The invention relates to the field of haemodialysis devices. In particular, the invention relates to a vascular access device for haemodialysis permanently implantable in a patient having a pre-existing arteriovenous fistula and a sterile package containing a single-use device of collecting and/or injecting blood from and to the patient utilisable in combination with a vascular access device for haemodialysis with which a collection and/or injection system for haemodialysis can be obtained which comprises both devices and which advantageously enables carrying out the surgical and haemodialysis methods described herein.
Haemodialysis is a treatment that enables, by means of extracorporeal circulation of blood, purifying the blood in a special haemodialysis apparatus which comprises a semi-permeable membrane through which only (or at least the majority of) the toxic substances that are to be removed pass. Patients suffering from severe renal failure are subject to this treatment. Obviously, in order to carry out the haemodialysis it is necessary to create a vascular access, i.e. two points: one from which the blood to be purified is to be collected, and the other from which the filtered blood is re-injected into the circulatory system. The vascular access most generally used is the arteriovenous fistula (also known as a FAV) which is realised by a surgical operation, creating a permanent connection between a vein and an artery which involves the widening of the portion of vein of the arteriovenous fistula as the arterial pressure is much higher than the venous pressure. Therefore the two above-mentioned points of the vascular access can be predisposed in the arteriovenous fistula, as this enables passage of the relatively high blood flows, and reduces the time necessary for the haemodialysis. Notwithstanding this, haemodialysis is a long treatment, and in fact requires from three to four hours and must be carried out two or three times a week. Consequently the arteriovenous fistula is periodically and frequently subjected to the traumas deriving from the insertion of metal needles, known as fistula needles, which are made of metal, have a diameter in the order of 1.6 mm, as well as a sharp and cutting tip. The needles are to be inserted in the arteriovenous fistula and can create traumas to the portion of wall of the FAV opposite the inlet portion, in particular because in order to insert in the vein the fistula needle is inserted with a first inclination with respect to the skin and to insert it in the FAV it is necessary to change that inclination and position the needle parallel to the fistula. This causes stress, pain and traumas to the patient (the bruising alone is testimony to this), the risk of the FAV passing completely from side to side, complications for individuals who suffer from vein fragility and a high possibility of infection. In fact, even when administering local anaesthesia, the patient, once the effect of the anaesthesia has faded, still feels pain. To obviate this, the “Buttonhole” method has been developed, which includes inserting needles in the FAV always at the same two points (collection and return) with the same angulation and depth with the purpose of creating a sort of subcutaneous channel of scar tissue that extends from the cutaneous surface to the FAV through which the needles are inserted prior to every haemodialysis session. Special devices have also been created which are to be inserted into the channel from session to session in order to keep it open until the channel has been stably formed. It is clear that it is of fundamental importance to guarantee the same angulation and the same depth during each insertion of the needle. On this matter, first the above-mentioned fistula needles (sharp and cutting) have to be used for a certain number of dialysis sessions, and only after this can needles be used that are suitable for the Buttonhole method, which needles have the same diameter as the fistula and a bevelled tip which does not cut. Therefore highly specialised personnel is necessary for practising the method, especially in the early days of treatment. Further, the Buttonhole method is correlated to a greater incidence of infections with respect to the use of cutting needles and further it is not recommended in a case in which the subcutaneous tissue is too much or too little and where there is scarred skin. Recently vascular access devices for haemodialysis have been developed which are permanently implantable in a patient having an arteriovenous fistula. These devices have a fixing surface destined to be fixed to the outer wall of the FAV proximal to the skin and which comprise a funneling channel opening into the thinnest part in the fixing surface and in which, once implanted, the device remains stuck in the muscle. With these devices too, it is necessary to use a fistula needle which is inserted into the skin and the muscle, seeking to centre the funneling channel and gradually, as it is being inserted, passes through the wall of the FAV at the fixing surface of the device. This device does not do away with the risk of crossing the vein (V) with the fistula needle from side to side: further, owing to the funneling channel, there is no possibility of a variety of inclinations of the fistula needle which therefore cannot be inserted deeply, nor does it enable a reduction of the treatment time which is limited by the section of the fistula needle, alike to the Buttonhole method.
Documents US 2010/318016 A1 and U.S. Pat. No. 4,822,341 describe further vascular access devices for haemodialysis permanently implantable in a patient having a pre-existing arteriovenous fistula. The device according to U.S. Pat. No. 4,822,341 is implanted in series to a blood vessel. Once implanted, the device has an inlet hole and an outlet hole, respectively for the collection and re-injection of blood. This device includes a sliding valve for closing and opening the holes by sliding longitudinally with respect to the blood vessel, and once the device has been implanted the sliding valve is arranged subcutaneously. It is clear that in order to open and close the holes, the operator must cause the sliding valve to slide internally of the patient's body to oppose the action of the tissues at the valve, and that the operator also has to use a fistula needle, inserting it into the skin and the muscle, seeking to centre the holes, once open. Owing to the objective difficulties in sliding the implanted valve in the body, the device has virtually never had a practical application. Therefore a need emerges to carry out the haemodialysis sessions while limiting the stress, pain, and traumas for the patient, the damage to the FAV, the possibility of infections of the vascular access sites of the FAV, the need for highly specialised personnel and the related costs. There additionally emerges a need to reduce the number of operations the patient has to be subjected to in order to prepare her or him for haemodialysis with the aim of reducing the risks correlated with the operations and the disturbance and pain caused to the patient. Further, there is an acknowledged need to reduce the costs and/or times for haemodialysis, as well as the need for specialised healthcare operators.
The aim of the present invention is to obviate or limit the drawbacks correlated to haemodialysis using FAV. In particular, the main aim of the present invention is to provide a haemodialysis treatment while limiting the stress, pain, and traumas for the patient, the damage to the FAV or other blood vessels, the possibility of infections of the vascular access sites of the FAV, the need for highly specialised personnel and the related costs. Additionally, a further aim of the present invention is to realise a vascular access device which is constructionally simple and economical, as well as reliable in use. A further aim of the present invention is to enable a reduction of haemodialysis times. The above-mentioned aims are attained according to the contents of independent claims 1, 2, 10 and 13. The vascular access device for haemodialysis of claim 1 can be permanently implanted in series to the pre-existing FAV, to the vein or artery or can hydraulically connect a vein to an artery. The sterile package containing at least a single-use device of collecting and/or injecting blood in an arteriovenous fistula as defined in claim 14 can be opened and used in each haemodialysis session hydraulically connecting the connecting element of the single-use device to an inlet tube of blood or to an outlet tube of blood of a haemodialysis apparatus, by acting on the flow regulating and/or intercepting device to enable the flow of the cannula and inserting the first end of the medical cannula (possibly piercing, with a needle, the patient's skin only at the second end of the second tubular element of the second conduit) through the second and first conduit of the vascular access device implanted according to the invention. As the only body element that is pierced is the skin, which easily heals, in particular if treated with appropriate fistula pressure pads comprising silver and/or another disinfecting agent and/or a healing agent, the pain caused to the patient during the haemodialysis sessions is significantly reduced. It is further clear that, according to the invention, there is never a risk of passing from side to side of the vein, artery or arteriovenous fistula during the haemodialysis sessions as the insertion of the collecting or return device from and into the vein is achieved by cannulation and takes place at the vascular access device and with the inserting of a free end of a medical cannula for cannulation. This end is by definition non-cutting and is sufficiently flexible to conform and insert, first in the second conduit and then in the first conduit of the vascular access device for haemodialysis. Consequently there is no risk of damage to the FAV. Additionally, the first conduit can have the same internal diameter as the FAV, the vein or the artery and the cannula can have, as a function of the relative thickness, a diameter of less by 0.1-0.2 mm to the internal diameter of the first conduit, i.e. an internal diameter of 2.0-4.0 mm, therefore much greater than the diameter of the fistula needle, which is 1.6 mm. This enables notably increasing the quantity of blood collected and returned into the FAV during haemodialysis. Therefore, by appropriately dimensioning the filtering surface of the semi-permeable membrane of the haemodialysis apparatus on the basis of the blood flow that can flow into the cannula having the internal diameter of 2.0-4.0 mm, it will be possible to significantly limit the times and costs of personnel relative to a single haemodialysis treatment while increasing personnel productivity.
Note that the use of the vascular access healing device of the invention enables, by inserting it at the point of vascular access of the body and in the second conduit and/or in the third conduit, healing device the valve access about the cylinder of the healing device. In fact, by leaving the healing device for a few days in the site, removing it for periodic medication of the vascular access (at least 2-3 times a week), and replacing it, after each medication, it is possible to obtain, in a relatively short time, a permanent vascular access having a permanently open healed vascular access hole. The vascular access hole opens on the second conduit and/or on the third conduit of the vascular access device of the invention to which is preferably connected, respectively, the first or second valve, which hydraulically close the respective second or third conduit. In this way blood loss can be drastically limited. Note that the permanent vascular access having a healed access hole is passed through by a cannula for cannulation, in particular the cannula comprised in the sterile package of the invention. It is therefore not necessary to use fistula needles to carry out the dialysis. Consequently the dialysis can also be carried out by an operator who is not highly specialised in dialysis as the inlet of the cannula in the permanent vascular access is enormously simplified with respect to the prior art and further facilitates the connection of the haemodialysis apparatus to the patient. Further, as there is no use of fistula needles, the discomfort and pain felt by the patient is reduced, as is the probability of damaging veins, arteries or the FAV.
According to the characteristics of the person to be dialysed, the time required for obtaining the permanent vascular access with the permanently open healed vascular access hole can vary from 4 to 12 weeks, or from 8 to 10 weeks. In this period and in any case, in a case where the healing device of the invention is not used, until the implant of the vascular access device has matured, (i.e. is ready to be used) dialysis is not carried out or is carried out using a central venous catheter, which will then be eliminated. Additionally to the advantages set out in the foregoing, the vascular access device for haemodialysis of claim 1 further and advantageously enables choosing the blood vessel in which to implant it; in fact it can be implanted in series to an artery (A) to a vein, to a pre-existing arteriovenous fistula or, more preferably, it can be implanted between an artery and a vein to constitute in itself an artificial arteriovenous fistula. In this case, with a single operation, a permanent vascular access and outlet and an artificial arteriovenous fistula are created, thus limiting the number of operations to which the patient has to be subjected, as well as the consequent risks of post-operatory complications and the discomfort suffered by the patient.
The characteristics of the invention will emerge in the following, which describes relative preferred but non-exclusive embodiments, with reference to the appended tables of drawings, in which:
With reference to the figures, reference numeral (1) relates to a vascular access device for haemodialysis, permanently implantable in a patient having an arteriovenous fistula, (1) denotes a vascular access device for haemodialysis, (with both single and double vascular access) permanently implantable in a patient, (102) relates to a single-use device of collecting and/or injecting blood, (500) denotes a healing device for valve access, (100) a sterile package and (1000) denotes a collection and/or injection system for haemodialysis according to the invention. As can be noted from the figures, the embodiments, from the first to the third, relate to a vascular access device according to the single access invention (see
According to the invention, the single access vascular access device (1) is a vascular access device (1) made of a biocompatible and sterilisable material, and comprises:
The vascular access device (1) of the invention, of the double access type, like those illustrated in
The double access vascular access device is not only implantable in series to a blood vessel (vein, artery A and pre-existing arteriovenous fistula), but also advantageously enables carrying out the following surgical method for implanting the device which comprises following steps:
predisposing the double access vascular access device of the invention; carrying out a surgical incision on a wall of a vein (V) at an implantation site; carrying out a surgical incision on a wall of an artery (A) at an implantation site; hydraulically connecting the vein and the artery via a first conduit 222, which is hydraulically connected at the relative ends, respectively to a second conduit (233) and to a third conduit (333); fixing the relative first or second end (231, 232) of the first tubular element (202) fixed to the artery (A) at the relative surgical incision; and fixing, with the remaining of the first or second relative end (231, 232) of the first tubular element (202), which is not fixed to the artery (A) at the relative surgical incision, to the vein (V) in such a way that the first conduit (222) hydraulically connects the artery (A) to the vein (V) to constitute an artificial arteriovenous fistula (FA), arranging the second end (232) of the second tubular element (203) and the second end (332) of the third tubular element (303), the first and second plurality of through-holes (41) arranged subcutaneously in an implant skin region (7); and fixing the first and second plurality of through-holes (41) to the implant skin region (7) by means of a corresponding first and a corresponding second plurality of suture stitches (60).
With the aim of obtaining a permanent vascular access having a permanently open healed vascular access hole the applicant has also developed a healing device (500) of a vascular access, comprising:
In a relative preferred embodiment of the vascular access healing device, the relative cylinder is inclined with respect to the connection portion by an angle (A) (see respectively
With reference to
The sterile package (100) of the invention contains at least a single-use device (102) of collecting and/or injecting blood in an arteriovenous fistula constituted by:
A collection and/or injection system (1000) for haemodialysis, according to the invention, thus comprises a vascular access device (1) for haemodialysis according to the invention which can be double or single access and at least a single-use device (102) of collecting and/or injecting blood in an arteriovenous fistula (F), a vein (V) or an artery (A) constituted by:
In the case of the double access vascular access device it is preferable for the system to comprise two single access devices (102) for collecting and/or injecting.
Note that the access element and the closing means enable aspiration of any blood clots present in the access device, both single and double access. Additionally, they enable injecting an anticoagulant into the first conduit (22, 222). This anticoagulant can be heparin, for example heparin locks, sodium citrate, urokinase and mixtures thereof.
To improve the sterilisation and mechanical resistance of the vascular access device (1), it is preferably made of a metal, more preferably it is titanium, although the invention can include being constructed also using biocompatible and sterilisable plastic materials and not resorbable by the body, as described in the following. With the aim of improving the fixing of the second end (32, 232) of the second tubular element (3, 203) and the second end (332) with respect to the third tubular element (303), when present in the vascular access device for haemodialysis, to the skin region (7) for implant, the first and second plurality of through-holes (41) can be constituted by two through-holes (41), preferably arranged on the opposite side, respectively, to the second conduit (33, 232) and the conduit (333). In a case where it is constituted by three through-holes it is preferable to arrange them about the second conduit (33, 233) and the third conduit (333) at an angular distance of 120°, if a greater number of through-holes (41) is included, they can be arranged along a closed loop which surrounds the second conduit (33, 233) at the second end (32, 232) of the second tubular element (3, 203) (See
Obviously the first (2, 202) and second tubular element (3, 203) have relative longitudinal development axes (24, 34) which are incident to one another and define two angles of incidence, one supplementary to the other. This also applies to the first and third tubular element, in the case of the double access vascular access device. The preferred embodiments of the vascular access device (1) for haemodialysis are those in which the first (2) and second tubular element (3) have a relative longitudinal development axis incident to one another with a minimum angle (α) that is acute. This angle can preferably be comprised between 25° and 60°, more preferably between 25° and 50° and still more preferably between 28°-30° or 43°-48°, 25° and 45° and/or (preferably and) wherein, when the relative third tubular element (303) is present, the first tubular element (202) and third tubular element (303) have a relative longitudinal development axis incident to one another with a minimum angle (α) comprised between 25° and 50°, preferably 25°. The minimum angle (α) can advantageously be 25°, 350 or 45°. Obviously, as a function of the angle (α) the length (L2) of the second tubular element (3) measured will have to be appropriately dimensioned, obviously along the relative longitudinal development axis, in order to dimension the vascular access device (1) so 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, on the basis of the physical characteristics of the patient (gender, body type, muscle mass and fatty mass), will be perfectly able to choose a vascular access device (1) that is suitable for implanting in a patient, with the relative first tubular element (2) in series to the FAV and the second end (32) of the second tubular element (3) under the skin (7).
In an embodiment of the vascular access device (1) for haemodialysis of the invention, the first fixing means (4) can originate from the second end (32, 232) of the second tubular element (3, 203) and/or (preferably and), when present, the second fixing means (304) can originate from the second end (332) of the third tubular element (303), for example, the first and/or second fixing means (4) can be constituted by a plurality of arm braces, not illustrated, arranged spoke-fashion with respect to the second conduit (33), where each arm-band comprises one or more of the through-holes of the first plurality of through-holes (41).
It is particularly preferable for the first fixing means (4) to comprise a plate (4) having a relative main through-hole (44), wherein the first plurality of through-holes (41) is arranged peripherally with respect to the main through-hole (44), wherein the plate (4) is fixed at a relative first face to the second end (32) of the second tubular element (3, 203) so that the second conduit (33, 233) is accessible from the relative main through-hole and/or (preferably and), when present, for the second fixing means to comprise a second plate (304) having a relative main through-hole, wherein the second plurality of through-holes (41) is arranged peripherally with respect to the relative main through-hole and wherein the second further plate (304) is fixed at a relative first face to the second end (332) of the third tubular element (303) so that the third conduit (333) is accessible from the relative main through-hole (44). This simplifies the realisation of the vascular access device (1). The main through-hole (44) advantageously has the same section as the second conduit (33) at the second end and they coincide, which facilitates the insertion of the medical 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 a relative second face to the second end (45) opposite the relative first face and arranged along a plane that is parallel to the longitudinal development axis (24) of the first tubular element (2, 202) and/or (preferably and), when present, the second plate (304) is fixed to the third tubular element (303) by a relative second face (45) opposite the relative first face and arranged along a plane that is parallel to the longitudinal development axis (24, 224) of the first tubular element (2, 202). As illustrated in the embodiments of
With the aim of easily fixing the vascular access device (1) for haemodialysis, both with single and double access, when the vascular access is to be permanently implanted in series to the pre-existing FAV, to the artery (A) or to the vein (V), the first end and the second end (21, 221, 223) of the first tubular element (2, 202) can advantageously each comprise a third plurality of though-holes (28) (see
Preferably, the third plurality of through-holes (28) comprises at least 4, preferably at least 6 and more preferably at least 8. They are advantageously arranged angularly equidistant. The through-holes (41, 28) of the first and second and third plurality of though-holes must obviously have a dimension and a conformation such as to enable crossing by a surgical suture needle. During the suturing operation of the first plurality and second plurality of through-holes (28), respectively, to the skin (7) and to the two portions of the pre-existing FAV (F), of the vein (V) or the artery (A) cut by the surgeon, the surgeon will make each of the suture stitches pass through a different through-hole.
In a further fixing mode of the first and second end (21) of the first tubular element (2, 202) to the two portions of the pre-existing FAV (F), vein (V) or cut artery (A), the ends can be fixed to an end, respectively, of the first portion (51) and the second portion (52) of the pre-existing arteriovenous fistula of the vein (V) or the artery (A) using surgical glue (not illustrated).
For the purpose of improving the fixing with surgical glue of the first and/or the second end of the first tubular element (2, 202) each can comprise a relative transversal fixing sector having a relative irregular external surface, for example comprising a plurality of concavities, slots or grooves. In a preferred aspect of the invention the relative transversal fixing sector has a relative plurality of external annular grooves (29) (see
Considering the average body size of the patients, it is preferable for the vascular access device (1) for haemodialysis of the invention, single or double access, to have the following characteristics, taken alone or in combination:
It is particularly preferable, especially in the case of the double access vascular access device, for the length of the first tubular element to be 3-10 cm, more preferably 4-12 cm, 8-12 cm or advantageously 4-6 cm, both because in this way it is possible to implant it between a vein and an artery, in particular of an arm or a leg of a patient, and because in artificial conduits of this length it is possible for the same anatomic structure naturally present internally of the veins and the arteries to be recreated on the internal structure of the conduit. This significantly reduces the risk of blood clots and blocking of the first conduit (22, 222). Further, a length of the first tubular element (2, 202) of at least 4 cm, preferably 5-6 cm, ensures that the blood collected during dialysis does not contain blood just returned during dialysis. In a case where the vascular access device for haemodialysis is of the double access type, and is to be used to obtain an artificial arteriovenous fistula, the length is preferably at least 8-12 cm, which obviously depends on the patient's physical structure. Additionally, it is highly preferable for the device, or at least the inner walls of the first, second and third conduits (22, 222, 33, 233, 333), to be made of metal or biocompatible plastic materials. In the second case the device can be made by moulding or 3D printing. The preferred materials for making the device, especially if double access, are silicones, polymethyloxanes PDMSs, PTFE preferably ePTFE, DACRON, preferably silicones and/or polymethyloxanes and ePTFE, more preferably ePTFE, as they have a low propensity to thrombogenesis and enable a better endothelialisation of the relative first conduit (22, 220) which prevents the access device from becoming occluded; the risk of rejection is also reduced.
A vascular access device (1) for haemodialysis according to the invention is preferred further comprising a first valve (50) connected to the second conduit (33, 233) and configured so as, in a relative closed configuration, to hydraulically close the second conduit (33, 233) and, in a relative open configuration, to hydraulically open the second conduit (33, 233). In particular, in the case of a double access vascular access device, which therefore comprises the relative third tubular element (303), it is advantageous for it to also comprise a second valve (50) connected to the third conduit (333) and configured so as, in a relative closed configuration, to hydraulically close the third conduit (333) and so as, in a relative open configuration, to hydraulically open the third conduit (333). The presence of the first valve (50), in particular, in the case of a single access vascular access device, and of the first and second valve 50, in the case of a double access, advantageously enable limiting the blood losses once the haemodialysis has ended, improving the tolerability thereof by the patient. The valve (50) advantageously stops the blood flow as soon as the cannula of the single-use device (102) of collecting and/or injecting blood according to the invention is extracted from the first conduit or from the second conduit at the end of dialysis. In this way it is possible to minimise blood loss from the patient subjected to dialysis, in particular when the patient is medicated with a fistula pressure pad on the vascular access comprising silver as described in patent documents EP2296717 and ITBO20080303, marketed by EMODIAL S.r.l.
The first and/or second valve (50) is preferably arranged, respectively, in the second conduit (3, 33) and/or in the third conduit (333) distally of the second end of the conduits. This enables using the vascular access healing device of the invention by inserting it at the vascular access point of the body and in the second conduit and/or in the third conduit to heal the valve access about the cylinder of the healing device as mentioned in the foregoing.
The first and/or the second valve (50) is advantageously configured to enable entry into the relative conduit (3, 233, 33) through the relative second end (21, 232) of the relative tubular element (2, 203, 303) of the first end (108) of the medical cannula (103) of the single-use device (102) of collecting and/or injecting.
In alternative preferred embodiments of the vascular access device for haemodialysis with single and double access, the first valve (50) is arranged between second end (21, 232) of the second tubular element (2, 203) and the first plate (4), wherein the first plate (4) comprises, at the relative first face, first engaging means (41) engaged with the second end (21, 232) of the second tubular element (203) and/or, when the third tubular element (303) is present, the second plate (304) and the second valve (50), the second valve (50) is arranged between the second end (332) of the third tubular element (303) and the second plate (304), the second plate (304) comprising, at the relative first face, second engaging means (41) for engaging in the second end (21, 232) of the third tubular element (303) (See
In preferred embodiments of the vascular access device for haemodialysis, both single and double access, the first valve (50) is arranged on the second face of the first plate (4), opposite the relative first face and comprises third engaging means (54) for friction engagement with fourth engaging means (55) predisposed in the second end (21, 232) of the second tubular element (203) and/or in the first plate (4), and, when the third tubular element (303), the second plate (304) and the second valve (50) are present, the second valve (50) is arranged on the second face of the second plate (304), opposite the relative first face and comprises fifth engaging means (54) for friction engagement with sixth engaging means (55) predisposed in the second end (332) of the third tubular element (303) and/or in the second plate (304) (see
It is however preferable, as shown in the figures of the vascular access device for haemodialysis with single and double access, for the first valve (50) and/or the second valve (50), when present, to comprise a relative through-slot (56) which identifies two operating edges, wherein, in the relative closed configuration of the first and/or the second valve (50), the operating edges are in contact to prevent passage of fluids through the valve (50), and wherein the first and/or second valve (50) is elastically deformable to obtain the relative open configuration wherein the operating edges are moved away from one another to enable passage of a fluid through the slot (50) (see
In alternative preferred embodiments of the vascular access device for haemodialysis with single and double access, the first valve (50) has a relative perimeter and is arranged in the second conduit (33, 233) at the first end (31, 231) of the second tubular element (3, 203) with a first portion (151) of the relative perimeter fixed to the second conduit (33, 233) and with a remaining second portion (152) of the relative perimeter which is free, and which in the relative closed configuration, faces and is in contact with the second conduit (3, 233) in order to hydraulically close the second conduit and/or (preferably and), when present, the third tubular element (303), the second plate (304) and the second valve (50), the last having a relative perimeter and being arranged in the third conduit (333) at the first end (332) of the third tubular element (303) with a first portion (151) of the relative perimeter fixed to the third conduit (333) and with a remaining second portion (152) of the relative perimeter which is free, and which in the relative closed configuration, faces and is in contact with the second conduit (233) in order to hydraulically close the second conduit (233); and wherein the first and/or second valve (50) is elastically deformable to obtain the relative open configuration wherein the relative second portion of the relative perimeter is not in contact with respectively the second conduit (3, 233) and/or with the third conduit (333) to hydraulically open, respectively the second conduit (3, 233) and/or with the third conduit (333) (see
In a particularly preferred aspect of the invention the vascular access device for haemodialysis of the double access invention, which thus comprises the third tubular element (303), further comprises: a first and a second contact surface (401, 402) (See
With the aim of maximising the collection and injection velocity of blood during haemodialysis a particular preference is for both sterile packages and a collection and/or injection system (1000) for haemodialysis, according to the invention, wherein the first conduit (22) and the second conduit (33) have a relative minimum internal diameter and the cannula has a relative external diameter that is smaller by 0.2-0.3 mm than the smallest between the minimum internal diameters of the first conduit (22) and the second conduit (33). This enables, in fact, collection and/or injection of a greater blood flow.
For the purpose of maintaining sterility it is preferable that, in both the sterile package of the invention and in the collection and/or injection system for haemodialysis of the invention, the access element has a relative connection end which is: distal to the first end (108) of the medical cannula (103) and is engageable with a needle-free syringe, wherein the access element further comprises an elastically deformable element arranged in the access channel (181), and wherein the access channel (181) and the elastically deformable element are configured and mutually arranged in such a way that, when the connection end is disengaged, the elastically deformable element is not deformed and obstructs the access channel (181), in order to prevent a passage of liquids and aerosols, in such a way that, when the connection end is engaged with the needle-free syringe, the elastically deformable element is compressed by the needle-free syringe and de-obstructs the access channel (181) in order to hydraulically connect the syringe to the first end (108) of the medical cannula (103). In the package and the system the access element enables insertion of any anticoagulants into the access device, once implanted while the closing means (180) can be constituted by or can comprise a cap or lid, preferably friction-coupled, or a valve. The access element, when the first gripping means are present, can be arranged at the first gripping means (120) between the first gripping means (120) and the regulating and/or intercepting device (104) (see
To facilitate the insertion in the correct side of the first conduit (2, 202), the first end (108) of the medical cannula (103) through the second conduit (33, 203) and the first conduit (22, 222) or through the third conduit (333) and the first conduit (22, 222) of a vascular access device (1) the first conduit (22, 222) can comprise a first and/or a second protuberance (250) arranged respectively on the side opposite the second (33, 203) and third conduit (333), between, respectively, the second conduit (33, 202) and the first end (221) of the first tubular element (2, 202) and the third conduit (333), and the second end (223) of the first tubular element (202) and conformed so as to enable the first end (108) of the medical cannula (103) to pass over the protuberance and proceed respectively towards the first and second end (221, 223) of the first tubular element (202). To obtain the protuberances (250) it is possible to deform the first tubular element (202) from outside obtaining corresponding concavities (251) on the opposite side to the second and/or third tubular element (3, 202, 303) (See
The system preferably also comprises a syringe containing a pharmaceutically injectable anticoagulant liquid composition, and more preferably packaged in a syringe, advantageously a needle-free syringe.
It is understood that the foregoing is described by way of non-limiting example, and that any variants of a practical-applicational nature are taken to fall within the protective scope of the invention as described in the foregoing and as claimed in the following.
Number | Date | Country | Kind |
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102019000009318 | Jun 2019 | IT | national |
102020000013321 | Jun 2020 | IT | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/IB2020/055640 | 6/17/2020 | WO |