Abstract:
A catheter apparatus for gaining access into the uterine cavity in order to perform minimally invasive surgery or diagnostic procedures related to a uterus and fallopian tubes, includes a single-lumen catheter; and an elongated balloon disposed distally on the single-lumen catheter for insertion into a cervical canal of the uterus. The balloon has opposing portions which occlude openings of the cervical canal when inflated. A fluid displacement sleeve is slidably disposed over the single-lumen catheter. The sleeve is moveable over the elongated balloon to inflate the portions of the balloon which are adjacent the opposite openings of the cervical canal when the balloon is inserted therein. Because there is no need for a balloon inflation lumen, the outer diameter of the catheter can be minimized and the cost of the apparatus is reduced.

Description:
RELATED APPLICATIONS  
       [0001]    Commonly-assigned, copending U.S. patent application, Ser. No. 09/782,859, entitled “Cervical Occluding Double Balloon Catheter”, filed Feb. 14, 2001.  
         [0002]    Commonly-assigned, copending U.S. patent application, Ser. No. 09/808,080, entitled “Esophageal Balloon Catheter Device”, filed Mar. 14, 2001. 
     
    
     
       FIELD OF THE INVENTION  
         [0003]    The present invention relates to a catheter apparatus and more particularly, to an access catheter apparatus that enables minimally invasive surgery to be performed in the uterus or selective examination of the fallopian tubes.  
         BACKGROUND OF THE INVENTION  
         [0004]    Access catheters can be used in non-surgical diagnostic procedures that enable the examination of the uterus and fallopian tubes. One such procedure known as hysterosonography, employs contrast agents and ultrasound imaging techniques for viewing the anatomical structures of the uterus. In hysterosonography, a fine flexible catheter equipped with an inflatable balloon is used to gain access into the uterus. This is accomplished by inserting the catheter into the cervical canal or the uterus and inflating the balloon with saline to block the cervical canal. A contrast agent, such as saline, is then injected through the catheter to fill the uterus so that it can be viewed using ultrasound imaging techniques.  
           [0005]    It may also be desirable to use an access catheter to gain access into the uterus for the purpose of carrying out a minimally invasive surgical procedure, such as a biopsy. In such a procedure, the access catheter is inserted through the cervix into the uterus. A contrast agent, such as saline or water, is injected through the catheter to fill the uterus so that any suspected pathology can be viewed using ultrasound imaging techniques. A surgical instrument, such as a biopsy needle or snare, is then passed through the catheter and into the uterus and manipulated to perform the surgery.  
           [0006]    Another desirable use for an access catheter is as a conduit for a smaller diameter catheter used for selective examination of fallopian tubes. Such a catheter is passed through the access catheter and manipulated into the entrance of either fallopian tube. Contrast medium is then injected through the inner catheter to determine the degree of patency of the tube. In this application, X-ray techniques can be used as well as ultrasound procedures.  
           [0007]    Access catheters that are suitable for performing minimally invasive surgery in the uterus or selective examination of the fallopian tubes must be stable when positioned in the cervical canal. Previous guided access catheter designs typically employ two inflatable, distally located balloons for stabilizing the catheter. Such catheters are constructed with multiple lumens, two for inflating the balloons, one for inserting the surgical instrument, and one for injecting the contrast agent. These multi-lumen catheter designs necessarily have relatively large outer diameters, which typically measure about 4 mm (12 french). The relatively large outer diameters of these prior catheter designs can cause patient discomfort and or trauma. Moreover, these designs are relatively complex, thus increasing the cost of the device.  
           [0008]    Accordingly, an access catheter apparatus for performing minimally invasive surgery in the uterus or selective examination of the fallopian tubes is needed that overcomes the problems associated with previous access catheter designs.  
         SUMMARY OF THE INVENTION  
         [0009]    The invention is directed to a catheter apparatus for gaining access into the uterine cavity in order to perform minimally invasive surgery in a uterus or selective examination of the fallopian tubes. The catheter apparatus comprises a single-lumen tubular body, and an elongated balloon disposed distally on the tubular body for insertion into a cervical canal of the uterus. The balloon is affixed to the tubular body and sealed with a fixed residual volume of fluid. The balloon includes opposing portions that occlude openings of the cervical canal when fluid displacement in one portion of the balloon causes other portions of the balloon to inflate.  
           [0010]    One aspect of the catheter apparatus involves a fluid displacement sleeve, which is slidably disposed over the single-lumen tubular body. The sleeve is moveable over the elongated balloon to displace fluid in the proximal portion of the balloon thereby inflating the portions of the balloon which are adjacent the opposite openings of the cervical canal when the balloon is inserted therein.  
           [0011]    In another aspect of the catheter apparatus, the inflated portions of the balloon define a barbell-shape balloon structure when the balloon is inflated in the cervical canal.  
           [0012]    In a further aspect of the catheter apparatus, a surgical instrument insertion adapter assembly is disposed at a proximal end of the single-lumen tubular body.  
           [0013]    In still a further aspect of the catheter apparatus, a removable stylet is optionally provided for stiffening the single-lumen tubular body to facilitate insertion thereof in the cervical canal. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]    The advantages, nature, and various additional features of the invention will appear more fully upon consideration of the illustrative embodiments now to be described in detail in connection with accompanying drawings wherein:  
         [0015]    [0015]FIG. 1 is an elevational view of an access catheter apparatus according to an embodiment of the invention;  
         [0016]    [0016]FIG. 2 is a sectional view of the catheter body of the apparatus of FIG. 1;  
         [0017]    [0017]FIG. 3 is an elevational view of the access catheter apparatus with the removable stylet assembly inserted through the catheter body;  
         [0018]    [0018]FIG. 4A is a sectional view of the removable surgical instrument insertion adapter assembly;  
         [0019]    [0019]FIG. 4B is an exploded sectional view of the removable surgical instrument insertion adapter assembly of FIG. 4A;  
         [0020]    [0020]FIG. 4C is a sectional view of the removable surgical instrument insertion adapter assembly with a surgical instrument inserted therethrough;  
         [0021]    [0021]FIG. 5 is a diagrammatic view of the catheter apparatus inserted into the cervical canal of a subject uterus prior to inflation of the balloon portions;  
         [0022]    [0022]FIG. 6 is a diagrammatic view of the catheter apparatus inserted into the cervical canal of a subject uterus after inflation of the balloon portions; and  
         [0023]    [0023]FIG. 7 is a diagrammatic view of the catheter apparatus inserted into the cervical canal of a subject uterus after attachment of the removable surgical instrument insertion adapter assembly to the catheter body. This view shows how the catheter apparatus is used for gaining access into the uterine cavity in order to perform minimally invasive surgery in a uterus and its associated fallopian with a surgical instrument.  
         [0024]    It should be understood that the drawings are for purposes of illustrating the concepts of the invention and are not necessarily to scale. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0025]    Referring to the drawings wherein like reference numerals identify similar or like elements throughout the several views, and initially to FIG. 1, there is shown an access catheter apparatus  10  according to an exemplary embodiment of the invention. The catheter apparatus  10  generally comprises a flexible tubular catheter body  11 , a semi-rigid fluid displacement sleeve  12 , a surgical instrument insertion adapter assembly  13 , and optionally, a removable stylet assembly  14 .  
         [0026]    As collectively shown in FIGS. 1 and 2, the tubular catheter body  11  includes a distal end  15  and a proximal end  16 . (“Distal end” refers to the end furthest from the person holding the apparatus, and “proximal end” refers to the end closest to the holder of the apparatus.) An elongated inflatable balloon  21  (shown in the deflated state), about 4 inches in length L balloon , is sealingly affixed to and encloses a distal portion of the catheter body  11 . The balloon  21  may be made from an elastomeric material such as polyurethane, poly(vinyl chloride) or any other suitable material. The balloon  21  is sealed with a fixed residual volume of fluid, e.g., air and/or saline solution. The elongated construction of the balloon  21  enables it to be positioned in the cervical canal such that distal and proximal end portions  21   a ,  21   b  of the balloon  21  extend past the openings of the canal (FIGS. 5-7). The distal and proximal portions  21   a ,  21   b  of the balloon  21  are inflated and deflated by the operation of the fluid displacement sleeve  12  as will described further on. When inflated, the two balloon portions  21   a ,  21   b  permit stable positioning of the catheter body  11  in the cervical canal. The portion of the balloon connecting the two portions  21   a ,  21   b , which resides in the cervical canal, inflates slightly within the canal, as it is restricted by cervical tissue.  
         [0027]    The catheter body  11  includes a single lumen  17  that extends the entire length L body  thereof and communicates with the external environment via distal opening  18  and proximal opening  19  at the distal and proximal ends  15 ,  16  of the body  11 . The lumen  17  provides a fluid communication path for injecting a diagnostic fluid, such as saline or a contrast medium, into the uterine cavity and provides a means for accessing the uterine cavity with a surgical instrument to perform a surgical procedure, or accessing the uterine cavity with other type of devices, such as diagnostic instruments. Fluid injection is completely independent of the mechanism of balloon inflation. By way of example and not limitation, the lumen  17  may have an inner diameter of approximately 1.9 mm. Such an inner diameter enables, for example, a surgical instrument with a maximum outer diameter of up to about 1.66 mm (5 french) to be slidably inserted through the lumen  17  and into the uterine cavity. The surgical instrument insertion adapter assembly  13  is integrally attached at the proximal end  16  of the catheter body  11 . Alternatively, the surgical instrument insertion adapter assembly  13  may be attached at the proximal end  16  of the catheter body  11  using a Luer lock arrangement. The catheter body  11  may be made from an opaque or clear flexible material such as polyurethane or any other suitable material.  
         [0028]    As one of ordinary skill in the art will appreciate, no additional lumens are required within the catheter body  11  of the present invention to inflate or deflate the balloon  21  because the balloon  21  sealingly contains the fixed residual volume of fluid, which is displaced by operation of the fluid displacement sleeve  12  to inflate or deflate the balloon  21 . This feature advantageously permits the outside diameter of the catheter body  11  to be reduced. The catheter body  11  has an outer diameter, which is typically only about 2.3 mm (7 french). This is in contrast to conventional multi-lumen catheter designs which have relatively large outer diameters, that typically measure about 4 mm (12 french). The slimmer catheter body  11  of the present invention will provide a beneficial reduction in patient discomfort and or trauma. Moreover, the less complex single lumen design of the catheter body  11  decreases the cost of the catheter apparatus  10 , hence, reducing the cost of the surgical procedure.  
         [0029]    Although the outer diameter of the catheter body  11  is typically about 2.3 mm in other embodiments of the invention, the outer diameter may be smaller or larger. The specific dimension of the outer diameter of the catheter body  11  depends mainly upon the diametrical dimensions of the instrument intended to be inserted through the catheter apparatus.  
         [0030]    As shown in FIG. 1, the optional stylet assembly  14  of the catheter apparatus  10  typically comprises a wire  22  (stylet), the proximal end of which is permanently affixed to a central portion of a holder  23 . The stylet  22  extends through the lumen  17  of the catheter body  11  from the proximal end  16  thereof to a point approximately adjacent a point 1 to 2 cm from the distal end thereof, when inserted in the catheter body  11 . The stylet  22  is slidably threaded into the lumen  17  of the catheter body  11  as shown in FIG. 3. The stylet assembly  14  may be employed to prevent the catheter apparatus  10  from bending and flexing excessively in the vagina, in cases where insertion of the catheter apparatus  10  into the cervical canal is difficult. Once the catheter apparatus  10  has been inserted into the cervical canal, the stylet assembly  14  can then be removed.  
         [0031]    Referring again to FIGS. 1 and 2, the fluid displacement sleeve  12  of the catheter apparatus  10  has a distal end  24  and a proximal end  25 . The fluid displacement sleeve  12  may be made from any suitable semi-rigid material such as polypropylene. The distal end  24  of the sleeve  12  terminates with an outwardly extending rim  26 . The fluid displacement sleeve  12  has a length L sleeve  which may be about 40% percent of the length L body  of the catheter body  11 . This enables the fluid displacement sleeve  12  to be slidably moved along the catheter body  11  in both the distal and proximal directions to inflate and deflate the elongated balloon  21 .  
         [0032]    Referring now to FIG. 4A, the surgical instrument insertion adapter assembly  13  includes a Y-shape tubing member  30  having main leg  31  and an angled side port  32 . The angled side port  32  extends back toward a proximal end  33  of the main leg  31  and is adapted for removably coupling a syringe (FIG. 7).  
         [0033]    As best seen in FIG. 4B, the proximal end  33  of the main leg  31  may be adapted for threadedly receiving a conventional Touhy Borst assembly  40  by configuring the proximal end  33  of the main leg  31  as a conventional female Luer hub. The Touhy Borst assembly  40  typically includes a cylindrical body  41  with distal and proximal ends  42 ,  43 . The distal end  42  includes a male Luer hub  44  that mates with a female Luer hub  45  formed by the proximal end  33  of the main leg  31 . The outer surface  46  of the cylindrical body  41  at the proximal end  43  thereof includes a thread arrangement  47 . An elastomeric bushing  48  is disposed within the cylindrical body  41  between the hub  44  and a cap member  49 . The cap member  49  includes a tubular plug element  50  that compresses the bushing  48  against the hub  44  when the cap member  49  is screwed down onto the cylindrical body  41 , thereby reducing the inner diameter of the bushing  48 .  
         [0034]    As shown in FIG. 4C, when a surgical instrument  60  is inserted through the Touhy Borst assembly  40  and the cap member  49  is screwed down sufficiently tight, the bushing  48  creates a substantially fluid tight seal around the surgical instrument  60 , thereby preventing excessive fluid leakage out the cap member  49  while still allowing the surgical instrument  60  to be manipulated within the catheter apparatus by rotating it, pushing it in, and pulling it out. The Touhy Borst assembly  40  may also be used to create a substantially fluid tight seal around the stylet  22  of the stylet assembly  14 , when the stylet assembly  14  is used.  
         [0035]    Referring to FIG. 5, the catheter apparatus  10  may be operated by positioning the fluid displacement sleeve  12  proximally on the catheter body  11 , introducing the catheter apparatus  10  into the vaginal canal and inserting the distal end  15  of the catheter body  11  through the cervical canal so that the distal and proximal portions  21   a ,  21   b  of the balloon are positioned adjacent the exterior and interior OS of the cervical canal. If necessary or desired, the stylet assembly  14  (not shown) can be used to stiffen the catheter body  11  to aid in the insertion of the catheter body  11  into the cervical canal. The stylet assembly  14  may be assembled to the catheter body  11  by inserting the distal end of the stylet  22  into and through the surgical instrument insertion adapter assembly  13  and threading the stylet  22  through the lumen  17  of the catheter body  11  via the opening  19  at the proximal end  16  thereof.  
         [0036]    As shown in FIG. 6, the distal and proximal portions  21   a ,  21   b  of the balloon  21  are inflated by sliding the fluid displacement sleeve  12  distally along the catheter body  11  so that the sleeve  12  slides over the end of the proximal portion  21   b  of the balloon  21 . As the sleeve slides over the proximal portion  21   b  of the balloon  21 , the fixed volume of fluid (e.g. air or saline) sealingly contained therein is displaced or redistributed to inflate and expand the distal and proximal portions  21   a ,  21   b  of the balloon  21 , thereby forming a barbell-shape balloon structure which conforms to and thus occludes the exterior and interior OS of the cervical canal and sealingly affixes and stabilizes the catheter apparatus  10  in place therein. If used, the stylet assembly  14  can now be removed from the catheter body  11 .  
         [0037]    As shown in FIG. 7, an echogenic surgical instrument  60 , such as a biopsy needle or snare, is then threaded through the Touhy Borst assembly  40 , the main leg  31  of the tubing member  30 , and the lumen  17  (not visible) of the catheter body  11 . The cap  49  of the Touhy Borst assembly  40  is then tightened sufficiently to create a fluid seal around the instrument  60  but still allowing in-and-out, and rotational movement of the instrument  60 , and a syringe  70  filled with a contrast medium is coupled to the side port  32  of the adapter assembly  13 . The contrast medium in the syringe  70  is injected into the uterine cavity of the uterus to enable imaging of the uterus and the distal end  61  of the surgical instrument  60  during the surgical procedure.  
         [0038]    When it is desirable to deflate the portions of the balloon  21 , the fluid displacement sleeve  12  is moved proximally along the catheter body  11 . This allows the fluid in the distal and proximal balloon portions  21   a ,  21   b  to redistribute throughout the entire interior of the balloon  21  so that the catheter apparatus  10  can be withdrawn through the cervix  80 .  
         [0039]    Although the access catheter apparatus  10  has been described for surgical diagnostic entry into the uterine cavity, one of ordinary skill in the art will recognize its usefulness in other related procedures.  
         [0040]    Further, while the foregoing invention has been described with reference to the above embodiments, various modifications and changes can be made without departing from the spirit of the invention. Accordingly, all such modifications and changes are considered to be within the scope of the appended claims.