WO2009040834A1

WO2009040834A1 - Improved fragmentable device for the anastomosis of hollow organs

Info

Publication number: WO2009040834A1
Application number: PCT/IT2007/000662
Authority: WO
Inventors: Carlo Rebuffat
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-09-25
Filing date: 2007-09-25
Publication date: 2009-04-02
Anticipated expiration: 2010-03-25

Abstract

A fragmentable device for the anastomosis of hollow organs comprises a bowl- shaped outer body (1), a ring-shaped intermediate body (2) suitable to be inserted into the cavity (1 a) defined by said bowl-shaped outer body (1) and a ring-shaped inner body. (3) suitable to be pressure-inserted into said intermediate body (2). The outer body (1), intermediate body (2) and inner body (3) are formed each by a plurality of separable sectors and the intermediate body (2) is provided with a plurality of tongues (4b) suitable to press the edges of the hollow organs against the peripheral wall of the cavity (Ia) of the outer body (1). The external diameter of the intermediate body (2) at the free ends (4c) of the tongues (4b) is substantially equal to or slightly lower than the diameter of the cavity (Ia) of the outer body (1), and the free ends (4c) are made of a biodegradable and absorbable material.

Description

IMPROVED FRAGMENTABLE DEVICE FOR THE ANASTOMOSIS OF HOLLOW ORGANS

The present invention relates to an improved fragmentable device for the anastomosis of hollow organs of the human body, such as parts of the digestive tract, the intestine or the ano-rectal cavity.

Fragmentable devices for anastomosis are generally made up of an assembly of cylindrical bodies which can be introduced into each other that are used to press the terminal edges of the organs to be anastomized thus forming a constriction such that they necrotize. During the intervention, the surgeon performs a purse-string suture between the organs to be anastomized, then pulls the edges of the organs inside the fragmentable anastomosis device and introduces and locks the cylindrical bodies into each other. The pressure exerted by the tissues pressed inside the device keeps tightly compact and stable the fragmentable bodies which will fragment into sectors when the necrosis has occurred due to the consequent lack of pressure by the tissues thereon and are expelled through natural paths.

US patent n⁰ 5,290,298 discloses a fragmentable anastomosis device comprising three cylindrical bodies which can be inserted into each other. The first cylindrical body, the outer one, is bowl-shaped and formed of two parts also bowl-shaped introduced one into the other, whereas the second and third bodies, i.e. the intermediate and inner one, have an annular shape and are formed of a plurality of sectors arranged side by side in the circumferential direction. The device is introduced in the anastomosis site by means of a specific tool and the edges of the hollow organs to be anastomized are introduced into the cavity defined by the outer bowl-shaped body. Subsequently, the intermediate body and the inner body are introduced in the cavity of the outer body. As the radial play between the cavity and the intermediate body is lower than the thickness of the tissues of the organs to be anastomized, the edges of the hollow organs are pressed and constricted between the outer body and the intermediate body and necrotize over a short time. Upon completion of the assembly of the device, the introducing tool cuts the outer bowl-shaped body at the bottom, dividing its two parts into sectors to facilitate the expulsion through natural paths. The sectors maintain their assembly position thanks to a series of radial protrusions and recesses formed in the peripheral walls of the two parts and which engage one into the other.

An improvement on the fragmentable device of the above-mentioned patent is disclosed in patent application WO 2007/057933. The device bodies are all formed by sectors arranged side by side in the circumferential direction so as to dispense with the final step of cutting the outer bowl-shaped body. Moreover, the size of the device in the axial direction is significantly reduced and all the edges have been properly radiused to minimize the discomfort of the patient in the period when the device is inside the hollow organs, and in particular the tenesmus feeling when the device is applied in the ano-rectal cavity.

The main drawback of known fragmentable anastomosis devices is that they do not achieve a positive outcome of the intervention if the purse-string suture is not performed completely, i.e. along 360° of the connecting region between the hollow organs. In fact, after assembling the device, the sectors of the cylindrical bodies remain together only thanks to the radial pressure exerted by the edges of the hollow organs introduced therebetween. Therefore, one or more flaws in the suture preventing the pull of a part of said edges within the device will cause a discontinuity in pressure resulting in the immediate fragmentation of the device and thus in the total failure of the surgical intervention. Furthermore, even when the purse-string suture is correctly performed, the necrosis of the tissues may occur in a non-uniform way over time, i.e. some areas may reach the necrosis prior to other areas, causing a premature and undesirable fragmentation of the device.

Hence, the purpose of the present invention is to provide an improved fragmentable device for the anastomosis of hollow organs free from said drawbacks. Such a purpose is achieved with an improved fragmentable device, whose main characteristics are specified in the first claim and further characteristics are specified in the subsequent claims.

The fragmentable anastomosis device according to the present invention includes three cylindrical bodies which can be inserted into each other, an outer bowl-shaped body, an intermediate body and inner body both having an annular shape. The portion of the intermediate body that presses the edges of the hollow organs inside the cavity of the outer body has an external diameter substantially equal to or slightly lower than the cavity diameter and is made of an absorbable and biodegradable material.

The main advantage of the fragmentable device according to the present invention is that the particular choice of the diameter of the intermediate body relative to the diameter of the cavity allows to keep the sectors of the bowl-shaped body together regardless of the presence of tissues, thus assuring the success of the anastomosis even with purse-string sutures not perfectly performed along 360° of the connecting region between the hollow organs. Furthermore, thanks to the use of a biodegradable and absorbable material, the fragmentation of the device bodies occurs according to the preset time required for the reabsorption of the material and not to the time required for the necrosis of the tissues, which can only be approximately estimated, thus always assuring to achieve the complete necrosis of the tissues and therefore the full success of the anastomosis intervention.

Further advantages and characteristics of the improved fragmentable device according to the present invention will be evident to those skilled in the art from the following detailed and non-limiting description of an embodiment thereof with reference to the annexed drawings wherein: Figures 1 and 2 show perspective exploded views of the fragmentable device according to the present invention;

Figure 3 shows a front view of the device of Figs. 1 and 2 completely assembled;

Figure 4 is a cross-sectional view along line IV-IV of Fig. 3;

Figures 5 and 6 show perspective views of a sector of the intermediate body of the fragmentable device of Fig.1 ;

Figure 7 shows a front and a side view of the intermediate body of Figs. 5 and 6;

Figure 8 shows a top plan view of the fragmentable device according to the present invention; and

Figure 9 is a longitudinal sectional view along line IX-IX of Fig.8. Referring to figures 1 to 7, the fragmentable device according to the present invention conventionally includes a bowl-shaped outer body 1, a ring-shaped intermediate body 2 suitable to be inserted into the cavity Ia defined by the bowl- shaped outer body 1, and a ring-shaped inner body 3 suitable to be pressure-inserted into the intermediate body 2.

The outer body 1, the intermediate body 2 and the inner body 3 are formed each by a plurality of separable sectors.

In particular, in the illustrated embodiment, the outer body 1 is made up of an outer part Ib and an inner part Ic inserted one into the other and having a bowl-shape. Each part Ib, Ic has slots in the radial direction that define a plurality of identical sectors. Moreover, parts Ib, Ic each have a series of apertures in the bottom that define cut lines suitable to allow the cut of the bottom of the outer body 1 upon completion of the assembly of the fragmentable device.

As shown in figure 4, once cut into sectors, the two parts Ib, Ic, the outer and the inner one, maintain their assembly position thanks to a series of radial protrusions Id formed on the outer peripheral wall of the inner part Ic, each engaging recesses Ie formed in the inner peripheral wall of the outer part Ib. Conventionally, such protrusions and recesses have a dove-tail cross-section, which is suitable to create an undercut in the radial direction that keeps the sectors of parts Ib, Ic together.

The intermediate body 2 consists of a plurality of sectors 4 arranged side by side in the circumferential direction, each of which is provided with a top arcuate profile 4a from which a plurality of tongues 4b extend axially which are suitable to press the edges of the hollow organs inserted in the device against the peripheral wall of cavity Ia of the outer body 1.

The inner body 3 consists of a plurality of sectors 5 arranged side by side in the circumferential direction, each of which is provided at the base and at the top with radial projections suitable to allow the abutment and snap-locking of inner body 3 onto the intermediate body 2.

With reference to figures 8 and 9, according to the novel aspect of the present invention the external diameter of the intermediate body 2 at the free ends 4c of tongues

4b is substantially equal to or slightly lower than the diameter of cavity Ia of the outer body 1. Therefore, upon insertion of the intermediate body 2 into cavity Ia of the outer body 1, the free ends 4c will define a small radial play with the peripheral wall of cavity Ia or will substantially be in contact with it thus minimizing or preventing any relative movement in the circumferential direction between the sectors of parts Ib, Ic of the outer body 1. Thanks to this expedient, the fragmentable device will remain compact even in the absence of tissues between the outer body 1 and the intermediate body 2, thus assuring the success of the anastomosis even with purse-string sutures not perfectly performed along 360° of the connecting region between the hollow organs.

The maximum radial play between the intermediate body 2 at the free ends 4c and the diameter of the cavity Ia must never allow the sectors of parts Ib, Ic of the outer body 1 to move in the circumferential direction such to cause the disengagement of the dove-tail protrusions Id from the respective recesses Ie. According to numerous experimental tests carried out by the inventor, it comes out that in order to obtain a radial play meeting the above-mentioned requirement, the ratio between the external diameter of the intermediate body 2 at the free ends 4c and the diameter of cavity Ia must range from 0,9 to 1. Moreover, the free ends 4c of tongues 4b are made of a biodegradable and absorbable material. Once the edges of the hollow organs are enclosed between the outer body 1 and the intermediate body 2, the free ends 4c of tongues 4b will start to degrade getting progressively thinner up to complete reabsorption. Consequently, the radial play between the intermediate body 2 and the cavity Ia of the outer body 1 will increase enabling a relative movement between the sectors of parts Ib, Ic of the outer body 1 in the circumferential direction up to determining the disengagement of the protrusions Id from the recesses Ie, thus resulting in the fragmentation into sectors of the outer body 1 and therefore also of the intermediate body 2 and the inner body 3 and in their disposal through natural paths. The free ends 4c of biodegradable and absorbable material can be injection co- moulded onto the respective tongues 4b of the intermediate body 2. Alternatively, the free ends 4c can be made as separate components and mechanically fixed to the tongues 4b of the intermediate body 2.

Thanks to the wide range of biodegradable and absorbable materials available on the market it is possible to design a device that is "bio-fragmentable" after a preset time. In particular, the reabsorption time is equal to at least 1,5 times the time estimated for the necrosis of the edges of the hollow organs inserted into the device, such that it is possible to guarantee the complete healing of the anastomized region.

Examples of biodegradable and absorbable materials that can be used in the present invention are polyglycolic acid, polydioxanone, lactic acid, caprolactone and glycolide-lactide copolymers, that have preset degradation and reabsorption times ranging from 5 to 90 days.

The free ends 4c of tongues 4b may have a surface texture suitable to increase the grip on the edges of the hollow organs inserted between the outer body 1 and the intermediate body 2. Said texture may be for example a knurling, which also has the effect of increasing the surface area of the free ends 4c thus favouring the degradation and reabsorption process.

Possible variations and/or additions may be made by those skilled in the art to the above-described and illustrated embodiment while remaining within the scope of the subsequent claims.

Claims

1. Fragmentable device for the anastomosis of hollow organs comprising a bowl- shaped outer body (1), a ring-shaped intermediate body (2) suitable to be inserted into the cavity (Ia) defined by said bowl-shaped outer body (1) and a ring-shaped inner body (3) suitable to be pressure-inserted into said intermediate body (2), said outer body (1), intermediate body (2) and inner body (3) being formed each by a plurality of separable sectors and the intermediate body (2) being provided with a plurality of tongues (4b) suitable to press the edges of said hollow organs against the peripheral wall of the cavity (Ia) of said outer body (1), characterized in that the free ends (4c) of the tongues (4b) are made of a biodegradable and absorbable material, the external diameter of the intermediate body (2) at said free ends (4c) being lower than or equal to the diameter of said cavity (Ia).

2. Fragmentable device according to the preceding claim, characterized in that the ratio between the external diameter of the intermediate body (2) at the free ends (4c) of the tongues (4b) and the diameter of the cavity (Ia) of the outer body (1) ranges from 0,9 to 1.

3. Fragmentable device according to one of the preceding claims, characterized in that said free ends (4c) are injection co-moulded onto the tongues (4b) of the intermediate body (2).

4. Fragmentable device according to claim 1 or 2, characterized in that the free ends (4c) of the tongues (4b) are separate components mechanically fixed to the tongues (4b) of the intermediate body (2).

5. Fragmentable device according to one of the preceding claims, characterized in that the biodegradable and absorbable material has a reabsorption time equal to at least 1,5 times the time estimated for the necrosis of the edges of the hollow organs inserted into the device.

6. Fragmentable device according to the preceding claim, characterized in that said reabsorption time ranges from 5 to 90 days.

7. Fragmentable device according to one of the preceding claims, characterized in that the biodegradable and absorbable material is selected among polyglycolic acid, polydioxanone, lactic acid, caprolactone and glycolide-lactide copolymers.

8. Fragmentable device according to one of the preceding claims, characterized in that the free ends (4c) of the tongues (4b) have a surface texture suitable to increase the grip on the edges of the hollow organs inserted between the outer body (1) and the intermediate body (2).

9. Fragmentable device according to the preceding claim, characterized in that said surface texture is a knurling.