Neutral Citation Number: [20171 EWHC 405 (Pat)
`
`IN THE HIGH COURT OF JUSTICE
`CHANCERY DIVISION
`PATENTS COURT
`
`Caseiio_:HC-2015-004574
`
`Royal Courts of Justice, Rolls Building
`Fetter Lane, London, EC4A 1NL
`
`Date: 03/03/2017
`
`Before :
`
`HIS HONOUR JUDGE HACON
`(SITTING AS A HIGH COURT JUDGE)
`
`Between :
`
`EDWARDS LIFESCIENCES LLC
`-and -
`BOSTON SCIENTIFIC SCIMED, INC.
`-and -
`
`Claimant
`
`Defendant
`
`(1) EDWARDS LIFESCIENCES CORPORATION
`(2) EDWARDS LIFESCIENCES AG
`(also known as EDWARDS LIFESCIENCES SA)
`(3) EDWARDS LIFESCIENCES LIMITED
`
`Third Party
`Fourth Party
`
`Seventh Party
`
`Piers Acland QC and Miles Copeland (instmcted by Powell Gilbert LLP) for the Claimant
`and the Third, Fourth and Seventh Parties
`Richard Meade QC and Kathryn Pickard (instructed by Olswang LLP) for the Defendant
`
`Hearing dates: 18-20, 23-24 and 26-27 January 2017
`
`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.
`
`HIS HONOUR JUDGE HACON
`
`Edwards Lifesciences Corporation, et al. Exhibit 1036, p. 1 of 53
`
`

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`HIS HONOUR JUDGE HACON
`Anproved Judgment
`
`Judge Hacon :
`
`Introduction
`
`Edwards Lifesciences v Boston Scientific
`
`1. The defendant ("Boston") is the proprietor of two European patents, both of
`which claim inventions entitled "Repositionable heart valve". A valve of the
`type in issue is introduced percutaneously, i.e. using a needle-puncture of the
`skin to introduce a catheter into a blood vessel, via which the valve is pushed
`into position. This is to be contrasted with procedures involving the installation
`of valves by open heart surgery. The valves in the present case were often
`referred to as 'transcatheter heart valves' or THVs.
`
`2. The claimant sought revocation of Boston's EP (UK) 2 749 254 ("254") and EP
`(UK) 2 926 766 ("766") patents ("the Patents"). They are both divisional
`patents derived from the same parent application. The relevant priority date for
`both was 23 December 2003. The description in the specification of each of the
`Patents is largely the same.
`
`3. Boston counterclaimed for infringement and brought additional claims against
`five other companies in the same group as the claimant. The Fifth Party was in
`fact the same as the Fourth Party (being Swiss, it alternatively uses German or
`French designations) and the claim against the Sixth Party was later dropped.
`That left the claimant and three remaining companies as defendants in the
`additional claim, all of them part of the same group. I need not distinguish them
`and will refer to them individually and collectively as 'Edwards'.
`
`4. Despite this being formally a claim for revocation with a counterclaim for
`infringement, the trial went forward in the usual way, as if Boston were the
`claimant in an infringement action against Edwards. The product alleged to
`infringe is Edwards' Sapien 3 THV.
`
`5. Edwards argued that both the 254 and 766 Patents lacked novelty and inventive
`step, relying on four items of prior art. A squeeze was run against both Patents,
`alleging in each case that if the invention claimed was not obvious, necessarily it
`was not sufficiently disclosed in the specification. Finally, there was an
`allegation of added matter in relation to both.
`
`6. In argument attention was paid only to claim 1 of each Patent, save for a brief
`reference to other claims in the context of infringement of 254. Subject to that, I
`need therefore consider only the first claims of the Patents.
`
`7. Richard Meade QC and Kathryn Pickard appeared for Boston, Piers Acland QC
`and Miles Copeland for Edwards.
`
`The technical background to the inventions
`
`8. The parties provided me with a helpful primer, largely plagiarised from the
`judgments of Kitchin J in Edwards Lifesciences AG v Cook Biotech
`Incorporated [2009] EWHC 1304 (Pat) and of Mr Peter Prescott QC in
`Corevalve Inc v Edwards Lifesciences AG [2009] EWHC 6 (Pat). It was
`
`Edwards Lifesciences Corporation, et al. Exhibit 1036, p. 2 of 53
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`

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`HIS HONOUR JUDGE HACON
`Aooroved Judgment
`
`Edwards Lifesciences v Boston Scientific
`
`common ground that everything in the primer formed part of the skilled person's
`common general knowledge as does, therefore, the following shortened form.
`
`The Aortic Valve
`
`9. 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 two circulations are each maintained by the rhythmic
`contractions of the heart, in the case of the pulmonary circulation by the right
`ventricle and in the case of the systemic circulation by the left ventricle.
`
`10. The end of the pulmonary circulation is marked by oxygenated blood returning
`from the lungs to the heart via the pulmonary vein, entering the left atrium.
`From there it passes to the left ventricle, ready to be pumped around the rest of
`the body - the systemic circulation. Between the left atrium and the left
`ventricle there is a valve: the mitral valve. When the left ventricle contracts, the
`mitral valve closes preventing the blood from flowing back into the left atrium.
`Instead the blood flows under high pressure into the main artery of the systemic
`circulation, the aorta.
`
`11. The phase in which the ventricle contracts is known as 'systole', as opposed to
`the phase in which the wall muscle relaxes and the ventricle expands, which is
`known as 'diastole'.
`
`12. Between the left ventricle and the aorta is the aortic valve. As diastole begins
`pressure inside the ventricle rapidly drops, falling below that of the blood in the
`aorta. The difference in pressure causes the aortic valve to close so that the
`blood does not return to the left ventricle during its expansion in preparation for
`a further contraction.
`
`13. The following is a diagrammatic representation of the location of the aortic
`valve between the left ventricle and the aorta.
`
`Ascending Aorta
`
`Aorticsinuseswith
`coronary ostla
`
`Aortic valve
`Aortic valve annulus
`
`Left Ventricle
`
`14. In this diagram the aortic valve is represented by two leaflets. In about 1-2% of
`the population, mostly males, there are indeed two leaflets, but in the rest of the
`population there are three. These leaflets are flaps of tissue which operate as the
`valve. When the left ventricle contracts, the pressure of blood pushes the
`leaHets apart, allowing the blood through. When the contraction ends at the
`start of diastole, the difference in blood pressure across the aortic valve is
`
`Edwards Lifesciences Corporation, et al. Exhibit 1036, p. 3 of 53
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`

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`HIS HONOUR JUDGE HACON
`Approved Judgment
`
`Edwards Lifesciences v Boston Scientific
`
`around 120 mm Hg. The consequent push of blood back towards the ventricle
`causes the leaflets to fall together, blocking the How.
`
`15. It will be seen that the aortic valve sits in the aortic valve annulus, a narrowing
`that marks the division between aorta and ventricle. Also shown in the diagram
`are the coronary ostia, within a few millimetres of the leaflets. These are
`openings within the aortic sinuses. They lead to the coronary arteries which
`supply blood to the muscle of the heart wall and have some significance here
`because it is essential that these are not blocked when a THV is installed.
`
`16. The aorta in the diagram above is marked 'ascending aorta'. It is connected via
`an arch to the descending aorta. These are shown in the diagram below along
`with the coronary arteries and other arteries which branch off the aorta and form
`part of the systemic circulation. A THV intended to replace the aortic valve is
`usually passed up the descending aorta, via the arch, down into the ascending
`aorta and thence to the native valve.
`
`F?t{|hi c.omnion
`o^rotid tirtpry'
`
`Riglrt
`coionaiy
`artery
`
`Heart Valve Disease
`
`17. Heart valve disease may be congenital or it may be acquired. If acquired, it is
`often the aortic or mitral valve that will be affected. The most common
`afflictions are stenosis and regurgitation. In the former condition the leaflets of
`the valve fail to open fully, blocking the passage of the blood into the aorta or
`left ventricle as the case may be. If the patient suffers from regurgitation, the
`leaflets do not fall together to form a tight seal. Consequently some blood leaks
`backwards.
`
`18. These are not mutually exclusive conditions. Both are commonly caused by
`degenerative calcification, which is the accumulation of calcium carbonate in
`the leaflets and the parts of the heart surrounding the valve. The calcium
`carbonate collects to form very hard nodules, stiffening the tissue in which they
`form.
`
`Edwards Lifesciences Corporation, et al. Exhibit 1036, p. 4 of 53
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`

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`HIS HONOUR JUDGE HACON
`Approved Judgment
`
`Edwards Lifesciences v Boston Scientific
`
`Replacing Defective Heart Valves by Surgei-y
`
`19. Surgeons have been replacing defective heart valves in patients for about 40
`years. The only way of doing this until shortly before the priority date was by
`open heart surgery, taking 3-4 hours. The patient's chest is opened, the
`defective valve is cut out and an artificial valve is sewn into place. A general
`anaesthetic is required, as is the use of a heart-lung machine. This is still a
`commonly performed method of replacing heart valves but it is traumatic and is
`not suitable for fragile patients, who are liable to be killed by the procedure.
`
`20. The replacement valves used in open heart surgery take various forms. Some
`are mechanical. These have a long life span but tend to cause thrombus
`formation (blood clots) which require the patient to undergo life-long anti-
`coagulation therapy. Others are biologically derived. The leaflets are either
`homograft (human whole valves), xenograft (animal whole valves) or fabricated
`(tailored from animal pericardium, the tissue that covers the outside of the
`heart). In each case they are mounted within a textile cuff, or in a metallic or
`plastic frame.
`
`Interventional Cardiology
`
`21. In the 1960s a new branch of medicine emerged known as 'interventional
`cardiology', that is to say the practice of treating patients with heart problems
`percutaneously rather than by surgery. It was and remains the province of
`physicians rather than surgeons. Physicians specialising in this field have
`become known as 'interventional cardiologists'.
`
`22. In 1977 the first human balloon angioplasty procedure was performed. A
`catheter carrying a balloon was inserted into an occluded human coronary artery
`and then expanded to force the artery open. In the 1980s other procedures were
`developed, including valvuloplasty: inflating a balloon catheter to open up a
`stenotic heart valve.
`
`Stents
`
`23.
`
`During the 1980s and 90s there was a related development, namely the design of
`expandable stents to treat occluded vessels, in particular coronary arteries.
`These stents have an initial structure of narrow diameter to permit percutaneous
`introduction in a catheter. Then, once in place, they are expanded in diameter to
`form a scaffold inside the artery to hold it open. By the year 2000 stents were
`preferred over balloon angioplasty because they were less likely to result in
`restenosis (re-occlusion).
`
`24. Stents essentially fall into two categories. The first are those which are balloon
`expandable. Once the stent has reached its destination, a balloon inside is
`expanded to force the stent open by plastic deformation. The balloon is then
`deflated and the catheter withdrawn. The second category is self-expanding
`stents. These are made of a spring or 'memory metal', typically nitinol. They
`require a sheath to maintain the stent in its compressed form of narrow diameter.
`Once the stent is in place the sheath is withdrawn and the stent expands.
`
`Edwards Lifesciences Corporation, et al. Exhibit 1036, p. 5 of 53
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`HIS HONOUR JUDGE HACON
`Approved Judgment
`
`Edwards Lifesciences v Boston Scientific
`
`25. Depending on the artery and condition to be treated, stents of differing
`diameters and lengths are required, and they are accordingly made in different
`sizes. By 2000 it was the general practice to size the stent to a diameter
`approximately 10-20% greater than the diameter of the vessel to be treated so as
`to ensure that it would exert radial pressure on the walls of the vessel and
`remain in place. It would also leave the lumen (the cavity of the vessel)
`unobstructed. Self-evidently, the narrower the diameter of the stent in
`compressed form, the greater is the range of vessels in which it can be
`introduced.
`
`Transcatheter Heart Valves
`
`26.
`
`27.
`
`In the late 1980s THVs were developed, so avoiding the need for surgery,
`although at this time they were installed only in animals. In 1989 Dr Henning
`Andersen and his colleagues at Aarhus University in Jutland made a THV
`having an expandable metal frame, within which was a biological valve. This
`was implanted in pigs.
`
`In April 2002 Dr Alain Cribier and his team in Rouen performed the first
`implantation into a human being of a THV. It was installed in place of a native
`aortic valve. Dr Cribier's THV consisted of three bovine pericardial leaHets
`mounted within a balloon-expandable metal frame. By the priority date in
`December 2003 Dr Cribier had acquired celebrity status in his field for this
`breakthrough. Below are two images of Dr Cribier's valve, taken from a paper
`published in October 2003:
`
`Transcatheter Access Routes
`
`28. Most interventional cardiology is performed using a needle inserted into the
`femoral artery (in the groin), although the radial artery (in the forearm) is
`sometimes used. The catheter is passed in a direction against the arterial flow of
`blood, thus known as the retrograde approach, towards the heart.
`
`29. There are other means, introducing the catheter by a needle into alternative
`arteries, including the aorta itself.
`
`30. Access to the heart can also be achieved using the antegrade approach, moving
`the catheter in the same direction as the blood How. In this case the catheter is
`introduced into a peripheral vein, reaching the right side of the heart via the vena
`cava. If access to the left side is required, the catheter must be fed through the
`
`Edwards Lifesciences Corporation, et al. Exhibit 1036, p. 6 of 53
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`

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`HIS HONOUR JUDGE HACON
`Approved Judgment
`
`Edwards Lifesciences v Boston Scientific
`
`wall (known as the septum) between the right and left atria of the heart. This
`technique is used in particular to perform mitral valvuloplasty.
`
`31. The technique of replacing an aortic heart valve percutaneously has become
`known as 'transcatheter aortic valve implantation' or TAVI. It has made a
`dramatic improvement to the lives of many patients.
`
`Terminology
`
`32. Strictly, the valve consists of the leaflets and is distinct from the frame. In many
`of the documents I was shown, the term 'valve' was used more loosely to mean
`the entire device. I will often do likewise. The exception is where I discuss the
`Patents because one of the arguments on the construction of the 254 Patent
`required the distinction to be maintained.
`
`The inventions in summary
`
`33. The claimed inventions can best be described by reference to Dr Cribier's prior
`art device, shown above. (The precise form taken by the frame and leaflets of
`Dr Cribier's device are only illustrative in the context of summarising the
`inventions.) In both inventions a fabric skirt is provided on the outer lower part
`of the frame, thus encircling it. The device sits in the aortic valve annulus,
`pushing aside the diseased leaflets. The fabric skirt lies between the frame and
`the annulus or the frame and the native leaflets. It provides a seal, blocking the
`passage of blood that might otherwise pass around the outside the valve,
`between the frame and the annulus (or native leaflets). In other words, it
`prevents or limits what is known as paravalvular leakage, or PVL.
`
`34. The form taken by the fabric skirt is described in two ways in the specifications.
`The first form is claimed in 254: the seal is 'bunched up' in the deployed
`configuration. The second is claimed in 766: the seal takes the form of 'at least
`one sac'. Boston's case was that the seal could take either or both forms,
`whereas Edwards argued that they are mutually exclusive, a dispute I will come
`back to.
`
`The Person Skilled in the Art
`
`35. It was common ground that the skilled team comprised a clinician and a bio-
`medical engineer. Boston submitted that the clinician was either an
`interventional cardiologist or alternatively a cardiac surgeon, in the latter case
`provided that he or she had sufficient interest in TAVI. Edwards argued that the
`team would never include a cardiac surgeon; the clinician would necessarily be
`an interventional cardiologist.
`
`36. This potentially mattered because a cardiac surgeon would bring with him or her
`(hereafter the possibility of either is to be inferred) common general knowledge
`that would otherwise be absent.
`
`37. The classic characterisation of the person skilled in the art was provided by Lord
`Diplock in Catnic Components Ltd v Hill & Smith Ltd [1982] R.P.C. 183. He
`identified the addressees of a patent specification thus (at p.242):
`
`Edwards Lifesciences Corporation, et al. Exhibit 1036, p. 7 of 53
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`HIS HONOUR JUDGE HACON
`Approved Judgment
`
`Edwards Lifesciences v Boston Scientific
`
`"those likely to have a practical interest in the subject matter of [the]
`invention (i.e. 'skilled in the art')"
`
`Lord Diplock went on to add to this description (at p.243):
`
`"persons with practical knowledge and experience of the kind of work in
`which the invention was intended to be used"
`
`38. So however well read-up an individual may be in a particular art, he will not
`qualify as a skilled person unless he has practical knowledge and experience in
`the relevant field. Practical knowledge and experience will bring in train
`common general knowledge that the 'library' expert in the field will not possess.
`
`39. To include a cardiac surgeon in the skilled team, I had to be satisfied that at the
`priority date such individuals possessed practical knowledge and experience in
`TAVI. Professor Georg Lutter was Boston's expert clinician. He said that in
`late 2003 it was extremely unusual for a heart surgeon even to be interested in
`TAVI. Most had significant reservations for several apparently good reasons
`and in particular because TAVI did not involve removal of the diseased valve,
`as would be done in a surgical replacement. Professor Lutter was one of the rare
`exceptions in that he was interested in TAVI but he had no practical experience
`and even he, at the time, seemed to be primarily interested in a TAVI procedure
`that could include ablation (i.e. excision) of the diseased valve at least in part.
`Only a small number of groups were working on TAVI devices in late 2003.
`Professor Lutter did not suggest that any of them included a cardiac surgeon.
`
`40. This does not necessarily exclude the cardiac surgeon from playing a part in the
`knowledge to be ascribed to the skilled team. In Pfizer Ltd's Patent [2001]
`F.S.R. 16, Laddie J accepted (at [67]) that if an item of prior art flags a
`technology in which the skilled team are inadequately skilled, they would
`consider getting help from someone else. This raises the question whether the
`interventional cardiologist and the bio-medical engineer in the present case,
`exploring a very new field, should be assumed to have taken advice from a
`cardiac surgeon with practical experience in replacing heart valves. On the
`evidence before me, if the skilled team had consulted a cardiac surgeon in
`December 2003 and were lucky enough to find one with a positive attitude
`towards TAVI, they would have been advised to use a procedure in which the
`diseased leaflets were at least partially ablated. With hindsight it can be seen
`that the contribution from the notional cardiac surgeon would have been
`negative.
`
`41. In my view the skilled team consisted solely of an interventional cardiologist
`and a bio-medical engineer.
`
`The Witnesses
`
`42. I have already mentioned Boston's clinical expert witness, Professor Georg
`Lutter. He is Professor of Cardiac Surgery at the University of Kiel and Head of
`the Department of Experimental Cardiac Surgery and the Heart Valve
`Replacement Department. Despite being a surgeon, Professor Lutter has carried
`out many TAVI procedures at Kiel. For most of these procedures Professor
`
`Edwards Lifesciences Corporation, et al. Exhibit 1036, p. 8 of 53
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`HIS HONOUR JUDGE HACON
`Aooroved Judgment
`
`Edwards Lifesciences v Boston Scientific
`
`Lutter used Edwards' Sapien 3 device, having implanted about 250 of these by
`the time of giving evidence.
`
`43. My impression was that Professor Lutter was generally a good witness despite
`occasionally displaying what seemed to me to be a rather drawn out reluctance
`to accept matters of practice known at the priority date, matters made evident by
`contemporaneous documents.
`
`44. Boston's other expert was Professor James Moore. He is currently Professor of
`Biomedical engineering at Imperial College London. Professor Moore's
`particular expertise is in the field of stents.
`
`45. Professor Moore has given expert testimony in nine patent infringement cases in
`the United States, in five of which he was an expert on behalf of Boston. I
`mention this because, I regret to say, in the course of listening to Professor
`Moore I formed the impression that he has also developed what he might regard
`as an expertise in giving evidence. Professor Moore was extremely careful in
`giving his answers. I increasingly took the view that this was because his first
`priority was to avoid saying anything that might damage Boston's case.
`Assisting the court with his honest views was only a secondary motivation, at
`best. This was not helpful. I do not suggest that Professor Moore was going out
`of his way to mislead the court. But if a witness prevaricates at length over any
`answer that might not help the position of his side, the court is unlikely to
`accord much weight to his evidence as a whole. There will always be a strong
`suspicion of persistent bias.
`
`46. This must be put into perspective. Rarely, if ever, is an expert witness wholly
`objective by the time of the trial. Such is the effect of being part of a litigation
`team for which the focussed goal is, understandably, winning the argument.
`And, after all, there is a selection process. Nevertheless many experts find it
`possible to make appropriate concessions where their honest views require
`agreement with a point being put by counsel. No expert may be entirely
`objective but many are willing at least to give priority to assisting the court with
`accurate and helpful technical evidence.
`
`47. This takes me to Edwards' experts. Their expert clinician was Dr Nigel Buller.
`Dr Buller is a retired consultant cardiologist. Until 2008 he was Head of
`Interventional Cardiology at the Queen Elizabeth Hospital, Birmingham and the
`lead clinician for its cardiac catheterisation laboratories. During the course of
`his career Dr Buller developed an interest in interventional cardiology and had
`hands-on experience with the insertion of coronary stents. TAVI procedures
`were not used in the UK until 2008, a while after the priority date, by which
`time Dr Duller had stopped performing invasive procedures. He later received
`some training in TAVI at the New York Presbyterian Hospital in 2013.
`
`48. Dr Duller, like Professor Moore, has experience of being an expert witness in
`several proceedings, both in this country and in the United States. There the
`comparison ends. I found Dr Duller to be an excellent witness. He gave clear
`and direct answers without undue delay whenever he was able to. My
`impression was that Dr Buller was occasionally susceptible to hindsight and
`
`Edwards Lifesciences Corporation, et al. Exhibit 1036, p. 9 of 53
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`HIS HONOUR JUDGE HACON
`Approved Judgment
`
`Edwards Lifesciences v Boston Scientific
`
`liable to accord more creativity to the skilled person than was appropriate in
`law. This, though, is not a criticism, just an observation.
`
`49. Edwards' expert on biomechanical engineering was Professor John Fisher. He
`has been Professor of Mechanical Engineering at the University of Leeds since
`1993 and is current Pro-Vice-Chancellor for Research at that university. He is
`also a director of four externally funded centres of research into medical
`engineering.
`
`50. Professor Fisher did not claim any in-depth knowledge of TAVI procedures
`although he had read some of the commercial and academic literature in that
`field. He was a good witness so far as his evidence went.
`
`Common General Knowledge
`
`The law
`
`51. There was no dispute about the law. The general principles are well established
`and this was not a case which turned on a particular aspect of the law regarding
`what falls within or outside the common general knowledge. Recently Kitchin
`LJ provided the following summary in Idenix Pharmaceiiticals Inc v Gilead
`Sciences Inc [2016] EWCA Civ 1089:
`
`"[72] It follows that the common general knowledge is all that
`knowledge which is generally regarded as a good basis for further action
`by the bulk of those who are engaged in a particular field. It is that
`knowledge which those working in that field will bring to bear when they
`are reading or learn of a piece of prior art. It is not necessary that those
`persons have that knowledge in their minds, however. The common
`general knowledge includes material that they know exists and which
`they would refer to as a matter of course if they cannot remember it and
`which they understand is generally regarded as sufficiently reliable to use
`as a foundation for further work."
`
`This case
`
`52. The parties were agreed that the contents of the primer formed part of the
`common general knowledge including, in particular, the celebrated work done
`by Dr Cribier not long before the priority date. The first implantation of a THV
`into a patient's aorta was done by his team in April 2002. The patient was a
`man aged 57 who died 17 weeks later, although for reasons unrelated to the
`valve implantation. The work was presented in a paper delivered by Dr Cribier
`to a conference in Washington in September 2002 and was also published as a
`special report in the journal Circulation in December 2002 ("the 2002 Cribier
`paper"),
`
`53. Dr Cribier was also one of the authors of a review paper published in 2003 in
`the British Journal of Cardiology ("Dalby"). Dalby reported that a further three
`patients had been treated using TAVI. The second died because the THV could
`not be properly implanted and was ejected into the aorta. In the third and fourth
`cases the implantation was successful.
`
`Edwards Lifesciences Corporation, et al. Exhibit 1036, p. 10 of 53
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`HIS HONOUR JUDGE HACON
`Approved Judgment
`
`Edwards Lifesciences v Boston Scientific
`
`54.
`
`Professor Lutter referred to a review paper of which he was the leading author,
`published in Annals of Thoracic Surgeiy in December 2004, reviewing literature
`no later than May 2004. Professor Lutter said that given the delay of scientific
`publications, this provided a reasonably contemporaneous record of the state of
`TAVI in December 2003. This was not challenged. The paper included the
`following (omitting footnotes):
`
`"A number of technical difficulties were encountered in the early phases of
`percutaneous valve replacement, which to varying degrees still exists.
`These difficulties include optimal attachment of the valve into the stent,
`preservation of the function of the valve stent after compression and re-
`expansion, a suitable visualization method, functional anchoring
`mechanism, and avoidance of paravalvular regurgitation and obstruction of
`coronary orifices in aortic implantation."
`
`55.
`
`Thus, avoiding or at least minimising PVL was one of the concerns of those
`interested in TAVI. Boston identified three areas of dispute with regard to the
`common general knowledge of the skilled person in December 2003, although
`this expanded during argument:
`
`(i) The extent to which PVL was known to be a problem in TAVI
`procedures and the precise nature of likely PVL.
`
`(ii) The extent to which surgical replacement valves were known, i.e. the
`type of valves sewn into patients during open-heart surgery.
`
`(iii)
`
`The extent to which stents or endografts were known.
`
`56.
`
`An endograft is a stent with an external fabric covering. It is introduced into an
`artery and deployed at the site of an aneurysm, then expanded. Blood flows
`through the channel within the endograft thereby relieving the pressure on the
`aneurysm in the artery wall.
`
`Knowledge of the types of PVL
`
`57. For the purpose of his evidence at trial, Professor Lutter divided leakage in the
`context of an aortic valve into three types. Type 1 leakage occurs when blood
`passes through defective leaflets, i.e. through the valve itself. This is the
`leakage which results in regurgitation in diseased native valves but can also
`occur in defective replacement valves.
`
`58. Leakage of Types 2 and 3 occur only with replacement valves. Type 2 happens
`when the valve is not accurately placed in the annulus, so that the leaflet in the
`replacement valve does not meet the frame at the point where the frame is in
`contact with the annulus. Type 3 leakage could happen whether the valve was
`accurately positioned or not. It is leakage between the annulus and the frame.
`The distinction is best demonstrated using Professor Lutter's diagrams: below
`are two forms of Type 2 leakage and then Type 3:
`
`Edwards Lifesciences Corporation, et al. Exhibit 1036, p. 11 of 53
`
`

`

`HIS HONOUR JUDGE HACON
`Aooroved Judgment
`
`Edwards Lifesciences v Boston Scientific
`
`I
`
`\
`
`! I
`
`Type 2 leakage
`
`Type 3 leakage
`
`59. In his report Professor Lutter suggested that Type 3 leakage was little known or
`understood in late 2003 and that to the extent that it was acknowledged, the
`skilled person would have expected to solve it by ablating the native leaflets. In
`the TAVI procedure, the native leaflets, generally studded with calcium nodules,
`are left in place, squashed against the annulus. In December 2003 there was no
`practised method of ablating the leaflets.
`
`60. I think the picture presented by Professor Lutter was contradicted by papers
`published at around the priority date. These included a paper about the new
`TAVI procedure published in April 2002 in The Journal of Thoracic and
`Cardiovascular Surgery, with Professor Lutter as lead author ("the 2002 Lutter
`paper"). At this time Professor Lutter and his colleagues practised TAVI in
`pigs. At the end of the article there are comments from Dr Alain Carpentier, a
`renowned cardiac surgeon:
`
`"We also know from clinical practice, that if you leave even a small
`peripheral leak, it has some very often important deleterious effect, even
`a rather small leak, either haemolysis or insufficiency. Knowing that you
`will never be able to remove all the calcium formation, then you have a
`high risk of having peripheral leak. How can you solve that problem?"
`
`Edwards Lifesciences Corporation, et al. Exhibit 1036, p. 12 of 53
`
`

`

`HIS HONOUR JUDGE HACON
`Approved Judgment
`
`Edwards Lifesciences v Boston Scientific
`
`61. While it is not certain what Dr Carpentier had in mind, 'peripheral' leakage
`sounds very much like Type 3. Dr Carpentier's view, a year and a half before
`the priority date, was that the presence of calcium nodules in the native leaflets
`and artery w^ll and the difficulty of removing them created a high risk of
`'peripheral' leakage, a problem to which there was no obvious solution.
`
`62. Dr Buller was cross-examined on this topic. He said that he could not disagree
`more with Professor Lutter: that at the priority date those in the field did not
`distinguish between Professor Lutter's Type 2 and Type 3 leakage. PVL was
`known and just thought of as blood flowing round the outside of the valve, as
`opposed to through the valve. I accept that evidence. There was no sign that
`anyone had considered Type 2 leakage in advance of Professor Lutter's report
`for this trial. Even Professor Lutter in cross-examination conceded that in 2003
`no distinction was drawn between Type 2 and Type 3 leakage in relation to the
`mild regurgitation reported following Dr Cribier's TAVI procedures.
`
`63. In my view the skilled person at the priority date would have contemplated
`leakage and would have mainly considered the possibility of blood leaking
`around the outside of any implanted valve. Hereafter my references to 'PVL'
`are to be given that meaning, i.e. Professor Lutter's Type 3.
`
`64. A separate although related argument was advanced by Boston, particularly in
`closing: at the priority date PVL was not considered to be a big problem.
`Paravalvular regurgitation was described as 'moderate' in the 2002 Cribier
`paper and Dalby referred to Dr Cribier's work as having resu