Flexible, selectively rotatable tissue retractor and method for using the retractor

A retractor for manipulating an object, the retractor includes a retractor body with proximal and distal ends, a retraction device with a head connected at the distal end of the retractor body and flexible needles of a shape memory material having a memory shape, the memory shape of the needles including a portion with an arcuate shape housed, at least partially, within the head. The retractor further includes an actuation device connected to the proximal end of the retractor body and operatively connected to the needles, the actuation device, upon actuation thereof, moving the needles out of the head and withdrawing the needles into the head and a rotation joint allowing the distal end of the retractor body and the retraction device to rotate independent of the proximal end of the retractor body.

FIELD OF THE INVENTION

The present invention relates to a tissue retractor, especially a flexible tissue retractor used as an endoscopic device that is passed through a working channel of a flexible endoscope. The tissue retractor has application in endoscopic and open surgery, including flexible endoscopy, laparoscopy, and general surgery. It can be made rigid or flexible and in lengths and diameters to suit the requirements of the surgical field. The flexible endoscopic tissue retractor is used to hold gastrointestinal tissue so that it can be retracted or manipulated in some way. The tissue retractor can be configured to allow grasping of specific layers of the gastrointestinal wall by adjusting the shape and/or length of the needles and their exit points at the tip of the device. For example it can be configured to grasp through the mucosal layer, and into the muscular layer, thus providing a more secure connection to the tissue and allowing manipulation of the entire thickness of the tissue. Alternately, it can be configured to grasp the mucosal layer allowing manipulation of the mucosal layer only.

BACKGROUND OF THE INVENTION

A number of conventional devices exist in the prior art, which devices are used to manipulate the tissue during the endoscopic surgical procedure for treatment of Gastroesophageal Reflux Disease (GERD).

For example, U.S. Pat. No. 6,494,888 B1 to Laufer et al. (referred to hereinafter as “Laufer”) describes an instrument for reconfiguring stomach tissue. A tissue manipulator 700 includes an elongated cable assembly 716 and a distal end effector 718 actuated by the cable assembly 716 to perform various steps in the tissue reconfiguring procedure. See Laufer at FIGS. 9A to 9F. The end effector 718 has two jaw members 720, 722 that engage tissue, in particular, tissue at the gastroesophageal junction (GEJ). During the process of implanting the two-part fastener 732, 734 (see Laufer at FIG. 8), a coil 740 is rotated into the GEJ tissue and, after being screwed therein to a sufficient extent, is used to pull the GEJ tissue between the opening defined by the two jaw members 720, 722 in an open position illustrated, for example, in FIGS. 9D and 9E. The coil tissue puller 740, 741, 742 is shown, in particular, in FIG. 3D. The puller has certain disadvantages, however. The coil 740 can penetrate too far, causing possible negative consequences if the stomach is entirely breached (through the mucosa, muscularis, and serosa layers). Because the aorta, liver, diaphragm and other vital organs are disposed adjacent to the fundus of the stomach, if the coil 740 passes through the serosa, there is a significant chance of damage to the vital organs. Also, upon withdrawal, the coil 740, due to its inherent shape, can become stuck in the tissue and, thereby, cause damage to the tissue when the user must forcefully retract the entire assembly 718. Depending on the angle of entry, it is possible that the coil 740 only enters the mucosa. If this occurs, because the mucosa is a relatively thin, loosely attached layer, there is a high probability that the fastener 732, 734 will be only implanted in the mucosa and, therefore, result in a failed implantation procedure. Also, for fasteners that coil into the tissue, the tissue is compressed disadvantageously because rotation of the coil can twist the tissue as the coil is threaded in, which twisting can damage the tissue and cause it to weaken. Also, to advance the coil into the tissue, the coil must be rotated. It is inherently more difficult to transmit torque through a slender flexible device than it is to transmit thrust loads, thus, pushing the needles into the tissue is a more reliable actuation measure than twisting the coil into the tissue. Also, because the forces applied to the tissue by the engaging point of the device is not accompanied by an opposite reacting force of another engaging point of the device, all reaction forces must be provided through the shaft of the device.

A common general flexible endoscopic tissue grasper is most widely used today for manipulating gastrointestinal tissue (for example, one that is made by the Olympus company under the name Olympus Grasping Forceps (Catalog Number FG-49L-1)). A drawback to the Olympus grasper is its inability to reliably grasp muscularis through the mucosal layer. Another drawback is the requirement to maintain pressure on the handle while grasping the tissue. This ties up the user's hands and could lead to inadvertent release of the tissue.

The prior art devices are not constructed to easily, securely, selectively, and precisely engage the tissue during the surgical procedure.

SUMMARY OF THE INVENTION

Various endoscopic procedures require manipulation of specific layers in the gastric wall. For instance, in the case of mucosal resection, the mucosa is tented away from the muscularis and resected away. Such a procedure is currently performed by injecting fluid beneath the mucosa to, thus, lift the mucosa from the muscularis. The mucosal tissue is, then, resected using electrocautery. The tissue retractor of the present invention can be used to selectively grasp the mucosa and lift it from the muscularis, thus enabling and simplifying mucosal resection. In the case of forming a full thickness plication in the stomach, the stronger muscular layer of the gastric wall must be grasped to ensure that the full thickness of the wall will be retracted when forming the plication. By tailoring the needles and the way in which they exit from the tip of the retractor, the retractor can be made to selectively grasp the different layers in the gastric wall. Being able to grasp a specific layer of the gastrointestinal wall is advantageous depending on the requirements of the specific procedure being performed.

As it is well known, the tissue in the alimentary tract has three main layers that are, from the innermost layer to outermost layer, the mucosa, the muscularis, and the serosa. The mucosa is a relatively thin layer, loosely attached to the muscularis, and, in some procedures, retraction of only the mucosa is not desirable. For example, if the mucosa is retracted in a procedure for treatment of GERD, such retraction will not provide a sufficient plication for insertion of a GERD-treating fastener. In this exemplary procedure, retraction of entire thickness of the stomach wall is desired, as such retraction will provide a beneficial plication for insertion of the GERD fastener.

The present invention provides a rotating tissue retractor and method for using the retractor that overcome the hereinafore-mentioned disadvantages of the heretofore-known devices and methods of this general type and that can effectively grab the tissue of the alimentary tract during operation and avoid reaching into the serosa, can grab the tissue without compressing and/or tearing the tissue, and can rotate the end effector independently of the outer device shaft.

The tissue retractor of the present invention has applications in laparoscopic and general surgery as well. It can be used to retract organs that are in the way of the surgical field, or to appose and hold tissue in place during suturing. An advantage to an organ retractor or tissue apposition device according to the present invention is the ability to retain the tissue without having to clamp onto it. The tissue retractor atraumatically retains the tissue by penetrating it with fine needles and independent rotation of the end effector allows the needles to extend into the tissue in a most-desirable orientation. To further reduce the trauma to the tissue, the needles can be formed with a conical point instead of a faceted point. This is especially advantageous when retracting sensitive organs such as the pancreas. Currently available tissue graspers use more aggressive serrated articulating end effectors, which require clamping forces to retain the tissue and, therefore, potentially cause trauma in the process. The needles can also be formed with a kink in the distal end. If the kink extends towards the interior center of the curved path, then such an orientation will allow the needle to tunnel within the tissue better in the desired curved (e.g., circular) direction.

A common procedure during flexible endoscopy is the exchange of an endoscope during a procedure. If the first scope is in a position within the alimentary tract that was difficult to achieve, and it is desired that the second (exchange) scope be in the same position, the tissue retractor could be used to guide the second scope into the position of the first scope. A flexible endoscopic version of the retractor according to the present invention can be provided with a removable handle. Therefore, when a scope exchange is necessary, the tissue retractor can be passed through the first scope and deployed in the tissue at the desired location. The handle of the tissue retractor can, then, be removed. The first scope can, then, be slid over the tissue retractor shaft, leaving the retractor shaft in-place, and removed. Then, the second scope can be fed over the tissue retractor shaft, much like a guidewire, and the scope advanced to the original position. Thereafter, the shaft can be released and removed when desired.

Also, a version of the retractor can be made that allows the distal tip of the retractor to be deployed in the tissue and, then, decoupled from the main shaft. In such an embodiment, the distal tip of the device is coupled removably to the shaft and the actuation wire is coupled removably to the needles. The needles are deployed on the target tissue and the shaft of the device is pulled proximally, thus allowing the actuation wire to slip free of the needles and the tip to slide free of the shaft. The released tip being firmly attached to the tissue has application as a marker, suture attachment points for a purse string closure, a tissue apposition suture, and an anchoring point for various things such as pH probes, miniature capsule cameras, and feeding tubes.

The device and method of the present invention allows the needles to be configured such that they can be made to penetrate deep through the mucosa and into the muscularis, making a more secure attachment to the tissue, while substantially reducing the possibility of puncturing the serosa, or penetrate less deep to grasp only the mucosal layer. The present invention engages the tissue at two opposing points, so that the tissue-engaging forces of each point react against the forces of the other; the result is that there is very little reaction load transmitted to the flexible shaft of the device. This deployment of the device does not require substantial torque or thrust loads to be supplied by the shaft. The present invention provides better visibility during placement of the retractor as no jaws are used that could obscure a view of the retraction site. It is also less traumatic to the tissue than a conventional articulating grasper due to the fine diameter and non-cutting points of the needles. The handle can be released from the user's grasp after the needles have been deployed, while still maintaining a secure attachment to the tissue, which frees the user to do other tasks. The tissue retractor is separate from an endoscope but sized to fit within a working channel of the endoscope. In exemplary embodiments, the tissue retractor of the present invention has an outer diameter of 1.8 mm and 2.4 mm.

Although the invention is illustrated and described herein as embodied in a flexible, selectively rotatable tissue retractor and method for using the retractor, it is, nevertheless, not intended to be limited to the details shown because various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.

As used herein, the term “about” or “approximately” applies to all numeric values, whether or not explicitly indicated. These terms generally refer to a range of numbers that one of skill in the art would consider equivalent to the recited values (i.e., having the same function or result). In many instances these terms may include numbers that are rounded to the nearest significant figure.

In this document, the term “longitudinal” should be understood to mean in a direction corresponding to an elongated direction of the device's shaft—between the handle and the end effector and the term “distal” should be understood to mean in a direction towards the end effector and “proximal” should be understood to mean in a direction towards the handle.

DETAILED DESCRIPTION

Referring now to the figures of the drawings in detail and first, particularly toFIG. 1thereof, there is shown a cutaway elevational view of a flexible tissue retractor100with a pair of needles102a,102bin an extended position, according to an embodiment of the invention. The components of the retractor100further include, among other elements, a connector126, a distal needle body106, a distal stop122, and a rotation joint115.

In the preferred configuration, the needles102a,102bare made of a flexible shape memory material having a memory shape, in particular, one displaying temperature- and stress-induced martensite. The preferred material is Nitinol, a superelastic Nickel Titanium alloy having the shape memory features as described, for example, in U.S. Pat. Nos. 4,665,906, 5,067,957, and 5,597,378 to Jervis. The needles102a,102bare formed to have the memory shape shown inFIGS. 1 to 6at least at room and body temperature, in particular, above approximately 10° C.

The connector126shown is a sleeve that can be squeezed by a mechanical stress to be fixedly connected to a needle body106of one of the needles,102bin this example. Alternatively, the connector126can be a heat-contacted sleeve in which heat welds, forms, molds, or otherwise shapes the body of the connector126to affix the connector126to the body of the needle102b. The straight body section of the other needle102acan be coupled to the first needle102bby any available method, such as welding.

FIGS. 2-4show enlarged cutaway views of the head104of the retractor100. Referring first toFIG. 2, a first108of two head halves108,110(110not shown in this view) is surrounded and secured by the distal coil winding114, which, in turn, is surrounded by an outer jacket116. The first head half108has a channel202that receives and guides a first102aof the two needles102a,102bout of the retractor100when the needles102a,102bare deployed, as is the case inFIGS. 1-4. In one embodiment of the present invention, the first head half108also has an end204that partly surrounds the needle102aand, when combined with the second head half110, creates channels that provide guidance to the needles102a,102band ensures that the needles102a,102beach travel along individual paths without interfering with each other.

InFIG. 3, a shim300is placed over the first head half108and the first needle102a. The shim300serves three functions. A first function is covering the top of the channel202and preventing the first needle102afrom leaving the channel202. A second function is to separate the needles102a,102bfrom each other. Thirdly, the shim300, as can be seen inFIGS. 3 and 4, has an end302that extends longitudinally out of the retractor head104. The shim end302has a shape and, as will be shown below, can be any of a variety of shapes that serve various functions and provide a variety of advantages.

FIG. 4shows the second needle102bplaced within the flexible tissue retractor and separated from the first needle102aby the shim300. As set forth above, the shape memory of the needles102a,102bimparts a force to whatever structure is preventing the needles102a,102bfrom being in the defined memory shape. This force also imparts a torque upon the needles102a,102bwhen the needles102a,102bare at least partially deformed by being retracted into the channel202in the head halves108,110. The imparted torque, if left unchecked, would move the needles102a,102bout of the channel202. Without the shim300, therefore, the two needles102a,102bwould twist around one another and possibly jump into the other needle's respective groove. To prevent such movement, and to insure that each of the needles102a,102bstay within its respective channel202, the shim300is disposed between the two needles102a,102b. In such a position, a flat version of the shim300forms an interior first bearing surface for each of the needles102a,102band the channel202forms an almost circular exterior second bearing surface for each of the needles102a,102b. Alternatively, the shim300can have a non-illustrated depressed hemispherically cross-sectioned groove corresponding to the channel202on each of the head halves108,110. Thus, the channel202need not so deeply penetrate the head halves108,110.

The shim300has other significant features. First, as shown inFIG. 3, the distal-most end302of the shim300can have an anchoring shape. The function of the anchoring shape is to keep the end302in place and prevent the end302from glancing off a tissue surface (i.e., human tissue, in particular, the wall of the stomach) when the tip302of the tissue retractor100is pushed initially against the tissue surface. It is noted that the tissue surface is compressed therein and around the shaped end302to secure the retractor100at a grasping location on the surface and prevent radial movement with respect to the shaped end302. In one embodiment, the end302of the shim300is provided with a soft material, such as cotton, which absorbs liquid as well as provides a soft contact area to be placed against tissue. The soft material resists movement of the device100with reference to the tissue that it is in contact with, as well as avoids any tissue damage.

In a mechanically efficient manner, the shim300can be provided with non-illustrated thread points304having a pitch equal to, or slightly different than, a pitch of an interior non-illustrated female thread306of the distal coil winding114. Accordingly, when the tip is entirely assembled with the shim300and needles102a,102b, the thread points304can be used as a male thread to secure the tip in the distal end of the distal coil winding114.

FIG. 5shows a partially cutaway perspective view of the retractor100with both head halves108,110at the head104and securing the two needles102a,102b. The view ofFIG. 5clearly shows the two separate paths that the head halves108,110provide to the needles102a,102b.FIG. 6provides another perspective view of the head104of the retractor100with the head halves108,110accommodating and securing the needles102a,102bin channels602,604, respectively. Thus, when the needles102a,102bare moved proximally, the bodies of the needles102a,102b, respectively, are guided through the channels602,604, respectively, and straightened when exiting the channels602,604in a proximal direction, indicated by arrow608. With further proximal movement, the needle tips610,612are, ultimately, fully retracted into the channels602,604.

Referring again briefly toFIG. 1, a distal stop122is shown within the distal section118and downstream from the proximal section120. Generally speaking, the distal stop122prevents the needle tips610,612(shown inFIG. 6) from completely exiting the proximal end of the head halves108,110and, thereby, rendering the flexible tissue retractor100inoperable. The reason why the retractor100would be rendered inoperable is because of the unique nature of the needles102a,102b. Thus, if the needle tips610,612are retracted past a proximal end surface614of the head halves108,110, the needle tips610,612would spring towards their memory shape and completely out of the grooves602,604to rest inside the distal coil winding114. In such a position, the bias provided by the shape memory would substantially prevent the retractor100from being operated, at least until the retractor100was disassembled, fixed, and, thereafter, reassembled. As will be explained in more detail below, the stop122is laterally fixed to the winding coil114. As the body106of the needle102bmoves proximally in a lateral direction124through the stop122, the distance between the connector126and the stop122will reduce until the two make contact. At that point, the needles cannot move any further in the proximal direction.

Still referring toFIG. 1, it can be seen that a rotation joint115rotatably couples the distal section118to a proximal section120. Through the rotation joint115, a manipulation at the proximal end of the proximal section120advantageously controllably rotates the needles102a,102bto, for instance, perform surgical functions during a medical procedure. Details of the rotation joint115will now be described in conjunction withFIG. 7.

FIG. 7shows a cutaway partial view of the retractor100and, in particular, the rotation joint115. The rotation joint115includes a swivel bushing702that is nested within a swivel coil coupler704and swivel bushing stop706. Surrounding the swivel bushing702is the distal coil winding114, which is itself surrounded by a distal outer jacket712. The distal coil winding114securely fixedly holds the swivel bushing702so that a rotation of the swivel bushing702results in a corresponding 1:1 rotation of the distal coil winding114. Similarly, a proximal coil710securely fixedly holds the swivel coil coupler704so that a rotation of the swivel coil coupler704results in a corresponding 1:1 rotation of the proximal coil710. A proximal outer jacket708surrounds and protects the proximal coil710.

The body of the needle106passes from the proximal section120to the distal section118through the rotation joint115and it is this needle body106that causes the rotation of the distal section118relative to the proximal section120during a surgical procedure. According to one embodiment of the present invention, the wire passes through slot716in the swivel bushing702. The slot716provides at least one engaging surface718for the needle body106to align with. In this example, the slot716is not round, but is instead a groove or resembles an ovular shape with flat opposing side walls718. This slot can better be seen inFIG. 9. The needle body106is also provided with at least one engaging surface714, which, in this example, is a flat edge that, once inserted into the slot716, prevents rotation of the needle body106independent of the swivel bushing702. As previously stated, the swivel bushing702rotates independent of the swivel coil coupler704. As a result, when the distal outer jacket712, which is fixedly coupled to the swivel coil coupler704by the proximal coil710, is rotationally fixed, and the needle body106is rotated with respect to the outer jacket712, the keyed coupling between the flattened section of the needle body106and the slot716in the swivel bushing702causes the swivel bushing702and affixed distal coil winding114and proximal outer jacket708to rotate as well. This keyed relationship between the needle body106and the swivel bushing702can also be seen inFIGS. 35-36.

FIG. 7also shows that, on the proximal side of the rotation joint115, the needle body106is wrapped in a sheath718, preferably, of polyethylene or TEFLON®. Because there is a difference between the outer diameter of the needle body106and the inner diameter of the coil winding114, when pushed against a load, the needle body106may flex and bend. The sheath718fills the space between the outer diameter of the needle body106and the inner diameter of the coil winding114and prevents the needle body from flexing or buckling. In addition, the sheath718also insolates the needle body106from the proximal coil710and allows the needle body106to rotate within the proximal section120with limited resistance.

Continuing further along the flexible tissue retractor100, the needle body106passes through the proximal stop section122, as shown inFIG. 8. The proximal stop section122includes a bushing802, a proximal stop804, and a strain relief coil806, which are all fixedly secured to the proximal coil710. In addition, an actuation wire inner sheath808surrounds the proximal needle body106. The proximal stop section122provides a lateral motion limit to the needle body106and is positioned so that the needles102a,102bcan be fully retracted into the head104, but cannot be retracted beyond the proximal extent of the needle channels602,604. Specifically, as is shown inFIG. 28, when the needle body106is pulled away from the head104of the flexible tissue retractor100, the distal stop122will make contact with the bushing802, supported by the proximal stop804. The contact between the laterally sliding distal stop122and the fixed bushing802resting against the proximal stop804prevents any further sliding of the distal needle body106in the proximal direction.

Looking back toFIG. 8, the stop804is hollow to accommodate the needle body106slidably therein (in a preferred embodiment, the sheath808is not allowed to pass through the stop804). Thus, the internal diameter of the stop804is at least slightly greater than the external diameter of the needle body106. In one embodiment, the stop804is provided with a male thread on its external surface. A groove is provided at the distal end of the stop804, the groove, preferably, being shaped to accommodate the working end of a flat-head screwdriver for insertion within the male threads of the stop804.

The strain relief coil806prevents severe bending of the proximal coil710to an extent where the needle body106would get bent or be unable to slide laterally through the stop122.

Referring now toFIG. 10, the distal coil winding114is made in the fashion of a tight spring, to provide it with longitudinal strength while having slight longitudinal expandability/give and to provide it simultaneously with radial flexibility or whip. Due to such coiling, the interior of the distal coil winding114has a natural female thread which securely holds the head halves108,110. In addition, spot welds1002a-nare provided on opposing sides of the distal coil winding114. The spot welds1002a-nserve as winding coupling points and provide longitudinal rigidity to the coil winding114and prevents the individual windings from separating laterally. This is advantageous, since the outer jacket116terminates at this distal end and support from the jacket is minimized at this point. The welds also provide torsional rigidity in a first direction1004, while allowing flexibility in a second direction1006. Specifically, the welds1002a-nprevent expansion or separation of the coils in the direction1012and1004, but act as pivots in the direction1006and allow the coils to slightly separate. This restriction in flexibility is also advantageous during surgical procedures as it allows the operator to rotate the distal end of the device100to position the welds1002a-nin a particular orientation to navigate particular channels where prevention of bending is preferred.

The tip1008can be made from a thin walled deep drawn part with a rounded end to maximize the internal diameter of the tip1008, thus allowing for arcuate needles of greater chord height (shorter, smaller radius) to fit within. The exit windows1010for the needles102a,102bcan be pierced through the wall as part of the deep drawing operation or machined through using various methods including at least one of: wire EDM, laser, conventional milling, etc.

As can be seen fromFIG. 11, the needles102aand102bpass through openings1102,1104on the distal tip1008to extend out of the distal tip1008. To explain the movement of the needles102a,102bthrough the tip1008,FIGS. 13 to 20show different views of the needles102a,102b, which can move between a retracted position (FIGS. 13 and 17) and a fully extended position (FIGS. 16 and 20). The entirety of such movement is referred to as selective movement because actuation of the needles is selected by a user anywhere between (FIGS. 14,15,18, and19) the fully retracted and fully extended positions.

FIGS. 13-16show a needle tip1300with a bend that is different from the bend angle of the needle tip1700, shown inFIGS. 17-20. More specifically, needle tip1700is bent at a greater natural angle of curvature than is needle tip1300. The effect of each of these exemplary needle tips is shown inFIG. 21and explained below.

In a preferred embodiment, the flexible tissue retractor100is an endoscopic device that is passed through the working channel of a flexible endoscope. In such a procedure, as shown inFIG. 21, the retractor100is used to hold esophageal or any other gastrointestinal tissue2102so that it can be moved or manipulated in some way. As the retractor100is passed through one of the working channels of an endoscope, the needles102a,102bare in a fully retracted position in the tip1008, as shown inFIGS. 13 and 17. Once the tip1008is set into place, it is pushed against the tissue2102. Preferably, the shim300(not shown inFIG. 21) has the anchoring shaped end302(seeFIGS. 3,4,11, and12) to help pinpoint a desired location on the tissue and place the tip1008at the desired location. The needles102a,102bare then actuated to extend out of the tip1008and pierce the tissue2102. As the needles102a,102bextend into and curl around the tissue2102, it is retained securely by the shaped end302. Now, the tissue2102can be manipulated as required. To release the tissue2102, the needles102a,102bneed merely be retracted back into the tip1008. Because the needles102a,102b, made of a shape memory alloy such as nitinol, are pre-formed into the arcuate memory shape, they retain the memory shape through repeated retractions/deployments.

The needle paths2104and2106shown inFIG. 21illustrate the difference between a needle tip1700with a distal end bend and a needle tip1300without the bend or with a shallower bend on the same device (for illustration) to show that the needle tip1700with the bend creates a shallower (D1) tunneling path.

FIG. 22shows a handle2200of the flexible tissue retractor100, which is the actuation device that controls the extension and retraction of the needles102a,102b. The handle2200includes a nose assembly2202, a handle assembly2204, a push-rod assembly2206, and a locking assembly2208.

Referring now toFIG. 23, it can be seen that handle assembly2204includes a handle body2300(not shown inFIG. 22) surrounding the retraction spring2210. The push-rod assembly2206is composed of a push-rod2302and a knob2304.

The needle body106is secured and rotationally fixed to a piston2320that is itself rotationally fixed to the push-rod2302, which is rotationally fixed to the knob2304. The plunder is rotatable within the handle body2300. An operator, therefore, by secure the handle body2300with one hand, is able to cause rotation of the needles102a,102bby simply rotating the knob2304, which in turn rotates: the push-rod2302, the piston2320, needle body106, swivel bushing702, and the entire remaining distal end118of the device100.

A button2306for locking the push rod2302is installed in a button hollow2308, which is formed near the proximal end of the handle body2300. The button2306is disposed upon a button spring2310, which is also received in the button hollow2308. The button2306has a transverse bore2314for receiving a catch pin2312therein. In an installed position, a contained space2316, defined by the catch pin2312and the interior surface of the bore2314in the button2306enclose the push rod2302to, thereby, retain the button2306in the handle body2300.

The push-rod2302is also formed with a circumferential catch pin groove2318used to capture the catch pin2312when the push-rod2302is pressed from a proximal position shown inFIG. 23to a distal position shown inFIG. 26. In the proximal position, the needles102a,102bare retracted within the tip1008(FIG. 27) and, in the distal position, the needles102a,102bare extended out of the tip1008(FIG. 30). When the catch pin2312is within the groove2318, the needles102a,102bare in the extended position and the knob440can only be moved slightly; such movement is permitted by the play created by the length of the groove2318along the longitudinal extent of the push-rod2302. Because the needles102a,102bare held in the deployed position, the user is, then, free to let go of the handle without the fear of needle102a,102bretraction, and to use their hands for other surgical procedures until retraction of the needles102a,102bis desired. A user can selectively engage the button2306to capture the push-rod2302with the catch pin2312or allow the push-rod2302to move freely in the longitudinal direction by pressing the button2306to move the catch pin2312out of the way so that the groove2318does not engage the catch pin2312. By pressing the button2306down, the catch-pin2312is forced out of the catch-pin groove2318, thereby unlocking the push-rod2302and automatically retracting the needles102a,102bbecause the retraction spring2210imparts a proximally directed bias to the piston2320. Accordingly, the locking function of the button2306can be said to selectively retain the needles102a,102bin a given position.

The push-rod2302is also provide with a plurality of additional intermediate circumferential catch pin grooves2402,2404,2406, which are, in this embodiment, three in number. The intermediate catch pin grooves2402,2404,2406advantageously allow the distal section118of the retractor100to rotate independent of the proximal section120and unencumbered by frictional forces when the needles102a,102bare retracted within the tip1008. This feature is best explained by looking briefly toFIGS. 27-29.FIG. 27shows that the needles102a,102bare in a retracted position. When in this position, as shown inFIG. 28, the distal stop122is pressed against the bushing802of the proximal stop804by the spring2210. This contact between the distal stop122and the bushing802is a frictional force that resists rotation. In one embodiment, this force applied by the spring2210is approximately 6 lbs.

Of course, when the needles102a,102bare fully deployed, as shown inFIGS. 30-32, there is no friction between the distal stop122and the bushing802because they are not in contact with each other. Through utilization of the intermediate catch pin grooves2402,2404,2406, removal or at least reduction of this frictional contact can be achieved without fully deploying the needles102a,102b.

Referring back toFIGS. 24 and 25, by pressing the knob2304distally, the catch pin2312catches in one of the plurality of intermediate pin grooves2402,2404,2406and “ratchets” to a position that sufficiently counters the frictional spring-imposed pressure from between the distal stop122and the bushing802.

FIG. 36shows the rotation joint115with a friction reducing washer3600inserted between the swivel bushing702and the swivel coil coupler704.

FIG. 38shows a cross-sectional perspective view of a distal tip3800that provides rotation of the needles102a,102b, according to an embodiment of the present invention. The distal tip3800includes the two head halves108,110separated by the shim300. In this embodiment, the head halves108and110are held in place by a distal ring3802that rests against a step3803formed in the head halves108and110. The distal ring may or may not be affixed to the head halves108,110, but is made of a low-friction material, such as TEFLON, for instance. A sleeve3800is then slid over the head halves108and110and abuts the ring3802. A second ring3806is then slid over a proximal portion of the head halves108and110and abuts a second step3807formed in the head halves108and110. Then second ring3806is fixedly attached to the head halves108and110by, for instance, press fitting, welding, soldering, gluing, etc. in a way that prevents or resists the removal of the second ring3806from the head halves108and110. The second ring3806, thereby retains the sleeve3804and first ring3802.

The proximal inner surface3810of the sleeve3804is then fixedly attached to the windings of the coil114. The result is that the coil114and the sleeve3804remain fixed to each other while the second ring3806, the head halves108,110, the needles102a,102b, and the shim300rotate with respect to the sleeve3804and coil114. The first ring3802reduces friction between the head halves108and110and sleeve3804. In this embodiment, the rotation joint115ofFIG. 1is not needed.

There have been described and illustrated herein several embodiments of retractors and methods for the endoluminal treatment of Gastroesophageal Reflux Disease (GERD). While particular embodiments of the invention have been described, it is not intended that the invention be limited thereto, as it is intended that the invention be as broad in scope as the art will allow and that the specification be read likewise. For example, while particular preferred dimensions have been provided for the retractor, it is appreciated that the system and its elements may have different relative sizes. For example, the cross-sectional areas can be decreased further if a pediatric endoscope (4 to 6 mm) is used. Also, while a “looking back” clip implantation instrument has been disclosed particularly for fastener application designed to treat GERD, it is appreciated that a “forward looking” straight instrument with similar jaw assembly can be used to apply the fastener for treatments of other conditions, e.g., obesity, ulceration, stomach cancer, implantation of pH measurement or monitoring devices, feeding tubes, etc. Moreover, a straight device can be smaller in diameter and be operated through a working channel of an endoscope. It will, therefore, be appreciated by those skilled in the art that yet other modifications could be made to the provided invention without deviating from its spirit and scope as so claimed.