Patent Publication Number: US-2021177424-A1

Title: Rubber band ligation system for treatment of hemorrhoids

Description:
BACKGROUND OF THE INVENTION 
     This application is a continuation of application Ser. No. 16/125,561, filed Sep. 7, 2018, which claims priority from provisional application Ser. No. 62/566,255, filed Sep. 29, 2017, the entire contents of which are incorporated herein by reference. 
     1. Field of the Invention 
     This application relates to a system and method for treatment of hemorrhoids. 
     2. Background 
     Internal hemorrhoids are normal, asymptomatic rectal vascular tissue. There are typically three or more internal hemorrhoids, which play a role in reducing the anal trauma during defecation and aiding in gas and stool continence. When hemorrhoids, however, enlarge and/or their surface becomes fragile (due to inflammation, infection, or other factors), they may bleed and/or prolapse outside of the anus, which may cause discomfort, pain, anemia, and other disturbing symptoms. 
     One of the common treatment methods of symptomatic hemorrhoids is referred to as “rubber band ligation” which involves strangulation of the hemorrhoid itself and/or strangulation of its superior blood supply by a special elastic rubber ring (band). The rubber band is placed onto the target tissue using a rubber band ligator in the painless area of the anal canal, which is located anatomically proximal of (“above”) the so-called dentate line. The dentate line is a visible anatomical line separating the sensitive mucosa (located distally to the dentate line) from the non-sensitive (or less sensitive) mucosa (located proximally to the dentate line). In the following few days after the rubber band placement, the tissue strangulated by the rubber band becomes necrotic and falls off leaving a corresponding tissue defect, which then heals over the following weeks. If performed properly, this technique leads to the decreased blood supply to the internal hemorrhoid and/or reduction of its size, resulting in improvement of the associated hemorrhoidal symptoms. 
     Although, overall, the rubber band ligation technique for the treatment of symptomatic internal hemorrhoids is considered fairly straightforward among experts, there are a number of technical and anatomical challenges and nuances which challenge an acquisition of the technical mastery. First, proper placement of the rubber band is critical. If the rubber band is placed too close to the dentate line (either distally or proximally) or too close to the underlying rectal muscle, it may lead to undesirable side effects such as severe pain, tenesmus, and or fainting, and can even in some instances lead to severe complications such as rectal perforation, infection, and/or severe bleeding. To avoid or minimize complications of the rubber band ligation procedure, the rubber band should be placed 2-2.5 cm proximally to the visualized dentate line in the non-sensitive area without any involvement of the underlying rectal muscle. 
     In addition, the rubber band ligation technique requires an assistant which thereby requires coordination. That is, the technique requires an accurate and well-controlled release of the rubber band by the operator in the restricted field with limited view while orchestrating this important maneuver with the assistant&#39;s movements. 
     One of the main technical challenges for an operator during the rubber band ligation technique is related to the need, while holding an anoscope, to pull on the target tissue with either forceps or the suction tip and then, when “just the right amount” of the target tissue appears to be engaged, to release the rubber band onto the base of the pulled tissue. These maneuvers require coordinated manipulations of both hands of the operator and possibly an assistant holding the anoscope. In addition, the view of the target area can be obscured by the instruments and the operator&#39;s own hands, further increasing the challenge of the procedure. 
     While special hemorroidal forceps can provide the most accurate tissue manipulation for application of elastic bands, the forceps require a fairly advanced, expert dexterity. As an alternative, tissue suction can be utilized, however, it requires dedicated suction equipment, which in turn requires access to an electrical source, the need for single use components, and costly professional support and maintenance. Further, the amount of the suctioned tissue may need to vary from case to case, and the suction provided by the typical suction equipment is not sufficiently gauged to address this variable need. There is also no ability in the typical suction equipment to “slightly release” the suctioned tissue. This frequently leads to the excessive tissue suction or repetitive repositioning of the suction tip until “just the right amount” of the target tissue is engaged for rubber banding. Thus, in prior techniques, the operator cannot fully control the amount of tissue suctioned. 
     In current procedures, an anoscope is inserted through the anal canal and instruments for treating the hemorrhoids are inserted through a channel of the anoscope to access the target hemorrhoidal tissue. However, a current problem includes a lack of technology for organizing and stabilizing the instruments within the anoscope. Also, in current instrumentation, the instruments often obstruct the clinician&#39;s view as the clinician tries to view the tissue through the anoscope channel. Not only can current instruments block the surgeon&#39;s direct view but their stabilization relies on the clinician holding the instrument position during manipulation of the instrument. Holding the instrument in position becomes more challenging as components of the instrument are moved in an axial direction. If the axial position is not maintained and the instrument moves during the procedure, its distance from the dentate line will change which results in the risks enumerated above. Thus, a clinician would like to have a view of the working space that is the least obstructed as well as a system that can better ensure the desired position of the instrument is maintained during the procedure. 
     Therefore, there is a need for improvements to the rubber band ligation device and method, which would facilitate the accurate rubber band placement by an operator without requiring advanced manual skills. In addition, it would be further beneficial to eliminate the need for an assistant during the procedure which would not only reduce the cost of the procedure but avoid the risk of non-coordination of the operator and assistant. Moreover, there is a need to improve tissue manipulation as well as a need to improve stabilization of the instruments and visibility of the target area during the procedure. 
     SUMMARY OF THE INVENTION 
     The present invention overcomes the deficiencies and disadvantages of the prior art. The present invention advantageously provides a system for treating hemorrhoid tissue which provides a stabilizing platform for treatment devices such as ligating instruments. The systems disclosed herein achieve such stabilization with minimizing obstruction of visibility. The systems disclosed herein also simplify the procedure. Advantages of the systems can be appreciated by the detailed description herein. 
     In one aspect, the present invention provides a system for treatment of hemorrhoids comprising an anoscope having a first channel extending along a longitudinal axis and a second channel positioned at an angle to the first channel. An elastic band ligation device is insertable into the second channel and carries an elastic band and has an advancer movable in a distal direction to dislodge the elastic band. 
     In some embodiments, an obturator is removably insertable into the first channel to aid insertion of the anoscope into the rectum. 
     In some embodiments, the elastic band ligation device comprises a plunger movable in a proximal direction within a tube of the device to effect suctioning of target tissue. The elastic band in some embodiments is positioned on an external surface of the device and the elastic band ligation device can include a tube and the advancer can be positioned external and concentric with the tube. 
     The system can include a first stop on a wall of the anoscope to restrict distal movement of the ligation device within the second channel and/or a second stop on the anoscope to restrict proximal movement of the ligation device in the second channel. In some embodiments, rotation of the ligation device relative to the anoscope in a first direction enables the second stop to limit proximal movement. In some embodiments, rotation of the ligation device relative to the anoscope in a first direction enables engagement with a portion of the internal wall to limit proximal movement of the ligating device. 
     The anoscope can have a marker to indicate a distance from a dentate line of a patient. 
     In some embodiments, the second channel has a longitudinally extending opening facing inferiorly; in other embodiments the second channel has a longitudinally extending channel facing laterally. In some embodiments, the second channel has fenestrations which can provide discrete spaced apart channel sections. 
     In accordance with another aspect of the present invention, a system for treatment of hemorrhoids is provided comprising an anoscope having a first channel extending along a longitudinal axis and a second channel positioned at an angle to the first channel, the second channel intersecting the first channel so a distal opening of the second channel is in communication with the first channel. An elastic band ligation device is insertable into the second channel, the elastic band ligation device including a first tube and a tissue holder. The first tube is movable to advance and dislodge an elastic band from the ligation device onto target tissue. The second channel stabilizes the ligation device and restricts lateral movement while enabling longitudinal movement within the second channel and the second channel enables access to the target tissue at an angle to a longitudinal axis of the first channel. In some embodiments, the first tube is an outer tube movable with respect to a second tube inside the first tube. 
     In some embodiments, the tissue holder comprises a suction device. The suction device can include a plunger having a transverse distal plate wherein proximal movement of the plunger pulls the target tissue proximally as the outer tube engages the target tissue. In some embodiments, a locking device is provided which includes an engagement structure on the ligation device engagable with engagement structure of the anoscope to restrict axial movement of the ligation device within the anoscope. In some embodiments, engagement structure on the ligation device and anoscope restrict rotational movement of the ligating device within the anoscope. 
     In accordance with another aspect of the present invention, a system for stabilizing an instrument during a hemorrhoid treatment procedure is provided comprising an anoscope having a first channel extending along a longitudinal axis to provide direct visualization to a clinician through a length of the first channel and a second channel positioned at an angle to a longitudinal axis of the first channel to direct instrumentation inserted through the second channel at an angle to a distal end of the first channel to reduce obstruction of direct visualization through the first channel. The second channel further has an engagement structure engageable with an instrument inserted therethrough to restrict axial movement of the instrument to thereby maintain the axial position of the instrument with respect to a dentate line of a patient. 
     In some embodiments, the second channel includes structure to limit rotation of an instrument within the second channel. In some embodiments, a wall of the second channel is non-continuous to provide openings for visualization of the instrument during insertion through the second channel. 
     In accordance with another aspect of the present invention, an anoscope is provided having an outer wall dimensioned and configured for insertion into the anal canal, the anoscope having a proximal end, a distal end, a first channel and a second channel. The first channel extends longitudinally through the anoscope and has a proximal opening and a distal opening. The second channel is positioned at an angle to a longitudinal axis of the first channel and has a proximal opening and a distal opening, the distal opening of the second channel communicating with the first channel and the second channel dimensioned and configured to receive a treatment device such as a ligation device. 
     In some embodiments, the anoscope includes a stop to limit distal movement and/or limit proximal movement of a ligation device inserted through the second channel. The anoscope can also in some embodiments limit rotational movement of a ligation device positioned in the second channel. 
     In some embodiments, the second channel is on a first side of the anoscope and a distal end of the anoscope forms a window on a second side, wherein a distal edge on the first side is distal of an opposing edge of the anoscope on the second side. In some embodiments, the first and second channels share a common wall. In some embodiments, the second channel has a wall having a plurality of fenestrations to provide a series of spaced discrete longitudinally aligned channels. In some embodiments, the second channel includes a longitudinally extending slot to enable lateral insertion of the ligation device into the second channel. 
     In accordance with another aspect of the present invention, an elastic band ligation device is provided comprising a first tube, a plunger positioned within the first tube, and a second tube positioned over the first tube. The first tube is configured to hold an elastic band in tension, wherein the plunger is retractable to suction hemorrhoid tissue and pull hemorrhoid tissue proximally, and the second tube is advanceable to advance the elastic band from the first tube onto the target tissue, 
     The device in some embodiments includes an engagement member for interacting with an engagement surface on an anoscope through which the device is insertable to restrict movement of the device within the anoscope. The device can include a marker for indicating a distance from a dentate line of a patient. 
     In some embodiments, the second tube has a distal edge which contacts the tensioned elastic band to advance it from the first tube. The plunger in some embodiments has a transverse plate at a distal end to engage the hemorrhoid tissue. 
     In accordance with another aspect of the present invention, a method for applying an elastic band to hemorrhoidal tissue is provided comprising:
         a) providing an anoscope having a first longitudinal channel and a second channel extending at an angle to the first channel;   b) inserting the anoscope through the anal canal adjacent hemorrhoid tissue and anatomically proximal of a dentate line of a patient;   c) inserting a ligating device through the second channel of the anoscope; and   d) advancing the elastic band from the ligating device onto the hemorrhoid tissue.       

     In some embodiments, the step of advancing the elastic band comprises the step of advancing an outer tube of the ligating device in contact with the elastic band. 
     In some embodiments, the method includes step of locking the ligating device to the anoscope to restrict axial and/or rotational movement of the ligating device within the anoscope. In some embodiments, the ligating device is rotatable with respect to the anoscope to engage the locking device to restrict axial movement. 
     In some embodiments, the method further comprises the step of retracting an inner member of the ligating device to suction the hemorrhoid tissue and retract the hemorrhoid tissue into the ligating device. The step of advancing the elastic band is preferably performed subsequent to the step of retracting the inner member to suction the hemorrhoid tissue. 
     In some embodiments, the step of inserting the ligating device includes advancing the device through the second channel until it contacts a stop of the anoscope. 
     In some embodiments, the method includes the step of visualizing the ligating device though an opening in the second channel as it is advanced through the second channel. In some embodiments, the step of inserting the ligating device through the second channel includes inserting the ligating device through a proximal opening in the second channel; in other embodiments, the step of inserting the ligating device through the second channel includes inserting the ligating device laterally through a longitudinally extending opening in the second channel. 
     In some embodiments, the anoscope and second channel are configured so that when the anoscope is inserted so a distal edge is at the dentate line, a tip of the ligating device inserted through the second channel to contact the target tissue will be positioned about 2 cm to about 2.5 cm from the distal edge of the anoscope and the dentate line of the patient. In some embodiments, a vertex of an imaginary triangle formed by an intersection of an extended longitudinal axis of the second channel and an extended edge of the anoscope is between about 2 cm and about 2.5 cm from the dentate line of the patient. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       So that those having ordinary skill in the art to which the subject invention appertains will more readily understand how to make and use the surgical apparatus disclosed herein, preferred embodiments thereof will be described in detail hereinbelow with reference to the drawings, wherein: 
         FIG. 1  is a side perspective view of a first embodiment of the anoscope of the present invention; 
         FIG. 2A  is a front perspective view of an alternate embodiment of the anoscope of the present invention showing an internal channel open inferiorly; 
         FIG. 2B  is a front perspective view of an alternate embodiment of the anoscope of the present invention showing an internal channel open laterally; 
         FIG. 2C  is a front perspective view of another alternate embodiment of the anoscope of the present invention having a closed continuous channel; 
         FIG. 3A  is a cross-sectional view showing an obturator positioned within the main channel of the anoscope of  FIG. 1  to aid insertion through the anal canal to access the target hemorrhoidal tissue; 
         FIG. 3B  is a cross-sectional view similar to  FIG. 3A  showing the ligation device of the present invention inserted through the channel of the anoscope of  FIG. 1  (the obturator has been removed); 
         FIG. 3C  is a cross-sectional view showing the ligation device of the present invention inserted through the channel of the anoscope of  FIG. 2C  (the obturator has been removed); 
         FIG. 3D  is a cross-sectional view showing the ligation device of the present invention inserted through the channel of the anoscope of  FIG. 2A  (the obturator has been removed); 
         FIG. 4  is a cross-sectional view similar to  FIG. 3B  showing the ligation device of the present invention fully inserted through the anoscope; 
         FIG. 5  is a close-up view of the area of detail identified in  FIG. 4  showing the ligation device inserted through the channel of the anoscope of  FIG. 2A  prior to engagement with the stop/lockout; 
         FIG. 6  is a view similar to  FIG. 5  showing the ligation device further inserted through the channel to engage the distal stop and align with the radial slot, the arrow indicating the rotational movement of the ligation device; 
         FIG. 7  is a view similar to  FIG. 6  showing the ligation device rotated within the channel to engage the proximal stop and interlock with the anoscope to restrict axial movement; 
         FIG. 8A  is a view similar to  FIG. 5  showing the ligation device inserted through the channel of the anoscope of  FIG. 2C  prior to engagement with the stop/lockout; 
         FIG. 8B  is a view similar to  FIG. 8A  showing the outer tube with a window; 
         FIG. 9  is a cross-sectional view showing the ligation device extending through the anoscope of  FIG. 1  and showing the inner tube and plunger plate engaged with the hemorrhoid tissue; 
         FIG. 10  is a view similar to  FIG. 9  showing the plunger retracted to suction target tissue within the inner tube; 
         FIG. 11  is a view similar to  FIG. 10  showing the plunger slightly advanced to release some of the suctioned tissue; 
         FIG. 12  is a view similar to  FIG. 10  showing the outer tube advanced to advance the elastic band around the target tissue; 
         FIG. 13  is a view similar to  FIG. 12  showing the plunger in the initial position and the elastic band placed around the target tissue; 
         FIG. 14  is a view similar to  FIG. 13  showing the ligation device being withdrawn from the anoscope; 
         FIG. 15  is a view similar to  FIG. 14  showing the anoscope being withdrawn from the rectum; 
         FIGS. 16 and 17  are perspective views showing the ligation device inserted laterally into the internal channel of the anoscope of  FIG. 2A ; 
         FIG. 18  is a perspective view showing the ligation device inserted longitudinally through the proximal opening of the internal channel of the anoscope of  FIG. 2A   
         FIG. 19  is a side perspective view of an alternate embodiment of the ligation device of the present invention having a bent distal tip; 
         FIG. 20  is a flow chart depicting the steps of one embodiment of the method of the present invention; 
         FIG. 21  is a side perspective view of an anoscope of another alternate embodiment of the present invention; 
         FIG. 22A  is a side perspective view of an anoscope of another alternate embodiment of the present invention; and 
         FIG. 22B  is view similar to  FIG. 22A  showing a ligation device inserted through the channel with the tip a fixed distance proximal of the dentate line. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The systems and methods of the present invention simplify the rubber band ligation procedure and advantageously eliminate the need for an assistant. The systems of the present invention also improve the organization and stability of the instrumentation to enable wider physician use of the system. Further, the systems of the present invention improve the clinician&#39;s visibility of the target tissue. The systems disclosed herein achieve the foregoing by providing a) an anoscope with a dedicated channel for a ligating device or other instruments (devices); and b) a ligating device (instrument) insertable though the dedicated channel. The ligating device (also referred to herein as the ligation device or ligator) can in some embodiments in and of itself suction the target hemorrhoidal tissue and apply an elastic band to the hemorrhoidal tissue. The ligating device can also in some embodiments lock to the anoscope, thereby freeing a hand of the operator or assistant which would otherwise have to hold the components and also ensuring the critical positioning of the ligating device relative to the dentate line is maintained during the procedure. The tissue suctioning and holding capabilities of the ligating device of these embodiments also improve tissue manipulation. The features of the anoscope and ligating device of the present invention are discussed in detail below, along with the method of use. 
     Thus, the technology taught herein provides one or more of 1) an organization of the hemorrhoid treatment instrument(s), such as a ligating device, e.g., a rubber band ligator, to maximize stability and maneuverability and visualization of the hemorrhoidal tissue; 2) interlocking components to restrict movement of the hemorrhoid treatment instrument to free a hand of the clinician and to maintain positioning of the instrument, especially with respect to the sensitive dentate line; 3) simplification of the system to better ensure consistent clinical results so the procedure is not dependent on the skills of the clinician and that the system is available to a wider range of clinicians to utilize; and 4) minimization of instrumentation utilized for treatment of hemorrhoids. It should be appreciated that having such improvements reduces the technical complexity and increases the efficacy and safety of otherwise more complex hemorrhoid tissue treatment procedures. 
     It should be appreciated that the present invention provides an anoscope, a ligating device and/or a system comprising an anoscope and a ligating device. However, it is also contemplated that a different ligating device or other instrumentation can be used with the anoscope of the present invention, i.e., inserted through the dedicated channel of the anoscope. It is also contemplated that the ligating device (ligator) of the present invention can be used with anoscopes other than those of the present invention disclosed herein. Thus, various embodiments of the anoscopes of the present invention will be discussed initially, followed by a discussion of the ligation instrument of the present invention and then followed by a description of the method of use. 
     Turning first to the anoscope, several embodiments of the anoscope are disclosed herein. The commonality of the anoscopes is the feature of a channel angled with respect to the longitudinal axis of the main channel of the anoscope. The channels can be of various lengths, of various configurations and can have slots at various locations. These different embodiments are discussed in detail below. 
     With regard to the anoscopes and ligating devices disclosed herein, the proximal portion is considered the portion or region closer to the user and the distal portion is considered the portion or region further from the user. However, when referring to the anatomy, e.g., the anal canal and the hemorrhoidal tissue, the proximal portion is the portion or region closer to the head or heart of the patient and the distal portion is the portion or region further from the head or heart of the patient. Thus, when discussing the anatomy, the distal end of the ligating device is placed proximal (further inwardly or “above”) the dentate line of the patient. To help understanding, as used herein when referring to the anatomy, “anatomically distally/anatomically proximally” will be used to differentiate from distal/proximal of the instruments and anoscopes. 
     Referring now in detail to the drawings wherein like reference numerals identify similar or like components,  FIG. 1  illustrates one embodiment of the anoscope (also referred to as a cannula) of the present invention, shown in cross-section in  FIG. 3A . The anoscope is designated generally by reference numeral  10  and includes a proximal portion  12  and a distal portion  14 , the wall of the anoscope tapering toward the distal portion  14 . 
     A proximal flange  16  of anoscope  10  provides a wider rim that prevents insertion of anoscope  10  fully into the anal canal and facilitates gripping by the clinician. The anoscope  10  includes a window  18  at the distal portion  14 , the window  18  providing access to the target hemorrhoid tissue for the ligating device extending through the anoscope as described below. As shown, the distal end of anoscope  10  has a distal edge  20  and a distal edge  22  on opposing sides of a longitudinal axis of the anoscope, the distal edge  20  spaced axially proximally of the distal edge  22 . Stated another way, the distal portion  14  of the anoscope  10  is angled so that a distal edge  20  of the wall  31  adjacent the window  18  is proximal of the distal edge  22  of the wall  33  opposite the window  18 . The distal end has a curved contour as shown. 
     The anoscope  10  has a channel (also referred to herein as a lumen)  26  dimensioned and configured to receive an obturator such as obturator  70  of  FIG. 3A . The channel  26  extends along a longitudinal axis of the anoscope  10  and can be considered the main channel (lumen) of the anoscope. In the illustrated embodiment, channel  26  has a transverse cross-section varying in diameter and shape along its length, however, different shaped channels and different shaped cross-sections, e.g., circular, oval, asymmetric, etc. are contemplated and can be uniform or change (non-uniform) along the length. Anoscope  10  also includes an angled channel (also referred to herein as a lumen)  28 . Channel  28  forms an internal channel for receiving an instrument (device), i.e., for insertion of the ligating device described below or other hemorrhoid treatment devices, and is therefore also referred to herein as instrument channel. In the illustrated embodiment, channel  28  is cylindrical with a circular transverse cross-section, however, different shaped channels and different shaped cross-sections, e.g., oval, are also contemplated. Instrument channel  28  is preferably smaller in diameter than main channel  26 . It is also preferably shorter in length. 
     As shown in  FIG. 3A , channel  28  forms an acute angle with channel  26  and has a proximal opening  30  and a distal opening  32 , the distal opening  32  communicating with channel  26  as it opens into channel  26  as shown for example in  FIGS. 3A and 4 . That is, channel  28  intersects channel  26  so an instrument inserted through channel  28  can extend into channel  26  to window  18  to access tissue through window  18 . As discussed above and shown in the cross sectional views, wall  33  of anoscope  10  terminates at edge  22  distally of window  18  and opposing internal wall  31  terminates at edge  20  proximally of inner wall  33 . Internal wall  35  of channel  28  terminates at edge  35   a,  preferably in an intermediate region of the anoscope  10 . 
     The internal wall of the instrument channel can be continuous along its length as shown in the alternate embodiment of  FIGS. 2C and 3C . In this embodiment, a solid wall  44  forms the perimeter (circumference) of the instrument channel  42  of anoscope  40 . The channel  42  can be of circular transverse cross-section, however, different shaped channels and different shaped cross-sections, e.g., oval, are also contemplated The anoscope  40  is otherwise identical to anoscope  10  and therefore for brevity will not be discussed in further detail since the structure and function of anoscope  10  is fully applicable to anoscope  40 , i.e., the flange  45 , main channel  46 , window  48 , etc. 
     Returning to the embodiment shown in  FIGS. 1 and 3A , the internal wall  35  of channel  28 , i.e., the wall facing the longitudinal axis of the channel  26 , is a broken wall wherein the internal wall  35  has one or more gaps or fenestrations (openings)  37 . This can be formed by forming gaps or openings in one or more regions of the wall  35 , extending radially around a partial circumference of the wall of the channel  28 . Alternatively, two or more shorter discrete channels can be provided, spaced apart axially, thereby providing an instrument channel with a non-continuous wall due to the space between the separated channels. Thus, instead of one or more partial circumferential fenestrations along a length, a full 360 degree gap(s) can be provided. This non-continuous wall (formed by fenestrations or separated channels), if utilized instead of a continuous wall, has the advantage of providing a relatively longer channel while reducing the amount of material as compared to if a long continuous channel wall is utilized. It could also simplify manufacture. Additionally, the gaps/openings in the wall enable the clinician to visualize the passage of the instrument through the instrument channel  28  as the clinician looks through the main channel  26  of the anoscope  10 . 
     In the illustrated embodiment, the proximal opening  30  of channel  28  is within channel  26 , just distal of flange  16 , however, in alternate embodiments, the proximal opening  30  can be, i.e., the angled channel  28  can begin, within the flange  16  so it is more proximal than that shown in  FIG. 3A  or can begin at the proximal opening of the flange  16 . Alternatively, the angled channel  28  can have a proximal opening distal of the position of  FIG. 3A , e.g., distal of the distal end of the region of the flange  16 . The angled inner wall  35  of the channel  28  preferably terminates in a mid region of the anoscope, leaving enough space so as not to interfere with insertion of obturator  70  as shown in  FIG. 3A  nor interfere with the clinician&#39;s naked eye viewing through channel  28 . Note the wall  35  forming the wall of channel  28  can be of different lengths than that shown as long as it is of sufficient length to support an instrument and not excessive length so as to interfere with the obturator or obstruct the clinician&#39;s view through channel  26  of the anoscope. As mentioned above, the internal wall  35  can be a solid wall or alternatively can be a fully broken wall or a wall with fenestrations. Also note that the wall of the instrument channel  28  can be formed in part by the wall of the anoscope so that channel  28  and anoscope  10  share a common wall. 
     In the embodiment of  FIG. 1 , the outer wall  33  angles to intermediate region, i.e., angles inwardly toward the longitudinal axis of the anoscope, and then has a reduced angle toward the distal end while the opposing wall  31  (the wall of the window  18 ) is substantially linear, i.e., substantially aligned with the longitudinal axis. Alternatively, wall  31  can also be angled, e.g., angled inwardly toward the longitudinal axis. Tapers other than those illustrated are also contemplated. 
       FIGS. 2A and 2B  illustrate alternate embodiments of the instrument channel of the anoscope of the present invention. Except for the instrument channels, the anoscope of 
       FIG. 2A  and  FIG. 2B  are identical to anoscope  10  of  FIG. 1 . Therefore the discussion of the anoscope (other than the instrument channels) is not repeated herein and only the instrument channels are discussed in detail since the other features and functions of anoscope  10 , e.g., the flange, main channel, window, etc., are fully applicable to the anoscopes of  FIGS. 2A and 2B . 
     In  FIG. 2A , the anoscope  50  has a proximal flange  52 , a main channel  53  to removably receive an obturator, e.g., obturator  70 , and an internal instrument channel  54 . Instrument channel  54  has a partial wall segment as it opens inferiorly along its length. That is, channel  54  has a longitudinally extending elongated opening  56  extending along its length, with the elongated opening  56  facing the main channel  53  of the anoscope  50 . Stated another way, the channel  54  is C or U-shaped as the circumference of its wall extends for less than 360 degrees. Channel  54  has a proximal opening  55  and a distal opening  57  (see  FIG. 3D  showing a cross-sectional view of the anoscope of  FIG. 2A ). As illustrated, the channel  54  is relatively short, extending for a minimal distance within the anoscope and terminating at distal end  51  a short distance from the flange  52 . However, it should be appreciated that the channel  54  can be of a longer length such as the length of channel  28  of  FIG. 3A . 
     The longitudinal opening  56  enables an instrument, e.g., a ligating instrument, to be loaded laterally into the channel  54 . Such lateral loading is shown for example in  FIGS. 16 and 17 . This lateral insertion can be advantageous for example if the instrument is dimensioned so that it has regions of varying diameter which could not fit through proximal opening  55 . In other words, if an instrument, such as a ligating instrument, has for example a distal region which has a diameter greater than a diameter of the channel  54 , e.g., the diameter of the proximal opening  55 , the instrument could not be inserted longitudinally through the opening  55  because it would not fit. However, it could be loaded into the channel  54  by inserting a smaller diameter portion laterally through the longitudinal opening  56  as shown. Clearly, if the instruments are of a small enough dimension, rather than lateral insertion, if desired, they can alternatively be inserted into the channel  54  through proximal opening  55  such as shown in  FIG. 18 . Thus, channel  54  allows for both proximal (longitudinal) and lateral insertion of the instrument therein, which can be dependent on the size of the instrument utilized. Additionally, it in certain embodiments, the channel  54  can be made of a material that is flexible so that the instrument could have a slightly larger diameter which flexes the channel  54  (walls of the channel) as it is inserted laterally therein. That is, the wall  58  of the instrument channel can be composed of a material that provides sufficient flexibility to expand when the instrument is inserted laterally (and also longitudinally). This would enable larger instruments to be laterally inserted therein as the instrument would flex the wall of the channel  54  to widen the longitudinal opening  56  for insertion, and then after insertion the wall would flex back toward a more closed position. Sufficient flexibility could also allow a larger diameter instrument to be inserted longitudinally since the elongated opening increases the flexibility of the instrument channel. 
     The shorter channel if utilized provides the advantages enumerated above of less material and improved visualization of the instrument by the clinician as it is being inserted through the channel  54  since minimal part of the instrument is blocked by the wall of the channel. 
     Note in  FIGS. 16 and 17  (and  18 ) the instrument is shown schematically and labeled as instrument A as various types and sizes of instruments, including the ligating instrument of the present disclosure, can be utilized with the anoscope  10   
     An alternate embodiment of the instrument channel is illustrated in  FIG. 2B . In this embodiment, the internal instrument channel  64  of anoscope  60  has an opening  65  along its length which rather than facing inferiorly, faces in another lateral direction. Anoscope  60 , like anoscope  10 , has a proximal flange  62  and a main channel  63  to removably receive an obturator, e.g., obturator  70 . Instrument channel  64  has a partial wall segment as it opens along its length, facing away from the longitudinal axis of anoscope  60  and toward wall  61  of anoscope  60 . The channel  64  is C or U-shaped as the circumference of its wall extends for less than 360 degrees. Channel  64  has a proximal opening  65  and a distal opening. As illustrated, the channel  64  is longer than channel  54  as it extends further into the anoscope  10 , for example a distance of the instrument channel of  FIG. 3C . Alternatively, it could be relatively short, extending for a minimal distance within the anoscope and terminating at a distal end a short distance from the flange  62  in the same manner as channel  54  of anoscope  50  of  FIGS. 2A and 3D . In either length, the elongated longitudinally extending opening  65  enables an instrument, e.g., a ligating instrument, to be loaded laterally into the channel  64  as in the lateral loading shown in  FIGS. 16 and 17 , however, the approach to the channel  64  would be different since the longitudinal opening is at a different region than the opening  56  in channel  54 . Loading longitudinally through the proximal opening  65  as in  FIG. 18  is also contemplated if the instrument size permits. The lateral insertion can be advantageous for the reasons described above. Advantages of a shorter channel are also described above. However, it should be appreciated that the longer channel has the advantage of improved stability of the instrument positioned therein because the instrument is retained along a longer length. As with channel  54 , in certain embodiments, the channel  64  can be made of a material that is flexible so that the instrument could have a slightly larger diameter which flexes the channel  64  as it is inserted laterally therein or even if inserted longitudinally through the proximal opening  65 , and then after insertion the wall would flex back toward a more closed position. 
       FIGS. 2A and 2B  show examples of positioning of the longitudinal opening with respect to the main channel of the endoscope. It should be appreciated, that the openings could be located in other positions. Also, the openings can be of larger or smaller size. For example, the channel can have an opening in the form of a narrow slit extending along its length. 
     Thus, the asymmetric anoscope  10  of the present invention, in the embodiments described herein, has a dedicated channel on the wall opposite to the target tissue to receive an instrument (device) such as the rubber band ligator (also referred to herein as an elastic band ligator) to form a guide section. The channel can be in the shape of a cylinder (or alternatively other configurations), which can have a separate wall or share the wall with the anoscope and/or have a continuous or non-continuous, e.g., a fenestrated wall. A single channel forming the guide section can be provided or alternatively two or more axial spaced channels can provide guiding sections for the instrument, e.g., the ligator, through the anoscope. The channel can also have a longitudinal slot or opening along its length, providing a cross-sectional configuration of a C or U shape. 
     The anoscope of any of the embodiments disclosed herein can include a visual marker such as red marker on the exterior and/or interior side wall of the anoscope by the treatment window, although other markers/indicators are also contemplated. Such marker is shown for example in  FIG. 3B  and designated by reference numeral  17 . The marker  17  is located between walls  33  and  31  and the distal edges  22  and  20 . The marker aids the positioning of the anoscope relative to the dentate line. That is, the anoscopes disclosed herein are positioned so that the dentate line of the patient is visible just anatomically proximal to the proximal edge of the treatment window of the anoscope—the target point for tissue ligation. Therefore, the anoscope is positioned so the marker  17  is aligned with the target tissue and approximately 2 cm from the dentate line. This means the anoscope is inserted so the marker  17  is approximately 7 cm from the anal orifice. 
     The anoscope of any of the embodiments disclosed herein can include a structure to engage, e.g., interlock, with the ligating instrument to restrict movement of the ligating instrument with respect to the anoscope. Such structure, which is also referred to herein as a locking structure, interlocking structure or a blocking structure, is shown in  FIGS. 5, 6 and 7 . Anoscope  50  is illustrated by way of example to illustrate the locking structure, it being understood that the other anoscopes disclosed herein can also have this locking structure. As shown in  FIG. 5 , anoscope  10  has a slot  58  formed in its wall, the slot  58  having an axial region  58   a  and a radial region  58   b,  forming an L-shape, the radial region being a more distal region. The slot  58  can be located at a proximal end of the anoscope  50 , e.g., just distal of the flange  52  as shown by the designated area of detail of  FIG. 4 . Alternatively, it can be located at other regions of the anoscope, e.g., further distal than the location of  FIG. 4 . 
     Slot  58  has a distal wall  59   a  at the distal end of axial region  58   a  that forms a distal stop for the ligating instrument. Radial region  58   b  has a proximal wall  59   b  forming a proximal stop for the ligating instrument. Radial region  58   b  shares the distal wall  59   a.  The distal stop restricts distal movement of the ligating instrument within the anoscope and the proximal stop restricts proximal movement of the ligating instrument within the anoscope. The ligating instrument  80  has engagement structure  83  extending from an outer surface  81  of its outer wall which can be in the form of a hook-like engagement member. When the ligating instrument  80  is initially inserted into channel  54  of anoscope  50 , engagement structure  83  is received in the narrower axial slot region  58   a  and the ligating instrument  80  cannot rotate in either direction as it is blocked by side walls  59   c  and  59   d  of slot region  58   a.  When the ligating, instrument  80  is advanced, its engagement structure  83  contacts distal wall  59   a.  Thus, distal wall  59   a  restricts (blocks) further distal movement of the ligating instrument  80 . At this point when the distal stop surface (wall  59   a ) is engaged by engagement structure  83  of ligating instrument  80 , the engagement structure  83  of the ligating instrument  80  is aligned with the radial slot region  58   b  as shown in  FIG. 6 . This slot region  58   b  provides room for the ligating instrument  80  to be rotated in the direction of the arrow of  FIG. 6  to the position of  FIG. 7 . In this position of  FIG. 7 , the ligating instrument  80  still cannot be advanced distally due to wall  59   a  and further cannot be retracted proximally due to proximal wall  59   b.  Thus, the distal and proximal walls of the engagement structure  83  abut the respective distal and proximal walls  59   a,    59   b  to prevent axial movement in either direction. This maintains the ligating instrument  80  in its axial position during the procedure, ensuring that its position with respect to the dentate line (and marker on the anoscope if provided) is maintained during the surgical procedure. Note that to remove the instrument after the procedure, the ligating instrument  80  is rotated in the opposite direction of the arrow of  FIG. 6  to re-align the engagement structure  83  of the ligating instrument  80  with the axial slot region  58   a  so it can be withdrawn proximally along the region  58   a.    
     Thus, the anoscope  50  has a channel or slot to receive a raised portion (raised engagement or locking structure) of the ligating instrument, with the channel having a first configuration and a second different configuration, The first configuration restricts rotation of the ligating device within the anoscope during its insertion distally and the second configuration allows slight rotation of the ligating device to enable engagement of the proximal stop to interlock the ligating instrument and anoscope to restrict proximal and distal axial movement of the ligating instrument within the instrument channel. Thus, the ligating device is first stopped by the stopping feature and subsequently locked by the device&#39;s locking feature so the tip of the ligating instrument  80  is placed and fixated at the target tissue (cross of the line corresponding to the device marker and a line corresponding to the middle of the lower wall of the anoscope). Although described above for locking ligating instrument  80 , other instruments can be provided with the engagement structure to provide for locking to the anoscope in the manner described herein. 
     Note during insertion through the axial slot region  58   a,  as noted above, the ligating instrument cannot be rotated. However, when in the radial slot region  58   b,  it can be rotated back into alignment with slot region  58   a.  To limit rotation during the procedure when it is engaged with the radial region  58   b,  the proximal wall  59   b  and/or the distal wall  59   a  in the region of slot region  58   b  can be provided with one or more detents or other structure so that a predetermined force is required to rotate the ligating instrument and engagement structure from the position of  FIG. 7  back to the position of  FIG. 6 . In this manner, rotational movement of the ligating instrument can be restricted unless the clinician rotates the ligating instrument with a sufficient force to override the detent(s) to align with axial slot region  58   a.  With this provision, the ligating instrument would be locked (blocked) from axial and rotational movement during use. 
     It should also be appreciated that due to the engagement structure/slot arrangement in this embodiment, the ligating instrument can only be inserted in an orientation where the engagement structure is aligned with the slot. If not aligned, the instrument will not fit within the channel. To facilitate such orientation, one or more markers can be provided on the anoscope to aid alignment of the ligating instrument with the slotted region of the anoscope. 
       FIGS. 5-7  shown the slot regions  58   a,    58   b  formed in the anoscope  50  of  FIG. 3A . By way of another example,  FIG. 8A  shows such slotted regions used with the anoscope  40  of  FIG. 2C  having a closed channel  42 . The slot regions  48   a,    48   b  of  FIG. 8A  are identical to the slot regions  58   a,    58   b,  respectively, of  FIGS. 5-7  and therefore further discussion is not warranted since the interaction of the ligating instrument  80  with the slot regions  58   a,    58   b  and distal and proximal walls  59   a,    59   b  is fully applicable to the slot regions  48   a,    48   b  and distal and proximal walls  49   a,    49   b  of anoscope  40 . The interaction with anoscope  40  is shown to illustrate by way of example that the interlocking structure can be utilized with any of the instrument channels disclosed herein. 
       FIGS. 5-8A  illustrate one type of stop and locking mechanism. It is also contemplated that other mechanisms can be provided to restrict distal advancement of the instrument through the channel of the anoscope and/or lock axial movement in both proximal and distal directions and/or restrict rotation of the instrument with respect to the anoscope. 
     Turning now to the rubber (elastic) band ligation device (also referred to herein as the ligator or ligating device or ligating instrument) of the present invention, and with initial reference to  FIG. 9  which shows the ligating device already inserted through the anoscope, ligating device (instrument)  80  has a distal portion  82  for positioning within the body of the patient and a proximal portion  84  extending outside the body for manipulation by the operator (clinician). Ligating device  80  includes an inner or middle tube-like structure  86  with a lumen (channel)  88 , a plunger  90  slidable within lumen  88  of inner tube  86  and an outer tube  92  with a lumen (channel) to receive the inner tube  86 . The inner and outer tubes  86 ,  92  are relatively movable. The plunger  90  and inner tube  86  are also relatively movable. An elastic (rubber) band  94  is carried, e.g., supported in tension, by the inner tube  86  and is positioned on an exterior wall  88   a  of the inner tube  86  for deployment therefrom by distal advancement of the outer tube  92  which pushes the elastic band  94  off wall  88   a.  The inner tube  86  has a distal end  87  and proximal end  89 . The distal end is  87  substantially round or oval, although other configurations are contemplated, and engages the target tissue to work with the plunger  90  for suctioning tissue. The proximal end  89  extends proximally of the anoscope. The wall of inner tube  86  and outer tube  92  may be whole or incomplete, e.g., have fenestrations, to reduce the amount of material and to enable viewing of the plunger  90  sliding within the lumen  88  of the inner tube  86 . 
     The proximal end  89  of the inner tube  86  can extend proximally of the outer tube  92  or the proximal end alternatively can terminate distally of the proximal end of the outer tube  92 . The inner tube  86  can contain the projecting engagement structure  83  which releasably engages the stopping and locking features at a proximal end of the anoscope. A portion of the outer tube  92  can be cut away to expose the engagement structure  83  of inner tube  86  so that the engagement structure  83  can interact with the slotted regions (e.g., regions  58   a,    58   b ) of the anoscope to provide the aforedescribed axial and rotational restrictions. The outer tube  92  can alternatively have a circumference of less than  360  degrees, e.g., be C or U-shaped along its length, or partial length, to expose the engagement structure  83  or engagement with the slotted regions  58   a  and  58   b.    FIG. 8B  illustrates by way of example an embodiment of the outer tube  92 ′ having a window or cutout  93  formed therein aligned with the engagement structure  83  of inner tube  86 . The window  93  exposes the engagement structure  83 . The window  93  allows for sufficient longitudinal (axial) movement of the outer tube  92 ′ with respect to the inner tube  86  to dislodge a rubber band from the ligating instrument  80 . The outer tube  92 ′ with window  93  can be utilized with any of the embodiments of the ligating instrument and anoscope disclosed herein and is shown in conjunction with the anoscope  40  of  FIG. 8A  by way of example. 
     Note in alternate embodiments, the projecting engagement structure can be located on the outer tube  92  and the inner tube  86  and outer tube  92  would be interlocked so that stopping and locking of the outer tube  92  to prevent axial and/or rotational movement, would likewise result in stopping and locking the inner tube  86  as well. 
     Referring back to  FIG. 9 , the plunger  90  includes a proximal handle  96  for gripping by the user, an elongated rod  97  extending distally from the handle  96 , and a transversely (horizontally) extending plate  98  connected at the distal end of rod  97 . The handle  96  extends proximally of the inner tube  86  and outside the patient for access by the clinician. The rod  97  can be connected to an upper (proximal) surface of the plate  98 , and can in some embodiments be connected to a central region of the plate  98 . The plate  98  can be round, oval or other configurations. The plunger  90  provides for suctioning of the tissue into the inner tube  86  for subsequent application of the elastic band. 
     One of the main technical challenges for an operator during the rubber band ligation technique is related to the need, while holding the anoscope, to pull on the target tissue and when “just the right amount” of the target tissue appears to be engaged, to release the rubber band onto the base of the pulled tissue. These maneuvers require coordinated manipulations of both hands of the operator and possibly an assistant holding the anoscope. In addition, the view of the target area can be obscured by the instruments and the operator&#39;s own hands, further challenging the procedure. Also, the amount of the suctioned tissue may need to vary from case to case and in certain instances, e.g., if more than the desired amount of tissue is suctioned into the inner tube, the need might exist to “slightly release” the suctioned tissue. 
     The plunger  90  slides within the inner (middle) tube-like structure  86 . The plate  98  of the plunger  90  is positioned distally of the inner tube  86 . Such distal positioning can be achieved during use or alternatively, the instrument can be provided so that the plate  98  is always located distally, i.e., during packaging, initial insertion and use. 
     The plunger  90  is actuated by the operator&#39;s hand for the purpose of creating and gauging the suction on the target tissue. By moving the plunger  90  forward (distally) towards the target tissue, the tissue can be engaged. By moving the plunger backward (proximally) while the distal end of the inner (middle) tube  86  is hermetically pressed against the target area, the target tissue is suctioned into the distal end (the target tissue chamber) of the inner tube  86 . The inner tube  86  thus forms a target tissue chamber within its lumen  88  for receipt of the suctioned tissue. If excess tissue is suctioned into the inner tube  86 , the clinician can re-advance the plunger  90  as in  FIG. 11  to release the suction and thereby release some of the tissue. Thus, such distal movement enables the user to release a portion of the suctioned tissue or, if desired, release the entire suctioned tissue from the tissue chamber formed in the inner tube  86 . 
       FIG. 19  illustrates an alternate embodiment of the ligating device of the present invention. The ligating device  80 ′ is identical to ligating device  80  of  FIG. 9  except that it has a bent distal tip  80   a.  The bent tip  80   a  is bent toward the target tissue and in certain applications might facilitate tissue engagement and might improve access and visibility of the target tissue. Device  80 ′ is otherwise identical to device  80  so for brevity is not further discussed since the structure and function of device  80  are fully applicable to device  80 ′. For ease of understanding, the like (corresponding) components of device  80 ′ have been designated with prime reference numerals, e.g., plunger  90 ′, plate  98 ′, inner tube  86 ′, outer tube  92 ′. As with the device  80 , device  80 ′ can include a mechanism (actuator) to advance the inner tube or the inner tube can be accessible to the user at a proximal end extending proximally of the outer tube or through an opening in the outer tube that enables access to the inner tube. 
     The use of the anoscope and ligating device of the present invention will now be described, in conjunction with  FIGS. 3A, 9-15  and the flow chart of  FIG. 20 . Note the discussion of the method of use is described with the use of anoscope  10 , it being understood that the anoscope of the other embodiments disclosed herein could be utilized and would operate in a similar fashion, except for the possible lateral insertion of the ligating instrument into the instrument channel as described above rather than the longitudinal insertion. The ligating device described and illustrated in these Figures is the aforedescribed ligating device  80 . 
     In the first step, the blunt tip obturator  70  is inserted longitudinally into the main channel  26  of the anoscope (cannula)  10  and then the anoscope (cannula)  10  with the blunt tip obturator  70  positioned therein and extending slightly distally of the anoscope  10  are introduced into the rectum of the patient, inserted approximately  7  cm into the rectum (see  FIG. 3A ). The obturator  70  is then removed from the anoscope and the internal hemorrhoid and dentate line are visualized through the proximal opening and channel  26  of the anoscope  10 . The anoscope  10  is positioned so the marker  17  is spaced a predetermined distance from the dentate line, e.g., 2 cm anatomically proximal of the dentate line. Thus, in the illustrated embodiment, the edge  20  adjacent the window  18  of can be positioned at the dentate line (or just proximal of the dentate line) since the marker  17  is positioned 2 cm from the edge  20 . 
     Next, with the position of the anoscope  10  satisfactory (via direct visualization), the ligating device (ligator)  80  is inserted into the angled channel (lumen)  28  of the anoscope ( FIGS. 3B and 9 ) and moved forward towards the marker  17  which provides the identification of the target area. Lateral movement of the ligating device  80  is restricted by wall of the channel  28 . The ligating device  80  is advanced until stopped by the device-stopping feature of  FIGS. 5-7  as the projecting engagement structure  83  of the ligating device  80  contacts the distal wall  59   a  of the slot  58   a  of the anoscope  10 . Note the ligating device  80  is aligned with the channel  28  so that its engagement surface  83  is aligned with slotted region  58   a  so it can slide within the channel  28 . Note the ligating device  80  can be inserted into the channel  28  either longitudinally as in  FIG. 18  or laterally as in  FIG. 17 . When in abutment with the stop (distal wall  59   a ), the tip of the device  80  is in the desired position with respect to the target hemorrhoid tissue T and the dentate line ( FIG. 9 ). After contacting the distal stop, i.e., distal wall  59   a,  the ligating device  80  is rotated ( FIGS. 6-7 ) so the engagement structure  83  moves into radial slot  58   b,  thereby locking the ligating device  80  as proximal and distal axial movement are restrained. In this locked position, the distal end of the ligating device  80  is engaged with the hemorrhoid tissue anatomically proximal of the patient&#39;s dentate line, thereby ensuring the elastic band is not placed too close to the dentate line which can lead to undesirable side effects/complications such as severe pain, tenesmus, fainting, rectal perforation, infection, and/or severe bleeding. With the ligating device  80  fixed to the anoscope  10 , the operator visually confirms the desired target position. 
     Once confirmed, the plunger  90  inside the hollow internal tube  86  is then slowly pulled back as the end of the inner tube  86  presses and seals against the tissue as shown in  FIG. 10 , thereby suctioning the target tissue into the lumen  88  of the inner tube  86  under direct visualization and assuring that the patient is not experiencing any discomfort. After the desired amount of the target tissue is suctioned into the distal chamber within the lumen  88 , the elastic band  94  is ready to be applied. However, prior to elastic band application, if the operator determines that too much tissue has been suctioned into the chamber of the internal tube  88 , the plunger  90  can be advanced distally as shown in  FIG. 11  to release some of the tissue. Note that if it is desired to fully release the tissue to then re-suction the tissue from the beginning, the plunger  90  can be pushed distally to its original position, thereby entirely releasing the suction. Also note that if the operator is satisfied with the amount of tissue suctioned into the chamber of the inner tube  86 , then the step of  FIG. 11  is omitted and the operator proceeds to the elastic rubber band application as in  FIG. 12 . This is illustrated in the flow chart of  FIG. 20  at the decision box inquiring whether excessive tissue has been suctioned. 
     Once the clinician is satisfied with the tissue suctioned within the inner tube  86 , the outer tube (advancer)  92  is advanced distally in the direction of the arrow of  FIG. 12  (as the inner tube  86  remains fixed) to push the elastic rubber band  94  as its distal end contacts (abuts) the elastic rubber band  94  supported on the exterior surface of the inner tube  86 . The outer tube  92  is pushed forward until the elastic band  94  is pushed off (dislodged from) the inner tube  86 . The elastic band  94  is thereby released onto the base of the suctioned tissue as shown in  FIG. 13  to strangulate the target tissue. 
     The ligating device  80  is then withdrawn proximally in the direction of the arrow of  FIG. 14  for removal from the anoscope. After removal of the ligating device  80 , the anoscope is then withdrawn proximally from the rectum in the direction of the arrow of  FIG. 15 . 
     If it is desired to treat another hemorrhoid, and the device  10  carries multiple elastic bands, the anoscope  10  and ligating device  80  are rotated to align the window of the anoscope with the target hemorrhoid tissue, the location of the anoscope  10  and ligating device  80  visualized with respect to the dentate line. Then the plunger  90  is retracted to suction the tissue into the lumen  88  of inner tube  86  followed by advancement of the outer tube  92  to release another elastic band  94  in accordance with the steps of the procedure illustrated in  FIGS. 10-13  and depicted in the flow chart where if an additional hemorrhoid needs to be treated, it loops back to the procedure as shown. If it is desired to treat another hemorrhoid and the ligating device  10  carries only a single elastic band  94 , the ligating device  80 , with the anoscope  10  remaining in position, is withdrawn and another elastic band  94  is loaded onto the exterior surface of the inner tube  86  (The outer tube  92  can be retracted to leave a portion of the exterior surface exposed to provide room for mounting the elastic band  94 ). The ligating device  10  with the newly mounted elastic band  94  is then inserted thorough the anoscope  10 , the tissue suctioned and the outer tube  92  advanced in the manner described above in conjunction with  FIG. 9-13 . The procedure can be repeated until all other internal hemorrhoids (typically a total of three) are treated. 
       FIG. 21-22B  illustrate alternate embodiments of the anoscope utilizing the angle of the second channel itself to ensure positioning of the ligating or other instrument anatomically proximal of the dentate line. More specifically, anoscope  100  of  FIG. 21  has a proximal portion  102  and a distal portion  104 , the wall of the anoscope tapering toward the distal portion  104 . The anoscope  100  terminates at distal edge  105  and distal opening  106 . The anoscope  100  has a channel (lumen)  108  dimensioned and configured to receive an obturator such as obturator  70  of  FIG. 3A . The channel  108 , like channel  26  of anoscope  10  discussed above, extends along a longitudinal axis of the anoscope  100 . In the illustrated embodiment, the channel  108  has a transverse cross-section varying in diameter and shape along its length, however, different shaped channels and different shaped cross-sections, e.g., circular, oval, asymmetric, etc. are contemplated and can uniform or change (non-uniform) along the length. 
     Angled internal instrument channel (lumen)  110  forms a channel for receiving an instrument (device), e.g., the ligating device described herein. Channel  110  is cylindrical with a circular transverse cross-section, however, different shaped channels and different shaped cross-sections, e.g., oval, are also contemplated. Instrument channel  110  is preferably smaller in diameter than main channel  108 . Channel  110  forms an acute angle with channel  108  and has a proximal opening  113  and a distal opening  112  terminating adjacent distal opening  106  of channel  108 . 
     The walls of the anoscope  100  are configured and angled so that in use the target tissue (represented schematically by “X”) is at a vertex of the triangle formed by the side of the anoscope. That is, the vertex V of the triangle is formed at the intersection of a) an imaginary line L extending (extrapolated) from the edge  107  (along the longitudinal axis of the edge) of anoscope  100  and b) the longitudinal axis of the angled channel  110  extended (extrapolated) distal of the distal edge  105  (imaginary line M). Thus, with the walls angled in such a way, the vertex V of the triangle where the target tissue is located is predictably located a fixed distance, e.g., about 2 cm to about 2.5 cm, proximal to the dentate line (represented by “D”) of the patient which is positioned to be visible near the edge  105  of the anoscope  100 . Therefore, a marker need not be utilized since in use, the clinician would insert the anoscope until the distal edge  105  is at the visualized dentate line (visualized with the naked eye as the clinician looks through channel  108 ). In this position, when an instrument is inserted through the angled (second) channel  110 , the tip of the instrument when contacting the target tissue would be about 2 cm to about 2.5 cm anatomically proximal from the dentate line (the distance from V to D). The instrument could be locked to the anoscope in this position utilizing the interlocking structure discussed above. 
     The anoscope  120  of  FIG. 22A  is identical to the anoscope  100  of  FIG. 21  except that angled instrument channel  124  has a slanted or angled distal tip  126  at edge  128 . That is, edge  128  angles proximally to increase visibility by limiting the blocking of the view through the main channel (lumen)  122 . In all other respects, anoscope  120  is identical to anoscope  100  so further discussion is not warranted as the features and use of anoscope  100  described herein are fully applicable to anoscope  120 . The line L (extrapolated from edge  125 ) and vertex V are also shown in  FIG. 22A  to illustrate the predictable positioning of the instrumentation anatomically proximal of the dentate line (the distance from dentate line D to vertex V formed at the intersection of imaginary extrapolated lines L and M which in preferred embodiments is between about 2 cm to about 2.5 cm).  FIG. 22B  shows a ligating instrument, e.g., ligating instrument  80 , inserted through the anoscope  120  to illustrate the distal tip  81  of instrument  80  at the vertex V of the imaginary triangle. Both anoscopes  100  and  120  can include a flange as illustrated as in the other embodiments described herein. 
     Note the channels  110  and  124  can open partially or fully outside/distal to the anoscope  100 . Also, as an alternative to the continuous channel shown, channel  110  or  124  can be non-continuous, have an elongated slot so it is U or C-shaped, etc. as in the various embodiments of the channels discussed above and illustrated in the drawings. Thus, these variations of the angled instrument channel discussed above are applicable to channels  110  and  124  of the anoscope  100  and  120 , respectively. 
     While the above description contains many specifics, those specifics should not be construed as limitations on the scope of the disclosure, but merely as exemplifications of preferred embodiments thereof. For example, those skilled in the art will envision many other possible variations that are within the scope and spirit of the disclosure as defined by the claims appended hereto.