Abstract:
An endoluminal access system for accessing a body lumen, comprises a guide track which, when in an operative position, extends through a body lumen to a desired location therewithin and a modular device selectively coupleable to the guide track, the modular device including a drive mechanism for engaging the guide track to move the modular device along the guide track within the body lumen. A method of resecting tissue from a site within a body comprises the steps of inserting a guide track to a desired location within the body lumen, coupling a modular device to a proximal end of the guide track and actuating a motor mounted within the modular device to drive the modular device distally along the guide track to the site, drawing tissue at the site into the modular device in combination with the steps of coupling together a portion of tissue adjacent to the site, resecting the tissue from the site and actuating the motor to drive the modular device proximally to withdraw the modular device from the body lumen.

Description:
FIELD OF THE INVENTION 
     The present invention relates to the field of endoluminal access devices, and more particularly to endoluminal access devices driven by mechanical, electrical, and other like devices, and related methods of using such devices. 
     BACKGROUND OF THE INVENTION 
     Many endoluminal procedures are performed each year. Endoluminal procedures take place within tubes or lumens of the human body, such as vascular, gastrointestinal, or air exchange lumens, and generally involve the diagnosis and/or treatment of diseases and/or debilitating conditions. Endoluminal procedures generally involve use of a rigid or flexible tube such as an endoscope, which may be introduced into the human body through a body orifice, such as the mouth or rectum or through an incision. Endoscopes allow users to view intended internal treatment sites and may provide one or more working channels, or pathways, to the treatment site. 
     Endoscopes may be manually steered or positioned through the body until the endoscope is properly positioned. For some devices used to remove tumors and polyps, e.g., full thickness resection devices (FTRDs), accurate positioning is important to successful use. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention is directed to an endoluminal access system for accessing a body lumen, comprising a guide track which, when in an operative position, extends through a body lumen to a desired location therewithin and a modular device selectively coupleable to the guide track, the modular device including a drive mechanism for engaging the guide track to move the modular device along the guide track within the body lumen. 
     The present invention is further directed to a method of resecting tissue from a site within a body comprising the steps of inserting a guide track to a desired location within the body lumen, coupling a modular device to a proximal end of the guide track and actuating a motor mounted within the modular device to drive the modular device distally along the guide track to the site, drawing tissue at the site into the modular device in combination with the steps of coupling together a portion of tissue adjacent to the site, resecting the tissue from the site and actuating the motor to drive the modular device proximally to withdraw the modular device from the body lumen. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments of the invention and together with the description, serve to explain the principles of the invention. In the drawings, 
         FIG. 1  is a perspective view of an access device according to an embodiment of the present invention; 
         FIG. 2  is a partial cross-section view of the access device of  FIG. 1 ; 
         FIG. 3  is a cross-section view of another embodiment of an access device according to the present invention; 
         FIG. 4  is a cross-section view of a further embodiment of an access device according to the present invention; 
         FIG. 5A  is a side view of a still further embodiment of an access device of the present invention in a first configuration; 
         FIG. 5B  is a side view of the device of  FIG. 5A  in a second configuration; 
         FIG. 5C  is a side view of the device of  FIG. 5A  in a third configuration; 
         FIG. 5D  is a side view of the device of  FIG. 5A  in a fourth configuration; 
         FIG. 6A  is a perspective view of an external drive shaft according to an embodiment of the present invention; 
         FIG. 6B  is a cross-section view of the drive shaft of  FIG. 6A ; 
         FIG. 6C  shows a side view of an additional embodiment of an access device according to the present invention including a drive shaft as shown in  FIGS. 6A and 6B ; 
         FIG. 7A  is a cross-section view of a proximal portion of a modular device for use in the access device of  FIGS. 5A-5D ; 
         FIG. 7B  is a cross-section view of a proximal portion of the modular device of  FIG. 7A  taken at line B-B of  FIG. 7A ; 
         FIG. 7C  is a cross-section view of the proximal portion of the modular device of  FIG. 7  taken at line C-C of  FIG. 7A ; 
         FIG. 8A  is a cross-section view of a distal portion of the modular device of  FIG. 7A ; and 
         FIG. 8B  is a cross-section of the distal portion of the modular device of  FIG. 7A  taken at line B-B of  FIG. 8A . 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to the present exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. 
     According to the present invention, an endoluminal access system includes a modular device containing tools for performing an internal procedure or treatment. The modular device may be moved within a body lumen, for example, along a guidewire inserted thereinto without an endoscope. The modular device may optionally include an internal or an external power source driving the modular device along the guidewire. 
     The use of a guidewire to direct the device to the treatment site rather than an endoscope may make access to internal treatment sites less time consuming and may reduce trauma to the body tissues associated with the insertion of an endoscope. A guidewire may be inserted into the body lumen and directed to the treatment site by methods known in the art. The modular device may then be slidably coupled to the guidewire and moved therealong to the treatment site. If the modular device is coupled to a powered drive mechanism, there will be no need for an operator to push or force the modular device into the body lumen. Body tissues/lumens may be required give way as the modular device moves along the guidewire. However, these tissue do not remain in a stretched or expanded state as long as is required for an endoscope which will extend along the entire distance from the point at which the endoscope enters the body to the treatment site. In contrast, only that portion of the tissue currently in contact with the modular device may be impacted while the rest of the tissue between the treatment site and the opening to the body lumen will be occupied only by the small diameter guide wire. Thus, trauma to surrounding tissue may be reduced. In addition, depending on the number and nature of the tools required for a certain procedure, the modular device employed may be smaller in diameter than a standard endoscope. This may further reduce trauma to surrounding tissue. 
     In addition, as described below, the driving mechanism of the modular device and an optional viewing device, make it-is possible to accurately position the modular device. The accuracy in positioning may reduce the time required for the treatment and may also reduce risk of erroneously treating the wrong area. 
     According to the present invention and as embodied in  FIG. 1 , an endoluminal modular access system  100  is provided. System  100  may generally include a modular device  110 , a track  120  for guiding/moving the modular device  110 , and a drive mechanism  112  for driving the modular device  110  along the track  120 . Each of these general portions of system  100  will be described in detail below. 
     As embodied herein and shown in  FIG. 1 , a modular device  110  for traveling within a body lumen  103  may vary in size and shape dependent upon the size and type of tools required for a given procedure and contained therewithin and/or the size and shape of the body lumen in which it is to be used. The exterior of modular device  110  may optionally include a hydrophilic coating to facilitate passage through the body lumen  103  and may preferably have rounded edges to facilitate movement within the body lumen  103 . Modular device  110  also includes holes  117   a ,  117   b  formed in the proximal and distal ends, respectively, of the modular device  110  for receiving the guide track  120  as described in detail below. 
       FIG. 2  shows an embodiment of a drive mechanism  112  which may be provided in modular device  110 . As shown in  FIG. 2 , the drive mechanism  112  includes a motor  115  engaging a guide track  120 . Motor  115  is contained within modular device  110  and may be connected via a cable  135  to an external power source and control box  140 . Cable  135  extends from modular device  110  to the power source and control box  140  which is located externally of the patient. In this embodiment, motor  115  is connected to gear wheels  130  so that gear wheels  130  rotate when powered by the motor  115 . Control box  140  enables a user to determine a direction of rotation of gear wheels  130  and may also allow a user to control a speed of rotation thereof. When rotated in a first direction, gear wheels  130  draw the modular device  110  distally along the guide track  120  into the lumen of the body of the patient and away from the operator. When rotated in the second direction, the gear wheels  130  draw the modular device  110  proximally along the guide track  120  toward the external opening of the lumen of the patient and toward the operator. 
     Those skilled in the art will understand that various known suitable sources of power and various known suitable devices for controlling the source of power, movement and operation of the modular device  110  may be employed. For example, the power source may be a battery device, or a source of air or hydraulic pressure such as a pneumatic or hydraulic pump. In addition, although  FIG. 2  shows the use of three gear wheels  130 , those skilled in the art will understand that any suitable number and type of gear wheels or other like device may be employed to grip track  120  and move the modular device  110  therealong. For example, a continuous belt may frictionally engage the guide track  120  so that rotation of the belt drives the modular device  110  therealong. The invention is not to be limited to any particular power supply or controller, or drive mechanism type. 
     As embodied herein and shown in  FIGS. 1 and 2 , modular device  110  moves along a guide track  120 . Guide track  120  may be, for example, a straight guidewire or shaft, a catheter, a coiled guidewire or metal shaft, or any like device. Guide track  120  is intended to be inserted into the lumen  103  of the patient toward the desired treatment site prior to the insertion of the modular device  110  using known techniques. The guide track  120  may then optionally be anchored within the lumen at a desired location relative to the treatment site. A proximal end of the guide track  120  is then inserted into the hole  117   b  and the modular device  110  is driven distally along the guide track  120  until the proximal end of the guide track  120  exits the hole  117   a . Further advancing the modular device  110  distally along the guide track  120 , the operator then guides the modular device  110  into the opening to the body lumen and advances the modular device  110  distally to the treatment site. 
     In the embodiment shown in  FIG. 2 , gear wheels  130  engage guide track  120 , which may be formed, for example, as a straight guidewire or flexible shaft. Gear wheels  130  are powered by the motor  115  which is powered by the external power supply. If a forward direction is selected on the control box, the gear wheels  130  will rotate and grip track  120  such that modular device  110  moves in a forward, distal direction along track  120 . If a reverse direction is selected, the modular device  110  moves in a rearward, proximal direction along track  120 . In addition to direction control, control of the speed of the modular device  110  may be provided so that, for example, modular device  110  can be more quickly moved to the treatment site, and have its position fine-tuned at lesser speeds. The speed of modular device  110  may be dictated by considerations of safety to the patient and the capability of the power source and drive device. 
       FIG. 3  shows another embodiment of a drive mechanism  112  provided in modular device  110 . In this embodiment, an electric motor  115  is again provided inside modular device  110 . Those skilled in the art will understand that the motors employed in connection with any of the embodiments of this invention need not be electric motors. Alternatively, as would be understood by those of skill in the art, the functions of all of these motors may be provided by fluid powered motors such as air/hydraulic motors. Such motors may be run in two directions by, for example, including two separate fluid supply lines, one of which is to be engaged for a first direction of rotation of the motor with engagement of the second operating the motor in the opposite direction. Motor  115  is powered as described above, and is connected to a gear set  130   a . Gear set  130   a  is positioned within modular device  110  to engage guide track  120   a , which is embodied as a coiled guidewire or shaft. At least one portion of modular device  110  which contacts and sits on guide track  120   a  includes a threaded portion to allow modular device  110  to move along coiled guide track  120   a . The threaded portion is preferably a threaded hole  117   b  in an end of modular device  110  which intermeshes with the coils of track  120   a . Gear set  130   a  engages the coiled guide track  120   a , and when powered, gear set  130   a  moves along the coils of guide track  120   a  to move modular device  110  in either a forward (distal) or reverse (proximal) direction. 
       FIG. 4  shows a further embodiment of a drive mechanism  112  provided in modular device  110 . In this embodiment, an electric motor  115  is provided inside modular device  110 . The motor  115  may be powered as described above, and includes a rotor  132  and stator  134  arrangement, as would be understood by those of skill in the art. The rotor  132  is positioned within the stator portion  134  and includes a central threaded portion. Rotor  132  is positioned within the modular device  110  to engage and rotate about guide track  120   b , which is embodied as a coiled guidewire or shaft. As shown in  FIG. 4 , the coils of the guide track  120   b  provide a substantially helical threaded surface which is engaged by the corresponding threaded portions  111   a ,  111   b  of the lumen extending through the modular device  110  through which the guide track  120   b  passes are formed at the proximal and distal ends of the modular device  110 . Contact between these threaded potions  111   a ,  111   b  and the guide track  120   b  as the modular device  110  is rotated by the electric motor  115  moves the modular device proximally or distally therealong depending on the direction of rotation. Those skilled in the art will understand that the rotor  132  may optionally be nonrotatably coupled to the threaded portions  111   a ,  111   b  while a radially outer portion of the modular device  110  is rotatably coupled to the rotor  132  and the threaded portions  111   a ,  111   b  so that this radially outer portion may maintain a substantially constant angular orientation relative to the guide track  120   b  as the modular device  110  is moved therealong. 
     Furthermore, as shown in  FIGS. 5A-5D , the endoluminal modular access system  100  may also include an anchor module  150  to anchor a portion of the guide track  120   b  (e.g., the distal end thereof) at a desired location within the body lumen  103  so that the modular device can be more easily advanced along guide track  120   b . The anchor module  150  may preferably contain a motor (e.g., a servo screw motor) (not shown) which, when powered, moves the anchor module  150  along the guide track  120   b  in a manner similar to that described in regard to the motion of the modular device  110  along the guide track  120 . Furthermore, those skilled in the art will understand that any suitable motor or other like drive device may be used to power the anchor module  150 . For example, the anchor module  150  may utilize any of the drive devices and activators described in connection with the modular devices  110  of this invention. The anchor module  150  preferably has rounded edges to minimize trauma to body tissue and to ease movement of the anchor module  150  through the body lumen. An anchoring extendible member  152  is provided on the anchor module  150  which may be configured in a first radially compressed state for insertion and retraction from the patient&#39;s body and a second radially expanded state in which the extendible member  152  contacts the wall of the body lumen  103  to anchor itself and the guide track  120  in place. Those skilled in the art will understand that the expandable member may be an extendible cage or arm or, as shown in  FIGS. 5A-5D , a balloon. Furthermore, those of skill in the art will understand that the anchoring module  140  may include more than one extendible member  152  to aid in stabilizing the anchor the module  150  in position. In use, the anchor module  150  is preferably deployed when the distal end of the guide track  120  is brought to the desired location within the body lumen  103  prior to the insertion of the modular device  110  into the body lumen. The motor within the anchor module  150  may engage the guide track  120   b  in any manner similar to those described in regard to the modular device  110  (e.g., a gear or belt drive, threaded holes engaging a helical thread of the guide track  120 , etc.). 
     Once at the distal end of the track  120   b  has reached the desired location within the body lumen  103 , the extendible member  152 , is actuated. For example, for a balloon extendible member  152 , the operator supplies fluid to the balloon via the tube  156  to expand the balloon until it contacts the wall of the body lumen  103 . To do this, the operator connects the tube  156  to a suitable source of fluid preferably external to the patient&#39;s body. The balloon of extendible member  152  expands until it contacts and pushes against the walls of the body lumen. Thus, extendible member  152  anchors itself within the body lumen and because it is anchored, it stabilizes the track  120   b  for the modular device  110 . 
     In this preferred embodiment as shown in  FIG. 5D , the modular device  110  may also include an extendible member  154 , (e.g., a positioning balloon) for stabilizing the position of the module device  110  during the procedure to enable optimal use of the tools contained therein. The extendible member  154  may be arranged such that, when in the extended configuration, pushes the modular device  110  into contact with one side of the lumen  103  (e.g., the side of the lumen on which the tissue to be treated is located). The extendible member  154  is supplied with an inflation fluid (e.g., air or saline) via an inflation lumen (not shown) which is preferably separate from that used to inflate from the tube  156  which is used to inflate the balloon extendible member  152 . 
     In a further embodiment of an endoluminal modular access system, the modular device  210  may be a full thickness resection device (FTRD). The function of an FTRD is to remove a full thickness section of tissue from an organ and reseal the opening created through the resection. The FTRD modular device  210  is shown in  FIGS. 5C and 5D  and  FIGS. 7A ,  7 B,  7 C,  8 A and  8 B. 
       FIG. 7A  shows a cross-section of a proximal portion of the FTRD modular device  210 . As can be seen in  FIG. 7A , FTRD modular device  210  includes an outer casing  202 , and a central motor  215 . Outer casing  202  is preferably smooth, and formed of a biocompatible material such as a biocompatible plastic or metal, as would be understood by those of skill in the art. Furthermore, the outer casing  202  may include a hydrophilic coating. The outer casing  202  is preferably oval or circular in cross-section with blunt, rounded ends. Other shapes such as, for example, a rectangular cross-section with rounded corners may also be used. The size of the outer casing  202  is preferably between 2 and 10 cm in length with a circumference (or perimeter) of between 3 and 19 cm. As would be understood by those of skill in the art, the size of the outer casing  202  may vary based upon the type and size of the tools required for a particular procedure and which are contained within the outer casing  202 . Motor  215  may preferably be a direct current electric motor which may be driven in two directions. Motor  215  includes outer windings  215   a  which are stationary and attached to outer casing  202  and an armature formed as a sleeve  215   b  having a central lumen extending therethrough. A guide track, e.g., in the form of a catheter  220  may be slidably received in the central lumen of the armature sleeve  215   b  with the armature sleeve  215   b  rotating thereabout when the motor  215  is driven to move the FTRD modular device  210  along the catheter  220  via the drive mechanism described below. 
     As shown in  FIGS. 7A and 8A , the drive mechanism  112  provided in the FTRD modular device  210  includes proximal and distal sets of roller gears  230   a ,  230   b  positioned around the catheter  220  proximally and distally of the armature sleeve  215   b , respectively. When in an unpowered state, roller gears  230   a ,  230   b  are moved out of engagement with the catheter  220 . However, when power is supplied to the motor  215 , the roller gears  230   a ,  230   b  are firmly pressed against the catheter  220  to engage catheter  220  so that rotation of the roller gears  230   a  and  230   b  draws the FTRD modular device  210  along the catheter  220  either distally or proximally, depending on a direction of rotation of the motor  215 . 
     Roller gears  230   a ,  230   b  are powered by armature sleeve  215   b  through armature sleeve gear  215   c  and roller takeoff gear  232 . Roller takeoff gear  232  is connected to roller gears  230   a ,  230   b  through a shaft  234 . Roller gears  230   a ,  230   b  are moved into and out of contact with the catheter  220  by pressers  240  which are moved radially inward when the motor  215  is powered contact the roller gears  230   a ,  230   b  to press the roller gears  230   a ,  230   b  into contact with the catheter  220 . When power is withdrawn from the motor  215 , the pressers  240  are moved radially outward to remove the inward pressure on the roller gears  230   a ,  230   b . The roller gears  230   a ,  230   b  are biased radially outward by a biasing member (not shown) so that, when the pressers  240  are moved out of contact therewith, the roller gears  230   a ,  230   b  are automatically withdrawn from contact with the catheter  220 . Pressers  240  are shifted radially by longitudinal pressers  245  which are moved longitudinally into and out of contact with the pressers  240  by an electrically powered linear transducer  247 . As would be understood by those of skill in the art, transducer  247  may be an electrically charged magnetic solenoid configured to apply linear force to the longitudinal pressers  245 . Alternatively, transducer  247  may be replaced by a hydraulic piston. 
     As embodied herein and shown in  FIGS. 7A and 8A , FTRD modular device  210  includes a grabbing element  260  having end grippers  262  for grabbing a selected tissue sample and pull the tissue into a tissue receiving chamber  264   a  formed within the FTRD modular device  210 . Grabbing element  260  is mechanically controlled by manipulation of an actuator which remains external to the patient and which is connected to a proximal end of grabbing element  260  by, for example, a control cable, flexible drive shaft, hydraulic line, as would be understood by those of skill in the art. Furthermore, any of various known suitable actuators may be used to allow the operator to control the grabbing element  260 . In an alternative embodiment, grabbing element  260  may be replaced with a vacuum grabber for drawing the selected tissue into the tissue receiving chamber  264   a  as would be understood by those of skill in the art. 
     As embodied herein and shown in  FIGS. 7A and 8A , a cutting element  266 , which may, for example, be in the form of a curved blade having a cutting surface extending at an angle relative to a longitudinal axis the FTRD modular device  210 , in an operative configuration extends into the tissue receiving chamber  264   a . Cutting element  266  is operated after the selected portion of tissue has been stapled as described below to cut the selected portion of tissue away from the body lumen so that it may be retained within the tissue receiving chamber  264   a . A linear transducer  272  engages and disengages a cutter engaging element  270 . After FTRD modular device  210  has reached a desired position, the actuator  247  is released to disengage roller gears  230   a ,  230   b  thereby preventing further movement of the FTRD modular device  210  along the catheter  220 . 
     A window formed in the outer casing  202  is covered by clamping element  274 . The window may then be opened, as shown in  FIG. 8A , by activating a linear transducer  276  which is coupled to the clamping element  274 . The linear transducer  276  may be controlled by, for example, an electric solenoid or fluid powered cylinder as would be understood by those of skill in the art. A selected portion of the tissue is drawn into the tissue receiving chamber  264   a  using the grabbing element  260  and operator controls the linear transducer  276  to move the clamping element  274  into the closed position adjacent the anvil  264  to close the window and clamp the tissue between the anvil  264  and the clamping element  274 . The anvil  264  is driven by a hammer  280  to form the staples, as described below to staple to tissue, as described below and, after this stapling has been completed, the actuator  272  is powered and a drive train is established between drive gears  215 D, an idler gear  217  on the end of actuator  272 , and cutter gear  270  to begin movement of the cutting element  266  to sever the tissue radially within the stapled tissue. As the connection between the roller gears  230   a ,  230   b  has been removed, the motor  215  may be driven to actuate the cutting element  266  without driving the FTRD modular device along the catheter  220 . 
     When linear transducer  272  engages the cutter engaging element  270 , a cutter sleeve armature gear  215 D is activated by cutter engaging element  270 . Cutter sleeve armature gear  215 D, in turn, causes rotation of a cutter take up gear  268  which rotates cutting element  266 , causing it to cut the selected tissue sample. Structural members extend between the transducers  247 ,  276  to support them and the tissue receiving chamber  264   a  extends between an anvil  264  (which forms staples) and the clamping element  274 . 
     Also provided in FTRD modular device  210  is a stapler hammer  280 . Stapler hammer  280  inserts staples  278  into the clamped tissue. Stapler hammer  280  is spring loaded and actuated by manual release of the spring  282 . A manual release trigger is controlled by the operator through manipulation of an actuator external to the patient to actuate the stapler hammer  280  to insert staples  278  into the tissue. Spring  282  may be actuated, for example, when released via a mechanical cable from a compressed state. As would be understood by those of skill in the art, although element  282  is shown as a spring, other devices such as the actuators previously described may be used. Alternatively, instead of or in addition to the FTRD modular device  210 , other devices such as cutters, tissue cauterizing devices, graspers, biopsy devices, etc., may be contained within the modular device  210 . Additionally, the device may be actuated by other means such as remote control or under computer control. 
     A preferred method of using an endoluminal modular access device according to one embodiment of the present invention will now be described with reference to  FIGS. 5A-5D . First, a guide track  120   b  is selected and inserted by the operator into a body lumen  103  of the patient&#39;s body. Selection of an appropriate guide track  120   b  may depend on the size and characteristics of the body lumen, the corresponding size of the modular device  110 , the types of tools contained within the modular device  110  and/or required for the particular procedure to be performed and which would effect the weight of the modular device  110 , and the characteristics of the power source being used to drive the modular device  110  along the track  120   b . After the guide track  120   b  has been inserted into the modular device  110 , a distal end of the guide track  120   b  is advanced to the treatment site and anchored to a desired location at or near the treatment site as would be understood by those of skill in the art. For example, an anchor module  150  may be placed on the guide track  120   b  and advanced by actuation of, for example, a servo screw motor within the anchor module  150 . The anchor module  150  may then be advanced to the distal end of the guide track  120   b  and, at this point, an extendible member  152  is expanded, e.g., by supplying inflation fluid to a tube  156  to inflate an anchoring balloon of the extendible member  152  thereby anchoring the guide track  120   b  at the desired position within the body lumen  103 . Those skilled in the art will understand that the modular device  110  need not be coupled to the guide track  120   b  before the distal end thereof is anchored at the desired location. Alternatively, after the distal end of the guide track  120   b  has been anchored in place, the modular device  110  may be advanced over the proximal end of the guide track  120   b  into the body lumen  103 . 
     Once guide track  120   b  has been anchored within body lumen  103 , modular device  110  is attached to guide track  120   b  at the proximal end of guide track  120   b  external to the patient. Modular device  110  is then advanced along guide track  120   b  toward the distal end thereof and is positioned within the body lumen  103 . If desired, when the device has reached a desired position within the body lumen  103 , the extendible member  154  may be deployed by an operator, e.g., by introducing fluid to the tube  156  which extends to the extendible member  154 , in order to push modular device  110  into a position adjacent the wall of lumen  103 . 
     For example, in the case of the FTRD modular device  210 , a window is provided in the outer casing  202  of FTRD modular device  210  through which a grabbing element  260  and grippers  262  may be extended to grab and retrieve a selected portion of tissue when the clamping element  274  has been moved to an open position away from the window. The selected tissue sample is then pulled into the tissue receiving chamber  264   a  (i.e., the space between the anvil  264  and the clamping element  274 ). As described above, once the selected tissue sample has been drawn into the tissue receiving chamber  264   a , the actuator  276  is operated to move the clamping element  274  into the closed position clamping the tissue against the anvil  264 . When clamped into the tissue receiving chamber  264   a , the selected portion of tissue should be folded over so that a portion of tissue twice the thickness of the organ is clamped between the clamping element  274  and the anvil  264  (i.e., the clamping element  274  contacts an inner surface of a first portion of the wall of the organ with an outer surface of the first portion of the organ contacting an outer surface of a second portion of the organ and an inner surface of the second portion of the organ contacts the anvil  264 . The gripper  262  may then be released and withdrawn. The hammer  280  is then operated to drive staples through the full thickness of the tissue of the first and second portions of the organ with the staples being formed against the anvil  264 . After completing the stapling, the cutter element  266  is actuated and begins rotating through the selected portion of tissue to cut this tissue from the wall of the body lumen  103 . Because the full thickness of the tissue of the first and second portions of the organ has been stapled together, cutting away that portion of tissue received radially within the stapled portion leaves the organ sealed. After the cutting has been completed, the extendible member  154  is deflated, and the FTRD modular device  210  is driven in reverse (i.e., proximally) along guide track  120   b  toward the external opening of the lumen. When the FTRD modular device  210  has been removed from the body lumen  103 , the extendible member  152  is deflated, and the anchor module  150  is also driven along guide track  120   b  proximally to the external opening of the body lumen  103 . Once the extendible member  152  has been removed from the body lumen  103 , the guide track  120   b  is withdrawn therefrom by the operator, and if necessary, the external opening to the body lumen  103  is surgically closed. 
     Alternatively, as shown in  FIGS. 6A ,  6 B and  6 C and described further herein, an alternate drive mechanism including a drive-shaft  320  which extends from the modular device  110  through the body lumen and out of the body where it may be coupled to a power source (not shown). Those skilled in the art will understand that the modular device  110  according to this embodiment may be substantially similar to those of the previously described embodiments, except that no motor or other power source is located therewithin. Rather, motive power is transmitted to the modular device from the external power source via the drive shaft  320 . The drive shaft  320  extends into the modular and couples to a drive mechanism (not shown) which may be constructed in accord with any of the previously described embodiments. Specifically, the drive shaft  320  includes a thick outer shell  321  with an inner gear  322  being rotatable within the outer shell  321  when driven by the external power source. The outer shell  321  is removed from a distal end of the drive shaft  320  to expose the inner gear  322  so that the inner gear may engage the drive mechanism. As would be understood by those of skill in the art, the modular device  110  may further include a slip clutch and a cable which connects to the drive shaft  320  or other suitable drive mechanism to move modular device  110  along the guide track  120  as the drive shaft  320  is rotated. 
     Those skilled in the art will understand that the described exemplary embodiments of the invention may be altered without departing from the teaching of the invention, e.g., by replacing the spring actuation of the stapler or the linear transducer actuators described by pneumatically actuated mechanisms. Thus, it is to be understood that these embodiments have been described in an exemplary manner and are not intended to limit the scope of this invention which is intended to covers all modifications and variations of this invention that come within the scope of the appended claims and their equivalents.