US 3144020 A
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1964 F. G. ZINGALE 3,144,020
RESECTOSCOPE SHEATH Filed Aug. 9, 1960 L INVENTOR I FRANK azmcma ATTORNEY United States Patent 3,144,020 RESECTOSCOPE SHEATH Frank G. Zingale, 9762 Old Warson Road, St. Louis, Mo. Filed Aug. 9, 1960, Ser. No. 48,549 3 Claims. (Cl. 128-4) In general this invention relates to diagnostic and surgical instruments, and has particular use in resectoscopes and endoscopes.
The principal object of this invention is to provide a resectoscope sheath in which the portions of the instrument which touch the patient are made of an insulating but antihesive, slippery material.
Resectoscope sheaths have been made of Bakelite for thirty years because of its insulating properties, whereas obturators have been made of metal, stainless steel or chrome-plated brass being the materials of choice.
A further object of my invention is to provide a resectoscope sheath construction which may be subjected to autoclaving in order to sterilize the instrument.
A still further object of my invention is to provide a flexible sheath for the resectoscope and a flexible resilient tip portion on that sheath to facilitate passage through the tortuous constricted channel of the urethra.
Since the sheath of the resectoscope is used with an electrode for incising urethral strictures by means of high frequency currents, a further object of this invention is to make the sheath insusceptible to burning by the cutting loop. In the past Bakelite sheaths have been uniformly and consistently burnt at the tip by the action of the cutting loop. This results in a roughened end on the Bakelite sheaths. When they are withdrawn and upon subsequent insertions and withdrawals, these roughened tips cause injury to the patient in the form-of cuts and digs on the inside of the urethra. The cauterizing tip moves about one-fourth of an inch during the customary operation with respect to the resectoscope sheath. It is this movement of the almost red hot tip which produces jagged edges on the top of the rigid Bakelite sheaths.
An additional object of this invention is to provide a construction which electrically insulates the patient from the urologist.
These and other objects of my invention will be apparent to those skilled in the art from a study of the following specification and reference to the accompanying drawings in which:
FIGURE 1 is a side elevational view of a sheath and obturator embodying the features of this invention, shown in assembled condition preparatory to insertion through the urethra;
FIGURE 2 is a side view, in perspective of the obturating element of this invention, turned approximately 45 with respect to FIGURE 1 and with a portion of the obturator tip shown in section;
FIGURE 3 is an enlarged end view of the sheath when the obturator of FIGURE 2 has been removed; and
FIGURE 4 is an enlarged transverse section view of the stainless steel tube and Teflon tubing of the sheath.
The resectoscope sheath comprises a thin tube 1 of flexible Teflon surrounding a hollow, very thin stainless steel tube 2. The Teflon tube 1 is longer than the tube 2. The outermost covering 1 of the sheath is made of Teflon because this material is the slipperiest, antihesive, nonconducting material which can be subjected to the autoclave.
The inner stainless steel tube 2 terminates at the dotted line position 2' of FIGURE 1. Beyond that position the tip consists entirely of the flexible Teflon tubing 1.
The sheath portion of the resectoscope also consists of a Teflon shield 3 in the form of a truncated right-angle cone, mounted on a stainless steel hub 4. The hub 4 has a large size wing catch 5 mounted on it. The wing catch is rotatable on a pivot 6 that is attached to the hub 4, and a water inlet tube 7, also of stainless steel, is attached to the hub 4. The water inlet tube 7 is provided with a bore that comprises part of a water passage.
8 that communicates with the central hollow interior of the stainless steel tube, thus the passage 8 includes a hole drilled through the hub, the Teflon sheath and the stainless steel tube 2 aligned with the tube 7.
The obturator assembly, as shown in FIGURE 2, comprises a body 9, with a handle 10 mounted upon a rod 11. The rod 11 is slidably disposed in a hole in the body 9. Another rod 12 is connected to the body 9 and to an obturator tip 13, which is preferably made of Teflon. Both rods 11 and 12 are pivotally attached to the tip 13. This construction is well-known in the art and may be illustrated by reference to Patent Number 2,079,233, issued May 4, 1937.
The eifect of the tip construction with two pivots is that relative longitudinal displacement of the rod 11 with respect to the rod 12 causes the obturator tip to swing'in the customary manner, as shown in solid and dotted lines in FIGURE 1. A stop 14 is provided on the rod 11 to contact the body 9 and limit the sliding motion of the rod 11 in one direction. The handle 10 contacts the body 9 to limit the sliding motion of the rod 11 in the opposite direction.
The rod 12 lies within a groove longitudinally disposed in an enlarged section 15 of the rod 11. This groove keeps the rods 11 and 12 in generally parallel positions. The resectoscope sheath 1 is flexible enough to move from its vertical position in the drawing and to follow the swinging movement of the obturator tip 13 between the solid and dotted line positions of FIGURE 1.
' This flexibility of the forward end of the sheath is most important. It is accomplished by making the sheath covering of a Teflon tube thin enough to be flexible. Thus a minimum of injury is done to the urethral tissues by the introduction of the resectoscope. It will be noted from the drawing that the entire surface of the resectoscope which touches the urethra is made of Teflon. This is true of the sheath covering 1, and the obturator tip 13.
In use, the obturator illustrated in FIGURE 2 is in serted within the sheath to the position illustrated in FIGURE 1, and the resulting composite instrument is carefully introduced into the urethral passage. The movable tip 13 guides the sheath. When the sheath is in place, the obturator is withdrawn as is conventional, and as also is conventional, the operating end of a resectoscope is introduced through the passage in the sheath until the cauterizing tip of the resectoscope reaches the end of the sheath and occupies the position generally occupied theretofore by the obturator tip 13. Such an electrode or cauterizing tip becomes almost red hot during the operation but cannot injure the Teflon insulating covering at the tip where the electrode replaces the obturator tip. It must also be recognized that the Teflon has a soft, flexible edge, contrary to the conventional Bakelite construction which has a rigid edge. This flexible characteristic renders it nearly impossible to shatter or break any portions from the flexible tip or the body of the sheath in regular use of the sheath. Thus no injury in the operation or in subsequent operations can accrue to the patient. This has not been the case with the Bakelite constructions which are subject to shattering.
In general rubber constructions are not satisfactory in the operation of a cauterizing tip, nor are constructions of polyethylenes or other plastic materials of that type, with which I experimented. These materials cannot withstand the temperatures to which they are subjected in the operation of the cauterizing tip. Further- Patented Aug. 11, 1964 more they generate relatively high friction when they slide. It is highly desirable to have the lowest possible friction between the tissue walls on the inside of the urethra and the covering of the sheath, aswell as between the obturator tip and the tissue walls. It is here that Teflon proves its vast superiority, for rubbers tend to stick, and plastics have a dry feel that tends to grab the urethra walls. Making the sheath with a Teflon covering and tip enables the operator to introduce the instrument easily, and since the Teflon has a greasy feel to its surface, it slides quite easily along the inner surfaces of the urethra.
An additional advantage accruing from making the outer tube 1 of Teflon and from making it larger than is common practice is that the urethra of the patient cannot be burned by the cauterizing electrode. This is because the electrode is insulated from the patient by Teflon at all places except at the protruding tip of the cautery instrument. In FIGURE 3 it will be seen that the annular portion 1, made of Teflon lies between the hub 4, which is permanently mounted on the outer sur-' face of the Teflon tube 1, and the stainless steel tube 2. Thus the Teflon tube 1 provides insulation between the tube 2 and the hub 4.
It will be understood that although this device is called a resectoscope sheath, it is also adapted to be used in the other natural body openings, and the use of such name is not intended to in any way limit the scope of the invention. 7
Having described my invention, what I claim is:
' 1. In a resectoscope, a sheath having a front end that is open and flexible, and a removable obturating means insertable in the sheath with an obturating tip of Teflon projecting beyond the front end of the sheath tofacilitate introduction of the sheath through a restricted channel, said sheath comprising a thin-walled stainless steel tube, a covering of Teflon in'the form of a flexible thinwalled tubing, fixed to and covering the entire outer surface of said stainless steel tube and extending beyond the front end of. said tube, terminating in a flexible resilient tip, a metal hub on said sheath adjacent the back end opposite the front end and secured to the outer surface of the Teflon tubing, insulated from said stainless steel tube by the interposition of said flexible thin-walled Teflon tubing, and a Teflon shield on said sheath and 4 integral with said sheath, said hub being between the shield and the back end of the sheath.
2. A resectoscope sheathcomprising a hollow metal tube having first and second ends, a Teflon tube surrounding the steel tube and having first and second ends, the first end of the Teflon tube having a thin walled, flexible extension beyond the adjacent first end of the steel tube, the second end of the Teflon tube being substantially aligned with the second end of the steel tube, a Teflon shield mounted on the Teflon tube near but spaced fromthe second end of the Teflon tube, and a hub mounted on the Teflon tube between the second end thereof and the Teflon shield, an obturator removably received within the sheath, the obturator having operating rod means extending through the metal tube and the flexible Teflon tube extension, an obturator tip pivotally attached to the rod means and having a part projecting beyond the said extension, the obturator tip being made of Teflon.
3. A resectoscope sheath having a front end that is open and flexible, and a removable obturating means insertable in the sheath to facilitate introduction of the sheath through a restricted channel, said sheath comprising a thin-walled metal tube, a thin-walled Teflon tube covering the metal tube and extending beyond the front end of the metal tube, the part of the Teflon tube that extends beyond the front end of the metal tube being flexible, the obturating means having an obturating tip projecting beyond the flexible extension of the Teflon tube, a metal hub on the sheath adjacent the back end of the metal tube, a shield of insulating material on the sheath, the shield comprising a wall mounted on the Teflon tube and extending radially outward therefrom, the hub being between the shield and the back end of the sheath.
References Cited in the file of this patent UNITED STATES PATENTS Great Britain Mar. 3, 1891