Patent Application
20170189109
Embodiments of the invention relates to an electrosurgical apparatus and in particular to the non-contact coagulation of tissue using an ionisable gas such as argon.
Argon beam coagulators have been known for many years, and examples are given in U.S. Pat. Nos. 4,040,426, 5,720,745, 6,039,736 and 6,197,026. The first example is an end-effect instrument, in which the ionised gas exits through the end of the instrument, while the latter two examples are directed at side-effect instruments, in which the ionised gas exits the instrument though an aperture in the side of the instrument. Such instruments are often referred to as APC instruments (Argon Plasma Coagulation).
APC instruments are often used in endoluminal procedures in which the length of the instrument is many times its diameter. In such situations it is often difficult to manipulate the tip of the instrument precisely into position, as a movement instigated at the proximal end of the instrument has a large distance to travel before constituting a corresponding movement at the distal end of the instrument.
Embodiments of the invention attempt to provide an instrument which is more versatile than any of the instruments in the prior art, and accordingly some examples provide an electrosurgical apparatus for coagulating tissue, comprising a flexible elongated tube having a proximal end and a distal end, an elongate sheath into which the flexible tube is inserted, a conduit though which ionisable gas can be supplied to the distal end of the tube, the tube including one or more apertures in the tube such that the ionisable gas is capable of exiting the tube in the region of the distal end of the tube, at least one electrode for ionising the ionisable gas prior to the gas exiting the one or more apertures, an intermediate sleeve into which the flexible elongated tube is inserted, a tube handle attached to the proximal end of the flexible elongated tube, and means for preventing the flexible sleeve from rotating, such that actuation of the handle causes the flexible elongated tube to rotate within the intermediate sleeve.
The intermediate sleeve ensures that rotation or longitudinal movement of the proximal end of the elongate tube is translated into a corresponding movement of the distal end of the tube, without the application of excessive force. Accordingly, the intermediate sleeve is conveniently formed of a low friction material.
As mentioned previously, the length of the tube is often many times its diameter. Therefore, the intermediate sleeve conveniently has a length more than 10 times its diameter, preferably more than 50 times its diameter, typically more than 100 times its diameter, and conceivably more than 500 times its diameter. According to one convenient arrangement, the intermediate sleeve extends the majority of the length of the elongated tube. Preferably, the intermediate sleeve extends to the distal end of the elongate tube with the exception of a distal end portion, the distal end portion containing the one or more apertures. In this way, the elongate tube is in contact with the intermediate sleeve along the majority if not the near entirety of its length. This provides an easier environment for movement of the tube as opposed to it being in contact with the bore of an endoscope, as would be the case in prior art instruments.
Preferably, one or both of the intermediate sleeve and the elongated tube is provided with friction reducing features. The friction reducing features are conveniently a plurality of projections, typically elongate projections. The friction reducing features are preferably present on the intermediate sleeve, although they can of course alternatively be provided on the tube itself. Typical projections are continuous raised ridges, so as to provide a smaller area of contact between the tube and the sleeve, hence reducing the frictional drag therebetween. The projections are conceivably longitudinal, helical, or intermittent, and can be of any cross-section effective to provide a low friction contact between the tube and the sleeve.
The means for preventing the intermediate sleeve from rotating conveniently comprises a sleeve handle capable of being held to prevent rotation of the intermediate sleeve. Thus the user of the APC instrument moves the elongate tube using the tube handle, while holding the sleeve handle in order to maintain the sleeve stationary.
The intermediate sleeve is conveniently formed of PTFE. Conceivably, the PTFE sleeve has a wire embedded therein, typically wound in a helix within the PTFE material of the sleeve, or alternatively in the form of a braid embedded within the PTFE material of the sleeve. The wire serves to stiffen the sleeve to prevent it from becoming twisted as the tube is rotated. Conceivably, the wire can have a dual purpose, being used to create the projections forming the friction reducing features as described previously.
Embodiments of the invention will now be further described, by way of example only, with reference to the accompanying drawings, in which:
Referring to
A tube handle 17 is connected to the proximal end of the tube 6 as shown in
Finally,
Those skilled in the art will appreciate that other constructions can be envisaged without departing from the scope of the present invention. For example, the number, location and shape of the apertures can be varied, as can the shape of the electrode element. Monopolar or bipolar versions of the instrument are possible, depending on the intended use, and different versions of the system can be envisaged for different endoscopic procedures.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1600202.4 | Jan 2016 | GB | national |
