Clip devices and methods of delivery and deployment

The present embodiments provide systems and methods for deploying at least one clip device. In a first embodiment, the system comprises a first clip device having first and second arms. The first clip device and an associated sliding ring are configured to be selectively advanced through a lumen of an inner catheter. Selective positioning of an outer catheter over a distal region of the inner catheter causes a distal region of the inner catheter to bow radially inward to form a constriction that securely engages the sliding ring of the first clip device, thereby allowing for partial closure and repositioning of the first clip device. In an alternative embodiment, a delivery system includes a single catheter having a tapered distal region, such that upon ejection of the sliding ring from the distal end of the catheter, the sliding ring is dimensioned to abut the distal end of the catheter. In any of the embodiments, multiple clips may be sequentially loaded and deployed using the delivery systems. Various clip designs and a loading cylinder are also disclosed.

BACKGROUND

Conventionally, a clip may be introduced into a body cavity through an endoscope to grasp living tissue of a body cavity for hemostasis, marking, and/or ligating. In addition, clips are now being used in a number of applications related to gastrointestinal bleeding such as peptic ulcers, Mallory-Weiss tears, Dieulafoy's lesions, angiomas, post-papillotomy bleeding, and small varices with active bleeding.

Gastrointestinal bleeding is a somewhat common and serious condition that is often fatal if left untreated. This problem has prompted the development of a number of endoscopic therapeutic approaches to achieve hemostasis such as the injection of sclerosing agents and contact thermo-coagulation techniques. Although such approaches are often effective, bleeding continues for many patients and corrective surgery therefore becomes necessary. Because surgery is an invasive technique that is associated with a high morbidity rate and many other undesirable side effects, there exists a need for highly effective, less invasive procedures.

Mechanical hemostatic devices have been used in various parts of the body, including gastrointestinal applications. Such devices are typically in the form of clamps, clips, staples and sutures, which are able to apply sufficient constrictive forces to blood vessels so as to limit or interrupt blood flow. One of the problems associated with conventional hemostatic devices, however, is that many devices are not strong enough to cause permanent hemostasis. Further, typically once such mechanical hemostatic devices are at least partially deployed, they cannot be opened and closed repeatedly before the final release of the device, which may result in possible permanent deployment of the device at an undesirable location.

Still further, mechanical hemostatic devices typically are loaded, one at a time, within an introducer equipped to deliver and deploy the device. A first hemostatic device may be deployed, but if it becomes desirable to deliver and deploy a second hemostatic device, the introducer typically must be removed from the patient's body in order to load the second hemostatic device. The introducer then is loaded back into the patient's body to deploy the second hemostatic device, and the process is repeated for each subsequent device. However, the process of deploying only one hemostatic device at a time may become very time consuming and inconvenient, causing significant delays when it may be imperative to quickly stop bleeding.

SUMMARY

The present embodiments provide systems and methods for deploying at least one clip device. In each embodiment, multiple clips may be sequentially loaded and deployed using the delivery systems. Various clip designs and a loading cylinder are also disclosed.

In a first embodiment, the system comprises a first clip device having first and second arms. The first clip device and an associated sliding ring are configured to be selectively advanced through a lumen of an inner catheter. Selective positioning of an outer catheter over a distal region of the inner catheter causes a distal region of the inner catheter to bow radially inward to form a constriction that securely engages the sliding ring of the first clip device. When the sliding ring is securely engaged, the first and second arms of the first clip device are movable longitudinally relative to the sliding ring, thereby allowing for partial closure and repositioning of the first clip device.

Advantageously, in this manner, any number of clip devices may be sequentially loaded into the lumen of the catheter and deployed, one at a time, without the need to remove the inner and outer catheters from the patient's body and individually re-load clip devices, thereby reducing operating time. Further, each of the clip devices advantageously may move between the open and closed states any number of times before final deployment.

In an alternative embodiment, a delivery system includes a catheter having proximal and distal ends, a lumen extending therebetween, and a tapered distal region. The catheter comprises a first inner diameter at a location proximal to the tapered distal region, and further has a second inner diameter at the distal end, wherein the second inner diameter is less than the first inner diameter. The sliding ring comprises an outer diameter that is less than the first inner diameter of the catheter and greater than the second inner diameter of the catheter. The tapered distal region of the catheter is flexible such that application of a predetermined distally-oriented forced imposed upon the sliding ring ejects the sliding ring from the distal end of the catheter. Upon ejection of the sliding ring from the distal end of the catheter, the sliding ring is dimensioned to abut the distal end of the catheter. At this time, proximal retraction of the first and second arms of the first clip device relative to the sliding ring moves the clip device between the open and closed states.

Other systems, methods, features and advantages of the invention will be, or will become, apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be within the scope of the invention, and be encompassed by the following claims.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the present application, the term “proximal” refers to a direction that is generally towards a physician during a medical procedure, while the term “distal” refers to a direction that is generally towards a target site within a patient's anatomy during a medical procedure.

Referring now toFIGS. 1-6, a first embodiment of a clip device is shown, along with an exemplary system for delivery and deployment of at least one of the clip devices. In this embodiment, first and second clip devices20aand20bare provided. The first clip device20acomprises a first arm30aand a second arm40a. The first arm30ahas a proximal end32aand a distal end34a, while the second arm40ahas a proximal end42aand a distal end44a. The proximal end32aof the first arm30aand the proximal end42aof the second arm40aare joined together by a proximal securement member60a, which may comprise an adhesive, solder, weld, mechanical attachment device, or any other suitable mechanism, that joins the proximal ends32aand42aof the arms30aand40atogether.

The clip device20afurther comprises a sliding ring50a, which has an inner diameter that is slightly larger than an outer diameter of the first and second arms30aand40acombined. The proximal securement member60alimits proximal movement of the sliding ring50a. In use, the sliding ring50ais dimensioned to slide over the first and second arms30aand40a, causing the arms to move to a closed position, as explained further inFIG. 4below.

The distal ends34aand44aof the arms30aand40aare preferably bent in radially inward directions to form tips38aand48a, respectively, as best seen inFIG. 2. The tips38aand48aare configured to grasp and/or pierce tissue. While two arms30aand40aare depicted in the embodiment ofFIGS. 1-5, it is contemplated that a greater number of arms may be used. For example, as explained inFIGS. 13-14below, alternative clip devices120a′ and120a″ comprise three and four arms, respectively.

The first clip device20ahas a delivery state, an open state, and a closed state. In the delivery state, the first clip device20ais disposed within a lumen78of an inner catheter70. The lumen78of the inner catheter70is dimensioned such that the distal ends34aand44aof the arms30aand40aare held adjacent to one another in the delivery state, as depicted inFIG. 1.

In the open state, the distal ends34aand44aof the first and second arms30aand40a, respectively, tend to be spaced apart from one another, as shown inFIGS. 2-3. The first and second arms30aand40aare biased to assume the open state when the distal ends34aand44aare no longer constrained by the inner catheter70. The distal ends34aand44amay be biased to assume the open state either due to the inherent resilient properties of the material forming the first and second arms30aand40a, or alternatively, the first and second arms30aand40amay be heat-set to assume the deployed configuration shown. The first and second arms30aand40amay be made from any suitable resilient material such as stainless steel, nitinol, plastic, and the like. Optionally, the arms of the clip may be formed of a resorbable material such as the magnesium alloy WE43, which can dissolve over time instead of needing to pass through a patient's gastrointestinal system. Further, the first and second arms30aand40amay have a cross-sectional shape that is round, square, rectangular, triangular, pie-shaped, truncated cone, and the like.

In the closed state, the sliding ring50ais translated distally relative to the first and second arms30aand40a, as depicted inFIGS. 4-5and explained further below. At this time, the distal ends34aand44aof the first and second arms30aand40a, respectively, are closed together and the tips38aand48aare configured to grasp tissue and facilitate tissue closure and hemostasis. The sliding ring50amay lockingly engage the distal ends34aand44aof the first and second arms30aand40a, respectively, and may be sized so that it will not slide distally over the ends of the first and second arms30aand40ain the closed state. Optionally, one or more distal stop members, such as a solder or a mechanical member, may be disposed on the first arm30aand/or the second arm40ato limit distal advancement of the sliding ring50a.

Referring still toFIGS. 1-5, an exemplary system is described for delivery and deployment of at least one of the clip devices. The delivery system comprises the inner catheter70having the lumen78, as noted above, and further comprises an outer catheter80having a lumen88. In the embodiment ofFIGS. 1-5, first and second clip devices20aand20bare provided for sequential deployment, and the second clip device20bis generally identical to the first clip device20a.

The inner catheter70comprises an outer diameter that is less than an inner diameter of the outer catheter80, thereby allowing the inner catheter70to be longitudinally advanced within the lumen88of the outer catheter80. The inner catheter70further comprises an inner diameter that allows the first and second clip devices20aand20bto be loaded within the lumen78of the inner catheter70, as shown inFIG. 1.

The inner catheter70comprises a distal end74and a flexible distal region75. The flexible distal region75may be selectively moved in a radially inward direction, for purposes described further below. Preferably, a plurality of slits77are formed in the distal end74, as shown inFIG. 6, to permit the radial flexibility along the distal region75.

At least one wedge member92may be positioned along the flexible distal region75of the inner catheter70. In the embodiment shown, a plurality of wedge members92having a tapered shape are disposed between the inner catheter70and the outer catheter80, causing the flexible distal region75of the inner catheter70to move radially inward to form a constriction79when the outer catheter80is advanced against the wedge member92, as shown inFIGS. 3-4. The wedge member92may comprise a biocompatible glue, plastic, metal or other suitable material, and may comprise other shapes besides the tapered shape depicted to accomplish the objectives described below. Alternatively, one or more wedge members92may be formed as an integral portion of the inner catheter70along the distal region75.

The outer catheter80may comprise a rigid or substantially rigid material, such as stainless steel or plastic materials, which substantially prohibits radial outward movement of the wedge member92and the flexible distal region75of the inner catheter70when a distal end84of the outer catheter80covers these regions, as shown inFIGS. 3-4. However, when the distal end84of the outer catheter80is retracted proximally beyond the wedge member92and the flexible distal region75of the inner catheter70, the flexible distal region75may move radially outward and the constriction79may be removed, as depicted inFIG. 5below.

In one exemplary method, the first and second clip devices20aand20bare loaded sequentially such that the first clip device20ais loaded distal to the second clip device20bwithin the lumen78of the inner catheter70, as shown inFIG. 1. A stylet90may be positioned in the lumen78at a location proximal to the second clip device20b.

In one embodiment, the first and second clip devices20aand20beach comprise proximal retainers64aand64b, respectively. The proximal retainers64aand64bmay be in the form of loop members having outer diameters that are smaller than the inner diameter of the inner catheter70. In use, the first and second clip devices20aand20bmay be loaded within the inner catheter70such that the distal ends34band44bof the second clip device20bsecurely engage the proximal retainer64aof the first clip device20awhen the inner catheter70is positioned over the connection as shown inFIGS. 1-4. When the inner catheter70is no longer positioned over this connection, as shown inFIG. 5, the first and second clip devices20aand20bmay disengage from one another, as explained below.

The stylet90may comprise a retainer92, such as a hook member, that engages the proximal retainer64bat the proximal end of the second clip device20bwhen the inner catheter70is positioned over this connection, as shown inFIGS. 1-5. Accordingly, proximal and distal advancement of the stylet90causes a corresponding movement of the first and second clip devices20aand20b.

It should be noted that while two clip devices are shown in this example, any number may be used and sequentially loaded into the inner catheter70in an abutting manner distal to the stylet90. Moreover, while one exemplary retainer arrangement is shown in the form of a hook and loop connection, various other retainer arrangements are possible. By way of example, alternative retainer arrangements to couple the stylet90to the second clip device20b, and/or to couple the first and second clip devices20aand20btogether, are described in U.S. Pat. Pub. No. 2007/0282355, the disclosure of which is hereby incorporated by reference in its entirety.

The stylet90, the first clip device20aand the second clip device20bare loaded into the inner catheter70as shown inFIG. 1. Optionally, at this time, the outer catheter80may be positioned over the inner catheter70, as shown inFIG. 3, such that the constriction79is formed via the wedge member92. The constriction79may prevent the first and second arms30aand40aof the first clip device from extending distal to the inner catheter70to reduce the likelihood of inadvertent piercing during delivery.

Referring toFIG. 2, the outer catheter80is positioned proximally relative to the inner catheter70, thereby exposing the distal region75of the inner catheter70. The stylet90is advanced distally, relative to the inner catheter70and the outer catheter80, to cause distal advancement of the second clip device20band corresponding distal advancement of the first clip device20ain an abutting manner. The stylet90is advanced distally until the sliding ring50aof the first clip device20ais aligned with the distal region75of the inner catheter70, as shown inFIG. 2. At this time, the distal ends34aand44aof the first and second arms30aand40a, respectively, of the first clip device20aare advanced distally beyond the distal end74of the catheter70, and when unconstrained, tend to bow in a radially outward direction spaced apart from one another, as depicted inFIG. 2.

Referring toFIG. 3, in a next step, the outer catheter80is advanced distally relative to the inner catheter70, thereby engaging the wedge members92and urging the distal end74of the inner catheter70into engagement with the sliding ring50a. A friction fit is achieved such that the sliding ring50ais held steady. At this time, the stylet90may be proximally and distally advanced, thus causing corresponding movement of the first and second arms30aand40arelative to the sliding ring50a. Thus, the sliding ring50ais held steady while the first and second arms30aand40disposed therein are advanced or retracted as desired.

In accordance with one aspect, a physician need not deploy the first clip device20aat this time. Rather, the first clip device20amay be moved between the open state ofFIG. 3, and a state that is at least partially closed, any number of times before final deployment. For example, a physician may at least partially close the first clip device20aby proximally retracting the stylet90, and therefore the first and second arms30aand40a, relative to the sliding ring50a, thus forcing the distal ends34aand44acloser together. However, before the distal ends34aand44aare locked closed within the sliding ring50a, the physician may distally advance the stylet90, thus distally advancing the first and second arms30aand40arelative to the sliding ring50aand re-opening the first clip device20a, e.g., for alternative positioning or grasping. Advantageously, in this manner, the first clip device20amay move between the open and closed states any number of times before final deployment.

Referring now toFIG. 4, if a physician wishes to securely close the first clip device20awith tissue therein, the stylet90and the first clip device20aare retracted tightly relative to the inner catheter70that is holding the sliding ring50a. Alternatively, the inner catheter70and outer catheter80may be advanced distally in tandem, while the stylet90is held steady. The result in either case is that the sliding ring50ais translated distally relative to the first and second arms30aand40awith enough force, as shown inFIG. 4, thereby securely closing the first clip device20a.

Referring now toFIG. 5, in a next step, the outer catheter80is proximally retracted with respect to the inner catheter70, such that the distal end84of the outer catheter80is positioned proximal to the wedge member92. At this time, the wedge member92is no longer radially constrained and the flexible distal region75of the inner catheter70may move radially outward to remove the constriction79, as depicted inFIG. 5. The sliding ring50ais no longer engaged in a friction fit with the inner catheter70.

The stylet90is then advanced distally relative to the inner catheter70to cause the distal ends34band44bof the first and second arms30band40b, respectively, of the second clip device20bto extend distal to the inner catheter70. At this time, the connection between the first and second arms30band40bof the second clip device20band the proximal retainer64aof the first clip device20ais exposed, thereby allowing the first and second clip devices20aand20bto detach from engagement with one another, as shown inFIG. 5.

After deployment of the first clip device20a, but before deployment of the second clip device20b, the sliding ring50bof the second clip device20bmay be aligned with the distal region75of the inner catheter70, in the manner explained inFIG. 2above for the first clip device20a. The sequence of deployment described inFIGS. 2-5then may be carried out for the second clip device20b. Advantageously, in this manner, any number of clip devices may be sequentially loaded into the lumen78of the inner catheter70and deployed, one at a time, without the need to remove the inner and outer catheters70and80from the patient's body and individually re-load clip devices, thereby saving operating time.

Referring toFIG. 6, and as noted above, the flexible distal region75of the inner catheter70may be selectively moved in a radially inward direction by providing a plurality of slits77formed in the flexible distal region75. In the embodiment shown, four slits77are formed in the distal end74of the catheter70and extend in tapered manner in a distal to proximal direction. The four slits77may be radially spaced apart around the circumference of the catheter70. The one or more wedge members92may be attached to the flexible distal region75at one or more locations between the slits77. While four illustrative tapered slits77are shown inFIG. 6, it will be appreciated that greater or fewer slits may be employed, and they may comprise different shapes and configurations than depicted.

Referring now toFIGS. 7-10, an alternative delivery system and sequence of deployment for at least one clip device is shown. InFIGS. 7-10, an alternative first clip device120ais similar to the first clip device20adescribed above, with a main exception that proximal ends132aand142aof first and second arms130aand140a, respectively, are integrally formed into a proximal retainer164ain the shape of a loop member, and therefore the proximal securement member60aofFIGS. 1-5is omitted. In this manner, the first clip device120amay be formed from one continuous wire that is looped around at its proximal end, and where the continuous wire is bent to form distal ends134aand144a, as shown inFIG. 7and described further inFIG. 12below.

The proximal retainer164ain the shape of the loop member has an outer diameter that is larger than the inner diameter of the sliding ring50a, thereby limiting proximal movement of the sliding ring50a. As in the embodiment ofFIGS. 1-5, the sliding ring50ais otherwise dimensioned to slide over the first and second arms130aand140a, toward the distal ends134aand134bof the first and second arms130aand140a, respectively, causing the arms to move to a closed position. The first clip device120ahas a delivery state, an open state, and a closed state, similar to the first clip device20adescribed above.

The alternative delivery system ofFIGS. 7-10comprises a catheter170having a lumen178, and has an inner diameter that is generally larger than an outer diameter of the first and second clip devices20aand20bin the delivery state, thereby allowing the first and second clip devices20aand20bto be loaded within the lumen78of the catheter70as shown inFIG. 1. Notably, in this embodiment, an outer catheter is omitted.

The catheter170comprises a distal end174and a tapered distal region175. Preferably, at least one slit177is formed in the tapered distal region175, as shown inFIG. 10, to permit the radial flexibility along the distal region175.

In one exemplary method, the first and second clip devices120aand120bmay be loaded sequentially such that the first clip device120ais loaded distal to the second clip device120bwithin the lumen178of the catheter170, as shown inFIG. 7. The stylet90may be positioned in the lumen178at a location proximal to the second clip device120b. In use, the first and second clip devices120aand120bmay be loaded within the catheter170such that the distal ends134band144bof the second clip device120bsecurely engage the proximal retainer164aof the first clip device120a. Further, the retainer92of the stylet90engages the proximal retainer164bat the proximal end of the second clip device120b, as shown inFIG. 7. Accordingly, proximal and distal advancement of the stylet90causes a corresponding movement of the first and second clip devices120aand120b.

Notably, the catheter170has a first inner diameter D1at a location proximal to the tapered distal region175, and has a smaller second inner diameter D2at the distal end174, as shown inFIG. 10, such that the taper reduces the inner diameter from D1to D2. The sliding ring50ahas an outer diameter having a size dimension between the first and second inner diameters D1to D2of the catheter170. In the delivery state shown inFIG. 7, absent significant forces imposed thereon, the tapered distal region175serves to retain the first clip device120ainside of the catheter170and prevents inadvertent piercing by the arms130aand140a.

Referring toFIG. 8, in a next step, the stylet90is advanced distally, relative to the catheter170, to cause distal advancement of the second clip device120band corresponding distal advancement of the first clip device120ain an abutting manner. The stylet90is advanced distally until the sliding ring50aof the first clip device120aabuts the tapered distal region175and is ultimately advanced distal to the tapered distal region175with a sufficient force. The slit177of the tapered distal region175allows the distal end174of the catheter170to flex upon application of the sufficient force imposed by the sliding ring50a, and further, the tapered distal region175may be formed of a material, such as molded plastic, that facilitates such flexing upon application of the sufficient force by the sliding ring50a. At this time, the distal ends134aand144aof the arms130aand140a, respectively, of the first clip device120aare advanced distally beyond the distal end174of the catheter170, and when unconstrained, tend to bow in a radially outward direction spaced apart from one another, as depicted inFIG. 8.

While the sliding ring50ais disposed just distal to the tapered distal region175of the catheter170, the proximal retainer164aof the first clip device120ais retained within the lumen178of the catheter170, as shown inFIG. 8. The tapered distal region175of the catheter170may be biased such that it tends to close around the proximal retainer164aof the first clip device120a. At this time, the distal end174of the catheter170abuts a proximal edge of the sliding ring50a, as depicted inFIG. 8. Since the second inner diameters D2of the catheter70is less than an outer diameter of the sliding ring50a, the sliding ring50ais prevented from being pulled back into the lumen178of the catheter170.

The stylet90may be proximally retracted to at least partially close the first clip device120a. However, before the distal ends134aand144aare locked closed within the sliding ring50a, the physician may proximally or distally advance the stylet90gently, thus partially closing and re-opening the first and second arms130aand140a.

Referring toFIG. 9, if a physician wishes to securely close the first clip device120awith tissue therein, the stylet90and the first clip device120aare retracted tightly relative to the catheter170. Alternatively, the catheter170may be advanced while the stylet90is held steady. The result in either case is that the sliding ring50ais translated distally relative to the first and second arms130aand140a, as shown inFIG. 9, thereby securely closing the first clip device120a.

Subsequently, the stylet90is then advanced distally relative to the catheter170to cause the distal ends134band144bof the arms130band140b, respectively, of the second clip device120bto extend distal to the catheter170. At this time, the connection between the first and second arms130band140bof the second clip device120band the proximal retainer164aof the first clip device120ais exposed, thereby allowing the first and second clip devices120aand120bto detach from engagement with one another in a manner similar to the embodiment ofFIG. 5.

The sequence of deployment described inFIGS. 7-9then may be carried out for the second clip device120b. Advantageously, in this manner, any number of clip devices may be sequentially loaded into the lumen178of the catheter170and deployed, one at a time, without the need to remove the catheter170from the patient's body and individually re-load clip devices, thereby saving operating time.

Referring now toFIG. 11, a loading cylinder190may be used in conjunction with either the embodiment ofFIGS. 1-6orFIGS. 7-10to facilitate fast and efficient loading or reloading of one or more clip devices. In the embodiment ofFIG. 11, the loading cylinder190comprises proximal and distal ends192and194, respectively, and a lumen198extending therebetween. The loading cylinder190may comprises inner and outer diameters that are identical to inner and outer diameters of the inner catheter70ofFIGS. 1-6or the catheter170ofFIGS. 7-10. Optionally, an engagement mechanism (not shown) may be provided to selectively couple the distal end194of the loading cylinder190with the proximal end172of the catheter170, to thereby ensure a correct alignment between the lumen198of the loading cylinder190and the lumen178of the catheter170.

In the example ofFIG. 11, two additional clip devices120cand120d, which are identical to the clip devices120aand120bofFIGS. 7-9, are loaded into the lumen198of the loading cylinder190as shown. The proximal retainer164dof the clip device120dmay extend just outside of the proximal end192of the loading cylinder190, as shown inFIG. 11, for subsequent engagement with a retainer92′ of an alternative stylet90′. The alternative stylet90′ is similar to the stylet90described above, with an exception that the retainer92′comprises arms95and96, which are similar in structure to the distal ends134aand144aof the first clip device120a.

In use, a physician may deploy the clip devices120aand120bin the manner described inFIGS. 7-9above. The loading cylinder190, carrying additional clip devices120cand120d, may be provided in the operating room. If the additional clip devices120cand120dare needed, the stylet90′ is retracted from within the lumen178of the catheter170, and may be withdrawn towards a sheath98as depicted inFIG. 11. The distal end194of the loading cylinder190then is aligned with the proximal end172of the catheter170, such that the lumen198of the loading cylinder190is aligned with the lumen178of the catheter170. The arms95and96of the retainer92′ of the stylet90′ then are joined to the proximal retainer164dof the clip device120dand urged distally into the loading cylinder190. Distal advancement of the stylet90′ causes corresponding distal advancement of the clip devices120cand120dthrough the lumen178of the catheter170, and the deployment of the clip devices120cand120dmay be carried out in the manner described above. Advantageously, the endoscope and catheters can remain in place within the body of the patient, retaining access to the bleeding site, and facilitating a faster procedure. The catheters70and170described above can be reloaded as many times as needed using one or more loading cylinders190. Moreover, different loading cylinders190can be provided with different clip styles.

Referring now toFIGS. 12-15, features of various possible clip designs are shown. InFIG. 12, the clip device120aof the embodiment ofFIGS. 7-10is shown in isolation. In one embodiment, the clip device120ahas a length in the delivery state of between about 10 mm to about 25 mm. In the open state, the distance between the distal ends134aand144aof the first and second arms130aand140a, respectively, may be between about 6 mm to about 10 mm. The wire forming the clip device120amay comprise a flat wire having a width of about 0.8 mm to about 1.0 mm, and a thickness of about 0.1 mm to about 0.2 mm. When used in conjunction with a delivery system as shown inFIGS. 1-6orFIGS. 7-10, the clip device120aand associated sliding ring50acan fit down an endoscope channel having a 2.8 mm or 3.2 mm diameter. As noted above, the clip device120acan be formed of any suitable material such as nitinol or another material that may be biased to assume the open state shown inFIG. 12upon removal from a delivery catheter, and optionally may be formed of a resorbable material.

InFIG. 13, an alternative clip device120a′ is formed from a wire that is bent to form the first and second arms130aand140a, as explained inFIGS. 7-9andFIG. 12above, however an additional wire segment is provided and forms a third arm150ahaving a proximal end152aand a distal end154a. A three-prong clip device120a′ therefore is provided. The proximal end152aof the third arm150amay be soldered to a portion of the loop formed by the proximal ends132aand142aof the arms130aand140a, respectively, thereby forming a proximal retainer164a. In a further alternative, a clip device may be similar to the clip device120a′, but may comprise a fourth arm, whereby the four arms may be equally spaced apart about 90 degrees from one another, or variably spaced apart at other distances from one another.

InFIG. 14, an alternative clip device120a″ is substantially identical to the clip device120a, with the exception that an additional wire is disposed inward of the wire forming the first and second arms130aand140a. The additional wire forms third and fourth arms130a″ and140a″ having proximal ends132a″ and142a″, respectively. The proximal ends132a″ and142a″ form a loop member disposed inside of the loop member formed by the proximal ends132aand142aof the first and second arms130aand140a, respectively, as shown inFIG. 14, to form a proximal retainer164a″. Further, the third and fourth arms130a″ and140a″ have distal ends134a″ and144a″, which may be slightly offset from the distal ends134aand144aof the first and second arms130aand140a, respectively, as shown inFIG. 14.

InFIG. 15, an alternative clip device220is similar to the clip device120ain that one wire is bent to form first and second arms230and240having proximal ends232and234, respectively, which are coupled together to form a proximal retainer264in the shape of a loop member. The first and second arms230and240further comprise distal ends234and244, respectively. In this embodiment, the wire forming the first and second arms comprises a round cross-sectional shape. In order to provide a larger and sharper surface area to engage tissue, grasping members250aand250bare coupled to exterior surfaces of the distal ends234and244of the first and second arms230and240, respectively. The grasping members250aand250bmay be coupled to the first and second arms230and240using a solder, weld, mechanical connection, or other suitable technique. Preferably, the grasping members250aand250bcomprise sharpened distal tips255that are bent radially inward to securely engage tissue. It will be appreciated that where flat wire cross-sections are depicted herein, round wire cross-sections may be provided, and vice versa.

While various embodiments of the invention have been described, the invention is not to be restricted except in light of the attached claims and their equivalents. Moreover, the advantages described herein are not necessarily the only advantages of the invention and it is not necessarily expected that every embodiment of the invention will achieve all of the advantages described.