T 1794/16 20-10-2022

1. The invention

The invention relates to a surgical stapler, which is typically used in laparoscopic or endoscopic procedures for stapling together and then splitting tissue. Figures 1A, 1B, 4 and 13 of the patent, reproduced below, illustrate a surgical stapler according to the invention.

FORMULA/TABLE/GRAPHIC

FORMULA/TABLE/GRAPHIC

FORMULA/TABLE/GRAPHIC

The surgical stapler comprises a tool assembly (100) with an anvil assembly (110) and a cartridge assembly (200) mounted in a channel assembly and having a plurality of staples, the anvil assembly and the cartridge assembly having an open position and an approximated position.

As explained in the description, the tissue to be treated can first be clamped between the anvil assembly and the cartridge assembly by moving the assemblies from an open to an approximated position and then cut through along a longitudinal direction of those two components. At the same time the tissue is cut, two rows of staples can be applied at each side of the cut.

The claimed invention also features a dynamic clamping member (150) with an upper camming surface and a lower camming surface riding between the anvil assembly and the cartridge assembly and a clamping collar (140) to move the anvil assembly and the cartridge assembly between the open and the approximated positions.

2. Sufficiency of disclosure

2.1 The opponent submitted that the subject-matter of claim 1 of the main request was not sufficiently disclosed because the feature "heavy gauge material" was so ill-defined that it was impossible to establish whether a certain anvil assembly lay within the scope of the claim.

The patent explains that the "heavy gauge material" of the anvil assembly could be "301 surgical stainless steel" or other high-strength and durable materials (paragraph [0029]). Therefore, the person skilled in the art receives teaching on the properties of the material of the anvil assembly. As regards the required thickness of the material, implied by the qualifier "heavy gauge" in the opponent's view, this is not specified in the patent. However, the person skilled in the art understands that this must be such for the surgical stapler to effectively perform its function. Hence, on the basis of the disclosure of the patent, the required thickness can easily be established in view of common general knowledge and, if needed, with some trial and error.

It follows that whether it can be established with certitude if a certain anvil assembly lies within the scope of the claim, as the opponent argued, is at most a matter of clarity in this case, in accordance with T 593/09, point 4.1.4 of the Reasons. Objections of lack of clarity which do not arise owing to amendments cannot be considered by the Board in opposition appeal proceedings (G 3/14, order).

2.2 The opponent, while not disputing that it was possible to carry out the invention according to the embodiments described in the description, submitted that the subject-matter of claim 1 of the patent as granted was not sufficiently disclosed because it also encompassed non-described embodiments in which the dynamic clamping member could be moved before the clamp collar.

2.3 The Board does not accept this argument.

2.4 First, claim 1 of the patent in suit does not recite that the dynamic clamping member could be moved before the clamp collar. Moreover, as the proprietor argued, the claim itself states that the anvil assembly and the cartridge assembly are approximated by the clamp collar and that the dynamic clamping member slidingly engages the anvil slot and the cartridge assembly "to oppose expansive forces associated with clamping and stapling tissue".

Since such expansive forces are a consequence of the approximation, it is at least questionable that the non-described embodiments referred to by the opponent fall within the scope of the claim.

2.5 In any case, Article 83 EPC requires that the invention be disclosed in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art. In view of this article, it is not problematic that claims - as is typically the case - represent a generalisation of the teaching of the description and the drawings.

Decision G 1/03, point 2.5.2 further establishes that a claim might encompass non-working embodiments and still be allowable as long as the specification "contains sufficient information on the relevant criteria for finding appropriate alternatives over the claimed range with a reasonable effort". Point 2.5.2 of G 1/03 refers to the case law represented by, for instance, T 301/87, according to which "it is not necessary for the purpose of Articles 83 and 100(b) EPC that the disclosure of a patent is adequate to enable the skilled man to carry out all conceivable ways of operating the invention which are embraced by the claims" (point 3.2). T 515/00, cited by the proprietor, comes to the same conclusion.

2.6 In the current case, the patent discloses how to put into practice a tool assembly with a clamp collar and a dynamic clamping member in accordance with claim 1 and, for example, paragraphs [0026], [0033] and [0034] and Figures 11B and 13. In respect of the movement of the dynamic clamping member and the clamp collar addressed by the opponent, the patent as a whole explains the advantages of performing gross approximation of the anvil assembly and the cartridge assembly, using the clamp collar, and fine approximation via the dynamic clamping member, to oppose expansive forces associated with clamping and stapling tissue (paragraphs [0027] and [0030]). Since the tissue is stapled only after the anvil assembly and the cartridge assembly have been approximated, the person skilled in the art is consistently taught to carry out the invention with the clamp collar arranged to move and perform gross approximation before the dynamic clamping member is moved. In view of this teaching, which allows achieving the advantages explained in the patent, the person skilled in the art can put into practice the invention as defined in claim 1.

2.7 It follows that the ground for opposition of insufficiency of disclosure (Article 100(b) EPC) raised by the opponent does not prejudice the maintenance of the patent on the basis of the main request.

3. Extension of subject-matter

The original application and the other parent applications contain the description, drawings and claims of the first parent application as filed (the claims in the form of clauses at the end of the description). It follows that extension of subject-matter can be assessed only by referring to the first parent application as filed.

In the first parent application as filed, the subject-matter of claim 1 of the main request is based on (i) for the definition of the tool assembly: the paragraph bridging pages 6 and 7; page 14, second paragraph to page 15, first paragraph; the paragraph bridging pages 18 and 19; and page 24, first full paragraph; (ii) for the definition of the dynamic clamping member: the paragraph bridging pages 19 and 20; and the paragraph bridging 28 and 29; and (iii) for the definition of the clamping collar: the paragraph bridging pages 15 and 16.

3.1 The opponent argued that the subject-matter of claim 1 of the main request included added subject-matter because it comprised a number of intermediate generalisations.

The Board notes that intermediate generalisations arising from the omission of features in an originally disclosed combination are allowable if there is no technically inextricable link between the omitted features and the claimed features extracted from the combination. This is not in contrast with T 416/86 (point 2.1 of the Reasons), cited by the opponent. The absence of an inextricable link implies a direct and unambiguous teaching to the person skilled in the art, who is left in no doubt (in accordance with T 113/86 cited by the opponent) that features equivalent to the omitted ones - and part of the common general knowledge - can equally be used for the technical functions of the claimed features extracted from the combination.

3.2 As explained above, a clamping collar for moving the anvil assembly and cartridge assembly between the open and approximated positions is disclosed in the paragraph bridging pages 15 and 16 of the first parent application as filed. One of the opponent's objections relates to the omission in claim 1 of the main request of camming surfaces of the anvil for cooperation with the clamping collar.

However, the person skilled in the art understands that what is technically important for the function of the clamping collar is the possibility of moving the anvil assembly and the cartridge assembly from and to the approximated position. Nowhere are camming surfaces of the anvil presented as essential for the function of the clamping collar in the first parent application as filed. The paragraph bridging pages 15 and 16, which describes the operation of the claimed invention, does not mention camming surfaces of the anvil. As the proprietor pointed out, the person skilled in the art directly and unambiguously understands, on the basis of this passage, that the movement of the anvil assembly and the cartridge assembly from and to the approximated position could equally be achieved by a number of different elements of the clamping collar, the anvil and/or the cartridge assembly. Hence, there is no inextricable link between the omitted camming surfaces and the features of claim 1 of the main request.

3.3 The upper camming surface of the dynamic clamping member is disclosed in the paragraph bridging pages 28 and 29. The opponent objected to claim 1 of the main request omitting that the upper camming surface of the dynamic clamping member was disposed in a longitudinally disposed, elongated cross or T-shaped slot in the anvil assembly.

It is true that claim 1, while stipulating that the anvil assembly has a longitudinally disposed slot, does not define the shape of the slot. However, the engagement of the upper camming surface of dynamic clamping member with the anvil assembly, as shown in the embodiment according to Figure 5 and discussed in the paragraph bridging pages 21 and 22 of the first parent application as filed, is merely preferred. Indeed, the second paragraph on page 6 describing the interaction of the camming surface and the slot does not specify the shape of the slot. It is thus clear to the person skilled in the art that several shapes of the slot are possible for the interaction with the upper camming surface of the dynamic clamping member. Hence, this objection is not convincing either.

3.4 While the dynamic clamping member is disclosed in claim 1 of the first parent application, the features of the clamping collar were added during the examination proceedings. The opponent asserted that this addition represented an unallowable intermediate generalisation because claim 1 of the main request did not prescribe that the clamping collar acted to approximate the anvil assembly and cartridge assembly before the dynamic clamping member was moved. This added subject-matter.

As explained in point 2.2, second paragraph above, the opponent's assertion that this feature is missing from current claim 1 is questionable. In any case, disclosure for the clamping collar can be found not only in the above-mentioned paragraph bridging pages 15 and 16 but also in the claims of the first parent application as filed (claims 6, 11, 17). These claims do not specify the order of movement of the clamping collar and the dynamic clamping member. Hence, the addition of the features of the clamping collar without explicitly specifying the order of movement of the clamping collar and the dynamic clamping member does not represent an intermediate generalisation, let alone an unallowable one.

3.5 The opponent also argued that the omission of a sled in claim 1 of the main request added subject-matter.

While the opponent is right that a sled is present in every claim of the first parent application as filed, the Board notes that on page 16, last paragraph of the first parent application as filed, it is directly and unambiguously explained that the function of the sled could be taken over by the dynamic clamping member itself. The sled is first described as including cam wedges for camming surgical fasteners into and through tissue when the sled is actuated to move by the user. Then it is explained that the dynamic clamping member is associated with the sled, for example being integral with it, and can move with the sled. Finally, it is disclosed that the dynamic clamping member itself could have the cam wedges. With such an arrangement, the presence of the sled is clearly not needed.

The opponent's argument that the sled restricted the movement of the dynamic clamping member and was essential for its longitudinal movement and for providing a uniform gap between the anvil assembly and the cartridge assembly is a mere allegation not derivable from the first parent application as filed. On the contrary, on the basis of page 16, last paragraph, the sled is directly and unambiguously disclosed as an optional feature. Its omission from claim 1 of the main request does not add

subject-matter.

3.6 It follows that the objections of added subject-matter (Articles 76(1), 123 (2) and 100(c) EPC) raised by the opponent do not prejudice the maintenance of the patent on the basis of the main request.

4. Inventive step

4.1 The opponent argued that the subject-matter of claim 1 of the main request lacked an inventive step starting from E1.

E1 discloses a surgical stapler with an actuation mechanism for performing gross approximation of a pair of jaws (see Figures 3, 12, 13, 15 and 16 reproduced below and paragraph [0035], second and third sentence).

FORMULA/TABLE/GRAPHIC

FORMULA/TABLE/GRAPHIC

FORMULA/TABLE/GRAPHIC

FORMULA/TABLE/GRAPHIC

FORMULA/TABLE/GRAPHIC

According to E1, which is specifically related to the treatment of gastro-oesophageal lesions (paragraph [0001] and Figures 1, 2c, 11, 21 and 22), the actuation mechanism for performing gross approximation is in the form of a cable 44 at the distal end of the stapler. According to one embodiment, the surgical stapler comprises a clamping member (60) in the form of a clamping collar for performing fine approximation of the jaws (paragraph [0036]).

E1 does not directly and unambiguously disclose a clamping collar for moving an anvil assembly and a cartridge assembly between open and approximated positions as defined in claim 1 of the main request.

E1 expressly states that clamping member 60 is actuated to "finely approximate the jaws" (paragraph [0036]). This is done after the jaws are grossly approximated (paragraph [0035], first sentence).

Only the gross approximation - not the fine approximation - can be considered the movement from an open position to an approximated position as defined in claim 1: the position of the jaws after the gross approximation is not an "open" position in the technical context of a surgical stapler. For the person skilled in the art, a surgical stapler in an open position must allow the surgeon to readily introduce tissue between its jaws. The description of the patent is consistent with this interpretation. According to column 7, lines 50 to 58, moving the anvil assembly and the cartridge assembly into the grossly approximated position will cause the assemblies to grasp tissue. This means that in the grossly approximated position, the surgeon cannot introduce any more tissue between the assemblies.

The possibility of using a clamping collar as defined in claim 1 of the main request, which inherently acts on the proximal side of the tool assembly, for moving the anvil assembly and the cartridge assembly between open and approximated positions instead of a cable at the distal side of the tool assembly as disclosed in E1 has the technical effect that in the open position tissue can be inserted between the cartridge assembly and the tool assembly from the distal side of the tool without hindrance.

This solves the objective technical problem of facilitating the manipulation of tissue.

It is accepted that both E4 and E5 disclose a clamping collar for moving an anvil assembly and a cartridge assembly between open and approximated positions.

However, E4, E5 or any of E2, E3 and E6 to E8 referred to by the opponent do not disclose a mechanism for performing gross approximation first followed by fine approximation like the one disclosed in E1. The clamping collars disclosed in E4 and E5 are used to perform a one-step approximation.

The opponent's argument that it would have been routine practice to replace the cable and its activation mechanism in E1 with a clamping collar as disclosed in E4 or E5 is not accepted. The person skilled in the art would have received no teaching to replace an element of the two-step approximation mechanism of E1 from documents which do not disclose such a mechanism and do not address this part of the objective technical problem. The person skilled in the art could have simply replaced the whole mechanism of E1 with a mechanism according to E4 or E5 in view of the objective technical problem.

Hence, starting from E1 in combination with any of E2 to E8, the subject-matter of claim 1 of the main request would not have been arrived at in an obvious way.

4.2 The opponent submitted that the subject-matter of claim 1 of the main request lacked an inventive step when starting from E4 or E8 in combination with E1, E2, E3 or E7.

It is common ground that both E4 and E8 disclose surgical staplers with a clamping collar for moving an anvil assembly and a cartridge assembly between open and approximated positions, but neither E4 nor E8 discloses a dynamic clamping member as defined in claim 1.

The objective technical problem solved by the dynamic clamping member is to provide a more accurate and stable stapling mechanism. This is due to the dynamic clamping member having a central support and upper and lower camming surfaces slidingly engaging the anvil assembly and the cartridge assembly respectively. This has the technical effect of opposing expansive forces associated with clamping and stapling tissue.

In accordance with one embodiment, E1 discloses a dynamic clamping member as defined in claim 1 of the main request in the form of an I-beam (70) with camming surfaces 82a and 82b.

However, E1 teaches a tool assembly for

gastro-oesophageal lesions. Cable 44 disclosed in E1 is of no hindrance for the field of application of E1 but would make the assembly of E4, directed also to the treatment of blood vessels, useless because it would hinder the introduction of tissue from the distal side of the assembly. Moreover, the mechanical design of the clamping mechanisms of E4 and E8 would make it difficult to implement only the I-beam of the approximation mechanism disclosed in E1. E1 does not disclose a clamping collar for performing gross approximation. Finally, there is no teaching in E1 on the objective technical problem.

It is also accepted that each of E2, E3 and E7 discloses a surgical stapler with a dynamic clamping member as defined in claim 1 of the main request, as the opponent argued.

However, these documents do not disclose any clamping collar for moving an anvil assembly and a cartridge assembly between open and approximated positions. According to these documents, the dynamic clamping members are the only elements that move jaws of a surgical stapler between open and approximated positions (Figure 45 of E2, Figure 11 of E3 and Figure 7 of E7). The dynamic clamping members are not taught to solve the problem of providing a more accurate and stable stapling mechanism. E2, E3 and E7 do not suggest that the clamping should be performed by two distinct elements.

Consequently, the skilled person would not provide dynamic clamping members as disclosed in E2, E3 or E7 in the devices of E4 or E8 and, at the same time, keep the clamping collars, which are taught to perform the same function.

Hence, the subject-matter of claim 1 of the main request is inventive in view of the combination of E4 or E8 with E1, E2, E3 or E7.

4.3 The opponent also submitted that the subject-matter of claim 1 of the main request lacked an inventive step over the combination of E2 with E4.

E2 does not disclose a clamping collar as defined in the claim.

The problem solved by the clamping collar is to provide a more accurate and stable stapling mechanism. This is due to the initiation of and the contribution to the clamping action by the clamping collar.

E4 discloses a clamping collar as defined in claim 1 of the main request. However, according to E4, the clamping collar is the only element that moves the anvil assembly and the cartridge assembly between the open and approximated positions. E4 does not teach that the clamping collar could address the problem of providing a more accurate and stable stapling mechanism. E4 does not suggest that the clamping should be performed by two distinct elements.

Consequently, the person skilled in the art would have no motivation to provide a clamping collar in addition to the dynamic clamping member of E2.

Hence, the subject-matter of claim 1 of the main request is inventive in view of the combination of E2 with E4.

4.4 It follows that the objections of lack of inventive step (Article 56 EPC) raised by the opponent do not prejudice the maintenance of the patent on the basis of the main request.

5. The proprietor filed an amended paragraph of the description to bring it into conformity with the claims of the main request. The opponent had no objections to this amendment. The Board does not have any either.