Patent Publication Number: US-11648027-B2

Title: Endoscopic snare device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 15/401,545 filed Jan. 9, 2017, which is a continuation of U.S. application Ser. No. 14/565,024, filed Dec. 9, 2014, now U.S. Pat. No. 9,572,591, which is a continuation-in-part of U.S. application Ser. No. 14/016,906, titled “ENDOSCOPIC SNARE DEVICE,” and filed on Sep. 3, 2013, now U.S. Pat. No. 9,872,700. The entire disclosures of the above referenced applications are fully incorporated herein by reference. 
    
    
     BACKGROUND 
     Endoscopes are well-known in the medical arts and are commonly used for numerous medical procedures. One such procedure is removing targeted tissue from the gastrointestinal mucosal wall of a human subject. Various types of tissue, such as for example, polyps, lesions, tumors or adenomas, may be removed for various medical purposes, such as for example, treatment or diagnostic testing. 
     One conventional polypectomy technique for removing targeted tissue is cauterization. For example, cauterizing devices may be used to remove an unwanted polyp. A cauterizing device uses heat to separate the targeted tissue from the gastrointestinal wall of a patient. The removed tissue may be discarded or captured for testing. 
     Mechanical devices, such as for example, snares, are also known in the art. For example, a snare may be used to separate a polyp from the gastrointestinal wall of a patient. Specifically, an operator may deploy or open a snare loop, and position the snare around a polyp. By retrieval or closing of the snare loop, the operator can cut into the tissue and separate the tissue from the gastrointestinal wall. Subsequently, the operator may use a suction source to capture and retain the tissue after separation from the wall. 
     SUMMARY 
     The present application describes a tissue removal tool for use with an endoscope, such as for example, a snare suitable for use in removing a gastrointestinal polyp. 
     In an exemplary embodiment, the tool includes a loop. The loop is movable between an open position and a closed position. The loop is advantageously shaped in the open position for tissue removal and includes-collapse resistant bends. 
     Further features and advantages of the invention will become apparent from the following detailed description made with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Features and advantages of the general inventive concepts will become apparent from the following detailed description made with reference to the accompanying drawings. 
         FIG.  1    is a perspective view of a retrieval device, showing a snare in an open position; 
         FIG.  2    is an enlarged sectional view of a portion of the retrieval device of  FIG.  1   , showing the snare in a closed position within a conduit; 
         FIG.  3    is a top view of the snare of  FIG.  1   , showing the snare in an open or deployed position; 
         FIG.  3   a    is an enlarged perspective view of the designated circular area of  FIG.  3   ; 
         FIG.  3   b    is sectional view of the snare of  FIG.  3   , shown along the line  3   b - 3   b  of  FIG.  3   ; 
         FIG.  3   c    is sectional view of the snare of  FIG.  3   , shown along the line  3   c - 3   c  of  FIG.  3   ; 
         FIG.  3   d    is sectional view of the snare of  FIG.  3   , shown along the line  3   d - 3   d  of  FIG.  3   ; 
         FIG.  3   e    is sectional view of the snare of  FIG.  3   , shown along the line  3   e - 3   e  of  FIG.  3   ; 
         FIG.  3   f    is an enlarged perspective view of the designated circular area of  FIG.  3   ; 
         FIG.  3   g    is an enlarged view of another snare having another distal end; 
         FIG.  4    is a top view of another snare, showing the snare in a deployed position; 
         FIG.  4   a    is an enlarged perspective view of the designated circular area of  FIG.  4   ; 
         FIG.  4   b    is sectional view of the snare of  FIG.  4   , shown along the line  4   b - 4   b  of  FIG.  4   ; 
         FIG.  4   c    is sectional view of the snare of  FIG.  4   , shown along the line  4   c - 4   c  of  FIG.  4   ; 
         FIG.  4   d    is sectional view of the snare of  FIG.  4   , shown along the line  4   d - 4   d  of  FIG.  4   ; 
         FIG.  4   e    is sectional view of the snare of  FIG.  4   , shown along the line  4   e - 4   e  of  FIG.  4   ; 
         FIG.  5    is a top view of another snare, showing the snare in a deployed position; 
         FIG.  5   a    is an enlarged perspective view of the designated circular area of  FIG.  5   ; 
         FIG.  5   b    is sectional view of the snare of  FIG.  5   , shown along the line  5   b - 5   b  of  FIG.  5   ; 
         FIG.  5   c    is sectional view of the snare of  FIG.  5   , shown along the line  5   c - 5   c  of  FIG.  5   ; 
         FIG.  5   d    is sectional view of the snare of  FIG.  5   , shown along the line  5   d - 5   d  of  FIG.  5   ; 
         FIG.  5   e    is sectional view of the snare of  FIG.  5   , shown along the line  5   e - 5   e  of  FIG.  5   ; 
         FIG.  6    is a top view of another snare, showing the snare in a deployed position; 
         FIG.  6   a    is an enlarged perspective view of the designated circular area of  FIG.  6   ; 
         FIG.  6   b    is sectional view of the snare of  FIG.  6   , shown along the line  6   b - 6   b  of  FIG.  6   ; 
         FIG.  6   c    is sectional view of the snare of  FIG.  6   , shown along the line  6   c - 6   c  of  FIG.  6   ; 
         FIG.  6   d    is sectional view of the snare of  FIG.  6   , shown along the line  6   d - 6   d  of  FIG.  6   ; 
         FIG.  6   e    is sectional view of the snare of  FIG.  6   , shown along the line  6   e - 6   e  of  FIG.  6   ; 
         FIG.  7    is a top view of another snare, showing the snare in a deployed position; 
         FIG.  7   a    is an enlarged perspective view of the designated circular area of  FIG.  7   ; 
         FIG.  7   b    is sectional view of the snare of  FIG.  7   , shown along the line  7   b - 7   b  of  FIG.  7   ; 
         FIG.  7   c    is sectional view of the snare of  FIG.  7   , shown along the line  7   c - 7   c  of  FIG.  7   ; 
         FIG.  7   d    is sectional view of the snare of  FIG.  7   , shown along the line  7   d - 7   d  of  FIG.  7   ; 
         FIG.  7   e    is sectional view of the snare of  FIG.  7   , shown along the line  7   e - 7   e  of  FIG.  7   ; 
         FIG.  8    is a top view of another snare, showing the snare in a deployed position; 
         FIG.  8   a    is an enlarged perspective view of the designated circular area of  FIG.  8   ; 
         FIG.  8   b    is sectional view of the snare of  FIG.  8   , shown along the line  8   b - 8   b  of  FIG.  8   ; 
         FIG.  8   c    is sectional view of the snare of  FIG.  8   , shown along the line  8   c - 8   c  of  FIG.  8   ; 
         FIG.  8   d    is sectional view of the snare of  FIG.  8   , shown along the line  8   d - 8   d  of  FIG.  8   ; 
         FIG.  8   e    is sectional view of the snare of  FIG.  8   , shown along the line  8   e - 8   e  of  FIG.  8   ; 
         FIG.  9   a    is a top view of another snare having an irregular shape; 
         FIG.  9   b    is a top view of another snare having an irregular shape; 
         FIG.  9   c    is a top view of another snare having a hexagon shape; 
         FIG.  9   d    is a top view of another snare having an oval-shape; 
         FIG.  9   e    is a top view of another snare having an oval-shape; 
         FIG.  9   f    is a top view of another snare having an irregular shape; 
         FIG.  10   a    is perspective view of a portion of a snare having a diamond-shape, shown in a similar orientation as the snare in  FIG.  3     a;    
         FIG.  10   b    is a sectional view of the snare of  FIG.  10   a   , shown in an orientation similar to the sectional view of  FIG.  3     b;    
         FIG.  10   c    is a sectional view of the snare of  FIG.  10   a   , shown in an orientation similar to the sectional view of  FIG.  3     c;    
         FIG.  10   d    is a sectional view of the snare of  FIG.  10   a   , shown in an orientation similar to the sectional view of  FIG.  3     d;    
         FIG.  11   a    is perspective view of a portion of a snare having an oval-shape, shown in a similar orientation as the snare in  FIG.  3     a;    
         FIG.  11   b    is a sectional view of the snare of  FIG.  11   a   , shown in an orientation similar to the sectional view of  FIG.  3     b;    
         FIG.  11   c    is a sectional view of the snare of  FIG.  11   a   , shown in an orientation similar to the sectional view of  FIG.  3     c;    
         FIG.  11   d    is a sectional view of the snare of  FIG.  11   a   , shown in an orientation similar to the sectional view of  FIG.  3     d;    
         FIG.  12   a    is perspective view of a portion of a snare having a square-shape, shown in a similar orientation as the snare in  FIG.  3     a;    
         FIG.  12   b    is a sectional view of the snare of  FIG.  12   a   , shown in an orientation similar to the sectional view of  FIG.  3     b;    
         FIG.  12   c    is a sectional view of the snare of  FIG.  12   a   , shown in an orientation similar to the sectional view of  FIG.  3     c;    
         FIG.  12   d    is a sectional view of the snare of  FIG.  12   a   , shown in an orientation similar to the sectional view of  FIG.  3     d;    
         FIG.  13    is a perspective view of the snare of  FIG.  3   , showing the snare in a deployed position; 
         FIG.  14    is a side view of a polyp on the mucosa layer of an intestinal wall; 
         FIG.  15    is a side view of the snare device of  FIG.  3    positioned around the polyp of  FIG.  14   , showing the snare in a position while in motion toward deployment; 
         FIG.  16    is a top view of  FIG.  15   ; 
         FIG.  17    is a side view of the snare device of  FIG.  3    positioned around the polyp of  FIG.  14   , showing the snare in a position while in motion toward retrieval; 
         FIG.  18    is a top view of  FIG.  17   ; and 
         FIG.  19    is an enlarged sectional view of the snare of  FIG.  3   , shown along the line  19 - 19  of  FIG.  18   . 
         FIG.  20    is a top view another snare having an irregular shape. 
     
    
    
     DETAILED DESCRIPTION 
     This Detailed Description merely describes exemplary embodiments in accordance with the general inventive concepts and is not intended to limit the scope of the invention or the claims in any way. Indeed, the invention as described by the claims is broader than and unlimited by the exemplary embodiments set forth herein, and the terms used in the claims have their full ordinary meaning. 
     The general inventive concepts will now be described with occasional reference to the exemplary embodiments of the invention. This general inventive concept may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the general inventive concepts to those skilled in the art. 
     Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art encompassing the general inventive concepts. The terminology set forth in this detailed description is for describing particular embodiments only and is not intended to be limiting of the general inventive concepts. As used in this detailed description and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. 
     Unless otherwise indicated, all numbers, such as for example, numbers expressing measurements or physical characteristics, used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless otherwise indicated, the numerical properties set forth in the specification and claims are approximations that may vary depending on the suitable properties sought to be obtained in embodiments of the invention. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the general inventive concepts are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical values, however, inherently contain certain errors necessarily resulting from error found in their respective measurements. 
     When generally discussing the invention and embodiments of the invention, the terms “portrait” and “landscape” will be used to described an orientation of an object. The term “portrait” and the term “landscape” have their common ordinary meaning, and are used in the same manner in which one would use each term to describe the orientation of a common and well-known object or thing, such as for example, a piece of paper or a picture frame. 
     Several limitations exist with conventional polypectomy removal techniques. Despite careful use, cauterization devices may cause serious thermal injury to the gastrointestinal wall, fail to remove the entire targeted tissue, or do not completely cauterize blood vessels which lead to excessive bleeding. Mechanical snare devices may also be difficult to operate, and a physician may experience difficulty in securing the targeted tissue with the snare. Also, snaring only the minimal tissue required from the three-layer wall, i.e., mucosa, submucosa, and muscularis, is also important. More specifically, to prevent complications, the muscularis tissue should be avoided in a mechanical snaring procedure. 
     An operator&#39;s attempt to minimize unwanted damaged to the removal site is complicated by a conventional snare. An operator of a snare may have difficulty in maintaining the snare in a flat position, that is to say, level or parallel with respect to the gastrointestinal wall, when closing the snare, and the desired tissue becomes more difficult to capture. A conventional snare tends to rise up and off the targeted tissue, or skim along the top of the tissue, when the snare is closing and moving in a proximal direction. As a result, either none or an inadequate amount of the targeted tissue is captured. Consequently, the snare has to be reopened and placed again on the distal side of the targeted tissue, and the process repeated until an adequate amount of tissue is captured. Furthermore, each opening and closing of the snare may lead to deformities in the snare. Such deformities may cause difficulties in fully opening the snare or may cause the snare to unexpectedly collapse during tissue capture. 
     Some physicians have used other techniques to improve results of a snare capture, especially on a first attempt. For example, some technicians use an endoscopic needle tool to inject saline into the targeted tissue. The injected saline increases the size of the targeted tissue, and in some cases, makes the tissue an easier target for a conventional snare process. This injection step adds time and cost, both labor and material, to the overall procedure. 
     The present application describes a tissue removal tool for use with an endoscope, such as for example, a snare suitable for use in removing a tissue sample, such as for example, a gastrointestinal polyp. The tool offers improved performance features, such as for example, moving the polyp into a raised and pinched position such that the polyp may be transected with a snare which remains in essentially a flat position. 
     The polyp may be advantageously manipulated in either the deployment direction, the retrieval direction, or both. The snare is formed by a wire, or similar structure, and arranged and shaped such to have a proximal portion and a distal portion in a deployed position. The proximal portion and a distal portion have different shapes in relation to each other, and specifically, in relation to the cross-sectional shape of one portion in relation to the cross-sectional shape of the other portion. The contrasting shape of one portion of the loop in relation to the other has surprising and previously unknown benefits. The proximal portion and the distal portion may be separated by a transition portion, in which the wire changes orientation, such as for example, is twisted, such that the cross-sectional shape of the wire is different in the proximal portion as compared to the distal portion. In other words, the piece of wire may have a cross-sectional height in the proximal portion unequal to a cross-sectional height in the distal portion. The wire may have a cross-sectional height in the proximal section equal to a cross-sectional width in the distal portion. Thus, in one of the deployment direction or the retrieval direction, the polyp is raised or pinched, and in the other of the deployment direction or the retrieval direction, the polyp is cut along a straight line relative the gastro-intestinal wall. 
     The snare may be shaped to perform the same or similar in other embodiments of the invention. The snare loop may be formed by a proximal portion, a distal portion, and a transitional portion separating the proximal portion and the distal portion. The piece of wire may be twisted by at least 45 degrees in the transitional portion on at least one side of the loop. As such, the piece of wire may have a cross-sectional height larger than a cross-sectional width in the proximal portion and a cross-sectional width larger than a cross-sectional height in the distal portion. Alternatively, the piece of wire may have a cross-sectional height smaller than a cross-sectional width in the proximal portion and a cross-sectional width smaller than a cross-sectional height in the distal portion. 
     In another embodiment of the invention, the shape of the loop may include portions which act as a memory point during opening and closing of the loop by motion of the handle relative the body. For example, the shape of the loop may be at least partially defined by a rotated and bent wire portion on either side of the loop, wherein the piece of wire has a cross-sectional height larger than a cross-sectional width at a location proximal to either rotated and bent wire portion and a cross-sectional height smaller than a cross-sectional width at a location distal to either rotated and bent wire portion. In one embodiment, the loop is polygon-shaped in the open position and the piece of wire is twisted essentially 90 degrees in the rotated and bent portion. 
     As discussed herein, the invention offers performance features related to preparing the polyp for removal. In one embodiment, the shape of the loop is defined by a distal portion and a proximal portion. The proximal portion has a distal facing vertical face and the distal position has a proximal facing edge. The wire forming the loop is twisted between the proximal portion and the distal portion, such that the distal facing vertical face of the proximal portion is higher than the proximal facing edge of the distal portion, and the top horizontal face of the distal portion is wider than a top horizontal face of the proximal portion. In deployment, the distal facing vertical face of the proximal portion pushes against the polyp. In retrieval, the proximal facing vertical edge of the distal portion cuts into the polyp as distal facing vertical face of the proximal portion prohibits movement of the polyp in the proximal direction. In other words, the proximal portion raises and pinches the polyp to prepare the polyp for transecting. Specifically, the proximal portion may increase the percentage of the polyp which is above a targeted cutting line, relative the gastro-intestinal wall. 
     A method of using an endoscopic tool to collect a tissue sample is also disclosed. The method includes placing a loop of an endoscopic tool adjacent a targeted tissue sample. The loop is formed by a piece of wire and is movable between a closed position and a deployed position by use of a tool handle. The distal facing vertical inward face of the proximal portion is higher than proximal facing inward edge of the distal portion. 
     In the performance of the method, the operator moves the loop from a closed position to an open position. In the open or deployed position, the distal facing vertical inward face of the proximal portion pushes against the targeted tissue sample. After full or otherwise desired deployment, the loop is moved from the open or deployed position to a closed position, such that the proximal facing vertical inward edge of the distal portion cuts into the targeted tissue sample. The method allows a snare to transect a polyp in the retrieval direction without the snare riding up the distal side of the polyp. A snare riding up the polyp may prohibit cutting the polyp along a straight line, or parallel line, relative the gastro-intestinal wall. 
     Referring now to the drawings, a retrieval device, or tissue removal tool is illustrated in  FIG.  1   . The tool is arranged for use with an endoscope to remove a tissue sample from the gastrointestinal wall of a human patient. The tool is also usable for other scientific purposes, and with a combination of other devices. This tool is illustrated and discussed for exemplary purposes only, and the invention may be practice with a tool having characteristics which vary from this tool. 
     The exemplary tool  10  includes a loop  12  formed by a piece of wire  14 . A wire of any suitable material may be used to form the loop, such as for example, a metal, such as stainless steel, or a plastic. The variations in the wire shape and orientation along the length of the wire may be made by mechanically twisting a preformed wire into the desired shape and orientation, of the wire may be originally manufactured to have the desired shape and orientation, such as for example, a preformed plastic piece. A suitable material will be flexible and have memory to allow deployment and retrieval of the loop. The wire forms a plurality of segments separated by collapse-resistant bends to define a loop opening. The loop is movable between an open position, or deployed position, and a closed position, or retrieved position. The loop  12  is illustrated in an open position in  FIG.  1   . The loop is polygon-shaped, and specifically, the loop is generally diamond-shaped. In  FIG.  2   , the loop  12  is shown in a closed position within a distal portion of the tool  10 . As discussed herein, the loop  12  is within a conduit  18 . In this closed or retrieved position, the exemplary loop has a length L 1 . 
     The tool may include a support assembly and a transmitting system for moving the loop between an open position and a closed position. In the exemplary tool  10  illustrated in  FIG.  1   , the support assembly includes a base or body  16  and an elongated hollow tube, tubular member or conduit  18 . The transmitting assembly includes a handle  20  movable relative to the body  16  and a link  22 . One end of the link is fixed to the handle and a second end is remote from the body. As shown in  FIGS.  1  and  2   , the link  22  extends substantially through a length of the conduit  18 . The conduit  18  may be any suitable, small-diameter tube formed of a non-reactive low-friction flexible material, such as for example, polytetraflourethylene. The conduit  18  defines a lumen with an opening at a distal second end  28 , as best seen in  FIG.  2    which shows a cross-sectional view of a distal portion of the tool  10 . A proximal first end  30  of the conduit is fixed to the body  16 . 
     The handle allows an operator to move the loop back and forth between a deployed position, as shown in  FIG.  1   , and a closed position, as shown in  FIG.  2   . Referring again to  FIG.  1   , the body  16  includes a fixed ring  24  at a proximal end. The handle  20  may be slid by an operator relative the body  16  by use of the handle  20 , and specifically, by use of one or both of two rings  26   a ,  26   b . The handle  20  is mounted over an elongated section of the body  16  and is movable relative to the body in the direction D 1  to deploy the loop  12 , or in an opposing direction D 2  to close the loop  12 . For example, an operator may place a finger in each of the rings  26   a ,  26   b  and a thumb of the same hand in the body ring  24 . By moving the two fingers in the direction D 1 , an operator can move the handle  20  relative to the body  16 . This movement of the handle will deploy the loop. In contrast, the handle  20  can be slid in the opposite direction D 2  by pulling one&#39;s fingers towards one&#39;s thumb to close the loop. 
     A link  22  is connected to the handle  20  for transferring axial motion from the handle  20  to other parts of the device. The link may be constructed of any suitable rigid material, and may be solid, hollow, or any suitable elongated object or combination of objects. The link may be one piece or formed from a series of pieces and connections, such as for example, hypodermic tubes, swage connections, and cables. The link  22  has a first end fixed to the handle  20  and a second end remote from the body  16 . As shown in the drawings, the link extends substantially through the conduit  18 . 
     Referring now to  FIG.  3   , a top view of the exemplary tool  10  of  FIG.  1    is shown in an open or deployed position. In the deployed position, the shape of the loop  14  may be discussed in relation to a longitudinal axis  A1  and a lateral axis  A2 . The longitudinal axis  A1  is defined along the longitudinal axis of the link  22  and the axis defines a first side of the loop  14   a ,  14   c  and a second side  14   b ,  14   d . The loop  12  is essentially symmetric relative the longitudinal axis  A1 . It should be apparent to those with skill in the art that the invention can be practiced with loops having a shape which are asymmetric relative the longitudinal axis  A1 , such as for example, the exemplary loops shown in  FIGS.  9   a    and  9   c.    
     The loop  12  has a proximal portion  12   a  and a distal portion  12   b  when in the deployed position. As shown in  FIG.  3   , the lateral axis A 2  defines, or separates, the loop into a proximal portion having two wire portions  14   a ,  14   b  and a distal portion having two wire portions  14   c ,  14   d . In this arrangement and relative to the lateral axis A 2 , the shape of proximal portion  12   a  is symmetric to the shape of the distal portion  12   b . It should be apparent to those with skill in the art that the invention can be practiced with loops having a shape which are asymmetric to the lateral axis A 2 , such as for example, the exemplary loops shown in  FIGS.  5 - 8 ,  9     a - 9   c  and  9   f.    
     The proximal portion and distal portion can also be defined relative a transitional portion. As shown in  FIG.  3   , a transitional portion  14   e ,  14   f  on either side of the loop  12  is disposed between the proximal portion  12   a  and the distal portion  12   b . An enlarged perspective view of the transitional portion  14   f  is illustrated in  FIG.  3   a   . Within the transitional area  14   f , the wire twists and turns. For discussion purposes, the wire  14  is discussed herein as traveling for the proximal portion  12   a  to the distal portion  12   b . Within the transitional portion  14   f , an entering portion  34   a  of the wire has a height greater than a width, in other words, the rectangular shape of the wire is in a portrait orientation. The bottom of the wire twists at a middle portion  34   b  inward along an axis of the wire, and the wire itself bends inward toward the longitudinal axis of the loop  12 . In the inventive tool, the wire is twisted at least 45° in a transitional portion on at least one side of the loop. In exemplary transitional portion  14   f  shown, the wire is twisted about 90°. As such, an exiting portion  34   c  of the wire  14   a  has width greater than a height, in other words, the rectangular shape of the wire is in a landscape orientation. 
     As discussed herein, the proximal portion and the distal portion are each formed from a wire  14 . The wire is orientated in the proximal portion in a different orientation than in the distal portion. In the exemplary loop  12  shown in  FIG.  3   , the wire  14  has a rectangular-shaped cross section. The cross-sectional shape of the wire  14 , relative to a horizontal plane during application, varies at different locations of the loop, as shown at different locations of the loop in  FIGS.  3   a - 3   f   . As discussed herein, the cross-sectional shape of the loop in the proximal portion relative to the cross-sectional shape of the loop in the distal portion contributes to the advantageous features on the tool  10 . 
       FIG.  3   b    is sectional view of the wire in the proximal portion  12   a  of the loop  12 , and shown along the line  3   b - 3   b  of  FIG.  3   . The wire has a height H 1  which is greater than the width W 1 . With the wire in an opposite orientation,  FIG.  3   c    is sectional view of the wire in the distal portion of the loop  12 . The wire is shown along the line  3   c - 3   c  of  FIG.  3   . The wire has a height H 2  which is less than the width W 2 . As such, the piece of wire having a cross-sectional height H 1  in the proximal portion equal to a cross-sectional width W 2  in the distal portion and unequal to a cross-sectional height in the distal portion H 2 . It would be apparent to one with skill in the art that the orientation of the wire in the proximal portion relative the distal portion could be reversed, in other words, the portrait orientation could be in the distal portion and the landscape orientation could be in the proximal portion in the practice of the invention, such as for example, as illustrated in the loops in  FIGS.  4 ,  7  and  8   . 
     Other sections of the loop will now be discussed. The loop  12  is formed by a wire  14  connected to the link  22 . The two ends on the wire  14  are fixed to the link  22  by any suitable technique, such as for example, by welding. As shown in  FIG.  3    and in the cross-sectional view in  FIG.  3   e   , the two end portions  38   a ,  38   b  are contiguous and each in a portrait orientation. A covering  36  is used to protect the connection between the wire and the link, and prohibit damage to the inside of the conduit  18 . 
     The most distal portions of the loop  12  is illustrated in  FIGS.  3   d  and  3   f   . In the exemplary loop  12 , the wire twists on each side of the loop near the distal tip  40  of tool. Referring now to  FIG.  3   f   , an enlarged version of one twisted portion is shown. Within the illustrated area, the wire twists and turns similar to the wire within a transitional portion  14   g . For discussion purposes, the wire  14  is discussed herein as traveling in the direction toward the distal tip  40 . Within the illustrated portion  14   g , an entering portion  42   a  of the wire has a width greater than a height, in other words, the rectangular shape of the wire is in a landscape orientation. The inward side of the wire twists at a middle portion  42   b  upward along an axis of the wire, and the wire itself bends outward away from the longitudinal axis of the loop  12 . As such, an exiting portion  42   c  of the wire  14   a  has height greater than a width, and the rectangular shape of the wire is in a portrait orientation. The wire continues toward the distal tip  40  to form a torsion tip having a 360° loop. 
     The distal tip  40  of the tool may have alternative shapes. The wire may form a torsion tip with a 180° bend, as shown in the exemplary loop of  FIG.  4   . In another distal tip, the wire within the 180° bend may be in a landscape orientation, as shown in the exemplary loop of  FIG.  5   . Still another distal tip is shown in the enlarged view of  FIG.  3   g   . In this exemplary distal tip, the loop is formed by a wire having two portions  44   a ,  44   b . The two wire portions are held together by a ball tip  44   c  at a distal most point. As assembled, the wire portions function as a loop the same as discussed herein. 
     A tool of the invention may have a loop having a variety of shapes, and a wire in more than one orientation. Other embodiments of the invention will now be discussed.  FIG.  4    is a top view of a loop, showing the loop in a deployed position. The loop  50  is in a polygon-shape, and specifically, is in a diamond shape. That is to say, the loop has the same general orientation about a longitudinal axis and a lateral axis A 2  as the loop illustrated in  FIG.  3   . Thus, the loop  50  has a proximal portion  12   a  and a distal portion  12   b  which are essentially the same in size. 
     As discussed herein, the wire  54  orientation in  FIG.  4    is generally reversed as compared to the wire orientation in  FIG.  3   . As shown in  FIG.  4   , a transitional portion  54   e ,  54   f  on either side of the loop  54  is disposed between the proximal portion  12   a  and the distal portion  12   b . An enlarged perspective view of the transitional portion  54   f  is illustrated in  FIG.  4   a   . Within the transitional area  54   f , the wire twists and turns. For discussion purposes, the wire  54  is discussed herein as traveling for the proximal portion  12   a  to the distal portion  12   b . Within the transitional portion  54   f , an entering portion  52   a  of the wire has a width greater than a height, in other words, the rectangular shape of the wire is in a landscape orientation. The bottom of the wire twists at a middle portion  52   b  outward along an axis of the wire, and the wire itself bends inward toward the longitudinal axis of the loop  50 . In exemplary transitional portion  54   f  shown, the wire is twisted about 90°. As such, an exiting portion  52   c  of the wire  54  has height greater than a width, and the rectangular shape of the wire is in a portrait orientation. 
     As discussed herein, the proximal portion and the distal portion are each formed from a wire  54 . The wire is orientated in the proximal portion in a different orientation than in the distal portion. In the exemplary loop  50  shown in  FIG.  4   , the wire  54  has a rectangular-shaped cross section. The cross-sectional shape of the wire  54 , relative to a horizontal plane during application, varies at different locations of the loop, as shown at different locations of the loop in  FIGS.  4   a - 4   e   . As discussed herein, the cross-sectional shape of the loop in the proximal portion relative to the cross-sectional shape of the loop in the distal portion contributes to the advantageous features on the tool  10 . 
       FIG.  4   b    is sectional view of the wire in the proximal portion  12   a  of the loop  50 , and shown along the line  4   b - 4   b  of  FIG.  4   . The wire has a width W 2  which is greater than the height H 2 . With the wire in an opposite orientation,  FIG.  4   c    is sectional view of the wire in the distal portion of the loop  12 . The wire is shown along the line  4   c - 4   c  of  FIG.  4   . The wire has a height H 1  which is greater than the width W 1 . As such, the piece of wire having a cross-sectional width W 2  in the proximal portion equal to a cross-sectional height H 1  in the distal portion and unequal to a cross-sectional width in the distal portion W 1 . 
     Other sections of the loop compare similarly to  FIGS.  3   b - 3   e   . In the cross-section show in  FIG.  4   e   , the wire portions  58   a ,  58   b  in the most proximal part of the loop as shown. The wire portions are connected to the link  22 . As shown in  FIG.  4    and in the cross-sectional view in  FIG.  4   e   , the two end portions  58   a ,  58   b  are contiguous and each in a landscape orientation. The most distal portion of the loop  12  is illustrated in  FIG.  4   d   . In the exemplary loop  50 , the wire bends outward on each side of the loop near the distal tip  56  of tool. The wire continues toward the distal tip  56  to form a torsion tip having a 180° loop, and the wire in a portrait orientation. 
     The invention may be practiced with a loop in which the proximal portion and the distal portion are not the same size.  FIGS.  5 - 8     e  shown four exemplary loops in which the proximal portion is not the same size as the distal portion. For example,  FIGS.  5  and  7    show a proximal portion in which the proximal portion is larger than the distal portion, and  FIGS.  6  and  8    show a proximal portion which is smaller than the distal portion. In these embodiments, all the loops are symmetric about a longitudinal axis of the link. In two of the loops,  FIGS.  5    and  6 , the wire is in a portrait orientation in the proximal portion, and in a landscape portion in the distal end. In the other two loops,  FIGS.  7  and  8   , the wire is in a landscape orientation in the proximal portion, and in a portrait orientation in the distal end. Each of these exemplary loops will now be discussed in some detail. However, properties of each loop can be identified by one with skill in the art by other discussions herein and by the Figures. 
     The loops illustrated in  FIGS.  5 ,  6 ,  7  and  8    are kite-shaped. In  FIG.  5   , the loop  60  is shaped and arranged such that a proximal portion  12   a  has a length L 4  which is greater than a length L 5  of the distal portion  12   b . Similarly, the loop  80  shown in  FIG.  7    is shaped and arranged such that a proximal portion  12   a  has a length L 8  which is greater than a length L 9  of the distal portion  12   b .  FIGS.  6  and  8    illustrate loops that have the same shape, but are arranged in a different orientation. In  FIG.  6   , the loop  70  is shaped and arranged such that a proximal portion  12   a  has a length L 6  which is less than a length L 7  of the distal portion  12   b . Similarly, the loop  90  shown in  FIG.  8    is shaped and arranged such that a proximal portion  12   a  has a length L 10  which is less than a length L 11  of the distal portion  12   b.    
     The loops illustrated in  FIGS.  5 ,  6 ,  7  and  8    also vary in the orientation of the wire. The loop  60  of  FIG.  5    and the loop  70  of  FIG.  6    have a wire  64 ,  74 , respectively, in which the wire in the proximal portion has a height greater than a width, that is to say, is rectangular shaped and in the portrait orientation. The wire  64 ,  74 , respectively, in the distal portion has a width greater than a height, that is to say, is rectangular shaped and in the landscape orientation. The wires of the loops  80 ,  90 , respectively, in  FIGS.  7  and  8    are in the opposite direction. The  FIGS.  5   a - 5   e ,  6   a - 6   e ,  7   a - 7   e  and  8   a - 8   e   , with reference characters relating to  FIGS.  5 ,  6 ,  7  and  8   , show the wire  64 ,  74 ,  84 ,  94 , respectively, at various points along the loop,  60 ,  70 ,  80 ,  90 , respectively, and clearly illustrated wire shape, wire orientation, wire twists, and wire bends. It should be apparent to one with skill in the art, that the loop embodiments illustrated in  FIGS.  5 - 8     e  are for exemplary purposes only, and other loop shapes and arrangements may be used in the practice of this invention. 
     A loop may have an irregular shape in the practice of this invention. For example,  FIG.  9   a    is a top view of another tool having an irregular shaped loop. The loop  100  is asymmetric about a longitudinal axis Au and is asymmetric about a lateral axis A 12 . The proximal portion  12   a  and the distal portion  12   b  are defined by two transitional points  102   a ,  102   b , in which the wire twists from a portrait orientation in the proximal portion  12   a  to a landscape orientation in the distal portion  12   b . A longitudinal axis A 13  of the distal end  104  is essentially perpendicular to the longitudinal axis A 11  of the link  22 . 
     Another exemplary loop having an irregular shape is shown in  FIG.  9   b   . The loop  110  is symmetric about a longitudinal axis A 14  and is asymmetric about a lateral axis A 15 . In this exemplary loop, the proximal portion  12   a  and the distal portion  12   b  are not divided by an axis which is perpendicular to the longitudinal axis of the link  22 . The proximal portion  12   a  and the distal portion  12   b  are defined by two transitional points  112   a ,  112   b , in which the wire twists from a portrait orientation in the proximal portion  12   a  to a landscape orientation in the distal portion  12   b . The distal end  114  is formed by a less than 180° bend of the wire in a landscape orientation. 
     Another loop which is polygon-shaped is illustrated in  FIG.  9   c   . The loop  120  is hexagon-shaped and is symmetric about a longitudinal axis A 16 , but is asymmetric about a lateral axis A 17 . The proximal portion  12   a  and the distal portion  12   b  are defined by two transitional points  122   a ,  122   b , in which the wire  122  twists from a portrait orientation in the proximal portion  12   a  to a landscape orientation in the distal portion  12   b . However, the wire maintains a landscape orientation as it bends inwards at two other points  122   c ,  122   d  along the hexagon shape. With the loop  120  in this arrangement, the proximal portion and the distal portion are not the same length. Specifically, the proximal portion  12   a  has length L 12  which is shorter than the length L 13  of the distal portion  12   b.    
     The distal portion of the hexagon-shaped loop  120  has similar properties to the loop illustrated in  FIG.  3   . At two transitional points  126   a ,  126   b , the wire  122  twists from a landscape orientation to a portrait orientation. In this portrait orientation, the distal end  124  of the loop  120  is formed by a less than 180° bend of the wire  122 . 
     Referring now to  FIGS.  9   d  and  9   e   , two oval-shaped loops are shown. In  FIG.  9   d   , an oval-shaped loop  130  has a wire  132  which includes a pattern of wire segments. The pattern is an alternating series of wire segments between a portrait orientation and a landscape orientation. The portrait orientation segments  132   b  and the landscape orientation segments  132   a  may be of different lengths, or may be of the same length, such as for example, 3 mm. A lateral axis A 18  defines, or separates, the loop  130  into a proximal portion  12   a  and a distal portion  12   b.    
       FIG.  9   e    shows an enlarged view of a wire having similar properties as the wire  132  of  FIG.  9   d   . The wire  142  illustrated in  FIG.  9   e    also is used to form an oval-shaped loop which includes a pattern on wire segments. The pattern is an alternating series of wire segments between a portrait orientation and a landscape orientation. The portrait orientation segments  142   b  and the landscape orientation segments  142   a  may be of different lengths, or may be of the same length, such as for example, 3 mm. The segments  142   a ,  142   b  are separated by a 360° loop  142   c . The wire  142  is in the portrait orientation within each loop  142   c , but the loop may be made in the landscape orientation. 
     The wires  132 ,  142  on  FIGS.  9   d  and  9   e   , respectively, may be used to construct a loop with advantageous properties. A loop constructed of either wire  132 ,  142  has a proximal portion and a distal portion, and each portion has segments in the portrait orientation and segments in the landscape orientation. As discussed herein, each particular orientation offers advantageous properties. Thus, the number and length of each particular segment type in the proximal portion and in the distal portion can be specified to produce desired performance characteristics of the tool. 
     Another loop having an irregular shape is shown in  FIG.  9   f   . This loop  150  is generally arrowhead-shaped. The loop  150  is divided into a proximal portion  12   a  and a distal portion  12   b  by two transitional portions  154   a ,  154   b . The wire  152  is in a portrait orientation in the proximal portion  12   a  and in a landscape orientation in the distal portion  12   b . At the distal end  156  of the loop  150 , the wire  152  maintains a landscape orientation. The distal end  156  is formed by a less than 180° bend of the wire  152 . 
     In the practice of this invention, a loop which is arrowhead-shaped may be polygon-shaped, or the loop may have curved portions. The loop  150  illustrated in  FIG.  9   f    is polygon-shaped, and is symmetric about the longitudinal axis A 19  and the lateral axis A 20 . 
     As discussed herein, the wire used to form a loop of this invention may be of different types of materials, and may be made by different manufacturing methods. Also, the wire may be of different cross-sectional shapes. Referring to  FIGS.  3  and  3     b , the exemplary wire  14  has a rectangular cross-section. Three other exemplary types of cross-sections are shown in  FIGS.  10   a - 12   d   . These three wire types, as well as wires having a cross-section not shown, may be used with any loop shape discussed herein. 
     Referring now to  FIGS.  10   a - 10   d   , a wire  200  with a diamond-shaped cross-section is illustrated. In  FIGS.  10   b  and  10   c   , the wire  200  is shown in a portrait orientation and in a landscape orientation, respectively. A distal end having a 360° bend formed from the wire  200  is shown in  FIG.  10   d   . A transitional portion of the wire  200  is shown in  FIG.  10   a   . In the transition portion, the wire  200  has an entering portion  202   a  in a portrait orientation, a center portion  202   b  in which the wire bends inward and twists °  90 , and an exiting portion  202   c  in a landscape orientation. 
     Referring now to  FIGS.  11   a - 11   d   , a wire  210  with an oval-shaped cross-section is illustrated. In  FIGS.  11   b  and  11   c   , the wire  210  is shown in a portrait orientation and in a landscape orientation, respectively. A distal end having a 360° bend formed from the wire  210  is shown in  FIG.  10   d   . A transitional portion of the wire  210  is shown in  FIG.  11   a   . In the transition portion, the wire  210  has an entering portion  212   a  in a portrait orientation, a center portion  212   b  in which the wire bends inward and twists °90, and an exiting portion  212   c  in a landscape orientation. 
     The wire shown in  FIGS.  12   a - 12   d    has a square-shaped cross-section. In other words, the wire  220  has a height H 1  which is equal to the width W 1 , as shown in  FIG.  12   b   . Because the wire has a square-shaped cross-section, the height of the wire is always equal to the width, at any particular orientation, such as for example, at an orientation turned 0° relative an application surface, such as shown in  FIG.  12   b   , or at an orientation turned 45° relative an application surface, such as shown in  FIG.  12   c   . A transitional portion of the wire  220  is shown in  FIG.  12   a   . In the transition portion, the wire  220  has an entering portion  212   a  in an orientation turned 0° relative an application surface, a center portion  212   b  in which the wire bends inward and twists °  45 , and an exiting portion  212   c  in an orientation turned 45° relative an application surface. 
     A method of use of the device  10  for removing a polyp from a gastro-intestinal wall of a patient will now be discussed. The  FIGS.  13 - 19    illustrate an exemplary method for removal and recovery of a polyp. It should be understood by others with skill in the art than other removal methods can be undertaken in the practice of the invention. 
     Referring to  FIG.  13   , a perspective view of the tool  10  of  FIG.  3    is shown with the loop in a deployed position. In this deployed position, or in another position, the tool  10  may be placed adjacent or around a targeted tissue.  FIG.  14    shows a side view of a polyp  300  on an intestinal wall. Specifically, the polyp is formed on the mucosa layer  302 , above the submucosa layer  304  and muscularis  306 . The polyp is shown at a relaxed height Hp above the top surface  310  of the mucosa layer  302 . As discussed herein, a polyp may be difficult to remove by cutting, especially along a target cut line on the first attempt. Further complicating such a procedure, a polyp may grow back if not transected at its base. In the exemplary method illustrated, the polyp may be cut along a target cut line  308 , which may be at a level even with the top surface  310  of the mucosa layer  302 . 
     Referring now to  FIG.  15   , an intubated endoscope  320  is shown adjacent the mucosa layer  302 . The distal portion of the tool  10  of  FIG.  13    is shown extending from an instrument channel of the endoscope to a location surrounding the polyp  300 . The conduit  18  is not shown for clarity. The loop  12  is shown in a deployed position after movement in a deployment direction D 1 . As a consequence of the deployment, the polyp  300  is manipulated by the proximal portion  12   a  of the loop  12 . As discussed with reference to  FIG.  3   , the proximal portion is formed by a wire having a rectangular-shaped cross-section and in a portrait orientation. As such, the wire  12  contacts the polyp in a plowing effect to pinch and raise the polyp relative the top surface  310  of the mucosa layer  302 . In a top view in  FIG.  16   , the wire is shown contacting the polyp along two lengths L 20 , L 21  of the proximal portion. 
     Referring again to  FIG.  15   , the plowing technique has the advantageous effect of pre-conditioning the polyp  300  for removal along the target cut line  308 . The polyp  300  is raised to a pre-conditioned height H X  in which a higher percentage of the mass of the polyp is above the target cut line  308 , and the center of gravity of the polyp  300  has been raised, each relative to the relaxed polyp condition shown in  FIG.  14   . The plowing also raised the amount of the polyp which is about the cutting face of the distal portion. 
     While the polyp is in the pre-conditioned position, the loop is manipulated in a retrieval direction D 2 . As a consequence of the retrieval, the cutting edge of the distal portion  12   b  of the loop  12  cuts into the polyp  300  at or near the target cut line  308 . As discussed with reference to  FIG.  3   , the distal portion is formed by a wire having a rectangular-shaped cross-section and in a landscape orientation. As such, the wire  12  contacts the polyp in a cutting effect to cut into the polyp as shown in  FIG.  17   . In a top view in  FIG.  18   , the wire is shown at a position during the cutting procedure with the distal portion contacting the polyp along two lengths L 22 , L 23 .  FIG.  19    shows an enlarged sectional view of the polyp along the line  19 - 19  of  FIG.  18   . As discussed, it should be apparent to one skilled in the art that other methods of use of the inventive tool are possible other than the exemplary method shown and discussed. 
     One more loop, which is polygon-shaped, is illustrated in  FIG.  20   . The loop  400  is symmetric about a longitudinal axis A 21 , but is asymmetric about a lateral axis A 22 . The wire  402  of the loop  400  includes, at its proximal portion  12   a , a first pair inward bends  404   a ,  404   b , followed distally by a second pair of inward bends  406   a ,  406   b . The wire  402  maintains a landscape orientation as it bends inwards at points  404   a ,  404   b ,  406   a  and  406   b . These additional bends (i.e., memory points) may help the loop  400  resist collapse and retain its shape over time. The proximal portion  12   a  and the distal portion  12   b  of the loop  400  are defined by two transitional points  408   a ,  408   b , in which the wire  402  twists from a portrait orientation in the proximal portion  12   a  to a landscape orientation in the distal portion  12   b.    
     The distal portion of the loop  400  has similar properties to the loop illustrated in  FIG.  3   . At two transitional points  410   a ,  410   b , the wire  402  twists from a landscape orientation to a portrait orientation. In this portrait orientation, the distal end  412  of the loop  400  includes a torsion tip having a 360° loop. While the loop  400  includes two bends in the proximal portion  12   a , other embodiments may include more bends in the proximal portion  12   a , distal portion  12   b , or both. Further, the addition of collapse-resistant bends may be used in conjunction within any other of the previously described embodiments. For example, a loop with at least two proximal bends may have an oval, arrowhead, diamond or kite shape (ignoring small variations from the proximal bends), may have wire with an oval or diamond cross-section, etc. 
     While various inventive aspects, concepts and features of the general inventive concepts are described and illustrated herein in the context of various exemplary embodiments, these various aspects, concepts and features may be used in many alternative embodiments, either individually or in various combinations and sub-combinations thereof. Unless expressly excluded herein all such combinations and sub-combinations are intended to be within the scope of the general inventive concepts. Still further, while various alternative embodiments as to the various aspects, concepts and features of the inventions (such as alternative materials, structures, configurations, methods, circuits, devices and components, alternatives as to form, fit and function, and so on) may be described herein, such descriptions are not intended to be a complete or exhaustive list of available alternative embodiments, whether presently known or later developed. Those skilled in the art may readily adopt one or more of the inventive aspects, concepts or features into additional embodiments and uses within the scope of the general inventive concepts even if such embodiments are not expressly disclosed herein. Additionally, even though some features, concepts or aspects of the inventions may be described herein as being a preferred arrangement or method, such description is not intended to suggest that such feature is required or necessary unless expressly so stated. Still further, exemplary or representative values and ranges may be included to assist in understanding the present disclosure; however, such values and ranges are not to be construed in a limiting sense and are intended to be critical values or ranges only if so expressly stated. Moreover, while various aspects, features and concepts may be expressly identified herein as being inventive or forming part of an invention, such identification is not intended to be exclusive, but rather there may be inventive aspects, concepts and features that are fully described herein without being expressly identified as such or as part of a specific invention. Descriptions of exemplary methods or processes are not limited to inclusion of all steps as being required in all cases, nor is the order that the steps are presented to be construed as required or necessary unless expressly so stated.