Resectoscope With Continuous Irrigation

Abstract

An improved resectoscope for transurethral resection of prostate and bladder tumors provides continuous irrigation of the operative field with clear fluid and continuous drainage of bloody fluid from the bladder. This is accomplished by means of an outflow conduit positioned above the telescope shaft, with its inlet located beyond the objective lens. There are several alternative structures and arrangements for the inlet of the outflow conduit. In one a baffle is provided for guiding and separating the inflowing clear fluid stream and the outflowing bloody fluid; in another an opening in the upper part of the beak of the resectoscope sheath to permit passage of the bloody fluid in the bladder to the outflow conduit inside the sheath; while in another there are two entrances to the outflow system, the first being through the opening in the beak of the sheath and the second in a baffle plate below the beak, the latter being effective only when the first is closed by surrounding tissue. The outflow conduit may be provided by space within a tube within the sheath within which tube the telescope shaft is housed, or it may be provided by the space between outer and inner walls of the sheath above a telescope shaft.

Description

BACKGROUND OF THE INVENTION

Endoscopic instruments, as widely used in urology, are introduced through the urethra into the bladder in order to visualize the operative field and permit the performance of various operative procedures, typical instruments being the resectoscope, urethra cystoscope, lithotriptor, lithotrite and biopsy endoscopic forcep. All of these instruments include an elongated hollow sheath which is itself introduced through the urethra.

A resectoscope is an endoscopic instrument for the transurethral resection of pathological tissues from the prostate and bladder without incision. In the use of known resectoscopes it is necessary to interrupt the procedure frequently to evacuate accumulated bloody fluid from the bladder, this being done to avoid the dangerous over-distension of the bladder by the introduction of clear fluid at high pressure in order to maintain clear vision.

A resectoscope of known and conventional construction is comprised of an arrangement of four principal, easily detachable elements, these being a sheath, a telescope, a cutting loop electrode and a working element. These parts are disclosed in FIGS. 1 and 2, which illustrates a resectoscope of the prior art as background for disclosure of the invention, and comprise the tubular sheath 2 which provides a passageway through the human urethra to the area of visual and operative interest, and which has a beak 3 at its distal end. At its proximate end the sheath has a socket base 4 at which there is a connection 6 for the introduction of irrigation fluid, such as sterile water, with a stop cock 8, and a thumb screw 10 for attaching the sheath to the working element when the instrument is assembled for performance of an operation.

The assembled resectoscope comprises the sheath and its enclosed parts and the working element and its parts. The parts within the sheath are the telescope holder tube 20 through which the telescope shaft and light conductor cables are passed, the cutting loop electrode 22, a tube 24 for holding the rigid stem of the cutting loop electrode leads 26, and an outflow conduit 28 which is provided in some resectoscope models for transmitting fluid from the clear inflow pathway to the proximate end of the sheath for removal through a connection 30 and stop cock 32.

The telescope comprises shaft 30, objective lens 32 at the distal end of the shaft, and an ocular lens (not shown) and eyepiece 34 at the proximal end, a light connection 38, and a light conductor inside the shaft, running from connection 38 to the distal end for providing illumination. The telescope shaft extends from the working element and is attached to it by suitable means.

The cutting loop electrode 22 comprises an approximately semi-circular cutting loop formed by a thin bare wire which is charged with high frequency electrical current and is used to resect pathological tissue and coagulate bleeding vessels, the two symmetrical lateral branches 26 which are electrically insultaed and connect the cutting loop to the rigid stem which transmits reciprocating movement of the working element to the cutting loop, and a bare metal end (not shown) for connection to the dielectric block 50 of the working element. High frequency electricity is supplied at connection 40 for energizing the cutting loop.

The telescope and the cutting loop electrode are assembled with the working element before they are introduced into the sheath. In surgical operations the procedure is as follows: first the sheath is passed through the urethra, and then the working element, with the telescope and the cutting loop electrode attached, is plugged into the sheath's socket base and firmly tightened. Thereafter, the working element and the electrode are the operative mechanism of the instrument.

The working element comprises a metal bridge formed by end metal bridge members 50 and 52 which are connected by one top bar 54 and two spaced parallel rods 56 which serve as runners for the reciprocating movement of the dielectric block 50, which movement is transmitted to the cutting loop. High frequency electric energy is supplied to the plug-in electric inlet 40 and by internal connections is transmitted to the cutting loop electrode.

The rotary thumb holder 60 is operated by the surgeon in order to move the block 50 forwardly of the instrument against the resilient return force of steel leaf spring 62.

Proper endoscopic visualization requires the presence of a clear fluid medium at the operative field between the objective lens of the telescope and the tissues being observed, and this is provided by the inflow of a clear fluid through the sheath which is delivered by gravity from an overhead reservoir and is controlled at the instrument's inlet 6 by stop cock 8. However, blood is produced by the resected tissues, making a turbid bloody medium at the operative field, and vision is made possible only by maintaining an inflow of clear fluid in front of the objective lens. Hydrostatic pressure is increased in the bladder by the continuous inflow of clear fluid which is accumulated in the bladder, but if the inflow rate of clear fluid is reduced the turbidity is often sufficient to impair vision, and at this point the surgeon must stop the operation and detach the working element from the sheath in order to empty the turbid bloody fluid from the bladder. This interruption of the surgical procedure must be performed frequently when presently known resectoscopes are used, and these periodic interruptions produce dangerous difficulties such as temporary loss of visual orientation, prolonged bleeding, extended operative time, and sometimes require further anesthesia. To avoid these difficulties some surgeons maintain a clear medium at the operating field by increasing the volume of the clear fluid inflow by raising the exterior reservoir, but this practice increases the intravesical hydrostatic pressure, overdistending the bladder and making possible dangerous complications such as perforation of the bladder, extravasation of fluid, and entrance of irrigating fluid into the circulation system of the body through open veins at resected tissues, which may produce hypervolemic and toxic syndromes which may be fatal.

An outflow conduit such as that shown at 28 in FIG. 1 is sometimes provided within the sheath and has its distal or inlet end spaced well inwardly of the distal end of the sheath, and at its proximate end is connected to discharge through the lateral outlet 30 having a stop cock 32. The distal end of such an outflow conduit is located in a plane disposed substantially inwardly of the distal end of the closed, or full-round, section of the sheath which is indicated by line B-B in FIG. 1, and between that plane and the inlet of the conventional outflow conduit 28, clear fluid flows toward the distal end of the sheath with a pressure greater than the pressure inside the bladder. Consequently, the turbid fluid inside the bladder can never reach the inlet of such an outflow conduit because it cannot pass through the described region within the sheath where there is the higher hydrostatic pressure of the clear fluid. Thus, part of the inflowing clear fluid in the sheath is drained through such an outflow conduit and never reaches the operative field in front of the lens, which is always located under the beak of the sheath. When such an outflow conduit is provided the net result is a reduction of the inflow rate, which has an adverse effect on the visibility in front of the lens, and the clear fluid which is drained before reaching the end of the sheath is entirely ineffective and is wasted. This explains why every time the stop cock of the outflow conduit is opened only a clear inflow fluid is drained, and is the reason why several modern resectoscopes have eliminated this outflow conduit.

SUMMARY OF THE INVENTION

The invention provides an endoscopic urological instrument with an outflow conduit having its distal, or inlet, end positioned in a plane at the distal side of the objective lens of the telescope, and having means for constantly providing a supply of clear irrigating fluid beneath the beak of the resectoscope, whereby clear vision of the operative field is constantly available.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view, partly in section, of a resectoscope according to the prior art;

FIG. 2 is a sectional view taken on line 2--2 of FIG. 1;

FIG. 3 is an enlarged view of the distal end of a resectoscope according to the invention;

FIG. 4 is a sectional view taken on line 4--4 of FIG. 3;

FIG. 5 is similar to FIG. 3 but shows a modified form of the invention;

FIG. 6 is a sectional view taken on line 6--6 of FIG. 5;

FIG. 7 is a view similar to FIG. 3 showing a modified form of the embodiment of the invention disclosed in FIG. 3;

FIG. 8 is a sectional view taken on line 8--8 of FIG. 7;

FIG. 9 is similar to FIG. 3 and shows a further embodiment of the invention;

FIG. 10 is a sectional view taken on line 10--10 of FIG. 9;

FIG. 11 is similar to FIG. 3 and shows a further embodiment of the invention;

FIG. 12 is a sectional view taken on line 12--12 of FIG. 11;

FIG. 13 is similar to FIG. 4 and shows a further modification of the form of the invention disclosed in FIGS. 9 to 11;

FIG. 14 is a sectional view taken on line 14--14 of FIG. 13;

FIG. 15 is a vertical sectional view through any of FIGS. 3, 5, 7, 9, 11 and 13 showing a modified sectional shape of the outflow conduit;

FIG. 16 is a side view, partly in section, of a urological endoscopic instrument having an outflow conduit according to the invention but of different construction than that disclosed in FIGS. 3 to 13, and

FIG. 17 is a sectional view taken on line 17--17 of FIG. 16.

DESCRIPTION OF THE INVENTION

A urological endoscopic instrument, such as a resectoscope, constructed in accordance with this invention comprises the same four separable but readily connectable elements of the conventional instrument described above, which are the sheath and telescope and, in the case of the resectoscope, the cutting loop electrode and working element. The telescope may be conventional, as the invention does not modify its structure but only its position within the sheath relative to other parts. The cutting loop electrode may comprise two smaller lateral stems instead of the larger one beneath the telescope because there the space is slightly reduced, but otherwise the cutting loop electrode is not modified by the invention.

Means are provided by the invention for facilitating and insuring the removal of turbid fluid from the operative field into and through the resectoscope in such a manner that the visual field of the telescope is not impaired by such fluid. Such means comprise, first, the provision of an outflow conduit above the telescope tube and having its distal end positioned on the distal side of the objective lens of the telescope. A first embodiment of such means is disclosed in FIGS. 3 and 4 and comprises an elongated tube 80 which is positioned within the sheath and extends longitudinally thereof and is smaller in cross section than the interior of the sheath, thus leaving a space 82 between the two which provides a conduit for the inflow of clear irrigating fluid to the operative field. The telescope shaft 30 is positioned within this tube and is smaller in cross section than the interior of the tube and is positioned at the lower part of the tube, leaving a space 84 above the telescope shaft and within the tube which functions as the outflow conduit for turbid fluid from the operative field. In further accordance with the invention, and as clearly shown in FIG. 3 the distal end of the tube 80 is positioned outwardly of the distal end of the closed section of the sheath, which end is denoted by the line B-B in FIGS. 1 and 6 and outwardly of the objective lens of the telescope.

The clear liquid used to irrigate the operative field is transmitted to the distal end of the sheath through the space within the sheath and outside the tube 80. This space is denoted 82 in the drawings and clear fluid is supplied to it through the tube connection 6 and stop cock 8 as described above.

It will be noted that distal of plane B-B the sheath opens under the beak and there is a drop in the hydrostatic pressure of the inflow fluid, which mixes in all directions with the fluid in the bladder. The operative field is under the beak and is where most of the heavy bleeding occurs, and therefore the whole inflow of clear fluid will mix there with the blood, and the mixture will be drained through the outflow conduit.

In FIGS. 5 and 6 there is illustrated another embodiment of the invention which further improves the efficiency of the outflow conduit in withdrawing turbid fluid, and in which the space 82 between the upper part of tube 80 and the upper half section of the sheath is blocked at the distal end of the tube 80 by a transverse buffer plate 90 which acts to separate the outflow and inflow streams, causing the inflowing stream of clear liquid in passage 82 to enter the area beneath the beak only at the lower part of the sheath. This arrangement prevents shortcircuiting of any part of the inflowing clear liquid within the sheath and outside of tube 80 into the outflow conduit in the space beneath the beak which is at low pressure because of the discharge thereof of the inflowing clear fluid. Although the system shown in FIGS. 3 and 4 is a major improvement over the prior art and is simple enough to be economically implemented, the further development described in this paragraph and illustrated in FIGS. 5 and 6 represents an added feature, increasing the efficiency of the removal of turbid fluid and better utilizing the clear fluid for washing the operative field.

In FIGS. 7 and 8 there is illustrated a modified form of the embodiment of the invention disclosed in FIGS. 5 and 6, in which the transverse buffer 92 at the distal end of tube 80 is inclined rearwardly of the sheath from its lower to its upper edge, thereby directing the inflowing stream of clear irrigating fluid downwardly and improving the separation of that stream and the outflowing turbid stream.

A further, and very important, modification of the embodiments of the invention disclosed in FIGS. 3 to 8 is disclosed in FIGS. 9 and 10 and provides a completely novel concept in the structure and operation of a urological endoscopic instrument such as a resectoscope. In this form of the invention an orifice 100 is provided in the upper wall of the beak of the sheath with its distal edge positioned inwardly of the distal end of the beak and its proximate edge positioned just outwardly, i.e., toward the end of the beak, from the objective lens 32 of the telescope tube.

Buffer means may, if desired, be provided in association with orifice 100, and such means are shown in FIGS. 11 and 12 and comprise a plate 100 which extends longitudinally of and within the tube 80 which encloses the telescope shaft and provides the outflow conduit, and is welded to this tube and extends outwardly toward the end of the beak of the sheath from the distal end of the tube. At that end of the tube and extending upwardly to the inner wall of the sheath the plate has a vertical flange 104 which, like the flange of FIGS. 5 to 8, blocks the inflow of clear irrigating fluid through the upper part of the sheath. The plate 102 is extended outwardly, i.e., toward the distal end of the sheath, from the flange 104, and this part of the plate underlies the orifice 100 and at its outer end is inclined upwardly toward the sheath as shown at 106.

The orifice 100 provides an entrance through the sheath and into the outflow conduit 84 for the turbid fluid in the bladder. All the clear irrigating fluid will flow along the path of the arrow A in FIG. 11 thereby washing the operative field in front of the objective lens 32 of the telescope and causing continuous clear vision of the operative field, and also washing the turbid fluid produced at the field toward the bladder so that this is constantly drained downwardly through the orifice 100 and outwardly through the upper part of the outflow tube 80. This is a highly efficient irrigation system, providing clear fluid to wash the operative field in front of the objective lens and continuously removing only turbid fluid from the bladder.

In FIGS. 13 and 14 there is disclosed a modified form of the embodiment illustrated in FIGS. 11 and 12, and in this modified form the upwardly and outwardly inclined flange 106 is provided with an aperture 108 which extends downwardly from its upper edge. This aperture provides, in combination with the sheath aperture 100, a double inlet for the outflow conduit 84. In spite of the fact that the orifice 100 is near the end of the sheath, it is out of the visual field and there is a remote possibility that tissue may shut it off without being noticed by the surgeon. It may also be closed during operations being performed within the urethra. The second aperture 108 prevents stopping of drainage under such extraordinary conditions, but in order to prevent a greater proportion of the drainage being taken through this alternative inlet it is made much smaller than the orifice 100 in the top of the sheath. Therefore, under normal conditions most of the drainage fluid will be taken through the inlet orifice 100.

While the tube 80 which encloses the telescope shaft 30 and also provides the outflow conduit may have the generally elliptical cross sectional shape shown in FIGS. 3 to 14, it may have different cross sectional shapes such as that disclosed in FIG. 15 in which it has a lower part 120 of part-circular shape which partially surrounds the telescope shaft 30 and an upper part 122 which is transversely enlarged and therefore provides an outflow conduit of greater volume and capacity than the elliptical tube 80.

The outflow conduit for the removal of turbid fluid may be provided by means other than the tube 80 which has been described and which serves also enclose the telescope tube. One such alternative means is disclosed in FIGS. 16 and 17 and comprises a sheath 140 having two spaced walls 142, 144 at its upper part which provide between them a crescent shaped passage 146 opening at the distal end of the sheath and providing an outflow conduit connected to discharge through connection 148 and stop cock 150. As in other embodiments of the invention the interior of the sheath provides a conduit for the inflow of clear liquid to the operative field from a connection 6 and stop cock 8. It will be seen that the inlet or distal end of the outflow conduit 146 is distal of the objective lens 32 of the telescope, and in all other respects the position, relative position, operation and functions of the outflow conduit 146 correspond to those of the tube 80 of the other embodiment of the invention.

Claims

I claim:

1. A urological endoscopic instrument, comprising an elongated cylindrical beaked sheath,

a tube within and extending longitudinally of the sheath with its distal end within the beak of the sheath, and being of less cross sectional area than the sheath to provide between the sheath and the tube an inflow conduit for irrigating fluid for the operative field,

means at the proximate end of the sheath for supplying irrigating fluid to the inflow conduit,

a telescope having a tubular shaft within and extending longitudinally of the tube and being of less cross sectional area than the tube to provide between the tube and the telescope shaft an outflow conduit for turbid fluid from the operative field,

an outflow connection at the proximate end of the tube for removal of turbid fluid from the outflow conduit,

the telescope having an objective lens at the distal end of the shaft which is proximate to the distal end of the tube.

2. An endoscopic instrument according to claim 1, comprising in addition, a buffer plate at the distal end of the tube positioned externally of the tube at the upper part thereof and closing the inflow conduit between the upper part of the sheath and the upper part of the tube.

3. An endoscopic instrument according to claim 2, in which the buffer plate is positioned normal to the axes of the tube and sheath.

4. An endoscopic instrument according to claim 2, comprising in addition a flange connected to the buffer plate and positioned distal thereto and being upwardly inclined to the axis of the tube and sheath from its lower edge to its upper edge.

5. An endoscopic instrument according to claim 4, in which the flange has an aperture therein at and adjacent its upper edge.

6. An endoscopic instrument according to claim 1, comprising in addition the provision of an opening in the upper wall of the beak of the sheath on the distal side of the objective lens of the telescope.

7. An endoscopic instrument according to claim 6, in which the proximate edge of the opening is on the distal side of the objective lens of the telescope.

8. An endoscopic instrument according to claim 6, in which the buffer plate is positioned beneath the proximate edge of the opening, and comprising in addition a flange within the sheath positioned beneath the distal part of the opening and having a vertical extent approximately equal to that of the buffer plate and being inclined forwardly of the sheath from its lower edge to its upper edge.

9. An endoscopic instrument according to claim 8, in which an aperture is provided by notching the edge of the flange.

10. A urological endoscopic instrument, comprising an elongated cylindrical sheath, means for supplying clear irrigating fluid to the interior of the sheath at the proximate end thereof for delivery to the distal end of the sheath to irrigate the operative field, the sheath having two spaced walls at the upper part thereof extending from end to end of the sheath providing an outflow conduit for removal of turbid fluid from the operative field.