attempt
`angioplasty in higher risk and more diseased vessels because they knew that stents
`had the capacity to prevent short-term and long-term complications.
`
`Stents essentially fall into two categories, those which are balloon expandable and
`those which are self-expanding. Balloon expandable stents are compressed around a
`balloon and inserted into a peripheral vessel by catheter. Once the balloon
`expandable stent reaches its destination the balloon is expanded to force open the
`stent by plastic deformation. The balloon is then deflated and the catheter withdrawn.
`Some, like the Palmaz-Schatz had a slotted tube design:
`
`35.
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`36.
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`Edwards Lifesciences Corporation, et al. Exhibit 1038, p. 8 of 43
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`37.
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`Others, such as the Gianturco-Roubin had an expandable wire coil design:
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`38.
`Self-expanding stents are made of a spring or of a “memory metal” such as nitinol.
`These require a sheath to maintain the stent in its compressed form during delivery.
`Once the stent reaches its desired location the sheath is withdrawn and the stent
`expands. One of the first self-expanding stents was the Gianturco Z-stent, which was
`first used in the mid-1980s. It has a “zigzag” design and, in a later modification,
`multiple zigzags were joined together by metal struts or monofilament line to provide
`a greater degree of stability:
`
`
`
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`39.
`By January 2000, many devices consisted of a number of rings joined together and
`those in the art tended to describe the whole of any such device as a single stent,
`irrespective of how many rings it might contain.
`
`40.
`
`Clearly, stents of different lengths and diameters may be required for different
`applications. By 2000, it was the general practice to “size” the stent to a diameter
`approximately 10 to 20% greater than the normal diameter of the treated vessel so as
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`Edwards Lifesciences Corporation, et al. Exhibit 1038, p. 9 of 43
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`41.
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`to ensure it would remain in place once deployed and leave the lumen of the vessel
`unobstructed.
`
`Finally, I should mention that for many years prior to 2000 sheaths had been used to
`cover or contain stents prior to deployment. It was also well known to cover the
`outside of stents with bio-compatible material such as Dacron, for example to create
`stent grafts used to support or isolate a weak portion in a vessel, such as an arterial
`aneurysm.
`
`The Patent
`
`The Patent opens with a description of the “Technical field of the invention”. It states
`that the invention includes a medical device and, more specifically, a valve found
`generally within a frame which, in preferred devices, comprises a radially expandable
`stent which can be delivered through a delivery device such as a catheter.
`
`Paragraph [0002] explains that the closest prior art is EP-A-0808614 (the “614
`application”) which, it is said, discloses the preamble to claim 1. The 614 application
`relates to a self-expandable stent with a tri-leaflet or bi-leaflet valve member,
`preferably “made of parts from living organisms such as a valve from a pig or a
`pericardium from a cow”.
`
`The “Background of the invention” is set out from paragraphs [0003] to [0007]. Two
`types of known replacement valves are described: mechanical devices with moving
`ball valves which are susceptible to clot formation and problems associated with long-
`term wear and tear; and biological valves which suffer from a variety of problems
`including the supply of valves, immune response and problems associated with
`positioning. The Patent explains there is therefore a need for alternative and
`improved devices and methods of providing valvular function within vessels of the
`body.
`
`Paragraph [0008] contains a “Summary of the Invention”. It discloses a medical
`device comprising a frame with a valve located within it. The frame comprises a
`radially-expandable stent (including especially a self-expanding stent) which can be
`delivered using a catheter and then deployed and expanded at a target site in a body
`lumen such as an artery or vein. A preferred use is for the treatment of incompetent
`veins in the legs or feet.
`
`There then follows a “Detailed description of the invention”. Paragraph [0010]
`explains that a valve assembly may have two or more leaflets or cusps. The structure
`of a typical stent of the invention is depicted in figures 1-3 and described in
`paragraphs [0011] to [0013]. One embodiment is said to be a self-expanding stent
`such as the Gianturco and the figures depict a simple arrangement of a cylinder
`formed by a wire bent or otherwise formed into a zigzag configuration. The
`specification explains that the bends at the proximal and distal ends of the stent may
`be connected by sutures which can be used to adjust the size of the stent lumen upon
`expansion.
`
`Paragraphs [0014] to [0017] explain how the valve may be fashioned from a sheet of
`valve material draped over the stent lumen and then pushed down into its interior.
`According to the invention, the valve material is said to be a collagen containing bio-
`
`42.
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`43.
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`44.
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`45.
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`46.
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`47.
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`Edwards Lifesciences Corporation, et al. Exhibit 1038, p. 10 of 43
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`material comprising pericardium which is then fixed to the stent frame by a variety of
`well known means including sutures, adhesives and folds. Connection of the valve to
`the frame is shown in figures 6A and 6B and the Patent explains that it may be
`sutured at its distal and proximal ends.
`
`48.
`
`Paragraph [0018] relates that once the sutures are generally in place, the valve sheet
`will form a valve pocket, as shown in figure 6B:
`
`
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`49.
`The pocket has a valve apex (50) which extends inside the stent lumen and may be
`sutured to the distal end of the stent frame. There is a part of the valve that will form
`a central valve portion (49) that is not directly sutured to the stent, but otherwise the
`valve is sutured around its proximal perimeter to the proximal end of the stent. The
`valve portion (49) forms the valve opening (52) through which fluid can pass as it
`flows from the distal to the proximal end of the device. However, if the flow is
`reversed then the valve pocket (46) fills and the fluid pressure causes the valve
`portion (49) to extend outwards and, when it does so, to contact the other leaflets or
`cusps and so form a seal to stop or impede fluid flow.
`
`50.
`
`Figure 8, reproduced below, illustrates the valve set in the stent with its distal apex
`(50) sewn to a distal bend of the stent with a suture (40). It also shows the proximal
`perimeter of the valve connected to the proximal portion of the stent with two sutures
`(44):
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`Edwards Lifesciences Corporation, et al. Exhibit 1038, p. 11 of 43
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`51.
`Paragraph [0021] continues that the valve opening is actually created in the final step
`of preparation of the preferred device. First, a second valve pocket is made by pushing
`the same sheet of valve material down into the interior on the other side of the stent.
`The two valve pockets are now sitting side by side. The opening can then be created
`by cutting a slit in the sheet which can be sized according to the intended flow rate of
`the passing fluid. The Patent also recognises that opening and closing the valve may
`cause increased wear and tear at the corners of the opening and, for this reason,
`reinforcements may be provided in the form of sutures, as illustrated at (53), or by the
`use of adhesives or any other material or mechanism that permits increased structural
`integrity. The Patent also explains in paragraph [0033] that the slit may terminate
`several millimetres (say 1 to 5 mm) before reaching the edge.
`
`52.
`
`There then follows a description of how the devices of the invention may be made to
`different sizes. Paragraph [0022] explains this may be achieved either by elongating
`the length of the struts of a single stent or by joining a number of stents together (by,
`for example, sutures). It is preferred that the overall length of the device provides an
`aspect ratio (length to expanded diameter) sufficiently high to permit proper
`alignment of the device and that aspect ratios of length to expanded diameter of 1:1 or
`greater are preferred. It is to be noted, however, that in devices comprising multiple
`stents there is no requirement that the individual stents should themselves be of any
`particular length. The teaching of the Patent is simply that the length of the whole
`device should be appropriate for its intended application and its aspect ratio should be
`such as to allow proper alignment.
`
`53.
`
`A variety of multiple stent structures are then described and depicted but some are
`said not to be part of the invention, a reflection of the citation by the examiner of the
`
`
`
`Edwards Lifesciences Corporation, et al. Exhibit 1038, p. 12 of 43
`
`

`

`
`
`
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`
`
`614 application. Thus figure 12, described in paragraph [0028], is said to be a multi-
`stent device of the invention:
`
`
`54.
`As is figure 17:
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`
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`
`
`
`
`
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`Edwards Lifesciences Corporation, et al. Exhibit 1038, p. 13 of 43
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`

`

`
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`
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`55.
`
`Conversely, figure 15, which comprises two stents, with the valve extending half way
`down the upper stent, is expressly said by paragraph [0023] to be not part of the
`invention:
`
`
`
`
`
`56.
`Likewise figure 19, described in paragraph [0037], is not part of the invention. In this
`case the valve (41) begins in the second stent (6) and extends into the third stent (61):
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`
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`Edwards Lifesciences Corporation, et al. Exhibit 1038, p. 14 of 43
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`

`

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`
`57.
`
`58.
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`
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`There is one other element of the description to which I should refer. The Patent
`explains in paragraphs [0029] to [0031] that the outside of the stent may be wholly or
`partly covered by a sheath. So, for example, excess valve material may be folded over
`to increase the structural integrity of the device and to present a smoother surface to
`the body upon implantation. Alternatively the sheath may be made of a synthetic
`material such as Dacron.
`
`Before turning to the claims, I think it is of some note that the Patent contains no
`experimental results and no detailed discussion of how the invention may be
`implemented. It assumes, for example, the skilled person can work out the necessary
`structural characteristics of the stent, such as its length and diameter (both crimped
`and expanded) and the dimensions and configuration of its struts and the thickness,
`strength and resilience of the wire from which it is to be made.
`
`The claims - interpretation
`
`59.
`
`The parties sensibly agreed a breakdown of the integers of claim 1:
`
`[A]
`
`[B]
`
`[C]
`
`[D]
`
`[E]
`
`[F]
`
`A stent valve, suitable for placement in a vessel, the
`vessel further having a diameter (84) and an inner
`lumenal surface, comprising:
`
`a) a radially expandable stent (20) having a proximal
`stent end (31) and a distal stent end (33),
`
`the stent having an expanded diameter (86) sized to
`permit contact with an inner lumenal surface of the
`vessel;
`
`b) a valve (41) having a proximal valve end (48) and a
`distal valve end (50),
`
`the valve being at least partially located within an
`inner portion of the stent,
`
`is formed with a collagen
`the valve
`wherein
`containing bio material (38),
`
`characterised in that
`
`[G]
`
`[H]
`
`[I]
`
`[J]
`
`said collagen containing bio material comprises
`pericardium
`
`and extends within said stent (20) substantially from
`said proximal stent end