Patent Application
20250222241
Generally, this application relates to shunts for cerebrospinal fluid (CSF).
The foregoing summary, as well as the following detailed description of certain techniques of the present application, will be better understood when read in conjunction with the appended drawings. For the purposes of illustration, certain techniques are shown in the drawings. It should be understood, however, that the claims are not limited to the arrangements and instrumentality shown in the attached drawings. Furthermore, the appearance shown in the drawings is one of many ornamental appearances that can be employed to achieve the stated functions of the system.
According to embodiments, a CSF shunt includes: an inlet configured to receive CSF from a spinal intradural space in a patient; a shunt body with a sidewall and a lumen within the sidewall, wherein the shunt body is configured to extend through an interstitial space and a vein wall, wherein the lumen is in fluid communication with the inlet; and a regulator outside of the lumen, wherein the regulator is configured to regulate a flow of the CSF from the inlet by passing a regulated portion of the CSF from the lumen and into a venous system of the patient. The regulator may be a slit regulator in the sidewall of the shunt body. The sidewall of the shunt body may include a first region including a first material and a second region including a second material; at least one of the first material has a lower durometer than the second material, or the first region has a smaller inner diameter than the inner diameter of the second region; the regulator is in the first region; and no regulator is in the second region. The first material may have a lower durometer than the second material. The regulator may include a non-stick material. The first region may have a smaller inner diameter than the inner diameter of the second region. The first material may have a lower durometer than the second material and the first region has a smaller inner diameter than inner diameter of the second region. The regulator may include a first regulator and a second regulator; the sidewall of the shunt body may include a first region including a first material and a second region including a second material; at least one of the first material may have a lower durometer than the second material, or the first region has a smaller inner diameter than the inner diameter of the second region; the first regulator may be in the first region; and the second regulator may be in the second region. The first material may have a lower durometer than the second material. The first regulator and the second regulator may include a non-stick material. The first region may have a smaller inner diameter than the inner diameter of the second region. The first material may have a lower durometer than the second material and the first region may have a smaller inner diameter than the inner diameter of the second region. The first regulator and the second regulator may regulate differently from each other. The regulator may include at least one discontinuity in the sidewall of the shunt body and a sleeve exterior to an outer surface of the sidewall of the shunt body, wherein the sleeve overlaps the at least one discontinuity. The sleeve may include an end coupled to the shunt body and an end at least partially not coupled to the shunt body. The end at least partially not coupled to the shunt body may be entirely not coupled to the shunt body. The sleeve may include at least one discontinuity.
According to embodiments, a CSF shunt includes: an inlet configured to receive CSF from a spinal intradural space in a patient; an outlet configured to provide the CSF into a venous system in the patient; a shunt body with a sidewall and a lumen within the sidewall, wherein the shunt body is configured to extend through an interstitial space and a vein wall, wherein the lumen is in fluid communication with the inlet and the outlet, such that a flow of the CSF flows between the inlet and the outlet; and a regulator configured to vary at least one of the size or the shape of the outlet to regulate the flow of the CSF fluid. The shunt body may include a first region including a material having a first durometer and a second region including a material having a second durometer less than the first durometer; and the outlet may be formed at least partially by the second region.
According to embodiments, a CSF shunt includes: an inlet configured to receive CSF from a spinal intradural space in a patient; an outlet configured to provide the CSF into a venous system in the patient; a shunt body with a sidewall and a lumen within the sidewall, wherein the shunt body is configured to extend through an interstitial space and a vein wall, wherein the lumen is in fluid communication with the inlet and the outlet, such that a flow of the CSF flows between the inlet and the outlet; and a constrictor positioned outside of the shunt body, wherein an inner diameter of the constrictor is less than an outer diameter of the shunt body, wherein the constrictor is elastic and regulates the flow of the CSF.
Embodiments herein relate to systems and methods for draining excess CSF from a patient's subarachnoid space, and particularly the subarachnoid space in the thecal sac of the spinal canal. Such CSF shunts and deployment techniques are described in U.S. Prov. No. 63/446,064, filed on Feb. 16, 2023, and U.S. Ser. No. 18/443,455, filed on Feb. 16, 2024, the entireties of which are incorporated by reference, herein. Embodiments herein describe CSF shunts with flow regulation features. CSF shunts are described, but the principles may be applicable to other types of shunts, such as interatrial/interventricular shunts, pulmonary artery shunts, or other arterial/venous shunts.
Cerebrospinal fluid is an ultrafiltrate of blood plasma. It is a substantially clear liquid with a density close to that of water. The CSF bathes the brain inside the skull as well as the spine and spinal nerve roots inside the spinal canal. The CSF is enclosed within the dura mater or dura, which is a thick and relatively inelastic membrane covering the inner surface of the skull and spinal canal. In the spinal area the dura is called the thecal sac. The CSF is secreted inside the brain ventricles by the choroid plexus, and it circulates around the folds of the brain and around the spinal cord and nerve roots. The CSF is reabsorbed into the venous blood by the arachnoid granulations. Some arachnoid granulations are located around the brain along the walls of the venous sinuses, in which case the CSF transits into the venous sinuses. Other arachnoid granulations are located along the nerve roots of the spinal canal, in which case the CSF transits into the veins surrounding the nerve roots.
Hydrocephalus is a relatively neurological disease in which, for various reasons, the pressure of the CSF increases. Hydrocephalus can be communicating, where the CSF flow pathway is not interrupted but there is a deficit of the reabsorption of CSF by the arachnoid granulations. Hydrocephalus can also be caused by overproduction of CSF. Hydrocephalus can be secondary to an obstacle to the CSF circulation, which is called non-communicating hydrocephalus. Some hydrocephalus conditions are congenital, while others may be acquired (for example, after subarachnoid hemorrhage).
One approach to treating hydrocephalus is by diverting CSF. CSF diversion is commonly known as shunting and refers to the placement of a permanently (or semi-permanently) implanted shunt (e.g., a tube) that diverts CSF from the subarachnoid space to another area of the body where it can be reabsorbed. This surgery may be performed by neurosurgeons.
In addition to hydrocephalus, there are other diseases that also be treated by CSF diversion using the techniques described herein. For example, in some patients, brain ventricles may be contracted, resulting from a disease such as idiopathic intracranial hypertension (IIH). In some patients, ventricles may be enlarged while CSF pressure has not increased, resulting in a disease such as normal pressure hydrocephalus (NPH).
Conventional shunts may access the CSF via locations in the skull. However, the neurosurgery required to implant such shunts may be relatively risky. For example, when a shunt is to be positioned in an inferior petrosal sinus, such a procedure may have high risks and a failure could lead to a neurological complication or even death. Embodiments disclosed herein describe a delivery system and CSF shunt for placement outside of the cranial cavity. Particularly, embodiments herein disclose placing a CSF shunt in the spinal canal—e.g., in the lumbar region. The lumbar region includes multiple sites that can be accessed via endovenous catheters guided by X-ray fluoroscopy to deliver and position the CSF shunt. The spinal region (e.g., lumbar region) may be a safer region to operate on and present lower risk, as opposed to brain surgery.
Notably, CSF shunts may fail at a relatively high rate (e.g., more than 50% over two years, and even larger percentages over longer periods of time). Further, when CSF shunts fail and otherwise need to be removed and/or replaced, the spinal region may again be a safer region (as compared to the cranial region) to perform a procedure, such as an endovenous procedure.
Considering at least Poiseuille's law (Eq. 1) and Orifice flow (Eq. 2), the shunt ID (circular profile) may be on the order of 0.001″ to 0.005″ if no dedicated flow constriction or valve is present, lending itself to potential occlusion from clotting or protein build up. For example: with Equation 1, taking a shunt tube inner diameter of 0.005″ in with a change in pressure of 10 cm/H2O at a shunt length of 4 centimeters, the volumetric flow rate is calculated to be 13 ml/h or 213 ml/day. This is the idealized scenario ignoring surface effects from the shunt that could further reduce the flow rate. For Equation 2 even when taking the idealized case and disregarding the Coefficient of Discharge with a simple, flow regulation orifice diameter of 0.005″ the flow rate may be calculated to be 63 ml/h or over 1,500 mL/day, which may be too large.
Q=π*Δp*r*48*μ*l Eq 1.
Q=Cd*A*√(2*g*H) Eq 2.
Conventional shunts in the lumbar region that drain into the abdominal cavity may become kinked and obstructed when the lower spine moves. This poses a difficulty in isolating the shunt body and maintaining a tube opening amidst body movements.
As used herein, distal is defined as furthest from the doctor's hand during deployment of the shunt, and proximal as closest to the doctor's hand.
Embodiments disclosed herein relate to CSF shunts with regulators to regulate CSF flow through the shunt. Such flow may be 25-350 ml/day, or for example, approximately 250 ml/day. A regulator in a CSF shunt can include one or more individual regulators which work together to provide an overall flow regulation for the CSF shunt. Regulation may enable greater flow of CSF through the regulator when the CSF is at a higher pressure and enable a lesser flow of CSF through the regulator when the CSF is at a lower pressure. When the CSF pressure is sufficiently low, the regulator may close altogether, thereby preventing flow of fluid through the regulator. When the regulator closes, blood from the venous system is prevented from flowing back through the shunt and towards the intradural region.
Turning to
The inlet 1130 of the CSF shunt 1100 is positioned in the intradural space 20 and receives an inflow of CSF. As shown, the inlet 1130 is in the distal portion 1120 of the CSF shunt 1100, which is coupled on its other side with the shunt body 1110. The inlet 1130 may optionally be on the shunt body 1110, for example, if there is no distal portion 1120. The distal portion 1120 may be used to facilitate implantation of the CSF shunt 1100 through the dura 10. Such implantation techniques are described with respect to
The closed end 1140 of the CSF shunt 1100 is positioned in the ascending lumbar vein 40, although it could be positioned in the iliac vein, the azygos vein, or any suitable location in the patient's venous system. The closed end 1140 may be a cap, a seal, or integrated into other portions of the CSF shunt 1100, such as the shunt body 1110.
The shunt body 1110 is interposed between the inlet 1130 and the closed end 1140. The shunt body 1110 includes a sidewall and a lumen. The shunt body 1110 may include a material such as implantable polymer(s) such as Polyurethane, Polyureathane-copolymers, silicone, a braided composite of polymers, radiopaque markers, a composite of polymers, and/or polymer(s) with a durometer ranging from 60 A to 65 D. The shunt body 1110 may include multiple regions with differing materials or physical properties or may be one uniform region. As shown, the shunt body 1110 includes two regions. Other examples of a shunt body with multiple regions are shown in
The regulator 1150 is located on the sidewall of the shunt body 1110 and extends from the exterior surface of the shunt body 1110 to the lumen. The lumen is in fluid communication with the inlet 1130 and the regulator 1150, such that CSF can flow therebetween. The CSF flow through the lumen is regulated by the regulator 1150, which passes or provides a regulated amount of CSF into the patient's venous system (in the example shown, ascending lumbar vein 450).
Turning to
The shunt body 110 includes a sidewall 112 and a lumen 114. The lumen 114 may be formed by the sidewall 112, as illustrated. The lumen 114 is in fluid communication with the inlet. In an embodiment, the sidewall 112 defines the inlet.
The shunt body 110 (or the shunt itself) may have a length of between 0.5 to 20 cm, such as approximately 5 cm. The sidewall 112 may have an inner diameter of between 0.1 to 1.6 mm, such as approximately 0.5 mm. The sidewall 112 may have an outer diameter of between 0.2 to 2.6 mm, such as approximately 1.27 mm. The sidewall 112 may have a thickness of between 0.05 and 0.38 mm, such as approximately 0.25 mm. The sidewall 112 may be a composite. An example of a composite includes a sidewall 112 with multiple concentric layers. Each layer may include a different material than adjacent layer(s). Such exemplary materials are described above with respect to the shunt body 110. An example of such a composite sidewall 112 includes an outer layer including, e.g., polyurethane 45D and an inner layer including, e.g., 60A polyurethane loaded with PTFE. The outer layer may be made of a higher durometer material and a molecularly different polyurethane to both moderate flow through the discontinuity along with enhancing, as an example, anticlotting impregnation in the material. The inner layer may be made of a lower durometer material to maintain flexibility in the shunt and to be both lubricous to easily accommodate sliding over a positioning wire and help inhibit protein build up. In another embodiment, there may further be an intermediate layer. The intermediate layer may be added, e.g., to strengthen the wall to prevent crushing, to enhance and/or decrease flexibility, to dampen the rate the in which the flow regulator opens, and/or to aid in bonding the inner layer to the outer layer.
A regulator 150 is further shown. The regulator 150 may be similar to the regulator 1150. The regulator 150 selectively allows a regulated portion of CSF to flow from the lumen 114 and into the venous system of the patient.
In the embodiments of
The discontinuity may be formed mechanically by puncturing or otherwise moving a cutting device (e.g., scalpel, razor blade, etc.) across the thickness of the sidewall 112. The discontinuity may be cut by a laser. According to a technique, the discontinuity may be formed by a mold, such that the shunt body 110 includes the discontinuity when it is removed from the mold. According to another technique, an embedded material, such as a non-stick material, may be used to impart the discontinuity in the sidewall. The shunt body 110 may be cast or otherwise first formed with the embedded material embedded therein. Subsequently, the embedded material is removed to impart the discontinuity.
The discontinuity (e.g., slit) can run longitude and or radially or a combination thereof along the shunt body 110. A discontinuity (or multiple discontinuities) may be imparted anywhere along the shunt body 110 that will be in the patient's venous system when the shunt is implanted. For example, the discontinuity (or discontinuities) may be located proximally along the shunt body 110. The slits maybe coated, and or impregnated with anti-clotting and or anti-microbial coatings. A given discontinuity, such as a slit, may have a length of between 0.5 to 4 mm, such as approximately 2.5 mm.
In the case of a slit, it may only open when the CSF pressure exceeds a predetermined pressure by causing the shunt body 110 to radially expand and cause the slit to open.
The sidewall 112 includes an elastic material and/or semi elastic material, such as polyurethane or silicone. When CSF pressure builds up in the lumen 114, the sidewall 112 expands. The inner diameter and/or outer diameter of the sidewall 112 increases. This causes the discontinuity of the regulator 150 to open. The greater the pressure, the greater the expansion, the greater the amount that the discontinuity opens, and the greater the amount of CSF fluid is diverted through the opened discontinuity. The effect of diverting a variable amount of CSF fluid through the regulator 150 in response to a variable pressure of the CSF fluid in the lumen 114 allows the discontinuity-type (or slit-type) regulator 150 to regulate the flow of CSF between the patient's intradural space and the venous system.
As shown in the examples of
Various factors may influence the radial expansion of the shunt body 110 that will determine when and how much the regulator 150 will open. Some of these factors include: the discontinuity length or shape in the regulator 150 (e.g., a longer slit can open at a lower pressure); the durometer of the shunt body 110 (a lower durometer expands easier, and shunt body 110 durometers can range from approximately 35 A up to 55 D); the thickness of the sidewall 112 (a thicker sidewall 112 takes more pressure to radially expand; the inner diameter of the sidewall 112 (smaller diameter requires more head pressure to cause expansion); and/or shunt body 110 cross-sectional shapes (oval, triangular, or other shunt body 110 shapes effect the control opening/closing mechanism of the regulator 150, for example with a specific orientation). These factors relate to the ability of the shunt body 110 to expand radially outward (sometimes referred to hoop strength/stress and/or radial force, and here also inclusive of non-round tube) per a given internal CSF head pressure and an external venous pressure. These elements all combine to define the radial force applied to the shunt body 110. The regulator 150 may activate (i.e., the discontinuity expands and opens) from a predetermined head pressure ranging from approximately 2 cmH2O up to approximately 15 cmH2O when the subarachnoid, intradural CSF pressure is greater than the venous pressure.
Examples of a lower durometer material for the shunt body 110 includes a material with a durometer from 15 A to 90 A, such as approximately 80 A, for example. Examples of a higher durometer material includes a material with a durometer from 35 D to 75 D, such as approximately 55 D, for example. Implantable silicones and some urethanes are examples of materials in the lower durometer grades. Implantable silicones from 15 A up to 40 D and urethanes may range from the 60 A up to 70 D.
When the differential between the CSF in the subarachnoid, intradural space and the intravenous region drops, for example, within the opening pressure at the lower range of the radial force (e.g., at or below 5 cm H2O), the shunt body 110 will constrict back to its original shape and the discontinuity will collapse and close. Thus, the regulator 150 can inhibit regress of blood from the venous system into the shunt body 110.
When the CSF pressure increases, the discontinuity will open accordingly more giving more outflow. This is influenced the shunt body 110 parameters discussed above, and the discontinuity act as a flow regulator.
The discontinuity(ies) opening and closing pressure may be influenced by the radial force applied on the shunt body 110. The configuration of the discontinuity (e.g., shape, orientation) may be selected in view of the factors discussed above. Many of the factors described above can be adjusted and may be combined with other design details to impart the desired slit opening pressure and flow regulation. As another example, the sidewall 112 in the region of the regulator 150 may be thinner to impart a lower opening pressure for the discontinuity, or the shunt body 110 can contain irregular and varying geometry (i.e., molded features in the tubing and/or on the inner or outer surface(s) of the sidewall 112) along its length to tailor specific mechanical properties. As discussed above, the sidewall 112 can include a composite material. As further explained above, such layer(s) can, for example, act as dampening mechanism for regulating pressure. In addition, each one of the aforementioned factors can be controlled on any specific segment of the shunt body 110 length to produce the desired regulation by the regulator 150.
As shown in
The second region 318 may have a lower or greater durometer than the first region 316. In the second region 318, the sidewall 312 may have a smaller or larger inner diameter than the sidewall 312 has in the first region 316. According to embodiments, the lower durometer and/or greater inner diameter region of the sidewall 312 may include a regulator, while the higher durometer and/or lesser inner diameter may not include a regulator. According to an embodiment, the inner diameters between the first region 316 and the second region 318 vary while having the sidewall 312 as a single integrated component.
In another example, the first region 316 of the sidewall 312 has a first cross-sectional shape (e.g., circular), and the second region 318 of the sidewall 312 has a second cross-sectional shape (e.g., semi-triangular, having rounded corners). In the case of a semi-triangular cross-sectional shape, the second region 318 of the sidewall 312 may have regulator(s) on the flat sections or the rounded corners. The thickness of the sidewall 312 may differ in the first region 316 and the second region 318.
According to some embodiments, the regulator(s) 350, 352 may have multiple discontinuities in parallel or that cross or intersect (e.g., X or Y shaped) or have some other spatial relationship with each other.
The regulator 552 may be similar to regulators 150, 350, 352 in respects. In the examples shown, the regulator 552 includes a discontinuity (a slit as shown). The regulator 552 can include a radial section of the sidewall 512 (for example, a semi half circle). The regulator 552 can be cast and integrated into the sidewall 512. The regulator 552 may include or be formed of a different material than other portions of the sidewall 512. Such configurations may be similar to those described with respect to
As shown in
As shown in
For example, the discontinuity 642 allows for a puncture-system-type delivery component 2 to pass through the inner lumen of the shunt body 610 (and/or other portions of the shunt, such as the distal region and inlet (not shown)). In this example, the delivery component 2 can puncture the dura 10 prior to placement of the shunt.
The sleeve 752 includes a distal end 753 and a proximal end 754. The sleeve 752 may be placed at any suitable location along the shunt body 710, as long as the sleeve 752 is to be located within the venous system when the shunt is in situ. It may be possible to have multiple sleeves 752 and corresponding discontinuities 751. At least a portion of either the distal end 753 or the proximal end 754 may be coupled (e.g., sealed, attached, bonded) to the shunt body 710. At least a portion of the other end may not be coupled to the shunt body 710 and may be a free end. In an embodiment, a portion of the distal end 753 or the proximal end 754 is coupled to the shunt body 710 in some areas and not coupled in other areas. In an embodiment, the distal end 753 is coupled with the shunt body 710 and the proximal end 754 is a free end. This embodiment is shown in
The sleeve 752 may include a semi-elastic or elastic material (e.g., durometer of 15 A to 90 A, such as approximately 50 A). This material can be implanted in the sleeve 752 and may be the same or different from the material of the shunt body 710. Examples of a material included in the sleeve 752 include high PTFE loaded, low to high durometer urethanes, low or high durometer silicones, a straight PTFE sleeve, elastomeric, and/or the like. In addition, the sleeve material maybe coated with antibacterial and or anticlotting materials, e.g Heparin or such. The sleeve may be a composite in that the underlayer material overlays on the shunt and the outer material contacts the blood.
As shown, for example, in
As discussed, multiple regulators may be included in a shunt, such as two or more of the regulators disclosed herein. One of the regulators may be a primary regulator and may open to allow for relatively small amounts of CSF flow at relatively low CSF pressure. A secondary regulator may open at higher CSF pressure to further increase the CSF flow through the shunt. The pressure to open the first regulator may be lower than the pressure to open the second regulator. Further regulators may be designed to open at different predetermined pressures.
An exemplary regulator(s) may stop blood regress by constricting and sealing shut at a predefined pressure (e.g., between approximately 1 to 12 cmH2O, such as 7 cmH2O). A given constricting/sealing pressure may be selected according to a patient's diagnosis. For example, patients who are diagnosed with NPH may need the predetermined sealing pressure to be lower to reduce effects of hydrocephalus, whereas patients with IIH may need the predetermined sealing pressure to be higher.
The regulator 1250 (which may be in addition to other regulators) includes a discontinuity 1251 in the sidewall of the shunt body 1210. The discontinuity may be shaped, be configured, or function in a similar manner as other discontinuities described herein (e.g., multiple discontinuities, various shapes, etc.). The regulator 1250 further includes a flow restrictor 1252. In the depicted embodiment, the flow restrictor 1252 is a flap. The flow restrictor 1252 may extend or be part of the inner surface of the sidewall of the shunt body 1210. The flow restrictor 1252 may extend underneath and across the discontinuity 1251. The flow restrictor 1252 may extend along the axial length of the discontinuity 1251 or only a portion thereof. The flow restrictor 1252 may be formed of or include the same material(s) as the shunt body 1210 or different material(s).
As shown in
The flow restrictor 1252 may have one or more apertures. The aperture(s) may align partially or completely with the discontinuity 1251. The apertures in the flow restrictor 1252 may function such that CSF can still flow through the discontinuity 1251 even when the CSF pressure is particularly high, but CSF can only flow through the regulator 1250 at a lower rate because it will only be able to flow through the apertures in the flow restrictor 1252, even with the flow restrictor 1252 is in the closed state.
The insert 1370 includes a discontinuity 1352. The discontinuity 1352 may be elongate or may be similar to other types of discontinuit(ies) described herein and may be formed in similar ways. The discontinuity 1352 may extend along and underneath at least a portion of the discontinuity 1351. In such a way, the discontinuity 1351 and the discontinuity 1352 are partially or completely aligned, such that under certain conditions, CSF can flow through the discontinuities 1351, 1352. The discontinuity 1352 may behave, function, or perform like other discontinuities described herein (e.g., open under greater pressure, close under lesser pressure, etc.). The discontinuity 1352 may remain open through a range of expected CSF pressures, and this may be different from the discontinuity 1351, which may, in contrast, both open and close based on CSF pressure.
Further, a flow restrictor 1353 is also shown in
The shunt body 1410 may be similar to other shunt bodies described herein. The regulator 1450 (which may be in addition to other regulators) is arranged within the lumen of the shunt body 1410. The regulator 1450 includes a rigid portion 1451 and a flow restrictor 1452. The rigid portion 1451 may be substantially rigid in that it may not substantially deflect or deform under a range of expected CSF pressures (e.g., the rigid portion 1451 will not substantially deform or deflect at the maximum expected CSF pressure). The rigid portion 1451 may be integral with the shunt body 1410 or may be a separate piece. The rigid portion 1451 may be thicker than the flow restrictor 1452 along the axial dimension. The rigid portion 1451 may be a half-moon extending halfway through the lumen of the shunt body 1410 (as shown), or may have other shapes (e.g., a toroid, a half moon that extends less or more than half way through the lumen of the shunt body 1410, a wall extending through the thickness of the lumen of the shunt body 1410 with a number of aperture(s), or the like). Some or all of such aperture(s) may or may not be partially or completely covered by the flow restrictor 1452 when it is closed, as will be further described.
The flow restrictor 1452 may also be positioned in the lumen of the shunt body 1410 and upstream of the rigid portion 1451. The flow restrictor 1452 may be a relatively flexible component, as compared to the rigid portion 1451. The flow restrictor 1452 may be elastic and may have memory. The flow restrictor 1452 may have various shapes, such as the various shapes described with respect to the rigid portion 1451. The flow restrictor 1452 may be connected to the shunt body 1410 along the entire lower and lateral perimeter (e.g., the “U” shape shown in
At lower CSF pressure, the flow restrictor 1452 may remain in its default position (e.g., its relaxed position), an example of which is shown in
The stiffening member 1580 may be located in a region of a regulator 1550 (which may be similar to other regulators described herein). The stiffening member 1580 may allow flow of CSF fluid through the lumen of the shunt body 1510 and through the regulator 1550.
The stiffening member 1580 may reduce the risk of the CSF shunt kinking and/or bending after or during implantation. The stiffening member 1580 may tend to straighten the shunt body 1510 in the region where the stiffening member 1580 is present. The stiffening member 1580 may be positioned in a region proximate to or coextensive with the regulator 1550 to prevent undue kinking and/or bending in the region of the regulator 1550. In regions where the shunt body 1510 does not contain the stiffening member 1580, the shunt body may maintain its flexibility, which may be advantageous for the implantation procedure.
According to embodiments, a CSF shunt can contain an emergency shutoff ring. This ring could be a Nitinol actuator ring that is activated by radio frequency to heat the ring, such that it constricts (or closes altogether) to act as emergency stop gate. The austenite finish (AF) temperature can be set around 40 C to 50 C to activate and constrict the ring. In contrast, the ring could be actuated to increase in diameter to open up a segment of the shunt and/or allow for increased CSF flow through the shunt. The Nitinol may be activated. Nitinol can “remember” its original shape (SM)—this when deformed at a low temperature, it can return to its original form upon heating above its transformation temperature, i.e., Af.
According to embodiments, the shunt body and regulator region can be excited by vibration, such as ultrasonic waves. This could allow the shunt to be vibrated in-vivo by, for example, a hand-held device outside of the patient and cleared of build ups on the shunt and/or in and around the regulator. Certain section(s) could contain embedded particles, molecular elements, and or components that are excited by particular radio frequencies.
The shunt could be longer allowing the proximal end and regulator section to reside in a larger vessel such as the Iliac vein and/or femoral vein and have a mechanically/electrically controllable valve. The mechanically/electrically controllable valve could allow a physician to reprogram the desired valve flow rate or reset the valve using a hand-held controller.
It will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the novel techniques disclosed in this application. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the novel techniques without departing from its scope. Therefore, it is intended that the novel techniques not be limited to the particular techniques disclosed.
This application claims priority to and the benefit of U.S. Prov. No. 63/618,049, filed on Jan. 5, 2024, the entirety of which is incorporated by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| 63618049 | Jan 2024 | US |
