Cook Incorporated v Endo Vascular Technologies Inc

[2000] APO 13

OFFICIAL NOTICE

DECISION OF A DELEGATE OF THE COMMISSIONER OF PATENTS

Application:  No. 669338 in the name of Cook Incorporated

Title:  Expandable Transluminal Graft Prosthesis for Repair of Aneurysm and Method for Implanting

Actions:  S.59 opposition by Endo Vascular Technologies Inc.

and Application under R.5.10(4) by the opponent to serve further evidence.  Hearings on both matters.

Decision:  Issued

Abstract:  Opposition successful.

Claims not clear, characterising features of the invention not fully described, working-inter-relationship of characterising features not fully described, and invention in its broadest form not fully described.

Five claims not novel and/or lack an inventive step.

One feature in claim 1 treated as prima facie inessential for purpose of determination of novelty and inventive step.

Multiple embodiments, but no objection that there was no best method of performance because there was no indication of a preferred embodiment.

Application to serve further evidence refused. The evidence would not contribute to a more correct, just, or expeditious result.

PATENTS ACT 1990

DECISION OF A DELEGATE OF THE COMMISSIONER OF PATENTS

Re:Patent Application No. 669338 by Cook Incorporated and opposition under S.59 by Endo Vascular Technologies Inc.

BACKGROUND

Patent application 27353/92 in the name of Cook Incorporated (Cook) was filed on 28 October 1992.  The application is a Convention application, based on three earlier US applications, the earliest of which was filed on 25 October 1991. The other two priority dates are 15 April 1992 and 21 October 1992.  The present Australian application was advertised accepted on 6 June 1996 as No. 669338.  Endo Vascular Technologies Inc. (Endo Vascular) filed a notice of opposition to the grant of the patent on 5 September 1996 followed by service of Statement of Grounds and Particulars on 5 December 1996. Service of evidence-in-support of the opposition was completed on 12 September 1997, service of evidence-in-answer was completed on 11 March 1998 and service of evidence-in-reply was completed on 12 March 1999, following a decision of the Commissioner, dated 24 February 1999, to grant an extension of time to serve the evidence-in-reply.

The opposition was heard in Melbourne on 2 August 1999. The applicant was represented by Dr John Emmerson QC and Mr Alun Thomas, patent attorney. The opponent was represented by Mr Geoff Pryor, patent attorney. Mr Richard Godlewski was in attendance for the Applicant.

On 10 August 1999 the opponent applied for leave to serve further evidence, under Reg. 5.10(4). The opponent objected to the further evidence, and that matter was heard in Melbourne on
18 October 1999. The applicant was represented by Mr Thomas and the opponent was represented by Mr Pryor. Messrs Godlewski and Agnew were in attendance for the Applicant.

THE SPECIFICATION

The specification indicates that the invention relates to positioning a tubular-shaped prosthesis within a lumen such as the abdominal aorta, to strengthen areas prone to aneurysmal dilation. The prosthesis comprises a tubular graft provided with spring assemblies and anchoring barbs. The prosthesis is mounted inside an introducer sheath and the sheath is inserted into a body lumen. As the sheath is being removed the prosthesis is exposed, maintaining its axial position, and the spring assemblies expand and anchor the graft to the internal wall of the lumen.

Some important features referred to in the description and abstract in the specification are:

• An apertured tubular carrier inside the sheath; the prosthesis assembly is mounted on the end of the tubular carrier.

• Mooring loops (sutures) which pass through the apertures in the tubular carrier, and are attached to the prosthesis assembly at one end and which engage a central control means at the other end.

• A central control means which passes through the bore of the tubular carrier, and which comprises a catheter or control wires or threads, which is/are withdrawn to release the mooring loops.

The invention is defined by 12 claims which read as follows:

"1.   A delivery arrangement for translumenally positioning a prosthesis assembly of predetermined shape and size at a particular position on an internal wall of a lumen, said assembly comprising a graft and a spring arrangement for engaging the internal wall of a lumen with the said graft, said delivery arrangement comprising an outer sheath for surrounding the said assembly when the latter is located at the said particular position, and means for retaining the said assembly at the particular position whilst the outer sheath is being removed, characterised in that the retaining means is temporarily positioned near the proximal end of the said assembly and has connected thereto an attachment arrangement to be temporarily attached to the said assembly at one or more positions remote from the proximal end of the said assembly.

2.  A delivery arrangement according to claim 1, characterised in that the retaining means comprises an elongated member to be extended within the assembly, and in that the attachment arrangement is extended between the said elongated member and the said assembly at the said one or more positions.

3.  A delivery arrangement according to claim 2, characterised in that the elongated member is tubular and has a dilator head at the distal end thereof, said head serving to facilitate penetration of the arrangement within the lumen, and to minimize deleterious blood flow through the lumen during positioning of the assembly.

4.  A delivery arrangement according to claim 3, characterised in that a contraction arrangement is provided to temporarily pull the said assembly inwardly to a compressed condition whilst the assembly is within the sheath, and in that a disabling arrangement is provided for expandably releasing the said assembly either during or after removal from the sheath.

5. A delivery arrangement according to claim 4, characterised in that the contraction and disabling arrangements form part of the attachment arrangement, and in that part of the contraction and disabling arrangements are located and controlled from within the elongated tubular member.

6.   A delivery arrangement according to claim 5, characterised in that the attachment arrangement comprises one or more connectors each in the from of sutures connected at one end to the said assembly and at the other end to inside of the elongated tube via apertures and in that the disabling arrangement is provided for releasing the sutures from inside the elongated tube.

7.   A delivery arrangement according to any one of the preceding claims, in which the lumen for receiving the graft is bifurcated, characterised in that the graft has a common section and two bifurcated sections shaped and sized to conform to the respective parts of the bifurcated lumen, in that the said spring arrangement is associated with the common section of the graft and one bifurcated section, and in that another spring arrangement is designed to be translumenally positioned within the said other bifurcated section.

8.   A delivery arrangement according to claim 7, characterised in that one or more identification markers are provided on at least the said other bifurcated graft section.

9.    A delivery arrangement according to claim 7 or 8, characterised in that the said other bifurcated graft section is provided with an arrangement whereby the said other section can be translumenally drawn into position within the respective lumen part.

10.  A delivery arrangement according to any one of the preceding claims, characterised in that the or each spring or graft assembly comprises at least barbs at the distal end of the assembly.

11.   A delivery arrangement according to any one of claims 1 to 6, characterised in that one end of the graft is sealed to prevent flow of blood through the lumen.

12.   A delivery arrangement for translumenally positioning a prosthesis assembly at a particular position on an internal wall of a lumen, the delivery arrangement being substantially as hereinbefore described with reference to the accompanying drawings."

GROUNDS OF OPPOSITION

The Statement of Grounds and Particulars alleges that the invention is prior published, not a manner of manufacture, not novel and does not involve an inventive step, and the specification does not comply with S.40 of the Act.

THE EVIDENCE

The opponent’s evidence-in-support is summarized as follows:

Declarations dated 30 May 1997 and 24 July 1997 by Geoffrey Charles Pryor and exhibits GCP1 to GCP23. The exhibits are prior patents in the field of the present invention; Mr Pryor attests to publication dates and other formality matters relating to some of these patents.

A declaration dated 9 September 1997 by Michael Joseph Denton and exhibits MJD1 to MJD3.

Dr Denton declares that he is a vascular surgeon with extensive practical experience. He explains that the background of the present invention relates to the practice of endovascular surgery, which involves making a small incision in one part of an artery or vein and guiding a device to the site where the repair procedure is to be carried out. He indicates that he is aware of the prior use of graft assemblies with attachment hooks. He also declares that:

• Endovascular surgery is a comparatively new field of surgery which only has a few practitioners in Australia.

• The description of the present invention is incomplete and it is not possible to clearly understand how some aspects of the present invention work; the positions where the mooring loops (sutures) are connected to the graft for example.

• The present claims are not clear; eg:
      The significance of the retaining means positioned “near the proximal end of the assembly” is not clear, because the tubular carrier 21, which embodies the retaining means, is described and shown as being temporarily throughout the graft assembly and is withdrawn therefrom after deployment, (parag.23).

  It is not clear why the proximal end of the assembly should be excluded from where the attachment arrangement is temporarily attached (parag.24).
      The claim does not provide any definition of the purpose for having the attachment arrangement (parag.25).

• The claims cannot be distinguished from the disclosures in published patent specifications such as AU 78,092/91 (Parodi), US 4,950,227 and other patent specifications.

The applicant’s evidence-in-answer is summarized as follows:

A declaration dated 9 March 1998 by David Ernest Hartley, with Exhibit DEH-1.

Mr Hartley is a radiographer with the Royal Perth Hospital; he has recently been involved with activities in the hospital’s endovascular surgery unit, including the choosing of prostheses for patients. Referring to Dr Denton’s declaration, he declares that:

• The description of the invention is easily understood.

• The retaining loops and control wires described “are required in order to maintain tension on the proximal end of the device and to pull it out of the sheath as the sheath is withdrawn and to provide release of the device when final deployment is required.” (parag.12)

• The invention described is specifically designed for the self-expanding stent/graft described in the specification, and is not suitable for positioning different types of prostheses such as stents alone or balloon expandable devices (parags.14, 15).

• The prosthesis is temporarily positioned near the proximal end of the assembly so that it can be stretched taut (parag.17).

• The systems described in the cited prior art use a balloon catheters; these would not be capable of deploying a spring expanded prosthesis.

The opponent’s evidence-in-reply is summarized as follows:

A declaration dated 9 March 1999 by James May, with Exhibits JM-1 and JM-2.

Dr May is a vascular surgeon with experience in using endoluminal prostheses, including the device described in the present specification. He agrees with Dr Denton's assessment of the

difficulties in construing the present specification and claims; in particular he declares:

• "There is considerable confusion over the role of the mooring loops".

• He is "familiar with the stretching concept referred to by Mr Hartley … but this is not what is described in the terminology of the claim nor is it disclosed in the specification .."

He also declares that there is some sort of business relationship between Mr Hartley and the applicant or companies associated with the applicant.  In the matter of the prior art he declares that "the delivery system disclosed in Specification No.78092/91 could deliver a self-expanding prosthesis if slight modifications were made."

Declarations dated 25 February 1999 and 11 March 1999 by John Perry Fletcher, with Exhibits JPF-1 and JPF-2.
           Prof Fletcher also is a very experienced vascular surgeon and he generally supports the declaration of Dr Denton. In particular he agrees that the graft delivery system described in Specification No. 78092/91 would be capable of delivering other types of graft assemblies other than those specifically referred to in that specification.

SUBMISSIONS

Both parties made comprehensive oral submissions at the hearing and provided written submissions. I will refer to the submissions where appropriate in the following paragraphs of my decision.

DECISION

S.40 AND CONSTRUCTION ISSUES

I shall first deal with the supposed “characterising” features in the last four lines of claim 1; some considerable analysis is necessary because the claims use different expressions to those used in the description. The feature "the retaining means is temporarily positioned near the proximal end of the said assembly …" is the first characterising feature.

The main construction problem relates to which features described constitute the “retaining means” claimed. The paragraph in the specification from line 30 page 4 to line 7 page 5 refers to a “main retainer assembly”, which includes “an elongated member” and two “attachment assemblies”. There is also reference to an “inner catheter” in the same paragraph, which appears to have the same function as the central control means described elsewhere. The intended functions of these components is clear enough, but it is not clear from this paragraph whether the inner catheter is meant to be a component of the “retainer assembly”.

Pages 17 and 20 of the specification refer to a feature of the invention described as “partial withdrawal”. This involves separately positioning each end of the graft assembly by the use of two sets of mooring loops: the set at the distal end is released first by partially withdrawing the central control shaft to a point between the two sets of mooring loops, then the proximal end of the assembly is positioned by full withdrawal of the central control shaft. The central control shaft could be construed as being “temporarily positioned near the proximal end of the assembly” during this partial withdrawal procedure, and therefore the “central control means” generally described could be construed as being the retaining means in claim 1. Also, the “elongated member” in claim 2 could be construed as the central control means.

However, other facts before me suggest that this construction may not be what is intended, viz:

(i) Claim 3 clearly indicates that the retaining means in claim 1 is meant to include the tubular carrier.

(ii) The applicant’s evidence and submissions suggest that the retaining means is embodied by the tubular carrier.

(iii) Claim 5 suggests that the central control means is inside the tubular carrier.

However, this construction causes confusion because there is no description in the specification of the tubular carrier  being temporarily positioned near the proximal end of the assembly. Dr Denton states in paragraph 23 of his declaration:

"What I understand occurs is that the graft 1 will remain on the tubular carrier 21 whilst the introducer sheath 4 is removed and the central control means 26 operated. After release of the graft, the tubular carrier 21 is removed from the patient's body. I therefore cannot really understand what is intended to be defined in [claim 1] because the retaining means is temporarily positioned throughout the graft assembly and is withdrawn therefrom after deployment. I therefore do not understand the significance of referring to the temporary positioning near the proximal end of the assembly."

Mr Hartley responds to this in paragraph 17 of his declaration:

"My understanding is that the prosthesis is temporarily positioned near the proximal end of the assembly so that it can be stretched taut (for ease of withdrawal of the sheath) by the attachment arrangements that are in positions remote from the proximal end. If the description is taken at its face value it is not difficult to understand."

My understanding of how the invention works is the same as Dr Denton's; the embodiments of the invention clearly show the tubular carrier extending all the way through the prosthesis assembly whilst it is being positioned. Mr Hartley's reference to the prosthesis being temporarily attached near the proximal end of the assembly is confusing, and I assume incorrect since the "assembly" is in fact the prosthesis. Even if Mr Hartley meant to say the tubular carrier  is temporarily positioned near the proximal end of the assembly so the so the assembly can be stretched taut, the feature is still not clear because it is not clear how this is achieved. It would seem to me that, if anything, the assembly would be axially compressed by positioning the tubular carrier at the proximal end, and presumably not at the distal end. It may be that the stretching taut of the assembly is associated with the feature of the "attachment arrangement … at positions remote from the proximal end of the assembly", rather than the feature of the retaining means being positioned near the proximal end of the assembly. In the former, with the distal end of the assembly attached to the carrier, the proximal end would presumably move with the sheath as it is withdrawn, thus stretching the prosthesis assembly.

It is possible that Mr Hartley meant to say the prosthesis is temporarily positioned near the proximal end of the carrier; but this seems unlikely since it would infer that claim 1 is incorrect; and, with such an arrangement it is again difficult to understand how stretching would occur. Also, no such arrangement has been described.

Mr Hartley did not make any comment about whether the "retaining means" in claim 1 could include the central control means, as well as the tubular carrier, and no other part of the applicant’s evidence suggests this construction, despite the above-mentioned references in pages 17 and 20.

Dr Emmerson suggested that this feature of  "the retaining means [being] temporarily positioned near the proximal end of the said assembly …".  is defining a particular result: it is referring to the part of the tubular carrier near the assembly which is temporarily "functioning" near the proximal end.

My comments on this suggestion are: firstly, this construction implies that the claim includes the tubular carrier passing all the way through the assembly, but that the feature of the retaining means being near the proximal end of the assembly is only referring to that part of the tubular carrier. This I think is a strained construction of the claim; in my view a skilled addressee of the specification would construe the claim to mean that the retaining means is temporarily not positioned near the distal end because it is stated as being near the proximal end.

Secondly, it is not clear what "function" is occurring at the proximal end of the tubular carrier. The reference to "whilst the outer sheath is being removed" in claim 1 suggests that the "temporary positioning" is occurring at this time. Given this, it is difficult to see what function the proximal end of the tubular carrier is performing: whilst the sheath is being removed the distal end of the carrier seems to be performing some function since that's where the attachment arrangement is effective, but the proximal end of the carrier seems to have rather minimal involvement.

Another construction of the "characterising" features in claim 1 might be that the temporary positioning of the retaining means and temporary attaching of the attachment arrangement occurs during loading of the assembly into the sheath. However, if this is meant to be the correct construction, the characterising portion of the claim causes confusion when read with the rest of the claim which refers to delivering the prosthesis and removing the sheath.

Dr Emmerson suggested that the opponent has disregarded the functional components and "positioning aspect" of claim 1. In my view this "positioning aspect" in the claim is generally difficult to construe.

On page 17 lines 26-32 of the specification there is a reference to the carrier not traversing the graft to the distal end, and this is specifically with reference to loading the carrier into the sheath (in particular by a "breech-loading" method). However this disclosure is not a proper basis for the said characterising feature in claim 1:  it is not relevant because it is describing an arrangement where the carrier tube is not used to hold the assembly in place on delivery. On lines 30 and 31 it is stated "no attachment to graft 1 would then be needed …".  

The opponent's evidence suggests that this feature of the retaining means being "temporarily positioned near the proximal end of the assembly" is a mystery to its experts. This feature is defined in claim 1 as one which "characterises" the invention; and this suggests that it is important and essential to the working of the invention; which makes it all the more important that it should be clearly defined in the specification. My conclusions on this feature are:

• Firstly, claim 3, and claims 1 and 2 construed in the light of claim 3, do not define the invention described because they include an arrangement where the tubular carrier is temporarily positioned near the proximal end of the assembly, and no such arrangement has been described in the body of the specification. The specification therefore fails to comply with S.40(2)(b).

• Secondly, it is not clear whether the described central control means is meant to be part of the “retaining means” in claim 1 and whether it embodies the “elongated member” in claim 2. The description on pages 17 and 20 suggests that this may be so, but in my view, claim 3 suggests otherwise. The specification generally would confuse an addressee on this issue, and the applicant’s evidence does not support this construction. Thus these claims are not clear and the invention has not been fully described in its broadest form. The specification therefore fails to comply with S.40(3) and S.40(2)(a).

Re the feature "an attachment arrangement to be temporarily attached to the said assembly at one or more positions remote from the proximal end of the assembly." 

Prima facie this feature is somewhat easier to construe than the above-mentioned feature, since it seems compatible with the invention described; the stretching of the assembly upon removal of the sheath seems to be associated with this feature. Nevertheless, the opponent's declarants all indicate that they had difficulty understanding the best locations on the prosthesis assembly for attachment of the mooring loops.

In paragraph 12 of his declaration Mr Hartley, for the applicant, refers to the mooring loops and control wires and threads. He states:

"It is clear to me that these devices are required in order to maintain tension on the proximal end of the device and to pull it out of the sheath as the sheath is withdrawn and to provide release of the device when final deployment is required."

It is not clear to me why Mr Hartley specifically refers here to the proximal end of the "device" (the device presumably being the assembly) since it would seem to be advantageous to maintain tension over the whole length of the assembly as it is removed. His comment could be construed to suggest that somehow mooring loops remote from the proximal end would continue to provide tension throughout the graft assembly as the sheath is being removed, but it still does not explain why it is preferable, presumably since it is a characterising feature of the invention, to attach the mooring loops at positions remote from the proximal end. Dr Emmerson submitted that the positions on the assembly remote from the proximal end are important because there is "a need to hold that position" and not rely on the spring hooks as the sheath is removed.

Page 18 of the specification describes how:

• “the distal (upstream) end of the graft 1 is [my italics] then moored around the central control means 26 with a mooring loop 39 …” (lines 7-9) and

• “ the proximal (downstream) end of the graft 1 can [my italics] also be secured in the same manner through a second set of mooring loops 39’ …” (lines 21-23).

This part of the description suggests that it is optional whether the proximal end is also moored to the central control means, and it does therefore provide some basis for the claim, but I note that it is the only reference in the specification to this feature. None of the specific embodiments shown in the 49 figures of drawings for example show this feature. There is no discussion in the specification on why it is a “characterising” feature of the invention, eg. whether there are any particular advantages over the prior art attributed to not mooring at the proximal end. In fact, one device described in the specification, an “umbrella graft” (fig.19, page 22) does not have an attachment arrangement at all; this graft-spring assembly is simply released by a pusher catheter and withdrawing the surrounding sheath.

The feature of  "an attachment arrangement to be temporarily attached to the said assembly at one or more positions remote from the proximal end of the assembly" is defined in claim 1 as one which "characterises" the invention; this suggests that it is important and essential to the working of the invention. The opponent’s declarants have indicated that the minimal description of this feature in the body of the specification is leads to some confusion. I tend to agree with this concern and therefore conclude that this aspect of the invention is not fully described, and that the specification fails to comply with S.40(2)(a).

Another construction problem arises when the characterising features of claim 1 are put together.  In the “partial release” arrangement previously described, there is an attachment arrangement at each end of the assembly, the distal end is first released, then the proximal end. Consequently, it is not clear how a partial release could be effected if there was only the one attachment arrangement, at the distal end. Presumably, if there was no attachment at the proximal end, the second step in the partial release could not be effected, and release of the arrangement at the distal end would in effect completely release the assembly. Insofar as these features have been described in the specification, the working inter-relationship between the two characterising features in claim 1 is not clear; ie. the arrangement of the retaining means being temporarily positioned near the proximal end of the assembly only seems to have a purpose when the attachment arrangement is at both ends of the assembly. Thus I conclude that claim 1 is not clear. The working inter-relationship of these features has not been described in the specification; thus I conclude that the invention has also not been fully described in its broadest form. The specification therefore fails to comply with S.40(2)(a) and S.40(3).

The opponent also argued that the specification does not describe the best method of performance of the invention, essentially because there are five or so embodiments described and the specification does not provide any basis for determining which of the embodiments is best. Mr Prior referred me to the decision of the Federal Court in Firebelt Pty Ltd v Brambles Australia Ltd (1999) AIPC 91-471.

Mr Thomas submitted that S.40 does not require the specification to indicate which embodiment is "the best" if several are described, "since identification of which method of working the invention is the best may depend on circumstances."

I agree with Mr Thomas's general comments on the law; the requirement of the inventor to describe his "best method of performance" is to protect the public against a patentee "who deliberately keeps to himself something novel and not previously published which he knows of or has found out gives the best results, with a view to getting the benefit of a monopoly without giving to the public the corresponding consideration of the best method of performing his invention" (American Cyanamid Co. v Ethicon Ltd [1979] RPC 215 at 269). An inventor who describes more than one best method is providing more information to the public than he is required to do and therefore should not be fettered in any such endeavour. I am not aware of any precedent which requires a specification to indicate which of several methods described is the best method.

The Firebelt v Brambles case related to a "lid opening device". It was a feature in the claims, and it was clear from the claims that the device was located on the "loading mechanism". However, the description only referred to the lid opening device as being on the "transfer mechanism". The Court decided that the breadth of the claim did not mean that the invention was not fully described, but that the best method of performing the invention as a whole had not been disclosed. The circumstances reported did not include problems caused by there being a multiplicity of embodiments. In my view this case is not a good legal basis for Mr Prior's submission, and I am satisfied that the specification describes the best method of performance of the invention.

MANNER OF MANUFACTURE

Mr Prior submitted that the present invention failed the threshold requirement for an alleged invention, as set out by the High Court in Phillips v Mirabella (1995) 32 IPR 449, when comparing it to some of the prior art described on page 1 of the specification. In particular he referred to US Patent Nos. 4,512,338 (GCP-6) and 4,787,899 (GCP-1).

US Patent No. 4,512,338 relates to an arrangement where a graft is sewn to a shape-memory alloy wire, which upon reaching body temperature on delivery forms a coil shape to bridge a weakened portion of a body lumen. The graft is delivered by removing a sheath and holding the graft by a stiff rod with a platform at the end. Prima facie there seems to be no part of the prior art apparatus which extends inside the graft assembly.

US Patent No. 4,787,899 relates to a grafting system where a balloon catheter is inflated to staple a graft to the internal wall of a body lumen. One end of the graft is fitted in a hollow cylindrical guide (dilator head) which is moved forward on delivery by a push rod within the catheter. The present invention is different because it has a spring arrangement for engaging the graft and has an extended sheath which initially completely surrounds the assembly and which is removed by withdrawing, not pushing forward. Also I agree with the applicant's submission in this matter that the "attachment arrangement" of the invention is something more than  a mere "frictional fit", as suggested by the opponent.

In my view the present invention satisfies the threshold requirement in the light of this prior art in particular, and the other prior art referred to in the evidence, because the invention appears to be an improved arrangement, or at least an alternative arrangement, for controlling the positioning of a spring-type graft assembly during the process of withdrawal of the sheath and delivery of the graft assembly. Such subject-matter is a manner of manufacture.

NOVELTY and INVENTIVE STEP

Re the matter of construction of the claims for the purpose of determining whether they are novel or involve an inventive step: I have found that there are serious S.40 objections to the supposed "characterising" features in claim 1 and to the description supporting the claim, and consequently it is difficult to determine whether these features of claim 1 are essential or inessential. Despite these features being in the "characterising" part of the claim, which would suggest they are essential, the lack of description of (i) the invention in its broadest form, and (ii) the working inter-relationship between these features, suggests that these features may not be essential. The APO Manual of Practice and Procedure, Vol.2 parag. 3.8.8 suggests that under these circumstances in examination "the examiner should assume in the first instance that the feature is inessential."

I think that practice is also generally applicable to the present situation; such a construction would allow me to make a more comprehensive comparison between the claims and the citations, and, if it resulted in further objections to the specification, it would not be determinative of the opposition since I have already decided that there are serious deficiencies under S.40. (Such practice may not be applicable in an opposition if it was determinative of the result of the opposition). I think it is also appropriate that I consider the relative weight of these considerations for each characterising feature of claim 1.

Re the first characterising feature, I think it is appropriate that I construe the feature of the retaining means being temporarily positioned near the proximal end of the assembly as being inessential, because generally it causes more construction problems: I have found this feature to be not clear and not defining the invention. However, the retaining means per se, separately referred to in line 7 of claim 1, is an essential feature.

Re the second characterising feature of the attachment arrangement being temporarily attached to the assembly at one or more positions remote from the proximal end I have not found to be not clear or not defining the invention, therefore I think it is appropriate to consider this second feature as being essential for the purposes of determining novelty and inventive step; ie. the "characterising" aspect of the second feature outweighs the S.40 problems.

Exhibit MJD-4 is a copy of a report in 170 Radiology, published March 1989 (before the earliest priority date of the present claims) entitled Percutaneously Placed Endovascular Grafts for Aortic Aneurysms: Feasibility Study. The report describes the use of self-expanding spring assemblies for expanding a graft; anchoring barbs are also attached at the ends of the graft. In the paragraph under the heading Graft Placement and Follow-up there is described a placement method comprising compressing the graft and advancing it through an introducer catheter with a blunt-tipped introducer wire. The paragraph goes on:

"When the nylon-covered portion of the graft had bridged the aneurysm, the introducer wire was held tight and the catheter was slowly withdrawn, releasing the graft and allowing it to expand."

This technique is recognized in page 1 of the present specification as relevant prior art. Given my above construction of the characterising features in claim 1, in my view claim 1 as a whole is not anticipated by the disclosure in the above-mentioned report. The "retaining means" in the claim is anticipated by the blunt tip of the introducer wire, which retains the graft in position as the catheter sheath is removed; but there is no disclosure in the citation of an attachment arrangement between the graft and the introducer wire (retaining means). Claim 1 is therefore novel in the light of the citation.

Re the matter of inventive step, the report indicated that there were some problems with the method used in the feasibility study; eg. on p.1036:

"More importantly, the distal end of the graft failed to expand completely because one of the distal bends in the stent wire became entangled in the fabric, possibly during insertion of the graft into the delivery catheter."

The present specification (lines 30-34 on page 1) also indicates that there were problems with the prior art. The evidence before me suggests that the attachment arrangement would contribute to controlling the positioning of the graft assembly, thus overcoming the problems of the prior art. Also, the stretching effect described by Mr Hartley seems to facilitate easier withdrawal of the sheath. I am therefore satisfied that there is sufficient evidence to suggest that there are improvements and advantages over the prior art associated with the essential features of claim 1. Claim 1 is therefore is directed to an inventive step.

US Patent 4,512,338 (Exhibit GCP-6) discloses an arrangement where a graft is sewn to a shape-memory alloy wire, which upon reaching body temperature on delivery forms a coil shape to bridge a weakened portion of a body lumen. The graft is delivered by removing a sheath and holding the graft by a stiff rod with a platform at the end, in a manner similar to that described in the 170 Radiology article. It may be argued that the coil-graft assembly is at least equivalent to an "assembly comprising a graft and spring arrangement" as claimed in present claim 1, but I note that there is no part of the holding rod which extends inside the graft assembly and no attachment means between the rod and the assembly. My conclusions on the disclosure in the 170 Radiology article therefore also apply to US Patent 4,512,338.

Other citations, such as AU 78,092/91 (GCP-12) and US 4,950,227 (GCP-4), disclose arrangements where a balloon-type catheter is used to locate graft or stent, but there is no disclosure of these arrangements being used with an assembly of a graft and spring arrangement. Mr Prior argued that the graft assembly per se is not within the scope of claim 1, ie. it "is not actually there", and that this also affected the clarity and construction of the claims in general. In my view there is no objection to claim 1 in this respect; it simply extends to a monopoly for a delivery arrangement which is suitable for positioning a prosthesis assembly, which comprises a graft and spring arrangement, on the internal wall of a lumen. Thus for the claim to be anticipated, the evidence must show that the prior art is suitable for locating a graft and spring arrangement.

In paragraphs 20, 41, 43, and 48 of his declaration Dr Denton asserts that the devices described in the prior art would be suitable for delivering a spring-type assembly. I am not satisfied however that he has described in sufficient detail how this would be done. In paragraph 51 of his declaration for example, he suggests that:

"… if a graft assembly having a spring were used in the delivery system shown in Specification No.78092/91, it would be held compressed within the sheath 186 until the sheath were withdrawn"

but it is not clear to me from this statement how the assembly would be compressed to insert into the sheath, or what use the balloon catheter would have, for example.  Mr Hartley expressed his concern in paragraph 35 of his declaration; referring to the Parodi specification (GCP-12):

"… such a device would not hold an expanded device in place while the sheath is withdrawn, since as the sheath is withdrawn, the spring would expand away from the balloon, as there is no attachment to it."

The opponent's other experts do not provide any more details on this matter; they generally fail to respond in detail, in the evidence-in-reply, to the problems expressed by Mr Hartley. Paragraph 17 of Dr May's declaration in fact confirms my concerns because he expresses the view that prior art system "could deliver a self-expanding prosthesis if slight modifications were made" [my italics]; this suggests that the disclosure in the prior art is insufficient to comply with the "clear and unmistakeable directions"  requirement set out in General Tire & Rubber Co v Firestone Tyre & Rubber Co Ltd (1972) RPC 457 at pages 495 and 486.

In my view the opponent's evidence is insufficient to show that the citations teach that the balloon-catheter arrangements would be suitable for delivery of a spring-operated prosthesis. The inventions work differently: the balloon catheter delivery systems essentially involve radially-outward forces to locate the grafts, whereas the spring systems are concerned with inwardly-directed forces to retain the springs in a compressed condition. It is not clear how the balloon catheters and associated apparatus described in the citations would hold the springs in a compressed condition; eg. in US 4,950,227 it is not clear how the sleeves 18 and 20 could retain the assembly in the present invention; in my view the sleeves might get tangled with the springs and barbs.

In paragraphs 44 - 81 of his declaration, Dr Denton has carefully compared the features of the claims with disclosures in the citations. I agree with his analysis that many of the features disclosed in the citations are within the scope of the features of the present claims: there are some disclosures of integers which could be construed as an "attachment arrangement" for example. However, as indicated above, my view is that the claimed essential feature of the delivery arrangement being "for … an assembly of a graft and spring arrangement …" has not been disclosed, and for this reason I conclude that the present claims are novel in the light of these balloon-catheter systems cited against the present invention.

Re the matter of inventive step, the opponent's experts consistently allege that the balloon-type apparatus could easily be adapted for the assembly of the present invention; it being implied that such an adaptation is a "mere workshop variation" or that a person skilled in the art would have taken "routine steps" to get from the prior art to the present invention. Mr Hartley disputes these assertions but, prima facie, the weight of evidence is in the opponent's favour. I take account here also that Dr May has adduced some evidence to suggest that "there is some sort of business relationship between Mr Hartley and the applicant or companies associated with the applicant …". Dr May adduced a copy of  a brochure for a prosthesis known as the Zenith AAA; the brochure is produced by the Cook group of companies and Mr Hartley is mentioned in  a list of acknowledgements in the brochure. At the hearing the applicant did not dispute that there is some association between it and Mr Hartley. Generally it can be argued that evidence from a non-independent party is likely to have less probative value than evidence from an independent party, so I think it is appropriate that I somewhat reduce the probative value of Mr Hartley's evidence.

On the other hand I think it is appropriate that I also somewhat devalue the opponent's evidence-in-reply because in many respects it is not in reply to the evidence-in-answer. There are a few references to Mr Hartley's comments, but Dr Fletcher's and Dr May's evidence is mainly supporting comments made by Dr Denton, without additional comment on Mr Hartley's views, and in this respect should have been adduced as evidence-in-support. (It is possible that if these other declarations had been part of the evidence-in-support then the applicant may have felt it necessary to balance this with more evidence-in-answer).

Another factor to consider in the matter of inventive step is the opponent's experts lack of detailed explanation of how the balloon-type devices could be adapted to deliver a spring-type prosthesis assembly. As stated above, many of Mr Hartley points on the problems associated with such an adaptation are not discussed by the opponent's experts. It is not clear to me what routine steps would have been taken to get from the prior art to the present invention.

Taking all these matters into account I am not satisfied that the opponent has adduced sufficient evidence to prove that the present invention lacks an inventive step in the light of the citations relating to balloon-type delivery arrangements.

I now refer to European Patent EP 472,731 (Exhibit GCP-5). This specification relates to an invention very similar to the present invention: an assembly of a graft attached to a set of resilient wire rings is used. The copy of the published patent in the evidence indicates that its publication date was 22-8-1991, ie. earlier than 25-10-1991, the earliest of the three priority dates of the present claims. 

I will now compare the disclosure of EP 472,731 specifically with the essential features of present claim 1, and claim 2. Noting particularly the disclosure in columns 7, 8, 10 and 11 and figures 5, 12 and 13 of the citation, it is my view that:

• a graft assembly is disclosed by the artificial blood vessel 7,

• an outer sheath is disclosed by the catheter 8,

• an elongated retaining means extended within the assembly is disclosed by the flexible tube 2,

• an attachment arrangement is disclosed by the string 4, noting that it links the tube 2 and the assembly,

• the attachment arrangement is attached at the distal end, which is the end opposite the direction of withdrawal of the sheath, ie. the same as in the present invention.

Therefore all the essential features of claims 1 and 2 are disclosed in the EP patent; the claims are therefore not novel and lack an inventive step in the light of this citation.

Claim 3 is characterised by a dilator head. The specification indicates, eg. on page 17, that some embodiments of the invention do not use a dilator head, and indicates elsewhere that standard dilator heads may be used with some embodiments. The specification and the evidence generally suggest that the dilator head is a commonly used integer in this type of apparatus and that it is not an essential feature of the invention. It could be argued that the dilator head is an essential feature of Claim 3 and that claim 3 would therefore be novel if the feature was not disclosed in the citation. However, I do not think it is necessary for me to decide whether the feature is an essential feature of the claim; suffice to say that in my view there is no inventive ingenuity involved in the normal use of a dilator head in this case. Claim 3 therefore lacks an inventive step over the EP citation.

Claim 4 is characterised by a "contraction arrangement" and by a "disabling arrangement". The former is disclosed by the collapsing device and associated apparatus shown in figures 7 - 11 in the citation, but there is no disclosure of a disabling arrangement which "is provided for expandably releasing the said assembly …". When released, the string 4 and wire 3 arrangement disclosed in the EP patent allows removal of the flexible tube 2 (column 11), but it does not prevent expansion of the spring assembly, which occurs as the sheath is removed. Thus claim 4 is novel in the light of this citation. I have little evidence before me specifically on the differences between present claim 4 and EP 472,731, so I think it is appropriate to conclude that claim 4 also involves an inventive step in the light of this patent.

Claims 7, 10, 11 and 12 can be appended to claim 3 which I have found lacks an inventive step in the light of EP 472,731. My brief comments on these other appended claims are as follows:

• Claim 7 is novel and involves an inventive step because it is directed to a substantive embodiment of the present invention, and the citation does not envisage any arrangement for a bifurcated graft.

• The barbs referred to in claim 10 I think are an important feature of the present invention and this feature would be an essential feature of a potentially independent claim. The citation does not disclose the use of barbs so claim 10 is novel, however, based on the opponent's evidence, it is my view that a person skilled in the art could easily adapt the arrangement in the citation to be used with a barbed assembly. Claim 10 therefore lacks an inventive step over this prior art.

• The sealing feature in Claim 11 seems to be a commonly used device in this type of apparatus; I have no evidence to suggest that there is any inventive ingenuity involved in the sealing arrangements in the present invention, so claim 11 lacks an inventive step over EP 472,731.

• Claim 12 is a narrowly defined omnibus claim; I am satisfied that the embodiments of the invention shown in the drawings, and as claimed, are novel and involve an inventive step.

I now refer to US Patent No. 5,151,105 (Exhibit GCP-10). This patent specification also relates to an invention for delivering an assembly of a graft attached to a set of resilient springs- annular torsion springs at the ends of the assembly, with longitudinal stiffener springs or a coiled wire spring providing support between the ends.

The US patent has a priority date of 7-10-1991, thus being earlier than the earliest priority date of the present claims, but the patent was published on 29-9-1992, ie. after the earliest but before the third claimed priority date of the present claims. Before I decide whether the present claims are entitled to their priority dates I will first compare the disclosures in the citation with present claims 1 and 2. 

The opponent suggested that "positioning wires" 34 and 36 described in US Patent No. 5,151,105 could be construed as the "retaining means" of the present claims. In my view this is going beyond the disclosure in the citation: even though it could be argued that one of the positioning wires "is temporarily positioned near the proximal end of the … assembly", the purpose of the positioning wires is to provide fine tuning positioning after the assembly is located in position in the aorta; their purpose is not to "retain the assembly in position whilst the outer sheath is being removed".

The retaining function in fact seems to be provided by the catheter 24, which can also be construed as a “means for retaining the … assembly at the particular location …” and as "an elongated member to be extended within the said assembly". Given the catheter 24 as the retaining means, the mechanism comprising the end hole 46 in the end of band 42 and the end 28 of guide wire 26 could be construed as an “attachment arrangement” of sorts, at the distal end. However, I do not think it can be said that this attachment arrangement either (i) is “temporarily attached to the … assembly”, or (ii) "extends between" the elongated member and the assembly. These essential features of present claims 1 and 2 are therefore not disclosed in the citation. The inventions are also sufficiently different for me to be satisfied that there is an inventive step in the present invention in the light of the invention disclosed in the citation.

Given my conclusion that the present claims are novel and involve an inventive step in the light of US Patent No. 5,151,105, it is therefore not necessary that I determine whether the present claims are entitled to their claimed priority dates.

The other patent specifications cited in the opponent's evidence are not as closely related to the present invention as the cited patent specifications already discussed, so I think it is not necessary for me to discuss them in detail.

FURTHER EVIDENCE

The opponent's application under Reg. 5.10(4) is included in a letter dated 10 August 1999 from its patent attorney. It indicates that "the nature of the further evidence is to show that there is a link between the declarant in the evidence in answer, David Hartley, and the patent applicant, Cook Incorporated." The application indicates that the evidence includes copies of two PCT applications and the results of a search, which supposedly show some link between the said parties. Mr Prior states that it occurred to him during final preparation of the case for hearing that Mr Hartley "may have been involved with some patent applications in which the applicant or an associated company has an interest."

The criteria for considering further evidence are set out in paragraph 6.1.4 in Chapter 6 of Vol.3 of the Patent Office Manual of Practice and Procedure.  After the hearing on the further evidence I decided that it was appropriate to wait until I was fully involved in the process of considering all the evidence adduced in the main opposition before deciding whether I would grant leave to serve the further evidence; in that way I could better determine whether the evidence would have an important influence on the result of the opposition.

As stated earlier, Dr May, in Exhibit JM-2 accompanying his declaration in the evidence-in-reply, provides some evidence of a link between Mr Hartley and the applicant; the applicant did not contest this evidence, so I decided to somewhat devalue some of Mr Hartley's evidence accordingly. Under these circumstances I don't think it is necessary to have any more evidence leading me in the same direction; it would be superfluous; the evidence already adduced is fairly indicative of there being some link between the parties. More evidence in this regard might provide a further degree of certainty, but even so, I would not entirely disregard Mr Hartley's evidence, since it is common practice for experts directly associated with a party to an opposition to give evidence. In fact, sometimes the best evidence comes from such parties.

Thus I formed an opinion during analysis of the main opposition evidence that any further evidence linking Mr Hartley to the applicant would not contribute to a more correct, just, or expeditious result. Also, I think Mr Prior's reasons for preparing the evidence at a relatively late stage in the opposition proceedings are not very convincing; presumably, if he'd thought of doing the search earlier, the evidence could have been prepared at the time of Dr May's declaration. Taking all these matters into account, I refuse the application to adduce further evidence.

CONCLUSION

The S.59 opposition to grant of a patent is successful because I have found:

• that there are S.40 objections to the applicant's specification, ie. claims 1-3 do not define the invention and are not clear, the characterising features of the invention are not fully described, and the broadest form of the invention is not fully described, and

• with a prima facie construction of claim 1 that the feature of the retaining means being temporarily positioned near the proximal end of the assembly is an inessential feature, then

• claims 1 and 2 are not novel and claims 1, 2, 3, 10 and 11 lack an inventive step.

However, in my view there is patentable subject matter in the applicant's specification, so I allow Cook Incorporated sixty days from the date of this decision to propose amendments to overcome the objections to the specification.

I have also refused Endo Vascular Technologies' application to serve further evidence.

Both parties sought costs in these matters. The usual practice in oppositions is to award costs against the losing parties; I see no reason to change that practice in this case so I award costs in accordance with Schedule 8 against Cook Incorporated in the S.59 opposition and against Endo Vascular Technologies in the matter of the further evidence.

John Welsh
Delegate of the Commissioner of Patents

Patent attorneys for the applicant  : Collison & Co, Adelaide

Patent attorneys for the opponent  : Davies Collison Cave, Melbourne