T 0379/20 28-03-2023

1. Main request - Added subject-matter - Article 100(c) EPC

The subject-matter of claim 1 extends beyond the content of the application as originally filed.

1.1 The appellant submitted that claim 1 as granted was a combination of the features of claim 1 as filed with further features of the embodiment of figures 8/9.

They argued that claim 1 as originally filed was not solely related to the embodiment of figures 16/17, but also covered the embodiment of figures 8/9, such that the combination of claim 1 as filed with the added features relating to the embodiment of figure 8/9 did not extend beyond the content of the application as originally filed.

1.1.1 Firstly, while the functional feature,

"wherein the at least two commissure extensions are secured to the V-shaped structures of the stent structure with attachment material that is slideable along the V-shaped structures (54) of the stent structure to allow for free movement of the valve relative to the stent structure along its longitudinal axis"

was only described in the description in detail in the context of the embodiment of figures 16/17, this did not limit claim 1 to said embodiment. There was no teaching in the original disclosure that would contradict the presence of the above functional feature of original claim 1 in the embodiment of figures 8/9. In fact, the embodiment of figures 8/9 showed each structural feature of claim 1 as originally filed, including the specific V-shaped structures and the attachment material, which was required to realise the functional feature that the attachment material was "slidable along the stent structure to allow for free movement of the valve relative to the stent structure along its longitudinal axis".

1.1.2 Secondly, the embodiment of figures 8/9 was the first embodiment "in accordance with the invention" that was presented in the description (see paragraphs [0020], [0040]). An unbiased skilled reader would expect this very first embodiment of the invention to be covered by at least one claim of the application as originally filed, if not by the first claim of the application as originally filed (this assumption was supported by Rule 43(3) EPC). However, the second original independent claim 9 required a "tubular tissue material... extending beyond the outflow end of the stent", which was not realised in the embodiment of figures 8/9. Thus, if claim 1 would not also relate to the embodiment of figures 8/9, then this very first embodiment of the application that was "in accordance with the invention" would not be covered by any of the original claims. While this situation may theoretically not be excluded, it was highly unlikely. The appellant re-emphasised that it was possible to realise all features, in particular also that of a slidable attachment material, in the embodiment of figures 8/9.

The fact that the scalloped areas of the prosthesis were not attached in figures 8/9 and the fact that the prosthesis was attached at the inflow end did not affect in any way the attachments of the stitches at the V-shaped structures. There was no teaching in the application as filed that would contradict to realise the stitches at the V-shaped structures of figures 8/9 the same way as in figures 16/17.

1.1.3 Thirdly, paragraph [0010] disclosed the invention namely: "A bioprosthesis can be attached to the wires of this stent in certain, predetermined locations and preferably will be sewn to the wires in such a way that the material from which the bioprosthesis is made will not be damaged during compression and/or expansion of the stent and attached bioprosthesis". The invention lied in the at least two commissure extensions secured to the V-shaped structure of the stent with attachment material that is slideable to allow for free movement of the valve relative to the stent structure along its longitudinal axis. The skilled person would understand that this also applied to the embodiment of figures 8/9.

Furthermore the skilled reader was even explicitly taught in paragraph [0050] of the application as originally filed that the attachment systems described in subsequent paragraphs (which included paragraph [0056] directed to the embodiment of figures 16/17) could be used with the stent configurations described in the preceding paragraphs (which included paragraphs [0040] and [0041], and thus the embodiment of figures 8/9).

1.1.4 Summarising the above, even though the slidable attachment was not again recited in the context of the embodiment of figures 8/9, there was no teaching that contradicted the presence of said feature in this embodiment, it was technically possible in this embodiment, the same beneficial effect would be achieved, and only in this interpretation would the embodiment of figures 8/9 be covered by any of the original claims.

1.2 The Board does not agree. Claim 1 is a combination of features from the embodiment of figures 8/9 and from the embodiment of figures 16/17 that could not be derived directly and unambiguously by the skilled person, using common general knowledge from the application as filed.

1.2.1 The Board notes that the slidable stitches along the V-shaped structures to allow for free movement of the valve relative to the stent structure along its longitudinal axis, defined in independent claim 1,

is only explicitly disclosed in paragraph [0056] of the WO application relative to the embodiment of figures 16/17. In this embodiment both the scalloped openings and the commissure extensions are attached to the stent. The stitches are slidable along the V-shaped structures to minimise stress on the stitches when the stent expands.

The embodiment of figures 8/9 is designed differently, the commissure extensions of the bioprosthesis are stitched to the V-shaped structure while the scalloped openings are not stitched to the stent. The bioprosthesis 40 further includes material 48 that covers at least a portion of the inflow end 42 of the bioprosthesis. The material 48 extends over the edge or end of the bioprosthesis and into the interior tubular surface. The stent comprises a series of wires arranged in a generally tubular shape including multiple diamond-shaped structures 52 at its inflow side to which the bioprosthesis is secured by suturing the covering material and/or tubing material in a zigzag pattern.

There is no direct and unambiguous disclosure in the application relative to the embodiment of figures 8/9 that the commissure extensions are secured to V-shaped structures of the stent "with attachment material that is slideable along the V-shaped structure of the stent structure to allow free movement of the valve relative to the stent structure along its longitudinal axis".

1.2.2 Firstly there is no explicit disclosure in paragraph [0040] and [0041] relative to the embodiment of figures 8/9 of the above-mentioned functional feature.

1.2.3 Secondly paragraph [00010], under "summary" of the WO application, does not disclose that slidable attachment of the commissure extensions to the V-shaped structure is the solution to the problem to be solved as alleged by the appellant. Paragraph [00010] discloses that the attachments of the bioprosthesis should be made at predetermined locations and in such a way that the material of the bioprosthesis will not be damaged during compression and/or expansion of the stent. Paragraph [00010] then specifies that "the stent includes three commissure attachment areas, where each of these areas is used as connection location for one of the commissure extensions of a bioprosthesis". In view of paragraph [00010], the skilled person would not derive that all the embodiments described in the application use slidable stitches to attach the commissure extensions of the bioprosthesis to the stent.

1.2.4 Thirdly paragraph [0050] reads: "A number of systems, components, and devices are described below for attachment of valve material (e.g., tissue leaflets) within the interior area of a stent structure. It is understood that the systems that are shown and described herein for this purpose can be used with stent configurations described above and/or other stent constructions".

This paragraph is very broad and does not specify that the slidable attachment of the embodiment of figures 16/17 applies to the embodiment of figures 8/9. No indication is given as to which feature from which embodiment is to be used with other embodiments. Paragraph [00050] is, similar to paragraphs [0008] and [00060] of the application, a general statement that features of different embodiments can be combined. From these paragraphs the skilled person cannot derive any direct and unambiguous teaching.

1.2.5 Fourthly the question whether the skilled person would have an incentive to secure the commissure extension in a slidable manner to the stent structure of figures 8 and 9 is not a criterion for assessing added subject-matter. The criterion is whether the skilled person would derive the combination of features of claim 1 directly and unambiguously, using common general knowledge, from the whole of the documents as filed. While it may be possible technically to secure the commissure extensions to the V-shaped structure with attachment material that is slidable along the V-shaped structures to allow for a free movement of the valve relative to the stent structure along its longitudinal axis, there is not teaching to do so for the embodiment of figures 8/9. Furthermore, should the skilled person want to reduce damages of the bioprosthesis material when the stent to which it is attached undergoes compression and/or expansion, various technical solutions exist such as for example attaching the valve to the stent in a loosen/slacking manner.

1.2.6 Fifthly there is no reason to assume that the claims of the application as filed cover all the embodiments of the invention. For example, an applicant may choose to disclose embodiments without any corresponding claim in the application as filed and file at a later stage a divisional application regarding these embodiments. Furthermore, it is not because an embodiment is disclosed as being "in accordance with the invention" that it is necessarily claimed.

The appellant makes reference to Rule 43(3) EPC. However, Rule 43(3) EPC deals with the form and content of the claims and does not support the assumption made by the appellant that the claims as originally filed cover all the embodiments disclosed in the application as filed.

1.2.7 To conclude there is no direct and unambiguous disclosure of the stitches being slidable along the V-shaped structures for the embodiment depicted on figures 8/9 (corresponding to paragraph [0040] and [0041]) and the skilled reader would not consider that slidable stitches disclosed with the embodiment of figures 16/17 would implicitly apply for the embodiment of figures 8/9.

2. First to seventh auxiliary requests - Added subject-matter - Article 123(2) EPC

The subject-matter of claim 1 of the first to the seventh auxiliary requests extends beyond the content of the application as filed for the same reasons as for the main request and therefore does not fulfill the requirements of article 123(2) EPC.

Claim 1 of the first auxiliary request corresponds to claim 1 of the main request. As to claim 1 of the second to the seventh auxiliary requests, they all comprise additional features relating to the embodiment of figures 8/9 compared to claim 1 of the main request. However the features relating to the embodiment of figures 16/17 remains in claim 1, such that the subject-matter of claim 1 is a combination of two embodiments that was not disclosed in the application as filed.