US20100191168A1 - Endovascular cerebrospinal fluid shunt - Google Patents

Abstract

An implantable shunt device for draining cerebrospinal fluid from a patient's subarachnoid space. The device includes a shunt having opposed first and second ends. A one-way valve is located at the first end of the shunt. A helical tip is disposed at the second end. The helical tip is constructed to penetrate a sinus wall of the patient. Upon implantation, a hollow passageway extends between the helical tip and one-way valve such that fluid can be drained through the helical tip and out through the valve. The endovascular cerebrospinal fluid shunt of the present invention can be placed into a patient percutaneously via a catheter inserted into the venous system of the body through a needle hole, without the need for open surgery and the skin incisions required with current shunt devices. The device also allows for more physiologic drainage of cerebrospinal fluid since the device is shunting cerebrospinal fluid into the same cerebral venous system that occurs naturally in normal people.

Description

BACKGROUND OF THE INVENTION
• 1. Field of the Invention
• The present invention relates to an endovascular shunt implantable into the wall of a patient's sigmoid sinus, and more particularly, to a shunt capable of draining cerebrospinal fluid from the patient's subarachnoid space to the venous system.
• 2. Description of the Related Art
• It is known to treat hydrocephalus by draining cerebrospinal fluid (CFS) from the brain with a drain tube, catheter or shunt. See U.S. Pat. Nos. 5,385,541 and 4,950,232. These known devices are complex and invasive. The risk for infection is also increased due to the complexity of these devices.
• The known shunts are limited to areas of placement due to fluid flow control. Moreover, the known shunts and methods of placements do not work in conjunction with a body's natural disease control processes. Accordingly, in recent years exploration of placement of a catheter or shunt in the venous sinus of a patient has been explored. See U.S. Pat. No. 6,283,934 and Published Application No. 2005/0256510.
• However, fluid flow still poses difficulties due to the complexity of the devices and the placement areas. Commonly, the shunts/catheters are placed through the skull of the patient requiring pressure control to facilitate CSF flow and also creating a dangerous infection site.
• Thus, there is a need for an endovascular shunt that can be inserted into the venous system percutaneously.
SUMMARY OF THE INVENTION
• The present invention relates to an endovascular CSF shunt that drains CSF from the cistern around the cerebellum into the sigmoid sinus lumen.
• The present invention also relates to a method of draining CSF by inserting, deploying and detaching the shunt of the present invention by an endovascular route through the venous system. The venous system is accessed either through the femoral vein or the jugular vein percutaneously.
• The endovascular cerebrospinal fluid shunt of the present invention is an improvement over the standard cerebrospinal fluid shunts because it can be placed into a patient percutaneously via a catheter inserted into the venous system of the body through a needle hole, without the need for open surgery and the skin incisions required with current shunt devices. In some patients, the device can be inserted without general anesthesia, which is not possible with current cerebrospinal fluid shunts. The device also will allow for more physiologic drainage of cerebrospinal fluid since the device is shunting cerebrospinal fluid into the same cerebral venous system that occurs naturally in normal people.
• One aspect of the present invention is to provide an implantable shunt device for draining fluid from a patient's subarachnoid space. The device includes a shunt having opposed first and second ends. A one-way valve is located at the first end of the shunt and a helical tip is disposed at the second end. The helical tip penetrates the sigmoid sinus wall of the patient and a hollow passageway extending between the helical tip and the CSF cistern allows the CSF to be drained through the helical tip and out through the valve.
• Another aspect of the present invention provides a method for draining cerebrospinal fluid from a patient's subarachnoid space, the method includes the steps of providing a shunt having opposed first and second ends, delivering the shunt to the sinus wall, implanting the helical tip in the sinus wall of the patient; and draining cerebrospinal fluid from the patient.
• These and other features, aspects, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiment relative to the accompanied drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a top cross-sectional view of a human skull illustrating the placement of the shunt of the present invention.
• FIG. 2 is a partial cross-section of an embodiment of the endovascular shunt of the present invention.
• FIG. 3 is a partial view of delivering the endovascular shunt of the present invention to the CSF space of a patient's venous system.
• FIG. 4 is a partial view of the implantation of the endovascular shunt of the present invention into the sigmoid sinus wall.
• FIG. 5 is a partial view of the endovascular shunt of the present invention implanted in the sigmoid sinus wall.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
• Referring toFIG. 1, the endovascular shunt device of the present invention can be delivered to the right orleft sigmoid sinus12A,12B of a patient'sskull10 via either the right or left jugular vein respectively of the venous system. Thesigmoid sinus lumen12 is located between the temporal bone (FIGS. 3-5) and the cerebellum.
• Ashunt20 is implanted into asigmoid sinus wall16, so that one end communicates with CSF located in the cistern orCSF space18 around thecerebellum19. The device of the present invention uses the body's natural disease control mechanisms by delivering the CSF fromcistern18 intosigmoid sinus lumen12 of the venous system. The venous system of the patient can be accesses either through the femoral or jugular veins (not shown) percutaneously. It should be appreciated that the shunt device of the present invention can be delivered to the sigmoid sinus via other locations.
• As shown inFIG. 2, one embodiment of theendovascular CSF shunt20 of the present invention includes opposed first andsecond ends22,24. A one-way valve26 is located atfirst end22. As will be described further herein, CSF can travel throughshunt20 and outend22, however, other fluid cannot enter the shunt fromopen end22.
• Ahelical tip30 is located atsecond end24. As will be described further herein,helical tip30 has a closed sharpenedend31 that is adapted to penetratesinus wall16.Tip30 includes a plurality ofapertures34 through which the CSF enters the tip. Ahollow passageway32 extends fromtip30 andopen end22, such that the CSF fluid entering throughapertures34 can pass throughvalve26 and pass from anoutlet36.
• Referring toFIGS. 3-5 and as described above, adelivery catheter40 is delivered to the venous system via the femoral or jugular vein.Catheter40 is inserted intosigmoid sinus lumen12 at aproximal location13 toward the neck and inserted toward adistal end15, which is toward the brain.
• Delivery catheter40 includes asecond lumen44 and ashunt delivery port42.Lumen44 directs the entire catheter to the correct location with for example, a guide wire, to allow injection of intravenous contrast to visualize the venous lumen.Lumen44 also supportsballoons46 that can be deployed to occlude venous flow during stunt implantation. Shunt20 is positioned at an end of aninternal catheter48 that is manipulated throughcatheter40 andport42. To prevent thrombosis within the sigmoid sinus and around the endovascular shunt,shunt20 can be provided with anantithrombic coating38
• As shown inFIG. 4,internal catheter48 facilitates twisting ofshunt20 so that it penetrates throughsigmoid sinus wall12.Catheter48 includes a hollow lumen to allow CSF withdrawal after shunt penetration of the sigmoid sinus wall to confirm that CSF is flowing through the shunt. However, it must be rigid enough to allow twisting of the shunt such that it penetrates the sigmoid sinus wall. Upon insertion,helical tip30 extends intocistern18 and CSF located therein. Aprojection28 located onshunt20 between the ends abuts the wall and prevents the shunt from passing therethrough. Upon placement,internal catheter48 is detached. The CSF can also be aspirated back prior to detachment ofcatheter48.
• Thereafter,delivery catheter40 can be removed and shunt20 is implanted as shown inFIG. 5.CSF50 draining fromoutlet36 fromCSF space18 is delivered to thevenous blood flow17 and removed. It should be appreciated that other means of fluid removal can communicate withshunt20 to direct the CSF as desired. It also should be appreciated that shunt20 can incorporate different tips atend24.
• Thus, the endovascular cerebrospinal fluid shunt of the present invention can be placed into a patient percutaneously via a catheter inserted into the venous system of the body through a needle hole, without the need for open surgery and the skin incisions required with current shunt devices. In some patients, the device can be inserted without general anesthesia, which is not possible with current cerebrospinal fluid shunts. The device also will allow for more physiologic drainage of cerebrospinal fluid since the device is shunting cerebrospinal fluid into the same cerebral venous system that occurs naturally in normal people.
• Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims.

Claims (6)

1. An implantable shunt device for draining cerebrospinal fluid from a patient's subarachnoid space, the device comprising:

a shunt having opposed first and second ends;

a one-way valve located at the first end of the shunt;

a helical tip disposed at the second end, said helical tip being constructed to penetrate a sinus wall of the patient; and

a hollow passageway extending between the helical tip and one-way valve such that cerebrospinal fluid can be drained through the helical tip and out through the valve.

2. The shunt ofclaim 1, wherein the helical tip includes a plurality of apertures into which the cerebrospinal fluid enters the tip.

3. The shunt ofclaim 1, wherein the shunt includes an antithrombic coating.

4. An implantable system for draining cerebrospinal fluid from a patient's subarachnoid space, the system comprising:

a shunt having opposed first and second ends, a one-way valve located at the first end of the shunt, and a helical tip disposed at the second end, said helical tip being constructed to penetrate a sinus wall of the patient, wherein the first and second ends are in fluid communication to enable the cerebrospinal fluid to be drained through the helical tip and out through the valve; and

a catheter for delivering and implanting the shunt into the sinus wall.

5. A method for draining cerebrospinal fluid from a patient's subarachnoid space, the method comprising the steps of:

providing a shunt having opposed first and second ends, a one-way valve located at the first end of the shunt, and a helical tip disposed at the second end, said helical tip being constructed to penetrate a sinus wall of the patient, wherein the first and second ends are in fluid communication to enable the cerebrospinal fluid to be drained through the helical tip and out through the valve;

delivering the shunt to the sinus wall;

implanting the helical tip in the sinus wall of the patient; and

draining cerebrospinal fluid from the patient.

6. An implantable shunt device for draining fluid from a patient's subarachnoid space, the device comprising:

a shunt having opposed first and second ends;

a one-way valve located at the first end of the shunt; and

a helical tip disposed at the second end, said helical tip being constructed to penetrate tissue of the patient; and

a hollow passageway extending between the helical tip and one-way valve such that fluid can be drained through the helical tip and out through the valve.

Images