Patent Application
20240009438
The present invention relates generally to devices and methods that can be used for vascular access for hemodialysis. More specifically, the present invention relates to devices and methods that can be delivered percutaneously and suturelessly and that do not require an arteriovenous fistula, an arteriovenous graft, or a central venous catheter for vascular access (fistula-free hemodialysis). Further, the present invention relates to devices for improved and needleless connection of a patient to a dialyzer.
Worldwide, hemodialysis (HD) remains the prevalent dialysis modality for more than 2 million patients with end-stage renal disease. The health care expenditure to treat end-stage renal disease has increased to approximately $34 billion in 2015 in the United States alone. A significant portion of this expense is related to the establishment and maintenance of vascular access (VA) for HD [1].
The 2006 Kidney Disease Outcomes Quality Initiative (KDOQI) VA guidelines state that “options for fistula placement should be considered first.” However, more recent publications have reported 30%-60% arteriovenous fistula (AVF) nonmaturation rates for AVFs that cannot be used or require assisted maturation [2]. Although the AVF is currently considered the ideal model of VA for HD, AVFs are the source of complications, the most important being lymphedema, infection, aneurysm, stenosis, congestive heart failure, steal syndrome, hand ischemia and thrombosis. Fistula complications are associated with morbidity, mortality, and a high economic burden [6]. Several studies indicate that about 30% of HD hospitalizations are caused by VA construction and complications of vascular access [11]. Endovascular creation has simplified the creation of AVFs using either radiofrequency (everlinQ, TVA Medical, Austin, TX, USA) or thermal resistance (Ellipsys, Avenu Medical, San Juan Capistrano, CA, USA) arteriovenous anastomosis devices [1], [5]. However, many of clinical issues and complications related to AVFs, as mentioned above, have remained unaddressed.
If a patient is not a suitable candidate for AVF, arteriovenous grafts (AVG) is the second vascular access option for HD. Compared to the AVF, the AVG has better mechanical strength, earlier use, and primary failure rates but also increased risk of developing graft stenosis, a fivefold increase in infection risk, a poorer long-term patency, higher levels of complications and requires more interventions than AVF [2]. Central venous catheters (CVC) are also used in specific cases for starting hemodialysis because they provide immediate vascular access. However, prolonged CVC use results in high risk of CVC-related bloodstream infections. CVCs are also associated with a higher risk of central vein stenosis and decreased survival rates [2].
The creation of an AVF for long-term HD in 1966 by Cimino and Brescia was the first major innovation after the Scribner shunt first described in 1961 and was followed by the development of arteriovenous grafts and hemodialysis catheters. To date, the innovations in vascular access for hemodialysis have focused on arteriovenous fistulas, arteriovenous grafts, central venous catheters and the process of healthcare. Innovations related to arteriovenous fistulas have focused on: a) endovascular creation; b) (sutureless) anastomotic devices; c) maturation facilitators; and d) superificialization. Innovations related to arteriovenous grafts have focused on: a) early access AVG; b) heparin-bonded AVG; c) hybrid catheter graft; d) hybrid graft-stent; and e) tissue bioengineered vessels. Innovations related to central venous catheters have focused on: a) catheter tip design; b) catheter coating; and c) catheter lock solutions. Innovations related to the process of healthcare have focused on: a) patient-centric care; b) value versus volume-based care; c) preemptive versus reactive care; and d) evidence-based care to reduce health care-associated infections [1].
Foran [16] Clark [18] describe the use of a device, the Scribner shunt, that provides separate arterial and venous access for HD. Some of the most important benefits of the Scribner shunt are: a) the ease-of-use for repetitive HD access compared to new cannulations; and b) the ability to use the shunt for HD access immediately after implantation. Some of the limitations of the Scribner shunt were: a) the fact that the device was an extracorporeal device which lead to a higher risk of infection, in particular at the points of insertion; b) the arterial and venous indwelling segments of the devices caused thrombosis and stenosis; c) the high complexity of the surgical insertion and fixation of the cannula tip, particularly in the artery; and d) the material of the device caused clotting and progressive deterioration of the cannula function.
In U.S. Pat. No. 6,231,541 Kawamura describes a no-needle blood access device for HD comprising an artificial conduit whose opposite ends are anastomosed to a target artery or vein. The device contains a transcutaneous component that allow for connecting the subcutaneous conduit to an extracorporeal HD machine. Some of the limitations of Kawamura's disclosure are: the disclosed device requires a fistula or graft to connect a vein to an artery, the fistula/graft is created through open surgery and sutured to the target vessels; there is only one skin access point for both the arterial and venous lines for hemodialysis limiting the choice of target blood vessels and access points; the use of disclosed shutters to open and close conduits leads to blood loss when connecting a dialyzer; the long cannulas inserted in the blood stream increase the risk of infections; and once implanted, the device cannot be replaced if it fails in time.
In U.S. Pat. No. 6,719,781 Kim describes a catheter apparatus, an improved introducer system, and a methodology for creating a bypass using a prepared shape-memory alloy cuff and a graft segment in tandem as a shunt. Some of the limitations of Kim's disclosure are: the cuff is fixed to the graft by the surgeon through suturing during the procedure and the fixing means can cause tissue damage; the cuff expands based on thermal properties and needs cooling until deployment; the disclosed device can only be used for large arteries (aorta) at one end of the graft while the other end of the graft is connected surgically with sutures by the surgeon in a standard surgical procedure; and, in general, grafts cannot be connected to a dialyzer considering the conduit sizes and fluid pressures required by the hemodialysis process.
In U.S. Pat. No. 6,776,785 Yencho et al. describe a one-piece anastomosis device formed of a superelastic or pseudoelastic material which self-deforms or self-deploys from an insertion configuration to a tissue holding configuration. The self-deploying anastomosis device does not rely on a temperature transformation to achieve deployment. Some of the limitations of Yencho's disclosure are: the disclosed device can only be used to connect a tissue graft and cannot be used to connect a catheter or other semi-rigid conduit and, thus, cannot be used for hemodialysis; the risk of damaging the blood vessel is high during the deployment procedure due to the lack of maneuverability, and the device cannot be placed without direct visualization of the target vessel.
In U.S. Pat. No. 7,585,306 Abbott et al. describe anastomosis devices, tools and methods of performing sutureless anastomosis. Anastomosis devices are provided for fixing a first conduit to a second conduit in an anastomosis, where the conduits are joined by interfacing their inner walls together. Some of the limitations of Abbott's disclosure are: the devices can be used only for large blood vessels, e.g. aorta, because of the reverted graft attaching mechanism; the device cannot be connected to a catheter or other semi-rigid conduit and, thus, cannot be used for hemodialysis;
In U.S. Pat. No. 9,247,930 Coleman et al. describe devices and sutureless percutaneous methods for occluding or promoting fluid flow through openings. In an exemplary embodiment an occlusion device is provided having an outer elongated tubular body that is configured to expand and form proximal and distal wings proximate to opposed ends of the opening. The device can include a component to occlude flow through the tubular body and thus through the opening. Some of the limitations of Coleman's disclosure are: the disclosed device cannot be used to promote flow in small vessels because of the inherent wall thickness of the disclosed device structure. A device with a small outer diameter and an even smaller inner diameter cannot ensure the fluid debits required for hemodialysis, i.e., 300-600 ml/min; in addition, when promoting flow, certain disclosed device components must reside inside the target blood vessel obstructing flow in said blood vessel. Thus, the device can only be used for bypass procedure where the blood flow is already obstructed in the target vessel. Moreover, the disclosed device is made of a solid stainless steel structure that is too heavy to attach to small vein walls that would collapse under the device weight.
In U.S. Pat. No. 9,597,443 Yevzlin et al. describe an anastomotic connector comprising a tubular access port and an anchor with a plurality of fingers to be extended in a blood vessel connected to the tubular access port. Some of the limitations of Yevzlin's disclosure are: the disclosure does not allow for percutaneous deployment of a catheter pre-connected to the disclosed anastomotic connector thus limiting the choice of anastomosis locations to those directly accessible by open surgery; the proximal end of the anastomotic connector that resides outside the blood vessel is fixed in shape and perpendicular to the longitudinal axis of the blood vessel, said characteristics further limiting the maneuverability of the device and the ability to connect it to smaller blood vessels.
What is needed are improved devices and methods for vascular access for hemodialysis that reduce the risks associated with establishing and maintaining vascular access, decrease time to first use, increase long-term patency, minimize complications, simplify the hemodialysis procedure, and reduce the burden on patients and on the healthcare system.
Devices and methods for fistula-free vascular access for hemodialysis are disclosed herein. In exemplary embodiments, devices are provided including a transcutaneous access port for needlelessly connecting a patient to a dialyzer, an intracorporeal conduit providing a fluid path between said transcutaneous port and a blood vessel, and a device anchor, said device anchor permitting the sutureless anastomosis of said intracorporeal conduit to said blood vessel. In exemplary embodiments, methods are provided for creating fistula-free vascular access for hemodialysis and performing hemodialysis procedures without needle punctures.
In one exemplary embodiment, an implantable transcutaneous access port disclosed herein comprises a port body with an inner lumen and a subcutaneous segment attachable to an intracorporeal conduit, wherein the longitudinal axis of said subcutaneous segment and the longitudinal axis of said port body are at a variable angle with respect to each other in order to adapt to the anatomy of the access and implant locations and wherein said inner lumen has different profiles such as to provide variable blood flow characteristics adapted to either arterial or venous blood flow and, wherein the port body can be connected to an extracorporeal connector and to a dialyzer.
In one exemplary embodiment, an intracorporeal conduit disclosed herein comprises a distal more rigid segment and a proximal less rigid segment, said proximal less rigid segment being attached to a transcutaneous access port and said distal more rigid segment being fixedly attached to and within a tubular device anchor, wherein said distal more rigid segment extends through the inner lumen of said device anchor such that the distal end of said segment and the distal end of said device anchor are flush, and wherein the outer diameter of said distal more rigid segment of said conduit is equal to or slightly smaller than the inner diameter of said device anchor.
In one exemplary embodiment, a device anchor disclosed herein for suturelessly anastomosing the distal end of an intracorporeal conduit to a blood vessel or graft comprises a tubular body with a pre-shaped self-expandable proximal segment, a pre-shaped self-expandable waist segment, and a pre-shaped self-expandable distal segment, wherein said proximal segment self-expands outside a wall of said blood vessel or graft, the length of the said waist segment is approximately the size of the thickness of said wall and said distal segment self-expands inside said blood vessel or graft or inside a tubular device implanted in the blood vessel or graft as to, together with the self-expanded proximal segment, apply sufficient pressure on the vessel wall in order to keep said device steadily attached to said wall without penetrating it, wherein the proximal end of said device anchor slides freely over said distal more rigid segment of said intracorporeal conduit during compression of said device anchor and during self-expansion of said device anchor from a compressed configuration to its pre-shaped expanded configuration, and wherein said device anchor comprises, at its proximal end, an attaching and detaching mechanism for the attachment and detachment of a delivery element for the percutaneous deployment of said device.
In one exemplary embodiment, a fistula-free hemodialysis method disclosed herein consists of percutaneously deploying a first said intracorporeal conduit and anastomosing it to an artery for creating arterial access and a second said intracorporeal conduit and anastomosing it to a vein for creating venous access and independently connecting each of said devices respectively to the arterial and venous lines of said dialyzer using said transcutaneous ports.
The contributions of the present invention in addressing current hemodialysis needs with respect to prior art are manyfold. The devices disclosed in the present invention can be delivered percutaneously and without employing sutures and provide independent access to arteries and veins. The methods disclosed herein allow for the creation of fistula-free vascular access for hemodialysis without the need for an arteriovenous fistula, arteriovenous graft or central venous catheter. Thus, the risks and issues associated with the creation and maintenance of vascular access for hemodialysis are significantly reduced. Moreover, the devices disclosed herein provide access for required hemodialysis debits of 300-600 ml/min to and from blood vessels as small as 2-3 mm in diameter, thus increasing the number of choices for vascular access points in a patient's vasculature. Further, the devices and methods disclosed herein allow for a needleless connection between a patient and a dialyzer, thus simplifying and decreasing the burden of the hemodialysis procedure in hospitals and homecare settings.
While the invention is described herein in detail with reference to the preferred embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made and equivalents employed, without departing from the present invention. Further, a person skilled in the art will appreciate that the devices disclosed herein can be adapted for use in any of the methods disclosed herein, and likewise, the methods disclosed herein can be adapted for use in conjunction with any of the devices disclosed herein. In order to streamline the disclosure of the present invention, not all elements of one embodiment are described in detail but only those specifically targeted in that particular embodiment. For example, an embodiment may be illustrated comprising a valve and another without a valve. It will be apparent to one skilled in the art that such elements, like the above mentioned valve, may be or not be present in all configurations and drawings without affecting the objective, spirit, and scope of the present invention. In addition, modifications may be made to adapt a particular situation, material, shape, dimension, processor, or method to the objective, spirit, and scope of the present invention. All such modifications are intended to be within the scope of the claims appended hereto. In the present disclosure, like-numbered components of embodiments generally have similar features, and thus within a particular embodiment each feature of like-numbered component is not necessarily fully elaborated upon in the description of the particular embodiment.
A second intracorporeal conduit 180 is deployed percutaneously through a skin area 135 and attached to the wall of a conduit in the body, e.g., to the wall of a blood vessel or graft 105 using the device anchor 150 as described further herein. In one embodiment of the present invention blood vessel 105 is a vein. In one embodiment of the present invention, conduit 180 is attached to transcutaneous port 130 in order to facilitate the connection of conduit 180 to an external device using conduit 165 and connector 160. In one embodiment of the present invention, transcutaneous access port 130 is attached to the patient's skin. In one embodiment of the present invention, conduit 165 can be attached to and detached from transcutaneous access port 130. In one embodiment of the present invention, connector 160 is attached to the venous line of a hemodialysis machine (dialyzer) and blood can be infused (returned) (167) into vein 105 from the dialyzer during the hemodialysis procedure.
In another embodiment of the present invention, a first and a second intracorporeal conduits can be attached (anastomosed) at different locations on the same conduit in the body, e.g., on the same vein or a graft.
In another embodiment of the present invention, only one intracorporeal conduit and transcutaneous port is deployed, e.g., to a vein or graft for single needle hemodialysis.
According to one embodiment of the present invention, the port body 280 is connected to the implanted intracorporeal conduit 205 by pushing the conduit 205 into the segment 215 of the port body. In another embodiment of the present invention, the conduit 205 can be pushed over the segment 215 of the port body. In another embodiment of the present invention, the conduit 205 and the inner wall of the segment 215 are made with matching threads 208, such that conduit 205 can be threaded into the segment 215. In one embodiment of the present invention, the conduit 205 is pushed or threaded into the segment 215 up to a stop 220. The width of stop 220 matches the wall size of conduit 205 such that the inner lumen presents no obstacle to the flow through the conduit and laminar flow is ensured. After inserting the conduit 205 into or over segment 215 of the port body, a band or ring 210 is deployed to additionally secure in place the connection between the conduit 205 and the port body segment 215.
In one embodiment of the present invention, the inner lumen 282 contains valve 212. In one embodiment if the present invention, valve 212 is a 3-way valve, infusion, aspiration, and closed, 213. In another embodiment of the present invention, the valve 212 only opens when pushed by the tip of an access device, e.g., a syringe, when said access device is inserted into the lumen of said port.
Port body 280 and port segments 215, 222 and 230 can be made of any suitable, biocompatible material, such as stainless steel, titanium, alloys, silicone, polymers e.g., polyurethanes, PTFE, lightweight polysulphone or of any combination of the above.
In one embodiment of the present invention, port 200 can be printed using multi-material 3D and 4D printing technologies.
Walls 222 and 230 of port 200 are shaped and made of a material and processed such as to ensure smooth liquid flow with minimal wall friction and minimal turbulence. The size of the angle 225 between the longitudinal axis of conduit 205 and the longitudinal axis of said port body can be chosen depending on the location of implantation of the port and of the preferred direction of the conduit 205, for example relative to skin surface. Further, angle 225 can be chosen as a function of the technique used (tunneled or not) and of the desired location of skin access.
In one embodiment of the present invention, port 200 is attached to the skin at the location of implantation using an auto-adhesive layer 260, for example using a hydrocolloid acrylic adhesive. In one embodiment of the present invention, the auto-adhesive provides antimicrobial protection with integrated chlorhexidine gluconate (CHG). After placement, port 200 can be additionally secured in place with sutures to the skin through the port holes 270 provided in the port body for this purpose. In one embodiment of the present invention, the sutures are absorbable or are removed once the self-adhesive layer 260 is safely secured to the skin.
In one embodiment of the present invention, implantable medical mesh 285 is attached to the body 280 of transcutaneous port 200. Such a mesh bag provides additional anchoring means adapted for tissue ingrowth, tissue encapsulation or tissue adhesion and ensures greater stability and additional protection of the implanted port. In another embodiment of the present invention, the exterior surface of port body 280 is made of such material and processed in such a way as to ensure the additional anchoring means through tissue integration mentioned above.
In one embodiment of the present invention, a protective cap 250 can be attached to body 280 of the transcutaneous port while the port is not in use. In one embodiment of the present invention, the cap is attached (screwed) and detached (unscrewed) by rotation 265 using the threads 290 in port body 280 and the matching threads 275 of cap 250. In one embodiment of the present invention, the connection at level 240 between cap 250 and body 280 is sealed using matching seals 245. The seal 245 can be made of different materials, e.g., rubber or silicone. Seal 245 can also be made of different polymers in a matching pair with the seal 235 inside the wall of the body 280. According to the present invention a matching male-female profile between the seal 245 and the seal 235 is preferably used that prevents fluid from flowing out of the conduit 282 when the cap is attached to the port body. In one embodiment of the present invention, such profile consists of concentric shapes on the seals 245 and 235 that allow the male portion of the profile situated on seal 245 to enter a groove on seal 235, while cap 250 is rotated for closure.
In one embodiment of the present invention, protective cap 250 has a safety mechanism to prevent accidental opening. In one embodiment of the present invention the safety mechanism is an anti-rotation lock 257. To unlock the cap, the lateral push-to-rotate 255 fixtures are used. Other anti-rotation locks can also be used: down-push and rotate, alignment of cap and body to a certain unique position, an external lock that needs to be pushed to release the cap for rotation, or an external lock or key of a shape that only matches a corresponding shape imprinted in the cap.
In one embodiment of the present invention, protective cap 250 is color coded. In one embodiment of the present invention, the surface 251 of the cap 250 can be red to indicated that the port is used to access an artery in the patient's body. In another embodiment, the cap surface 251 of the cap 250 can be blue to indicate that the port is used to access a vein in the patient's body.
In one embodiment of the present invention, protective cap 250 is sterile and single use.
In one embodiment of the present invention, protective cap 250 can be made of any suitable material such as silicone, rubber, or polymers (e.g., polyurethanes, PTFE) or a combination of the above. Stainless steel or alloys like nitinol can be used for the seal 245 or for providing any required reinforcements.
In one embodiment of the present invention, a patch or gel pad 298 is applied over cap and over the surrounding skin to provide additional barrier to microbes and external contaminants and to reduce port colonization and CRSBI (catheter related blood stream infections). In a preferred method of use, patch 298 is to be replaced with each use of the transcutaneous port together with cap 250.
In one embodiment of the present invention, transcutaneous port 200 provides variable blood flow characteristics in order to accommodate either arterial or venous flow. In one embodiment of the present invention, inner lumen 282 has a smaller diameter at its distal end compared to a larger diameter at its proximal end in order to increase the pressure of fluid infusion into conduit 205 or to decrease the pressure of fluid aspiration from conduit 205. In another embodiment of the present invention, inner lumen 282 has a larger diameter at its distal end compared to a smaller diameter at its proximal end in order to decrease the pressure of fluid infusion into conduit 205 or to increase the pressure of fluid aspiration from conduit 205.
In one embodiment of the present invention, transcutaneous port 200 can be detached from the conduit 205 and from the skin 202 and can be replaced with another port 200 or with any other port connectable to conduit 205.
In one embodiment of the present invention, distal segment 315 self-expands in the lumen of a conduit, e.g. a blood vessel or graft and abuts the conduit wall from the inside of the conduit. In one embodiment of the present invention, proximal segment 320 self-expands outside the conduit and abuts said conduit wall from the outside of the conduit. In one embodiment of the present invention, waist segment 317 has a width approximately equal to the thickness of the blood vessel or graft wall, connects said distal 315 and proximal 320 segments of the device and ensures that the distal and proximal segments are applying the appropriate amount of pressure to said conduit wall as to keep the device steady on the conduit wall.
In one embodiment of the present invention, the proximal segment 320 is larger in size than the distal segment 315 in order to provide a larger footprint outside the blood vessel and a smaller footprint inside the blood vessel. The larger footprint outside the blood vessel provides better protection and more reliable attachment to the blood vessel. The smaller footprint inside the blood vessel reduces turbulences in flow and the risks associated with thrombosis and vessel wall damage, e.g., stenosis.
Distal segment 315 and proximal segment 320 of device 300 can be made of medical-grade stainless steel or of cobalt alloy or of a shape memory alloy, e.g., nitinol or of other shape memory materials, such as shape memory polymers, or of other superelastic material.
In one embodiment of the present invention, said distal and proximal segments, as well as the waist segment, are appropriately sized pieces of alloy fabric. One can solder, braze, weld or otherwise affix the ends of the braided alloy fabric to a distal ring 310, to waist 317, if the case, and to a proximal ring 325.
In one embodiment of the present invention, said distal and proximal segments are laser cut struts in a tube of shape memory material and pre-shaped or preprogrammed in the desired configuration as described further herein. In one embodiment of the present invention, said device is formed by laser cutting patterns in shape memory material tubing or sheets that are subsequently rolled into cylinders whose edges are welded together.
In one embodiment of this invention, the wall thickness 308 of the tubular device structure is in the range of 0.1 mm in order to allow for deployment in small peripheral blood vessels. In another embodiment of the present invention, each or all of the said segments of the device 300 or device 300 in its entirety can be printed using multi-material 3D and 4D printing technologies.
In one embodiment of the present invention, distal segment 315 is drug coated in order to minimize the damage to the vessel wall and prevent stenosis and thrombosis, e.g., with paclitaxel or sirolimus. In another embodiment of the present invention, said distal segment is gold plated in order to lower thrombogenicity.
In one embodiment of the present invention, attachment segment 327 is used to attach a delivery element to device 300 according to the present invention. In one embodiment of the present invention, a delivery element is attached to device 300 by screwing it onto the attachment threads 327 and is detached from the said device by unscrewing it. In another embodiment of the present invention, the attachment mechanism 327 can be a “bayonet” lock.
In one embodiment of the present invention, attachment segment 330 is used to attach device 300 to the distal end of a conduit, e.g., arteriovenous graft or arteriovenous shunt. In one embodiment of the present invention the conduit is attached to the device 300 by force pushing the end of the conduit over the attachment segment and securing it in place using heat shrink tubing. In another embodiment of the present invention, attachment mechanism 330 can be a “bayonet” lock or a threaded screw-unscrew attachment. In another embodiment of the present invention, attachment mechanism 330 can be made to match an appropriate segment of the graft or shunt end to which it is connected.
In one embodiment of the present invention, attachment segments 327 and 330 can be made of the same material as the any of the other segments of device 300 or of stainless steel, silicone, PTFE, polyurethane or of any other suitable biocompatible material.
In one embodiment of the present invention, device anchor 300 can have a circular cross-section. In another embodiment of the present invention, the device anchor 300 can have an elliptical cross-section, in which case the longer axis of such ellipsis must be aligned with the longitudinal axis of the target conduit.
In one embodiment of the present invention, the inner cross-section of the device 300 is of such size as to ensure the appropriate debit of fluid required for a hemodialysis procedure, e.g., in the range of 300-600 ml/sec.
In one embodiment of the present invention, device 300 or at least one of its segments is radiopaque and/or echogenic. In one embodiment of the present invention, device 300 is MRI compatible, power injectable and Latex, DEHP and PVC free. In one embodiment of the present invention, device 300 is marked such as to allow an easy deployment under ultrasound guidance and an easy alignment along the blood vessel in the case of an elliptical embodiment.
In one embodiment of the present invention, the conduit 404 comprises a 3-way (infusion, aspiration, and closed) valve, as illustrated at 620 on
In one embodiment of the present invention, the device can be built in different sizes, such as to allow deployment in larger vessel, e.g., in the range of 6 mm in diameter in the upper arm or upper legs and in smaller vessels, for example in blood vessels in the range of 2 mm diameter corresponding to arteries and veins of the lower arm or lower leg. Further, the sizes of the device are such as to allow deployment at deeper depths, e.g., in the range of 6 cm in the upper arm and leg and at shallower depths, for example in the range of 2 cm in the lower arm and leg.
In one embodiment of the present invention, after the percutaneous deployment and attachment of device 400 to the wall of a blood vessel or graft as further described herein, the proximal end of conduit 404 remains out of the patient's body such that it can be connected to another device, as described further herein. In one embodiment of the present invention the said conduit is trimmable and marked with cm markings.
In one embodiment of the present invention, conduit 404 is made of two segments 430 and 435 of different materials with different properties. In one embodiment of the present invention, segment 430 extends from the distal end of the conduit (and of anchor 300) for a minimal length equal to the length of anchor 300 when said anchor is in a compressed (non-expanded) configuration as illustrated and described in
In one embodiment of the present invention, segment 430 is made of such material as to be more rigid than segment 435 in order to allow for the proximal segment of anchor 300 to easily slide over said more rigid segment 430 during the deployment of the device. In one embodiment of the present invention, segment 430 is made of such material as to allow for reliable attachment of anchor 300 to conduit segment 430 at their respective distal ends. In one embodiment of the present invention, segment 430 can be made of silicone, PTFE, polyurethane or similar materials of different rigidity than segment 435 and/or braided with braids made of stainless steel or nitinol or similar alloys. In one embodiment of the present invention, segment 430 is made of titanium in order to minimize blood clotting. In one embodiment of the present invention, segment 430 is gold plated in order to lower thrombogenicity. Segments 430 and 435 can be attached together using heat shrink tubing, overmolding or co-extrusion, by using an attachment mechanism 330, by pushing segment 435 over or into segment 430 or segment 430 can be made by additionally braiding and hardening segment 435.
In one embodiment of the present invention, the ratio between the outer diameter of said device anchor 300 in a compressed (non-expanded) configuration and the inner diameter of the more rigid distal segment 430 of conduit 404 is minimized by minimizing the wall thickness of said device anchor and the wall thickness of said more rigid distal segment such as to allow for fluid debits required for hemodialysis in the range of 300-600 ml/min while allowing attachment to small peripheral veins and arteries in the range of 2-3 mm in diameter.
In one embodiment of the present invention, segment 435 extends from the proximal end 432 of segment 430 to the proximal end of conduit 404 outside the patient's body. In one embodiment of the present invention, segment 435 is made of silicone, PTFE, polyurethane, or similar materials.
In one embodiment of the present invention, device 400 can be removed from the vessel wall and from the patient's body percutaneously through a procedural sheath according to the present invention. The opening left in the vessel wall after removal can be closed through the procedural sheath or over a guidewire using a standard vessel closure device. In one embodiment of the present invention, a method for percutaneously removing said device from the wall of a blood vessel comprises the following steps:
In one embodiment of the present invention, the 3-way (622) (infusion, aspiration, and closed) valve 620 minimizes risk of conduit blockage due to thrombosis by allowing infusion and aspiration of fluid to and from target conduit 602 through device conduit 404 only upon demand and by preventing fluid, e.g., blood from entering conduit 404 when the device is not used for infusion or aspiration.
In one embodiment of the present invention, device anchor 705 is a thin walled cylindrical structure, wherein the distal, waist and proximal segments of said device are formed using a shape memory material, said distal and proximal segments consisting of several longitudinal struts disposed around the circumference of said cylindrical structure, said waist segment being ring-shaped, wherein said longitudinal struts of said proximal segment are attached at their distal end to said waist ring, wherein said longitudinal struts of said proximal segment are attached to a second ring at their proximal end, wherein said longitudinal struts of said distal segment are attached at their proximal end to said waist ring, wherein the distal and the proximal segments have the same or a different number of struts and, wherein the struts have the same or different widths, and wherein the struts are disposed equidistantly or at variable distance from each other around the circumference of said cylindrical structure 820.
In one embodiment of the present invention, said struts of said distal and proximal segments are pre-shaped through shape setting in their radially expanded and longitudinally compressed configuration, wherein each longitudinal struts of the proximal segment is bent outwardly as to be set in a V or U-shape, wherein the two ends of each of the V or U-shaped struts are attached to the proximal ring and to the waist ring respectively.
In one embodiment of the present invention, said struts of said proximal segment are coupled to each other by structures extending generally laterally.
In one embodiment of the present invention, the distal segment of said device comprises a plurality of struts forming a net-like structure 1030 that, when pre-shaped, expands radially and compresses longitudinally.
In one embodiment of the present invention, the delivery sheath 2003 can be connected at its proximal end to a hemostasis valve 2170. In such case, the male-to-male luer connector 2090 connects the female luer connector 2020 of loader 2030 to the female luer connector of hemostasis valve 2170 and device 400 is transferred from loader 2030 to delivery sheath 2003 through the connector 2090 and through the hemostasis valve.
In one embodiment of the present invention, delivery element 2080 is a tubular structure, with an attachment mechanism at its distal end that can be attached to the matching attaching mechanism 327 of device 400. The delivery element is made of such materials as to be flexible enough and to provide enough torque and push/pull strength in order to allow for the use described herein.
The loader 2030, delivery element 2080, and the delivery sheath 2003 can be made of materials such as silicone, PTFE, polyurethane or other similar materials. In a preferred embodiment according to the present invention, loader 2030 is transparent in order to be able to visualize that device 400 is properly loaded.
In one embodiment of the present invention, loader 2030, delivery element 2080, and/or delivery sheath 2003 can be made using 3D and 4D printing of appropriate biocompatible materials.
In one embodiment of the present invention, a method of loading the device 400 into loader 2030 and deploying it in a blood vessel through a delivery sheath 2003 consists of the following steps:
In another embodiment of the present invention, steps 5, 6, and 7 of the above described method of loading the device 400 into loader 2030 and deploying it in a blood vessel through a delivery sheath 2003 are replaced by the following steps:
In order to gain access to the target blood vessel, a guidewire 2290 with an atraumatic tip 2292 has been introduced in the blood vessel 602 through an insertion needle penetrating the tissue 607 and the vessel wall 605. The insertion needle was retracted to leave distal end 2292 of guidewire 2290 in the blood vessel while the proximal end of guidewire 2290 remained outside the patient's skin 2210. Dilator/introducer 2115 was introduced in the blood vessel over the guide wire 2290 in order to enlarge hole 2208 in the blood vessel wall 605 and to facilitate the introducing of delivery sheath 2003 containing device 400.
In one embodiment of the present invention, in order to access blood vessels of small size, e.g., 2 mm in diameter, distal end 2235 of delivery sheath 2003 and the distal end 310 of device 400 need to be placed flush and flush with the inner wall of blood vessel 605. Thus, the space required for the deployment of the distal anchor segment 315 can be maximized. Flush alignment is verified during the placement procedure using the blood flow back channel 2117 present in the wall of the dilator/introducer 2115. To flush the distal tip of the device with the blood vessel wall, the ensemble consisting of procedural sheath 2003, device 400, and dilator/introducer 2115 is slowly advanced along the guide wire 2290 until control blood flow comes out through blood flow back channel 2117 and is visible at the proximal end of said channel 2117 outside the patient's skin. The correct alignment of the device at the vessel wall can be checked by ultrasound imaging using the echogenic markers of delivery sheath 2003 and/or of device 400.
In one embodiment of the present invention, in order to maximize blood flow through the device, the deployment of devices of larger sizes than the inner diameter of the targeted blood vessel is achieved by using device having an elliptic cross-section. In such a case, the long axis of the device's elliptical cross-section must be aligned with along the blood vessel, i.e., aligned with the longitudinal axis of the blood vessel. Enhanced ultrasound reflective markers and/or radiopaque markers integrated on the device 400 and/or on delivery sheath 2003 can be used to allow for longitudinal alignment using ultrasound and/or X-ray imaging guidance. Furthermore, a standard dilation of the target blood vessel can be performed if necessary during device deployment to enhance maneuverability of the device.
In one embodiment of a hemodialysis method according to the present invention, a first intracorporeal conduit 205 connected to a first port 200 is anastomosed to a vein and a second intracorporeal conduit 205 connected to a second port 200 is anastomosed to an artery. A first extracorporeal connector 2300 connected to the first venous access port 200 is connected to the venous line of a dialyzer and a second extracorporeal connector 2300 connected to the second arterial access port 200 is connected to the arterial line of a dialyzer. In one embodiment of the present invention, one or more elements of the connectors 2300 are color coded in blue as to identify venous line access and connection and in red as to identify arterial line access and connection. When the transcutaneous port 200 is in use, i.e., when connected to an extracorporeal connector 2300, the patch 298 and the cap 250 have been removed and replaced by the body 2302 of the extracorporeal connector 2300.
The conduit 2385 is connected to the element 2340 of the connector body 2302 through the connecting segment 2350. Depending on the materials of the conduit wall 2345 and of the body element 2340, connecting segment 2350 can be made using different technologies and materials, e.g., stainless steel, titanium, alloys, silicone, polymers e.g., polyurethanes, PTFE, lightweight polysulphone or of any combination of the above. In one embodiment of the present invention, conduit 2385 is glued to connector body element 2340.
In one embodiment of the present invention, element 2340 of the connector body is attached and removed to and from port 200 by rotating (2330) and pushing (2325) a push-rotate locking mechanism 2335. The safety mechanism 2335 that prevents accidental disengagement of the element 2340 matches the safety mechanism of port 200. In one embodiment of the present invention, safety mechanism 2335 is lateral-push-to-rotate anti-rotation lock. Other anti-rotation locks can also be used: down-push and rotate, alignment of cap and body to a certain unique position, or an external lock that needs to be pushed to release the cap for rotation.
The extracorporeal connector 2300 can be made of any suitable material such as silicone or polymers (e.g., polyurethanes, PTFE) or a combination of the above. Stainless steel or alloys like nitinol can be used for braiding the conduit 2385, for the seals 2360 and 235 or for providing any required reinforcements. Rubber or lightweight polysulphone can be used for the element 2340 of the body 200.
In one embodiment of the present invention, valve 212 is a 3-way valve 213 (closed, infusion, aspiration) that is normally closed and opens only under the negative pressure (aspiration) or positive pressure (infusion) generated by the device or dialyzer attached to connector 2395.
In one embodiment of the present invention, valve 212 is normally closed and opens only when the distal end of the extracorporeal connector 2300 is attached to the connector body 2302 such that the distal end of said connector pushes through valve 212 and opens it.
In one embodiment of the present invention, the extracorporeal connector 2300 is sterile and single use.
In one embodiment of the present invention, adaptor 2510 is provided in different configurations as illustrated by 2550 and 2560 with channels or buttonholes 2520 having different locations for each configuration such that, when a different configuration is used, the access points on skin for needle puncture change locations. Thus, the skin is not punctured in the same location each time giving the skin time to heal from one puncture to the next, e.g., from one hemodialysis session to the next. Furthermore, each configuration of adaptor 2510 can have one or several access channels and an appropriate size corresponding to the number and location of the access channels.
In one embodiment of the present invention, adaptor 2510 is made of any suitable, biocompatible material, such as stainless steel, titanium, alloys, silicone, polymers e.g., polyurethanes, PTFE, lightweight polysulphone or of any combination of the above. For example, the body of adaptor 2510 can be made of polymers overmolded over channels 2520 made of stainless steel, titanium, or nitinol.
In the foregoing detailed description, various individual features are grouped together in order to streamline the disclosure. However, inventive subject matter also lies in such individual features and not only in their grouping together as disclosed in the foregoing embodiments. Thus, the following claims are hereby incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained herein.
This application is a division of PCT Application No. PCT/EP2022/057987 filed on 25 Mar. 2022, International Publication Number WO 2022/207505 A2 and claims priorities to: 1. U.S. Provisional Patent Application Ser. No. US 63/167,771 filed on Mar. 30, 2021 (Needleless transcutaneous port)2. U.S. Provisional Patent Application Ser. No. US63/168,276, filed on Mar. 31, 2021 (Anastomosis device and method for percutaneous delivery thereof)3. U.S. Provisional Patent Application Ser. No. US63/168,277, filed on Mar. 31, 2021 (Devices and methods for Hemodialysis)4. U.S. Provisional Patent Application Ser. No. US 63/222,062, filed on Jul. 15, 2021 (Devices and methods for sutureless anastomosis) the disclosures of which are incorporated herein by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63167771 | Mar 2021 | US | |
| 63168276 | Mar 2021 | US | |
| 63168277 | Mar 2021 | US | |
| 63222062 | Jul 2021 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/EP2022/057987 | Mar 2022 | US |
| Child | 18237916 | US |
