SUBARACHNOID EPIDURAL SHUNT
Methods and devices are provided for shunting fluid to treat hydrocephalous, and in particular for treating normal pressure hydrocephalous, or Alzheimer's, Idiopathic Intracranial Hypertension (IIH), or any other condition in which it is necessary to drain and/or cleanse CSF. The methods and devices utilize a shunt having an inlet port, and outlet port, and a flow control component for controlling fluid flow from the inlet port to the outlet port. The shunt can be implanted at a location along or within a patient's spinal column. In one exemplary embodiment, an inlet port of a shunt can be implanted within the subarachnoid space, and an outlet port of a shunt can be implanted at a drainage site. In certain exemplary embodiments, the cerebrospinal fluid is drained into the epidural space.
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The present invention claims priority to U.S. Provisional Application No. 60/668,111, filed on Apr. 5, 2005 and entitled “Subarachnoid-Epidural Shunt,” and U.S. Provisional Application No. 60/703,470, filed on Jul. 29, 2005 and entitled “Subarachnoid-Epidural Shunt and Improved CSF Diversion Devices and Methods,” which are hereby incorporated by reference in their entireties.
FIELD OF THE INVENTIONThe present invention relates to methods and devices for shunting cerebrospinal fluid.
BACKGROUND OF THE INVENTIONMany conditions benefit from shunting, removal, or cleansing of CSF, including hydrocephalus, pseudotumor cerebri (Idiopathic Intracranial Hypertension, IIH), and Alzheimer's disease. Hydrocephalus, for example, is a condition afflicting patients who are unable to regulate cerebrospinal fluid flow through their body's own natural pathways. Produced by the ventricular system, cerebrospinal fluid (CSF) is normally absorbed by the body's venous system. In a patient suffering from hydrocephalus, the cerebrospinal fluid is not absorbed in this manner, but instead accumulates in the ventricles of the patient's brain and can lead to serious medical conditions.
Hydrocephalus exists in two forms: communicating (non-obstructive hydrocephalus) caused by inadequate absorption of CSF when the ventricular pathways are not obstructed; and non-communicating (obstructive hydrocephalus) caused by blockage in the ventricular pathways through which CSF flows. Hydrocephalus can also be either congenital, where the condition is present at birth or detected soon thereafter, or acquired, where the condition is acquired as the result of infection, head trauma, brain tumors, cysts, etc. Normal pressure hydrocephalus (NPH) is a type of communicating (non-obstructive) hydrocephalous that occurs in adults, usually older adults. The drainage of CSF is blocked gradually, and the excess fluid builds up slowly. With NPH it is believed that the ventricles enlarge to handle the increased volume of the CSF, and the compression of the brain from within by the fluid-filled ventricles destroys or damages brain tissue causing some of the symptoms. Unlike other types of Hydrocephalus that typically result in increased pressure in the head when too much CSF accumulates, NPH shows little to no increased pressure, thus leading to the name “Normal Pressure Hydrocephalus.”
NPH can be treated by draining the excess fluid from the ventricular system to another area of the patient's body, such as the abdomen or vascular system, where it can be reabsorbed into the bloodstream. A drainage system, commonly referred to as a shunt, is often used to carry out the transfer of fluid. It consists of a system of catheters with a flow control component to control fluid drainage and prevent back-flow. In order to install the shunt, typically a scalp incision is made and a small hole is drilled in the skull. Current shunts used to treat NPH are inserted surgically so that the upper end is in communication with the ventricular system. Since NPH is non-obstructive, the upper end or proximal catheter of the shunt can be placed either in the ventricles (ventricular catheter) or in the sub-arachnoid space at the level of the lumbar spinal column (lumbar catheter). The lower end or distal catheter of the shunt can lead into the abdomen (ventriculo-peritoneal shunt), wherein it passes into the bloodstream. There are several other body cavities available for distal drainage of a shunt. When shunts were first introduced, a one-way valve drained spinal fluid directly into the right atrium of the heart via the jugular vein (ventriculoatrial shunt). Vascular shunts functioned very well, but they were prone to multiple problems including early and late infection, as well as rare, potentially fatal heart failure due to blockage of blood vessels within the lungs by particles of blood clot flaking off the shunt's catheter tip. The use of the heart has been largely abandoned as an initial choice because of these problems but it remains a viable second option when infection or surgery has rendered the abdominal cavity unaccommodating of the distal shunt catheter. The chest cavity is another cavity which can be used as a backup to the abdominal cavity (ventriculopleural shunt). The catheter is placed inside the rib cage between its inner lining and the outer lining of the lungs. Occasionally, this cavity cannot resorb the CSF rapidly and the lung becomes compressed by the excess CSF resulting in difficulty in breathing. The catheter must be moved to a different cavity is such cases. Rarely, the catheter can rest on the diaphragm (the muscle at the base of the lungs used for breathing), causing irritation and hiccups.
While shunts were a major medical breakthrough, there are problems that still remain unsolved in the treatment of hydrocephalus, including shunt obstruction, infection, and overdrainage. Shunted NPH only has a success rate of about 50%. These same problems also exist with other conditions which are treated by CSF diversion, such as pseudotumor cerebri.
Accordingly, there remains a need for improved methods and devices for draining CSF to treat hydrocephalous, pseudotumor cerebri (IIH), or any other condition in which it is necessary to drain and/or cleanse CSF, potentially including Alzheimer's Disease.
SUMMARY OF THE INVENTIONMethods and devices are provided for shunting fluid, such as CSF. In one embodiment, a shunt device is provided and includes a housing having a fluid inlet port and a fluid outlet port. The fluid inlet and outlet ports are spaced a distance apart such that the fluid inlet port can be positioned to receive fluid from a source of cerebrospinal fluid, such as a subarachnoid space of a spinal column, and the fluid outlet port can be positioned to deliver fluid to a body cavity capable of accommodating cerebrospinal fluid drainage, such as an epidural space of a spinal column. The housing can also include a flow control component disposed therein and in fluid communication with the fluid inlet and outlet ports for controlling fluid flow from the fluid inlet port to the fluid outlet port.
The housing can have a variety of configurations, but in one embodiment the housing can include an elongate member extending therefrom and adapted to be disposed within a bone hole. The elongate member can have a variety of configurations, and it can include a first lumen in fluid communication with the fluid inlet port, and optionally a second lumen in fluid communication with the fluid outlet port. The elongate member can include other features, such as an external surface that is adapted to facilitate bone in-growth into the elongate member. For example, the elongate member can include bone-engaging surface features or a surface coating. In other embodiments, the device can also include a sleeve that is removably disposed around the elongate member and that is adapted to be disposed within a bone hole to anchor the elongate member within the bone hole. The sleeve can include a flange formed on a terminal end thereof and adapted to abut against a bone surface. The sleeve can also include a mating element formed on an inner surface thereof and adapted to removably mate to a complementary mating element formed on an outer surface of the elongate member.
In another embodiment, the housing can include a central portion that is adapted to be disposed within a lumen, and opposed first and second ends that are adapted to be positioned adjacent to opposed ends of the lumen to anchor the central portion within the lumen. The fluid inlet port can be formed in the first end of the housing and the fluid outlet port can be formed in the second end of the housing. The central portion can have a variety of configurations, but in one exemplary embodiment it can have a substantially cylindrical shape that is configured to be disposed within a substantially cylindrical lumen. The flow control component can be disposed within an inner lumen or bore formed in the central portion, or the bore can form the flow control component and it can have a diameter that is effective to control fluid flow therethrough. The first and second ends of the housing can also have a variety of configurations, but in one embodiment the first and second ends of the housing can be expandable.
In other aspects, a shunt system is provided having a shunt with first and second catheters and a flow control component coupled therebetween for controlling fluid flow from the first catheter to the second catheter. The system also includes a dual-lumen cannula having first and second lumens extending therethrough for respectively receiving the first and second catheters. The first lumen can have an opening that is positioned a distance apart from an opening in the second lumen such that the opening in the first lumen can be positioned to receive fluid from a subarachnoid space in a spinal column and the opening in the second lumen can be positioned to deliver fluid to an epidural space in a spinal column. In an exemplary embodiment, a portion of the first lumen adjacent to the opening is curved to guide the first catheter into the subarachnoid space, and a portion of the second lumen adjacent to the opening is curved to guide the second catheter into the epidural space.
Methods for shunting fluid are also provided, and in one embodiment the method can include positioning an inlet port of a shunt to receive fluid from a subarachnoid space in a spinal column, and positioning an outlet port of the shunt to deliver fluid to an epidural space of the spinal column such that fluid is drained from the subarachnoid space into the epidural space. While the shunt can have various configurations, one exemplary shunt includes a flow control component in fluid communication with the inlet and outlet ports for controlling fluid flow from the inlet port to the outlet port. The inlet port can be formed in a terminal end of a first catheter coupled to the flow control component, and the outlet port can be formed in a terminal end of a second catheter coupled to the flow control component. Positioning the inlet port can include forming a hole through a dura mater into the subarachnoid space and positioning at least a portion of the shunt through the hole in the dura mater to position the inlet port to receive fluid from the subarachnoid space, and positioning the outlet port can include forming a bone hole through a lamina into the epidural space and positioning at least a portion of the shunt through the bone hole in the lamina to position the outlet port to deliver fluid to the epidural space. In an exemplary embodiment, the shunt can include an elongate member and the inlet port can extend into a first lumen in the elongate member and the outlet port can extend into a second lumen in the elongate member. The elongate member can be inserted through the bone hole in the lamina. Inserting the elongate member can include threadably mating the elongate member to a sleeve positioned within the bone hole in the lamina. In other embodiments, positioning the inlet and outlet ports can include inserting a dual-lumen cannula through tissue to position an open end of a first lumen of the member within the epidural space, and to position an open end of a second lumen of the member within the subarachnoid space, and inserting a first catheter through the first lumen to position an end of the first catheter within the epidural space, and inserting a second catheter through the second lumen to position an end of the second catheter within the subarachnoid space.
The method can further include anchoring the flow control component adjacent to the spinal column. For example, the flow control component can be anchored to a vertebra. Exemplary anchoring locations include the spinous process of a vertebra. In other embodiments, the flow control component can be anchored to soft tissues surrounding a vertebra.
In yet another embodiment, a method of shunting fluid is provided and includes positioning an inlet port of a shunt at a location within a patient's body in which cerebrospinal fluid can flow into the inlet port, and anchoring a flow control component of the shunt to at least one of a vertebra and soft tissue surrounding a vertebra. The flow control component is disposed between the inlet port and an outlet port of the shunt for controlling cerebrospinal fluid flow from the inlet port to the outlet port. The method further includes positioning the outlet port of the shunt at a location within the patient's body in which cerebrospinal fluid flowing from the outlet port can be drained. In certain exemplary embodiments, the flow control component can be anchored to a location on a vertebra, such as of a spinous process, a lamina, and a transverse process.
BRIEF DESCRIPTION OF THE DRAWINGSThe invention will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
Certain exemplary embodiments will now be described to provide an overall understanding of the principles of the structure, function, manufacture, and use of the devices and methods disclosed herein. One or more examples of these embodiments are illustrated in the accompanying drawings. Those of ordinary skill in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments and that the scope of the present invention is defined solely by the claims. The features illustrated or described in connection with one exemplary embodiment may be combined with the features of other embodiments. Such modifications and variations are intended to be included within the scope of the present invention.
The present invention provides methods and devices for shunting fluid to treat hydrocephalous, and in particular NPH, or Alzheimer's, Idiopathic Intracranial Hypertension (IIH), or any other condition in which it is necessary to drain and/or cleanse CSF. In general, the methods utilize a shunt that includes an inlet port, an outlet port, and a flow control component for controlling fluid flow from the inlet port to the outlet port. Exemplary shunts will be discussed in more detail below. The shunt can be implanted at a location along or within a patient's spinal column.
As further shown in
While
The shunt can also be implanted using a variety of techniques. In one exemplary embodiment, shown in
In other embodiments, rather than anchoring a flow control component to the vertebra or soft tissues and extending catheters into or adjacent to the epidural and subarachnoid spaces E, S, the shunt can be configured to be anchored directly to the lamina, or to be implanted in the epidural space E or in the dura mater D between the epidural and subarachnoid spaces E, S.
In the embodiment shown in
In order to allow fluid to flow through the shunt 30, the lumens 38, 39 can be in fluid communication with a flow control component 36 disposed therebetween. As shown in
In use, referring to
In order to position the inlet and outlet ports 38i, 39o in or adjacent to the subarachnoid and epidural spaces S, E, the elongate member 34 needs to extend through the dura mater D which is located between the subarachnoid and epidural spaces S, E. In one embodiment, shown in
Once the shunt 30 is implanted, as shown in
In use, as with the embodiment shown in
A person skilled in the art will appreciate that particular method of implanting the shunt will vary depending on the particular configuration of the shunt, and whether it includes one, two, or three pieces. For example, referring to the shunt 30 of
As indicated above, in other embodiments a shunt can be implanted within the dura mater D between the subarachnoid and epidural spaces S, E.
In use, as shown, the shunt 70 is implanted within the epidural space E, and the elongate member 74 is positioned through the dura mater D such that the inlet port 74i is disposed adjacent to or within the subarachnoid space S. As previously explained, various devices known in the art can be used to penetrate through the dura mater D and/or guide the elongate member 74 therethrough, or the elongate member 74 can include a tissue-penetrating tip formed thereon. In order to anchor the shunt 70 within the epidural space E, the elongate member 74 can include surface features and/or coatings formed or disposed thereon to prevent removal thereof from the dura mater D, or the housing 72 can be attached to the dura mater D using sutures, bone screws, or other mating techniques. Once the shunt 70 is implanted, CSF can flow from the subarachnoid space S through the shunt 70, where it is released in a controlled manner into or adjacent to the epidural space E.
The shunt 80 can also include an anchor member formed on or coupled each end thereof for anchoring the shunt 80 within the dura mater D. The anchor members can have a variety of configurations, but in an exemplary embodiment the anchor members are expandable. For example, each anchor member can be in the form of an expandable balloon. In the embodiment shown in
One skilled in the art will appreciate further features and advantages of the invention based on the above-described embodiments. Accordingly, the invention is not to be limited by what has been particularly shown and described, except as indicated by the appended claims. All publications and references cited herein are expressly incorporated herein by reference in their entirety.
Claims
1. A shunt device, comprising:
- a housing having at least a portion configured to be disposed within a bone hole and having a fluid flow pathway formed therethrough and extending between a fluid inlet port and a fluid outlet port formed in the housing, the fluid inlet and outlet ports being spaced apart from one another such that the fluid inlet port can be located adjacent a source of cerebrospinal fluid and the fluid outlet port can be located adjacent to a body cavity capable of accommodating cerebrospinal fluid drainage, and the fluid flow pathway being configured to control fluid flow between the fluid inlet and outlet ports.
2. The device of claim 1, wherein the housing includes an elongate member extending therefrom and adapted to be disposed within a bone hole.
3. The device of claim 2, wherein the elongate member is removably mated to the housing.
4. The device of claim 2, wherein the fluid inlet and outlet ports are formed in the elongate member.
5. The device of claim 4, wherein the fluid flow pathway includes a first lumen extending through the elongate member and in fluid communication with the fluid inlet port, and a second lumen extending through the elongate member and in fluid communication with the fluid outlet port.
6. The device of claim 2, further comprising a sleeve removably disposed around the elongate member and adapted to be disposed within a bone hole to anchor the elongate member within the bone hole.
7. The device of claim 6, wherein the sleeve includes a flange formed on a terminal end thereof and adapted to abut against a bone surface.
8. The device of claim 6, wherein the sleeve includes a mating element formed on an inner surface thereof and adapted to removably mate to a complementary mating element formed on an outer surface of the elongate member.
9. The device of claim 1, wherein the housing includes a central portion adapted to be disposed within a bone hole, and opposed first and second ends adapted to be positioned adjacent to opposed ends of the bone hole to anchor the central portion within the bone hole, the fluid inlet port being formed in the first end of the housing and the fluid outlet port being formed in the second end of the housing.
10. The device of claim 9, wherein the flow control component comprises a bore extending through the central portion and having a diameter effective to control fluid flow therethrough.
11. The device of claim 9, wherein the first and second ends of the housing are expandable.
12. A shunt device, comprising:
- a sleeve adapted to be anchored within a bone hole and having a lumen extending therethrough;
- a housing having a fluid flow pathway formed therethrough and a flow control component disposed within the fluid flow pathway for controlling fluid flow therethrough, and an elongate member extending from the housing and removably disposed within the lumen in the sleeve, the elongate member include inlet and outlet ports in fluid communication with the fluid flow pathway in the housing.
13. The shunt device of claim 12, wherein the elongate member is removably mated to the housing.
14. The shunt device of claim 12, wherein the inlet and outlet ports in the elongate member are spaced axially apart from one another along a length of the elongate member.
15. The shunt device of claim 12, wherein the inlet port is formed in a distal end of the elongate member and the elongate member includes a first lumen extending therethrough from the inlet port to the fluid flow pathway in the housing.
16. The shunt device of claim 15, wherein the outlet port is formed proximal to the inlet port.
17. A method of shunting fluid, comprising:
- positioning an inlet port of a shunt at a location within a patient's body in which cerebrospinal fluid can flow into the inlet port;
- anchoring a flow control component of the shunt to a vertebra, the flow control component being disposed between the inlet port and an outlet port of the shunt for controlling cerebrospinal fluid flow from the inlet port to the outlet port; and
- positioning the outlet port of the shunt at a location within the patient's body in which cerebrospinal fluid flowing from the outlet port can be drained.
18. The method of claim 17, wherein anchoring a flow control component comprises implanting a sleeve within a bone hole formed in the vertebra, and inserting an elongate member having the inlet port formed therein into the sleeve such that fluid can flow from the inlet port into a housing coupled to the elongate member and having the flow control component disposed therein.
19. The method of claim 17, wherein anchoring a flow control component comprises implanting a sleeve within a bone hole formed in the vertebra, inserting an elongate member having the inlet port formed therein into the sleeve, and coupling a housing having the flow control component disposed therein to the elongate member such that fluid flows from the inlet port in the elongate member into the housing.
20. The method of claim 17, wherein the flow control component is anchored to a location on a vertebra selected from the group consisting of a spinous process, a lamina, and a transverse process.
Type: Application
Filed: Mar 22, 2006
Publication Date: Oct 5, 2006
Applicant: Codman & Shurtleff, Inc (Raynham, MA)
Inventor: Bradley Glenn (Oneida, WI)
Application Number: 11/277,157
International Classification: A61M 5/00 (20060101);