Abstract:
A ligating system having a ligating apparatus configured to attach to a distal end of a scope and to hold a ligating band thereon; an activating cord configured to extend down a working channel of the scope and attach to the ligating apparatus; and a line pulling assembly including: a central body; an attachment mechanism on the central body configured to attach the line pulling assembly to a proximal end of the scope; an access channel through the central body and in communication with the working channel of the scope, the access channel providing an open inlet to the working channel of the scope when the line pulling assembly is attached to the proximal end of the scope; and a winding mechanism attached to the central body, wherein the winding mechanism is configured to pull the activating cord proximally such that the ligating band is removed from the ligating apparatus.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 14/642,503 filed Mar. 9, 2015, titled “LIGATOR AND METHOD OF USE,” now U.S. Pat. No. 9,504,472, which is a continuation of U.S. patent application Ser. No. 13/834,087, filed Mar. 15, 2013, titled “LIGATOR AND METHOD OF USE,” now U.S. Pat. No. 8,974,474, which claims the benefit of U.S. Provisional Patent Application No. 61/701,357, filed Sep. 14, 2012, titled “LIGATOR AND METHOD OF USE,” and U.S. Provisional Patent Application No. 61/707,111, filed Sep. 28, 2012, titled “LIGATOR AND METHOD,” all of which are hereby incorporated by reference in their entirety. 
     
    
     FIELD 
       [0002]    The present disclosure is directed to a ligator apparatus and method, and in one particular embodiment, to an esophageal ligator and method of esophageal ligation. 
       BACKGROUND 
       [0003]    Methods for treatment of varices and general ligation methods have long been known in the art. This has long been so for both for human and non-human tissues. 
         [0004]    Esophageal varices are enlarged esophageal veins. These frequently complicate chronic liver disease. Esophageal varices may rupture and bleed, potentially leading to death. Ligation of the varices can be performed to treat acutely bleeding varices. Ligation can also be performed preventatively to destroy the varices before they start to bleed. During the process of ligation, varices are suctioned into a hollow space of the ligator and bands are released over the tissue to strangulate it. Strangulation leads to death of the tissue and subsequent scarring obliterates the varices. 
         [0005]    The process of ligation can be further effectuated with an endoscope or other device for accessing or penetrating internal aspects of a human, an animal, a fish, or other entity. Endoscopes generally consist of a rigid or flexible tube, a light delivery system, a lens system to transmit images from the object being viewed to the viewer, and an additional channel coupled to the rigid or flexible tube to allow entry of medical instruments. 
         [0006]    Currently used variceal ligators manufactured by Wilson Cook and Boston Scientific, use string with attached beads to pull the rubber band off the cylinder that is attached to the tip of the endoscope. A string is pulled via the working channel of the endoscope and via an inner opened part of the cylinder. The string is then split into two parts (two strings) to which beads are attached. These two strings are then placed over the opposite side of the cylinder. Rubber bands are then placed over the strings in a way that each band is separated by a single bead on both sides of the cylinder. When the string is pulled, beads pull rubber bands separately over the edge of the front part of the cylinder and ligate the tissue suctioned in the cylinder. Pulling of the string is performed by a mechanical device attached to the hand of the scope. The mechanical device consists of a knob to which the string is attached. When the knob is rotated by an operator, the string wraps around its central part thus pulling the string and by shortening it, releases the band from the attached cylinder to the tip of the endoscope. As a result, the rubber bands and beads of these variceal ligators cause the outer surface of the cylinder that is to be inserted into the body to be course, thus making it more difficult to insert the ligator into smaller orifices. Furthermore, these devices are not designed for reloading bands. 
         [0007]    Other prior art devices include a single band device. These devices allow release of a single band only off the surface of the inner cylinder being pulled inside the outer cylinder by a simple pull of the string. These devices do not provide releasing of multiple bands. 
         [0008]    Another prior art ligator is disclosed in U.S. Pat. No. 7,641,652 to Koe et al. channel (the “Koe reference”). The Koe reference discloses a large ligating device mounted substantially spaced from the end of an endoscope. The Koe device includes a mounting arm and other structure surrounding the penetrating end of the endoscope, and the ligating device is transverse to the endoscope viewing component. The Koe device blocks the operator&#39;s view of the material to be ligated, so it renders the ligating process difficult and requires significant operator training to use the device with relative accuracy. The Koe device also is bulky and includes substantial edges, wire (including rotating wire), and other components that make introduction into the esophagus difficult, if not impossible. 
       SUMMARY OF THE DISCLOSURE 
       [0009]    The applicant has recognized shortcomings of the prior art devices. As a result, the applicant has developed a generally tubular ligator mountable to an endoscope with the axis of the ligator generally aligned with an axis of the working end of the endoscope. In some embodiments, the axis of the ligator in parallel to, and in some embodiments coaxial with, the central axis of the working end of the endoscope. The ligator pushes one or more ligation bands off the end of the ligator by rotating around the ligator axis, and thereby moving, a first ligator structure with respect to a second ligator structure. 
         [0010]    In certain embodiments, the rotation is caused by pulling a line or other component. In some embodiments, this component extends from the ligator through a working channel of the endoscope. In some instances, a portion the line wraps around or along the surface or periphery of the first or second ligator structure and is pulled at a substantial angle to, and in some embodiments transversely to, the axis of the ligator. 
         [0011]    In certain embodiments, the first ligator structure is a first cylinder, and the second ligator structure is a second cylinder having a differing diameter than the first cylinder. In some embodiments, cylinders have mating threaded sections and associated structure, such as for example, the pulling line causing the relative rotation of the first and second cylinder. 
         [0012]    In some embodiments, the relative rotation of the cylinders causes one cylinder portion to urge a ligator band off of a second cylinder portion. In some instances, the ligator includes a mount for mounting the ligator to the working end of an endoscope. 
         [0013]    Methods of operation of the ligator are also disclosed herein. In one embodiment, an operator causes the relative rotation of the cylinders to urge a ligation band onto adjacent structure, such as bulging or other tissue for example. In some embodiments, this relative rotation is caused by pulling of a line or other link between the ligator and operator. In some embodiments, the relative rotation forces a ligation band to move off of one of the ligator cylinders. 
         [0014]    In some embodiments, the operator can see through the ligator during use of the ligator on the working end of the endoscope. 
         [0015]    Some embodiments include a novel line or cord pulling assembly. This assembly can include an indexed line puller to controllably pull the line in predetermined increments. Certain embodiments can include opposed arcuate mounting arms; and if desired the opposed arcuate mounting arms can provide a mounting channel, allowing structure, such as endoscope, to pass through the channel. Some cord pulling assemblies can include a securing member, such as a transverse removable pin for example, to help secure the cord pulling assembly in position on, for example, an endoscope. In some instances, the arcuate mounting arms and securing member cooperatively secure the endoscope in position. The latter arrangement can make the cord pulling assembly easy to mount on a device (such as an endoscope for example), secure in position for use, and later remove from the device on which the assembly was mounted. 
         [0016]    There are many other novel features, problem solutions, advantages, and aspects of the present disclosure. They will become apparent as the specification proceeds. 
         [0017]    There are other aspects and advantages of the present apparatus and methods disclosed by the present specification. They will become apparent as the specification proceeds. In this regard, it is to be understood that the Background and this Brief Summary are not intended to be limiting, and thus the scope of the invention is to be determined by the claims as issued and not whether given subject matter addresses an issue noted in the Background or includes subject matter recited in this Brief Summary. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]    The applicants&#39; preferred and other embodiments are further disclosed in association with the accompanying drawings, in which: 
           [0019]      FIG. 1  is a perspective view of one embodiment of the present ligator apparatus having a ligator mounted on a penetrating end of an endoscope and a cord pulling assembly mounted over; 
           [0020]      FIG. 2  is a top plan view of the ligator apparatus of  FIG. 2 ; 
           [0021]      FIG. 3  is a cross-sectional view taken along section line  3 - 3  of  FIG. 2 ; 
           [0022]      FIG. 4  is an expanded partial cross-sectional view of the ligating end of the ligator apparatus shown in the cross-sectional view of  FIG. 3 ; 
           [0023]      FIG. 5  is an expanded partial perspective view of the cord pulling apparatus mounted adjacent the endoscope control end as shown in  FIG. 1 ; 
           [0024]      FIG. 6  is a perspective view of the cord pulling frame of the cord pulling assembly of  FIG. 5 ; 
           [0025]      FIG. 7  is a perspective view of indexed pulling knob of the cord pulling apparatus of  FIG. 5 ; 
           [0026]      FIG. 8  is a perspective view of the anchor pin of the cord pulling apparatus of  FIG. 5 ; 
           [0027]      FIG. 9  is a perspective view of the ligator of  FIG. 1 ; 
           [0028]      FIG. 10  is a perspective view of the ligator of  FIG. 9  but with the outer ring having ejected four bands from the inner ring; 
           [0029]      FIG. 11  is a first side elevational view of the ligator of  FIG. 9  showing the external cord slot in the outer barrel; 
           [0030]      FIG. 12  is a cross-sectional elevational view of the ligator of  FIG. 9  taken along section  12 - 12  of  FIG. 9 ; 
           [0031]      FIG. 13  is a perspective view of the outer barrel of the ligator of  FIG. 9  with the inner barrel rotated through multiple threading rotations with respect to the outer barrel and laterally moved completely within the interior of the outer barrel; 
           [0032]      FIG. 14  is a side elevational view of the outer and inner barrels of  FIG. 13 ; 
           [0033]      FIG. 15  is a cross-sectional view of the outer barrel taken along section line  15 - 15  in  FIG. 13  (i.e., with the inner barrel not included in this view); 
           [0034]      FIG. 16  is a cross-sectional view of the outer barrel taken along section line  16 - 16  in  FIG. 14  (i.e., with the inner barrel not included in this view); 
           [0035]      FIG. 17  is a is perspective view of the inner barrel of the ligator of  FIG. 9 ; 
           [0036]      FIG. 18  is a perspective view of the outer sealing ring on the outer barrel of the ligator of  FIG. 9 ; 
           [0037]      FIG. 19  is a perspective view of the band driving ring abutting the driving end of the outer barrel of the ligator of  FIG. 9 ; 
           [0038]      FIG. 20  is a perspective view of the intermediate rubber mounting adapter of  FIG. 21 ; 
           [0039]      FIG. 21  is a cross-sectional view of the intermediate rubber mounting adapter taken along section line  23 - 23  of  FIG. 22 ; 
           [0040]      FIG. 22  is a side plan view of an alternative ligator mounted directly to the penetrating end of an endoscope; 
           [0041]      FIG. 23  is side plan view of an embodiment of the ligator of  FIG. 20  mounted via an intermediate rubber mounting adapter to the penetrating end of an endoscope; 
           [0042]      FIG. 24  is a perspective view of a pulling cord installed in the outer barrel of the ligator of  FIG. 1 ; 
           [0043]      FIG. 25  is a somewhat perspective view of the cord-bearing ligator outer barrel of  FIG. 24  mounted onto the cord-bearing inner barrel of  FIG. 25 ; 
           [0044]      FIG. 26  is a somewhat perspective view of the outer and inner barrels of  FIG. 26  with ligating bands (ligatures) aligned for mounting on the ligator inner barrel; 
           [0045]      FIG. 27  is a somewhat perspective view of the outer and inner barrels of  FIG. 27  but with the ligating bands mounted on the ligating end of the ligator inner barrel; and 
           [0046]      FIG. 28  is top somewhat perspective view of a portion of the band pulling assembly with the pulling cord mounted on, and partially wound around, the rotatable pulling knob in the band pulling assembly. 
       
    
    
       [0047]    It is to be understood that spacially-orienting terms, such as top, bottom, front, back, upwardly, or downwardly are used to explain relative orientation of structures as shown in the Figures and as the structures might be used. They are not to be construed, however, to require such an orientation in space. 
       DETAILED DESCRIPTION 
       [0048]      FIGS. 1-29  depict ligators and other structures that can be utilized to ligate flesh such as one or more esophageal varices. These ligators, others including various of their features, and varying associated ligator components and methods can be variously used to ligate other material, human or otherwise. 
         [0049]    With reference now to  FIG. 1 , one embodiment of a ligator assembly, generally  40 , includes a generally tubular endoscope  41  with a removable ligator  42  mounted on a penetrating end  44  of the endoscope  41  and a cord pulling assembly  46  removably mounted on an access channel  48  adjacent the control end  50  of the endoscope  41 . An operator, such as a medical practitioner for example, can cause the cord pulling assembly  46  to pull a cord  47  through interior of the endoscope  41  and cause the ligating end  52  of the ligator  42  to eject a ligating band  54 . The particular endoscope  41  shown in  FIG. 1  is an Olympus Video Gastroscope. 
         [0050]    Turning now to  FIG. 2 , the ligator  42  is generally tubular and is mounted within a generally tubular elastic mounting adapter  56 , which in turn is mounted to the penetrating end  44  of the endoscope  41 . On the opposing control end  50  of the endoscope  41 , the cord pulling assembly  46  is mounted to surround the access channel  48  in order to pull the cord  47  from the interior of the endoscope  41  through the access channel  48 . 
         [0051]    Referring now to  FIG. 3 , the pulling cord  47  extends from pulling rod  58  in the cord pulling assembly  46  through the working channel (not shown) that runs from the outer open end  60  of the access channel  48  through to the open penetrating end  44  of the endoscope  41 . For human applications, the pulling cord  47  is FDA-approved material on the ligating end. The pulling cord can be made of one material throughout its length, or it can include an intermediate differing type of cord or connector such as a wire, plastic line, monofilament, braided line, etc. 
         [0052]    The interior of the endoscope  41  also includes a user viewing or image transmission channel or member (not shown) that extends from the endoscope viewing lens end  62  to the opposed open penetrating end  44 , allowing the operator to see through the endoscope&#39;s penetrating end  44  when inserted into a patient&#39;s esophagus for example. In turn, the ligator  42  has a central passage  64  that allows light to pass through the center of the endoscope  41 , which in turn allows the operator to look through the viewing lens end and see through the penetrating end  44  of the endoscope  41  and the ligator  42  as well. 
         [0053]    In this embodiment, the front end  66  of the cord pulling assembly  46  is somewhat conical. This conical front end  66  is adapted to mount about the penetrating end  44  of the endoscope  41  and slide into place abutting a matingly conically configured external periphery  68  of the endoscope  41 . Differently configured cord pulling assemblies (not shown) can be shaped differently for differing endoscope configurations. 
         [0054]    With reference now to  FIG. 4 , the pulling cord  47  extends from the penetrating end  41  of the endoscope  41  to enter cord channeling structure, generally  70 , in the ligator  42 . When the pulling cord  47  is pulled by the cord pulling assembly ( 46  in  FIG. 3 ), the ligator  42  is driven to eject the end ligating band  54  among the four ligating bands  54 ,  72 ,  74 ,  76  on the end of the ligator  42 . 
         [0055]    With reference to  FIG. 5 , the cord pulling assembly  46  includes: (i) an indexed knob  78  at one end of the pulling rod  58  transversely penetrating mating laterally opposed, coaxial knob rod passages, e.g.,  79 , in the upwardly extending upper end  82  of the central mounting body  80  in the assembly  46 ; and (ii) a mounting pin  84  transversely penetrating mating laterally opposed, coaxial mounting pin passages, e.g.,  85 , a lower end  86  of the central mounting body  80  adjacent the outer periphery  88  of the control end  50  of the endoscope  41 . The components of the cord pulling assembly can be made from a variety of materials, such as for example plastic, various metals, rubber, etc. 
         [0056]    Referring to  FIGS. 5 and 6 , the central mounting body  80  of the cord pulling assembly  46  (see  FIG. 5 ) has: (i) an upwardly extending and outwardly facing thumb-grip depression or channel  90  on one laterally extending, generally planar side  92  intermediate the upwardly extending end  82  and the lower end  86  of the mounting body  80 ; and (ii) an upwardly extending and outwardly facing finger-grip depression or channel  94  on the opposed laterally extending, generally planar side  96  of the mounting body  80 , also intermediate the upwardly extending end  82  and the lower end  86  on the mounting body  80 . With reference to both  FIGS. 5 and 6 , the thumb-grip depression  90  extends at an acute angle to one laterally extending bottom edge  98  of the mounting body  80 , and the finger-grip depression  94  is nearly transverse to the opposed bottom edge  99 . The one bottom edge  98  and opposed bottom edge  99  are coplanar and at a slightly acute angle to, and spaced upwardly from, the axis of the generally conical front end  66  of the mounting body  80 . A top side planar frame member  102  extends between the opposed upwardly extending top lateral edges  104 ,  106  intermediate and interconnecting the opposed thumb grip depression  90  and finger grip depression  94 . 
         [0057]    Referring back to  FIG. 5 , the central mounting body  80  includes an endoscope access channel passage  100  intermediate the pulling rod  58  and the mounting pin  84 . This passage  100  allows an endoscope access channel  48  to open relatively directly below and adjacent the pulling rod  58  and above and adjacent the mounting pin  84 . The axis of the pulling rod  58  is thus laterally transverse to the axis of the access channel  48  and parallel to the axis of the mounting pin  84 . Similarly, the axis of the mounting pin  84  and axis of the pulling rod  58  is transverse to the opposed laterally extending sides  92 ,  96  of the mounting body  80 . As shown in  FIG. 3 , this pin  84  can abut external periphery of the endoscope  41  and secures the cord pulling assembly in position on the endoscope  41  between that abutment and the upwardly extending access channel  48 . 
         [0058]    Referring now to  FIG. 7 , the indexed knob  78  has finger grip depressions or channels, e.g.,  105 ,  107  transverse to the axis of the indexed knob  78  penetrating the otherwise generally circumferential outer periphery  109  of the knob  78 . The indexed knob  78  also includes the central pulling rod  58  extending transversely from the axial center (not shown) of a radially outwardly extending knob handle  108 . 
         [0059]    The handle abutting end (not shown) of rod  58  has a hub section  110  also extending radially outwardly from the central mounting rod  58 . The outer edge  112  of the hub section  100  abuts and extends from the generally planar interior side  114  of the knob handle  108 . A radially outwardly extending interior hub side  116  extends from the outer periphery of the central rod  58  to the outer radial periphery cylindrical outer surface  118  of the hub section  110 . 
         [0060]    The interior hub side  116  has four rounded index projections, e.g.,  120 ,  122 , extending inwardly in the direction of the rod arm  125  extending from the hub section  110 . Each pair of the index projections, e.g.,  120 ,  122 , are spaced from each other by an equal distance. The index projections, e.g.,  120 ,  122 , penetrate, as shown in  FIG. 6 , mating index depressions or dimples, e.g.,  124 ,  126 , in the mating side  92  of the mounting body  80  surrounding the rod passage  79 . 
         [0061]    The central rod  58  has a lock washer mounting end  128  opposite the handle abutting end (not shown). A pulling cord slot  130  penetrates the outer periphery of the rod  58  (i) transverse to the axis of the rod  58  and (ii) intermediate the lock washer mounting end  128  and the interior hub side  116 . The pulling cord slot  130  has a widened knot mounting channel end  132 , providing a cavity for securely seating a pulling cord knot or other similar structure in the pulling cord slot  130 . 
         [0062]    Referring to  FIGS. 5 and 7 , a lock washer  134  is mounted on the lock washer mounting end  128  of the central rod  58  to bias the interior hub side  116  against, as shown in  FIG. 6 , the hub side mating section  136  surrounding the rod passage  79 . With reference to  FIGS. 5, 6 , and  7 , the central rod  50  is thereby rotatably mounted within the rod passages, e.g.,  79 , but is urged to stop (index) as the four mating projections, e.g.,  120 ,  122 , penetrate four opposed mating dimples, e.g.,  124 ,  126  due to the biasing provided by the lock washer  134 . 
         [0063]    With reference now to  FIG. 8 , the mounting pin  84  has a widened mounting knob end  138 , a narrower mounting pin hub  140  extending from the mounting knob end  138 , a still narrower inner mounting rod section  142  extending from the mounting pin hub  140 , and a still narrower end mounting pin rod end  144  extending laterally from the mounting pin section. The knob end  138 , pin hub  140 , inner mounting rod section  142 , and end mounting pin rod  144  are all coaxial with each other. 
         [0064]    Referring now to  FIG. 9 , the ligator  42  has a fixed band-ejector outer barrel  146  coaxially surrounding a rotatable band-mounting inner barrel  148 . The fixed band-ejector outer barrel  146  is held in a fixed position with respect to the endoscope  41  penetrating end  44  by the mounting end  154  of the outer barrel  146  and by the mounting adapter  56  and its friction grip on the matingly abutting outer periphery (not shown in  FIG. 9 ) of the endoscope penetrating end  44  and ligator  42 . 
         [0065]    This embodiment of the outer barrel  42  has a band driving end  152  opposite the outer barrel mounting end  154  within the mounting adapter  56 . A C-shaped sealing ring  150  (see also  FIG. 18 ) surrounds a central cord slot section  153  in the outer barrel  146  intermediate the band driving end  152  and the mounting end  154  of the ligator  42 . 
         [0066]    The inner barrel  148  has a band mounting end  156  extending outwardly from the band driving end  152  of the outer barrel  146 . A resilient band-driving circular washer  158  (see also  FIG. 19 ) is (i) mounted about, and abuts with a friction grip, the outer periphery of the band mounting end  152  of the inner barrel  148  and (ii) abuts the band driving end  152  of the outer barrel  146 . 
         [0067]    Referring now to  FIG. 10 , when the inner barrel  148  is rotated by pulling the pulling cord (not shown), the inner barrel  148  moves along the fixed outer barrel  146  and circular washer  158  to drive the ligatures  56 ,  72 ,  74 ,  76  off of the band mounting end  152  of the ligator  42 . 
         [0068]    With reference now to  FIG. 11 , the ligator inner barrel  148  includes a threaded external peripheral section  160  matingly threadable with a threaded internal peripheral section  162  within the outer barrel  146 . As a result, rotation of the inner barrel  148  with respect to the outer barrel  146  can drive the inner barrel  148  further into the interior of the outer barrel  146 , in turn forcing the band-driving washer  158  to force a ligator band, e.g.,  54 , of the ligating or band-mounting end  156  of the inner barrel  148 . 
         [0069]    With collective reference now to  FIGS. 11, 14, and 16 , the outer barrel  146  has a somewhat L-shaped, curved cord channel or depression  161  in the central cord-slot section  153 . The cord channel  161  has: (i) a laterally extending section  163  coaxial with both the axis of the ligator  42  and the axis of the penetrating end  44  of the endoscope  41 ; (ii) a transverse section  164  extending transverse to the laterally extending section  162  and being coplanar with the barrel radius extending from the axis of the outer barrel  146  to the transverse section  164 ; (iii) a curved cord channel section  166  intermediate and interconnecting the laterally extending section  163  and radially extending section  164 ; (iv) a first cord passage  168  (see also  FIG. 12 ) at the outer end of the transverse section  164  perpendicularly extending into the interior of the outer barrel from the transverse section  164 ; and (v) a second cord passage  170  at the outer end of the laterally extending section  163  perpendicularly extending into the interior of the outer barrel  146  from the laterally extending section  163 . 
         [0070]    As a result, the pulling cord (not shown in  FIG. 11 ) can pass from the interior of the outer barrel  146  through the second cord passage  170 , through the cord channel  161  and back into the interior of the outer barrel  146  through the first cord passage  168 . With reference to  FIGS. 12 and 15 , the first cord passage  168  extends radially inwardly toward the outer periphery of the inner end  174  of the inner barrel  148  and spaced axially laterally from the inner barrel threaded section  162  toward the endoscope penetrating end  44 . With reference to  FIG. 14 , when the inner barrel  148  is rotated and laterally moved within the interior of the outer barrel  146 , the first cord passage  168  in the outer barrel  146  is aligned coaxially with an inner barrel cord passage  187  in the inner barrel  148 . 
         [0071]    With continuing reference to  FIG. 12  and additional reference to  FIG. 17 , the inner end  174  of the inner barrel  148  is tubular. The outer circumference of the inner end  174  is substantially less than the inner circumference of adjacent, surrounding section  176  of the outer barrel  146 , providing a cord wrapping area  177  between the inner end  174  and surrounding section  176 . A pulling cord (not shown) can thus pass through the first cord passage  168  and wrap around the outer circumference of the inner end  174  within the confines of surrounding section  176  of the outer barrel  146 . 
         [0072]    With the four ligating bands  54 ,  72 ,  74 ,  76  mounted on the inner barrel  148 , the inner end  174  of the inner barrel  148  is spaced laterally from thus penetrating end  44  of the endoscope as well as an interior barrier ridge  178  extending radially inwardly from the interior periphery of the outer barrel  146 . This spacing forms penetrable space  180  within the outer barrel  146  into which the inner barrel  148  inner end  174  may move when the inner barrel  148  is rotated in one direction with respect to the outer barrel  146 . 
         [0073]    Turning now to  FIG. 13 , the central cord slot section  153  in the outer barrel  146  has a somewhat narrower outer diameter than, and is intermediate and abuts, the band driving section  180  and mid-section  182  in the outer barrel  146 . The band driving section  180  and mid-section  182  have the same outer diameter. With reference now to  FIG. 11 , the outer diameter of widened outer barrel mounting portion  183  of the mounting adapter  56  is (i) wider than the outer diameter of the underlying adapter mounting section  186  of the outer barrel  146 , but (ii) only slightly larger than the outer diameter of the mid-section  182 , which the mounting adapter  56  abuts. 
         [0074]    With reference to  FIGS. 12 and 17 , the inner barrel  148  has a radially extending cord passage  187  extending radially inwardly from the outer periphery to the inner periphery in the interior end  174  of the inner barrel  148 . A pulling cord can thus penetrate this cord passage  187  and be knotted in the interior of the inner barrel  148 . 
         [0075]    With reference back to  FIG. 12 , with the sealing ring  150  mounted about and abutting the central cord slot section  153 , the external periphery of the collective band driving section  180 , sealing ring  150 , mid-section  182 , and mounting adapter  56  cooperatively provide a relatively smooth outer ligator surface  184  with a relatively narrow cross-section that is (i) readily and easily slidable through the type of human oropharynx into the esophagus with which the given endoscope is designed for use, yet (ii) sufficiently wide for the endoscope operator to see through the interior of the ligator  42 . 
         [0076]    Referring now to  FIG. 18 , the sealing ring  150  has a somewhat tubular shape. Referring to  FIG. 19 , the band-driving washer  158  has a thickened band-driving end  185  and a relatively thinner opposed end  189   
         [0077]    With reference back to  FIG. 11 , the outer barrel  146 , inner barrel  148  and sealing ring  150  can be made of stainless steel. The band-driving washer  158  can be made out of plastic and the ligating bands, e.g.,  54 , are commercially available. The mounting adapter  56  can be made of rubber or silicone. 
         [0078]    With reference now to  FIGS. 20 and 21 , the mounting adapter  56  has a narrowed endoscope mounting section  191  extending from the widened outer barrel mounting portion  183 . A sloped neck  193  joins the outer periphery of the widened outer barrel mounting portion  183  and the outer periphery of the narrowed endoscope mounting section  191 . 
         [0079]    The mounting adapter  56  is optional. It can be dispensed with particularly when there may be a poor seal between the ligator  42  and the penetrating end  44  of the endoscope  41 . When the mounting adapter  56  is not used, the overall diametral width of the ligator  41  is reduced, which can be beneficial to reduce the level of contact of the ligator  41  with surrounding flesh for example. 
         [0080]    Referring now to  FIG. 22 , an alternative embodiment of a ligator  186  includes an inner band-bearing barrel  188  mounted within an outer band-driving barrel  190  and a cord slot seal tube  192  rotatably mounted about (and friction gripping) the mid-section  196  of the outer barrel  190 . A narrowed outer barrel mounting section  198  extends from the mid-section  196  through a central ring passage  197  in the seal tube  192  and provides a friction grip mount  200  about the penetrating end  202  of an endoscope  204 . 
         [0081]    The seal tube  192  includes a laterally extending cord slot access channel  206 . The cord slot access channel  206  provides operator access to an outer barrel access channel (not shown) and mating passages (not shown) into the interior of the outer barrel  190  in the fashion described above when the seal tube  192  is rotated to expose a cord access channel (not shown) within the cord slot access channel  206  in the seal tube  196  (such cord access channel being structured as described above for the access channel  160 ). Stretched ligating bands  208 ,  210  are friction-fit mounted about the band-bearing section  212  of the inner barrel  188  adjacent a band-driving rubber ring or band driving washer  214  friction-grip mounted on the band-bearing section  212  to abut the opposed band-driving end  214  of the outer barrel  190 . 
         [0082]    With reference now to  FIG. 23 , an alternative method of mounting the ligator  186  utilizes a somewhat tubular rubber mounting adapter  216  friction fit on one end  218  about the external periphery of the mounting end  220  of the ligator  186  and friction fit on the opposed, narrower end  222  about the external periphery of the penetrating end  202  of the endoscope  204 . 
         [0083]    A method of use of the ligation systems can include the following steps (altered as necessary for any varying structures): 1. With reference to  FIG. 1 , mount the pulling assembly  46  to the endoscope  41  as explained above. 2. With reference to  FIGS. 12, 13, and 24 , if necessary, rotate the sealing ring  150  to expose the outer barrel cord channel  161 . 3. Thread the inner barrel threads  160  on the mating outer barrel threads  162  all the way into the outer barrel  146  to align the first outer cord passage  168  with the inner barrel cord passage  187 , insert a pulling cord  47  through the these cord passages  168 ,  187 , and knot the end  230  of the pulling cord within the inner barrel  148 . 4. Insert the un-knotted portion  232  of the pulling cord (extending from the cord passage  187  of the inner barrel  148 ) through the second cord passage  172  in the outer barrel  146 . 5. Pull the un-knotted portion  232  of the pulling cord out of the interior of the outer barrel  146  through its mounting end  154  so that the pulling cord lies within the outer barrel cord channel  161  and the knot  230  is snug inside the inner barrel  48 . 6. Rotate the sealing ring  150  to cover the outer barrel cord channel  161  and portion of the pulling cord within the channel  161 . 7. With reference now to  FIGS. 12, 13, and 25 , rotate the inner barrel  148  within the mating threads  162  in the outer barrel  146  to push the inner barrel band mounting end  156  laterally out of the interior of the outer barrel  146 , which in turn causes the pulling cord, e.g.,  233 , to be pulled into the confined area  177  and coil around the inner end  174  of the inner barrel  148  without having the pulling cord wrap  233  onto itself. 8. With reference now to  FIG. 25 , tie a knot at the free end (not shown) of the pulling cord  234  (which is approximately 4 feet in length). 9. With reference to  FIGS. 26 and 27  and when applicable (e.g., when the ligator is not pre-loaded with one or more ligator bands), mount the band-driving washer  158  and one or more of the desired number of ligating bands, e.g.,  236 ,  238 , on the ligating end of the ligator  42 . 10. With general reference to  FIG. 3 , pass the free end  232  of the pulling cord  47  (with the help of commercially available biopsy forceps or hooked plastic tubing) through the endoscope&#39;s working channel to exit the endoscope access channel  48 . 11. With general reference to  FIG. 1  and  FIG. 13 , place the penetrating end of the endoscope  44  into the mounting end of the outer barrel  146 . If a proper seal is not achieved, disconnect the penetrating end of the endoscope  44  from the mounting end of the outer barrel  146  and mount the mounting adapter  56  to the penetrating end  44  of the endoscope  41 . 12. With reference to  FIG. 28 , thread the un-knotted end  232  of the pulling cord through the pulling cord slot  130 ; tie another knot  234  in the un-knotted end  232 , and pull the pulling cord through the pulling cord slot  130  so that this latter knot  234  is held in place within the widened cord slot end  132 . 13. With general reference back to  FIG. 1  and  FIG. 28 , rotate the knob handle  108  to wind free pulling cord onto the pulling rod  58 . 14. With general reference to  FIG. 1 , insert the mounted ligator  42  into the patient&#39;s esophagus. 15. Look through the endoscope viewing lens in the viewing lens end  62  of the endoscope, and locate an esophageal varix. 16. While continuing to look through the endoscope and ligator: press the ligator ligating end  52  to surround the located varix; apply suction via the suction channel of the endoscope to pull the tissue inside the inner barrel  148 ; rotate the knob handle  108  to wind pulling cord onto the pulling rod  58 —continue doing so one index click at a time until the bulge of the varix within the ligating end  52  of the ligator  42  reflects that a ligating band has been ejected from the ligating end  52  to surround the base of the varix as desired. 17. When applicable, repeat steps 15-16 until all desired varices are ligated or all ligating bands have been ejected from the ligator. 18. Withdraw the ligating assembly from the patient&#39;s esophagus. Optional additional steps to include when and as applicable: 19. Dispose of the pulling cord except for reusable portions. 20. Dispose of the non-reusable portions of the ligator  42 . 21. Treat the reusable portions of the ligator and pulling cord with suitable disinfecting treatment and re-use or store them for later use as applicable. 
         [0084]    Referring now to  FIG. 1 , the resulting ligator assembly is extremely strong, economical, durable, and relatively lightweight. The method of use is accurate, easy, and quick, allowing the practitioner or other operator to see through the endoscope and ligator as desired and without blocking the practitioner&#39;s view during the procedure. The assembly preparation steps 1-14 and 18-21 can be performed by personnel other than a medical practitioner to reduce cost and use of time of the medical practitioner. 
         [0085]    The ligator may also be made and supplied to users with or without one or more ligating bands preloaded on the ligator. In the latter event, users can load conventional, off-the-shelf rubber bands on the ligator with a conventional band loader. 
         [0086]    The ligator and cord pulling assembly may be made of disposable materials. Alternatively, the ligator and cord pulling assembly, or one or more of their components, may be made of materials that can be disinfected and re-used. 
         [0087]    This description is not to be construed as limiting. Further, various components of embodiments disclosed herein may be mixed and matched with each other to yield further arrangements of the features disclosed herein.