Abstract:
An elastic band ligation device for treatment of hemorrhoids including an inner tubular member for retaining a stretched elastic band over the front end thereof, a plunger in the inner tubular member with a handle for sliding the plunger to generate a suction for drawing hemorrhoidal tissue into the inner tubular member. An obturator connected to the plunger is provided within the inner tubular member. An outer tubular pusher sleeve with a limited friction fit is provided over the inner tubular member, the end of outer tubular pusher sleeve being adjacent the stretched elastic band. The outer pusher sleeve has a thumb pusher to allow the operator to push the outer pusher sleeve towards the front end of the inner tubular member or to secure the outer pusher sleeve and withdraw the inner tubular member, which deploys the elastic band on the hemorrhoidal tissue.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to the treatment of hemorrhoids by elastic band ligation. More specifically the invention relates to an elastic band ligation device that is provided with an integrated obturator which provides for more controlled elastic band deployment and less discomfort for the patient. 
     Commonly assigned patent applications entitled ELASTIC BAND LIGATION DEVICE WITH LOCKING MECHANISM AND METHOD FOR TREATMENT OF HEMORRHOIDS (U.S. application Ser. No. 13/972,168) and ELASTIC BAND LIGATION DEVICE WITH ANTI-PINCH FEATURE AND METHOD FOR TREATMENT OF HEMORRHOIDS (U.S. application Ser. No. 13/972,202) are filed simultaneously herewith, the entire disclosures of which are hereby incorporated by reference herewith. 
     Treatment of hemorrhoids by elastic band ligation typically involves placing an elastic band on hemorrhoidal tissue in the rectum well above the “dentate line” (the junction of the sensitive squamous epithelium known as the “anoderm” and the insensitive lining of the rectum known as the “mucosa”), where there is little sensation. The tissue trapped in the band is cut off from its blood supply, degenerates and is sloughed, and the elastic band along with the sloughed tissue is passed with bowel motions. More importantly, however, the resulting healing process causes the tissue in the vicinity to become fixed, and prolapse of the hemorrhoidal tissue is minimized. This fixation of the tissue serves to eliminate the hemorrhoidal symptoms. 
     Many devices exist on the market utilizing the elastic band ligation technique. Examples are U.S. Pat. No. 5,203,863 to Bidoia, U.S. Pat. No. 5,122,149 to Broome, U.S. Pat. No. 5,158,563 to Cosman and U.S. Pat. No. 5,741,273 to O&#39;Regan. The devices disclosed in U.S. Pat. No. 5,203,863 to Bidoia, U.S. Pat. No. 5,122,149 to Broome, U.S. Pat. No. 5,158,563 to Cosman are generally designed to be used in conjunction with an instrument such as a proctoscope or anoscope to directly see the area to be banded. In some cases, it is necessary to employ an assistant to hold the proctoscope or anoscope. However, the use of these scopes, which are generally larger in diameter than banding apparatus, can cause considerable discomfort to a patient and more specifically to one who is suffering symptoms of hemorrhoids and other associated issues. 
     The device disclosed in U.S. Pat. No. 5,741,273 to O&#39;Regan relates to an elastic band ligation device for treatment of hemorrhoids that may be used without directly seeing the site for banding. Thus, it may be used without a proctoscope or anoscope or any other type of scope or viewing technique. Therefore, because the device can be inserted into the rectum and positioned appropriately without simultaneous visualization, or the need for any type of scope, the banding procedure performed in this manner causes less discomfort to the patient. This technique also allows for a more proximal placement of the elastic band, which increases the technique&#39;s efficacy as well as causing less discomfort and fewer complications. This device has a suction device incorporated therein to draw hemorrhoidal tissue into an aperture for banding without requiring a second operator or connection to an aspirator. 
     Ligation is typically performed by initially inspecting the site through a small scope such as a sigmoidoscope, anoscope, proctoscope or other type of scope and making a mental note as to the area where the band should optimally be placed. The scope is then removed and the ligation device is placed in the rectum. This is known as the “Blind” or “Touch” technique. 
     An alternative application is to visualize the area with an anoscope and insert the banding through the lumen of the anoscope and band directly. This can be done if the operator prefers a direct visual approach. This is known as the “Trans-anoscopic” or “visual” technique. 
     The front end of the device is inserted well past the site for banding. Then, the device is gently withdrawn back to the banding site, when a palpable “ridge” on the outer surface of the outer tubular member (“pusher sleeve”) can be felt at the anal verge. The device then is angled acutely to point in the direction of the hemorrhoid to be treated. In larger patients, the operator may choose to place the device 1-2 cm further in through the anus prior to “aiming” the device towards the hemorrhoid to be treated. 
     However, it has been found that prior devices suffer from the drawback that the elastic band(s) may undergo premature deployment, with the result that it is necessary to withdraw the device, recover the deployed elastic band within the rectum and begin the procedure again. This gives rise to delays and additional discomfort to the patient. A need exists, therefore, for an improved elastic band ligation device in which premature deployment of the elastic band is prevented. The present invention seeks to satisfy that need. 
     BRIEF DESCRIPTION OF THE INVENTION 
     The present invention provides an elastic band ligation device for treatment of hemorrhoidal tissue comprising an inner tubular member having a front end and a rear end, for retaining a stretched elastic band over the front end thereof, the front end having an opening, a plunger in the inner tubular member with a handle extending away from the front end of the inner tubular member, the handle for sliding the plunger away from the front end of the inner tubular member to provide a suction for drawing hemorrhoidal tissue into the inner tubular member through the opening at the front end, an obturator within the inner tubular member, an outer tubular pusher sleeve configured to provide a limited friction fit over the inner tubular member, with an external end of the outer tubular pusher sleeve adjacent the stretched elastic band, and having an opposite end of the outer tubular pusher sleeve provided with thumb pusher for an operator to push the outer tubular pusher sleeve towards the front end of the inner tubular member and release the elastic band from the front end of the inner tubular member to engage hemorrhoidal tissue extending through the opening in the inner tubular member. 
     The term “a limited friction fit” as used herein means that the outer tubular pusher sleeve exerts sufficient friction against the inner tubular member such that the two components do not freely slide with respect to each other but require gentle hand-applied pressure to move one relative to the other. 
     In one embodiment, the thumb pusher on the outer tubular pusher sleeve locking mechanism includes a manually actuated tab which is engageable with a locking ring on the inner tubular member for locking the outer tubular pusher sleeve to the inner tubular member to prevent relative movement of the outer sleeve and inner tubular member until the outer pusher sleeve is unlocked by the user, thereby preventing premature deployment of an elastic band. 
     In another embodiment, the device may include an anti-pinch feature which reduces the risk of the patient&#39;s tissue being trapped as the obturator is retracted into the device. 
     In a further embodiment, the ligation device is made of plastic and is disposable. Thus, once it has been used it is discarded and does not have to be sterilized. In another embodiment, the ligation device is made of metal and may be sterilized after each use. 
     The disposable elastic band ligation device of the invention may be used in a doctor&#39;s office and does not generally require the administration to the patient of any form of anesthetic. One to three elastic bands are generally placed at each patient visit and as many as six bands may be required in total, particularly in advanced cases. 
     The obturator disposed within the inner tubular member is connected to the plunger, and is typically integrally formed with the plunger a single unit. The obturator is provided with a rounded smooth end which may be induced to protrude beyond the front end of the inner tubular member by movement of the plunger. The purpose of the obturator is to facilitate access of the ligation device into the rectum of the patient with reduced discomfort to the patient, with minimal training of the physician, and with no requirement for the use of additional piece(s) of equipment. 
     In another embodiment, the ligation device of the invention may be provided with a separable elastic band introducer device which facilitates introduction of the elastic band(s) onto the front end of the device. In one embodiment, the band introducer is in the general shape of a cone and comprises a front tapered section, a rear section dimensioned such that it can be connected to the front end of the inner tubular member, and a center section disposed between the front and rear sections having an external dimension corresponding to that of the front end of the inner tubular member. The band introducer may be provided with surface channels extending longitudinally to permit insertion of a finger(s) of the user below the band(s) to manipulate the band(s) onto and/or off of the introducer. In use, the rear end of the introducer is connected to the front end of the inner tubular member and an elastic band(s) is (are) rolled over the tapered front section and over the central section onto the front end of the inner tubular member. Once the band(s) has been placed on the front end of the inner tubular member, the introducer is removed prior to use of the ligation device. 
     An additional feature is the use, in the plastic version of the ligation device, of a plastic retention fixed ring on the inside of the proximal end of the inner tubular member for preventing the plunger from being withdrawn from the inner tubular member and thus preventing the possibility of the instrument being cleaned and reused. Reuse of the device may be possible when the ligator is fabricated from metal, such as stainless steel, which can be sterilized between uses. 
     A further feature, again in connection with the plastic version of the ligation device, is the use of a treated slightly roughened inside plastic or a material such as Plexiglas SL7 on the inside of the inner tubular member which turns opaque after attempted cleaning and, thus, provides a visual guide that the ligator has been used in one patient and should not be reused. 
     A yet further feature of the invention resides in a method of treating hemorrhoidal tissue in a patient in need of such treatment. The method comprises the steps of: (a) providing an elastic band ligation device of the invention; b) applying at least one elastic band over the front end of the inner tubular member; (c) pushing the plunger into the inner tubular member to cause the end of the obturator to at least partially protrude from the end of the device; (d) inserting the device carrying the one elastic band into the rectum of a patient; (e) adjusting the position of the device to arrange the opening at the end of the device to be in direct alignment with the hemorrhoidal tissue; (f) withdrawing the plunger and obturator to exert suction on the hemorrhoidal tissue and draw it through the opening into the inner tubular member; locking the plunger in place and allowing the engaged ligator to sit in order to allow for more tissue to move inside the inner tubular member; and (g) pushing the outer tubular pusher sleeve to engage the outer tubular pusher sleeve against the elastic band to urge the elastic band onto the hemorrhoidal tissue. 
     The device will typically be supplied to end users in the band loading position, that is with the plunger/obturator pulled back to allow for the user to attach the band loading cone, push band(s) over and onto the main body of the ligator and remove the band loading cone. Prior to insertion, the plunger is completely depressed, exposing the smooth, rounded end of the obturator, which will help in the comfortable passage of the ligator into the anorectum. Following insertion of the device into the anus of the patient, the plunger is pulled back to the “ready to draw material” position, which will be the same location as the band loading position and will be marked by: a slight bump/feel in the plunger as in rides over a small detent/ring and/or a mark on the plunger that will align with the end of the ligator or a line or mark on the ligator, and/or texture/color change that will denote visually or by feel that the correct location has been reached. Tissue to be banded is located, and the plunger is pulled back to draw tissue into the inner tubular member until the inner ring is engaged. The device is oscillated 90 to 180 degrees in either direction to ensure tissue is captured properly. The band is deployed by either pushing the pusher forward or by securing the pusher and withdrawing the inner tubular member until the band has deployed. The entire device is then withdrawn. 
     The plunger with the integrated obturator may be manufactured: (i) as an all-in-one piece with an overmolded gasket material (2 shot molding), (ii) as one piece with an assembly of the gasket, (iii) as two pieces joined together either through bonding, mechanical snap or welding with an assembly of the gasket. 
     An additional aspect of the invention provides a non-latex elastic band for use in the treatment of patients who exhibit or may exhibit a latex allergic reaction. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side cross-sectional view of a first embodiment of ligation device of the present invention; 
         FIG. 2A  is an enlarged side view of the of the outer pusher sleeve locking mechanism; 
         FIG. 2B  is a cross-sectional view of the end of the device showing the end of the obturator partially protruding from the end of the device; 
         FIG. 3A  is a perspective view of the outer pusher sleeve showing the tab of the locking mechanism and an enlarged inset view thereof; 
         FIG. 3B  is a side view of the outer pusher sleeve; 
         FIG. 3C  is a top view of the outer pusher sleeve; 
         FIG. 3D  is a cross-sectional view of the outer pusher sleeve along the line  3 D- 3 D in  FIG. 3C ; 
         FIG. 3E  is a view from the distal end of the outer pusher sleeve; 
         FIG. 3F  is a view from the proximal end of the outer pusher sleeve; 
         FIG. 4  is side view of the inner tubular member showing a locking ring on the outer circumference thereof; 
         FIG. 5A  is a side view of an embodiment of the ligation device of the invention showing the obturator extending from the end of the inner tubular member and the outer pusher sleeve locking mechanism engaged with the locking ring on the outer circumference of the inner tubular member (an elastic band introducer is also shown adjacent the distal end of the device); 
         FIG. 5B  is a view from the distal end of the device shown in  FIG. 5A ; 
         FIG. 6A  is perspective view of the elastic band introducer showing surface ribs and channels; 
         FIG. 6B  is a side view of the elastic band introducer of  FIG. 6A ; 
         FIG. 6C  is a cross-sectional view of the elastic band introducer along the line  6 C- 6 C in  FIG. 6B ; 
         FIG. 7  is an side view of the device showing the locking mechanism on the outer pusher sleeve; 
         FIG. 8  is a cross-sectional view of the device showing the obturator partially withdrawn inside the device; 
         FIG. 9  is a cross-sectional view of the device showing the obturator fully withdrawn inside the device; 
         FIG. 10  is a cross-sectional view of the device showing the obturator protruding from the end of the device; 
         FIG. 11  is a cross-sectional view showing the elastic band introducer on the distal end of the device; 
         FIG. 12  is a side view of an obturator. 
         FIGS. 13 and 14  are side views of an alternative embodiment showing a differently shaped end for the obturator; 
         FIG. 15  is a cross-sectional view along line  15 - 15  of  FIG. 14 ; 
         FIG. 16  is a cross-sectional view of the circled portion of  FIG. 15 ; 
         FIG. 17  is a cross-sectional view of the circled portion of  FIG. 16 ; 
         FIGS. 18 and 19  are side views of another embodiment showing a differently shaped end for the obturator; 
         FIG. 20  is a cross-sectional view along line  20 - 20  of  FIG. 19 ; 
         FIG. 21  is a cross-sectional view of the circled portion of  FIG. 20 ; 
         FIG. 22  is a cross-sectional view of the circled portion of  FIG. 21 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to the drawings,  FIG. 1  shows a cross-sectional view of a first embodiment of a ligation device of the invention, generally referenced  2 , comprising a plastic inner tubular member  4  having a convergent tubular section  6  with an inner surface  9  and an integrally formed straight cylindrical section  8 . The convergent tubular section  6  has a rear end  10  and a front end  12  for retaining a stretched elastic band  14  over the front end  12  thereof. 
     In the embodiment illustrated in  FIG. 1 , the inner tubular member  4  has a convergent tubular configuration extending continuously from the rear end  10  to the front end  12  and for a sufficient distance to facilitate insertion into the rectum of a patient. 
     A plunger  16  is slideably disposed in the cylindrical section  8 , and has a stem center section  18 , a head  20  at one end of a stem section  18  and a handle  22  at the other end of the stem section  18  and extending away from the head  20 . The head  20  is typically fabricated from rubber and is adapted for sealingly engaging with an inner wall of the cylindrical section  8 . In the embodiment shown in  FIG. 1 , a sealing member  23  is mounted on the head  20  for sealingly engaging with the inner wall  24  of the cylindrical section  8 . 
     The plunger  16  includes an obturator  26  disposed internally of the inner tubular member. The obturator  26  is connected with the plunger  16  and is typically integrally formed therewith. The obturator  26  is provided with a rounded end portion  28  which by movement of the plunger may protrude beyond the end  12  of the inner tubular member, through opening  13 , as shown in  FIG. 1 , or may be positioned within the interior of the inner tubular member, as shown in  FIGS. 8 and 9  (discussed below). The purpose of the obturator  26  is to facilitate access of the ligation device when inserted into the rectum of a patient. 
     The handle  22  permits the plunger  16  to be slid away from the front end  12  of the inner tubular member  4  to provide a suction for drawing hemorrhoidal tissue into the inner tubular member  4  through the opening  13  at the front end  12 . The opening  13  may be slightly smaller in diameter than the inner tubular member  4 . In another embodiment, the cylindrical section  8  and inner tubular member  4  may be separate components joined together. 
     A plastic outer tubular pusher sleeve  30  is provided and a straight cylindrical section  32  and a tapering tubular section  34  corresponding to the taper of the convergent section of the inner tubular member  4 . The outer tubular pusher sleeve  30  has a limited friction fit over the length of the inner tubular member  4 , and has an external end  36  adjacent the stretched elastic band  14  and an opposite end  38 . 
     In one embodiment, the opposite end  38  may be provided with a locking mechanism  40  shown in  FIG. 2A  and generally referenced  40 . The locking mechanism  40  includes a tab  42  engageable with a locking ring  44  provided on the exterior surface of the inner tubular member  4 . The locking ring has an abutment surface  48  extending at 90 degrees to the outer surface of the inner tubular member. The tab  42  is provided with a lug  46  which extends transversely, at 90 degrees, from the tab  42  towards the inner tubular member  4  and abuts against the abutment surface  48 , thereby preventing movement of the outer pusher sleeve towards the front end of the device. Upon pushing the tab  42  away from the inner tubular member  4 , the lug  46  moves out of abutting relationship with the abutment surface  48  which allows the outer pusher sleeve to be moved relative to the inner tubular member  4  towards the front end of the device, thereby to push an elastic band off the front end of the device onto hemorrhoidal tissue. The locking mechanism  40  ensures that unintentional deployment of the elastic band as a result of movement of the outer pusher sleeve towards the front end of the device does not occur until the outer pusher sleeve is unlocked by the user. 
       FIG. 2B  shows in cross-section the distal end of the inner tubular member end  4  with the end  28  of the obturator partially protruding from the opening  13 . The outer surface  11  of the end  28  is convergent towards the distal tip of the obturator, creating an angle of 5-25 degrees between the outer surface  11  of the obturator end  28  and the inner surface  9  of the inner tubular member  4 . This feature serves to reduce pinching of tissue when the obturator  26  is moved relative to the inner tubular member, particularly when the obturator is withdrawn into the inner tubular member  4 . This anti-pinch feature allows gaps to increase as components move together, or allows for no gap as they move together, thereby minimizing the risk of pinching of tissue as the end of the obturator emerges from or is retracted into the inner tubular member  4 . In the illustrated arrangement, pinching is reduced as the pinch area increases allowing material to move away freely. As indicated in  FIG. 2B , the angle between the outer surface of the end  28  and the inner surface of the inner tubular member is typically in the range of 5-25 degrees, for example 5-10 degrees, and is typically about 30 degrees or less. 
       FIG. 3A  shows the tab  42  and the lug  46 . Cut-outs  47 ′ and  47 ″ are provided to permit adjustment to tune the force required to deflect the tab  42  away from the inner tubular member. The highest force would be a configuration with no cut-out, decreasing in force as the cut-outs deepen and widen. 
       FIG. 3B  is a side view of the outer pusher sleeve  30  and  FIG. 3C  is a top view of the outer pusher sleeve  30 .  FIG. 3D  is a cross-sectional view of the outer pusher sleeve  30  along the line  3 D- 3 D in  FIG. 3C  and  FIG. 3E  is a view from the distal end of the outer pusher sleeve  30 .  FIG. 3F  is a view from the proximal end of the outer pusher sleeve  30 . 
       FIG. 4  shows the inner tubular member  4  with the locking ring  44  disposed on the outer circumference thereof. The shape of the locking ring is shown in greater detail in  FIG. 2A . 
       FIG. 5A  shows a circumferential ring marker  50  provided on the external circumference of the outer tubular pusher sleeve  30 . This serves as a depth marker to the user with regard to the extent of insertion of the device into the rectum of the patient.  FIG. 5A  also shows the obturator  26  protruding from the end of the inner tubular member.  FIG. 5B  is a view from the distal end of the device shown in  FIG. 5A . 
       FIGS. 6A-6C  show views of the elastic band introducer  60 .  FIG. 6A  is perspective view of the elastic band introducer  60  showing surface ribs  61  and channels  63  on the tapered surface  65 .  FIG. 6B  is a side view of the elastic band introducer of  FIG. 6A  and  FIG. 6C  is a cross-sectional view of the elastic band introducer along the line  6 C- 6 C in  FIG. 6B . The tapered surface  65  of the introducer  60  facilitates loading of elastic bands thereon by rolling the bands onto flat region  67  of the introducer prior to pushing the bands onto the inner tubular member  4 . 
       FIG. 7  shows a side view of the device showing the locking mechanism  40  and cut outs  47 ′ and  47 ″. In the embodiment shown, the locking mechanism  40  is engaged with the locking ring  44  on the inner tubular member  4 . 
       FIG. 8  is a cross-sectional view of the device showing the obturator  26  partially withdrawn inside the inner tubular member  4 , and  FIG. 9  is a cross-sectional view of the device showing the obturator  26  fully withdrawn inside the inner tubular member  4 .  FIG. 10  is a cross-sectional view of the device showing the obturator  26  protruding from the end of the inner tubular member  4 . 
       FIG. 11  is a cross-sectional view of the elastic band introducer  60  on the distal end of the inner tubular member  4  whereby the end of the inner tubular member  4  is received within slot  69  of the introducer  60 . In this way, elastic band(s)  14  loaded on the flat region  67  can be rolled onto the outer surface of the inner tubular member downstream of the distal end of the outer tubular pusher sleeve  30 . 
       FIG. 12  is a side view of a combined plunger  16  and obturator  26  for use in the device of the invention. As noted earlier, the plunger and obturator may be separate items or may be integrally formed in one piece, as shown in  FIG. 12 . The rounded end section  28  facilitates more comfortable access of the ligation device into the rectum of a patient. 
       FIGS. 13 and 14  are side views of an alternative embodiment showing a differently shaped end for the obturator  26 . In this embodiment, the distal end of the obturator has a region of reduced diameter  26 ′ towards the tip to further facilitate entry of the device into the rectum of the patient and to reduce the incidence of pinching of tissue as the obturator is withdrawn into the device after deployment of a band onto the hemorrhoidal tissue. 
       FIG. 15  is a cross-sectional view along line  15 - 15  of  FIG. 14 .  FIG. 16  is a cross-sectional view of the circled portion of  FIG. 15  showing in greater detail the region  26 ′ of reduced diameter towards the obturator tip. 
       FIG. 17  is a cross-sectional view of the circled portion of  FIG. 16  showing an alternative embodiment whereby a flexible anti-pinch wiper element  70  suitably of a thin plastics material is connected to, or integrally formed with, the end of the inner tubular member  4 . The flexible anti-pinch element  70  is disposed such it abuts against the outer surface of the end of the obturator and prevents tissue from being trapped or pinched between the outer surface of the end of the obturator and the inner surface of the inner tubular member  4 . 
       FIGS. 18 and 19  are side views of another embodiment showing a differently shaped end for the obturator. In this embodiment, the end  72  has parallel walls  74  rounded at  76  at the tip of the obturator, which reduces the incidence of pinching of tissue. 
       FIG. 20  is a cross-sectional view along line  20 - 20  of  FIG. 19 .  FIG. 21  is a cross-sectional view of the circled portion of  FIG. 20  showing in greater detail the region the configuration of the obturator tip  72 . 
       FIG. 22  is a cross-sectional view of the circled portion of  FIG. 21  showing a further alternative embodiment whereby a flexible anti-pinch wiper element  80  suitably of a thin plastics material is connected to, or integrally formed with, the end of the inner tubular member  4 . The flexible anti-pinch element  80  is disposed such it abuts against the outer surface of the end of the obturator  72  and prevents tissue from being trapped or pinched between the outer surface of the end of the obturator  72  and the inner surface of the inner tubular member  4 . 
     While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.