Expandable Cap for Endoscopic Closure Device

Abstract

The assembly for the closure device includes a cap having a distal portion with a recess for receiving tissue and a proximal portion that fits onto the surface of the endoscope. The proximal portion includes a fold between a first region and a first end of a second region. The cap expands from a folded state in which the angle of the first region relative to the longitudinal axis of the endoscope is minimized to an expanded state in which the angle is increased. Based on the angle and reflectivity of the first region, the field of view of the endoscope camera on the surface is increased in the expanded state relative to the folded state. The device captures tissue when the cap is in the expanded state via an actuating mechanism that extends distally through the channel of the scope.

Description

Technical Field

[0001] The present disclosure relates to an endoscopic tissue grasping device, and more particularly to an extendable and / or expandable cap for an endoscopic device that enables deployment of the tissue grasping device while providing better visualization for an endoscopic camera. The present disclosure claims priority to U.S. Provisional Patent Application No. 63 / 379,394, filed on October 13, 2022, the disclosure of which is incorporated herein by reference.

Background Art

[0002] Hemostatic clips are used to close various openings in internal tissues. In the case of larger openings or when treating larger tissue defects, over-the-scope clips (OTSCs) are frequently used because they can capture a larger volume of tissue than clips that pass through the working channel of an endoscope. OTSC devices often include an over-the-scope cap that is attached and pre-mounted at the distal end of the endoscope on the clip. By applying suction or grasping means to draw the tissue into the internal volume of the cap, a clip for grasping the tissue drawn into the cap can be deployed from the distal end of the cap. Similarly, by deploying a ligation band from a cap attached to the distal end of the endoscope, the band can be released from the cap and the tissue drawn into the cap can be constricted around its circumference.

[0003] Both of these devices can obstruct a portion of the field of view of the endoscopic vision system, so it can be difficult for the user to clearly visualize the target tissue and confirm that the desired portion of the tissue has actually been drawn into the cap before the clip or band is deployed. Clips or bands deployed in the wrong position or that do not fully capture the desired tissue may need to be removed and / or repositioned.

Summary of the Invention

[0004] The present disclosure relates to an assembly for an endoscopic closure device including a cap. The cap includes a distal portion having a recess configured to receive a target tissue for capture by the closure device, and a proximal portion sized and shaped to fit onto a distal surface of an endoscope. The proximal portion is formed of a flexible material and includes at least one fold between a first region and a first end of a second region. The distal portion and the proximal portion are connected at a junction between a proximal end of the distal portion and a second end of the second region. The cap extends from a folded state in which an angle of the first region relative to a longitudinal axis of the endoscope is minimized to an extended state in which the angle is increased. An inner surface of the first region is reflective, and based on the angle and reflectivity of the first region, a field of view of an endoscope camera on the distal surface of the endoscope is increased in the extended state relative to the folded state. The closure device is deployable to capture the target tissue received in the recess of the distal portion when the cap is in the extended state via an actuating mechanism extending through an operating channel of the endoscope into the distal portion.

[0005] In one embodiment, in the folded state, a distance between the distal surface of the endoscope and the proximal end of the distal portion is minimized and a curvature of the fold is maximized, and in the extended state, the distance is increased and the curvature of the fold is decreased, thereby increasing the field of view of the endoscope camera.

[0006] In one embodiment, a proximal end of the first region of the proximal portion has a size and shape that fits snugly outside the endoscope at a position proximal to the distal surface of the endoscope, and a distal end of the first region at the fold extends to a position distal to the distal surface of the endoscope. The second region extends proximally from the first end at the fold to the second end at the junction.

[0007] In one embodiment, in the folded state, the joint is adjacent to the distal surface of the endoscope, and in the extended state, the distance is provided between the distal surface of the endoscope including the endoscope camera and the proximal end of the distal portion by the joint translating distally.

[0008] In one embodiment, the cap is biased to the extended state, and the distance between the distal surface of the endoscope and the proximal end of the distal portion is reduced by operating a pull string extending through the working channel of the endoscope to pull the distal portion of the cap proximally. When the distance is reduced, the curvature of the folded portion is increased by the flexible material of the proximal portion and the angle of the first region with respect to the longitudinal axis of the endoscope is decreased.

[0009] In one embodiment, the cap is biased to the folded state, and the distance between the distal surface of the endoscope and the proximal end of the distal portion is increased by operating a flexible member extending through the working channel of the endoscope to push the distal portion of the cap distally. When the distance is increased, the curvature of the folded portion is decreased by the flexible material of the proximal portion and the angle of the first region with respect to the longitudinal axis of the endoscope is increased.

[0010] In one embodiment, the cap further has a function of preventing the target tissue captured in the recess of the distal portion from extending proximally with respect to the proximal end of the distal portion.

[0011] In one embodiment, the function includes a partition fin, web, strand, or grid extending laterally at the proximal end of the distal portion. In one embodiment, the function includes a transparent plate extending laterally at the proximal end of the distal portion, and the plate includes a hole for passage of the closing device.

[0012] In one embodiment, the actuating mechanism is operable from the proximal end of the endoscope. In one embodiment, the actuating mechanism of the closing device and the extending mechanism of the cap are interlocked such that extending the cap triggers the actuating mechanism to deploy the closing device.

[0013] In one embodiment, the extending mechanism includes a flexible member that extends through the working channel of the endoscope and pushes the distal portion of the cap distally, and when the distal portion of the cap is pushed distally to a trigger point, the closing device is deployed.

[0014] In one embodiment, the extending mechanism includes a pull string that extends through the working channel of the endoscope, and when the pull string is pulled during extension of the cap, a force to deploy the closing device is applied by the pull string.

[0015] In one embodiment, the closing device is in contact with the first region, and the closing device is deployed as the first region extends. In one embodiment, the actuating mechanism includes at least one wire for deploying the closing device.

[0016] In one embodiment, the closing device includes a clip device. In one embodiment, the closing device includes a ligating band device. In one embodiment, the proximal portion includes two or more folding portions, and in the folded state, the distance between the distal surface of the endoscope and the proximal end of the distal portion is minimized and the curvature of each folding portion is maximized, and in the extended state, the distance is increased and the curvature of each folding portion is decreased, thereby increasing the field of view of the endoscope camera.

[0017] In one embodiment, in the extended state, the first region has a flare shape. In one embodiment, in the extended state, the first region has a frustum shape. The present disclosure also relates to an assembly for an endoscopic closure device. The assembly includes a cap having a distal recess configured to receive a target tissue for capture by the closure device, and a proximal recess having a size and shape that fits onto the distal face of the endoscope and is separated from the distal recess by a partition. The partition has at least one hole for a catheter, and the distal recess is open to the interior of the catheter that extends through the proximal recess and the working channel of the endoscope. The cap translates from a first position where the proximal recess is attached to the endoscope to a second position where the cap is moved distally by a distal force applied to the catheter. The closure device is deployable to capture the target tissue received within the distal recess when the cap extends to the second position via an actuating mechanism that extends into the distal recess through the interior of the catheter.

[0018] In one embodiment, the catheter extends proximally from the partition, through the proximal recess and the working channel, to a proximal position relative to the proximal end of the working channel.

[0019] In one embodiment, the catheter terminates at the proximal end of a fixture for attachment to aspirate a tube. In one embodiment, the aspiration is applied to the distal recess via the catheter and is maintained when the cap extends to the second position.

[0020] In one embodiment, the aspiration is maintained via a slot that extends along the catheter aligned with an aspiration opening at the proximal end of the endoscope. In one embodiment, the aspiration is maintained via an auxiliary aspiration device that extends through the working channel.

[0021] In one embodiment, the actuating mechanism includes a pull string that extends through the catheter. In one embodiment, the actuating mechanism includes a pull string that extends through the working channel outside the catheter, and the cap includes a further hole sized and shaped to allow the pull string to pass through the partition.

[0022] In one embodiment, the closure device includes a clip device or a ligation band device.

Brief Description of the Drawings

[0023]

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[0024] The present disclosure can be further understood with reference to the following description and the accompanying drawings. Like elements are referred to with like reference numerals. The present disclosure relates to an over-the-scope cap that can be extendable and / or expandable to increase the field of view available for an endoscope camera. Exemplary caps can be used in conjunction with various tissue grasping devices, including over-the-scope clips (OTSCs), ligation bands, etc., to enable proper placement of the tissue grasping device prior to deployment.

[0025] In one aspect, the cap includes a flexible proximal portion having a reflective surface, the proximal portion being capable of extending such that a user (e.g., a physician) can visualize the area surrounding the distal portion of the cap. In another aspect, the cap is connected to or formed with an elongate flexible catheter that extends through the working channel of the endoscope, and the catheter is capable of translating the cap from a retracted position where the cap is drawn toward the distal end of the endoscope to an extended position where the cap projects distally away from the distal face of the endoscope. In both of these exemplary aspects, the cap enables the user to view surrounding tissue that may have been obscured by the target tissue received within the distal portion of the cap or within a pocket, etc.

[0026] Existing methods for closing tissue perforations or defects involve placing clips at the location of the defect using an over-the-scope clip (OTSC) device. These devices typically consist of a cap attached to the end of an endoscope and a clip pre-mounted on the cap. The endoscope is generally maneuvered to a target site within the body, and then suction or grasping means are applied to draw the target portion of the tissue (e.g., via the open distal end of the cap) into the internal channel of the cap. Next, the clip is pushed out from the distal end of the cap, causing the clip to close and grasp the tissue within the cap. Also, the over-the-scope cap is used in a similar manner as that employed in ligation band devices, and for example, one or more flexible ligation bands can be placed around the target tissue drawn into the channel of the cap in the same way as described above for OTSC, for purposes such as stopping bleeding or performing endoscopic mucosal resection (EMR).

[0027] In each of these applications, similar visualization problems occur. For example, when applying a ligation band or an OTSC clip to tissue, it can be difficult to visually determine whether the entire target portion of the tissue being treated has been drawn into the cap and whether the deployed clip or band is clamping the tissue as desired. The target tissue, when drawn into the cap, can obscure the field of view from the endoscope camera, impairing visualization of the surrounding tissue. If the clip is placed in the wrong position, removal and / or repositioning may be required.

[0028] According to various exemplary embodiments described herein, an over - the - scope cap can be extended or extended to improve the visualization of a target region and surrounding tissue via an endoscopic vision system. In some embodiments, the cap includes an extensible cross - section having a fold or pleat biased towards a folded state, an extended state, or a partially extended state. In one embodiment, as will be described in more detail below, some regions of the cap are transparent while other regions are reflective to extend the field of view of the endoscopic camera. In other embodiments, the cap is translated distally away from the distal face of the endoscope through a long flexible catheter to improve the visualization of the tissue outside the cap via the endoscopic camera. That is, when the cap extends distally away from the distal end of the endoscope, the tissue drawn into the cap is separated distally from the vision system at a greater distance, resulting in less occlusion of the vision system's field of view and making it possible to improve the visualization of the tissue drawn into the cap and the tissue surrounding this captured tissue.

[0029] According to one aspect of these exemplary embodiments, the scope cap includes at least one region formed of a flexible material, and this region includes at least one foldable or extensible fold or pleat. Some regions of the cap in these embodiments are transparent while other regions are reflective. In these embodiments, an exemplary cap may enable a user to control the distance between an optical lens and the distal end of the scope cap. The reflective portion of the cap is configured to provide visualization of the tissue around the cap.

[0030] Figures 1-3 illustrate an exemplary assembly 100 for an endoscopic closure device, the assembly 100 including a scope cap 102 attachable to the distal end 142 of an endoscope 140, the cap 102 being expandable from a folded state to a partially or fully extended state according to various exemplary embodiments. The cap 102 includes a distal portion 104 for capturing tissue therein and an expandable proximal portion 108 attached to the distal end of the endoscope 140. The proximal portion 108 and the distal portion 104 of this embodiment are connected to each other at a junction 106. In further embodiments, the proximal portion 108 may be integrally formed with the distal portion 104.

[0031] A cross-section of the cap 102 of this embodiment, including the proximal portion 108, the distal portion 104, and the junction 106, is substantially circular at any given location along the length of the cap 102. The distal portion 104 may be cylindrical, and the junction 106 represents a circular transition point between the distal portion 104 and the proximal portion 108. The junction 106 and / or the distal portion 104 may have a cross-section substantially similar to the cross-section of the endoscope 140. As will be described in more detail below, the proximal portion 108 may have a substantially cylindrical (or slightly conical) region in the folded state, while this region may have a conical shape in the extended state.

[0032] One skilled in the art can understand that the shape of the cap 102 or various parts of the cap 102 can be changed according to the geometry of the endoscope 140 to which it is attached, or the shape of the target part of the tissue to be ligated, etc. That is, the cap 102 may include a proximal portion 108 configured to fit the size and shape of the distal end of the endoscope to which it is attached. Thus, if the endoscope has a non-circular distal end, the proximal portion 108 of the cap 102 is also non-circular. Further, depending on the shape and size of the tissue to be captured, the shape and / or size of the distal portion 104 of the cap 102 may have a different shape from the proximal portion 108. For example, the distal portion 104 may be elongated along any desired axis if it is desired to capture the tissue along an elongated shape, as opposed to a circular tissue portion that can be captured within the circular distal portion 104.

[0033] The proximal portion 108 is formed of a flexible material and has a size and shape that can slide (e.g., by friction fitting) on the distal end 142 of the endoscope 140 while maintaining a state away from the optical part (e.g., camera and illumination) and the working channel (e.g., working channel 144 and mechanism for the optical part) of the endoscope 140, as can be understood by one skilled in the art. The proximal portion 108 of this embodiment includes a first region 110 that is snugly attached to the outside of the endoscope 140 at a position proximal to the distal end 142 of the endoscope 140 at the proximal end 112.

[0034] The inner surface of the proximal end 112 of the first region 110 has a shape and size corresponding to the shape and size of the outer surface of the endoscope 140, which typically has a circular cross-section. However, the size and shape of this proximal portion can be appropriately changed as desired to enable the mounting of the cap 102 onto the endoscope 140. The distal end of the first region 110 forms a bend (or fold) 114 together with the first end of a second region 116 that connects the proximal portion 108 to the distal portion 104 (extending proximally from the fold 114 to the junction 106). This bending structure, including the first region 110, the fold 114, and the second region 116, is referred to herein as a "pleat".

[0035] In the example shown in FIGS. 1-3, the cap 102 includes a single fold 114 or pleat. However, in alternative embodiments, the cap 102 may include multiple folds or pleats. As used herein, the term "pleat" refers to a circumferential (e.g., circular / cylindrical or conical) region that is folded upon itself to define a separation line between two circumferential regions that extend in opposite directions (i.e., one extending distally and the other proximally).

[0036] As shown in FIGS. 1 and 2, when the cap 102 is in the folded state, the first and second regions 110, 116 of the proximal portion 108 extend in a direction substantially parallel (or inclined at a slight angle) to the longitudinal axis of the endoscope 140 at the distal end 142 of the endoscope 140 such that the angle formed by the first and second regions 110, 116 is minimized. In other words, the first region 110 of this embodiment is substantially cylindrical or presents a frustum of a cone with a small apex angle. The first region 110 extends substantially distally from the proximal end 112 to the fold 114. In the folded state, the fold 114 has a bend (e.g., maximum curvature) of about 180 degrees such that the second region 116 extends substantially proximally from the fold 114 to the junction 106 that connects the proximal portion 108 to the distal portion 104. In the folded state, the junction 106 that defines the proximal end of the distal portion 104 is adjacent to the distal end 142 of the endoscope 140.

[0037] As shown in FIG. 3, when the cap 102 is in the extended (or partially extended) state, the first region 110 extends from the substantially cylindrical shape (in the folded state described above) to a frustum of a cone having a maximum apex angle of about 45 degrees in one embodiment, e.g., a flare shape. The angle of the first region 110 with respect to the longitudinal axis of the endoscope 140 is half of the apex angle of the frustum of the cone. However, this angle of the first region 110 may be changed. Thus, as the curvature of the fold 114 decreases from the maximum curvature (e.g., 180 degrees) to a lower curvature (e.g., 45 degrees), the field of view of the endoscope camera is increased.

[0038] As will be described in more detail below, the angle of the first region 110 in the extended state is selected in this embodiment to widen (e.g., increase) the field of view of the endoscope camera located in the region 146 at the distal end 142 (e.g., the distal surface) of the endoscope 140. The range of extension of the first region 110 is, as will be described in more detail below, at the discretion of the operating physician so that optimal visualization of the tissue can be obtained from a viewpoint outside the initial circumference of the cap 102, and is controlled by the user operating the endoscope 140 such that the angle of the first region 110 is less than its maximum angle.

[0039] As the cap 102 is extended and the angle of the first region 110 increases, the fold 114 at the distal end of the first region 110 is radially pushed outwards to a circumference larger than the initial circumference of the fold 114 in the folded state. As the circumference of the fold 114 increases, the bend in the fold 114 is reduced from approximately 180 degrees in the folded state to approximately 150 degrees such that the angle between the first region 110 and the second region 116 in the fold 114 is approximately 30 degrees. One skilled in the art can recognize that the angle representing the shape of the proximal portion 108 in the extended state can be variously changed according to, for example, the length of the first region 110, the length of the second region 116, the flexibility of the proximal portion 108, etc.

[0040] As shown in FIG. 3, as the proximal portion 108 extends, the location of the joint 106 between the proximal portion 108 and the distal portion 104 translates distally, disengaging the proximal end of the distal portion 104 from contact adjacent to the distal end 142 of the endoscope 140. One skilled in the art can recognize that as the angle of the first region 110 increases, the distance between the distal portion 104 and the distal end 142 of the endoscope 140 also increases.

[0041] The distal portion 104 may be formed of a flexible material, may have a cylindrical shape and a circumference similar to that of the circumference of the endoscope 140, or may have different shapes and sizes as desired. The distal portion 104 has an open surface on its distal end (i.e., including an open distal end that opens into the channel within the cap 102) so as to be able to draw tissue into the cap 102, and is transparent at its proximal end (at the junction 106) so as to provide visualization via the endoscope camera when the cap 102 is in a folded state or an extended state (assuming that the tissue has not yet been received within the distal portion 104 and / or that the visualization of the endoscope camera is blocked).

[0042] The cap 102 may be biased towards either a folded state (closed) or an extended state (open) (i.e., when no actuating force is applied to the cap 102, the cap 102 assumes the state in which it is biased). In one embodiment, the cap 102 is biased towards the open state, and the actuating force for maintaining the cap 102 in the closed state is provided, for example, via a pull string (e.g., a suture thread) that extends through the working channel 144 of the endoscope 140 and is attached to the junction 106 or other location with respect to the distal portion 104 of the cap 102.

[0043] By using this pull string to draw the distal portion 104 proximally, the pleats can be closed by bringing the junction 106 into contact with the distal end 142 of the endoscope 140 (or by bringing it into contact with any most proximal position of the junction 106). When this pull string is released, the cap 102 becomes extensible. The tension can be applied to the pull string, for example, proximally with respect to the proximal end of the endoscope 140, or via the proximal support structure of the proximal end, or manually by the operating physician, during the deployment of the endoscope 140 to the target site.

[0044] In another embodiment, the cap 102 may be biased towards the closed position, and the actuating force may be applied through a flexible member 120, such as a rod, that extends through the working channel of the endoscope 140 as shown in FIGS. 2 and 3 and is attached to the junction 106 or elsewhere on the distal portion 104. Then, by using this member 120 to push the distal portion 104 distally, the pleats can be opened (or partially opened). When this member 120 is retracted, the cap 102 can be folded under its own bias and return to the closed position.

[0045] In one embodiment, the inner surface of the first region 110 of the proximal portion 108 is reflective while the second region 116 is transparent. When the cap 102 is extended, the distal portion 104 moves away from the distal end 142 of the endoscope 140. The reflective surface of the first region 110 changes the field of view of the endoscope camera (e.g., image sensor) when the first region 110 is angled with respect to the longitudinal axis of the endoscope 140 such that tissue outside the initial circumference of the cap 102 can be visualized by its reflection. If tissue has been aspirated into the distal portion 104 of the folded cap 102 and is covering the image sensor, the tissue can be pulled away from the optical lens (or equivalently, the endoscope 140 is pulled proximally from the tissue), allowing the area around the tissue to be more clearly visualized. The cap, in the extended state, can be radially and longitudinally extended to provide better visualization of the space.

[0046] To prevent the tissue from continuously contacting the lens, i.e., to limit the range within which the tissue can enter proximally within the cap 102, additional features can be added to the cap 102. This feature can include, for example, partition fins, webs, strands that bisect the cap lumen and are tensioned during extension, a grid extending laterally at the proximal end of the distal portion 104, or an optically transparent plate. This feature can be integrated and / or actuated during extension, for example, to translate away from the optical lens during extension of the cap 102. When a transparent plate is used, holes can be provided in the transparent plate for the passage of a grasper or aspirator.

[0047] The deployment of a ligating band or clip (e.g., OTSC) can be achieved by a pull-string technique known in the art. Alternatively, this deployment can be achieved by one of the following techniques.

[0048] In one embodiment, an actuation of extending the cap can be used to trigger the deployment. In a first extension stage, while the proximal portion of the cap is extended to improve visualization of the target tissue, the band or clip can remain held within or on the cap. In a second extension stage, the band / clip can be moved relative to the distal end of the cap by biasing the band / clip by an element that applies a force to the band / clip. In one example, by using a pull-string technique, when the cap is extended beyond a control point, tension is automatically applied to this string to apply a force to the band / clip, biasing the band / clip distally for deployment. That is, as would be understood by one of ordinary skill in the art, when the cap 102 is extended and the band / clip is moved distally, and the band / clip passes through a point where the biasing of the band / clip itself causes the band / clip to contract, increasing the tension on the string until the band / clip moves distally from the cap 102 by its own biasing, the string is held in the taught state. In one embodiment, the extension mechanism of the cap 102 can be fixed to an actuation mechanism for deploying a closure device.

[0049] Figures 4 - 6 show an assembly 150 that includes the endoscope 140 and the cap 102 described in FIGS. 1 - 3, and further includes a clip device 152 according to an exemplary embodiment. In this example, as shown in FIGS. 4 and 5, when the cap 102 is in the folded state, the clip is biased towards the closed state and is constrained in the open and / or undeployed state by being stretched over the outer periphery of the cap 102. As the cap 102 is distally extended, a mechanism, such as member 120, at or near the proximal end of the distal portion 104 pushes the clip towards deployment, causing the clip to move away from the distal end of the cap 102 and no longer be held in the open state by the cap 102. As shown in FIG. 6, the clip snaps closed (into the closed state) under its own bias and clips the tissue that was previously retracted into the cap 102.

[0050] As described above, the cap 102 of one embodiment further includes at the joint 106 and / or the proximal end / surface of the distal portion 104 a function to prevent the captured tissue from extending proximally within the cap 102 beyond the desired closest point. Thus, as shown in FIG. 6, a gap 154 is maintained between the tissue within the cap and the endoscope camera at the distal end 142, thereby enabling the operating physician to inspect the area around the captured tissue. As described above, the cap 102 can be extended in a first stage to enable visualization and the clip can be closed / deployed in a second stage.

[0051] In another embodiment, contact of the clip with the extended portion of the cap causes the clip to be distally moved by the movement of the extension element. Using this concept, the extended portion can be configured to hold / suppress the tendency of the clip to deploy. That is, by the extended portion providing a stop that restrains the clip, when the extended portion is moved to remove the restraint on the distal movement of the clip on the cap 102, the clip deploys under its own bias.

[0052] The tendency for the clip to deploy may be caused by a slight taper angle with respect to the face of the cap 102 (i.e., the outer diameter of the cap 102 decreases as it approaches the distal end of the cap 102), and when the clip closes, the biasing force itself that closes the clip may pull the clip distally on this tapered surface. In this embodiment, the extension portion provides a shoulder or a diameter-expanded surface distally of the clip in the non-extended state, and when the extension portion is extended, the diameter decreases and the clip can move distally under its biasing force. In yet another embodiment, by using one or more wires, the clip can be pushed and / or pulled proximally or distally relative to the cap 102.

[0053] According to another aspect of these exemplary embodiments, the scope cap is connected to or formed with a long flexible catheter extending through the working channel of the endoscope, and this catheter is configured to translate the cap from a mounting position on the distal end of the endoscope to an extended position distal of the distal face of the endoscope. The exemplary cap includes a shallow recess or pocket on its proximal portion, isolated from a deep recess / pocket on its distal portion configured to receive and capture tissue. A deployment mechanism (e.g., a pull string) for a gripper (e.g., a clip) or a ligation band deploys the clip / band by extending through the flexible catheter into the distal pocket even when the cap is in the extended position.

[0054] Figures 7-9 illustrate an exemplary assembly 200 including a scope cap 202 attachable to the distal end 242 (e.g., distal face) of an endoscope 240 and translatable from a mounted position to an extended position. The cap 202 includes a distal portion 204 (e.g., distal recess or distal pocket) configured to capture tissue therein and a proximal portion 208 (e.g., proximal recess or proximal pocket) configured to attach to the distal end 242 of the endoscope 240. The proximal portion 208 and the distal portion 204 are separated and isolated from each other by a partition 206. The partition 206 includes a hole 210 sized to allow a catheter 230 to pass through the proximal portion 208 and enter the distal portion 204 and to terminate such that the inner diameter of the catheter 230 opens into the distal portion 204, enabling aspiration, clip / band deployment, and / or application of other mechanisms.

[0055] The proximal portion 208 has a size and shape that fits snugly on the distal end 242 of the endoscope 240 such that the partition 206 is adjacent to the distal end 242. One or more tubes (e.g., catheters) extend through the proximal portion 208 to an opening within the partition 206, opening the distal portion 204 to the inner diameter (ID) of the tube. In this example, the cap 202 includes a single elongate flexible catheter (e.g., catheter 230) that is open to the distal portion 204. The distal portion 204 has an open distal face, is isolated from the proximal portion 208, and is open to the ID of the catheter 230. The partition 206 between the proximal portion 208 and the distal portion 204 is transparent in this embodiment, allowing optical components (e.g., camera and illuminator) of the optical mechanism 246 to visualize the area when the scope cap 202 is mounted on the distal end 242.

[0056] When the cap 202 (e.g., the proximal portion 208) is fixed onto the distal end 242, the catheter 230 is sized to fit within and extend the length of the working channel (e.g., working channel 244) of the endoscope 240. The proximal end of the catheter 230 terminates at a junction at a point slightly outside the proximal end of the working channel. This junction is designed in one embodiment to be attached to a suction tube that is further proximally connected to a suction source (e.g., a pump), or is long enough to be connected directly to the suction source without intervening tubing. This prevents suction loss due to the gap between the inner diameter of the working channel and the outer diameter of the catheter 230.

[0057] The distal portion 204 may have a distal face that is pressed against the area of tissue where the operating physician desires to deploy a clip or band. The tissue can be drawn into the internal volume of the distal portion 204. At this point, if the operating physician desires to inspect the placement of the clip / band prior to deployment, the proximal end of the catheter 230 is advanced into the working channel of the endoscope 240. When this is done, the cap 202 moves away from the distal end 242 of the endoscope 240, enhancing visualization of the tissue outside the cap 202 via the optical mechanism 246. During this inspection, suction is maintained within the distal portion 204 so as not to lose the grasping force on the tissue.

[0058] Suction can be maintained in various ways within the cap 202. The device can utilize the original suction action provided by a standard endoscope by having a slot along the catheter 230 inside the working channel that aligns with the suction opening at the proximal end of the endoscope 240. Alternatively, the device can use an auxiliary suction device that enters from the end of the working channel. In either of these cases, the string in the conventional pull-string technique may pass either inside or outside the catheter 230 within the working channel. When the string is outside the working channel, a very small hole may be required in the partition 206 to allow the string to pass through the center of the cap 202 and into the distal portion 204. This small hole can provide the additional advantage of discharging the aspirated fluid and improving the suction of tissue.

[0059] By using the cap 202, the operating physician can more clearly visualize the deployment of the clip / band through the pull-string and perform proper placement of the clip / band by viewing the target tissue and the area surrounding the target.

[0060] Figure 10 shows an assembly 250 that includes the endoscope 240 and the cap 202 as described in FIGS. 7 - 9 and further includes a clip device 252 according to an exemplary embodiment. In this example, as shown in FIG. 10, when the cap 202 is in the extended position, the clip device 252 can be actuated by a pull-string 254 that extends through the catheter 230 to a position proximal to the endoscope 240. The cap 202 of this embodiment further includes a mechanism 256, such as a bracket, outside the distal portion 204 to hold the pull-string 254.

[0061] The operating physician may apply suction to draw the target portion of the tissue into the distal portion 204 before deploying the clip device 252. Next, in order to ensure that the desired tissue portion is correctly captured, the physician may translate the cap 202 distally via the catheter 230 to widen the field of view of the endoscopic vision system and more clearly visualize the tissue surrounding the target tissue. When the tissue is sufficiently captured, the physician may deploy the clip device 252 via the pull string 254.

[0062] One of ordinary skill in the art will appreciate that changes may be made to the above-described embodiments without departing from the concepts of the present invention. The structural features and methods associated with one of the above embodiments can also be incorporated into other embodiments. Accordingly, it is understood that the present invention is not limited to the particular embodiments disclosed, but that modifications are also included within the scope of the invention as defined by the appended claims.

Claims

1. An assembly for an endoscopic closure device, comprising a cap including a distal portion having a recess configured to receive a target tissue for capture by the closure device, and a proximal portion sized and shaped to fit onto the distal surface of an endoscope, wherein the proximal portion is formed of a flexible material and includes at least one fold between a first region and a first end of a second region, and the distal portion and the proximal portion are connected at a junction between the proximal end of the distal portion and the second end of the second region; the cap extends from a folded state in which the angle of the first region with respect to the longitudinal axis of the endoscope is minimized to an extended state in which the angle is increased, and an inner surface of the first region is reflective, and based on the angle and reflectivity of the first region, a field of view of an endoscope camera on the distal surface of the endoscope is increased in the extended state relative to the folded state; the closure device is deployable, via an actuating mechanism extending through a working channel of the endoscope into the distal portion, to capture the target tissue received in the recess of the distal portion when the cap is in the extended state.

2. The assembly of claim 1, wherein in the folded state, a distance between the distal surface of the endoscope and the proximal end of the distal portion is minimized and a curvature of the fold is maximized, and in the extended state, the distance is increased and the curvature of the fold is decreased, thereby increasing the field of view of the endoscope camera.

3. The assembly of claim 2, wherein a proximal end of the first region of the proximal portion has a size and shape that fits snugly outside the endoscope at a position proximal to the distal surface of the endoscope, a distal end of the first region at the fold extends distally relative to the distal surface of the endoscope, and the second region extends proximally from the first end at the fold to the second end at the junction.

4. In the folded state, the joint is adjacent to the distal surface of the endoscope. By the joint translating distally in the extended state, the distance is provided between the distal surface of the endoscope provided with the endoscope camera and the proximal end of the distal portion. The assembly according to claim 3.

5. The cap is biased in the extended state, and by operating a pull string extending through the working channel of the endoscope to pull the distal portion of the cap proximally, the distance between the distal surface of the endoscope and the proximal end of the distal portion is reduced. When the distance is reduced, the curvature of the folded portion is increased by the flexible material of the proximal portion and the angle of the first region with respect to the longitudinal axis of the endoscope is reduced. The assembly according to claim 2.

6. The cap is biased in the folded state, and by operating a flexible member extending through the working channel of the endoscope to push the distal portion of the cap distally, the distance between the distal surface of the endoscope and the proximal end of the distal portion is increased. When the distance is increased, the curvature of the folded portion is reduced by the flexible material of the proximal portion and the angle of the first region with respect to the longitudinal axis of the endoscope is increased. The assembly according to claim 2.

7. The cap further has a function of preventing the target tissue captured in the recess of the distal portion from extending proximally with respect to the proximal end of the distal portion. The function includes a partition fin, web, strand, or grid extending laterally at the proximal end of the distal portion. The function includes a transparent plate extending laterally at the proximal end of the distal portion. The transparent plate includes a hole for passage of the closing device. The assembly according to any one of claims 1 to 6.

8. The assembly according to any one of claims 1 to 7, wherein the actuating mechanism of the closing device and the extension mechanism of the cap are interlocked such that the actuating mechanism is triggered by extending the cap to deploy the closing device. **Claim 9** The assembly according to claim 8, wherein the extension mechanism comprises a flexible member that extends through the working channel of the endoscope and pushes the distal portion of the cap distally, and the closing device is deployed when the distal portion of the cap is pushed distally to a trigger point. **Claim 10** The assembly according to claim 8, wherein the extension mechanism comprises a pull string that extends through the working channel of the endoscope, and when the pull string is pulled as the cap extends, a force to deploy the closing device is applied by the pull string. **Claim 11** The assembly according to any one of claims 1 to 10, wherein the closing device comprises a clip device. **Claim 12** The assembly according to any one of claims 1 to 11, wherein the closing device comprises a ligation band device. **Claim 13** The assembly according to any one of claims 1 to 12, wherein the proximal portion includes two or more folding portions, the distance between the distal surface of the endoscope and the proximal end of the distal portion is minimized and the curvature of each folding portion is maximized in the folded state, and the distance is increased and the curvature of each folding portion is decreased in the extended state, thereby increasing the field of view of the endoscope camera. **Claim 14** The assembly according to any one of claims 1 to 13, wherein the first region forms a flare shape in the extended state. **Claim 15** The assembly according to any one of claims 1 to 14, wherein the first region forms a frustum of a cone shape in the extended state.

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