The present invention relates to a device for jointing flexible ducts. The case of the jointing of two blood vessels will more specifically be considered herein, but, generally, each of the vessels may be any type of duct with a non-rigid flexible wall.
The stump of a blood vessel, vein or artery, is a fragile piece of flesh, uneasy to handle and, conventionally, it can only be connected to another vessel by means of a sewing.
The present invention provides transforming the stump end into an object which is easy to handle and connect by equipping each stump with a connector connectable to a complementary connector.
More specifically, the present invention provides a vessel connector, comprising an internal cylinder insertable inside of a portion of the end of a vessel, and an external cylinder arranged at the external periphery of said end, one of the two cylinders being capable of expanding/compressing after its putting into place, whereby the vessel is blocked between the two cylinders after their putting into place.
According to an embodiment of the present invention, the internal cylinder is capable of expanding after its putting into place and the external cylinder is non-expandable, this external cylinder being provided with means of attachment to an external cylinder equipping another vessel.
According to an embodiment of the present invention, the external cylinder is formed of two half-cylinders associated with a temporary attachment means.
The present invention also aims at a device for jointing vessels respectively equipped with a connector, in which each of the external cylinders comprises complementary male and female connection means.
According to an embodiment of the present invention, the first vessel is equipped with a male connector and the second vessel is equipped with a female connector, the external cylinder of which has a diameter greater than that of the external cylinder of the first connector and at least the end portion of which is flexible, this end portion being surrounded with two removable half-cylinders, themselves surrounded with a stent acting in compression.
According to an embodiment of the present invention, the vessel jointing device uses a connector in which the internal cylinder penetrates into two opposite vessels and the external cylinder surrounds the external periphery of the two vessels.
The foregoing objects, features, and advantages of the present invention will be discussed in detail in the following non-limiting description of specific embodiments in connection with the accompanying drawings, among which:
FIG. 1 shows an end of a blood vessel equipped with a connector according to an embodiment of the present invention;
FIGS. 2A-2D illustrate a placing mode of the connector of FIG. 1;
FIGS. 3A and 3B illustrate an example of application of the present invention to a blood vessel jointing operation;
FIGS. 4 to 7 illustrate various alternatives of devices according to the present invention; and
FIG. 8 illustrates another embodiment of the present invention.
In the present invention, “stent” will be used to designate a hollow cylindrical object with full or open-worked walls made of a material capable of having at an initial state a first dimension (first internal and external diameters) and at a final state a second dimension (second internal and external diameters). It may be a cylinder, the internal and external diameters of which tend to increase or to decrease, or a cylinder, the internal diameter of which tends to decrease, or a cylinder, the external diameter of which tends to increase. In the case of a cylinder, the external diameter of which tends to increase, the stent will be likely to exert an expansion effort on the medium arranged at its external periphery. In the second case, the stent will be likely to exert a compressive effort on the medium located at its internal periphery.
Such stents may use various physical phenomena. It may for example be shape-memory materials, devices of pneumatic type, or osmotic effect devices. In this last case, the stent will be formed of a cylinder with a double wall, containing an osmotic material so that the pressure between the two walls increases when the stent is plunged into a liquid, one or the other of the two walls being likely to deform.
- Example of the Putting into Place of a Connector
FIG. 1 is a perspective view of a blood vessel 1 provided with a connector according to the present invention. The connector comprises a stent 2 arranged inside of the vessel and a non-expandable cylinder 3 arranged outside of the vessel. The stent is such that, once placed inside of the vessel, it tends to increase its diameter so that vessel 1 is stuck between stent 2 and cylinder 3. Hereafter, cylinder 3 intended to be used as a support will be called the “anvil”. It is preferably not a cylinder made of a rigid material, but a cylinder made of a non-extensible flexible material, for example, a biocompatible metal, fabric, or plastic cylinder.
FIGS. 2A to 2D illustrate successive steps of the putting into place of the connector of FIG. 1 at the end of a blood vessel 1 by means of an introducing device 5. The introducer has the shape of a cylinder of small diameter. It may be introduced through a percutaneous orifice. The introducer end located outside of the patient will be called the “proximal end” and the introducer end located inside of the field of operation will be called the “distal end”. The introducer is comprised of a core 6 and of a sheath 7 mobile in translation with respect to each other. An element such as a stent 2 may be housed in the distal portion of the sheath.
By exerting translational and rotational motions on the proximal end, the operator can control the orientation and the position of the distal end. Such motions enable introducing the distal end a few millimeters into the vessel. This operation may require for the stump to be held by clips (introduced by another percutaneous orifice).
The stent then remains to be released. The stent introducers enable this functionality by means of devices located at the proximal end. This phase is critical, because the stent may slide with respect to the stump. A partially reversible introducing device will preferably be chosen. Such a device enables having the stent return into its protective sheath, provided that the stent has not completely come out of it (typically, the stent must be “spread out” over less than a set percentage, for example, 80%, of its length). It should be noted that the used stent tends to have a greater diameter than the vessel (due to this difference in diameters, the stent will be able to press the vessel wall against the anvil's). Now, at this stage (FIG. 2B), the anvil has not been placed yet. There would be a risk of injuring the vessel if the stent was too spread out. It will thus only be spread out by a length that enables it to take a diameter equivalent to that of the artery (this is performed under visual control, an endoscope being installed in the operation field). It should be noted that when the stent is not too spread out, it is possible to have it undergo translation motions along the stump axis. This is only possible in the direction that would lead to the stent extraction, given the conical character of the stent when its spreading out is incomplete. This will ease the correct positioning of the stent. It should also be noted that if the operator considers that the stent is mispositioned, it is always possible to bring it back into the introducer sheath and repeat the operation. At this step of the operation, the stump has become immovably attached to the proximal end. The clip holding the stump is thus no longer necessary.
- Example of Fastening of Two Connectors
At the step illustrated in FIG. 2C, cylindrical anvil 3 is introduced from the proximal end. It is a hollow cylinder that can slide as far as the stump. A clip enables putting it in the right place. The stent release can then be complete by maneuvering the proximal end of the introducer. The stent releases all its centripetal radial compression force, thus pressing the vessel wall against the anvil (FIG. 2D).
As illustrated in FIG. 3A, two stumps to be fastened 1 and 11 are provided with male and female connectors comprising stents 2 and 12 and anvils 3 and 13. Female anvil 3 preferably has an end portion of reduced diameter. Male anvil 13 comprises an end portion made of a flexible, but non-extensible material. Further, at least the end portion of anvil 13 is surrounded with two rigid half-cylinders 14 a, 14 b, each of which is equipped at one end with a catch (small gripping excrescence) 15 a, 15 b and with a stent 16 having a tendency to contracting (decreasing its diameter). Half-cylinders 14 a, 14 b are maintained in placed against each other under the effect of the pressure exerted by stent 16.
Two clips introduced into the operation field enable handling the two stumps equipped with connectors. As illustrated in FIG. 3B, the end of anvil 3 can thus be introduced into the end of anvil 13. Clips are also used to successively grip catches 15 a and 15 b and remove rigid semi-cylinders 14 a and 14 b. The jointing is thus performed and maintained under the effect of the pressure exerted by stent 16.
According to an alternative, illustrated in FIG. 4, cylinders 3 and 13 forming an anvil are provided at their ends with fast connection male and female devices 18 a and 18 b. Such devices, such as, for example, threads, or “clipsing” devices, are very current to quickly connect pipes, in particular for those used in the medical field.
According to another alternative of the present invention, instead of specializing two specific male and female connectors at the end of two stumps to be connected, two male or two female connectors and one complementary intermediary connection part may be used. When more than two vessels are desired to be connected, for example to perform an end-to-side anastomosis, an intermediary T-shaped part to which are connected stumps equipped with connectors as described hereabove may be used.
FIGS. 5 and 6 illustrate another embodiment of the present invention in which a single stent 22 is inserted into the two ends of two vessels 1 and 11 and these two ends are altogether surrounded at their external periphery with a non-extensible cylinder 23. FIG. 5 shows the device while stent 22 is in its initial position, before expanding, and FIG. 6 shows the device while the stent is in expanded position. In this embodiment, the stent is preferably of pneumatically- or osmotically-inflatable type.
FIG. 7 shows another alternative of the present invention in which a single stent 22 is inserted into the two ends of the two assembled vessels 1 and 11 and two cylinders forming an anvil 25 and 26 are arranged at the external periphery of the vessel ends.
FIG. 8 shows another embodiment of the present invention in which a first vessel 1 is associated with a male connector while a second vessel 11 is associated with a female connector. The male connector comprises an internal stent 2 and an external stent forming an anvil. In the embodiment, the external cylinder is formed of two half-cylinders 31 a and 31 b respectively associated with grip catches 32 a and 32 b. Half-cylinders 31 a and 31 b are assembled in any selected fashion, for example, by a wire or net 33 that maintains them in place and enables them to temporarily be used as an anvil. The female connector is bell-mouthed and comprises two external half-cylinders 35 a and 35 b, respectively associated with gripping catches 36 a and 36 b. The blood vessel is everted and pressed against the bell mouth of the connector to which it is temporarily attached by clips, wires, or the like. The assembly is surrounded with a cylindrical stent 37, the internal diameter of which tends to decrease. The assembly of the male and female connectors is performed by inserting the male connector into the female connector, by cutting wire or net 33, and by successively removing half-cylinders 32 a, 32 b, then half-cylinders 36 a and 36 b after having detached them from vessel 11. Then, the connection is ensured by the two stents 2 and 37 operating antagonistically, stent 2 exerting an expansion force and stent 37 a compression force.
The external cylinder, forming an anvil, may also be provided in the various embodiments to be a longitudinally split cylinder, the two opposite portions of the split being attachable to each other after being put into place, for example by fast connection.