Cerebrospinal fluid shunt

Abstract

The method includes the steps of introducing a shunt into the vascular system, the shunt including an entrance opening at an entrance region and an exit opening at an exit region; positioning the entrance region within an epidural or intervertebral vein; puncturing the wall of the epidural or intervertebral vein with a stylet, crossing the interstitial space, and puncturing the dural sac, the stylet including a wire extending through the shunt; moving the shunt so that the entrance region extends through the wall of the epidural or intervertebral vein; moving the shunt so that the entrance region extends into the interstitial space; and moving the shunt so that the entrance region extends through the dural sac, with the entrance region positioned in the intradural space and the exit region positioned in the venous access.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 446,064, filed February 16, 2023, which is incorporated herein by reference in its entirety.

[0002]

[0002] Generally, this application relates to cerebrospinal fluid (CSF) shunts. [Background technology]

[0003] Summary of the Invention

[0004]

[0019] According to an embodiment, a method for intravenously positioning a cerebrospinal fluid shunt in a patient includes the steps of: introducing a cerebrospinal fluid shunt into the patient's vascular system, the cerebrospinal fluid shunt including an inlet opening at an inlet region and an outlet opening at an outlet region, the inlet opening and the outlet opening being in fluid communication with each other; positioning the inlet region of the cerebrospinal fluid shunt into an epidural or intervertebral vein; and using a stylet to puncture the wall of the epidural or intervertebral vein, cross the interstitial space, and insert the shunt into the dural sac. The method includes puncturing the dural sac (epidural or intervertebral vein) with a stylet including a wire extending through the cerebrospinal fluid shunt; moving the cerebrospinal fluid shunt so that an entrance region extends through the wall of the epidural or intervertebral vein; moving the cerebrospinal fluid shunt so that the entrance region extends into the interstitial space after the step of moving the cerebrospinal fluid shunt so that the entrance region extends through the wall of the epidural or intervertebral vein; and moving the cerebrospinal fluid shunt so that the entrance region extends into the interstitial space after the step of moving the cerebrospinal fluid shunt so that the entrance region of the cerebrospinal fluid shunt is positioned in the intradural space and the exit region of the cerebrospinal fluid shunt is positioned in the venous line. The epidural or intervertebral vein may be located in the patient's lumbar region. The epidural or intervertebral vein may be located in the patient's chest. The epidural or intervertebral vein may be located in the patient's neck. The epidural or intervertebral vein may be located in the patient's sacrum. Venous pathways through which the cerebrospinal fluid shunt outlet opening may be located include at least one of the following: an epidural vein, an intervertebral vein, a paravertebral vein, a lumbar vein, an iliac vein, a femoral vein, an azygos vein, a hemiazygos vein, an inferior vena cava, a superior vena cava, the right atrium of the heart, or a venous tributary of the inferior vena cava or the superior vena cava. The method may further include, after puncturing the dural sac, deploying an anchor in the intradural space to stabilize the cerebrospinal fluid shunt inlet region relative to the dural sac. The method may further include, before puncturing the dural sac, deploying a limiter at least partially in the interstitial space, the limiter determining the maximum length of the cerebrospinal fluid shunt extending through the dural sac into the intradural space.The step of deploying the limiter may include expanding the limiter so that the outer diameter of the limiter is greater than the outer diameter of the lateral region of the CSF shunt between the inlet and outlet regions. While the inlet region of the CSF shunt may be located in the intradural space, the outlet region of the CSF shunt may be located in one of an epidural vein, an intervertebral vein, a lumbar vein, an iliac vein, or a perivenral vein. The CSF shunt may include silicone. The CSF shunt may include polyurethane. The CSF shunt may include nitinol. The CSF shunt may include at least one radiopaque marker. The CSF shunt may include a material on at least one of the exterior of the CSF shunt or the interior of the inlet region configured to reduce at least one of blood clotting, protein aggregation, or cell aggregation. The CSF shunt may include an anti-reflux mechanism between the inlet and outlet openings, the anti-reflux mechanism being configured to reduce or prevent retrograde blood movement. The cerebrospinal fluid shunt may include a flow regulator between the inlet and outlet openings, and the flow regulator may be configured to regulate the flow of cerebrospinal fluid between the inlet and outlet openings. Introducing the cerebrospinal fluid shunt into the patient's vasculature may include introducing the cerebrospinal fluid shunt into a leg vein, a neck vein, or an arm vein. The method may further include removing the cerebrospinal fluid shunt by engaging a shunt removal feature of the cerebrospinal fluid shunt. The method may further include temporarily dilating at least one of an opening through one of the walls of an epidural vein or an intervertebral vein, a region of the interstitial space, or an opening through the dural sac at at least one dilated location by positioning a balloon at the at least one dilated location and inflating the balloon to dilate the at least one dilated location before or during passage of the shunt through the at least one dilated location.

[0005]

[0020] According to embodiments, a cerebrospinal fluid shunt for placement within a patient includes: an inlet region configured to pass through an opening in an epidural or intervertebral venous wall, pass through an opening in a dural sac, and pass through an interstitial space between either the epidural or intervertebral venous wall and the dural sac; an inlet opening in the inlet region configured to receive cerebrospinal fluid from the intradural space; an outlet region configured to be positioned in the venous line; an outlet opening in the outlet region in fluid communication with the inlet opening and configured to allow cerebrospinal fluid received by the inlet region to flow out of the cerebrospinal fluid shunt; a lateral region between the inlet and outlet regions, the lateral region including a channel allowing fluid communication between the inlet and outlet openings; and an insertion limiting portion located in the lateral region, configured to be positioned in the interstitial space between the epidural or intervertebral venous wall and the dural sac. The shunt may further include at least one radiopaque marker located at least partially in the inlet region, at least one radiopaque marker located at least partially in the lateral region, and at least one radiopaque marker located at least partially in the outlet region. The inlet region may include a bulbous head region. The insertion limiting portion may include a radially protruding portion, and the bulbous head region and the radially protruding portion may be integrated into one piece. This one piece may be coupled to another portion of the cerebrospinal fluid shunt, including the outlet region.

[0006]

[0021] According to embodiments, a system for positioning a cerebrospinal fluid shunt within a patient includes a guide catheter configured to slide over a proximal region of a guide wire positioned in the patient's venous system, the guide catheter including a proximal region and a distal region, the guide catheter including an anchor configured to secure the distal region of the guide catheter in position within the patient's venous system; an adapter coupled to the proximal region of the guide catheter, the adapter configured to selectively prevent fluid flow from the patient from exiting the adapter; a sheath including a proximal region and a distal region, the sheath positioned at least partially within the guide catheter, and a sheath at least partially between the guide catheter and the sheath. a partially positioned shunt, the shunt including an inlet region including an inlet opening, an outlet region including an outlet opening, and a lateral region between the inlet and outlet regions, the lateral region including a channel such that the inlet opening is in fluid communication with the outlet opening, the lateral region configured to extend through a venous wall and through an interstitial space, the inlet region configured to extend through a dural sac into the intradural space, and the outlet region configured to be positioned in a venous line; and a wire configured to extend through the shunt and at least partially out of the inlet opening, the wire including a proximal region and a distal region, the distal region configured to puncture the venous wall and the dural sac. The anchor of the guide catheter may include a balloon. The inlet region of the shunt may further include an anchor configured to stabilize the inlet region relative to the dural sac. The sheath may include a retractable sheath. The lateral region may include a limiter configured to limit the insertion distance of the shunt into the patient.

[0007]

[0022] According to an embodiment, a method for positioning a cerebrospinal fluid shunt in a patient's veins includes the steps of: introducing the cerebrospinal fluid shunt into the patient's vascular system, the cerebrospinal fluid shunt including an inlet opening at an inlet region and an outlet opening at an outlet region, the inlet opening and the outlet opening being in fluid communication with each other; positioning the inlet region of the cerebrospinal fluid shunt into an epidural vein or an intervertebral vein; after positioning the inlet region of the cerebrospinal fluid shunt in the epidural vein or the intervertebral vein, moving the cerebrospinal fluid shunt so that the inlet region extends into the interstitial space; and after moving the cerebrospinal fluid shunt so that the inlet region extends into the interstitial space, moving the cerebrospinal fluid shunt so that the inlet region passes through the dural sac opening, so that the inlet region of the cerebrospinal fluid shunt is positioned at least partially in the intradural space and the outlet region of the cerebrospinal fluid shunt is positioned in the venous line.

[0008]

[0023] According to an embodiment, a method for positioning a cerebrospinal fluid shunt in a patient's veins includes the steps of: introducing the cerebrospinal fluid shunt into the patient's vascular system, the cerebrospinal fluid shunt including an inlet opening at an inlet region and an outlet opening at an outlet region, the inlet opening and the outlet opening being in fluid communication with each other; positioning the inlet region of the cerebrospinal fluid shunt into an epidural or intervertebral vein; moving the cerebrospinal fluid shunt so that the inlet region passes through an opening in the wall of the epidural or intervertebral vein; and, after the step of moving the cerebrospinal fluid shunt so that the inlet region passes through the wall of the epidural or intervertebral vein, moving the cerebrospinal fluid shunt so that the inlet region of the cerebrospinal fluid shunt passes through the opening in the dural sac, so that the inlet region of the cerebrospinal fluid shunt is positioned at least partially within the intradural space and the outlet region of the cerebrospinal fluid shunt is positioned in the venous line.

[0009]

[0024] According to embodiments, a method for positioning a cerebrospinal fluid shunt in a patient's vein includes the steps of: introducing a cerebrospinal fluid shunt into the patient's vascular system, the cerebrospinal fluid shunt including an inlet opening at an inlet region and an outlet opening at an outlet region, the inlet opening and the outlet opening being in fluid communication with each other; positioning the inlet region of the cerebrospinal fluid shunt into an epidural or intervertebral vein; manipulating the cerebrospinal fluid shunt so that the inlet region extends through a wall of the epidural or intervertebral vein; the step of moving the CSF shunt so that the inlet region extends into the interstitial space after the step of moving the CSF shunt so that the inlet region extends into the interstitial space, and the step of moving the CSF shunt so that the inlet region extends through the dural sac after the step of moving the CSF shunt so that the inlet region of the CSF shunt is positioned in the intradural space and the outlet region of the CSF shunt is in fluid communication with at least one of a reservoir or a percutaneous port positioned under the patient's skin. The percutaneous port can be configured to at least one of deliver a drug to the patient, enable drainage of CSF, or facilitate measurement of CSF pressure. [Brief explanation of the drawings]

[0010] [Figure 1]

[0003] A cross-sectional view of a patient's anatomy is shown. [Figure 2]

[0004] FIG. 1 illustrates a cross-sectional view of a patient's anatomy and a delivery system for a CSF shunt according to an embodiment. [Figure 3]

[0005] Figure 3A shows a cross-sectional view of a patient's anatomy and a sequence for positioning a CSF shunt according to an embodiment, Figure 3B shows a cross-sectional view of a patient's anatomy and a sequence for positioning a CSF shunt according to an embodiment, and Figure 3C shows a cross-sectional view of a patient's anatomy and a sequence for positioning a CSF shunt according to an embodiment. [Figure 4A]

[0006] A longitudinal cross-sectional view of a portion of a shunt and a shunt delivery system according to an embodiment is shown. [Figure 5]

[0007] FIG. 1 shows a cross-sectional view of a portion of a patient's anatomy and a CSF shunt in its final position, according to an embodiment. [Figure 6]

[0008] FIG. 1 shows a cross-sectional view of a patient's anatomy and a CSF shunt in its final position, according to an embodiment. [Figure 7]

[0009] Figures 7A, 7B, 7C, and 7D show axial cross-sectional views of different CSF shunt designs, according to embodiments. [Figure 8] 8A and 8B show cross-sectional views of a patient's anatomy and a sequence for positioning a CSF shunt within a patient according to an embodiment. [Figure 9]

[0011] 9A and 9B show different cross-sectional views of a CSF shunt positioned within a patient, according to an embodiment. [Figure 10]

[0012] Figures 10A, 10B, and 10C show cross-sectional views of a CSF shunt with a flow regulator, according to an embodiment. [Figure 11]

[0013] 11A and 11B show cross-sectional views of a portion of a CSF shunt with an anti-reflux valve, according to an embodiment. [Figure 12]

[0014] 1 shows a flowchart of a method for positioning a CSF shunt in a patient's vein, according to an embodiment. [Figure 13]

[0015] Figures 13A, 13B, and 13C show an inner wire and stylet according to an embodiment. [Figure 14] 1 illustrates an inner wire and stylet, according to an embodiment. [Figure 15]

[0016] 1 illustrates a portion of a shunt delivery system and a shunt, according to an embodiment. [Figure 16]

[0017] Figures 16A, 16B, and 16C show a sequence for implanting a shunt using a shunt delivery system, according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011]

[0018] The foregoing summary and the following detailed description of certain technology of the present application will be better understood when read in conjunction with the accompanying drawings. For purposes of illustration, certain technology is shown in the drawings. It should be understood, however, that the claims are not limited to the arrangements and instrumentality shown in the accompanying drawings. Moreover, the features shown in the drawings are one of many ornamental features that may be employed to achieve the described functionality of the system.

[0012]

[0025] Embodiments herein relate to systems and methods for draining excess cerebrospinal fluid (CSF) from a patient's intradural space, particularly the subarachnoid space within the spinal canal. Embodiments herein describe positioning a CSF shunt within a patient using an intravenous approach using a vein in the spinal region.

[0013]

[0026] Cerebrospinal fluid (CSF) is an ultrafiltrate of plasma. It is a virtually transparent liquid with a density similar to that of water. CSF bathes the brain within the skull and the spinal column and spinal nerve roots within the spinal canal. CSF is surrounded by the dura mater (dura mater), a thick, relatively inelastic membrane that lines the skull and spinal canal. In the spinal cord region, the dura mater is called the dural sac. CSF is secreted into the ventricles by the choroid plexus and circulates around the folds of the brain, the spinal cord, and nerve roots. CSF is reabsorbed into venous blood by arachnoid granulations. Some arachnoid granulations surround the brain along the walls of venous sinuses, where CSF enters the sinuses. Other arachnoid granulations are located along nerve roots in the spinal canal, where CSF enters the veins surrounding the nerve roots.

[0014]

[0027] Hydrocephalus is a relatively neurological disorder in which CSF pressure increases for a variety of reasons. Hydrocephalus can be communicating, in which the CSF flow pathway is not interrupted but there is a lack of CSF reabsorption by the arachnoid granulations. Hydrocephalus can also be caused by CSF overproduction. Hydrocephalus can also occur secondary to impaired CSF circulation, which is called non-communicating hydrocephalus. Some hydrocephalus symptoms are congenital, while others can be acquired (e.g., after subarachnoid hemorrhage).

[0015]

[0028] One approach to treating hydrocephalus is by diverting the CSF. CSF diversion, commonly known as shunting, 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 procedure can be performed by a neurosurgeon.

[0016]

[0029] In addition to hydrocephalus, other conditions may be treated by CSF diversion using the techniques described herein. For example, in some patients, conditions such as idiopathic intracranial hypertension (IIH) can cause the ventricles to shrink. In some patients, enlarged ventricles do not increase CSF pressure, resulting in conditions such as normal pressure hydrocephalus (NPH).

[0017]

[0030] Conventional shunts can access CSF from a location within the skull. However, the neurosurgery required to implant such shunts can be relatively risky. For example, when positioning a shunt in the inferior petrosal sinus, such a procedure carries high risks and, if unsuccessful, can lead to neurological complications or even death. The embodiments disclosed herein describe delivery systems and CSF shunts for extracranial placement. In particular, the embodiments disclosed herein relate to placing a CSF shunt in the spinal canal (e.g., in the lumbar region). The lumbar region offers multiple sites accessible via an intravenous catheter guided by X-ray fluoroscopy for delivery and positioning of the CSF shunt. The spinal cord region (e.g., the lumbar region) may be a safer and less risky area for surgery, as opposed to brain surgery.

[0018]

[0031] In particular, CSF shunts can have a relatively high failure rate (e.g., greater than 50% over 2 years and even greater rates over longer time periods). Furthermore, when a CSF shunt fails and requires removal or replacement, the spinal region may be a safer area (compared to the cranial region) for procedures such as intravenous procedures.

[0019]

[0032] According to the technology herein, a cerebrospinal shunt has an inlet region and an outlet region. The inlet region is positioned within the intradural space in the dural sac. The outlet region is positioned at a venous access point. The venous access point can be any path along the venous system. One example of a venous access point extends along the intervertebral veins, to the lumbar, iliac, or paravertebral veins, to a large vein (such as the inferior or superior vena cava), and to the right atrium of the heart. Another example of a venous access point extends along the epidural venous network of the spinal canal. Another example of a venous access point extends along the azygos vein or one of its tributaries, or along a venous tributary of the inferior or superior vena cava.

[0020]

[0033] According to the technology herein, a spinal-venous shunt is implanted using an intravenous procedure to drain CSF from the intradural space into veins, such as epidural veins (veins in the spinal canal) or veins surrounding the spinal column. The shunt may include a hollow tube with an inlet opening at an inlet region within the intradural space. The inlet opening may receive CSF at a higher pressure. The shunt may further include an outlet opening at an outlet region. The outlet opening may deliver the CSF received at the inlet opening to a lower pressure region. For example, the outlet opening may be positioned in a venous line, such as an epidural vein, an intervertebral vein, a lumbar vein, or a vein proximal or distal to the spine. The shunt may further include a lateral region including a channel between the inlet and outlet regions. The channel may connect to or allow fluid communication between the inlet and outlet openings. The shunt may include one or more anti-reflux features (such as a valve or flow control element) and / or flow restriction features.

[0021]

[0034] In accordance with the technology herein, a method for placing a CSF shunt from an intravenous approach is provided, which may include inserting a catheter into a vein adjacent to the dural sac, directing the catheter toward the dural sac, perforating the venous wall, perforating the interstitial space, perforating the dural sac, perforating the arachnoid membrane, and positioning the shunt through the perforation so that the entrance opening is in the intradural space and the exit opening is in a vein surrounding or distal to the dural sac.

[0022]

[0035] According to the technology herein, to implant a CSF shunt, a patient may be anesthetized or sedated and placed on an operating table in front of an x-ray / fluoroscopy system (hereinafter, the fluoroscopy system). A surgeon or a member of a surgical team (hereinafter, the surgeon) may insert a needle into a vein (such as a vein in the patient's leg, neck, or arm). The surgeon may then place an introducer over the needle into the vein and remove the needle. As another example, an introducer may be positioned along with the needle so that the introducer is inserted simultaneously with the needle. The surgeon may inject a fluoroscopic contrast agent into the patient. Using the fluoroscopy system, the surgeon can view the patient's venous system (or relevant portions thereof) on a display. The surgeon may determine the appropriate route for intravenous delivery and implantation of the CSF shunt. Such an appropriate route may be via an epidural vein, an intervertebral vein, or a perivenral vein.

[0023]

[0036] FIG. 1 illustrates an anatomical region of a patient in the spinal cord region (e.g., the lumbar region). Examples of epidural and intervertebral veins are shown. The spinal cord region includes a spinal canal 10 (shown diagrammatically), bones 12, nerves 14, nerve roots 16, fat and / or interstitial space 18, epidural veins 20, intervertebral veins 22, a dural sac 30, and cerebrospinal fluid 32. Interstitial space 18 includes fluid-filled and non-fluid-filled spaces, such as fat (represented by punctate areas). As shown, interstitial space 18 lies anatomically between at least the veins and the patient's dura mater, which bounds dural sac 28. Interstitial space 18 is composed largely of loose tissue and fat, along with small blood vessels, such as capillaries, arterioles, and venules.

[0024]

[0037] FIG. 2 illustrates the distal portion of a shunt delivery system 100 (showing a guide catheter 110, a guidewire 120, and a stabilizer 130 as shown) inside a patient. The guide catheter 110 is positioned such that the tip of the guide catheter 110 is properly positioned (in this example) within the intervertebral vein 22 and the guidewire 120 within the epidural vein 20. The stabilizer 130 is also shown. The guide catheter 110, the guidewire 120, and the stabilizer 130 form part of the shunt delivery system 100, which delivers the CSF shunt 200 to the appropriate location, as will be described below. To properly position the guide catheter 110 and the guidewire 120, the surgeon can insert the guide catheter 110, along with the accompanying guidewire 120, into an introducer (not shown). The guide catheter 110 and / or shunt 200 and other components of the shunt delivery system 100 may be marked with one or more radiopaque (or radiopaque) markers 150 (RO markers, not shown in FIG. 2 ), as described below. The radiopaque markers 150 are easily visually detected by the surgeon through the fluoroscopy system display, thus allowing the surgeon to visualize the system components within the patient's contrast-filled venous system. The radiopaque markers 150 may include one or more materials such as platinum / iridium (90 / 10), gold, palladium, or substantially pure platinum (approximately 99%).

[0025]

[0038] One type of radiopaque marker 150 may be one or more threads (e.g., platinum / iridium threads) extending (substantially longitudinally) along a given component. Such threads may be woven, embedded, incorporated, or attached to a given component described herein, including one or more components of the shunt delivery system 100 and / or shunt 200. The radiopaque markers 150 described herein may facilitate visualization of a particular stage of a procedure by a surgeon through a fluoroscopy system display and may not need to be repeated each time the radiopaque marker 150 is described. The guide catheter 110 may be radiopaque or have a relatively flexible tip bearing radiopaque markers 150 (including platinum / iridium, etc.). Other portions of the guide catheter 110 may be relatively stiff to allow for steering and insertion of the guidewire 120 into the patient. The surgeon may navigate the guide catheter 110 through a vein while watching the process in real time, for example, on a display. Once the tip of the guide catheter 110 is positioned at an appropriate location (e.g., an intervertebral vein, a perispinal vein, an epidural vein, or another appropriate location in the venous pathway), the surgeon can fix the distal portion of the guide catheter 110 at the appropriate location (e.g., an intervertebral vein, a perispinal vein, an epidural vein, or another appropriate location in the venous pathway).

[0026]

[0039] Alternatively, catheterization can be performed using a catheter (not shown) equipped with a guidewire 120, which can be exchanged for the guide catheter 110 over the guidewire 120. The guide catheter 110 includes one or more radiopaque markers 150, allowing the surgeon to visualize the process on a fluoroscopic display while positioning the guide catheter 110 so that its distal end is in the appropriate location (e.g., an intervertebral vein, a perispinal vein, or an epidural vein). The diameter of the guide catheter 110 can range from approximately 3 Fr to 7 Fr, depending on the size of the vein involved. Guide catheters can be relatively short (e.g., less than 50 cm) or relatively long (e.g., more than 90 cm). The length of the guide catheter 110 can be selected depending on the surgical access point. As an example, if the femoral vein is selected for an intravenous procedure and the implantation site is in the lumbar region, the guide catheter 110 can be relatively short (e.g., 30 to 50 cm). If the brachial vein is used and the shunt 200 is implanted in the lumbar region, the guide catheter 110 may be relatively long (eg, 150 cm).

[0027]

[0040] The guide catheter 110 may include a guide catheter stabilizer 130 (or stabilizer) in the distal region of the guide catheter 110. Such a guide catheter stabilizer 130 may include a balloon or mesh inflation device, or a reinforcing element or component. The guide catheter stabilizer 130 may have one or more radiopaque markers 150 for viewing on a fluoroscopy system display. The guide catheter stabilizer 130 may include one or more different materials, including, for example, Pebax, polyurethane, and / or silicone elastic. When the guide catheter stabilizer 130 includes a balloon, the balloon may be oriented substantially coaxially about the guide catheter 110 or may be biased to one or more sides. Additionally, the distal region of the guide catheter 110 may include two or more balloons (e.g., each balloon independently controlled). In such cases, each stabilizer 130 may extend less than 360° around the guide catheter 110 (e.g., one balloon on top and one balloon on the bottom, each extending 180° around the guide catheter 110). If multiple balloons are used, each may be inflated separately. Such inflation may facilitate the surgeon in pointing and directing the distal region (e.g., tip) of the guide catheter 110. The balloons may be inflated through a luer on the proximal handle or through a luer on or within the guide catheter 110.

[0028]

[0041] Alternatively or additionally, the tip of guide catheter 110 can be oriented and secured using a mechanical system. For example, the mechanical system can eliminate the need for stabilizer 130.

[0029]

[0042] Once the guide catheter stabilizer 130 is in place, the surgeon can deploy the guide catheter stabilizer 130 (e.g., inflate the balloon anchor) to stabilize the guide catheter 110 in the proper position within the vein and, if indicated, to orient the guide catheter 110 so that, for example, the long access is centered or off-center along the main axis of the vein. After the guide catheter 110 is properly positioned and / or stabilized, the surgeon can remove the guidewire 120 from the patient. Figure 2 shows an example of the guide catheter 110 positioned and stabilized within the intervertebral vein 22 via the guide catheter stabilizer 130 (in this example, an inflated balloon). Stabilization can be performed before the guidewire 120 is withdrawn.

[0030]

[0043] After positioning and stabilizing the guide catheter 110, the surgeon can introduce additional portions of the shunt delivery system 100 into the proximal end of the guide catheter 110. FIG. 4 shows a longitudinal cross-sectional view of an exemplary shunt delivery system 100 and some additional components of a shunt 200. The shunt 200 may include a shunt body 210, which may include an inlet region 212 and an inlet opening 211, which will receive CSF 32 from the intradural space 30. The inlet region 212 of the shunt body 210 may be distal during the implantation procedure. The shunt body 210 may further include an outlet region 214 and an outlet opening 213, which, once the shunt 200 is implanted, passes the CSF 32 received from the inlet opening 211 to the patient's intravenous space. The shunt body 210 may further include a lateral region 215 between the inlet region 212 and the outlet region 214. The lateral region 215 may include channels that allow fluid communication between the inlet opening 211 and the outlet opening 213, allowing CSF 32 to flow through the shunt body 210 after implantation.

[0031]

[0044] The shunt body 210 may include materials such as polyurethane, silicone, and / or nitinol. The shunt body 210 may include or be coated with materials in the exterior and / or interior regions that reduce blood clotting, protein aggregation, and / or cell aggregation. Such materials may be antithrombotic and may include materials or compounds such as Plavix or heparin.

[0032]

[0045] 4, the shunt 200 may include an anchor 230, which may facilitate stabilization of the shunt 200 after it is fully implanted. The anchor 230 may include multiple anchor fingers 231, which may have one or more radiopaque markers 150. An anchor wire 232 may be included in or on one or more of the anchor fingers 231. The function, deployment, and operation of the anchor 230 are described below.

[0033]

[0046] 4, the shunt delivery system 100 may further include a limiter 140. The limiter 140 may also include one or more radiopaque markers 150 (not shown). The function, deployment, and operation of the limiter 140 are described below.

[0034]

[0047] As shown in FIG. 4, the shunt delivery system 100 may further include a sheath 170 (e.g., a retractable sheath) over some or all portions of the shunt 200. The sheath 170 may have one or more radiopaque markers 150 (not shown in FIG. 4, but shown in FIGS. 8A and 8B). The sheath 170 may include a distal region (distal from the surgeon) and / or a distal tip suitable for piercing or facilitating piercing of a portion of the patient's anatomy. The sheath 170 may interface with an inner wire 160 to pierce or facilitate piercing. The sheath 170 may be coated with or include a lubricious material, such as those described herein. For example, the sheath 170 may have a laminate structure, with the inner layer of the laminate proximal to the shunt 200 being composed of a lubricious material, such as PTFE. Such a lubricious material may facilitate removal of the sheath 170 from the shunt 200. Outside the layer of lubricious material may be a stiffer layer or an interlayer wire braid to improve stiffness, pushability, and / or trackability. Outside the stiffer layer may be one or more additional layers suitable for different purposes.

[0035]

[0048] As shown in FIG. 4 , the shunt delivery system 100 may further include an inner wire 160 extending through the shunt body 210 (e.g., through the exit opening 213, the side channel 215, and the entrance opening 211). The inner wire 160 may include one or more radiopaque markers 150. The inner wire 160 may include a distal region and / or tip 162 suitable for piercing or facilitating piercing a portion of a patient's anatomy. The inner wire 160 may include a hollow tube running therethrough, including the entrance and exit openings. The inner wire 160 may include either a biometal and / or a bioplastic and / or include a movable and / or removable stylet 165 therein. The stylet 165 and / or hollow tube may include nitinol (such as superelastic nitinol) for increased flexibility or pushability.

[0036]

[0049] 13A and 13B show cross-sectional views along the major axis and top views of different embodiments of the inner wire 160 and stylet 165. FIG. 13C shows a cross-sectional view along the major axis of the inner wire 160 and stylet 165, according to an embodiment. FIG. 14 shows cross-sectional views along the major axis and axial direction of the inner wire 160 and stylet 165, according to an embodiment. As shown in FIG. 13A, the distal region of the inner wire 160 can include a rounded or shovel-shaped configuration. The edge of the distal tip of the inner wire 160 can be sharp (e.g., razor-like). The edge of the distal tip of the inner wire 160 can include a bevel. Other configurations of the inner wire 160 and / or stylet 165 are shown in FIG. 13B (uneven tip type) and FIG. 13C (conical tip). After advancing the inner wire 160 through the dural sac 28 (and / or advancing the inner wire 160 further into the intradural space 30 to provide additional stability for deploying the shunt 200), the stylet 165 is removed, thus empting the inner hollow passageway and allowing the surgeon to withdraw CSF 32 to confirm that the distal tip of the inner wire 160 is within the intradural space. In this embodiment, the CSF 32 flows through a hollow tube within the inner wire 160. Removal of the stylet 165 also allows the hollow interior region of the inner wire 160 to be used for drug delivery, contrast delivery to confirm location within the intradural space 30, or pressure monitoring / reading.

[0037]

[0050] The stylet 165 may include a sharp distal tip (e.g., razor-like). In such cases, the inner wire 160 may or may not have a rounded edge (e.g., different from a razor). The distal tip of the stylet 165 may be beveled, faceted, semi-shovel-shaped ( FIG. 13B ), or conical ( FIG. 13C ) to form a sharp tip, which may be advantageous for penetrating tissue. In other embodiments, the stylet 165 may have a trocar-shaped or screw-shaped distal tip. When a screw-shaped tip is used, the stylet 165 and / or inner wire 160 may be rotated to facilitate tissue penetration. The stylet 165 may be coated or include a material (e.g., PTFE) to enhance lubricity and facilitate movement. When positioning the shunt 200 for puncture, the stylet 165 may be retracted and locked onto the inner wire 160 (via the handle). Once the inner wire 160 is positioned within the vein and before puncturing the vein wall, the stylet 165 can be advanced to create an opening, incision, and / or breach in one or more tissues between the vein and the CSF 32 (such as the vein wall, the interstitial space 18, and / or the dural sac 28). These openings, incisions, and / or breaches can facilitate the advancement of the shunt 200 and / or other portions of the shunt delivery system 100. For example, expansion of one or more portions of the shunt 200 can be facilitated to enlarge one or more portions of the hollow interior region of the shunt 200. Such a technique can collapse portions of the shunt 200 while navigating the shunt 200 to its final implantation location (e.g., when an area with channel dimensions smaller than the uncollapsed outer diameter of the shunt 200 is encountered). After puncture, the stylet 165 can be partially or completely withdrawn.

[0038]

[0051] Although a stylet 165 is disclosed, the inner wire 160 itself may perform the puncture without the stylet 165. In such a configuration, the inner wire 160 may be a type of stylet. In such an embodiment, the inner wire 160 may be solid rather than hollow, or may at least not have a hollow channel traversing its length. According to another embodiment, the inner wire 160 and the stylet 165 may each provide the puncture function.

[0039]

[0052] The surgeon can navigate the shunt delivery system 100, which further includes a handle (not shown) outside the patient. The surgeon can manipulate the handle to move the stylet 165 forward (and / or backward) a controlled distance. The handle also includes a lockout / lock-in engagement feature, allowing the stylet 165 to move forward or backward when manipulated by the surgeon. The handle may also include a luer for fluid connection with the inner wire 160. The handle may also include a mechanism (such as a lock-in / lockout twist mechanism) for removing the stylet 165 from the shunt delivery system 100. Thus, the position of the stylet 165 can be locked unless intentionally manipulated by the surgeon.

[0040]

[0053] The inner wire 160, in conjunction with the sheath 170 and / or the distal region of the shunt, can facilitate puncturing or perforating the patient's anatomy (e.g., perforating a vein wall, tissue of the interstitial space 18, or the dural sac 28). The inner wire 160 can also aid in positioning the shunt delivery system 100 in the appropriate location. Although not shown, the inner wire 160 may include or be attached to a handle in an area proximal to the surgeon (e.g., not inside the patient). The surgeon can manipulate the handle to move the inner wire 160 and the entire shunt delivery system 100 into the appropriate position. The handle may be the same handle described above in conjunction with the stylet 165.

[0041]

[0054] As shown in Figure 8A (which includes a longitudinal cross-sectional view of the shunt delivery system 100), the inner wire 160 may include a shoulder. When the surgeon moves the shunt delivery system 100 (e.g., via a handle) onto the inner wire 160, the shoulder of the inner wire 160 may engage the shunt body 210 (e.g., the exit region 214 of the shunt body 210) and / or an intermediate spring 180 (not shown in Figure 8A but understandable from Figure 4) between the inner wire 160 and the shunt body 210. In this manner, the shoulder of the inner wire 160 may allow the shunt delivery system 100 to be properly manipulated and positioned.

[0042]

[0055] 3A, 3B, and 3C illustrate an exemplary sequence for positioning the shunt delivery system 100. In FIG. 3A, after the guide catheter 110 is stabilized within the vein by the stabilizer 130, the surgeon advances the shunt delivery system 100 to at least partially emerge from the distal end of the guide catheter 110. The exterior of the shunt delivery system 100 includes a sheath 170 with radiopaque markers 150, allowing the surgeon to easily visualize the positioning of the shunt delivery system 100 in the patient. The exterior of the shunt delivery system 100 may also include an outer surface of a limiter 140. The outer surface of the limiter 140 may be integral with or part of the sheath 170. The limiter 140 may also include a radiopaque marker (not shown) 150.

[0043]

[0056] Following FIG. 3A, the surgeon advances the shunt delivery system 100 so that the distal end of the shunt delivery system 100 (e.g., the inner wire 160 and / or sheath 170) pierces or moves through the venous wall until the distal end is positioned in the patient's interstitial space 18 near the dural sac 28, as shown in FIG. 3B. At this stage, the limiter 140 may be deployed (e.g., expanded or inflated) by the surgeon. The limiter 140 may be a structure or feature that prevents the shunt delivery system 100 from being inserted too far into the intradural space 30 through the dural sac 28, or may adjust the distance the shunt delivery system 100 can be inserted into the subarachnoid space. The limiter 140 may be an expandable bulge with an outer diameter larger than the outer diameter of the sheath 170. The limiter 140 may comprise a wire cage / tube (e.g., flexible nitinol) that expands in the center when compressed, or may be a rubber material that expands in the center when compressed.

[0044]

[0057] A surgeon may be able to remotely deploy the limiter 140 from outside the patient. The surgeon may be able to remotely deploy the limiter 140 via an actuator on the handle, such as a rotation mechanism (e.g., at the proximal handle end) that engages and expands the limiter 140 when rotated. As another example, the limiter deployment mechanism may include a lever that engages and expands the limiter 140 when moved in one direction (e.g., pushed forward) and disengages and contracts the limiter 140 when moved in a different direction (e.g., pulled backward). The limiter deployment mechanism may include a clicker and may include a governor to prevent overexpansion. The limiter 140 may be at least partially or fully deployed while positioned in the vein and / or interstitial space 18. The limiter 140 may be at least partially or fully deployed while positioned in the interstitial space 18.

[0045]

[0058] Following FIG. 3B, the surgeon advances the shunt delivery system 100 until the distal end of the shunt delivery system 100 (e.g., the inner wire 160 and / or sheath and / or head of the shunt 200) pierces or moves through the venous wall, the interstitial space 18, and is positioned in the intradural space 30, as shown in FIG. 3C. The limiter 140 may be fully deployed before the shunt delivery system 100 is fully positioned in place. The limiter 140 may prevent overinsertion by having an outer diameter larger than the opening through the dural sac 28 created by the shunt delivery system 100 piercing. FIG. 4 shows a portion of the limiter 140 positioned inside the sheath 170. As shown, the limiter 140 may be a balloon that can be selectively inflated (e.g., under the surgeon's control). When the balloon expands, the outer surface of the sheath 170 expands, providing the effect shown in FIGS. 3B and 3C.

[0046]

[0059] FIG. 8A illustrates a stage in the deployment of a CSF shunt 200 using the shunt delivery system 100. The limiter 140 is shown as an exterior feature of the sheath 170. This embodiment of the limiter 140 may differ from the other limiters 140 illustrated herein. The limiter 140 may be a relatively small inflatable balloon. As another example, the sheath 170 may be configured such that upon forward advancement (e.g., via a handle) a predetermined distance, the sheath 170 buckles (e.g., a small corrugated section within the sheath promotes buckling) to create the limiter 140. As shown, the inner wire 160 can puncture the dural sac 28, optionally with the assistance of the sheath 170 (not shown), to create a suitable opening in the dural sac 28.

[0047]

[0060] There are various techniques for implanting the shunt 200. In one method, the sheath 170 is removed, exposing the shunt 200. For example, once the system has penetrated the dural sac 28 (e.g., as seen on a live x-ray) and the shunt 200 is in place, the surgeon can loosen the coupler (e.g., a grommet) to allow the inner wire 160 and / or shunt 200 to move independently of the sheath 170. The surgeon removes the slack from the system, then uses one hand to lock the handle in place on the operating table (e.g., the handle may move), places the other hand on the Y-adapter, and (with the other hand) slides the Y-adapter back toward the handle, exposing the shunt 200 by moving the sheath 170 away from the shunt 200 (e.g., 10–20 mm). Such locking can keep the inner wire 160 stationary.

[0048]

[0061] Alternatively, the shunt 200 can be advanced out of the sheath 170. For example, once the system has penetrated the dural sac 28, the surgeon can loosen the coupler (e.g., a grommet) to allow the inner wire 160 and / or shunt 200 to move independently of the sheath 170. The surgeon can push the handle forward to position the shunt 200 in its final position. Once the shunt 200 is positioned, the surgeon can lock the handle in place and retract the remainder of the sheath 170, clear of the shunt 200 and out of the patient.

[0049]

[0062] As shown in FIG. 5 , the anchor 230 of the shunt 200 is deployed within the intradural space 30. The anchor 230 may include multiple fingers 231. Each anchor finger 231 may be provided with at least one anchor wire 232 and may have one or more radiopaque markers 150. The anchor wire 232 may be formed from or include a material such as nitinol. The anchor wire 232 may be flexible and have memory. The anchor wire 232 may function as a spring. When the anchor fingers 231 and the anchor wire 232 therein or thereon are covered by a sheath 170, they may store energy. When the anchor wire 232 is not covered by a sheath, the anchor wire has a tendency to loosen, which may cause the anchor wire 232 (along with the anchor fingers 231) to spread away from the longitudinal axis of the shunt body 210. The anchor wire 232 attempts to return to its original memory position, thereby expanding so that the anchor fingers 231 at least partially abut the dural sac 28. The force of the anchor fingers 231 on the dural sac 28 may tend to stabilize the shunt 200. The anchor wire 232 may not completely return to its original memory position, facilitating relatively firm contact between the anchor fingers 231 and the inner surface of the dural sac 28. Once (or before) the insertion process is complete, the shunt inlet opening 211 may be in fluid communication with the intradural lumen 30. In this manner, the shunt inlet opening 211 may receive CSF 32.

[0050]

[0063] Figures 7A, 7B, 7C, and 7D show axial views of various embodiments of anchor fingers 231. Figure 7A shows a substantially rounded finger 231, which may include a biopolymer (e.g., silicone, urethane, etc.) with an annular radiopaque marker 150 (e.g., shown as a ring) around a rounded anchor wire 232 (although other shapes are possible). The anchor wire 232 may be composed of, for example, one or more elastic metals or biopolymers. The anchor wire 232 may have memory or otherwise function as a spring. Figure 7B shows an anchor finger 231 with two anchor wires 232, although more anchor wires 232 are possible. While the anchor wires 232 are shown as square or rectangular in shape, other shapes are also possible. The anchor finger 231 may include a radiopaque marker 150, which may be an embedded bead, length, wire, or other configuration. Figure 7C shows an anchor finger 231 having a flattened anchor wire 232 with a radiopaque marker 150, which can be a bead, a length of wire, or another arrangement. Figure 7D shows that the radiopaque marker 150 can be included inside the wire.

[0051]

[0064] 6 shows an example of a shunt 200 in its final position within the body. The shunt inlet region 212, along with anchor fingers 231 (and associated anchor wires 232 and radiopaque markers 150), may be positioned within the intradural space 30. The shunt inlet opening 211 may optionally be located within the intradural space 30 or may be positioned outside the intradural space, within an opening in the dural sac 28, or the like. The shunt lateral region 215 may extend through the interstitial space 18, the venous wall, and a portion of one or more veins. The shunt outlet region 214 and the shunt outlet opening 213 may be positioned within the veins.

[0052]

[0065] The shunt 200 may have a variety of dimensions. For example, the length of the shunt body 210 may be 5 mm to 150 cm. According to embodiments, the shunt body 210 may be less than 100 mm. Such a length is advantageous because it reduces the length of the shunt body 210 that comes into contact with blood, potentially reducing the risk of clotting. Furthermore, a shorter shunt 200 may reduce the residence time of a given portion of the CSF fluid 32 within the shunt 200, potentially reducing the accumulation of proteins that could narrow the inner hollow region of the shunt 200 or interfere with (e.g., clog) the operation or structure of the anti-reflux valve 240 of the shunt 200. The length of the anchor fingers 231 may be 1 mm to 2 cm. The inner diameter of the lateral region of the shunt 200 may be 0.05 mm to 1 mm. The portion of the shunt 200 that extends through the dural sac 28 may be 270 μm to 100 mm. The portion of the shunt 200 that extends through the interstitial space 18 may be between 0.1 mm and 10 mm. The portion of the shunt 200 that extends through the venous wall may be between 0.1 mm and 0.5 mm. The portion of the shunt 200 that extends through the venous lumen (along the venous pathway) may be up to 150 cm.

[0053]

[0066] 9A and 9B show different views of an embodiment of the shunt 200 in its final position within the body. In this embodiment, the anchor 230 may lack fingers. Instead, it may operate by expanding into a donut-like or round gasket-like shape, etc., to secure the shunt 200 inside the dural sac 28. This mechanism allows the distal shunt region to be pre-formed (as shown in FIG. 9B) before loading the shunt 200 onto the guide catheter 110. Thus, the anchor 230 is compressed or deformed in the distal region of the guide catheter 110 and may be at least partially contained by the sheath 170 prior to deployment. When the sheath 170 is retracted (or the shunt 200 is advanced), the distal region of the shunt 200 may return to its original shape, as shown in the example of FIG. 9B. As shown in FIG. 9B, the shunt 200 may further include a reinforcement 220 extending across the opening in the dural sac 28. The reinforcement material 220 may extend into the interstitial space 18 and / or the intradural space 30. The reinforcement material 220 may be embedded in or form part of the shunt body 210 or other portions of the shunt 200. The reinforcement material 220 may tend to prevent collapse or compression of the shunt 200 (e.g., the shunt body 210) (e.g., due to pressure from the dural sac 28). The reinforcement material 220 may include a material with a relatively high durometer (e.g., higher than certain other portions of the shunt body). Examples of materials that may be included in the reinforcement material include PTFE, HDPE, braided wire tubing, and radiopaque embedded metal tubing. The length of the reinforcement material 220 may be, for example, 1 to 20 mm, and may allow the inside diameter (ID) of the shunt 200 (e.g., the shunt body 210) to remain substantially open even in the presence of compression of the dural sac 28.

[0054]

[0067] As further shown in Figure 9B, the shunt 200 may include an external anchor 250 that functions in conjunction with anchor 230 to facilitate stabilization of the shunt 200. The external anchor 250 may be pre-shaped (e.g., in the shape shown in Figure 9B) prior to loading into the sheath 170 and deployed in a manner similar to anchor 230 described above.

[0055]

[0068] FIGS. 10A, 10B, and 10C illustrate another embodiment of a shunt 200 with a flow regulator (particularly shown in FIGS. 10B and 10C). The shunt 200 may be similar to that shown in FIGS. 9A and 9B, but with the addition of a flow regulator. FIG. 10A illustrates the dashed region along the lateral region 215 of the shunt body 210. FIGS. 10B and 10C generally correspond to the dashed region in FIG. 10A. The lateral region 215 of the shunt body 210 includes a collapsible region 216. The collapsible region 216 may be located within the vein and / or interstitial space 18. The collapsible region 216 may be composed of a softer or more flexible material that is more sensitive to external pressure (outside the shunt 200) and internal pressure (inside the shunt 200). Exemplary pressures are indicated by the letter "P." If pressure within the channels within the shunt 200 decreases or pressure from outside the shunt 200 increases, the collapsible region 216 may partially collapse (FIG. 10B), and therefore the inner diameter of the shunt 200 at the collapsible region 216 may have a smaller minimum distance than other portions of the channels (either in the collapsible region 216 or other portions of the lateral region 215 of the shunt body 210). If the pressure is sufficient, the collapsible region 216 may collapse completely (FIG. 10C), and therefore the minimum inner diameter of the channels within the shunt 200 at the collapsible region 216 may be approximately zero. As the inner diameter of the channels at the collapsible region 216 decreases, the amount of CSF 32 that can flow through the shunt 200 may also decrease. In this manner, the rate of flow of CSF 32 may be adjusted in response to changing pressures of the CSF fluid 32 and / or fluid in the venous and / or interstitial spaces 18.

[0056]

[0069] 11A and 11B show cross-sectional views of a shunt 200 positioned in a venous line, including an anti-reflux valve 240 within the shunt body 210, according to an embodiment. The anti-reflux valve 240 may be located at any suitable location along the channel between the inlet opening 211 and the outlet opening 213, or optionally at the openings 211, 213 themselves. As shown in FIG. 11A, the shunt body 210 may be positioned in the venous line. CSF 32 may flow through a channel within the shunt body 210, through the valve 240 in the open position, and into the vein through the outlet opening 213. The flow of CSF 32 is indicated by straight lines with arrows. Blood may flow outside the shunt body 210 within the vein. This blood flow is indicated by wavy lines with arrows. As shown in FIG. 11B, the valve 240 may be moved to a closed position to prevent or reduce the flow of blood back through the channel of the shunt body 210 upstream toward the intradural space 30. If the CSF 32 flow pressure is lower than the blood flow pressure (eg, if the CSF 32 flow pressure decreases and / or the blood flow pressure increases), the valve 240 may close.

[0057]

[0070] The valve 240 may be programmable or non-programmable. A non-programmable valve 240 can open when the pressure in the intradural space 30 exceeds a certain level. This level can be determined by the valve 240 itself and cannot be changed. A programmable valve 240 allows the surgeon to adjust the level. For example, the adjustment itself can be non-invasive, utilizing a magnet (e.g., handheld), and can be performed in a clinic setting (e.g., outpatient). Additionally, there may be an anti-siphon device or component (not shown) that can prevent or reduce excessive drainage of CSF 32 based on the patient's position in space. The anti-siphon component may be integrated into the valve 32 or placed inline within a channel along the path of the shunt body 210.

[0058]

[0071] FIG. 15 illustrates an embodiment of a shunt 200 and a shunt delivery system 100. FIGS. 16A-16C illustrate an embodiment for implanting the shunt 200 using the shunt delivery system 100 of FIG. 15. The shunt 200 and shunt delivery system 100 may be similar to other embodiments described herein. As shown in FIG. 15, a sheath 170 is loaded onto a guide catheter 110. The sheath covers at least a portion of a shunt body 210 (not visible in FIG. 15). The shunt body 210 may have one or more radially protruding portions 260 (three shown) and a bulbous head region 270 connected thereto. The bulbous head region 270 may be at an inlet region of the shunt 200. The bulbous head region 270 and the radially protruding portions 260 may be formed from one piece (e.g., machined from a single piece). This component (or assembly of different components) can be connected or coupled by standard joining techniques to the shunt body 210 or another portion of the shunt 200. This component can be similar to or like a plug.

[0059]

[0072] The shunt delivery system 100 may include an inner wire 160 (mostly shielded) having an inner wire tip 162. The inner wire 160 may pass through the shunt 200 and emerge from an opening (shunt inlet opening 211) in the bulbous head region 270. Alternatively, the inner wire 160 may stop before protruding from the bulbous head region 270, with the stylet 165 (not shown) extending outward. A valley may be formed between the bulbous head region 270 and one of the radially protruding portions 260. Another valley may be formed between the radially protruding portions 260. When the dural sac 28 is punctured by the stylet 165 or inner wire 160, the bulbous head region 270 may be pushed through the opening so that the valley between the bulbous head region 270 and one of the radially protruding portions 260 is located transdurally across the distance of the opening in the dural sac 28. Alternatively, the shunt 200 can be pushed further so that one of the other valleys is transdurally located. One of the radially protruding portions 260 may function as an external anchor (e.g., similar to external anchor 250) outside of the dural sac 28. The outer diameter of the shunt 200 at the valley may be large enough that the dural sac 28 around the puncture exerts a force against the given transdurally located valley to provide support for fixation of the shunt 200.

[0060]

[0073] The bulbous head region 270 may function as an intradural anchor. According to an embodiment, the bulbous head region 270 is concave adjacent the dural sac 28.

[0074] 16A-16C, the shunt 200 can be implanted as follows: The guide catheter 110 can be positioned via an intravenous procedure. The shunt 200 can be delivered through the guide catheter 110 and via the shunt delivery system 100 through the venous system (such as into the intervertebral vein 22). Once the venous wall is reached, the stylet 165 can be advanced through the venous wall, the interstitial space 18, and the dural sac 28. The bulbous head region 270 can be advanced through the opening. Alternatively, the stylet 165 can puncture only the venous wall, after which the bulbous head region 270 can be advanced through an opening in the venous wall. Alternatively, after the stylet 165 punctures the dural sac 28, one or more regions of the puncture path (including the venous wall, the interstitial space 18, and the dural sac 28) can be expanded by an inflatable balloon (not shown). The balloon can be separate from the stylet 165 or can be part of the stylet 165. Once the bulbous head region 270 has moved through some or all of the interstitial space 18, the stylet 165 can be advanced again to puncture the dural sac 28. The bulbous head region 270 can then be advanced through an opening in the dural sac 28 and into the intradural space 30. The bulbous head region 270 and / or the radially protruding regions 260 can provide tactile feedback to the surgeon to indicate when one or more of the bulbous head region 270 and / or the radially protruding regions 260 have passed through the dural sac 28. The tactile feedback, in combination with the radiopaque markers 150 (which can be located on the bulbous head region 270, the radially protruding regions 260, and / or the valleys therebetween), can facilitate the surgeon in transdurally implanting the shunt 200 in the appropriate location. The radially protruding regions 260 can also limit the depth of insertion of the shunt into the intradural space 30. Once the shunt 200 is properly placed, the shunt delivery system 100 (including the stylet 165 and guide catheter 110) can be removed by the surgeon, leaving the shunt 200 in place.

[0061]

[0075] FIG. 12 shows a flowchart 400 of a method for implanting a shunt 200 intravenously, according to an embodiment. This method may be performed by a surgeon or a surgical robot. Some steps may be omitted. For example, the shunt 200 may not be removed from the patient. In step 402, the shunt 200 may be introduced into the patient's vascular system, for example, into a vein in the leg, neck, or arm. In step 404, an inlet region 211 of the shunt 200 may be positioned in at least one of an epidural vein 20 or an intervertebral vein 22. These veins 20, 22 may be located in the lumbar, thoracic, cervical, or sacral region. In step 406, the shunt 200 may be moved so that the inlet region 211 extends through the wall of the epidural vein 20 or intervertebral vein 22. In step 408, the shunt 200 may be moved so that the inlet region 211 extends into the interstitial space 18. In step 410, the limiter 140 may be at least partially deployed in the interstitial space 18, and the limiter 140 may determine the maximum length the shunt 200 may extend through the dural sac 28 and into the intradural space 30. Deploying the limiter 140 may include expanding the limiter 140 so that the outer diameter of the limiter 140 is greater than the outer diameter of the lateral region 215 of the shunt 200 between the inlet region 212 and the outlet region 214. In step 412, the shunt 200 may be moved so that the inlet region 212 extends at least partially through the dural sac 28 (including the arachnoid membrane). In step 414, an anchor 230 may be deployed within the intradural space 30 to stabilize the inlet region 212 of the shunt 200 relative to the dural sac 28. When the shunt 200 is positioned in its final location, the exit region 214 of the shunt 200 may be located in the epidural vein 20, the intervertebral vein 22, the periven- tal vein, or any suitable location along the venous pathway. The exit region 214 may also be positioned in the venous wall such that the exit opening 213 is in fluid communication with the venous pathway.

[0062]

[0076] In step 416, the shunt 200 can be removed later in a separate procedure, for example, if the shunt 200 becomes inoperable, non-functional, or is no longer needed. The shunt 200 may be removed from the patient by engaging a shunt removal feature on the shunt 200. To facilitate removal of the shunt 200, the outward radial force exerted by the fingers 231 may be no more than 90% of the tensile strength of the transverse stent body 215. This allows the shunt 200 to be withdrawn by being pulled through the dural sac 28 and into a catheter or sheath. In another embodiment, the tensile force required to collapse the fingers 231 (or any other anchor 230 type) when being pulled into a catheter or sheath or out of the dural sac 28 may be no more than 90% of the tensile strength of the transverse stent body 215. In another embodiment, a sheath can be pushed over the distal end of the shunt 200 to engage / cover the anchor 230 and partially or completely collapse it before being withdrawn.

[0063]

[0077] In embodiments of the donut-shaped anchors 230, the radially outward radial force exerted by the donut anchors 230 may be 90% or less of the tensile strength of the transverse stent body 215, which may facilitate withdrawal of the shunt 200 by being withdrawn through the dural sac 28. In another embodiment, the tensile force may be 90% or less of the tensile force of the transverse shunt body 215, which is required for the donut anchors 230 to stretch and subsequently collapse while being withdrawn into a catheter or sheath or out of the dural sac 28.

[0064]

[0078] According to embodiments, the proximal shunt region residing within the vein may include a radiopaque marker 150 for easy identification. The radiopaque marker 150 may be a material such as platinum / iridium or may be combined with the shunt outlet 213. The shunt outlet region 214 may include features (e.g., a catch or clasp) that allow the shunt 200 to be captured via a snare or a crushable snare similar to a "Chinese finger trap." The radiopaque marker 150 may include a relatively soft material, such as gold, that can be crushed to optionally seal the shunt 200. An external shunt anchor 250 similar to that shown in FIG. 9 may include the radiopaque marker 150 for identification and may also include features (e.g., a catch or clasp) for easy removal. A catheter, which may include a snare, catch, or clasp mechanism with a slidable sheath, may be advanced over the shunt body 210 for withdrawal (after the proximal end is snare). The shunt transverse body 215 may include features such as braided tubing to stop or reduce elongation of the shunt 200 during removal or sealing. The shunt transverse body 215 may also include reinforced plastic ribs in the tubing wall to also stop or reduce elongation. Such features can maintain substantial flexibility and kink resistance during withdrawal. The shunt transverse body 215 can be cut and removed from the distal shunt region, thus sealing and removing the distal shunt region.

[0065]

[0079] In another embodiment, the shunt inlet region 212 is similarly located in the intradural space 30, and the shunt body 210 is initially located in the venous line, but eventually traverses the venous wall such that the shunt outlet region 214 exits the body, which is connected to a valve 240 or a reservoir located under the skin. This embodiment may allow for the delivery of drugs directly into the CSF 32, repeated chemical and biological analysis of the CSF 32, measurement of the pressure of the CSF 32, and optional drainage of the CSF 32.

[0066]

[0080] According to embodiments, the puncture site in the thecal sac 28 and / or venous wall and / or interstitial space 18 can be dilated using a balloon (not shown) before implanting the shunt 200. Before advancing the shunt 200 through the shunt delivery system 100, a dilation system can be advanced through the guide catheter 110 to near the implantation site. A stylet 165 can extend through the dilation system. The stylet 165 can puncture the thecal sac 28, venous wall, and / or interstitial space 18 either once the dilation system is positioned or before the dilation system is positioned. After puncture, a deflated dilation balloon can be advanced across the puncture site. The dilation balloon can be advanced across multiple puncture sites at once or separately across selected puncture sites. The dilation balloon may have one or more radiopaque markers 150 embedded or attached thereto. Once the dilation balloon is properly positioned at the puncture site, the surgeon can inflate the dilation balloon to the appropriate diameter to widen the opening at the puncture site. After the tissue has been dilated, the dilation balloon may be deflated, again under the control of the surgeon. The dilation balloon, and any other components of the dilation system, may be removed from the patient via the guide catheter 110. The shunt 200 may then be introduced over the stylet 165, and the shunt 200 may be implanted as described herein.

[0067]

[0081] In an embodiment related to the previous embodiment, the dilatation balloon may be part of the stylet 165. The dilatation balloon may have a length of 0.5 to 2 cm and may be inflated to this length. After piercing the venous wall, the stylet 165 may pierce the interstitial space 18 and perforate the dural sac 28. The dilatation balloon of the stylet 165 may then be inflated and subsequently deflated. The shunt 200 may then be advanced over the stylet 165. The stylet 165 may then be removed, leaving the shunt 200 in place at the implanted location. Parts List Part Reference Number spinal canal 10 Bone 12 Nerve 14 Nerve root 16 fat, interstitial space 18 Epidural vein 20 Intervertebral vein 22 lumbar vein 26 Dural sac 28 Intradural space 30 Cerebrospinal fluid 32 Shunt delivery system 100 Guide catheter 110 Guidewire 120 Stabilizer 130 Limiter 140 Radiopaque marker 150 Internal Wire 160 Internal wire shoulder 161 Internal Wire Tip 162 Stylet 165 Sheath 170 Spring 180 Shunt 200 Shunt body 210 Shunt inlet opening 211 Shunt entrance area 212 Shunt outlet opening 213 Shunt outlet area 214 Shunt lateral area 215 Crushable area 216 Reinforcement 220 Anchor (intradural anchor) 230 Anchor Finger 231 Anchor Wire 232 Valve (yellow in Figure 11) 240 External (epidural) anchor 250 Radial projected area 260 Bulbous head area 270

[0082] It will be understood by those skilled in the art that various changes may be made and equivalents substituted without departing from the scope of the novel technology disclosed in this application. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the novel technology without departing from its scope. Therefore, it is intended that the novel technology not be limited to the particular technology disclosed, but rather to include all technology falling within the scope of the appended claims.

Claims

1. 1. A method of positioning a cerebrospinal fluid shunt in a patient's vein, comprising: introducing the cerebrospinal fluid shunt into the patient's vascular system, the cerebrospinal fluid shunt including an inlet opening at an inlet region and an outlet opening at an outlet region, the inlet opening and the outlet opening being in fluid communication with each other; positioning the entry region of the cerebrospinal fluid shunt into an epidural or intervertebral vein; puncturing the wall of the epidural or intervertebral vein, crossing the interstitial space, and puncturing the dural sac with a stylet, the stylet including a wire extending through the cerebrospinal fluid shunt; moving the cerebrospinal fluid shunt so that the entry area extends through the wall of the epidural or intervertebral vein; after the step of moving the cerebrospinal fluid shunt so that the entrance area extends through the wall of the epidural vein or the intervertebral vein, moving the cerebrospinal fluid shunt so that the entrance area extends into the interstitial space; After the step of moving the cerebrospinal fluid shunt so that the inlet region extends into the interstitial space, moving the cerebrospinal fluid shunt so that the inlet region extends through the dural sac so that the inlet region of the cerebrospinal fluid shunt is positioned in the intradural space and the outlet region of the cerebrospinal fluid shunt is positioned in a venous line; A method comprising:

2. 10. The method of claim 1, The method, wherein the epidural vein or the intervertebral vein is located in the patient's lumbar region.

3. 10. The method of claim 1, The method, wherein the epidural vein or the intervertebral vein is located in the patient's chest.

4. 10. The method of claim 1, The method, wherein the epidural vein or the intervertebral vein is located in the patient's neck.

5. 10. The method of claim 1, The method, wherein the epidural vein or the intervertebral vein is located in the patient's sacrum.

6. 10. The method of claim 1, The method of claim 1, wherein the venous pathway in which the outlet opening of the cerebrospinal fluid shunt is located comprises at least one of an epidural vein, an intervertebral vein, a paravertebral vein, a lumbar vein, an iliac vein, a femoral vein, an azygos vein, a hemiazygos vein, an inferior vena cava, a superior vena cava, the right atrium of the heart, or a venous tributary of the inferior vena cava or the superior vena cava.

7. 10. The method of claim 1, The method further comprises, after the step of puncturing the dural sac, deploying an anchor within the intradural space to stabilize the entrance region of the cerebrospinal fluid shunt relative to the dural sac.

8. 10. The method of claim 1, The method further includes, prior to the step of puncturing the dural sac, deploying a limiter at least partially into the interstitial space, the limiter determining a maximum length of the cerebrospinal fluid shunt extending through the dural sac into the intradural space.

9. 9. The method of claim 8, The method, wherein the step of deploying a limiter comprises expanding the limiter such that an outer diameter of the limiter is greater than an outer diameter of a lateral region of the cerebrospinal fluid shunt between the inlet region and the outlet region.

10. 10. The method of claim 1, A method in which, when the entrance region of the cerebrospinal fluid shunt is located in the intradural space, the exit region of the cerebrospinal fluid shunt is located in one of an epidural vein, an intervertebral vein, a lumbar vein, an iliac vein, or a perivenpal vein.

11. 10. The method of claim 1, The method, wherein the cerebrospinal fluid shunt comprises silicone.

12. 10. The method of claim 1, The method, wherein the cerebrospinal fluid shunt comprises polyurethane.

13. 10. The method of claim 1, The method, wherein the cerebrospinal fluid shunt comprises nitinol.

14. 10. The method of claim 1, The method, wherein the cerebrospinal fluid shunt comprises at least one radiopaque marker.

15. 10. The method of claim 1, The method, wherein the cerebrospinal fluid shunt includes a material configured to reduce at least one of blood clotting, protein aggregation, or cell aggregation on at least one of an exterior of the cerebrospinal fluid shunt or an interior of the inlet region.

16. 10. The method of claim 1, The cerebrospinal fluid shunt includes an anti-reflux mechanism between the inlet opening and the outlet opening, the anti-reflux mechanism configured to reduce or prevent retrograde movement of blood.

17. 10. The method of claim 1, The cerebrospinal fluid shunt includes a flow regulator between the inlet opening and the outlet opening, the flow regulator configured to regulate the flow of cerebrospinal fluid between the inlet opening and the outlet opening.

18. 10. The method of claim 1, The method, wherein the step of introducing the cerebrospinal fluid shunt into the patient's vascular system comprises introducing the cerebrospinal fluid shunt into a leg vein, a neck vein, or an arm vein.

19. 10. The method of claim 1, The method further includes the step of detaching the cerebrospinal fluid shunt by engaging a shunt detachment feature of the cerebrospinal fluid shunt.

20. 10. The method of claim 1, The method further includes temporarily enlarging at least one of the opening through one of the walls of the epidural vein or the intervertebral vein, a region of the interstitial space, or the opening through the dural sac at at least one enlarged location by positioning a balloon at the at least one enlarged location and inflating the balloon to enlarge the at least one enlarged location before or during passage of the shunt.

21. 1. A cerebrospinal fluid shunt for placement within a patient, comprising: an entrance region configured to pass through an opening in an epidural venous wall or an intervertebral venous wall, pass through an opening in a dural sac, and pass through an interstitial space between either the epidural venous wall or the intervertebral venous wall and the dural sac; an inlet opening in the inlet region configured to receive cerebrospinal fluid from the intradural space; an exit region configured to be positioned in the venous line; an outlet opening at the outlet region, the outlet opening in fluid communication with the inlet opening, the outlet opening configured to allow the cerebrospinal fluid received by the inlet region to flow out of the cerebrospinal fluid shunt; a lateral region between the inlet region and the outlet region, the lateral region including a channel allowing fluid communication between the inlet opening and the outlet opening; an insertion limiting portion located in the lateral region, the insertion limiting portion configured to be positioned in the interstitial space between the epidural venous wall or the intervertebral venous wall and the dural sac; A cerebrospinal fluid shunt comprising:

22. 22. The cerebrospinal fluid shunt of claim 21, at least one radiopaque marker located at least partially in the entrance region; at least one radiopaque marker located at least partially in the lateral region; at least one radiopaque marker located at least partially in the exit area; The cerebrospinal fluid shunt further comprises:

23. 23. The cerebrospinal fluid shunt of claim 22, The cerebrospinal fluid shunt, wherein the inlet region includes a bulbous head region.

24. 24. The cerebrospinal fluid shunt of claim 23, A cerebrospinal fluid shunt, wherein the insertion limiting portion includes a radially protruding portion, and the bulbous head region and the radially protruding portion are integrated into one piece.

25. 25. The cerebrospinal fluid shunt of claim 24, A cerebrospinal fluid shunt, wherein the one component is in communication with another portion of the cerebrospinal fluid shunt that includes the outlet region.

26. 1. A system for positioning a cerebrospinal fluid shunt in a patient, comprising: a guide catheter configured to slide over a proximal region of a guidewire positioned in the patient's venous system, the guide catheter including a proximal region and a distal region, the guide catheter including an anchor configured to secure the distal region of the guide catheter in position within the patient's venous system; an adapter coupled to the proximal region of the guide catheter, the adapter configured to selectively prevent fluid from the patient from passing out of the adapter; a sheath including a proximal region and a distal region, the sheath being positioned at least partially within the guide catheter; a shunt positioned at least partially between the guide catheter and the sheath, the shunt including an inlet region including an inlet opening, an outlet region including an outlet opening, and a lateral region between the inlet region and the outlet region, the lateral region including a channel such that the inlet opening is in fluid communication with the outlet opening, the lateral region configured to extend through a venous wall and through an interstitial space, the inlet region configured to extend through a dural sac into an intradural space, and the outlet region configured to be positioned in a venous access; a wire configured to extend through the shunt and at least partially exit the inlet opening, the wire including a proximal region and a distal region, the distal region configured to puncture the venous wall and the dural sac; A system comprising:

27. 27. The system of claim 26, The system, wherein the anchor of the guide catheter includes a balloon.

28. 27. The system of claim 26, The system, wherein the inlet region of the shunt further includes an anchor configured to stabilize the inlet region relative to the dural sac.

29. 27. The system of claim 26, The system, wherein the sheath comprises a retractable sheath.

30. 27. The system of claim 26, The system, wherein the lateral region includes a limiter configured to limit an insertion distance of the shunt into the patient.

31. 1. A method of positioning a cerebrospinal fluid shunt in a patient's vein, comprising: introducing the cerebrospinal fluid shunt into the patient's vascular system, the cerebrospinal fluid shunt including an inlet opening at an inlet region and an outlet opening at an outlet region, the inlet opening and the outlet opening being in fluid communication with each other; positioning the entry area of ​​the cerebrospinal fluid shunt in an epidural or intervertebral vein; After positioning the inlet region of the cerebrospinal fluid shunt in the epidural vein or the intervertebral vein, moving the cerebrospinal fluid shunt so that the inlet region extends into the interstitial space; After the step of moving the cerebrospinal fluid shunt so that the inlet region extends into the interstitial space, moving the cerebrospinal fluid shunt so that the inlet region passes through an opening in a thecal sac so that the inlet region of the cerebrospinal fluid shunt is positioned at least partially in the intradural space and the outlet region of the cerebrospinal fluid shunt is positioned in a venous line; A method comprising:

32. 1. A method of positioning a cerebrospinal fluid shunt in a patient's vein, comprising: introducing the cerebrospinal fluid shunt into the patient's vascular system, the cerebrospinal fluid shunt including an inlet opening at an inlet region and an outlet opening at an outlet region, the inlet opening and the outlet opening being in fluid communication with each other; positioning the entry area of ​​the cerebrospinal fluid shunt in an epidural or intervertebral vein; moving the cerebrospinal fluid shunt so that the entry area passes through an opening in the wall of the epidural or intervertebral vein; After the step of moving the cerebrospinal fluid shunt so that the inlet region passes through the wall of the epidural vein or the intervertebral vein, moving the cerebrospinal fluid shunt so that the inlet region passes through an opening in a thecal sac so that the inlet region of the cerebrospinal fluid shunt is positioned at least partially within the intradural space and the outlet region of the cerebrospinal fluid shunt is positioned in a venous line; A method comprising:

33. 1. A method of positioning a cerebrospinal fluid shunt in a patient's vein, comprising: introducing the cerebrospinal fluid shunt into the patient's vascular system, the cerebrospinal fluid shunt including an inlet opening at an inlet region and an outlet opening at an outlet region, the inlet opening and the outlet opening being in fluid communication with each other; positioning the entry area of ​​the cerebrospinal fluid shunt in an epidural or intervertebral vein; moving the cerebrospinal fluid shunt so that the entry area extends through the wall of the epidural or intervertebral vein; after the step of moving the cerebrospinal fluid shunt so that the entrance area extends through the wall of the epidural vein or the intervertebral vein, moving the cerebrospinal fluid shunt so that the entrance area extends into the interstitial space; After the step of moving the cerebrospinal fluid shunt so that the inlet region extends into the interstitial space, moving the cerebrospinal fluid shunt so that the inlet region extends through the dural sac so that the inlet region of the cerebrospinal fluid shunt is positioned in the intradural space and the outlet region of the cerebrospinal fluid shunt is in fluid communication with at least one of a reservoir or a percutaneous port positioned under the patient's skin; A method comprising:

34. 34. The method of claim 33, The method, wherein the percutaneous port is configured to at least one of deliver a drug to the patient, allow for the drainage of CSF, or facilitate the measurement of CSF pressure.

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