T 1424/23 24-11-2025

1. Application

1.1 Atherosclerosis is characterised by the build-up of fatty deposits (atheromas) in the intimal layer of a patient's blood vessels. Often, these atheromas harden and become calcified. They create stenoses in the vessels and restrict the flow of blood.

1.2 Atherectomy refers to the removal of the obstructing material, i.e. atheroma, from blood vessels. Rotational atherectomy is one way to perform atherectomy in a vessel. Rotational atherectomy devices are used for removing calcified atherosclerotic plaque from arteries. They typically comprise a drive shaft with a burr and an abrasive material (e.g. diamond particles) on the surface of a burr. The burr is rotated at high speed within the vessel while it is advanced across the stenosis.

1.3 The application relates to high-speed rotational atherectomy devices.

1.4 An idea underlying the application is to achieve an orbital rotational motion of an abrasive element in order to open a stenosis to a diameter larger than the resting diameter of the abrasive element. One way to achieve this is to provide the abrasive element eccentrically on a drive shaft, such that its centre of mass is radially offset from the rotational axis of the drive shaft, combined with counterweights also disposed eccentrically on the drive shaft. This allows the use of a smaller-diameter abrasive element to open a stenosis to a diameter equivalent to that achieved by known larger-diameter abrasive elements (see, for example, paragraphs [073], [089], [0094] and [095] of the application as filed).

1.5 Claim 1 of each of the requests on file defines a high-speed rotational atherectomy device comprising a guide wire, a drive shaft, an eccentric abrasive element disposed on the drive shaft, and counterweights disposed on the drive shaft.

2. Preliminary remarks on Article 123(2) EPC

2.1 The decision under appeal discusses the amendments made to claim 1 compared to the amended claim 1 filed on entry into the European phase. Moreover, the statement of grounds of appeal makes the argument as to why these amendments (compared to the amended claim 1 filed on entry into the European phase) find a basis in the application as filed.

2.2 However, when assessing compliance of a European patent application with Article 123(2) EPC, it has to be established whether or not the application has been amended in such a way that it contains subject-matter which extends beyond the content of the application as filed.

2.3 As stated in points 1.4 and 1.5 of the Reasons of G 3/89, the content of the application as filed consists of the description, claims and drawings as filed, i.e. on the filing date. In this case, the application as filed was published with the international application number WO 2017/165013 A1 ("application as published"). The 35 claims there are the claims of the application as filed.

2.4 The claims filed on entry into the European phase do not correspond to those of the application as filed. Therefore, the claims filed on entry into the European phase do not provide a basis for assessment of the compliance of the amendments with Article 123(2) EPC.

3. Main request (filed as "2**(nd) auxiliary request" during the oral proceedings before the examining division) - Article 123(2) EPC

3.1 The contested decision found that the feature "wherein the high-speed rotational atherectomy device comprises more than two counterweights" resulted in added subject-matter. This is the only reason why the current main request (then 2nd auxiliary request) was found not to be allowable.

3.2 Paragraph [0079] of the application as published defines a counterweight as an element located on the drive shaft either proximal or distal to an abrasive element. This also reflects how the term "counterweights" in the above feature of claim 1 would be construed by a person skilled in the art.

3.3 Paragraph [0079] also refers to a system "with two or more counterweights", albeit further specifying that in that system "the distances between each counterweight and the abrasive element are not equal", a feature which is absent from claim 1 of the main request.

3.4 Starting from paragraph [0099], the description as published refers to instability during operation when the device comprises a single element such as a single abrasive burr, and to the possibility of using counterweights at proximal and/or distal locations to increase stability (paragraphs [0101] and [0102]). Starting from paragraph [0103], configurations with a proximal and a distal counterweight are described, and paragraph [0107] then discloses that "there may be more than one proximal counterweight, and/or more than one distal counterweight". This provides a basis for the above feature, given that the device of claim 1 of the main request already comprises a proximal and a distal counterweight. Hence, the feature above is directly and unambiguously derivable from the application as published.

4. Remittal

4.1 The conclusion that the feature discussed above is disclosed in the application as published is not sufficient to determine whether or not the main request complies with Article 123(2) EPC. To do so, it is necessary to establish whether the patent application - including, in particular, the combination of features defined by claim 1 - contains subject-matter which extends beyond the content of the application as filed.

4.2 As mentioned in section 2. above, the examining division incorrectly relied on the claims filed on entry into the European phase for the assessment of Article 123(2) EPC. It therefore appears that a proper assessment of compliance with Article 123(2) EPC may not yet have been carried out.

4.3 Furthermore, it is not apparent from the first-instance proceedings whether the examining division could have had further concerns in relation to other requirements of the EPC, for example in relation to Article 52(1) or 84 EPC.

4.4 Consequently, the board considers that there are special reasons within the meaning of Article 11 RPBA to remit the case to the examining division for further prosecution.