IMPROVED ENDOMETRIAL CYTOLOGIC SAMPLING APPARATUS AND METHOD
BACKGROUND OF THE INVENTION
Technical Field
The present invention relates to methods and apparatus for collecting and examining sample tissue from an endometrial cavity. More particularly, the invention relates to improved endometrial cytologic techniques which simplify accurate diagnosis of endometrial cancer.
Discussion of the Prior Art
Until relatively recently, the incidence of cervial cancer was far greater than the incidence of endometrial cancer. This situation was reversed by the wide use of the PAP test to diagnose cervical carcinoma in a reliable manner. However, no such simple test presently exists for diagnosing carcinoma beyond the cervical os, namely, in the uterine endo etrium. The PAP test, apart from being reliable, is inexpensive and painless and relatively few patients are hesitant to periodically submit to such tests. Consequently, cervical cancer is generally diagnosed sufficiently early to permit effective treatment, thereby significantly reducing the incidence of cervical cancer relative to endometrial cancer.
Reliable cytologic sampling of the endometrial ■ cavity is required in order to provide reliable diagnosis of endometrial cancer. The sampling device must be sufficiently small to be inserted through the cervical opening, but must have a probe which includes a surface large enough to reliably contact and scrape cell samples from the wall of the endometrial cavity. This relatively
large probe must not only be insertable into the cavity, but must also be withdrawn without destroying the sample and without causing pain to the patient.
There are a number of prior art devices which attempt to solve the problem of reliable diagnosis of endometrial cancer. Examples of such devices may be found in U.S. Patent No. 4,227,537 (Suciu, et al.) and U.S. Patent No. 4,245,653 (Weaver). These devices include probes having brushes or other bristled members at their distal ends which may be retracted into an insertion sheath whereby the bristles are compressed to reside within the sheath. The sheath, with the brush or bristles retracted therein, is guided through the cervical opening into the endometrial cavity at which time the brush is projected out from the distal end of the sheath. The brush may then be rotated so as to contact the walls of the endometrial cavity and thereby collect cytologic samples. In order to withdraw the collected samples from the endometrial cavity, the brush is retracted into the sheath which is then removed from the vaginal canal. After such removal, the brush is once again projected from the sheath so that the collected samples may be smeared or otherwise transferred to a microscopic slide for examination.
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The technique as described above suffers from the disadvantage of requiring transfer of the collected sample to a microscopic slide. In the usual case, only a relatively small portion of the collected sample is actually transferred, thereby significantly reducing the reliability of the test for cancer cells. Moreover, the degree to which the bristles of the sampling device can be compressed or bent while withdrawn into the sheath without damage to the bristles severely limits the length or radial expanse of the bristles, thereby limiting the size of adequacy of the sample. This requires considerable manipulation of the probe when the brush has been projected out from the sheath in the endometrial cavity. This manipulation can cause considerable discomfort to the patient, thereby resulting in far less acceptance and willingness to submit to regular tests of this kind.
OBJECTS AND SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a method and apparatus for collecting and examining endometrial cytologic samples which causes
relatively little discomfort to the patient while providing reliable transfer of the sampled cells to the examining microscope.
It is another object of the present invention to provide a method and apparatus for collecting and examining endometrial cytologic samples which eliminates the need for transferring collected cytologic samples from the sampling device to a microscopic slide.
A further object of the present invention is to provide a method and apparatus for collecting and examining endometrial cytologic samples wherein a probe inserted into the endometrial cavity requires little or no manipulation to collect samples from the cavity wall.
A still further object of the present invention is to provide an endometrial cytologic sampling probe which easily enters the cervical opening and yet, is radially expandable to a greater distance than was heretofore possible with prior art probes.
In accordance with the present invention a transparent terminal membrane is employed as a sampling device at the distal end of a probe. The membrane is
expandable when the probe is projected from its sheath so as to readily contact the endometrial walls without undue manipulation of the probe. Upon contraction of the membrane and the removal of the probe, the membrane itself can be placed on a microscopic slide because of its transparency, thereby eliminating the unreliability involved in the step of transferring the collected samples from the probe to the slide.
In a preferred embodiment, the transparent membrane takes the form of a balloon-like member which, in its collapsed state, conforms to the tip and distal end section of the tubular probe. One or more holes are defined in the distal end section of the probe so that air or other fluid under pressure can be introduced into the probe to selectively inflate the ' balloon-like member. When inflated, the balloon-like member need only contact the endometrial surface in order to gather cytologic samples on the exterior of the transparent membrane. Vigorous manipulation of the probe is thereby avoided as is the discomfort to the patient which results from such manipulation.
Although the preferred embodiment involves an inflatable or balloon-like transparent membrane, the
essential feature is the transparent membrane, irrespective of how it is expanded once it is inserted into the endometrial cavity. Therefore, the invention encompasses within its scope any expandable configuration for a transparent membrane probe which permits the membrane to be selectively expanded and contracted so as to be temporarily stored in and projected radially outward from a sleeve or guide member.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects, features and many of the attendant advantages of the invention will be better understood upon a reading of the following detailed description when considered in connection with the accompanying drawings wherein like parts in each of the several figures are identified by the same reference numerals and wherein:
Figure 1 is a view in plan of an endometrial cytologic sampling assembly constructed in accordance with the present invention, showing the assembly prior to deployment of its sampling membrane;
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Figure 2 is a view similar to Figure 1 showing the assembly with the sampling membrane deployed;
Figure 3 is a view in plan of the core probe member of the assembly of Figures 1 and 2;
Figure 4 is a view in plan of the introducer sleeve member of the assembly in Figures 1 and 2;
Figure 5 is a view in plan of the body casing member of the assembly of Figures 1 and 2;
Figure 6 is a detailed illustration in partial section of the tip of the assembly of Figures 1 and 2, showing the tip prior to deployment in an endometrial cavity;
Figure 7 is a diagrammatic illustration in perspective showing the sampling membrane of the assembly of Figures 1 and 2 removed from the assembly and placed on a microscopic slide for examination.
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DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring more specifically to Figures 1 - 7 of the accompanying drawings, a core probe member 10 is elongated and tubular and has a Luer female fitting 11 secured to its proximal end. The distal end 13 of the core probe member 10 is closed and somewhat bulbous relative to the outer diameter of the core probe member throughout its length. In a typical embodiment, the core probe member 10 is 29.3 centimeters long, has an outer diameter of 0.02 inches and an inner diameter of 0.008 inches. These dimensions, of course, are merely representative of a typical embodiment, as are other dimensions set forth hereinbelow, and should not be construed as representing a limitaion on the scope of the present invention. The important aspect of the dimensions set forth herein relates to the necessity of inserting the core probe member 10 and the introducer sleeve, as described below, into the endometrial cavity.
A plurality of inflation port openings 15 are' defined through the wall of the tubular portion of core probe member 10 at locations which are within approximately 1.8 centimeters of the distal end 13. A
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balloon sleeve member 17 is disposed in a tight fit concentric relation about the core probe member 10 with the forward-most end of the sleeve disposed approximately 1.8 centimeters from the distal end 13 of the core probe member. The sleeve member 17 is approximately 0.250 inches in length and can be engaged about the core probe member by means of adhesive, a friction fit, or the like.
The core probe member 10 is disposed for longitudinal movement within an introducer sleeve 19 which takes the form of a tubular member which is shorter than the core probe member 10 by approximately 2.0 centimeters, not including the Luer fitting 11 as part of the core probe member length. The introducer sleeve 19, in a typical embodiment, has an outer diameter of 0.063 inches and an inner diameter of 0.039 inches. The inner diameter of the introducer sleeve is larger than the outer diameter of the balloon sleeve member 17 but is not larger than the diameter of the bulbous distal end 13 of core prove- member 10. Thus, the bulbous end 13 of the core probe member serves as a stop for limiting retraction of the distal end of core probe member 10 into the introducer sleeve 19, as illustrated in Figure 6. When the core probe member is so retracted in its undeployed position, the proximal end of the core probe
member extends approximately 1.8 centimeters out from the proximal end of the introducer sleeve 19. A series of longitudinally-spaced markings 20 extend from the distal end of introducer sleeve 19 along a portion of the length of the introducer sleeve. Markings 20 are equally spaced and preferably take the form of colored bands which serve as a gauge for the insertion steps of the unit in the vaginal tract and endometrial cavity. In a typical embodiment, these markings 20 are 5 millimeters apart.
A body casing 21 includes an intermediate tubular portion 22, a tapered distal portion 23 and a radially enlarged proximal portion 24. The tapered portion 23 of the body casing has a plurality of longitudinally spaced markings 25 appearing thereon, which markings are spaced by the same distance as the spacing between the series of markings 20 on the introducer sleeve 19. The introducer sleeve is secured within the body casing by means of welding, or the like, to prevent against relative longitudinal motion between the body casing and introducer sleeve. When the introducer sleeve and body casing are thusly secured, the markings 20 and 25 provide an uninterrupted scale of equally spaced distance markers which permit the physician to monitor the insertion depth of the instrument.
The radially enlarged proximal end 24 of body casing 21 is large enough to receive the Luer fitting 11 therein. The tapered distal end 23 of the body casings must be small enough at its outer diameter to permit it to be inserted into the vaginal canal of the patient.
Luer fitting 11 is adapted to be connected to a mating Luer lock fitting 27 disposed at the outlet end of a syringe 29. The syringe has a selectively actuable plunger 30 which permits delivery of pressurized air through the fittings 27 and 11 into the core probe member 10. Initially, however, during insertion of the unit into a patient's endometrial cavity, the syringe is disconnected from the core probe member.
An inflatable balloon member 31 is secured about the distal end of core probe member 10 and extends to within the spacing between balloon sleeve member 17 and the exterior of the core probe member. The open end of the balloon member 31 is thus sealed between sleeve 17 and core probe member 10. When the balloon member 31 is uninflated, it conforms precisely to the contour of bulbous distal end 13 and the section of core probe 10 between sleeve 17 and distal end 13. An important feature of the present invention is that the balloon
member is made of a transparent membrane material which can be selectively and safely inflated by pressurized air delivered by syringe 29 to the interior of core probe member 10 and out through inflation ports 15. The membrane-like thickness of balloon member 31 requires certain considerations in the construction of the unit, such as a smooth contour at the distal end 33 of introducer sleeve 19 where the bulbous tip 13 abuts in the retracted position of core probe member 10. In a typical embodiment, the balloon member 31 is made of a latex membrane. It must be readily inflatable to a radial expansion which permits the periphery of balloon member 31 to contact the walls of the endometrial cavity.
In operation, the instrument of the present invention is initially deployed in the retracted position of core member 10 as illustrated in Figure 6. Syringe 29 is not yet connected to the Luer fitting 11 which extends outwardly from the widened proximal section 24 of body casing 21. The physician places a speculum in the vaginal tract and visualizes the uterine cervical os. The instrument is then grasped by body casing 21 and, taking advantage of the flexibility and suppleness of the introducer sleeve 19 and its interior core probe member 10, introduces the instrument through the vaginal tract
and into the os. In the typical adult female patient, approximately 11 centimeters of the distal end of the instrument can be advanced within the endometrial cavity until resistance is felt, indicating that the probe has reached the endometrial vault. The markings 20, 25 designate the distance from the cervical os to the vault of the endometrial cavity and serve as an additional guide for the physician in determing the proper length of probe insertion.
After the endometrial cavity vault is contacted, or after it is otherwise determined that the probe can be advanced no further, the physician withdraws the entire probe approximately 3.75 centimeters as measured by the markings 20, 25. Core probe member 10 is then pushed longitudinally through the introducer sleeve from its proximal end at Luer fitting 11 until the Luer fitting contacts the proximal end of the introducer sleeve. This distance is approximately 1.8 centimeters and places the distal end 13 of the core probe member substantially centrally, in a longitudinal sense, within the endometrial cavity. The syringe 29 may then be connected to the core probe member 10 by means of fittings 11 and 27 and a volume of air is injected into the core probe member 10. Typically, 2 cubic centimeters of air would
be so injected into the core probe member. This injected air inflates balloon member 31 so that it expands into contact with the walls of the endometrial cavity. The syringe may then rotate about its axis, causing the core probe member 10 and balloon member 31 to rotate. The balloon member 31, which is in contact with the walls of the endometrial cavity, gathers cytological samples on its outer surface. The syringe plunger 10 may then be retracted to collapse balloon member 31. Preferably, although not necessarily, the core probe member is retracted within the introducer sleeve 19 before the instrument is withdrawn from the patient so that the balloon member 31 is protected within the sleeves. After the instrument has been withdrawn from the patient, the core probe 10 is extended from the distal end of sleeve 19 so that the balloon-covered portion of the core probe is accessible. The balloon is then cut from the core probe and placed on a microscope slide 35, as illustrated in Figure 8, to permit cytologic staining and examination of the gathered cytological samples by microscope 37. A crucial feature of the present invention resides in the fact that the membrane-like balloon member 31 is transparent so that the cytological samples do not have to be transferred from the balloon member to the slide for examination; rather, the examination takes place with the gathered samples still on the balloon member.
The particular dimension of 1.8 centimeters described hereinabove for the extension of the core probe member 10 beyond the distal end of the introducer sleeve 19 is thought to be optimum for the normal dimensions of the endometrial cavity in an adult female. However, variations from this dimension can certainly be employed within the scope and spirit of the present invention. Likewise, as noted above, other dimensions described hereinabove are by way of example only and are not to be considered limiting on the scope of the present invention» The important feature of the invention is that the instrument is sufficiently small so as to be painlessly inserted into the endometrial cavity. It is after insertion that the sample gathering member, mainly, balloon member 31, is inflated to a radial dimension which is greater than the cervical opening. In addition, the balloon member 31 is deflated before withdrawal of the probe so that discomfort is once again avoided. Since the unit is intended to be disposable after one use, cutting of the balloon member 31 after sampling may simply be with a knife or other suitable instrument, alternatively, a tool may be designed specifically for the purpose of removing the balloon from the core probe member.
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The use of an inflatable balloon is only one mechanism whereby a transparent sample gathering member can be inserted into the endometrial cavity, expanded for the purpose of gathering cell samples, and collapsed to permit withdrawal of the instrument without discomfort. Other techniques for inserting a transparent sample gathering member are intended to fall within the scope of the present invention. For example, an umbrella-like configuration may be employed wherein the transparent membrane takes the form of material interconnecting umbrella-like ribs which can be retracted into a sleeve such as the introducer sleeve 19 and automatically projects radially outward when extended longitudinally beyond the distal end of the sleeve. The important feature is the use of a transparent sample-gathering element which can be placed directly on a microscope slide for examining the gathered sample so as to avoid transfer of the sample to the slide or other support mechanism.
Having described several embodiments of a new and improved endometrial cytological sampling device constructed in accordance with the present invention, it is believed that other modifications, variations and changes will be suggested to those skilled in the art in
view of the description and illustrations presented herein. It is therefore to be understood that all such variations, modifications and changes are believed to fall within the scope of the present invention as defined by the appended claims.