Patent ID: 12220144

It will be convenient to note that some parts in the figures have been drawn in transparency in order to uncover interior components.

DETAILED DESCRIPTION

Referring toFIG.1, a device10for pressure necrosis and tissue shearing according to one aspect comprises a first member11and a second member12connected to one another by a thread13. Each of the first member11and second member12can comprise a generally dome shaped housing110advantageously made of a biocompatible material. The housing110encapsulates a material111,121respectively. The materials111,121encapsulated within the respective members11,12show magnetic attraction to one another. Advantageously, both materials111and121can be permanent magnets. Alternatively, one material can be a permanent magnet, and the other one a material which is magnetically attracted to the permanent magnet, such as though not limited to a ferromagnetic material, e.g. an iron alloy. Each of the first member11and the second member comprises a generally planar surface of contact112,122respectively, advantageously forming a bottom of the housing110. The materials111and121advantageously have magnetic properties such that they show magnetic attraction when the first member and the second member are placed with their surface of contact112,122against each other, e.g. through suitable orientation of the magnetic poles N and S of the permanent magnets within the housing110. In use, therefore, the first and second members will be disposed in such a manner that the surfaces of contact112,122are in facing relationship. Each of the first and second member further comprises a point of attachment113at which the thread13is connected to the respective member. The thread connection at113is advantageously a fixed connection, e.g. the thread13is fixedly secured, such as through tying or potting to the member. Each member11,12may further comprise a suitable structure for facilitating handling of the member, e.g. an eye114, allowing an endoscopic tool for engaging the respective member.

As a surprising effect, the device10allows for creating an opening through a tissue wall separating two body cavities. The opening is larger than the size of any of the first member11and the second member12. To this end, the members11,12comprising the magnets111,121are used, in a first step, for compressing tissue between oppositely arranged magnetically attracting members thereby causing pressure necrosis. Subsequently, in a second step, the necrotic tissue collapses and forms an opening. The members11,12lack support by the tissue and will fall through the opening created by necrosis. The members11,12become suspended by thread13and will pull on the thread13due to gravity. The thread13, supported by the tissue, will start shearing the tissue to create a larger opening.

A first possible application is shown inFIGS.2A-Cand relates to treatment of diverticulum, such as though not limited to Zenker's diverticulum, which is a pouch21protruding from a lumen of the GI tract20. In the particular case of Zenker's diverticulum, the lumen20is the hypopharynx. Referring toFIG.2A, the device10is introduced into the lumen20and the first member11placed in the pouch21while the second member12placed in the lumen20at a corresponding location. The device10can be introduced by any suitable endoscopic means. Since the pouch21is open towards the lumen20, a delivery device, such as an endoscope with suitable system for engaging and positioning the members11,12, e.g. a grasper, forceps or specific catheter, can be guided to the pouch21to place the first member11. No tissue needs to be pierced in order to place member11. The same endoscope or another endoscope can be guided to the adjacent lumen20to place the second member12. It is alternatively possible to place the second member12first, and to place the first member11subsequently. The thread13is either connected to the two members11and12prior to loading the device10in the endoscope, or may be connected to either or both members upon placement. Advantageously, the thread13connecting the two members11and12does not pass through the tissue wall23, but forms a loop over the periphery24of the tissue wall. The placement of the members can be guided with endoscopic ultrasound and/or fluoroscopy which are procedures well-known to persons skilled in the art of endoscopic procedures.

Referring toFIG.2B, due to the magnetic attraction between the members11and12, the tissue wall23gets trapped between the two members and is compressed. By suitable selection of the magnetic attraction force between the magnets111and121, a compression pressure larger than 5 mm Hg can be created, which is sufficient for stopping blood supply to the trapped tissue and hence causing necrosis of the tissue within a few days. The necrotic tissue trapped between the members11and12collapses and frees the members11and12which remain attached to one another and suspended on the thread13. The first and second members and the thread now form a closed loop around the tissue wall23, enclosing that portion of tissue interposed between the periphery24and the freshly formed necrotic opening. Due to their weight, the members11and12now pull on the thread loop13in the direction of gravity. Referring toFIG.2C, the thread13is now supported by the periphery24of the tissue wall and the tension in the thread13caused by the weight of the members11and12will start shearing the tissue from the periphery24until the initial opening22formed by necrosis is reached. The action of the thread13shearing the tissue wall23is represented inFIGS.3A-Bfrom other viewing directions. By so doing, a lesion extending over the entire depth of the pouch21can be created without requiring recourse to larger structures and without requiring specific delivery devices.

The example described above is just one possibility of how device10can be used. Referring toFIG.4, with two such devices10and10′, with each one device placed in one of two adjacent cavities40,41, a lesion can be created extending over the distance by which the first member11and the second member12are spaced apart. The magnetically attracting members11and12′ of respective devices10,10′ are placed in correspondence, each in the respective cavity. Portions of the tissue walls42and43of each respective cavity40,41overlapping the members11and12′ are compressed. Likewise, the other members12and11′, which also magnetically attract each other, are placed in correspondence, each in the respective cavity at a location spaced apart from the members11and12′. Portions of the tissue walls42and43overlapping the members12and11′ are compressed. Members11and12are spaced apart from each other, such as by a distance of at least 40 mm, advantageously at least 50 mm to enable making a larger lesion. The tissue trapped between members11and12′ on the one hand and between members12and11′ on the other hand will become necrotic and collapse, which will free the members towards one cavity40or the other one41. Either thread13or13′ will be pulled by the freed member couples11-12′ and12-11′ in the direction of gravity, which will shear the tissue in between the openings formed. It will be convenient to note that also in the case ofFIG.4, no puncture or piercing through the tissue wall is required for initial placement of the devices10and10′, as long as both cavities40and41are accessible. A configuration as inFIG.4may be useful for creating gastrojejunal anastomosis or jejuno-jejunal anastomosis.

It will be convenient to note that devices and assemblies described herein advantageously allow to perform tissue shearing assisted by pressure necrosis and/or compression anastomosis.

Even though the devices10and10′ inFIG.4are shown to comprise two magnetic members11,12and11′,12′ each, it will be clear that device configurations comprising more than two members, such as three members or four members connected by a thread are similarly applicable. By way of example, device50shown inFIG.5comprises three members11,12and14connected by thread13. Two such devices50can be used in the same way as the example shown inFIG.4, each device being placed in a different one of the adjacent cavities40and41, as with the devices10and10′. The third member14may comprise its proper magnet141or magnetically active material.

The shape of the housing110of the members11,12and possibly14, and the shape of the magnets or magnetically active materials111,121as well as of the surface of contact112,122is not particularly limited. Suitable shapes and configurations may be chosen depending on any particular application. By way of example, instead of dome-shaped, such housing may be cylindrical, advantageously with planar top and bottom base. There is no preference for using the top or the bottom as surface of contact in the latter case.

Each member can comprise a suitable handling structure for manipulating the member. In a first example, referring toFIG.5, the members11,12and14can comprise one or more thread loops117which facilitate handling of the members by a forceps. The thread loops117project from the housing of the member and can be provided in addition or in alternative to other handling structures, such as the engagement eye. In another example, referring toFIGS.6A-D, the engagement eye or hole114, or the thread loop117as inFIG.5, can be replaced by, or be supplemented with an advantageously ribbed projecting wall115allowing engagement by a forceps, e.g. of the types commonly used in endoscopic procedures. The magnet, or magnetically active material is received in interior and completely closed recess116. Referring toFIGS.7A-10C, the engagement hole114may be oriented parallel to the surface of contact112, perpendicular thereto, or oblique.

Referring toFIGS.9A-9C, it may be useful to provide the hole114as a through-hole and the magnet111advantageously surrounding the through-hole114. The through-hole is advantageously arranged to traverse the surface of contact112of the member. One advantage of such an arrangement is shown inFIG.25.FIG.25differs with respect toFIG.4only in the shape of the second members12,12′ which comprise such a through-hole114and in which the magnets are advantageously annular surrounding the through-hole114. Referring toFIG.25, the through-hole114allows to pass a medical tool, such as a needle, through the respective member12,12′. Since the magnets of members12and12′ surround the through-hole114, a necrotic tissue, which may be anastomosed, is created surrounding the location of the through-hole114, allowing a needle or other tool to pass through the tissues42and43safely.

Referring toFIGS.11A-17B, the surface of contact112,122which defines the contact being made between the member and the tissue, can be, but need not be, planar. Other kinds of shapes, such as concave, convex, stepped or staircase-like can be contemplated. It will be convenient to note that the surface of contact of members placed at opposite sides of the tissue wall, such as members11and12inFIG.2, and members11and11′ inFIG.4, may have a complementary shape. By way of example, the shapes shown inFIGS.13A-13B,15A-15B and17A-17Bmay be complementary. In another example, two mushroom-shaped members as shown inFIGS.17A-17Bmay be used. These mushroom-shaped members may form plugs or anchors preventing the magnetically attached members to fall through the tissues once the tissue becomes necrotic and collapses.

Referring toFIGS.7A-10CandFIGS.18A-20C, the magnets111,121or, as the case may be, magnetically active materials can have any suitable shape. They may be monolithic within the housing110, or made up of separate parts arranged adjacent one another, as shown inFIGS.19A-20C. Other shapes than disc or cylindrical are possible, such as ring, oval or parallelepiped.

It will be convenient to note that the shearing by the thread13can be facilitated by suitable selection of the mass (weight) of any of the members11and12. Generally, a tension on the thread of at least 5 mm Hg may be sufficient for causing tissue shearing, with tensions of at least 10 mm Hg, at least 20 mm Hg, at least 50 mm Hg, or at least 100 mm Hg being advantageous. In some instances, it may be useful to maintain the thread13under a constant tension, as from the onset, particularly even prior to the collapse of the tissue due to pressure necrosis performed by the members11and12. One possible way of accomplishing is by making one of the members slidable relative to the thread. Referring toFIG.21, device60differs from device10in that the second member62is not fixedly attached to the thread13, but is allowed to slide along the thread. The first member11is attached to one end of the thread13, and a mass member63is attached to the opposite end of thread13, with the second member62being slidingly attached to thread13in between the first member11and the mass member63. To this end, the second member62comprises a through hole621slidingly receiving thread13. Mass member63has a suitable weight in order to provide a desired tension in thread13, but will advantageously not be magnetically attracted to either one of the members62and11. In particular, mass member63may not comprise any magnet or magnetically active material. Mass member may have a mass at least equal to 50%, 75% or 100% of the mass of any one of the members11and12. When members11and62are placed as shown inFIG.2, the mass member63is freely suspended and will pull on the thread13and put it under tension to immediately start shearing tissue. It will therefore be clear that device60allows for simultaneous pressure necrosis and tissue shearing. A yet alternative embodiment is obtained by adapting the arrangement10ofFIG.1to include the mass member63interposed between the first member11and the second member12. In this case, mass member63may, but need not be slidingly attached to the thread13.

FIGS.22A-Bshow alternative embodiments to the device60, in which tension in the thread13is created through a thread winding system integrated within one of the members, or both. Referring toFIG.22A, device70differs from device10in that the second member72comprises a thread winding system74for loading thread13in order to maintain tension in the thread. Thread winding system74can comprise a spiral spring741which is preloaded to pull on thread13according to a desired preload force acting in the direction of the arrow. Magnets71may be placed peripherally to thread winding system74, as shown inFIG.22A, or in any other suitable configuration. Referring toFIG.22B, an alternative toFIG.22Ais shown, which differs from device70in that the thread winding system75in the second member73is a spiral spring which is coiled around magnet76, i.e., spring73and magnet76are concentric. In an alternative embodiment, the arrangement ofFIG.21is adapted to incorporate the thread winding system in the mass member63.

Yet an alternative embodiment to the devices70ofFIGS.22A-Bis shown inFIGS.23A-C, representing a device80comprising a thread winding system84incorporated in the second member82. Device80differs from device70in the disposition of magnet81(seeFIG.23B) which is annular and arranged above or below the thread winding system84. Alternatively, possibly annular magnets may be arranged above and below the thread winding system, e.g. in a symmetrical fashion. The thread winding system84comprises a spiral spring operably connected to a pulley86. Thread13is wound on pulley86. Spiral spring85, or any other suitable spring, is advantageously preloaded to apply a suitable torque on pulley86to pull on thread13. In the latter design, the thread winding system84and the magnet81can be kept separated from one another without interference.

Referring toFIG.23C; a blocking system89can be provided in the second member82for blocking rotation of the thread winding system84. By way of example, blocking system89comprises a blocking member88which blocks the pulley86and/or the spiral spring85, e.g. by engagement. The blocking system89is releasable, e.g. by pulling on thread87attached to blocking member88, the blocking member88is released and the pulley and spiral spring can turn and wind the thread13.

Referring toFIG.13, a yet alternative embodiment is shown, which differs from device10in that a plurality of third members91are attached along the thread13, between the first member11and the second member12. The third members may be arranged with advantageously uniform spacing between one another and they are advantageously fixed to thread13. The third members advantageously show magnetic attraction to the first member11and/or the second member12and act here as thread pulling means. As the tissue is further sheared, the third member91closest to the first member11will progressively move to the first member due to the magnetic attraction. The third members91can have any suitable shape, e.g. beads, and advantageously have dimensions substantially smaller than those of the first member and second member, e.g. half or less of the size of the first member and/or second member. It will be convenient to note that neither the thread winding system inFIGS.22A-Band23A-C, nor the third members inFIG.13prejudice the position and shape of the magnet or magnetically active material, of the housing, or of the surface of contact, and these features may assume any suitable shape, e.g. as illustrated inFIGS.7A-10C through18A-20C.

Yet another alternative to the systems shown inFIG.21through24is to use an elastic or resilient thread to couple the members to one another. This thread is advantageously preloaded prior to placement of the device, e.g. by providing an appropriate structure which maintains the members at a distance larger than the length of the thread at rest, which structure is removed upon installing the device. The thread is stretched and thereby preloaded. In one example, the thread may be made of, or comprise a shape memory material. Suitable shape memory materials are shape memory polymers or (metal) alloys, which e.g. can retract at a body temperature level. One example is DiAPLEX® commercialised by Mitsubishi Corporation Fashion Co., Ltd., Japan. The use of a mass member pulling on the thread, of a traction system, or of elastic or resilient thread can be advantageously used in the application referred to inFIG.4. That is, either one or both the devices10and10′ inFIG.4may be provided with means for (pre)loading the thread13,13′. In the example ofFIG.4, (pre)loading the threads13,13′ with tensile stress enhances fusion between the tissues42and43.

The thread is advantageously made of a non-resorbable material, and is advantageously a monofilament thread, e.g. made of polyamide. The shape of the housing110is advantageously atraumatic. While in the above embodiments, only one thread is described extending between the first member and the second member, it will be convenient to note that a plurality of such threads, e.g. two, three or more can be provided to extend between, and be connected to the first member and second member. The means for pulling the thread may be operable to pull some or all of these threads. Multiple threads advantageously allow for shearing tissue across multiple, spaced apart sections.

Each of the members has a diameter D (seeFIG.6B) or largest size advantageously smaller than or equal to 40 mm, advantageously smaller than or equal to 30 mm, advantageously smaller than or equal to 20 mm, advantageously smaller than or equal to 15 mm, advantageously smaller than or equal to 20 mm. The member11or12can have a diameter or size of at least 5 mm, advantageously at least 10 mm. The thread13extending between the members has a length which in an initial placement position is advantageously at least 80 mm, advantageously at least 100 mm, advantageously at least 120 mm. The mass of the member11or12generally depends on the application, and may be determined on the basis of e.g. contact length of the thread with the tissue in order to arrive at a desired tension on the thread.

Some aspects of the present invention as described herein are set out in the following numbered clauses.

A. Method of creating pressure necrosis of a tissue wall between a pouch and an adjacent cavity in a human or animal body, wherein the tissue wall comprises a periphery forming an edge of an opening between the pouch and the cavity, the method comprising:placing a first member into the pouch, such that the first member is adjacent the wall,placing a second member in the cavity and proximate the first member,wherein the first member and the second member comprise materials which magnetically attract one another,wherein the first member and the second member are placed such that there is magnetic attraction between the first member and the second member through the wall and wherein the first member and the second member compress an overlapping portion of the wall to create pressure necrosis,wherein the first member and the second member are connected through a thread, wherein the thread extends over the edge.

B. Method of clause A, wherein, following pressure necrosis, the first member and the second member are suspended by the thread forming a loop over the wall.

C. Method of clause B, wherein the thread shears the wall by action of a weight of the first and second members.

D. Method of clause B, wherein the thread shears the wall while the thread is under tension by action of a mechanism that induces a traction force in the thread.

E. Method of clause B, comprising exerting a pulling force on the thread while the thread shears the wall.

F. Method of clause B, wherein the wall is cut by the thread in a direction of gravity.

G. Method of clause A, wherein the thread does not pierce through the wall until pressure necrosis is created.

H. Method of clause A, wherein at least one of the first member and the second member comprises an encapsulated magnet.

I. Method of clause A, comprising inserting a delivery device having an internal lumen into the cavity, andguiding the delivery device through the opening to the pouch and delivering the first member to the pouch by sliding the first member through the internal lumen;delivering the second member to the cavity by sliding the second member through the internal lumen;wherein the first member and the second member are connected by the thread in the internal lumen.

J. Method of clause A for treating diverticulum, wherein the pouch is a diverticulum.

K. Method of clause J, wherein the cavity is a segment of a gastrointestinal tract of the human or animal body.

L. Method of creating compression anastomosis between adjacent tissues, each of the tissues forming a wall of one of adjacent cavities of a human or animal body, the method comprising:placing a first member and a second member in a first one of the adjacent cavities, proximate a first one of the walls, wherein the first member and the second member are spaced apart and connected to a first thread;placing a third member and a fourth member in a second one of the adjacent cavities and proximate a second one of the walls, wherein the third member and the fourth member are connected to a second thread and are placed in correspondence of a respective one of the first member and the second member;wherein the first, second, third and fourth members comprise materials which magnetically attract one another through the adjacent tissues to create pressure necrosis of an overlapping portion of the wall.

M. Method of clause L, wherein the first thread does not extend to the second one of the adjacent cavities upon placement of the first and second members and wherein the second thread does not extend to the first one of the adjacent cavities upon placement of the third and fourth members.

N. Method of clause L, comprising a step of shearing the adjacent tissues by the first thread or the second thread, wherein the shearing opens a lesion extending between a necrotic opening through the adjacent tissues formed at a location of the first member and a necrotic opening through the adjacent tissues formed at a location of the second member.

O. Method of clause N, wherein one of the first thread and the second thread shears the adjacent tissues while the respective thread is under tension by action of a mechanism that induces a traction force in the respective thread.