GB2307644A - Resectoscope - Google Patents

Description

RESECTOSCOPE The present invention relates to a resectoscope. More specifically, it relates to a resectoscope having a tube with an oval cross section into which a working insert with tubes may be inserted, of which one tube forms a first lumen for an optic and another tube forms a second lumen terminating before the distal end of the shank tube and into which an electrode may be inserted from the distal side.

The electrode may be connected proximally with a HFconnection being axially adjustable in the second lumen and carrying a loop at the distal end, the shape of the loop being adapted to the inner contour of the shank tube.

Such designed resectoscopes are known from the practical state of the art, the channel accommodating the optic and the electrode being arranged symmetrically to the long transverse axis of the high oval shank tube. With this, the mutual arrangement is effected from the point of view of the cutting loop located at the electrode having a shape which allows a large as possible cutting width with the aim of reducing the operation time and easing the burden on the patient. In this respect an optimization is limited in that, in the shank tube having a given circumference, only a cutting loop of a certain shaping and length may be accommodated, whereby given as large a length as possible, the effective lower part of the cutting loop directly follows the inner circumferential curvature of the shank tube. With an oval shank tube and an arrangement of the cutting loop symmetrical to the long transverse axis this means that the cutting loop has a curvature in its effective region, of which the radius is smaller than that with a shank tube of the same circumference but having a round cross section. Although the design allows a high cutting depth, the cutting width is insufficient, which is of a particular disadvantage with prostate resection or removal of a myoma, since because of the narrower cutting width more raised parts are left, the smoothing of which requires a correspondingly longer operation time.

But now it has been found that, in accordance with the invention, these ratios may be improved when the cutting loop is arranged symmetrically to a plane defined by the longitudinal axis and the short transverse axis of the shank tube and is designed as a flat oval.

The advantages which may be achieved therewith lie particularly in that with the resectoscope designed according to the invention, in comparison to a conventionally designed resectoscope having a shank of the same circumference, the cutting loop may be significantly lengthened and at the same time the loop shape may be formed flatter in its active region, so that a larger cutting width may be achieved, which alone results in less time required for smoothing.

According to one advantageous design of the resectoscope according to the invention, the tube accommodating the optic and the tube accommodating the electrode may be rigidly connected to one another with an alignment to one another parallel to the axis, so that there results a deflection resistant unit.

The resectoscope according to the invention is hereinafter described in more detail by way of example with reference to the accompanying drawings, in which: Fig. 1 shows a lateral view of the resectoscope, comprising a shank, working insert, electrode and optic; Fig. 2 shows a lateral view of the shank; Fig. 3 shows a lateral view of the working insert; Fig. 4 shows a lateral view of the electrode, Fig. 5 shows a lateral view of the optic; Fiq. 6 shows an enlarged front view of the distal end of the resectoscope with a mounted electrode; and Fig. 7 shows an enlarged cross section through the resectoscope taken along the section line VII-VII in Fig. 1.

Referring to the Figures, the resectoscope according to one embodiment of the invention comprises three functional units, namely a shank 1, a working insert 2 with an electrode, and an optic 3. The working insert 2 is inserted into the lumen 4 of the shank 1 from the proximal end and can be connected to the shank in the inserted condition by way of a conical receiver. The working insert further accommodates the optic 3, which for its part can be connected to the proximal end of the working insert 2 using a straining ring 21.

As can be deduced from Figures 6 and 7, the shank 1 is composed of a shank tube 7 with an oval cross section which is defined by a short transverse axis 7a and a long transverse axis 7b. The shank tube 7 further comprises a longitudinal axis 7c and is provided at its distal end with an end piece 8 indicated in Fig. 2. At the proximal side the shank 1 comprises a coupling housing 9 with a toggletype fastener 10 and a tube connection 11.

The working insert 2 has a shank 12 which is composed of two tubes 13 and 14 which are parallel to one another and are unreleasably connected to one another such that their cross-sections together form the shape of a number eight.

With this, each of the tubes 13 and 14 enclose a lumen 15 and 16. At the proximal side, the shank 12 comprises a locking cone 17 which,after introducing the working insert 2 into the shank tube 7 of the shank 1, can be releasably attached to the toggle type fastener of the shank. With this the tube 13 is guided through the locking cone 17 and accommodates a locking body 18 which is guided axially displaceable on the tube 13 and is provided with a first handle part 19 as well as a HF-connection 20. The straining ring 21 and a second handle part 22 formed as a thumb ring 23 are arranged rotationally movable at the proximal end of the tube 13.

From the distal side the electrode 24 may be pushed into the lumen 16 of the tube, said electrode being formed at the distal end as a fork 25 with two fork legs 25a, at the distal end of which a cutting loop 26 is fastened. On the proximal side, the fork 25 is conductingly connected to a stem 27, of which the proximal end 28, after the complete insertion of the electrode 24 into the locking body 18, is inserted and detachably fastened in said locking body by way of a spring tensioned locking element 29, whereby an electrical contact between the stem 27 and the HF-connection 20 of the locking body 18 is effected. The fork legs 25a as well as the stem are formed insulated.

The optic 3 comprises a shank tube 30 which is insertable into the lumen 15 of the tube 13, this tube serving as the accommodation of the optical system and a fibre optic, and being provided at its distal end with an ocular 31 and a fibre optic cable connection 32. In the inserted condition, the optic 3 can be detachably fastened to the proximal end of the working insert 2 by way of the straining ring 21.

Due to the coupling of the electrode 24 to the locking body 18, by moving both handle parts 19 and 22 towards one another or away from one another, the electrode may be axially displaced with its stem 27 in the tube 14 and with the cutting loop 26 in the distal end of the shank tube 7.

With this, with a position in which both handle parts 19 and 22 are in the closest position to one another, the cutting loop 26 is pulled back into the end piece 8, whereby the design of the end piece as an insulating element prevents a flow of current from the cutting loop 26 to the shank tube 7. In order at the same time to centrally guide the cutting loop 26 in the shank tube 7, lateral inner webs, not shown, may be arranged at the height of the distal end region of the tube 14 which accommodates the stem 27 of the electrode 24.

As can be deduced from Fig. 7, with the resectoscope formed according to the invention, a cutting loop 26 may be applied which in comparison to the usual roughly semicircular formed cutting loop 26a, has a larger circumference and thus an increased cutting performance.

Furthermore the cutting loop 26 has a flat loop radius 26 in the active region, so that by these means also a significant reduction of the operating time can be achieved, since less applications are required for smoothing the cutting surface.

Furthermore tissues may be vaporized to a good effect with such loops.

Claims (3)

1. CLAIMS 1. A resectoscope comprising a shank having a shank tube with an oval cross section into which a working insert with tubes may be inserted, one tube forming a first lumen for an optic and another tube forming a second lumen terminating before the distal end of the shank tube and into which an electrode may be introduced from the distal side, said electrode being connectable proximally with a HF-connection, being axially adjustable in the second lumen and carrying a loop at the distal end, the shape of said loop being adapted to the inner contour of said shank tube, wherein the loop is arranged symmetrically with respect to a plane defined by the longitudinal axis and the short transverse axis of the shank tube and is designed as a flat oval.
2. 2. A resectoscope according to claim 1, wherein the tube accommodating the optic and the tube accommodating the electrode are aligned to one another parallel to the axis and are rigidly connected to one another.
3. 3. A resectoscope substantially as herein described with reference to the accompanying drawings.