Intellectual Property Enterprise Court

IP-2024-000024 - [2025] EWHC 492 (IPEC)

Fecha: 07-Mar-2025

Piercing stylus, obturator and trocar

Piercing stylus, obturator and trocar

94.

There was debate about the function of the piercing stylus in Wan as the skilled person would have perceived it to be.

95.

Mr Saeb-Parsy discussed what he said would have been seen by the skilled person as puzzles in his or her attempt to understand Wan. I will quote the relevant paragraph of his first report in full:

‘113. There are, however, a number of errors and points in the specification that the Skilled Urologist would find difficult to understand why they have been written in the way they have:

(a)

The most significant issue is the description of item 6 as a “stylus”. From the way that it is drawn in Figures 3 and 5, it appears to be a very large needle. I also understand from Clyde & Co that Well Lead considers that the correct translation of the Chinese words used for item 6 is “piercing needle”. However, the Skilled Urologist would be puzzled as to why a needle would be necessary. Paragraph [0004] says that an opening has already been made at the surgical site when the “stylus” is inserted. I take this to mean that the patient’s skin has been punctured. This suggests that Wan is contemplating the “stylus” being used as a needle to puncture a passageway into the organ being operated on (the kidney, gall bladder or bladder).

(b)

However, if item 6 is a needle, it is a very sizeable one that would only be suitable for puncturing in a straight line directly into a hollow organ making sure that there are no other structures or organs in its path that could be pierced or damaged by it. This would make even an experienced urologist very hesitant about using the device, especially in the kidney. In contrast to this, the PCNL procedure that is used in practice to get access to the kidney, involves making a small incision in the skin and passing a very small, fine needle into the kidney. A guidewire for a serial dilator or balloon dilator is then passed into the kidney. Once the urologist is happy the guidewire is in the kidney and the collecting system, the dilator is inserted following the guidewire and is used to serially dilate the hole in the kidney until it is large enough to be able to insert the access sheath (or sleeve tube as it is called in Wan). This is not, though, a procedure that the Skilled Urologist would carry out as it is a sub-specialist area of surgery (though the Skilled Urologist would be aware of it from their training).

(c)

For the reasons in (a) and (b), I had taken item 6 to be a form of “introducer” similar to an obturator for a UAS.

(d)

The procedures that Wan says its device can be used for are also somewhat puzzling. These are “percutaneous nephroscopic surgery, gall bladder-preserving surgery, and cystolithotrity in women” (paragraph [0001]). My understanding is that Wan’s device is essentially for percutaneous surgery only. As indicated above, by percutaneous nephroscopic surgery, I take Wan to mean PCNL. “Cystolithotrity” is incorrect terminology and should be “cystolithalopaxy” (the treatment of bladder stones normally via the urethra). I can see no reason why Wan says that this procedure is for women and not for men as well. The procedure is routinely used in the treatment of both men and women. But more importantly, the Skilled Urologist would not want to use a rigid (see below) access sheath with a large, sharp “stylus” in the urethra due to the risk of repeatedly puncturing the urethra’s walls.

(e)

In addition to the above points, “lithotrity” in paragraph [0003] should be “lithotripsy”.

(f)

Overall, these points and the way in which Wan is written generally suggest that it may have been drafted by a product engineer, who is not fully familiar with how urological procedures are carried out or the correct terminology to use for them rather than being written by a clinician or by a product engineer working in conjunction with a clinician.’

96.

Mr Saeb-Parsy explained his assumption in sub-paragraph (d) that the piercing sheath in Wan is rigid:

‘Wan does not say what materials its tubes are made of but the assumption from its specification is that they would be hard, rigid ones. This is partly from the need for Embodiment 1 to push the sleeve tube into the piercing tube during an operation (which would require rigidity of materials) and partly from the comment in paragraph [0011] on sterilisation. This is another passage that the Skilled Urologist would be puzzled by – there is no reason why having a control slit in the branch tube would assist in sterilisation – but the fact that Wan envisages its device undergoing sterilisation would suggest to the Skilled Urologist that is intended to be reusable and made of a robust material. Generally urological devices that are reusable are made of stainless steel.’

97.

This reading of Wan by Mr Saeb-Parsy was not disputed by Professor Somani save with regard to Mr Saeb-Parsy’s view that the piercing sheath would be taken by the skilled person to be rigid. Professor Somani had three reasons why it may not be: (i) embodiment 2 does not require the sleeve to be pushed into the piercing tube, (ii) flexible items can be sterilised and (iii) the reference to use in cystolithotrity (probably better: cystolithalopaxy) in women implies use of the sheath in the urethra.

98.

In his written evidence Mr Saeb-Parsy introduced the device known as a ‘trocar’, part of the CGK at the priority date:

‘A trocar was a device used to create a channel into a cavity such as the abdomen to allow passage of instruments such as a laparoscope into that cavity. A trocar typically consisted of three main components: a sharp-tipped obturator, a cannula, and a valve mechanism. The obturator was a rigid, pointed instrument used for the initial puncture of the abdominal wall or hollow organ.’

99.

Mr Saeb-Parsy stated that a better term for the stylus in Wan was a trocar. The reason for this was the similarity in appearance between the piercing stylus 6 shown in Wan and a trocar. This view seems to have developed only after Mr Saeb-Parsy was shown the Patent and asked about differences between Wan and the Patent. As appears from his paragraph 113, quoted above, before then he thought that, notwithstanding the use of the adjective ‘piercing’, the stylus is similar to an obturator for use in ureteroscopy.

100.

Mr Saeb-Parsy reinforced his revised view by stating that no urologist would insert a trocar into a kidney. He went further, saying that no urologist would consider using a trocar for any ureteral procedure because they are made of stiff material such as stainless steel rather than flexible material. The implication of this evidence is that the device disclosed in Wan is paradoxically unsuitable for any of the procedures which Wan states in paragraph [0001] to be the very procedures for which it is to be used: PCNL, gallbladder preserving surgery and cystolithalopaxy in women. Professor Somani agreed that a trocar would not be used for any such procedure.

101.

Mr Saeb-Parsy offered no explanation for the paradox he implied except to say that the skilled person would wonder whether the writer of Wan knew what they were talking about. That would assume that Dr Wan himself had had no input in the writing of Wan: in cross-examination Mr Saeb-Parsy stated that Dr Wan, also the inventor of the Patent, is a urologist who would know the steps of urological procedures.

102.

Professor Somani’s evidence was simpler. Mr Saeb-Parsy’s first impression was right: the skilled person would understand that the stylus in Wan is an obturator. He pointed out that Mr Saeb-Parsy’s stated reason for the change of heart, that the Wan stylus looks like a trocar in figure 3 of Wan, is unconvincing because it looks almost the same as the obturator shown in the figures of the Patent.

103.

Professor Somani went on give other reasons. First, trocars are typically used in keyhole surgery and Wan says nothing about that procedure. Secondly, trocars are never used in any of the procedures expressly identified in Wan as those for which its device is intended. Third, as Mr Saeb-Parsy said, no urologist would insert a trocar into a kidney. Fourth, as Mr Saeb-Parsy also said, the skilled person would believe that the sheath in Wan is an access sheath which uses suction to remove stones and fragments. Wan describes the use of the stylus: it is inserted into the sheath, both are introduced into the surgical site via a pre-cut opening, the stylus is withdrawn and replaced by an endoscope. This is fully consistent with how an obturator is used.