JP7523478B2 - Implantable Vascular Access Devices - Google Patents

Description

The present invention relates to the field of hemodialysis devices, in particular to vascular access devices for hemodialysis that can be permanently implanted in patients with pre-existing arteriovenous fistulas, and the present invention includes both devices and is advantageously capable of carrying out the surgical and hemodialysis procedures described herein.

Hemodialysis is a treatment that allows the extracorporeal circulation of blood to be purified in a special hemodialysis machine, which is equipped with a semipermeable membrane through which only (or at least the majority of) the toxic substances to be removed can pass. Patients suffering from severe renal failure are the subjects of this treatment. To carry out hemodialysis, it is of course necessary to create vascular access at two points: one from which the blood to be purified is taken, and the other from which the filtered blood is reinjected into the circulatory system. The most commonly used vascular access is the arteriovenous fistula (also known as FAV), which is achieved by a surgical procedure and creates a permanent connection between a vein and an artery. It involves widening the venous part of the arteriovenous fistula, since the arterial pressure is significantly higher than the venous pressure. In this way, the two aforementioned points of vascular access can be pre-arranged in the arteriovenous fistula, allowing the passage of a relatively large blood flow and reducing the time required for hemodialysis. Despite this, hemodialysis is a long treatment, actually requiring 3 to 4 hours, and must be carried out two or three times a week. As a result, the arteriovenous fistula periodically and frequently undergoes trauma resulting from the insertion of metallic needles, known as fistula needles, made of metal and having a diameter of the order of 1.6 mm as well as a sharp cutting tip. These needles are inserted into the arteriovenous fistula and may create trauma in the wall portion of the FAV opposite the entrance portion. In particular, to insert into the vein, the fistula needle is inserted at a first inclination to the skin. To insert the fistula needle into the FAV, this inclination must be changed and the needle positioned parallel to the fistula. This creates stress, pain and trauma for the patient (for which the only evidence is the wound), the risk of completely penetrating the FAV from side to side, individual complications arising from the fragility of the vein and a high probability of infection. Indeed, even when administering local anesthesia, the patient still feels pain once the anesthesia effect wears off. To obviate this, the "buttonhole" method has been developed. This involves inserting needles in the FAV at always the same two points (take and return) with the same angle and depth, with the goal of creating a kind of subcutaneous channel in the scar tissue extending from the skin surface to the FAV. Through this subcutaneous channel, needles are inserted prior to every hemodialysis session. Special devices have also been created that are inserted into the channel from dialysis session to dialysis session in order to keep the channel open until it is stably formed. It is obviously fundamentally important to ensure the same angle and the same depth during each insertion of the needle. In this regard, first the above-mentioned fistula needles (with sharp cutting) must be used for a certain number of dialysis sessions, and only then can needles suitable for the buttonhole method be used. These needles have the same diameter as the fistula needles, and a non-cut, beveled tip. Therefore, highly specialized personnel are needed to carry out this method, especially in the early stages of treatment. Moreover, the buttonhole method is correlated with a high incidence of infections with respect to the use of cutting needles, and is not recommended in cases of too much or too little subcutaneous tissue and in cases of wounded skin. Recently, vascular access devices for hemodialysis have been developed that can be permanently implanted in patients with arteriovenous fistulas. These devices have a fixation surface that is designed to be fixed to the outer wall of the FAV near the skin, and a funnel-shaped channel that leads into the thinnest part of this fixation surface. Once embedded therein, the device remains stuck in the muscle. Even with these devices, it is necessary to use the fistula needle inserted into the skin and muscle to find the center of the funnel-shaped channel and gradually penetrate the wall of the FAV at the fixation surface of the device as it is inserted. This device does not eliminate the risk of crossing the fistula needle from side to side of the vein (V), and furthermore, due to the funnel-shaped channel, it is not possible to change the inclination of the fistula needle and therefore not to insert it deeply, and it is not possible to shorten the treatment time, which is limited by the cross section of the fistula needle, as with the buttonhole method.

US Patent Publication No. 2010/318016 and US Pat. No. 4,822,341 describe another vascular access device for hemodialysis that can be permanently implanted in patients with pre-existing arteriovenous fistulas. The device according to US Pat. No. 4,822,341 is implanted in a continuous manner in a blood vessel. Once implanted, the device has an inlet hole and an outlet hole for blood withdrawal and reinfusion, respectively. The device includes a sliding valve for opening and closing the hole by sliding longitudinally against the blood vessel, which is placed subcutaneously once the device is implanted. It is clear that to open and close the hole, the operator must slide the sliding valve inside the patient to counter the action of the tissue at the valve, and that the operator must insert the fistula needle into the skin and muscle to find the center of the hole once it has been opened. The objective difficulty of sliding a valve implanted in the body makes the device practically unapplicable. Thus, a need arises to perform hemodialysis sessions while limiting patient stress, pain, and trauma, damage to the FAV, potential infections at the blood access sites of the FAV, the need for highly specialized personnel, and associated costs. An additional need arises to reduce the number of surgeries a patient must undergo to prepare the patient for hemodialysis, with the goal of reducing the risks associated with surgery and injury and pain caused to the patient. Additionally, there is a recognized need to reduce the cost and/or time for hemodialysis, as well as the need for specialized medical operators.

US Patent Application Publication No. 2010/318016 U.S. Pat. No. 4,822,341

The object of the present invention is to obviate or limit the disadvantages associated with hemodialysis using FAVs. In particular, the primary object of the present invention is to provide hemodialysis treatment while limiting patient stress, pain, and trauma, damage to the FAV or other blood vessels, potential infection of the blood access site of the FAV, the need for highly specialized personnel, and the associated costs. Additionally, another object of the present invention is to provide a vascular access device that is structurally simple, economical, and reliable in use. Another object of the present invention is to enable reduced hemodialysis time.

The above mentioned object is achieved by the subject matter of independent claim 1. The vascular access device for hemodialysis of claim 1 can be permanently implanted in series with a pre-existing FAV, vein or artery or can hydraulically connect a vein to an artery . A sterile package containing at least one disposable device for withdrawing and/or injecting blood in an arteriovenous fistula is opened and used for each hemodialysis session, and the connecting element of the disposable device can be hydraulically connected to the blood inlet or blood outlet tubing of the hemodialysis machine by inserting the first end of the medical cannula through the second and first conduits of the vascular access device according to the invention (possibly piercing the patient's skin with a needle only at the second end of the second tubular element of the second conduit), acting on the flow control and/or cut-off device to allow the cannula flow. Since the only body element that is pierced is the skin, it heals easily. In particular, when treated with a suitable fistula pressure pad with silver and/or another bactericidal and/or healing agent, the pain caused to the patient during the hemodialysis session is significantly reduced. According to the invention, it is also clear that there is no risk of side-to-side penetration of the vein, artery or arteriovenous fistula during the hemodialysis session when the insertion for taking from or returning to the vein is realized with a cannula and when it is performed with a vascular access device, as well as when inserting the free end of the treatment cannula for the cannulation procedure. This end is naturally non-cutting and sufficiently flexible to be adapted and inserted first into the second conduit in the vascular access device for hemodialysis and then into the first conduit. As a result, there is no risk of damaging the FAV. Additionally, the first conduit can have the same internal diameter as the FAV, and the vein or artery and the cannula can have an internal diameter of 0.1-0.2 mm smaller than the internal diameter of the first conduit, i.e., 2.0-4.0 mm, depending on the associated thickness. Thus, significantly larger than the diameter of the fistula needle of 1.6 mm. This allows a significant increase in the amount of blood taken in the FAV and the amount of blood returned during hemodialysis. Thus, by appropriately sizing the filtering surface of the semipermeable membrane in the hemodialysis device based on the blood flow that can flow through a cannula with an internal diameter of 2.0-4.0 mm, it is possible to significantly limit the personnel time and costs for a single hemodialysis treatment, while increasing personnel productivity.

It should be noted that the use of the vascular access healing device allows the valve access of the healing device around the cylinder of the healing device by inserting it into the second and/or third conduit at the vascular access point of the body. In fact, by leaving the healing device at this location for a few days, removing it for periodic vascular access treatments (at least 2-3 times a week) and reinstalling it after each treatment, it is possible to obtain a permanent vascular access with a healed and permanently open vascular access hole in a relatively short time. The vascular access hole leads to the second and/or third conduit in the vascular access device of the present invention, to which are preferably connected the first and second valves, respectively, which close the second or third conduit, respectively, by hydraulic pressure. This dramatically limits blood loss. The permanent vascular access with the healed access hole is penetrated by a cannula for cannulation, in particular a cannula included in a sterile package . Therefore, it is not necessary to use a fistula needle to perform dialysis. As a result, dialysis can be performed by an operator who is not highly specialized in dialysis. Because the cannula entry in the permanent vascular access is significantly simplified compared to the prior art, it makes it easier to connect the hemodialysis machine to the patient, and because no needle is used, the discomfort and pain felt by the patient that may damage the vein, artery, or FAV is reduced.

According to the characteristics of the person undergoing dialysis, the time required to obtain a permanent vascular access with a healed and permanently open vascular access hole may vary from 4 to 12 weeks, or from 8 to 10 weeks. During this period, and in any case, if the healing device is not used, dialysis will not be performed or will be performed using a central venous catheter until the implantation of the vascular access device is adapted (i.e. ready for use), which will then be removed. In addition to the advantages mentioned above, the vascular access device for hemodialysis according to claim 1 advantageously further allows to select the vessel to be implanted. In fact, it can be implanted in series with an artery (A), a vein, a pre-existing arteriovenous fistula, or, more preferably, between an artery and a vein, so that the vascular access device itself builds an artificial arteriovenous fistula. In this case, in a single operation, a permanent vascular access and outlet, as well as an artificial arteriovenous fistula, are created. Thereby limiting the number of operations the patient needs to undergo and, as well as the resulting risk of postoperative complications and the discomfort suffered by the patient.

Features of the present invention are set forth below, and related preferred but non-exclusive embodiments are described with reference to the accompanying figures and drawings.

FIG. 1 is a schematic perspective view of a first embodiment of a vascular access device for hemodialysis according to the present invention. FIG. 1 is a schematic side view of a first embodiment of a vascular access device for hemodialysis according to the present invention. FIG. 1 is a schematic top view of a first embodiment of a vascular access device for hemodialysis according to the present invention. FIG. 1 is a schematic front view of a first embodiment of a vascular access device for hemodialysis according to the present invention. 1D 的结构上的结构用经过步骤的第1实施例的经过步骤。 FIG. 1D is a schematic cross-sectional view of a first embodiment of a vascular access device for hemodialysis according to the present invention, the first embodiment of the present invention is a cross-sectional view of a section of the vascular access device for hemodialysis according to the present invention. FIG. 2 is a schematic perspective view of a second embodiment of a vascular access device for hemodialysis according to the present invention. 2 is a schematic side view of a second embodiment of a vascular access device for hemodialysis according to the present invention. FIG. 1 is a schematic top view of a second embodiment of a vascular access device for hemodialysis according to the present invention. FIG. 1 is a schematic front view of a second embodiment of a vascular access device for hemodialysis according to the present invention; FIG. 2E is a schematic cross-sectional view of a second embodiment of a vascular access device for hemodialysis according to the present invention taken along plane 2E-2E of FIG. 2D. FIG. 2C is an enlarged view of detail K of FIG. 2B. FIG. 13 is a schematic perspective view of a third embodiment of a vascular access device for hemodialysis according to the present invention. FIG. 2 is a top view of the sterile package . 1 is a side view of another embodiment of a disposable device for drawing and/or injecting blood in accordance with the present invention. FIG. FIG. 5C is a top view of the disposable device of FIG. 5B. 5C is a cross-sectional view of the disposable device of FIG. 5B along axis V _D -V _D of FIG. 5C. FIG. 5C is a front view of the disposable device of FIG. 5B. FIG. 5B is an enlarged view of detail A of FIG. 5D. FIG. 5C is a perspective view of the disposable device of FIG. 5B. FIG. 5C is an enlarged view of detail C of FIG. 5G. FIG. 5C is an enlarged view of detail B of FIG. 5G. 1 is a side view of another embodiment of a disposable device for drawing and/or injecting blood. FIG. 5L is a top view of the disposable device of FIG. 5M is a cross-sectional view of the disposable device of FIG. 5L taken along axis _VN - _VN of FIG. 5M. FIG. 5L is a front view of the disposable device of FIG. FIG. 5B is an enlarged view of detail D of FIG. 5N. FIG. 5L is a perspective view of the disposable device of FIG. FIG. 5C is an enlarged view of detail D of FIG. 5G. FIG. 5C is an enlarged view of detail D of FIG. 5G. 1 is a schematic cross-sectional view of a first embodiment of a portion of a collection and/or infusion system for hemodialysis , connected to an arteriovenous fistula in a use configuration; FIG. 1 is a schematic cross-sectional view of a second embodiment of a portion of a collection and/or infusion system for hemodialysis , connected to an arteriovenous fistula in a use configuration; FIG. FIG. 13 is a schematic cross-sectional view of a third embodiment of a portion of a collection and/or infusion system for hemodialysis , connected to an arteriovenous fistula in a use configuration. FIG. 13 is a side view of a fourth embodiment of a vascular access device according to the present invention. FIG. 9B is a rear view of the device of FIG. 9A. FIG. 9B is a top view of the device of FIG. 9A. 9C is a cross-sectional view of the device of FIG. 9A taken along the plane _IXD - _IXD of FIG. 9C. 9B is a cross-sectional view of the device of FIG. 9 along plane IX _E -IX _E of FIG. 9B. FIG. 9D is an enlarged view of detail J of FIG. 9D. 9D is a cross-sectional view of the device of FIG. 9A taken along the plane IX _G -IX _G of FIG. 9D. 9G is a cross-sectional view of the device of FIG. 9A taken along the plane IX _H -IX _H of FIG. 9G. FIG. 9C is an enlarged view of detail K of FIG. 9H. FIG. 9B is a schematic perspective view of the device of FIG. 9A, seen from below. FIG. 9B is a schematic perspective view of the device of FIG. 9A, seen from above. FIG. 9B is an exploded top view of the device of FIG. 9A. FIG. 10B is a rear view of the exploded device of FIG. 10B is a cross-sectional view of the exploded device of FIG. 10A taken along plane X _C -X _C of FIG. 10A. 10B is a cross-sectional view of the exploded device of FIG. 10A taken along plane _XD - _XD of FIG. 10B. FIG. 10B is a perspective view of the exploded device of FIG. FIG. 10D is an enlarged view of detail X of FIG. FIG. 13 is a side view of a fifth embodiment of a vascular access device for hemodialysis according to the present invention. FIG. 11B is a rear view of the device of FIG. FIG. 11B is a top view of the device of FIG. 11C is a cross-sectional view of the device of FIG. 11A taken along the plane XI _D -XI _D of FIG. 11C. 11B is a cross-sectional view of the device of FIG. 11A taken along plane XI _E -XI _E of FIG. 11B. FIG. 11B is an enlarged view of detail K of FIG. 11D is a cross-sectional view of the device of FIG. 11A taken along the plane XI _G -XI _G of FIG. FIG. 11B is a schematic perspective view of FIG. 11A as seen from below. FIG. 11B is a schematic perspective view of FIG. 11A as seen from above. FIG. 11B is an exploded view of the device of FIG. FIG. 12B is a rear view of the exploded device of FIG. 12A. 12B is a cross-sectional view of the exploded device of FIG. 12A taken along plane XII _C -XII _C of FIG. 12A. 12D is a cross-sectional view of the exploded device of FIG. 12A taken along plane XII _D -XII _D of FIG. 12B. FIG. 12B is a perspective view of the exploded device of FIG. 12A. FIG. 12C is an enlarged view of detail K of FIG. 12D. FIG. 13 is a side view of a sixth embodiment of a vascular access device according to the present invention. FIG. 13B is a rear view of the device of FIG. 13A. FIG. 13B is a top view of the device of FIG. 13A. 13C is a cross-sectional view of the device of FIG. 13A taken along plane XIII _D -XIII _D of FIG. 13C. 13D is a cross-sectional view of the device of FIG. 13A taken along plane XIII _E -XIII _E of FIG. 13D. FIG. 13D is an enlarged view of detail K of FIG. FIG. 13B is a bottom perspective view of the device of FIG. 13A. FIG. 13B is a top perspective view of the device of FIG. 13A. FIG. 13B is an exploded view of the device of FIG. 13A. FIG. 14B is a rear view of the exploded device of FIG. 14A. 14B is a cross-sectional view of the exploded device of FIG. 14A taken along plane XIV _C -XIV _C of FIG. 14A. 14B is a cross-sectional view of the device of FIG. 14A taken along plane XIV _D -XIV _D of FIG. 14B. FIG. 14D is an enlarged view of detail Z of FIG. FIG. 14B is a perspective view of the device of FIG. 14A. FIG. 13 is a side view of a seventh embodiment of a vascular access device according to the present invention. FIG. 13 is a bottom perspective view of a seventh embodiment of a vascular access device according to the present invention. FIG. 13 is a top perspective view of a seventh embodiment of a vascular access device according to the present invention. FIG. 13 is a side view of an eighth embodiment of a vascular access device according to the present invention. 13 is a bottom perspective view of an eighth embodiment of a vascular access device according to the present invention. FIG. 13 is a top perspective view of an eighth embodiment of a vascular access device according to the present invention. FIG. 13 is a side view of a ninth embodiment of a vascular access device according to the present invention. 13 is a longitudinal cross-sectional view of a ninth embodiment of a vascular access device according to the present invention. FIG. 13 is a bottom perspective view of a ninth embodiment of a vascular access device according to the present invention. FIG. 13 is a top perspective view of a ninth embodiment of a vascular access device according to the present invention. FIG. 16 is a side view of a tenth embodiment of a vascular access device according to the present invention. FIG. 18B is a rear view of the device of FIG. 18A. FIG. 18B is a top view of the device of FIG. 18A. 18B is a cross-sectional view of the device of FIG. 18A taken along the plane XIIX _D -XIIX _D of FIG. 18B. FIG. 18B is a view of the device of FIG. 18A from the P side. 18B is a cross-sectional view of the device of FIG. 18A taken along the plane XIIX _F -XIIX _F of FIG. 18A. FIG. 18D is an enlarged view of detail J of FIG. FIG. 18B is a cross-sectional view of the device of FIG. 18A taken along the plane XIIX _H -XIIX _H of FIG. 18A. 18H is a cross-sectional view of the device of FIG. 18A taken along plane XIIX _I -XIIX _I of FIG. 18H. FIG. 18B is a bottom perspective view of the device of FIG. 18A. FIG. 18B is a top perspective view of the device of FIG. 18A. 13 is a side view of an eleventh embodiment of a vascular access device according to the present invention. FIG. 19B is a rear view of the device of FIG. 19A. FIG. 19B is a top view of the device of FIG. 19A. 19B is a cross-sectional view of the device of FIG. 19A taken along the plane XIX _D -XIX _D of FIG. 19B. 19B is a cross-sectional view of the device of FIG. 19A taken along plane XIX _E -XIX _E of FIG. 19B. FIG. 19D is an enlarged view of detail B of FIG. FIG. 19C is an enlarged view of detail C of FIG. 19E. 19B is a cross-sectional view of the device of FIG. 19A taken along plane XIX _H -XIX _H of FIG. 19A. 19H is a cross-sectional view of the device of FIG. 19A taken along plane XIIX _I -XIIX _I of FIG. 19H. FIG. 19B is a bottom perspective view of the device of FIG. 19A. FIG. 19B is a top perspective view of the device of FIG. 19A. 1A-1D are diagrams illustrating locations where a vascular access device according to the present invention may be implanted. 1A-1D are diagrams illustrating locations where a vascular access device according to the present invention may be implanted. 1A-1D are diagrams illustrating locations where a vascular access device according to the present invention may be implanted. 1 is a schematic front view of a healing device for valve access according to the present invention in a first associated configuration; FIG. 1 is a schematic side view of a healing device for valve access according to the present invention in a first associated configuration; FIG. 1 is a schematic top view of a healing device for valve access according to the present invention in a first associated configuration; FIG. 1 is a schematic perspective view of a healing device for valve access according to the present invention in a related first configuration; FIG. 2B is a schematic side view of the device of FIG. 2A in a related second configuration. 2B is a schematic front view of the device of FIG. 2A in a related second configuration; FIG. 2B is a schematic perspective view of the device of FIG. 2A in a related second configuration;

With reference to the drawings, reference number (1) refers to a vascular access device for hemodialysis, permanently implantable in a patient with an arteriovenous fistula. (1) refers to a vascular access device for hemodialysis (with both single and double vascular access) permanently implantable in a patient, (102) refers to a disposable device for blood withdrawal and/or infusion, (500) refers to a healing device for valve access, (100) refers to a sterile package, and (1000) refers to a withdrawal and/or infusion system for hemodialysis . As can be seen from the figures, the first to third embodiments refer to a single access vascular access device according to the invention (see Figures 1A to 4 and Figures 6 to 8), while the fourth to eleventh embodiments refer to a double access vascular access device of the invention, which allows double vascular access (see Figures 9 to 19N). The dual-access vascular access device of the invention is indeed capable of withdrawing blood to be dialysis from the patient and reinfusing the dialyzed blood back into the patient, e.g. withdrawing blood from the second tubular element (203) and reinfusing blood into the third tubular element (303) or vice versa, whereas a single-access vascular access device only allows one access, either inlet or outlet, and therefore two of them must be implanted in each patient.

According to the present invention, a single-access vascular access device (1) is a vascular access device (1) made of biocompatible and sterilizable materials, comprising:
- an associated first tubular element (2) having longitudinally associated first and second ends (21) and defining a first conduit (22) extending from the first to the second end (21);
an associated second tubular element (3) having longitudinally associated first and second ends (31, 32) and defining a second conduit (33) extending from the associated first to the second ends (31, 32), the first end (31) of the second tubular element (3) being fixed to the first tubular element (2) at an intermediate position between the first and second ends (21) of the second tubular element (3) such that the second conduit (33) is in fluid communication with the first conduit (22) and such that the second end (32) of the second tubular element (3) is on a first side relative to the first tubular element (2) (see Figures 1A, 1B, 1E, 2A, 2B, 2E and 4);
a first fastening means (4) with a first plurality of through holes (41) and fixed to the first tubular element (202) and/or the second tubular element (3) (preferably they are fixed to the second tubular element (3)), the first plurality of through holes (41) being arranged at a second end (32) of the second tubular element (3) on a first side with respect to the first tubular element (2), the vascular access device (1) being adapted and dimensioned for implantation in the arm of a patient having an arteriovenous fistula for hemodialysis, with a first conduit (22) sandwiched in continuity with the arteriovenous fistula for blood flow between a first part (51) and a second part (52) of the arteriovenous fistula, The first end (21) and the second end (21) of the first tubular element (2) are fixed to the first and second parts (51) and (52) of the arteriovenous fistula, respectively, at the associated ends of the associated parts (51, 52) and at the second end (32) of the second tubular element (3), and a first fixing means (4) in which the first plurality of through holes (41) are positioned subcutaneously in the implanted skin area (7) for fixing the first plurality of through holes (41) to the implanted skin area (7) by fixing the first plurality of suture stitches (60), thereby fixing the second end (32) of the second conduit (33) to the implanted skin area (7). It should be noted that due to the second conduit (33) being in fluid communication with the first conduit (22) and such that the second end (32) of the second tubular element (3) rests on the first side of the first tubular element (2), the first end (31) of the second tubular element (3) cannot be fixed to the first tubular element (2) in an intermediate position between the first and second ends (21) of the second tubular element (3). In fact, the first end (31) of the second tubular element (3) is fixed in an intermediate position between the first and second ends (21) of the first tubular element (2), as can be seen in Figures 1A, 1B, 1E, 2A, 2B, 2E and 4.

The vascular access device (1) of the present invention of a double access type as shown in Figs. 9 to 19 is a vascular access device (1) for hemodialysis that can be permanently implanted in a patient, and is made of biocompatible and sterilizable materials:
an associated first tubular element (202) having longitudinally associated first and second ends (221, 223) and defining a first conduit (222) extending from the first to the second ends (221, 223);
an associated second tubular element (203) having longitudinally associated first and second ends (231, 232) (see FIG. 10F) and defining a second conduit (233) extending from the associated first to the second ends (231, 232), the first end (231) of the second tubular element (203) being fixed to the first tubular element (202) adjacent the first end (221) of the first tubular element (202) such that the second conduit (233) is in fluid communication with the first conduit (222) and the second end (232) of the second tubular element (203) is on a first side relative to the first tubular element (202);
an associated third tubular element (303) having longitudinally associated first and second ends (331, 332) and defining a third conduit (333) extending from the associated first end to the associated second end (331, 332) (see FIG. 19G), the first end (331) of the third tubular element (303) being fixed adjacent to the second end (223) of the first tubular element (202) such that the third conduit (333) is in fluid communication with the first conduit (222) and the second conduit (233) and the second end (332) of the third tubular element (303) is on a first side relative to the first tubular element (202);
- a first fastening means (4) fixed to the first tubular element (202) and/or the second tubular element (203) and comprising a first plurality of through holes (41), the first plurality of through holes (41) being arranged on a first side with respect to the first tubular element (202) and at a second end (232) of the second tubular element (203);
- a second fastening means (304) fixed to the first tubular element (202) and/or the third tubular element (303) and comprising a second plurality of through holes (41), the second plurality of through holes (41) being arranged on a first side with respect to the first tubular element (202) and at a second end (332) of the third tubular element (303);
wherein the vascular access device (1) comprises:
a first position in an artery (A), vein (V) or pre-existing arteriovenous fistula (F) (see Figs. 20C, 20B and 20A, respectively), in which the first conduit is sandwiched between a first and a second portion of the artery (A), vein (V) or pre-existing arteriovenous fistula (F) respectively and in continuity with the artery (A), vein (V) or pre-existing arteriovenous fistula (F) with respect to blood flow, and the first and second ends (221, 223) of the first tubular element (202) are fixed to the first and second portions (51) and (52), respectively;
a second location (see FIG. 20D ) between the artery (A) and the vein (V), in which the associated first or second end (231, 232) of the first tubular element (202) is fixed to the artery (A) and the remaining of the associated first or second end (231, 232) of the first tubular element (202) that is not fixed to the artery (A) is fixed to the vein (V) such that the first conduit (222) hydraulically connects the artery (A) to the vein (V) to create an artificial arteriovenous fistula (FA);
The device is adapted and dimensioned for implantation in a patient, preferably in the patient's arm, at a first location and a second location, where the first and second plurality of through holes (41) of the second end (232) of the second tubular element (203) and the second end (332) of the third tubular element (303) are positioned subcutaneously in the implantation skin area (7) such that the first and second plurality of through holes (41) of the second end (232) of the second tubular element (203) and the second end (332) of the third tubular element (303) can be fixed to the implantation skin area (7) by corresponding first and second plurality of suture stitches (60), thereby fixing the second end (232) of the second conduit (233) and the second end (332) of the third tubular element (303) to the implantation skin area (7).

The dual access vascular access device is not only implantable in succession in the blood vessels (vein, artery, and pre-existing arteriovenous fistula), but also advantageously allows for the performance of the following surgical method for implanting the device, which includes the steps of:
The method includes the steps of pre-positioning the dual access vascular access device of the present invention; performing a surgical incision in the wall of the vein (V) at the implantation site; performing a surgical incision in the wall of the artery (A) at the implantation site; hydraulically connecting the vein and the artery via a first conduit (222) hydraulically connected at the associated ends to a second conduit (233) and a third conduit (333), respectively; fixing the associated first or second end (231, 232) of the first tubular element (202) fixed to the artery (A) at the associated surgical incision; 32), using the remainder not fixed to the artery (A) at the associated surgical incision, the first conduit (222) hydraulically connects the artery (A) to the vein (V) to construct an artificial arteriovenous fistula (FA), and positioning the second end (232) of the second tubular element (203) and the second end (332) of the third tubular element (303) to fix the first and second plurality of piercing holes (41) to the vein (V) such that they are positioned subcutaneously at the implanted skin area (7); and fixing the first and second plurality of piercing holes (41) to the implanted skin area (7) by corresponding first and corresponding second plurality of suture stitches (60).

With the goal of obtaining permanent vascular access with a healed and permanently open vascular access hole, the applicant has also developed a vascular access healing device (500):
a cylinder (505) insertable inside the vascular access and having an associated longitudinal axis of deployment; and an associated insert (502) with associated longitudinal first and second ends and a distally tapered tip (503) fixed to the first end of the cylinder (505) (preferably coaxial with the cylinder), the insert being adapted to be inserted between the first valve (50) and the first plate (4) or between the second valve (50) and the second plate (50). an associated insertion portion (502) insertable into the second conduit (33, 233) or the third conduit (333) of the vascular access device (1) for hemodialysis according to any one of claims 4, 7, 8, 9 and 10 from the associated second end (32, 232, 332) so as to exclusively block a portion of the second conduit (33, 233) or the third conduit (333), respectively, configured between the associated second end (32, 232, 332) and the associated insertion portion (502) of the vascular access device (1) for hemodialysis according to any one of claims 4, 7, 8, 9 and 10;
- an associated connection (504) fixed to the second end of the cylinder (505);
- associated first and associated second gripping tabs (501), both of which have connection parts (504) to enable the first and second gripping tabs (501) to assume an associated first configuration (see Figures 21A to 21D), in which they are substantially coplanar, and a second configuration (Figures 21E to 21F), in which they are opposed to each other, and which are connected on both sides to the cylinder axis and have the possibility of relative movement with respect to the connection parts (504), and in both the first and second configurations the first and second gripping tabs (501) cannot be inserted into the second conduit (33, 233) or the third conduit (333).

In a related embodiment of the vascular access healing device, the related cylinder is inclined to the connection by an angle (λ) that is identical to the angle β (see FIG. 1A ) (see FIGS. 21B, 21D, and 21G, respectively), at which angle the second tubular element (3, 203) or the third tubular element (303) is inclined to the first plate (4) or the second plate (304), respectively.

21A-21G, the length L3 of the insert (502) is comprised between 2 mm or 2.5-5 mm, preferably between 1-3 mm, to avoid contact with the valve (50). The gripping tab (501) may have the following dimensions: L4 is comprised between 3-6 mm, preferably between 4.5 mm, and L5 is comprised between 4.5-6 mm, preferably between 5 mm. The diameter θ of the cylinder, which of course depends on the dimensions of the second and third conduits, is advantageously between 1.5-2 mm, preferably between 1.75 mm. The width L6 of the vascular access healing device (500) may be between 10-15 mm, preferably about 12.5 mm, while the length L7 is between 7-10 mm, preferably about 8.5 mm.

The sterile package (100) includes at least one disposable device (102) for the withdrawal and/or injection of blood in an arteriovenous fistula, which comprises:
- a treatment cannula (103) for cannulation procedures having an associated first end (108) and an associated second end (109), the first end (108) being free and capable of cannulating a pre-existing arteriovenous fistula (F), artery (A) or vein (V) of a patient via the second conduit (33, 233) and the first conduit (22, 222) or via the third conduit (333) and the first conduit (222), both in double and single access devices;
- a pre-disposed flow control and/or cut-off device (104) for controlling and/or cutting off the flow of liquid in the treatment cannula (103);
a connecting element (106) fixed to the second end (109) of the treatment cannula ( 103 ) allowing hydraulic connection to the blood inlet or blood outlet tubing of the hemodialysis machine;
an optional access element arranged between the first end (108) of the cannula and the control and/or shutoff device (104) and defining an access channel (181) (see Figures 5F and 5P) hydraulically connected to the first end (108) of the cannula; and reversible closing means (180) at the distal end of the access element for reversibly closing the access channel (181) to allow injection of a liquid into the access channel (181) and for causing said liquid to flow towards the first end (108) of the treatment cannula (103);
- an optional first gripping element (120) arranged between the first end (108) and the control and/or shutoff device (104), and/or a second gripping element (130) arranged close to the connection element (106). Of course, the package also comprises an associated wrapping (101) sealed and made of a suitable material to allow sterility of the contents. For example, the wrapping (101) can be made using a sheet material that is transparent to ultraviolet light, and/or ionizing radiation (gamma and/or beta radiation), and/or microwaves. By appropriately selecting both the associated configuration and dimensions of the vascular access device (1) and the collection and/or infusion disposable device (102) contained in the sterile package (100), it is sufficient to open the package for each hemodialysis session to easily obtain a collection and/or infusion system (1000) for hemodialysis, comprising both the vascular access device (1) and the collection and/or infusion disposable device (102). The first free end (108) of the treatment cannula (103) is free and cannulated to the patient's arteriovenous fistula, vein, or artery via the second conduit (33, 233) and the first conduit (22, 222) and/or via the third conduit (333) and the first conduit (22, 222) of the vascular access device (1). The system 1000 makes it possible to achieve the above-mentioned objectives over the prior art.

Thus, the withdrawal and/or infusion system (1000) for hemodialysis comprises a vascular access device (1) for hemodialysis according to the invention, which can be double access or single access, and at least one disposable device (102) for withdrawal and/or infusion of blood in an arteriovenous fistula (F), a vein (V) or an artery (A), said disposable device (102) comprising:
- a treatment cannula (103) for cannulation procedures having an associated first end (108) and an associated second end (109), the first end (108) being free and capable of being cannulated into a pre-existing arteriovenous fistula (F), artery (A) or vein (V) of a patient via the second conduit (33, 203) and the first conduit (22, 222) of the vascular access device (1) or via the third conduit (333) and the first conduit (22, 222);
- a pre-disposed flow control and/or cut-off device (104) for controlling and/or cutting off the flow of liquid in the treatment cannula (103);
a connecting element (106) fixed to the second end (109) of the treatment cannula (108) allowing hydraulic connection to the blood inlet or blood outlet tubing of the hemodialysis machine;
an optional access element arranged between the first end (108) of the cannula and the control and/or shutoff device (104) and defining an access channel (181) (see Figures 5F and 5P) hydraulically connected to the first end (108) of the cannula; and reversible closing means (180) at the distal end of the access element for reversibly closing the access channel (181) to allow injection of a liquid into the access channel (181) and for causing said liquid to flow towards the first end (108) of the treatment cannula (103);
- an optional first gripping element (120) arranged between the first end (108) and the control and/or shutoff device (104), and/or a second gripping element (130) arranged in the vicinity of the connecting element (106),
Here, the harvesting and/or injection system (1000) may optionally comprise at least one healing device (500) of vascular access , preferably a plurality of healing devices (500), advantageously between 8 and 30.

In the case of a dual-access vascular access device, it is preferred that the system include two single-access devices (102) for collection and/or injection.

It should be noted that the access elements and closure means are capable of aspirating any thrombus present in both single and double access devices. Additionally, the access elements and closure means allow for the injection of an anticoagulant into the first conduit (22, 222). The anticoagulant can be, for example, heparin, such as a heparin lock, sodium citrate, urokinase, and mixtures thereof.

In order to improve the sterilization and mechanical resistance of the vascular access device (1), it is preferably made of metal, more preferably titanium. However, the invention can also include the construction using biocompatible and sterilized plastic materials so that they are not resorbed by the body, as explained below. If the vascular access device for hemodialysis has a second end (32, 232) of the second tubular element (3, 203) and a second end (332) of the third tubular element (303), a first and a second plurality of through holes (41) can be constructed with two through holes (41), preferably arranged on opposite sides, in the second conduit (33, 232) and the conduit (333), respectively, in order to improve their fixation to the skin area (7) for implantation. If constructed with three through holes, they are preferably arranged around the second conduit (33, 233) and the third conduit (333) at an angle of 120° apart. If a greater number of through holes (41) are included, they may be arranged at the second end (32, 232) of the second tubular element (3, 203) along a closed loop surrounding the second conduit (33, 233) (see Figs. 1C and 2C). They may even be more preferably equiangular. The through holes (41) are preferably at least six in number. The same applies to the holes at the second end (332) of the third tubular element (303), if present. In order to advantageously facilitate the insertion of the treatment cannula (103) into the second conduit (33) and the first conduit (22, 222) and/or into the first conduit (222) and the third conduit (333), at least one of the two, preferably both, of the cannula and the conduit has an associated elliptical or, more preferably, circular internal cross-section. The conduits (22, 33) advantageously have cylindrical inner walls.

Naturally, the first tubular element (2, 202) and the second tubular element (3, 203) have associated longitudinal axes of deployment (24, 34) that are incident on each other and define two angles of incidence, one complementary to the other. This also applies to the first and third tubular elements in the case of a double-access vascular access device. A preferred embodiment of a vascular access device (1) for hemodialysis is one in which the first tubular element (2) and the second tubular element (3) have associated longitudinal axes of deployment that are incident on each other at a minimum angle (α) that is an acute angle. This angle may preferably be comprised between 25 and 60°, more preferably between 25 and 50°, even more preferably between 28 and 30° or between 43 and 48°, 25° and 45°, and/or (preferably) where the first tubular element (202) and the third tubular element (303) are present, have their associated longitudinal deployment axes incident on each other at a minimum angle (α) comprised between 25 and 50°, preferably 25°. The minimum angle (α) may advantageously be 25°, 35° or 45°. Naturally, depending on the angle (α), the measured length (L2) of the second tubular element (3) must be appropriately dimensioned along the associated longitudinal deployment axis in order to dimension the vascular access device (1) such that, by fixing the first tubular element (2) to the FAV, the second end (32) of the second tubular element (3) is under the skin (7). However, the surgeon is perfectly able to select a suitable vascular access device (1) for implanting the associated first tubular element (2) in the continuous FAV and the second end (32) of the second tubular element (3) under the skin (7) in the patient based on the patient's physical characteristics (gender, diagonal, muscle mass, fat mass).

In an embodiment of the vascular access device for hemodialysis (1) of the present invention, the first fastening means (4) can originate from the second end (32, 232) of the second tubular element (3, 203) and/or (preferably) the second fastening means (304), if present, can originate from the second end (332) of the third tubular element (303). For example, the first and/or second fastening means (4) can be constructed by a plurality of arm bands (not shown) arranged in spokes with respect to the second conduit (33), each arm band comprising one or more through holes of the first plurality of through holes (41).

It is particularly preferred that the first fastening means (4) comprises a plate (4) having an associated main through hole (44), where the first plurality of through holes (41) are arranged around the main through hole (44) and the plate (4) is fixed to the second end (32) of the second tubular element (3, 203) at the associated first surface, whereby the second conduit (33, 233) is accessible from the associated main through hole; and/or (preferably) where present, it is particularly preferred that the second fastening means comprises a second plate (304) having an associated main through hole. Here, the second plurality of through holes (41) are arranged peripherally with respect to the associated main through hole, and another second plate (304) is fixed to the second end (332) of the third tubular element (303) at the associated first side, whereby the third conduit (333) is accessible from the associated main through hole (44). This simplifies the realization of the vascular access device (1). The main through hole (44) advantageously has the same cross section at the second end as the second conduit (33), so that they coincide and facilitate the insertion of the treatment cannula (103) into the first conduit (22).

In an advantageous aspect of the invention, the plate (4) is fixed to the second tubular element (3) with its associated second side toward its second end (45) opposite to its associated first side and is arranged along a plane parallel to the longitudinal axis of extension (24) of the first tubular element (2, 202). And/or (preferably) if present, the second plate (304) is fixed to the third tubular element (303) with its associated second side (45) opposite to its associated first side and is arranged along a plane parallel to the longitudinal axis of extension (24, 224) of the first tubular element (2, 202). As shown in the embodiment of Figures 9 to 19, the second and third tubular elements (203, 303) are preferably arranged such that their associated longitudinal axes of extension are transverse from the first side of the first tubular element (202). Because this facilitates the collection of blood to be dialyzed and the return of the dialyzed blood to the patient. The second surface (44) is defined to face the inside of the skin (7) and is preferably arranged at a relative distance (D2) to the longitudinal deployment axis (24) of the first tubular element (2, 202) comprised between 5 and 10 mm, preferably between 6.5 and 8.0 mm. This distance (D2) also naturally depends on the minimum angle (α), the above considerations being valid with respect to the dimensioning of the vascular access device (1) and the surgeon's choice.

For the purpose of easily fixing the vascular access device (1) for hemodialysis, both single and double access, if the vascular access is permanently implanted in series with the pre-existing FAV and the artery (A) or vein (V), the first and second ends (21, 221, 223) of the first tubular element (2, 202) can each advantageously be provided with a third plurality of through holes (28) (see Figs. 1A-1C, 6 and 16A-17D), which are arranged along the associated transverse fixation sector and allow the first and second ends (21, 221, 223) of the first tubular element (2, 202) to be fixed, respectively, to the ends of the first and second parts (51) and (52) of the arteriovenous fistula by means of a third plurality of suture stitches (80), visible in Fig. 6. The suturing can be performed with the ends of the first and second portions of an artery (A), vein (V), or pre-existing arteriovenous fistula (F) positioned on the outside (see FIG. 6) or inside of the first and/or second ends of the first tubular portion. In the latter case, it is preferred that at least one, and preferably both (as shown in FIG. 1E) between the first and second ends (21, 221, 223) of the first tubular element (2, 202) each comprises an associated internal housing with an associated internal annular abutment surface (27) defined by the first conduit (22, 222) for abutting (preferably entirely) when fitted to the ends of the first and second parts (51) and (52) of the artery (A), vein (V) or pre-existing arteriovenous fistula (F) and the terminal annular surfaces at the ends of the first and second parts (51) and (52) of the artery (A) (see FIG. 20C) or vein (see FIG. 20B) arteriovenous fistula (see FIGS. 7 and 20A). This not only improves fixation, but also prevents the cannula from hitting the end annular surface once the free end (108) of the treatment cannula (103) is inserted into the second conduit (33) and the first conduit (22) during cannulation of the free end (108) of the artery (A), vein (V), or part of the pre-existing arteriovenous fistula (F). Of course, if the housing (25) is present only on one side between the first and second ends (21, 221, 223) of the first tubular element (2, 202), this will be the end opposite the minimum angle (α).

Preferably, the third plurality of through holes (28) is at least four, preferably at least six, more preferably at least eight. They are advantageously arranged at equal angles. The through holes (41, 28) in the first, second and third plurality of through holes must of course be of a size and configuration such that they can be traversed by a surgical needle. During the suturing operation by the surgeon on the incised skin (7) and the two pre-existing FAV (F), vein (V) or two parts of the artery (A) for each of the first and second plurality of through holes (28), the surgeon will pass each suture stitch through a different through hole.

In another fixation mode of the first and second ends (21) of the first tubular element (2, 202) to two parts of a pre-existing FAV (F), vein (V), or dissected artery (A), the ends can be fixed to the ends of the first part (51) and second part (52) of the pre-existing arteriovenous fistula of the vein (V) or artery (A), respectively, using surgical adhesive (not shown).

For the purpose of improving the fixation of the first and/or second ends of the first tubular element (2, 202) with surgical adhesive, each may be provided with an associated transverse fixation sector, e.g. having a relatively irregular outer surface with a plurality of concaves, slots or grooves. In a preferred embodiment of the invention, the associated transverse fixation section has an associated plurality of external annular grooves (29) (see Figs. 2A-2E and 3) coaxial with the longitudinal deployment axis (24) of the first tubular element (2, 202), improving the fixation of the first and second ends (21) of the first tubular element (2, 202) to the first and second portions, respectively, of a pre-existing arteriovenous fistula of a vein (F) or artery (A) with surgical adhesive.

Considering the average body size of a patient, it is preferred that the vascular access device (1) for hemodialysis in the present invention, single or double access, has the following features, either alone or in combination:
the first conduit (22, 222) has an associated smallest internal diameter comprised between 2 and 5 mm, preferably between 2.5 and 4.0 mm, and/or an associated external diameter comprised between 3 and 7 mm, between 4 and 6.0 mm, preferably between 4 and 6.0 mm, and/or
the second conduit (33, 233) and/or the third conduit (333), if present, have an associated smallest internal diameter comprised between 2.0 and 5.0 mm, preferably between 2.5 and 4 mm, and/or an associated external diameter comprised between 3.0 and 6.0 mm, preferably between 3.5 and 5.0 mm; and/or
the first plurality of through holes (41) and/or the second plurality of through holes (41), if present, are arranged at a distance comprised between 5 and 9 mm, preferably between 6.5 and 8 mm, from the longitudinal axis of development (24) of the first tubular element (2, 202), depending on the angle between the longitudinal axes of development, and/or
the holes (41) in the first and/or second plurality of through holes (41) have dimensions between 1.1 and 2 mm, preferably 1.6 x 0.9; and/or
the holes in the third plurality of through holes (28) have dimensions between 0.6 and 0.9 mm, preferably 0.7×0.85, preferably 0.8;

It is particularly preferred, especially in the case of double-access vascular access devices, that the length of the first tubular element is 3-10 cm, more preferably 4-12 cm, 8-12 cm or advantageously 4-6 cm, because in this way it is possible to implant it between the vein and the artery, especially in the arm or leg of the patient, and because in an artificial conduit of this length, the same anatomical structure that is naturally present inside the vein and the artery is reproduced in the internal structure of the conduit. This significantly reduces the risk of thrombus and blockage in the first conduit (22, 222). Furthermore, a length of the first tubular element (2, 202) of at least 4 cm, preferably 5-6 cm, ensures that the blood taken during dialysis does not contain blood that has just been returned during dialysis. If the vascular access device for hemodialysis is of the double-access type and is used to obtain an artificial arteriovenous fistula, the length is preferably at least 8-12 cm, which of course depends on the anatomy of the patient. Additionally, it is highly preferred if the device, or at least the inner walls of the first, second and third conduits (22, 222, 33, 233, 333), are made of metal or biocompatible plastic material. In the second case, the device can be made by molding or 3D printing. Preferred materials, especially for making double access devices, are silicone, polydimethylsiloxane PDMS, PTFE, preferably ePTFE, DACRON, preferably silicone and/or polydimethylsiloxane, and ePTFE, more preferably ePTFE, because they tend to be less thrombogenic and allow better endothelinization of the associated first conduit (22, 220), which prevents the access device from becoming blocked and also reduces rejection.

The vascular access device (1) for hemodialysis according to the present invention preferably further comprises a first valve (50). The first valve (50) is connected to the second conduit (33, 233) and configured to hydraulically close the second conduit (33, 233) in an associated closed configuration and to hydraulically open the second conduit (33, 233) in an associated open configuration. In particular, in the case of a double-access vascular access device, and therefore in the case of an associated third tubular element (303), it is advantageous to further comprise a second valve (50). The second valve (50) is connected to the third conduit (333) and configured to hydraulically close the third conduit (333) in an associated closed configuration and to hydraulically open the third conduit (333) in an associated open configuration. In particular, the presence of the first valve (50) in the case of a single access vascular access device, and the presence of the first and second valves (50) in the case of a double access, advantageously allows to limit blood loss once hemodialysis is finished, improving its acceptability by the patient. The valve (50) advantageously stops the blood flow as soon as the cannula of the disposable blood withdrawal and/or infusion device (102) according to the invention is withdrawn from the first conduit or from the second conduit at the end of dialysis. In this way, it makes it possible to minimize blood loss from a patient undergoing dialysis, especially when the patient is treated with a silver-containing blood access fistula pressure pad, commercially available as EMODIAL S.r.l., as described in EP 2296717 and ITBO 20080303.

The first and/or second valves (50) are preferably located distal to the second ends of the second conduits (3, 33) and/or third conduits (333), respectively. Use of the vascular access healing device allows for healing of the valve access around the cylinder of the healing device, as previously described, by insertion into the second and/or third conduits at a vascular access point in the body.

The first and/or second valve (50) is advantageously configured to allow entry into the associated conduit (3, 233, 33) via the associated second end (21, 232) of the associated tubular element (2, 203, 303) of the first end (108) of the treatment cannula (103) of the sampling and/or injection disposable device (102).

In an alternative preferred embodiment of the single and double access vascular access device for hemodialysis, the first valve (50) is arranged between the second end (21, 232) of the second tubular element (2, 203) and the first plate (4). The first plate (4) comprises a first engagement means (41) which engages, in an associated first face, the second end (21, 232) of the second tubular element (203) and/or, if a third tubular element (303) is present, the second plate (304) and the second valve (50). The second valve (50) is disposed between the second end (332) of the third tubular element (303) and the second plate (304), which has second engagement means (41) for engaging the second end (21, 232) of the third tubular element (303) on the associated first surface (see Figures 9A to 10F).

In a preferred embodiment of a vascular access device for hemodialysis, both single and double access, the first valve (50) is arranged on a second face of the first plate (4) opposite to the associated first face and is provided with a third engagement means (54) for frictionally engaging with the second end (21, 232) of the second tubular element (203) and/or with a fourth engagement means (55) pre-disposed on the first plate (4). When the third tubular element (303), the second plate (304) and the second valve (50) are present, the second valve (50) is arranged on a second side of the second plate (304) opposite to the associated first side and comprises a fifth engagement means (54) for frictionally engaging with the second end (332) of the third tubular element (303) and/or the sixth engagement means (55) previously disposed on the second plate (304) (see Figs. 11A-14E). The first engagement means (41), and/or the second engagement means (41), and/or the third engagement means (54), and/or the fifth engagement means (54) may comprise associated engagement elements (41, 54) protruding from the first side by frictionally engaging with the second end (21, 232).

However, as shown in the drawings of the vascular access device for hemodialysis, both single and double access, it is preferred that the first valve (50) and/or the second valve (50), if present, have an associated through slot (56) which makes the two working edges identical. In the associated closed configuration of the first and/or second valve (50), the working edges come into contact and prevent the passage of fluid through the valve (50). The first and/or second valve (50) are elastically deformable to achieve an associated open configuration in which the working edges move away from each other and allow the passage of fluid through the slot (50) (see Figs. 18A-18N, especially 18F). In a preferred embodiment of the invention in the vascular access device for hemodialysis, both single and double access, the first valve (50) and/or the second valve (50), if present, can be provided with an elastically deformable element. It does not deform in the associated closed configuration and obstructs the associated second conduit (33, 233) and/or the associated third conduit (333), respectively, and in the associated open configuration it is compressed and does not obstruct the associated second conduit (33, 233) and/or the associated third conduit (333).

In an alternative preferred embodiment of the vascular access device for hemodialysis, single and double access, a first valve (50) having an associated perimeter is disposed in the second conduit (33, 233) at a first end (31, 231) of the second tubular element (3, 203), with a first portion (151) of the associated perimeter fixed to the second conduit (33, 233) and a second portion (152) free in the remainder of the associated perimeter. It faces the second conduit (3, 233) in a closed configuration and contacts the second conduit (3, 233) to hydraulically close the second conduit and/or (preferably) the third tubular element (303), if present, the second plate (304), and the second valve (50). The second valve (50) has an associated perimeter and is disposed in the third conduit (333) at a first end (332) of the third tubular element (303) with a first portion (151) of the associated perimeter fixed to the third conduit (333) and a remaining free second portion (152) of the associated perimeter, which faces the second conduit (233) in a closed configuration and contacts the second conduit (233) to hydraulically close the second conduit (233). The first and/or second valve (50) is elastically deformable to achieve an associated open configuration in which the associated second portion at the associated periphery hydraulically opens the second conduit (3, 233) and/or the third conduit (333), respectively, without contacting the second conduit (3, 233) and/or the third conduit (333), respectively (see Figures 19A-19M, in particular Figures 19F and 19G).

In a particularly preferred embodiment of the invention, the vascular access device for hemodialysis with the third tubular element (303) according to the invention with double access further comprises first and second contact surfaces (401, 402) (see Figs. 18D, 18N, 19E and 19N) originating from the first and second ends (221, 223) of the first tubular element (202). Each of the first and second contact surfaces (401, 402) is configured to partially face a transverse section of the outer wall of the blood vessel (A, V) in which a surgical incision is made and which surrounds the surgical incision for the purpose of hydraulically connecting the associated surgical incision to the first conduit (222) in order to facilitate the fixation of the first and second ends (221, 223) of the first tubular element (202) to the wall, respectively. In this case, in the above-mentioned surgical method, the step of pre-arranging the vascular access device (1) for hemodialysis comprises that the double access vascular access device (1) has first and second contact surfaces (401, 402). The step of fixing the first and second ends (231, 232) of the first tubular element (202) to the vein and the artery can advantageously comprise positioning the first and second contact surfaces (401, 402) at the respective transverse sections of the vein and artery facing the relevant transverse sections and completely surrounding the relevant surgical incision. Furthermore, in this case, according to a particularly preferred aspect of the invention, each of the first and second contact surfaces (401, 402) comprises a fourth plurality of through holes (48) (Figures 19E and 1M). The fourth plurality of through-holes (48) are pre-disposed around the surgical incision to allow fixation by associated plurality of through-holes (see Figs. 18D, 18N, 19E and 19N) in the first and second contact surfaces (401, 402) and corresponding suture stitches penetrating the wall of the blood vessel (A, V). Alternatively, it is preferred that each of the first and second contact surfaces (401, 402) (see Figs. 18D, 18N, 19E and 19N) is a continuous surface, smooth and/or jagged to enhance fixation to the wall of the blood vessel (A, V) using surgical adhesive. In this case, in the above-mentioned surgical method, the step of fixing the first or second end (231, 232) of the first tubular element (202) to the vein and artery can advantageously include gluing the first and second contact surfaces (401, 402) to the transverse sections of the vein and artery, respectively, using a surgical adhesive, with the first and second contact surfaces (401, 402) facing the transverse sections of the vein and artery, respectively, and completely surrounding the associated surgical incision.

In order to maximize the blood withdrawal and infusion rates during hemodialysis, both the sterile package and the hemodialysis withdrawal and/or infusion system (1000) are particularly preferred. The first conduit (22) and the second conduit (33) have a relative minimum inner diameter, and the cannula has a relative outer diameter that is 0.2-0.3 mm smaller than the gap between the minimum inner diameter of the first conduit (22) and the minimum inner diameter of the second conduit (33). This in effect allows for a higher blood flow for withdrawal and/or infusion.

For purposes of maintaining sterility, both in the sterile packaging and in the hemodialysis collection and/or infusion system, it is preferred that the access element has an associated connection end that is distal to the first end (108) of the treatment cannula (103) and engageable with a needleless syringe. The access element comprises an elastically deformable element disposed in the access channel (181). The access channel (181) and the elastically deformable element are configured and arranged together such that when the connection end is disengaged, the elastically deformable element does not deform and obstructs the access channel (181) to prevent the passage of liquids and aerosols, and when the connection end is engaged with a needleless syringe, the elastically deformable element is compressed by the needleless syringe and does not obstruct the access cannula (181) to hydraulically connect the syringe to the first end (108) of the treatment cannula (103). In this package and system, the access element, once implanted, allows the insertion of any anticoagulant into the access device, while the closure means (180) can be constructed or preferably equipped with a frictionally connected cap or lid or a valve. If the first gripping means is present, the access element can be arranged on the first gripping means (120), between the first gripping means (120) and the control and/or shutoff device (104) (see FIG. 5C). The first and/or second gripping means can be constructed by a typical "butterfly" element, which is usually applied on treatment cannulas.

To facilitate insertion of the first end (108) of the treatment cannula (103) of the vascular access device (1) on the exact side of the first conduit (2, 202) via the second conduit (33, 203) and the first conduit (22, 222), or via the third conduit (333) and the first conduit (22, 222), the first conduit (22, 222) may be provided with first and/or second protrusions (250). The first and/or second protrusions (250) are positioned between the second conduit (33, 202) and the first end (221) of the first tubular element (2, 202), and between the third conduit (333) and the second end (223) of the first tubular element (202), respectively, on the opposite side of the second conduit (33, 203) and the opposite side of the third conduit (333), and are adapted to allow the first end (108) of the treatment cannula (103) to pass over the protrusions and to advance towards the first and second ends (221, 223) of the first tubular element (202), respectively. To achieve the protrusion (250), it is possible to deform the first tubular element (202) from the outside to obtain a corresponding concave surface (251) on the opposite side relative to the second and/or third tubular elements (3, 202, 303) (see Figures 17A to 17C).

The system preferably also comprises a syringe, more preferably packaged in a syringe, advantageously a needleless syringe, containing the injectable anticoagulant liquid composition.

It should be understood that the foregoing has been described as a non-limiting example, and that any variations in the nature of the actual application fall within the scope of the present invention, as described above and as claimed in the following claims.

Claims (9)

1. A vascular access device for hemodialysis, permanently implantable in a patient having an arteriovenous fistula and made of biocompatible and sterilizable materials, comprising:
an associated first tubular element (2, 202) having longitudinally associated first and second ends (21 , 221, 223 ) and defining a first conduit (22 , 222 ) extending from said first end (2) to said second end (21, 221 , 223 );
an associated second tubular element (3, 303) having longitudinally associated first and second ends (31, 32 , 231, 232 ) and defining a second conduit (33 , 233 ) extending from the associated first end to the associated second end (31, 32 , 231, 232), said first end (31 , 231 ) of said second tubular element (3 , 303 ) being in fluid communication with said first conduit (22) and said second end (32 , 232 ) of said second tubular element (3 , 303 ) being on a first side with respect to said first tubular element (2 , 202 ); an associated second tubular element (3 , 203) fixed to said first tubular element (2, 202 ) at an intermediate position between said first end and said second end (21 , 221 ) of said first tubular element (2, 202);
a first fixing means (4) with a first plurality of through holes (41) and fixed to the first tubular element (2 , 202 ) and/or the second tubular element (3 , 303 ), the first plurality of through holes (41) being arranged at a second end (32 , 232 ) of the second tubular element (3 , 203 ) on a first side with respect to the first tubular element (2, 202 ); the vascular access device (1) is adapted and dimensioned to be implanted in the arm of a patient having an arteriovenous fistula for hemodialysis, with the first conduit (22) sandwiched between a first part (51) and a second part (52) of the arteriovenous fistula in continuity with the arteriovenous fistula for blood flow therein, and the first tubular element (2, 202) is adapted and dimensioned to be implanted in the arm of a patient having an arteriovenous fistula for hemodialysis, with the first conduit (22) sandwiched between a first part (51) and a second part ( 52) of the arteriovenous fistula in continuity with the arteriovenous fistula for blood flow therein; the first and second ends (21) of the second tubular element (3, 303) are fixed to the first and second portions (51, 52) of the arteriovenous fistula, respectively, at the associated ends of the associated portions (51, 52) and the second end (32, 232 ) of the second tubular element (3 , 303 ); and a first fixing means (4) in which the first plurality of through holes (41) are subcutaneously positioned at the implanted skin area (7) for fixing the first plurality of through holes (41) to the implanted skin area (7) by fixing the first plurality of suture stitches (60), thereby fixing the second end ( 32 , 232 ) of the second conduit (33, 233) to the implanted skin area (7). an associated second tubular element (203) fixed to the first tubular element (202) adjacent to the first end (221) of the first tubular element (202) such that the second conduit (233) is in fluid communication with the first conduit (222) and such that the second end (232) of the second tubular element (203) is on a first side relative to the first tubular element (202);
a third tubular element (303) having associated first and second longitudinal ends (331, 332) and defining a third conduit (333) extending from the associated first end to the associated second end (331, 332), the first end (331) of the third tubular element (303) being fixed to the first tubular element (202) adjacent the second end (223) of the first tubular element (202) such that the third conduit (333) is in fluid communication with the first conduit (222) and the second conduit (33, 233) and the second end (332) of the third tubular element (303) is on a first side relative to the first tubular element (202) ;
a second fastening means (304) fixed to said first tubular element (202) and/or said third tubular element (303) and comprising a second plurality of through holes (41), said second fastening means (304) being arranged on a first side with respect to said first tubular element (202) and at said second end (332) of said third tubular element (303);
The vascular access device (1) comprises:
a first position of the patient in an artery (A), vein (V) or pre-existing arteriovenous fistula (F), wherein the first conduit is sandwiched between a first portion (51) and a second portion (52) of the artery (A), vein (V) or pre-existing arteriovenous fistula (F) in continuity with respect to blood flow with the artery (A), vein (V) or pre-existing arteriovenous fistula (F), and the first and second ends (21, 221, 223) of the first tubular element (202) are fixed to the first portion (51) and the second portion (52), respectively;
a second position of the patient between an artery (A) and a vein (V), wherein the associated first or second end (31, 32, 231, 232) of the first tubular element (202) is fixed to the artery (A) and the remaining associated first or second end (31, 32, 231, 232) of the first tubular element (202) not fixed to the artery (A) is fixed to the vein (V) such that the first conduit (222) hydraulically connects the artery (A) to the vein (V) to form an artificial arteriovenous fistula (FA);
It is compliant and sized to be embedded in
2. The vascular access device of claim 1, wherein the first and second plurality of through holes (41) in the second end (32, 232) of the second tubular element (203) and the second end (332) of the third tubular element (303) are positioned subcutaneously in the implantation skin area (7) for implantation at the first and second locations such that the first and second plurality of through holes (41) in the second end (32, 232) of the second tubular element (203) and the second end (332) of the third tubular element (303) can be fixed to the implantation skin area (7) by corresponding first and second plurality of suture stitches (60), thereby fixing the second end (32, 232) of the second conduit (233) and the second end (33, 332) of the third tubular element ( 303 ) to the implantation skin area (7). The first fixing means (4) originates from the second end (32, 232) of the second tubular element (3, 203) and/or, if present, the second fixing means (304) originates from the second end (32, 332) of the third tubular element (3, 303), the first fixing means (4) comprises a plate (4) having an associated main through hole (44), the first plurality of through holes (41) are arranged around the main through hole (44), the plate (4) is arranged on the associated first side such that the second conduit (33, 233) is accessible from the associated main through hole. The vascular access device according to claim 1 or 2, wherein the second fixing means, if present, comprises a second plate (304) having an associated main through hole, the second plurality of through holes (41) being circumferentially arranged with respect to the associated main through hole, and wherein another second plate (304) is fixed to the second end (332) of the third tubular element (303) at an associated first surface such that the third conduit (333) is accessible from the associated main through hole (44). The vascular access device according to claim 3, wherein the plate (4) is fixed to the second tubular element (3, 203) with its associated second surface facing the second end (45) opposite to the associated first surface and is arranged along a plane parallel to the longitudinal axis of extension (24) of the first tubular element (2, 202), and/or, if present, the second plate (304) is fixed to the third tubular element (303) with its associated second surface (45) opposite to the associated first surface and is arranged along a plane parallel to the longitudinal axis of extension (24, 224) of the first tubular element (2, 202). The vascular access device according to any one of claims 1 to 4, further comprising a first valve (50) connected to the second conduit (33, 233) and configured to hydraulically close the second conduit (33, 233) in an associated closed configuration and to hydraulically open the second conduit (33, 233) in an associated open configuration, and/or a second valve (50) connected to the third conduit (333) when the third tubular element (303) is present and configured to hydraulically close the third conduit (333) in an associated closed configuration and to open the third conduit (333) in an associated open configuration. The vascular access device of claim 5, wherein the first valve (50) and/or the second valve (50) have an associated through slot (56) that equates two operating edges, and in an associated closed configuration of the first and/or the second valve (50), the operating edges contact and prevent the passage of fluid through the valve (50), and the first and/or the second valve (50) are elastically deformable to achieve an associated open configuration in which the operating edges move away from each other to allow the passage of fluid through the slot (50). The first valve (50) has an associated perimeter and is disposed in the second conduit (33, 233) at the first end (31, 231) of the second tubular element (203), with the first portion (151) of the associated perimeter fixed to the second conduit (33, 233) and a remaining second portion (152) of the associated perimeter free, which faces and contacts the second conduit (33, 233) in an associated closed position to hydraulically close the second conduit (33, 233); and/or, when present, the second valve (50) has an associated perimeter and is disposed in the third conduit (33, 233) at the first end (332) of the third tubular element (303), with the first portion (151) of the associated perimeter fixed to the second conduit (33, 233) and a remaining second portion (152) of the associated perimeter free, which faces and contacts the second conduit (33, 233) in an associated closed position to hydraulically close the second conduit (33, 233). 6. The vascular access device of claim 5, wherein the first and/or second valves (50) have a first portion (151) of the associated periphery fixed to a second conduit (33, 233) and a remaining second portion (152) of the associated periphery free, which in the associated closed configuration faces and contacts the second conduit (33, 233) to hydraulically close the second conduit (33, 233), and wherein the first and/or second valves (50) are elastically deformable to achieve an associated open configuration in which the associated second portion of the associated periphery is not in contact with the second conduit (3, 233) and/or the third conduit (33), respectively, to hydraulically open the second conduit (3, 233) and/or the third conduit (33), respectively. The vascular access device according to any one of claims 2 to 7, further comprising first and second contact surfaces (401, 402) originating from the first and second ends (221, 223) of the first tubular element (202), respectively, each of the first and second contact surfaces (401, 402) being configured to partially face a transverse section of the outer wall of a blood vessel (A, V) in which a surgical incision has been made, completely surrounding the surgical incision for the purpose of hydraulically connecting the associated surgical incision to the first conduit (222) to facilitate fixation of the first and second ends (221, 223) of the first tubular element (202) to the wall, respectively. 9. The vascular access device of claim 8, wherein each of the first and second contact surfaces (401, 402) comprises a fourth plurality of through holes (48), the fourth plurality of through holes (48) being pre-disposed around a surgical incision to enable fixation by corresponding suture stitches penetrating associated plurality of through holes in the first and second contact surfaces (401, 402) and the wall of a blood vessel (A, V).

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