DEVICE FOR CONNECTING A PATCH WITH A BODY CHANNEL
DESCRIPTION
This invention relates to a device for connecting at least one patch with a vessel for the conveyance of organic fluids, for example a blood vessel, lymphatic vessel or similar.
In order to simplify the disclosure of this invention, reference will be made in the description only to devices for connecting patches to blood vessels, not in a limiting way.
It is known that aneurysms can form due to pathologies of the vascular system such as stenosis or atheromas . Aneurysms, or saccular swellings caused by abnormal dilation of the walls of a blood vessel, may even lead to the rupture of the vessel causing a haemorrhage, which may even be fatal.
At present, in patients with such pathologies, endoluminal intervention is becoming standard practice, the stenosis or the atheroma is removed using a probe and a vascular prosthesis is used to reconstruct the physiological tubular form of the vessel.
Where an endoluminal operation cannot be carried out it is necessary to perform open surgery. In other words, it is necessary to incise the patient's tissues in order to access the section of vessel to be operated on directly. For example, with a surgical operation it is possible to clear the vessel from the stenosis or the atheroma after making a longitudinal incision. In the more serious pathologies it may even be necessary to remove a portion of the wall of the vessel . Once the vessel has been cleared it is necessary to close the incision in the wall of the vessel applying a patch of tissue-like structure to the edges by suturing.
Alternatively to the operations described above it is possible to apply a ramification to the vessel, known as by-pass, consisting in a vascular prosthesis of natural or biocompatible material. In this case, too, it is necessary to suture the ends of the prosthesis to incisions in the walls of the patient's own vessels.
In cases where it is necessary to remove a section of the vessel, a vascular prosthesis or a tubular patch, equal in length to the section of diseased vessel removed, is sutured head-to-head to the end openings of the patient's recised vessel.
The main difficulty with the above mentioned interventions is determined by the fact that the patch
and the vascular prosthesis are currently connected to the vessel by suturing. This is a very invasive procedure for the patient, both due to the considerable length of time necessary for suturing the patch to the edges of the vessel, and due to the limited space in which the suture has to be made. These difficulties may cause corrugation or wrinkling of the wall of the vessel, even to the extent where an undesirable narrowing of the vessel's cross section occurs, with serious pathological consequences quoad valetudinem et vitam.
The aim of this invention is to create a device for connecting at least one patch to a vessel for the conveyance of organic fluids, as described above, which has the structural and functional characteristics needed to overcome the difficulties encountered in the prior art .
This aim is achieved by a device for connecting at least one patch to a lumen in a vessel for the conveyance of organic fluids, including grips associated with said at least one patch for its connection to the edges of said lumen.
In order to better understand the invention, an illustrative embodiment, not to be considered limiting, is illustrated in the enclosed drawings, in which:
Figure 1 shows a perspective view, partially in section, of the device according to the invention;
Figures 2 and 3 show a perspective view of two details of the device in Figure 1 ;
Figure 4 shows a perspective view, partially in section, of another detail of the device shown in Figure
1;
Figure 5a shows a sectioned perspective view of a group of details of the device shown in Figures 2, 3 and 4;
Figure 5b shows a perspective view, partially in section, of the detail shown in Figure 5a in another arrangement;
Figure 6 shows a first stage in the connection of the device in Figure 1 ;
Figure 7 shows the stage of insertion of the device in Figure 1 in a lumen in a vessel;
Figure 8 is a perspective view, marked by arrow VIII, of the device in Figure 1;
Figure 9 shows a perspective view, partially in section, of a detail of a different version of the device according to a further embodiment of the invention;
Figures 10 and 11 show a perspective view, partially in section, of the device in Figure 9;
Figure 12 shows a lateral section of a device according to a different embodiment of the invention;
Figure 13 shows, in lateral partial section, a stage of the connection of the device in Figure 12 ;
Figures 14, 15 and 16 show a perspective view of further embodiments of a detail of the device forming the subject of the invention;
Figure 17 shows a stage of the application of a device fitted with the detail in Figure 15;
Figure 18 shows a perspective view, partially in section, of another embodiment of the device;
Figure 19 shows a perspective view, partially in section, of a device according to yet another embodiment of the invention and
Figure 20 shows a perspective view, partially in section, of an embodiment of the invention.
With reference to the above Figures, it is possible to see a vessel 26 for the conveyance of organic fluids, for example a blood vessel 26 and in particular an artery. The vessel 26 has a wall 24 defined by an external surface 40 and an internal surface 42. There is a lumen or opening 22 in the wall 24 of the vessel, surrounded by an edge 34.
Reference 20 indicates, as a whole, an anastomotic device, or a device for connection of a natural or
synthetic patch 30 to the lumen 22 in the vessel 26. The term connecting device 20 is used to identify in particular a prosthesis for the connection, restoration or repair of vessels. The connecting device 20 includes grips, indicated as a whole by 28, associated with the said patch 30.
The grips 28 include a number of clips 32. Each clip 32 is a biocompatible structure and has arms 36, 38 placed radially around the edge 34 of vessel 26 surrounding lumen 22. Biocompatible structure means, for example, a thread or plate of stainless steel (for example AISI 316) for biomedical use, or gold, platinum, titanium, polymer-based synthetic or similar biologically inert material. In particular, the clip 32 has a first arm 36 and a second arm 38 which, when the clip 32 is closed, press, or grip, the external surface 40 and, respectively, the internal surface 42 of the wall 24 of the vessel 26. The first and the second arms 36 and 38 are held elastically in the closed position by the clip 32. For example, the arms 36 and 38 are linked at a central section 44. The clip 32 therefore takes the shape of a letter C. In particular, the central section 44 is placed transverse to the arms 36, 38, when they are in the closed position, and links to said arms 36, 38 by means of curled sections 46 or curls 46 delimiting
openings 47. The free ends 48 of the arms 36, 38 are bent towards each other inside the clip 32. For example, the said ends 48 are bent as a hook turned towards the surfaces 40,42. The dimensions of the clip 32 vary according to the diameter of the vessel 26 and the lumen 22. In particular, the arms 36, 38 of the clip 32 are of sufficient size to guarantee connection to the edge 34 of the lumen 22 in the vessel 26 equal at least to the extension of a stitch. Connection to the edge 34 means, more precisely, a connection to the wall 24 of the vessel 26 in proximity to the edge 34 of the lumen 22. For example, the arms 36, 38 are between 1 mm and 40 mm in length, in particular between 2 mm and 15 mm and the structure of the clip 32 has cross sections of dimensions between 0.038 mm and 1.5 mm, in particular between 0.05 mm and 0.8 mm.
At least one arm 38 has a seat 50 designed to receive removable devices for holding the clip 32 in the open position, as will be described in greater detail below. The second arm 38, or arm 38 inside the vessel 26, has an arcuate section 52 placed on the outside of the clip 32, close to the hooked end 48, forming a dip which is the said seat 50 designed to receive the removable holding means (Figure 2) . These removable holding means are fitted with an element of control for
their removal, which will be described in greater detail below. A thread ring 54 of biocompatible material is fitted into the opening 47 formed by the curls 46 of the number of clips 32 (Figure 3) . The thread ring 54 which links the curls 46 of the clips 32 follows the profile of the edges 34 of the lumen 22. Therefore, where the lumen 22 is made in the vessel 26 by a longitudinal incision, one of the transverse dimensions (DI) of the connecting device 20 will be greater than the other dimension (D2) (Figure 18) .
The patch 30 comprises biocompatible material shaped according to the operation to be carried out on the patient. For example, the patch 30 is shaped or cut in a sheet, in order to make a lateral connection to the vessel aimed at linking a by-pass created using a vascular prosthesis 56, or by-pass connection (Figures 1, 4, 5, 6, 7, 8, 17). The patch 30 is also shaped in such a way as to form a patch-stop for a lumen in the wall of a vessel (Figures 9, 10, 11, 18, 19 and 20) , or so as to create a tubular head-to-head stretch connecting two vessels, or a end-to-end connection (Figures 12 and 13) . The patch 30 is of biocompatible material, for example of the type known as DACRON™ or other polyester materials, including the type known as TEFLON™ (polytetrafluoroetylene) or in TEFLON™ coated
with DACRON™, or porous polyurethane. This material is knitted or woven to form the patch 30.
In particular, in the case of a lateral connection to the vessel 26 (by-pass) of a vascular prosthesis 56 known per se, the patch 30 includes at least one ring patch 58 associated with grips 28 (Figure 1) . For example, the ring patch 58 is associated with the second arm 38 of the clip 32, so as to result facing the internal surface 42 of vessel 26, when the device 20 is applied to it. A tubular patch 62 is linked to the internal edge 60 of the ring patch 58. Said tubular patch 62 has a first stretch 64 transverse to the ring patch 58 and a second stretch 66 inclined according to the direction 67 previously established as the branching or attachment direction of the vascular prosthesis 56. A second ring patch 70 is positioned facing the first ring patch 58 (Figure 4) is connected to the upper edge 68 of the first stretch 64. Said first ring patch 58, second ring patch 70 and said first tubular patch 64 are associated with gripping means 28, so as to hold them externally. The second tubular stretch 66 is whereas associated with elastic means 72 for connection by pressure (Figure 5) . For example, said elastic means 72 include at least one elastic ring with a biocompatible structure, for example a thread or a sheet of metal or
synthetic biocompatible material . Said biocompatible structure has a serpentine shape which extends circumferentially.
The various parts of the gripping means 28 and the elastic means 72 are fixed to the patch 30 so as to form a self-supporting structure. It is evident that said self-supporting structure forms a prosthesis for the connection of two vessels or of two sections of vessel . For example, the arms 36, 38 of the clips 32, the central section 44 of the clip 32 and the branches of the serpentine of the elastic means 72 are connected to the patch 30 by means of a series of stitches 75 in suture thread. The stitches 75 in suture thread, or sutures 75, are distributed uniformly along the metallic thread of the gripping means 28 and the elastic means 72.
It is possible to associate circular or elliptical patches 76 with the gripping means 28, and in particular patches in any other shape suitable for patching the lumen 22 in the wall 24 of the vessel 22, or a patch- stop (Figures 9, 10 and 11) . For example, a circular patch 76 is associated by stitches 75 to the arm 38 to be connected internally to the vessel 26, so as to rebuild the internal wall 42 of the vessel 26 once the device 20 for connection to the lumen 22 is applied.
In another embodiment, circular patches 76 are attached by stitches 75 to both the internal arm 38 and the external arm 36 of the gripping means 28, or only to the external arm 36 so as to be visible at the external surface 40 of the wall 24 of the vessel 26, once the device 20 for connection to the lumen 22 is applied. Alternatively, the edge of the circular patch 76 is associated by stitches 75 to the central section 44 of the number of clips 32.
In the case of a device 20 for connecting a patch, consisting of a tubular patch 78, to lumina 22 at the ends 80 of vessels 26, or a end-to-end connection, the gripping means 28 are associated, as described above, by means of their arm 36 external to the internal wall 82 of the free ends 84 of said patch 78 (Figure 12) .
The way the device 20 for connecting at least one patch 30 to a lumen 22 in a vessel for the conveyance of organic fluids works is described below.
The connecting device 20 is previously prepared for the application and sealed in a sterile container, in the manner described below. In a sterile laboratory, the number of clips 32 is positioned around a circumference, the arms 36, 38 are positioned radially. For example, the clips 32 are arranged equidistant from each other, with the opening of the C oriented for correct
gripping of the edge 34 of the lumen. The positioning of the clips 32 is made easier by threading the thread rings 54, of dimensions equivalent to the perimeter of the lumen 22 to which the device 20 is to be connected, in the openings 47 of the curls 46 (Figure 3) . Once the gripping means 28 have been constructed, according to the type of operation to be carried out, the relative patch 30 will be realized. For example, if it is necessary to create a by-pass, the ring patches 58, 70 and the tubular patches 64, 66 are linked together (Figure 4) . The patch 30 is then associated by stitches 75 to the gripping means 28 and, in this case, to the elastic means 72, creating the self-supporting structure of the connecting device 20 (Figure 5a) . Following the construction of the device 20, the arms 38 of the clips 32, which must be introduced into the lumen 22 made in the wall 24 of the vessel 26, are bundled and tied together using a suture thread 86, lodged in the prepared seat 50 to prevent the device 20 opening prematurely. The thread 86 is wound on and then held in position by a quick release knot with a quick release 88. With the device 20 in this position, the ring patch 58 which circles the bundled arms 38 is placed inside the arms 38 forming lobes 90. In other words the patch 30 in this position resembles a closed umbrella (Figure
5b) .
The tubular patch 66 associated with the elastic means 72, to be applied by pressure inside the end of the vascular prosthesis 56, is previously closed towards its axis exercising a radial pressure on the serpentine rings of the elastic means 72. When the elastic means 72 are closed, the end of the rings is fitted into an internal seat of an ogival applicator 92, already known, fitted with a flexible control lever 94 positioned inside the device 20 (Figure 6) .
The dimensions of the device 20 and therefore of the gripping means 28, of the patch 30, and of the elastic means 72 are decided on according to the dimensions of the vessel 26 and of the vascular prosthesis 56 which must be connected to it. Obviously, it may be advisable to build a number of devices 20 in different sizes storing them in sterile containers on the basis of the dimensions and the type of connection which can be realized with them.
During the operation, after having prepared the patient in the usual manner for this type of operation, and after having cut a tubular section of the vascular prosthesis 56 to a suitable size, the device is fixed to the free end of the vascular prosthesis 56. The ogival applicator 92 is then introduced into the end opening of
the vascular prosthesis 56 to be connected to the vessel 26 until the flange, comprising the upper ring patch 70 associated with the upper arms 36 of the gripping means 28, lies against the edge 96 of said vascular prosthesis 56. Then, acting on the control lever 94 (arrow "i" and "h" in Figure 6) the applicator 92 is removed from the end of the device. The elastic means 72, no longer held in the applicator 92, will open radially against the internal surface of the vascular prosthesis 56 taking with them the tubular patch 66. The applicator 92 is then extracted acting on the control lever 94 in order to pass it through the device 20 which is now spread and firmly fixed to the vascular prosthesis 56. This is because said elastic means 72 act by pressure against the internal surface of the vascular prosthesis 56 ensuring that the device 20 remains fixed to the vascular prosthesis 56. This connection will be enveloped in the natural tissues which will form on the surfaces of the device and the prosthesis once these are lapped by the blood conveyed by the vessel 26. These natural tissues will create a seal between the internal surface of the vessel and the internal surface of the patch (which will eventually become enclosed in them) and the internal surface of the vascular prosthesis 56.
The device 20 fixed at the end of the vascular
prosthesis 56 is then introduced into the lumen 22 previously made in the wall 24 of the exposed vessel 26 (arrow "g" of Figure 7) . During this operation the quick release 88 is carefully held outside the vessel 26. The device 20 is introduced into the lumen 22 until the flange comprising the upper ring patch 70 associated with the upper arms 36 lies against the external surface 40 of the vessel 26. The device 20 is then pressed against the wall 24 of the vessel 26 in order to anchor the hooked end 48 of the clips 32 in the wall 24.
Once the device 20 is positioned in the lumen, by pulling (arrow wf" in Figure 7) the quick release 88 in the suture thread 86, which holding devices the bundled lower arms 38, the quick release knot is released and on removing the suture thread 86 the lower arms 38 are released of the clips 32. The elastic action of the gripping means 28 pushes the lower ring patch 58 associated with the arms 38 against the internal surface 42 of the vessel 26 and anchors the hooked end 48 in the wall 24, firmly blocking the device 20 in the vessel 26 (Figure 8) . After connecting the opposite end of the vascular prosthesis 56 in the same manner the circulation of the blood will recreate the tissues that envelop and hold the patch 30, as described above, to the vessel 26 and the vascular prosthesis 56.
The procedure for the connection of the device 20, in the case of patch 30 as a patch-stop 74 on the lumen 22, is entirely identical to the procedure described above. In particular, since it is not necessary to connect the device to any vascular prosthesis 56, it will be sufficient to introduce the device 20, with the lower arms 38 bundled, into the lumen 22 and release the quick release knot for it to firmly grip the edge 34 of the lumen 22 with the clips 32 and anchor the device 20 to the edge 34, and to stretch the circular patch 76 to form a perfect closure for the lumen 22 (Figure 11) .
In the case of a end-to-end connection, it is necessary to open both arms 36, 38 of the clips 32 beforehand (Figure 13) . In this case, the internal arms 38 are tied beforehand with suture thread 98, after gathering them into a bundle towards the axis 100 of the end of the tubular patch 78. The external arms 36 are also tied in a bundle using a second suture thread 102, after turning them almost 180° around the curl 46 (arrows "m" in Figure 13) . After introducing (arrow "e" in Figure 13) the bundled internal arms 38 until the central section 44 of the clips 32 lies against the edge 34 of the vessel 26, by pulling the quick releases 104 and 106 of the suture threads 98 and 102 the bundles will be released and the internal surface 42 and the
external surface 40 of the edge 34 of the vessel 26 will be gripped by the arms 38 and 36 firmly connecting the tubular patch 78 to the vessel 26 (arrows wc" and ,xd" in Figure 13) .
It is evident from the above description that the device 20 for connecting at least one patch 30 on a lumen 22 in a vessel 26 for the conveyance of organic fluids is extremely rapid and precise to apply.
A further advantage of the invention is that the manual skill required for the application of the device is limited to the insertion of the same in the natural vessel 26 and the releasing of the threads 86, 98 and 102 which keep the arms 36 and 38 of the clips 32 bundled in an open position.
Of particular advantage is the fact that during the procedure for application of the device to a vessel it is not necessary to use instruments, which means that the connection between the device forming the subject of the invention and the edges of the lumen occurs thanks to the spontaneous movement of the gripping means into the closed position when they are released from the removable holding means, without the need to use equipment or instruments to close the device. This considerably reduces the invasiveness of the operation on the patient as well as the probability of procedural
errors. Moreover in the case of narrow natural vessels, where it is practically impossible to attach a patch 30 to the vessel by means of suturing, the device 20 forming the subject of this invention makes it possible to make connections with the same ease and efficiency as connections in larger size blood vessels 26, such as for example the aorta.
The reduction of the operating times also makes it possible to reduce the period for which the patient is kept under anaesthetic. Reduced operating times also make it possible to limit loss of blood and blood transfusions to the patient and, in some cases, to limit the times of extracorporeal circulation.
Obviously variations and/or additions to the procedures described and illustrated above can be envisaged.
Where the device is to be fitted to vessels with thin walls, it is possible to use clips 32 without the central section 44. In this case the upper or external to the vessel 26arm 36, is linked to the lower internal to the vessel 26 arm 38, by a curled stretch or a curl 110 (Figure 14) .
In the case of a head-to-head connection of two natural vessels, the device 20 includes two gripping means 28 positioned opposite each other and designed to
hook the clips 32 into the edges of the free ends of the two vessels. Said gripping means 28 are connected to one another by the use of the same thread rings 54 previously positioned alternately in the openings 47 of the curls 46 of the first of the gripping means 28 and in the corresponding openings 47 of the curls 46 of the second of the gripping means 28. Thus, when the two natural vessels are connected head-to-head (end-to-end connection) , the edges of the ends of the two vessels are practically joined.
In the examples described so far, the arms are elastically influenced thanks to the elastic nature of the material of which the clips 32 are made. Alternatively, separate elastic means can be used to influence the arms 36 and 38 when closing the clip 32.
In another embodiment, the connecting device 20 has clips 32 in smart alloys with shape memory. For example, the clip 32 is of a smart alloy with shape memory with the phase transition in a temperature range which will hold the device in an open position when it is not installed, for example because it is cold, i.e. below the phase transition temperature, and in the closed position when it is warmed above the phase transition temperature. For example, the material in smart alloy has a phase transition temperature between 20°C and 36°C
and in particular between 25°C and 30°C.
In another embodiment of the invention the connecting device is built in smart alloy with shape memory which has particular elastic characteristics throughout the working temperature range, for example from 15°C to 45°C. Thus it is possible to take advantage of the specific elastic characteristics by constructing the device with gripping means 28 in thread of very narrow cross section and therefore very light in weight, but at the same time strong and capable of considerable elastic strain which facilitates the application of the grip device 28 on very cross sectional narrow vessels 26. In this case, the use of a clip 32 without the curled section 46 is particularly recommended, where the upper arm 36 is linked by an arcuate section 112 to the lower arm 38 (Figure 15) . In this embodiment of the invention, in the case of a by-pass, it is necessary to bundle both arms 36, 38 of the clips by tying them with suture thread 114 (Figure 17) . Since the arms 36, 38 of the clips 32 are bundled before the operation, in this embodiment of the invention the device 20 proposed is also extremely rapid and precise to apply. It is in fact sufficient to introduce the bundled internal or lower arms 38 into the lumen 22 cut in the wall of the vessel 26 and pull the quick releases 116 of the knots in the
threads 114 which tie the bundles of arms 36, 38. Once the arms 36, 38 are freed, thanks to the elastic action, the clips 32 will close firmly anchoring themselves to the edge 34 of the lumen 22.
In another embodiment of the invention the gripping means 28 are formed of two opposed half-rings 120, 121 with arms 36, 38 projecting radially from the ends. In particular, each half-ring 120 or 121 covers half of a circumference equal to the perimeter of the lumen 22 of the vessel 26 and lies more or less in a first plane P (more precisely the half-ring lies on a cylindrical surface corresponding to the external surface of the vessel) . Two opposed arms 36 and 38 are present for each half-ring 120 or 121 at the free ends 122 and 124. The arms lie on a second plane Q orthogonal to the first and connect to the half-ring 120 or 121 by means of a stretch bent into a half-curl or a half-curl 126 which can connect with the half-curl 126 of the opposing half- ring 121 or 120. Therefore each clip 32 has an arm 36 protruding from the first half-ring 120 and a second arm 38 protruding from the second half-ring 121. Said first and second arms 36, 38 are opposed to each other.
In another embodiment of the invention, the patch 30 is associated to the gripping means 28 by means of biocompatible adhesive or glue.
Obviously, the patch 30 can be associated to the gripping means 28 and the elastic means 72 either internally or externally. In other words, the patch 30 can be placed between the gripping means 28 or the elastic means 72 and the wall 24 of the vessel 26 or the vascular prosthesis 56. Alternatively, the gripping means 28 or the elastic means 72 may be placed between the patch 30 and the natural vessel 26 or the vascular prosthesis 56. In both cases the patch 30 will be enveloped in the natural tissues which in time will form in the area of the operation.
In yet another embodiment of the invention the gripping means 28 comprise a flat structure 128 of synthetic biocompatible material with elastic characteristics. Said flat structure 128 includes a circular crown 130 or ring from which a series of elastic lamellae 132 spread forming the arms 36, 38 of the clips 32 (Figure 19) . Said flat structure 128 of biocompatible synthetic material is easily constructed. For example, said flat structure can be obtained by cutting a sheet of biocompatible synthetic material, or by casting or pressing in a special die.
The patch 76 is associated with said flat structure. For example, the patch 76 is glued to the surface of the flat structure 128 which is placed
towards the vessel. In other words the patch 76, for example a patch-stop, is glued to the surface of the circular crown 130 facing the vessel and to the lamellae 132 or arms 38 which grip the wall of the vessel from the inside (Figure 20) .
Alternatively, a patch 76 of the same size is glued only to the circular crown 130, leaving the elastic lamellae 132 for gripping the wall of the vessel free. It is particularly advantageous, where the flat structure 128 is constructed by casting, for the patch 76 to be enveloped in the circular crown 130 during its construction (Figure 19) .
In order to apply the connecting device 20 described above to a lumen 22 in a vessel 26, it is necessary first of all to bundle alternatively the first lamellae 132 or the external arms 36 towards the side of the device which will remain outside the vessel, and the second lamellae 132 or the internal arms 38 towards the side of the device which will be introduced into the vessel through the lumen 22 (Figure 20) . Said bundles of arms 36 and 38, respectively are wound by suture thread 134 positioned in special seats 50 created by channels or shapes in the lamellae 132 so that the seats 50 are turned towards the walls of the vessel. Said suture thread 134 is tied in a quick release knot, so that the
arms 36, 38 can be freed once the device has been inserted into the lumen closing with the pressure of the gripping means the wall of the vessel, firmly connecting the device fitted with the patch to the vessel.
The order in which the lamellae 132 are bundled may differ from the above description. For example, it is possible to bundle towards the side of the device which will remain outside the vessel every other lamella 132 or every third lamella 132.
Generally, the gripping means may comprise arms or elements which in the closed position exercise a gripping action thanks to opposing forces. This closing action may be assisted by a hooking action, where suitable hook portions are provided on the arms or elements, such as, for example, the above mentioned hooked ends 48 on the arms 36, 38.