Patent Publication Number: US-2007106174-A1

Title: Intrauterine anesthetic applicator and cell collection device and method of use

Description:
FIELD OF THE INVENTION  
      The present invention relates to apparatus and methods for anesthetizing the uterus and collecting intrauterine cells for diagnostic purposes. More particularly, the present invention relates to the application of anesthetic and removal of a uterine tissue sample while reducing a patient&#39;s discomfort.  
     BACKGROUND OF THE INVENTION  
      Various gynecological procedures require an analysis of intrauterine tissue. Previously-known devices typically have not been concerned with patient comfort as a design priority and may cause patient pain or discomfort during use. In addition, previously-known cell collection systems have required multiple devices to be inserted serially into the uterus to obtain a sample.  
      Intrauterine tissue collection apparatus and methods are known in which anesthetic is applied to the external cervical os using an elongated tube having a hard plastic acorn disposed at the distal end. The tube is inserted such that the acorn contacts the cervical os, and the anesthetic is then released. The acorn generally keeps the anesthetic localized at the application site, but some leakage may occur after the acorn is withdrawn. This leakage reduces the available anesthetic at the application site and thus the duration and intensity of the pain relief.  
      In addition, some patients are reluctant to undergo gynecological procedures due to the discomfort involved. For example, in U.S. Pat. No. 6,423,038 to Vancaillie, an intrauterine anesthesia device is described which is used to administer anesthetic and is then withdrawn to allow access for the next instrument used in the intra-uterine manipulation. To reduce patient discomfort, it would be desirable to provide apparatus device and methods that reduce the number of instruments that must be separately inserted into the patient.  
      Another source of discomfort associated with previously-known devices may arise due to the size of the device that must be inserted into the patient&#39;s vagina. For example, U.S. Pat. No. 5,231,992 to Leon describes a cervical cell collection device having a diameter of 40 to 52 mm. That device may by inserted and remain in the patient&#39;s cavity for 24 hours. To reduce a patient&#39;s discomfort, it would be desirable to provide a cell collection device with a reduced size compared to such previously known devices.  
      A further disadvantage of previously known apparatus is the amount of tissue removed during the cell collection process. U.S. Pat. No. 5,713,369 to Tao et al. describes a brush having a multiplicity of bristles designed to comprehensively contact the undilated uterine canal. It would therefore be desirable to provide apparatus and methods that reduce the degree of patient discomfort when obtaining a medically useful sample size.  
     SUMMARY OF THE INVENTION  
      In light of the foregoing, it is an object of the present invention to provide apparatus and methods for use in applying anesthetic and collecting intrauterine cell samples that facilitates anesthetic delivery and reduces leakage during the cell collection process.  
      It is also an object of this invention to provide apparatus and methods for applying an anesthetic and collecting uterine cell samples that reduces the number of instruments that must be serially inserted and removed from the patient&#39;s cavity.  
      It is a further object of the present invention to provide apparatus and methods for applying anesthetic and collecting uterine cell samples that employs a compact device profile to reduce patient discomfort.  
      Another object of the present invention is to provide apparatus and methods for applying anesthetic and collecting uterine cell samples that uses suction to collect cells from a focal sample area.  
      These and other objects of the present invention are accomplished by providing apparatus comprising an elongated outer tube having an applicator mounted on the distal end for delivering anesthetic, and a cell collection tube configured to be advanced through the elongated outer tube. The apparatus of the present invention has a compact insertion profile that minimizes discomfort, and facilitates the routine use of anesthetic in connection with intrauterine sample collection. In addition, the device is configured to enable cell collection without serially insertion of multiple devices.  
      In the first preferred embodiment, the elongated outer tube comprises a polymer or other non-metallic material having a length of approximately 20 cm to 30 cm long and a diameter of 3 mm to 5 mm. The outer tube includes a lumen that is open at the distal end and fitted with a standard Luer-Lok adapter at the proximal end to permit coupling to a conventional syringe. An applicator, preferably conical and comprising a closed-cell foam rubber, is disposed on the distal end of the elongated outer tube.  
      The apparatus further comprises an inner tube, preferably is at least 5 cm to 10 cm longer than the outer tube, configured to freely reciprocate through the lumen of the outer tube. The inner tube has proximal and distal ends and a lumen extending therebetween. The lumen is closed at the distal end but includes an aperture disposed in a lateral wall surface that communicates with the collection lumen.  
      A plunger is disposed in sliding relation within the inner tube. The plunger includes a distal end having the size and shape approximating the interior dimensions of the inner tube, so that proximal displacement of the plunger causes intrauterine fluid and cells to be drawn through the aperture and into the collection lumen.  
      In an alternative embodiment, the plunger is omitted and the inner tube instead has a Luer-Lok fitting at its proximal end. This fitting permits a conventional syringe to be attached to the proximal end of the inner tube so that the collection lumen may be used to dispense anesthetic into the uterus and subsequently permit uterine fluids and cells to be aspirated through the collection lumen.  
      Methods of using the apparatus of the present invention to anesthetize a patient&#39;s uterus and to collect cell samples also are provided. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The above and other objects and advantages of the present invention will be apparent upon consideration of the following detailed description, taken in conjunction with the accompanying drawings, in which like reference numerals refer to like parts throughout, and in which:  
       FIG. 1  is a side view depicting an exemplary embodiment of the apparatus of the present invention;  
       FIG. 2  is a side view of the individual components of the apparatus of  FIG. 1 ;  
       FIG. 3  is a schematic view depicting a method of using the apparatus of  FIGS. 1 and 2 ;  
       FIG. 4  is a side view depicting an alternative embodiment of the apparatus of the present invention; and  
       FIG. 5  is a side view depicting the individual components of the apparatus of  FIG. 4 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      The present invention is directed to apparatus and methods for applying anesthetic and collecting intrauterine tissue samples, while reducing patient discomfort. Previously-known intrauterine cell collection apparatus have focused primarily on efficient mechanisms for cell collection, with little regard to patient comfort. Consequently, most patients regard such devices as unpleasant, invasive and occasionally painful. The present invention is designed to address these issues.  
      Referring to  FIGS. 1 and 2 , an exemplary embodiment of the apparatus of the present invention is described. Device  10  is configured to conduct all steps necessary for intrauterine tissue collection while substantially reducing patient discomfort, compared to previously-known methods and apparatus. In particular, device  10  permits both application of anesthetic and cell collection with only a single insertion and removal of the medical device. An illustrative embodiment of the device of the present invention is shown in an assembled state in  FIG. 1 ; the individual components are depicted in  FIG. 2 .  
      Device  10  comprises three members: elongated outer tube  11 , inner tube  20 , and plunger  30 . Elongated outer tube  11  has anesthetic applicator  12  disposed at distal end  13  and Luer-lok fitting  14  disposed on proximal end  15 . Lumen  16  that extends from distal end  13  to proximal end  15  to provide communication between opening  18  of Luer-lok fitting  14  at the proximal end and opening  17  at the distal end.  
      Applicator  12  preferably comprises a conical resilient closed-cell foam material capable of conforming to the cervical os. Applicator  12  of device  10  differs from the hard plastic “acorns” used in previous-known devices in that foam cell is designed to conform to the anatomy of the cervical os, rather than deforming the anatomy to conform to the shape of the instrument. Applicator  12  is designed to remain in place against the cervical os during the duration of the sample collection procedure, thereby helping to deliver and retain anesthetic at that location.  
      Applicator  12  may be affixed to body  19  of outer tube  11  using any of a variety of methods, such as with biocompatible adhesive or interference fit. Applicator  12  preferably has a base diameter of approximately 15 mm and a height of approximately 15 mm. Other embodiments may vary in dimension to accommodate differences between patients.  
      Outer tube  11  preferably is essentially cylindrical and constructed of semi-rigid clear or opaque polymer, such as silicon, polyethylene, or polycarbonate, which allows visualization of the contents of lumen  16 . Although the device will function sufficiently well if constructed of metal alloy or glass, the use of polymers is preferred to avoid patient discomfort associated with the “cold” feeling of metallic instruments. In a preferred embodiment, outer tube  11  has a length of about 20 cm to 30 cm and a diameter of about 3 mm to 5 mm.  
      Referring also to  FIG. 2 , inner tube  20  is described. Inner tube  20  preferably is cylindrical and has a length that is at least 5 cm to 10 cm longer than outer tube  11 , and a diameter sufficient to permit the inner tube to be reciprocated inside lumen  16  of outer tube  11 . Inner tube  20  includes lumen  26  that extends between opening  28  at proximal end  25  and tissue collection aperture  22  disposed near distal end  23 . Although depicted in  FIG. 2  as circular, aperture  22  may have other geometries or other features, such as flanges or angled edges, to facilitate removal of a tissue sample.  
      While distal end  23  is depicted as closed in  FIGS. 1 and 2 , in alternative embodiments distal end  23  may be removed by the clinician, thereby selectively allowing communication with lumen  26 . Similarly, aperture  22  may be disposed at distal end  23 , for example, where inner tube  20  further included a pull wire or other means to articulate the distal region of inner tube  20 .  
      In a preferred embodiment, inner tube  20  has markings  24  on body  29  near proximal end  25  that enable the clinician to determine the circumferential position of aperture  22  relative to proximal end  25 . Markings  24  also may be provided to indicate depth of overall insertion or insertion relative to outer tube  11 .  
      Still referring to  FIGS. 1 and 2 , plunger  30  is configured to reciprocate within lumen  26  of inner tube  20 . Plunger  30  comprises shaft  39  connecting end portion  32  at distal end  33  with handle  34  at proximal end  35 . End portion  32  preferably is configured so that its exterior surface is similar in shape to the interior surface of lumen  26  of inner tube  20 . Because end portion  32  of plunger  30  has a geometry that approximates lumen  16  of inner tube  11 , proximal and distal displacement of end portion  32  within inner tube  11  creates negative and positive pressure differences in the volume of lumen  16  between end portion  32  and distal end  23  of inner tube  20 . These pressure differences may be equalized with passage of air, tissue, or other matter through aperture  22 .  
      Plunger  30  preferably comprises a single piece of molded polymer, although other embodiments may have multiple pieces formed of different material, such as a two-piece design with a rubber end piece  32  and a rigid wooden shaft  39 , for example. Plunger  30  preferably extends beyond the proximal end of inner tube  20  sufficiently far to allow a clinician to comfortably use handle  34  to manipulate plunger  30 . For example, plunger  30  may extend for a length of 2 cm to 3 cm beyond the proximal end of inner tube  11 , although a shorter or longer length for plunger  30  may be desired in particular case.  
      Proximal end  35  of plunger  30  includes handle  34 . Handle  34  may be simple in design, such as a continuation of shaft  39 , or more complex, such as providing an increased diameter to facilitate grip, as depicted in  FIGS. 1 and 2 . Preferably, handle  34  is approximately 2 cm to 3 cm long and has a greater diameter than shaft  39 , as such a design may facilitate manipulation by the clinician.  
      When components  11 ,  20  and  30  are assembled, distal end  33  of plunger  30  is inserted into lumen  26  of inner tube  20 , and distal end  23  of inner tube  20  is inserted into lumen  16  of outer tube  11 . As depicted in  FIG. 1 , distal end  23  of inner tube  20  extends through opening  17  of outer tube  11 . Markings  24  on body  29  of inner tube  20  permit the clinician to determine how far inner tube  20  extends beyond the distal end of outer tube  11  and also identifies the circumferential position of aperture  32 . This configuration is an appropriate configuration to collect fluid, cells, and intrauterine samples.  
      Next, a preferred method of using device  10  of the present invention is described. First, the clinician inserts distal end  13  of outer tube  11  into the patient&#39;s vaginal canal. The clinician then advances outer tube  11  and positions applicator  12  against the patient&#39;s external cervical os. Once so positioned, the clinician may attach a conventional syringe containing anesthetic to Luer-Lok fitting  14  on proximal end  15  of outer tube  11 . The clinician then may deliver the desired dosage of anesthetic, which passes through lumen  16  of outer tube  11  and to the cervical os. Applicator  12  reduces leakage of anesthetic into the vaginal space by directing the anesthetic toward the cervical os and acting as a barrier to retain the anesthetic in the uterus. Applicator  12  preferably remains in position for the duration of the sample collection procedure. At this point, either the patient or the clinician may continue to hold outer tube  11  in place until the anesthetic takes effect.  
      The clinician confirms that plunger  30  is positioned inside inner tube  20 . Once sufficient time has passed for the anesthetic to take effect, the clinician removes the syringe from Luer-Lok fitting  14  and inserts distal end  23  of inner tube  20  into opening  18  at proximal end  15  of outer tube  11 . The clinician then may refer to markings  24  and turn inner tube  20  so that aperture  22  is facing in the desired direction. Inner tube  20  and plunger  30  are advanced through lumen  16  until distal end  23  of inner tube  20  penetrates the patient&#39;s uterus and inner tube  20  extends beyond the distal end of outer tube  11 . The clinician may the position aperture  22  so that it contacts the intrauterine lining to permit collection of intrauterine cells.  
       FIG. 3  schematically represents the general orientation of device  10  when positioned within a patient. Once inner tube  20  is oriented to the clinician&#39;s satisfaction, the clinician preferably holds inner tube  20  in place and retracts plunger  30  proximally. This movement of plunger  30  reduces the pressure in lumen  26  distal to end portion, causing intrauterine tissue and fluid to be drawn through aperture  22  and into lumen  26 . The clinician then withdraws both inner tube  20  and plunger  30  in unison. Preferably, the clinician maintains the relative positions of inner tube  20  and plunger  30  during this step to prevent the tissue sample from becoming dislodged from lumen  26 .  
      Once distal end  23  of inner tube  20  has been retracted back into outer tube  11 , the clinician removes inner tube  20  from outer tube  11 . At this point, the clinician may examine the contents of lumen  26  of inner tube  20  to determine whether sufficient sample has been removed from the patient. If not, inner tube  20  and plunger  30  may be reinserted and the procedure repeated until a sufficient sample is obtained. Once a satisfactory sample has been collected, the clinician removes outer tube  11  from the patient, thereby completing the tissue collection process.  
      Referring now to  FIGS. 4 and 5 , an alternative embodiment of the present invention is described. Device  50  comprises outer tube  11 ′ and inner tube  40 . Components of device  50  similar to the embodiment of  FIGS. 1-3  are identified by like-primed numbers. Outer tube  11 ′ is similar in construction to outer tube  11  of the embodiment of  FIGS. 1 and 2 . Optionally, Luer-Lok fitting  14  of outer tube  11  may be omitted. Inner tube  40  also is similar in construction to inner tube  20  of the embodiment of  FIGS. 1 and 2 , but in the embodiment of  FIGS. 4 and 5  includes Luer-Lok fitting  44  at proximal end  45 . Fitting  44  permits inner tube  40  to be coupled to a conventional syringe (for use as a suction source), in which case no plunger is required.  
      Inner tube  40  preferably is cylindrical, at least 5 cm to 10 cm longer than outer tube  11 ′, and configured to freely reciprocate inside lumen  16 ′ of outer tube  11 ′. In a preferred embodiment, inner tube  40  has markings  24 ′ on body  29 ′ near proximal end  45  that enable the clinician to determine the circumferential position of aperture  22 ′. Markings  24 ′ also may be used to determine the depth of overall insertion of inner tube  40  or insertion of inner tube  40  relative to outer tube  11 ′.  
      A method of using device  50  is now described. First, the clinician inserts distal end  13 ′ of outer tube  11 ′ into a patient&#39;s vaginal canal. The clinician then advances outer tube  11 ′ and positions applicator  12 ′ against the patient&#39;s external cervical os. Anesthetic may then be applied by one of two methods. In a first method, the clinician delivers the anesthetic from a syringe attached to Luer-Lok fitting  14 ′ on proximal end  15 ′ of outer tube  11 ′.  
      In an alternative method, the clinician attaches a syringe containing anesthetic to the Luer-Lok fitting  44  on proximal end  45  of inner tube  40 . Distal end  23 ′ of inner tube  40  then may be inserted into lumen  16 ′ of outer tube  11 ′ through opening  18 ′. Inner tube  40  is advanced through lumen  16 ′ until it is in the vicinity of the cervical os. The clinician then depresses the syringe to release the anesthetic through inner tube  40  and aperture  22 ′. Preferably, the clinician rotates inner tube  40  as the anesthetic passes through aperture  22 ′ to allow for a more uniform application.  
      Once the anesthetic is applied, either the patient or the clinician may continue to hold outer tube  11 ′ in place until the anesthetic takes effect. If the anesthetic was distributed directly through outer tube  11 ′, the clinician removes the syringe from Luer-Lok fitting  18 ′ and inserts inner tube  40  coupled to an empty syringe via Luer-Lok fitting  44 . Inner tube  40  is inserted into opening  18 ′ and advanced until inner tube  40  is within the patient&#39;s uterus. If, instead, the anesthetic was applied via inner tube  40 , the clinician advances inner tube  40  through lumen  16 ′ so that distal end  23 ′ is within the patient&#39;s uterus.  
      Once distal end  43  of inner tube  40  is within the patient&#39;s uterus, the clinician orients aperture  22 ′ by rotating inner tube  40  and observing markings  24 ′ on body  29 ′. Inner tube  40  is held in position by grasping Luer-Lok fitting  44  and then suction is applied to lumen  26 ′ of inner tube  40  by retracting the plunger of the syringe. This suction draws fluid and/or tissue from the uterine lining through aperture  22 ′ into lumen  26 ′ of inner tube  40 . Preferably, suction is maintained while withdrawing inner tube  40  from lumen  16 ′ of outer tube  11 ′, so as to assist in separating the intrauterine tissue from the uterine wall. The clinician then completely withdraws inner tube  40  from outer tube  11 ′ to ensure sufficient sample was collected. If an insufficient sample was collected, the clinician may reinsert inner tube  40  and repeat the procedure. Once sufficient sample is collected, outer tube  11 ′ is removed from the patient.  
      The embodiment depicted in  FIGS. 4 and 5  also may be used by a clinician to direct the application of the anesthetic to the precise site that the tissue sample will be taken. This directed application of anesthetic is accomplished after the initial application of anesthetic to the cervical os. Then, inner tube  40  is further advanced into the uterine cavity. Next, the clinician applies the anesthetic while noting markings  24 ′ to determine the position of inner tube  40 . Finally, using markers  24 ′ to reposition inner tube  40  to the same location for the tissue collection, the clinician may position aperture  22 ′ at the site of localized anesthesia and proceed with the sample collection.  
      Although preferred illustrative embodiments of the present invention are described hereinabove, it will be evident to one skilled in the art that various changes and modifications may be made therein without departing from the invention. It is intended in the appended claims to cover all such changes and modifications that fall within the true spirit and scope of the invention.