US20160051801A1

Movatterモバイル変換

Info

Publication number: US20160051801A1
Application number: US14/743,652
Authority: US
Inventors: Abhi Vase
Original assignee: Minnetronix Inc
Current assignee: Minnetronix Inc
Priority date: 2014-08-19
Filing date: 2015-06-18
Publication date: 2016-02-25
Also published as: US20210236782A1

Abstract

The present disclosure relates to accessing, removing, exchanging and recirculating cerebrospinal fluid (CSF). Devices, systems and methods disclosed herein are used to safely and efficiently navigate the space at and around the brain and spinal cord where the CSF flows through the body, also known as the CSF space.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Application No. 62/038,998, filed on Aug. 19, 2014, entitled “Devices and Systems for Access and Navigation of Cerebrospinal Fluid Space, the contents of which are incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to systems, devices and methods for access and navigation of the cerebrospinal fluid space surrounding the brain and the spinal column.

BACKGROUND

Cerebrospinal fluid (CSF) is a generally clear, colorless fluid that is produced in the ventricles, specifically the choroid plexuses, in the brain. The choroid plexus produces approximately 500 milliliters of CSF daily in order to accommodate flushing or recycling of CSF to remove toxins and metabolites, which happens several times per day. From the choroid plexus, CSF flows slowly through a channel (canal) into the spinal column, and then into the body. CSF is found in the space between the pia mater and the arachnoid mater, known as the subarachnoid space. CSF is also found in and around the ventricular system in the brain, which is continuous with the central canal of the spinal cord. In the event of a stroke or other brain trauma, it can be desirable to remove the CSF from one location (e.g., the cervical region of the spine, or a brain ventricle), filter it, and return it to the CSF space at a second location (e.g., the lumbar region of the spine). U.S. Pat. No. 8,435,204 provides background relevant to the present disclosure, and is hereby incorporated by reference in its entirety for all purposes.

However, accurate delivery of medical instruments to the CSF space can be challenging.

Against this backdrop, the present disclosure was developed.

The information included in this Background section of the specification, including any references cited herein and any description or discussion thereof, is included for technical reference purposes only and is not to be regarded subject matter by which the scope of the invention is to be bound.

SUMMARY

Aspects of the present disclosure address the aforementioned needs by providing systems, devices and methods for the access and navigation of the cerebrospinal fluid space.

A system for access and navigation of a CSF space is disclosed. In one aspect, the system includes a curved introducer sheath having a radius of curvature configured to access and align with the cerebrospinal fluid space and an introducer coupled to a proximal end of the curved introducer sheath. In one embodiment, the introducer may have a plurality of ports, which may have a valve, such as a check valve, operably associated therewith. The system also may include a curved catheter, which may have multiple lumens and which may be configured to be received in the curved introducer.

One or more sensors or transducers may be positioned on or about the catheter. In one embodiment, at least one transducer may be a pressure sensor and at least one transducer may be a flow sensor, or one or more transducers may sense both and/or other properties. Upon delivery of the catheter through the introducer and the introducer sheath, the catheter is positioned to access and navigate the cerebrospinal fluid space.

In some aspects, the curved catheter may include a spring loaded tip, which may be in a pre-deployed position during delivery through the introducer sheath and in a deployed position after exiting the introducer sheath. In some aspects, the system may include a strain relief and/or kink resistance feature, which may be formed as a sleeve and disposed on the curved catheter (e.g., at a failure point of the curved catheter). In some aspects, the strain relief and kink resistance feature may be a coiled or a braided wire, which may be embedded in a tube comprising medical grade catheter material, such as silicone, nylon, polyurethane, aromatic polyether-based thermoplastic polyurethanes, or polyether block amide.

In some aspects, the system may include a plurality of openings defined within an outer circumferential wall of the catheter to increase fluid flow through the system. The plurality of openings may have a suitable total cross-sectional surface area, for example, at least about 0.6 mm². The plurality of openings may be positioned generally linearly along or parallel to a horizontal line defined through a central lumen of the catheter. The plurality of openings may be positioned randomly, or in a pattern, such as a staggered or symmetrical pattern, relative to a horizontal line defined through a central lumen of the catheter. In some aspects, one or more openings are defined within an outer circumferential wall one of an inlet lumen or an outlet lumen of the catheter to increase fluid flow through the system. In some aspects, at least one of the one or more openings defined within the outer circumferential wall of the inlet lumen has a total cross-sectional surface area of less than 0.01 in². In some aspects, at least one of the one or more openings defined within the outer circumferential wall of the outlet lumen has a total cross-sectional surface area of approximately 0.01 in². In certain implementations, the size of the lumen, material thickness generally, and/or other configurations of the catheter may be selected or configured to enhance the catheter's capability to unblock an opening and/or resist blockages of an opening. For example, in certain implementations, the inner wall of a lumen may have an inner diameter of approximately 0.56 mm and an outer diameter of approximately 0.71 mm, and the outer wall of the lumen may have an inner diameter of approximately 1.32 mm and an outer diameter of approximately 1.689 mm, however, other configurations are possible.

In some aspects, the system may further include a receptacle to capture and retrieve blood clots within the CSF space. In some embodiments, the receptacle may include a coiled microwire configured for delivery through the catheter to capture and retrieve a blood clot within the CSF space. In some embodiments, the receptacle comprises a plurality of intertwined microwires configured for delivery through the catheter to capture and retrieve a blood clot within the CSF space. In some embodiments, the receptacle may include a sieve coupled to a distal end of a micro-catheter and configured for delivery through the catheter to capture and retrieve a blood clot within the CSF space. Combinations of these and/or other structures also may be used.

In some aspects, the system may include a positioning device. In one embodiment, a positioning device may comprise a plurality of lumens and a plurality of balloons. Each balloon may be positioned in an individual lumen in a deflated state during delivery of the positioning device through the curved introducer sheath. The balloon may transition from a deflated state to in an inflated state and back to a deflated state during advancement of the system into the CSF space.

In some aspects, the cerebrospinal fluid space is a space where cerebrospinal fluid flows around in or through a ventricle of the brain or the cerebrospinal fluid space is a space where cerebrospinal fluid flows around in or through a spinal column.

Methods of accessing and navigating a CSF space are disclosed. One method includes introducing a curved introducer sheath having a radius of curvature, aligning the introducer sheath with the CSF space, and deploying a curved catheter having multiple lumens into the curved introducer sheath through a multi-port introducer coupled to a proximal end of the curved introducer sheath. The curved catheter may have one or more transducers positioned on or about the catheter to detect properties such as pressure, flow, and other properties. One method includes delivering the catheter through an access site in the CSF space created by the curved introducer sheath and positioning the catheter to access and navigate the CSF space. In some aspects, the CSF space is a space where cerebrospinal fluid flows around a ventricle of the brain. In some aspects, the CSF space is a space where cerebrospinal fluid flows around a spinal column.

In certain implementations, the catheter may have a length of between approximately 40 cm and approximately 120 cm and the catheter may comprise an inlet opening and an outlet opening. The inlet opening and the outlet opening may have a spacing of between approximately 10 cm and approximately 30 cm. In certain implementations, multiple lumens may comprise a first lumen defined by an inner wall and a second lumen defined between the inner wall and an outer wall. The inner wall may have an inner diameter of approximately 0.56 mm and an outer diameter of approximately 0.71 mm. The outer wall may have an inner diameter of approximately 1.32 mm and an outer diameter of approximately 1.689 mm. In certain implementations, the catheter comprises a coiled wire having a coil pitch selected to enable the catheter to be deployed and positioned without kinking or compromising flow within the catheter and to enable catheter unblocking. In certain implementations, the coil pitch may be between approximately 0.01″ and approximately 0.03″.

This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Other features, details, utilities, and advantages of the present invention will be apparent from the following more particular written description of various embodiments of the invention as further illustrated in the accompanying drawings and defined in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure, both as to its organization and manner of operation, may be understood by reference to the following description, taken in connection with the accompanying drawings, in which:

FIG. 1 depicts aspects of a system for access and navigation of the cerebrospinal fluid space in accordance with the present disclosure;

FIGS. 2 through 4 illustrate various embodiments of an introducer of the system ofFIG. 1;

FIGS. 5 and 6 illustrate one embodiment of a catheter of the system ofFIG. 1;

FIGS. 7 through 9 illustrate some embodiments of a catheter of the system ofFIG. 1 having spring-loaded tips;

FIG. 10 illustrates an embodiment of a catheter of the system ofFIG. 1;

FIG. 11 illustrates a first, distal portion of the catheter ofFIG. 10;

FIG. 12 illustrates a second, medial portion of the catheter ofFIG. 10;

FIG. 13 illustrates an embodiment of a catheter of the system ofFIG. 1;

FIG. 14 illustrates a first, distal portion of the catheter ofFIG. 13;

FIG. 15 illustrates a second, medial portion of the catheter ofFIG. 13;

FIG. 16 illustrates an embodiment of a catheter of the system ofFIG. 1;

FIG. 17 illustrates a first, distal portion of the catheter ofFIG. 16;

FIG. 18 illustrates a second, medial portion of catheter ofFIG. 16;

FIG. 19 illustrates an embodiment of a catheter of the system ofFIG. 1;

FIG. 20 illustrates a first, distal portion of the catheter ofFIG. 19;

FIG. 21 illustrates a second, medial portion of the catheter ofFIG. 19;

FIG. 22 illustrates an embodiment of a catheter of the system ofFIG. 1;

FIG. 23 illustrates a first, distal portion of the catheter ofFIG. 22;

FIG. 24 illustrates a second, medial portion of the catheter ofFIG. 22;

FIG. 25 illustrates an embodiment of a catheter of the system ofFIG. 1;

FIG. 26 illustrates a first, distal portion of the catheter ofFIG. 25;

FIG. 27 illustrates a second, medial portion of the catheter ofFIG. 25;

FIGS. 28 through 31 illustrate several embodiments of a blood clot removal device of the system ofFIG. 1 having a coiled microwire;

FIG. 32 illustrates an embodiment of a blood clot removal device of the system ofFIG. 1 having a plurality of intertwined micro-wires;

FIG. 33 illustrates an embodiment of a blood clot removal device of the system ofFIG. 1 having a sieve mechanism;

FIG. 34 illustrates an embodiment of a blood clot removal device of the system ofFIG. 1 having a plurality of microwires;

FIGS. 35 through 38 depict an embodiment of a positioning device with one or more inflatable balloons for use with the system ofFIG. 1;

FIGS. 39 and 40 depict an embodiment of a dual lumen catheter having proximal and distal ends with varying diameters for use with the system ofFIG. 1;

FIGS. 41 and 42 depict an embodiment of a dual lumen catheter having a proximal end with different dimensions than a distal end of the catheter for use with the system ofFIG. 1;

FIGS. 43 and 44 depict an embodiment of a catheter configured for use as a peripherally inserted dual lumen central catheter having an inlet lumen and an outlet lumen and for use with the system ofFIG. 1;

FIGS. 45 through 47 depict another embodiment of a dual lumen catheter for use with the system ofFIG. 1;

FIGS. 48 through 50 depict an embodiment of a multi-lumen catheter for use with the system ofFIG. 1 having three inlet lumens and an outlet lumen;

FIGS. 51 through 53 depict an embodiment of a multi-lumen catheter for use with the system ofFIG. 1 having two inlet lumens and an outlet lumen;

FIGS. 54 and 55 depict another embodiment of a dual lumen catheter for use with the system ofFIG. 1;

FIGS. 56 and 57 illustrate openings of an inlet lumen and an outlet lumen, respectively;

FIGS. 58 and 59 depict a comparison between various embodiments of the lumens disclosed herein and known lumens;

FIG. 60 illustrates a Y-connector portion, a proximal subassembly, and a distal subassembly of a catheter according to certain implementations;

FIG. 61 illustrates a sectional view taken from the region of the catheter ofFIG. 60 marked with cutting plane line A-A;

FIG. 62 illustrates a sectional view taken from the region of the catheter ofFIG. 60 marked with cutting plane line B-B;

FIG. 63 illustrates an enlarged, detail view of a portion of the Y-connector of the catheter ofFIG. 60;

FIG. 64 illustrates the location of position markers on a catheter according to certain implementations;

FIG. 65 illustrates a sectional view taken from the region of the catheter ofFIG. 64 marked with the cutting plane line J-J;

FIG. 66 illustrates a portion of a catheter near the joining of a proximal subassembly and a distal subassembly according to certain implementations;

FIG. 67 illustrates a portion of a proximal subassembly according to certain implementations;

FIG. 68 illustrates a detail view of the proximal subassembly ofFIG. 67;

FIG. 69 illustrates a sectional view taken from the region of the proximal subassembly ofFIG. 67 marked with the cutting plane line A-A;

FIG. 70 illustrates a detail view of a portion of the proximal subassembly ofFIG. 68 taken from the view of line D-D;

FIG. 71 illustrates a sectional view taken from the region of the proximal subassembly ofFIG. 67 marked with the cutting plane E-E;

FIG. 72 illustrates a portion of a distal subassembly according to certain implementations;

FIG. 73 illustrates a detailed portion of the distal subassembly ofFIG. 72;

FIG. 74 illustrates a detailed portion of the distal subassembly ofFIG. 72; and

FIG. 75 illustrates a sectional view taken from the region of the distal subassembly ofFIG. 72 marked with the cutting plane A-A.

DETAILED DESCRIPTION

The present disclosure relates to removal, exchange and recirculation of cerebrospinal fluid (CSF). Devices, systems and methods disclosed herein are used to safely and efficiently navigate the space at and around the brain and spinal cord where the CSF flows through the body, also known as the CSF space. Specialized devices and systems are useful and sometimes necessary to navigate the CSF space due to the difficult points of entry and exit and the potentially life threatening consequences if a mistake is made. Increased safety and efficacy reduce time spent in the surgical suite and potential complications.

Neuropheresis is the removal of blood from CSF. This and other therapeutic techniques can be used to treat a number of neurological diseases or conditions, such as Alzheimer's Disease, Parkinson's Disease, Huntington's Disease, Amyotrophic Lateral Sclerosis (ALS), Encephalitis from various causes, Meningitis from various causes, Guillain Barre Syndrome (GBS), Multiple Sclerosis (MS), Spinal Cord Injury, Traumatic Brain Injury, cerebral vasospasm, stroke and other diseases or conditions as described in previously mentioned U.S. Pat. No. 8,435,204.

The purification, conditioning, and/or compound removal schema can be tailored to a specific disease or group of diseases as suitable, including based on a number of features, such as size, affinity, biochemical properties, temperature, and other features. Purification schema may be based on diffusion, size-exclusion, ex-vivo immunotherapy using immobilized antibodies or antibody fragments, hydrophobic/hydrophilic, anionic/cationic, high/low binding affinity, chelators, anti-bacterial, anti-viral, anti-DNA/RNA/amino acid, enzymatic, and magnetic and/or nanoparticle-based systems. The system can be adjustable to a broad range of biologic parameters and flows.

With regard to a neuropheresis system in particular, the disclosed system can be used to safely and quickly access the CSF space with minimal disturbance to the CSF flow. The systems and devices disclosed herein provide a safe a rapid flow circuit and provide filtration by reducing the number of red blood cells in the circuit and providing for blood clot identification and removal.

A neuropheresis system should provide for the exchange, removal, and/or recirculation of CSF, safely and efficiently. The systems and devices disclosed herein may be used in a neuropheresis system. Previously described single lumen catheter systems produce only a local eddy, with minimal mixing and therefore recirculation of previously processed CSF. Such single lumen systems do not generate enough mixing to adequately draw or circulate fluid from the CSF space. The rate of mixing, the amount of new CSF turned over per minute, and the access provided to turning over the cranial and spinal CSF volume multiple times using the present invention results in a much more rapid, efficient, and feasible CSF processing system that may provide access to up to the entire CSF system. The system may provide for an adjustable distance between the inflow and outflow areas, to provide enhanced ability to mix and circulate CSF.

The systems and devices disclosed herein can be used to access the CSF space to remove the CSF from one location (e.g., the cervical region of the spine, or a brain ventricle), filter or otherwise treat it, and return it to the CSF space, including at a second location (e.g., the lumbar region of the spine), safely and efficiently. In various aspects, the systems and devices disclosed herein maintain the endogenous intracranial or intraspinal pressure within a physiological range, for example, from about 5 to about 20 mm Hg or from about 0 to about 10 mm Hg or from about −5 to about 10 mm Hg or from about −5 to about 25 mm Hg. The present system thus reduces spinal headache, for example, due to hydrocephalus (abnormal accumulation of CSF in the ventricles of the brain). In some aspects, the system may include sensors within the catheter or within the flow circuit to detect clogs or blockages in the system, thereby providing closed loop pressure control. In various aspects, the systems and devices disclosed herein also help the system to perform efficiently by reducing or eliminating recirculating flow loops. The systems and devices maintain spacing between the inlet and outlet, for example, between about 10 cm to about 40 cm. In certain implementations, the spacing is between about 10 cm and about 30 cm. The inlets and outlets are located in places in the CSF space so that turning on the pump or otherwise creating positive or negative pressure in the system will not cause or encourage tissue being drawn into the catheter. In some aspects, the inlets and outlets are placed near the lumbar cervical cisterns to prevent tissue from being drawn into the catheter. In some aspects, there may also be multiple holes along the inlet and outlet for redundancy in case there is tissue blocking some number of holes. In certain implementations, a particular coil pitch of a coiled wire within the catheter may be selected in order to facilitate catheter unblocking and/or the ability of the catheter to resist blockage. In certain aspects, the inlet-outlet spacing may be selected to be maximized while staying below the level of a cervical region of a patient. In certain aspects, the inlet-outlet spacing may be selected based on vertebral spacing. For example, the spacing may be selected so that the inlet-outlet spacing is between the lengths of approximately 5 vertebrae and approximately 12 vertebrae. In certain implementations, a spacing of approximately 10 vertebrae may be selected; however, other configurations (such as those described elsewhere in the specification) may be utilized. When designing such spacing, it may be assumed that a vertebra is approximately 2-3 cm in length, however, other measurements and designs may be used. In certain implementations, a particular size, shape, and/or other configuration of a lumen may be selected to facilitate catheter unblocking and/or the ability of the catheter to resist blockage. For example, a proximal outer diameter of a lumen of between approximately 0.060 inches and approximately 0.070 inches and a proximal inner diameter of between approximately 0.025 inches and 0.060 inches may be selected; however, other configurations (such as those described elsewhere in the specification) may be utilized.

The disclosed systems and devices are used to access the CSF space and may be used at any access point in the cervical (C1-C7), thoracic (T1-T12), or lumbar region (L1-L5) of the vertebral column. An access site in the cervical region may be used to access the ventricular system in the brain. In one embodiment, the system and device are used to access the lumbar region. In some embodiments, the inlets and outlets are located in places in the spine such that the drainage process will not cause tissue to be drawn into the catheter. For example, when a patient is lying on a table, entry may be made at a suitable angle, such as, for example, about 90 degrees, to access the spine. A traditional catheter must be pushed through a 90 degree bend at the L4-L6 region. The catheters and related delivery devices disclosed herein may be curved such that they can access and navigate this angled bend more easily and efficiently.

For a discussion of the systems and devices that provide access to and help to navigate the CSF space for CSF filtration, removal and exchange, reference is now made toFIGS. 1-59.

FIG. 1 illustrates one embodiment of the disclosed system and devices for CSF access and navigation. The CSF access andnavigation system5 includes acurved introducer sheath20 specifically designed to access theCSF space15. Thesystem5 is shown being introduced into thelumbar region10 of a patient. Theintroducer sheath20 may be a single lumen, dual-lumen, or multi-lumen device. In one embodiment, theproximal end21 of theintroducer sheath20 may include amulti-port introducer25, and each port may have a valve, such as a hemostasis valve or a one way valve, to prevent CSF or other fluid from passing through the port. Once theintroducer20 is inserted into the patient, acatheter30 may be inserted into theintroducer20. Thecatheter30 may be curved, to complement theintroducer20. In some embodiments, disposed on or within thecatheter30 aresensors40, such as flow and/orpressure sensors40, and/or sensors for other properties, such as temperature. In some aspects, thesystem5 may also include a separate catheter with a basket or other receptacle at its distal end to capture and remove debris, such as a blood clot. In some embodiments, thesystem5 also includes a multi-lumen device having inflatable balloons to advance thecatheter30 into the spinal canal and theCSF space15. In some embodiments, balloons50 may be co-located with or disposed about thecatheter30 and may be anchoringballoons50aorannular balloons50b. Theballoons50 are configured to stabilize the catheter during use. In some embodiments, the balloons may be radiopaque to provide increased visualization of thecatheter30 within the CSF space.

Curved Introducer Sheath

FIGS. 2-4 depict various aspects of thecurved introducer sheath20 with an optionalmulti-port introducer25. As can be understood fromFIG. 2, thecurved introducer sheath20 has dimensions and orientation which align with the CSF space, which can be difficult to navigate. In one embodiment, thesheath20 is made of a polyurethane jacket over a metal or metal alloy core. The metal core may be a flexible nitinol alloy, to maintain the slight bend during introduction and navigation, and retain that slight bend despite repeated use. In certain embodiments, thecurved introducer sheath20 may be configured to have a bend radius of between approximately 2 mm and approximately 7 mm. The jacket may be of a braided construction embedded within silicone, nylon, or polyurethane. The use of a nitinol core enables the distal end of thesheath20 to be more “spring-like” and move back to its original shape when it is delivered through a hollow tube (e.g., a Tuohy needle). In one embodiment, thesheath20 has a generally hydrophilicdistal section20ato facilitate smooth placement of the catheter into the lumbar region (e.g., L3/L4). The sheath helps prevent tracking of blood and tissue into the spinal canal, to reduce the incidence of blockages when the therapy begins. Thesheath20 may further enable a 5F or 6F catheter having a length of approximately 7 cm to approximately 11 cm to be placed above or below the spinal cord. The distal section includes ashaft region20band generallycurved tip20c, which may crescent shaped or similar to the shape of a hockey stick. Thedistal section20ais between approximately 10 cm to approximately 15 cm in length and thetip20cis approximately 2-4 cm in length. The angle between theshaft region20band thetip20cis approximately 120 degrees. In certain embodiments a catheter may comprise regions or portions having different thicknesses, diameters, materials, coils, coil pitches, and other features and designs to facilitate a particular bend radius and/or optimal pushability without compromising safety.

In use, theintroducer sheath20 may be inserted through or over a needle (not shown), such as a Tuohy needle, that has punctured theCSF space15, for example, the cervical or lumbar area of the spine. The needle may be removed, leaving theintroducer sheath20 behind. Theintroducer sheath20 may be curved to guide instruments from outside the body into the CSF space via amulti-port introducer25, for example.

Multi-Port Introducer

An introducer may be used at theproximal end21 of theintroducer sheath20. Any suitable introducer may be used, as desired, including a single-port introducer. As shown inFIGS. 2-4, in one embodiment, amulti-port introducer25 may be attached or coupled to theproximal end21 of theintroducer sheath20, for example by aconnector23. Theconnector23 may be a Luer-Lock fitting, such as the Luer-Lok manufactured by Becton, Dickinson and Company. Themulti-port introducer25 includes a plurality of ports oropenings26 and aknob24 or other structure to help with the steerability of the introducer. The knob may be associated with a valve, and/or it may help indicate the orientation of the catheter based on where the location of the end of the curved sheath/catheter. That is, if the knob is on the same side of the catheter as the curved tip, then when the catheter is in situ, the user will know the orientation of the curved tip as indicated by the knob. Themulti-port introducer25 may be made of any suitable material, such as an injection-molded plastic. Theconnector23 may be made of nylon, polypropylene, polycarbonate or PVDF, or other appropriate material. In one embodiment, the introducer/sheath/peelaway sheath is configured for a 6F catheter and has a shaft length of about 7 cm to about 11 cm and the guidewire is about 120 cm to about 180 cm in length which equates to the length of the catheter outside the body, which is from approximately 80 cm to approximately 130 cm, plus approximately 40 cm to approximately 60 cm, which is approximately the length of the catheter in the spine.

Theintroducer25 may include any suitable number of ports. In one embodiment, theintroducer25 includes fourports26. In other embodiments, theintroducer25 includes one port, two ports, three ports, five ports, six ports or more. Eachport26 includes avalve27 or other structure to prevent backflow or fluid from leaking from the CSF space and out through theport26. In one embodiment, thevalve27 is a check valve, a one-way valve, or non-return valve. Thevalve27 may be adapted such that a catheter or other device may be introduced through thevalve27 without allowing fluid within the lumen ofintroducer sheath20 to escape, and, conversely, without allowing foreign substances to enter the lumen ofintroducer sheath20. In certain implementations, theports26 andvalves27 may be used to sample fluid at multiple time points and/or for checking flow/pressure.

Themulti-port introducer25 may be a manifold or entry point for catheters, endoscopes, guidewires, flush tubes, and/or other medical instruments, and thesheath20 may include a lumen for passing any of these. Each port may have the same or similar diameter or may have different diameters. In one embodiment, as shown inFIG. 3, a fourport introducer25 includes two

small diameter ports

26a,26band two

larger diameter ports

26c,26d. The two

smaller diameter ports

26a,26bmay have a diameter of approximately 0.3 mm to approximately 1 mm and are configured to receive amedical instrument28, such as a pressure transducer and/or flow transducer or sensors or other smaller diameter instrument. The two

larger diameter ports

26c,26dmay have a diameter of approximately 1 mm to approximately 3 mm and are configured to receive amedical instrument28, such as a flow catheter or other larger diameter instrument. In certain implementations, theintroducer25 may have a radiused or otherwise tapered design configured to maintain a good seal with the catheter to prevent or substantially resist accumulation of debris as well as fluid leakage back from the catheter.

In use, the surgeon can attach themulti-port introducer device25 to theproximal end21 of theintroducer sheath20 or thedevice25 may already be attached prior to use. The surgeon can then use thevarious ports26 to insert and/or remove differentmedical instruments28, such as guidewires, cauterizers, micro-manipulators, sensors, etc. through theintroducer sheath20 and into a catheter in the CSF space for a procedure. Advantageously, theinstruments28 are aligned with the CSF space in the spinal column after introduction through theintroducer sheath20.

Catheter

As indicated inFIGS. 5-27, and with reference toFIG. 1, thesystem5 may further include acurved catheter30. In some embodiments, thecatheter30 may include a shielded coating for MRI-safety and to provide little to no reduction in image quality with specific scans such as gradient echo scans or fast spin scans. In some embodiments, thecatheter30 is a 5F catheter. In some embodiments, thecatheter30 is a 6F catheter with an approximately 7-10 cm introducer. In some embodiments, as shown inFIGS. 5 and 6, thetip31 ofcatheter30 may be spring-loaded, such that thecatheter30 maintains a generally linear form during delivery through theintroducer20 but transitions into a curved shape as it exits theintroducer sheath20 or needle. In one embodiment, thetip31 is a curved atraumatic spring-loaded tip. Thespring32 may be made of a shape memory material, such as nitinol, or metal, such as stainless steel, or a metal alloy. In other embodiments, coil, braid, mesh, or other materials can be used in addition to or in lieu of a spring. The spring loadedtip31 has a curved shape with a curve or bend of less than or equal to about 90 degrees. As explained above with respect to the curved introducer sheath, the curve or bend in the catheter tip facilitates a smooth transition from the outside of the body in the L5 region through to the spinal canal. In addition, it helps to avoid nerve roots in this region and help align the distal tip for its movement up to the cervical region. The curve or angle provides access to the CSF space on a patient that is likely lying perpendicularly, but the catheter and wire make a bend to traverse the canal smoothly and with reduced or minimal kinking, pinching, and/or strain near the point of entry. Sharp bends of 90 degrees or less can reduce flow of CSF through the catheter and facilitate clotting via the formation of stagnant flow and local eddy currents, which can block holes and result in therapy failure. In certain embodiments, the bend radius may be between approximately 0 mm and approximately 10 mm. In certain implementations, this bend radius may enable optimal CSF flow through a luminal device in the spinal canal. In some embodiments, the bend radius may be between approximately 3 mm and approximately 7 mm. In certain embodiments, the catheter may comprise a coiled wire having a coil pitch selected to provide particular rigidity for navigation and for unblocking the catheter For example, in certain implementations, the coil pitch may be between approximately 0.01 inches and approximately 0.03 inches. In some embodiments, thecatheter30 is a lumbar catheter and is configured for delivery in a lumbar region of the spinal column. In some embodiments, thecatheter30 is a cervical catheter and is configured for delivery in a cervical region of the spinal column. While certain embodiments of the introducer, introducer sheath, catheter and other components of the present invention may be described as having a curve, bend radius, or a radius of curvature, it is to be understood that some or all of the components of the present invention may be provided straight, i.e., with no curve.

In use, once theintroducer sheath20 is in place in the patient, a catheter30 (or other instruments) can be introduced through the introducer into the CSF space.

Advantageously, thecatheter30 is aligned with the CSF space in the spinal column after introduction through theintroducer sheath20. In some embodiments, the catheter is navigated up to the cervical region in the C-2 area, or higher into the ventricles, to facilitate the drainage of fluids.

As illustrated inFIGS. 7-27, thecatheter30 may include structures that assist in the access to and/or navigation of the CSF space, and that facilitate the efficacy of the neuropheresis. Some of these structures include, but are not limited to, temperature, pressure, flow, and/or other sensors or transducers40 (see, e.g.,FIG. 1); structures to provide strain relief and/or kink resistance to the catheter (see, e.g.,FIGS. 7-9, among others); visualization features (see, e.g.,FIGS. 10-27); structures to increase flow profile (see, e.g.,FIGS. 10-27); structures to unblock and/or catch blood clots, to reduce filter clogging (see, e.g.,FIGS. 28-33); structures to help position or advance the catheter within the CSF space (see, e.g.,FIGS. 1 and 11); and structures to allow multiple instruments to be introduced into the CSF space simultaneously (see, e.g.,FIGS. 39 through 52).

Sensors

As can be understood fromFIG. 1, in some embodiments,transducers40, such as sensors ormicrosensors40, are positioned on or about thecatheter30 or other instrument or may be embedded within the catheter wall. Thetransducers40 may include pressure sensors, flow sensors, temperature sensors and/or sensors designed to measure other parameters such as viscosity, turbidity, or the like associated with normal, disease, and/or injury states of the CSF space. Thetransducers40 may be positioned along the length L of the catheter or at or near adistal end33 of thecatheter30. Thetransducers40 may be positioned at locations that correspond to specific lumbar or cervical regions of the spine and measure flow and pressure at those locations. The pressure and flow sensors may also be used for kink or clog detection, as described below.

Strain Relief and Kink Resistance

As indicated inFIGS. 7-9 and with reference toFIGS. 10-27, thecatheter30 may include a strain relief and kinkresistance feature60. Thefeature60 may be a sleeve configured to be positioned over or about thecatheter30 at a desired location and may be “locked” in position (e.g., passive fixation) for a period of time, such as between about 30 minutes and about 120 minutes. For example, such afeature60 may be provided at afracture point61 of the body of thecatheter30 for strain relief and to allow flex or deformation of the catheter (seeFIG. 9). As shown inFIG. 7, in one embodiment, thefeature60 is a coiledwire62, which may be embedded in aflexible tube63, such as a silicone or polyether block amide (e.g., as sold under the trade name PEBAX)tube63.

In certain implementations, the coiledwire62 may comprise an approximately 0.003″ round wire. In certain implementations, the coiledwire62 may be configured with a coil pitch of between approximately 0.01″ and approximately 0.03″, however other configurations are also possible. This arrangement may enable the catheter to make a bend into a spinal canal and retain its position without kinking or compromising flow and flow under suction. In some implementations, the pitch may change over the length of thecatheter30. For example, a distal section may have a coil pitch of between approximately 0.06″ and approximately 0.07″, while a proximal portion may have a coil pitch of between approximately 0.01″ and approximately 0.03″. In some implementations, the coil pitch may be between approximately 0.027″ and approximately 0.037″ in the proximal section. The coil pitch may be selected to enable the size of inlet or other holes in the catheter to fit within the coil spacing. The coil pitch may also be selected to enable a kink-resistant design while maintaining pushability.

In another embodiment, as shown inFIG. 8, thefeature60 may be abraided wire64 embedded in atube63. In various embodiments, thefeature60 is between approximately 3 inches and approximately 10 inches in length. In some embodiments, thefeature60 is approximately 3 inches, approximately 4 inches, approximately 5 inches, approximately 6 inches, approximately 7 inches, approximately 8 inches, approximately 9 inches, approximately 10 inches in length, or any other desired dimension.

As can be seen inFIG. 10 and others, aposition marker100, such as a green polyether block amide (e.g., PEBAX)position marker100, may be integral with the catheter, or it may be positioned about or around the catheter. Theposition marker100 is provided to indicate a transition point of the catheter at a point where it is entering/exiting the body. Such an indicator may be useful if imaging technology (e.g., MRI) is not used and the indicator can provide a guide. Theposition marker100 also provides additional strength and kink resistance.

Visualization Features

In some embodiments, as shown inFIGS. 10-27, thecatheter30 may include avisualization feature70 for diagnostic imaging purposes. Thevisualization feature70 may be amarker band70 that will help to confirm the location of the inlet and outlet at, for example, the cisterns in the spine, rather than placing the catheter near nerve tissue, soft pia mater, or other tissue that can be drawn into the catheter, thereby reducing flow.

Increased Flow Profile

CSF flow through the spinal column is considered a generally low flow system, as compared to a higher flow system such as the cardiac system. As can be understood fromFIGS. 10-27, to increase the CSF or other fluid flow profile through thesystem5, thecatheter30 optionally may include a plurality of openings80 (which may or may not have a defined pattern) along certain portions of thecatheter30. Theopenings80 may be elongated openings defined within the outercircumferential wall30aof thecatheter30 and may be of oval, elliptical, other, or undefined shape. In some embodiments, the plurality ofopenings80 has a total cross sectional surface area of approximately 0.6 mm²or greater, or approximately 1.5 mm². In general, the ratio of the cross sectional area of theopenings80 to the cross sectional area of an internal lumen of thecatheter30 is from 1:1 to 3:1. In one embodiment, the plurality ofopenings80 has a total cross sectional surface area of approximately 0.8 mm². The openings80 (which may be vents, slots, slits, or other) in thecatheter30 provide an increased flow profile for thesystem5.

As shown inFIGS. 11 and 12, and with reference toFIG. 10, in one embodiment, afirst portion85 ofcatheter30 may optionally include a plurality ofopenings80 positioned generally linearly along or generally parallel to or along a horizontal line through a lumen of thecatheter30. Thedistal end86 of thefirst portion85 may optional includes a round or rounded tip, or a soft distal portion, to prevent puncture or lessen damage to any nearby tissue or other anatomical feature during delivery of the device. The length L_Fof thefirst portion85 is approximately 2 cm. Asecond portion90 ofcatheter30 includes a plurality ofopenings80, which may be positioned in a random, staggered, symmetrical, or other pattern (or non-pattern) relative to a horizontal line defined through a lumen of thecatheter30. Thesecond portion90 also optionally may include a spring orcoil95, which may be provided for reinforcement of the inner and outer lumens. The function of thespring95 is to lessen the likelihood of collapse of the section, from suction or from the weight of tissue on the catheter or otherwise. The coil orspring95 may be made of platinum, stainless steel, or other suitable materials depending on whether imaging is desired. Any suitable number of springs or coils may be used. The length L_Sof thesecond portion90 is approximately 3 cm. The distance D₁between adistal end86 of thefirst portion85 and adistal end91 of thesecond portion90 is approximately 30 cm. The distance D₂between adistal end86 of thefirst portion85 and a proximal end92 of thesecond portion90 is approximately 33 cm. In some embodiments, the distance D₂between adistal end86 of thefirst portion85 and a proximal end92 of thesecond portion90 is between approximately 33 cm and approximately 38 cm. The total length L₁of thecatheter30 is approximately 68 cm. The distance D₃between the proximal end92 of thesecond portion90 and adistal end93 of theposition marker100 is approximately 6 cm.

As shown inFIGS. 14 and 15, and with reference toFIG. 13, in one embodiment, afirst portion85 ofcatheter30 may optionally include a plurality ofopenings80 positioned generally linearly along or generally parallel to or along a horizontal line through a lumen of thecatheter30. Thedistal end86 of thefirst portion85 may include a round or rounded tip or a soft distal end portion to prevent puncture or lessen damage to any nearby tissue or other anatomical feature during delivery of the device. The length L_Fof thefirst portion85 is approximately 2 cm. Asecond portion90 ofcatheter30 includes a plurality ofopenings80, which may be positioned in a random, staggered, symmetrical, or other pattern relative to the horizontal line through a lumen of thecatheter30. The length L_sof thesecond portion90 is approximately 3 cm. The distance D₁between adistal end86 of thefirst portion85 and adistal end91 of thesecond portion90 is approximately 20 cm. The distance D₂between adistal end86 of thefirst portion85 and a proximal end92 of thesecond portion90 is approximately 23 cm. The total length L₁of thecatheter30 is approximately 58 cm. The distance D₃between the proximal end92 of thesecond portion90 and adistal end93 of theposition marker100 is approximately 6 cm.

As shown inFIGS. 17 and 18, and with reference toFIG. 16, in one embodiment, afirst portion85 ofcatheter30 may optionally include a plurality ofopenings80 positioned generally linearly along or generally parallel to a horizontal line through a lumen of thecatheter30. Thedistal end86 of thefirst portion85 may include a round or rounded tip or a soft distal end portion to prevent puncture or lessen damage to any nearby tissue or other anatomical feature during delivery of the device. Thefirst portion85 also may include springs or coils95a,95bseparated by amarker band70. The springs or coils95 resist reinforcement of the inner and outer lumens. The separation of the

springs

95a,95bresists collapse of the section from suction or from the weight of tissue on the catheter. The coils or springs95 may be made of platinum or stainless steel depending on whether imaging is desired. Any suitable number of springs or coils may be used, with or without one or more marker bands. The length L_F1of thefirst portion85 between thedistal end86 and themarker band70ais approximately 2 cm. The length L_F2of thefirst portion85 between themarker band70aandmarker band70bis approximately 2 cm. Asecond portion90 ofcatheter30 may include a plurality ofopenings80 positioned in a random, staggered, symmetrical, or other pattern relative to a horizontal line through a lumen of thecatheter30. Thesecond portion90 also may include aspring95c. The separation of the

springs

95a,95band95cresists collapse of the section from suction or from the weight of tissue on the catheter. The length L_Sof thesecond portion90 is approximately 3 cm. The distance D₁between adistal end86 of thefirst portion85 and adistal end91 of thesecond portion90 is approximately 30 cm. The distance D₂between adistal end86 of thefirst portion85 and a proximal end92 of thesecond portion90 is approximately 33 cm. In some embodiments, the distance D₂between adistal end86 of thefirst portion85 and a proximal end92 of thesecond portion90 is between approximately 33 cm and approximately 38 cm. The total length L₁of thecatheter30 is approximately 68 cm. The distance D₃between the proximal end92 of thesecond portion90 and adistal end93 of theposition marker100 is approximately 6 cm.

As shown inFIGS. 20 and 21, and with reference toFIG. 19, in one embodiment, afirst portion85 ofcatheter30 includes a plurality ofopenings80 positioned generally linearly along or generally parallel to a horizontal line through a central lumen of thecatheter30. Thedistal end86 of thefirst portion85 may include a round or rounded tip or soft distal end portion to prevent puncture or lessen damage to any nearby tissue or other anatomical feature during delivery of the device. Thefirst portion85 also may include

springs

95a,95bseparated by amarker band70. The springs or coils95 resist reinforcement of the inner and outer lumens. The coils or springs95 may be made of platinum, stainless steel, or other suitable materials depending on whether imaging is desired. The separation of the

springs

95a,95bresists collapse of the section from suction or from the weight of tissue on the catheter. The coils or springs95 may be made of platinum, stainless steel, or other suitable materials depending on whether imaging is desired. Any suitable number of springs or coils may be used. The length L_F1of thefirst portion85 between thedistal end86 and themarker band70ais approximately 2 cm. The length L_F2of thefirst portion85 between themarker band70aandmarker band70bis approximately 2 cm. Asecond portion90 ofcatheter30 may include a plurality ofopenings80 positioned in a random, staggered, symmetrical or other pattern relative to a horizontal line through a lumen of thecatheter30. Thesecond portion90 also includes aspring95c. The separation of the

springs

95a,95band95cresists collapse of the section from suction or from the weight of tissue on the catheter. The length L_Sof thesecond portion90 is approximately 3 cm. The distance D₁between adistal end86 of thefirst portion85 and adistal end91 of thesecond portion90 is approximately 20 cm. The distance D₂between adistal end86 of thefirst portion85 and a proximal end92 of thesecond portion90 is approximately 23 cm. The total length L₁of thecatheter30 is approximately 58 cm. The distance D₃between the proximal end92 of thesecond portion90 and adistal end93 of theposition marker100 is approximately 6 cm.

As shown inFIGS. 23 and 24, and with reference toFIG. 22, in one embodiment, afirst portion85 ofcatheter30 includes a plurality ofopenings80 positioned in a random, staggered, symmetrical or other pattern relative to a horizontal line through a lumen of thecatheter30. Thedistal end86 of thefirst portion85 may include a round or rounded tip or a soft distal end portion to prevent puncture or lessen damage to any nearby tissue or other anatomical feature during delivery of the device. Thefirst portion85 may also include aspring95d. The spring orcoil95 resists reinforcement of the inner and outer lumens. The coil orspring95 may be made of platinum, stainless steel, or other suitable materials depending on whether imaging is desired. Any suitable number of springs or coils may be use. The length L_Fof thefirst portion85 is approximately 2.1 cm. Asecond portion90 ofcatheter30 may include a plurality ofopenings80 positioned in a random, staggered, symmetrical or other pattern relative to a horizontal line defined through a lumen of thecatheter30. Thesecond portion90 also includes aspring95e. The separation of the

springs

95dand95eresists collapse of the section from suction or from the weight of tissue on the catheter. The length L_Sof thesecond portion90 is approximately 3 cm. The distance D₁between adistal end86 of thefirst portion85 and adistal end91 of thesecond portion90 is approximately 30 cm. The distance D₂between adistal end86 of thefirst portion85 and a proximal end92 of thesecond portion90 is approximately 33 cm. In some embodiments, the distance D₂between adistal end86 of thefirst portion85 and a proximal end92 of thesecond portion90 is between approximately 33 cm and approximately 38 cm. The total length L₁of thecatheter30 is approximately 68 cm. The distance D₃between the proximal end92 of thesecond portion90 and adistal end93 of theposition marker100 is approximately 6 cm.

As shown inFIGS. 26 and 27, and with reference toFIG. 25, in one embodiment, afirst portion85 ofcatheter30 includes a plurality ofopenings80 positioned in a random, staggered, symmetrical or other pattern relative to a horizontal line through a lumen of thecatheter30. Thedistal end86 of thefirst portion85 includes a round or rounded tip or soft distal end portion to prevent puncture or lessen damage to any nearby tissue or other anatomical feature during delivery of the device. Thefirst portion85 may include aspring95. The spring orcoil95 resists reinforcement of the inner and outer lumens. The coil orspring95 may be made of platinum or stainless steel depending on whether imaging is desired. Any suitable number of springs or coils may be use. The length L_Fof thefirst portion85 is approximately 2.1 cm. Asecond portion90 ofcatheter30 may include a plurality ofopenings80 positioned in a random, staggered, symmetrical or other pattern relative to the horizontal line through a lumen of thecatheter30. The length L_Sof thesecond portion90 is approximately 3 cm. The distance D₁between adistal end86 of thefirst portion85 and adistal end91 of thesecond portion90 is approximately 20 cm. The distance D₂between adistal end86 of thefirst portion85 and a proximal end92 of thesecond portion90 is approximately 23 cm. The total length L₁of thecatheter30 is approximately 58 cm. The distance D₃between the proximal end92 of thesecond portion90 and adistal end93 of theposition marker100 is approximately 6 cm.

Blood Clot Removal

In some embodiments, thesystem5 orcatheter30 may be used with other devices to help increase the efficiency and safety of the neuropheresis system. For example, blood clots can reduce or stop fluid flow in the vasculature and can cause similar problems in the CSF space. As such, their removal is desirable and can be accomplished with aspects of the systems and devices disclosed herein. In some embodiments, a chemical agent, such as saline, tissue plasminogen activator (tPA), or urokinase, may be introduced into the CSF space through thecatheter30 to unblock clots. To retrieve those clots, thesystem5 may further include a basket, coiled wire, orother receptacle105 to hold or remove pieces of the clot to reduce or prevent clogging of a filter.

As shown inFIGS. 28 through 31, thereceptacle105 may be acoiled microwire110 that may be inserted into thecatheter30 and advanced to the blood clot C. Aballoon108 may be positioned over thecatheter30 to either push tissue away from the openings in the catheter and enable flow to occur more easily, or to actually perform the function of isolation while suction (via pump) and/or mechanical manipulation with the micro-wires is applied. Thecoiled microwire110 engages blood clot C by intertwining with pieces of clot C (seeFIGS. 29 and 30). Themicrowire110 with clot C intertwined may be withdrawn through thecatheter30, thereby removing the clot C from the CSF space (FIG. 31).

As indicated inFIG. 32, in another embodiment, thereceptacle105 may include a plurality ofintertwined microwires115 that may be inserted into thecatheter30 and advanced to the blood clot C. Themultiple microwires115 engage blood clot C by intertwining with pieces of clot C. Themicrowires115 with clot C intertwined therein may be withdrawn through thecatheter30, thereby removing the clot C from the CSF space.

As illustrated inFIG. 33, in another embodiment, thereceptacle105 may be asieve mechanism120 that may be attached to amicrocatheter125 that may be inserted into thecatheter30 and advanced to the blood clot C. Aballoon108 may be positioned over thecatheter30 as described above. Thesieve mechanism120 may include openings that are large enough to pass blood cells but small enough for the debris (clot C) to be captured by thesieve mechanism120. As themechanism120 is withdrawn through thecatheter30, clot C is removed from the CSF space.

As shown inFIG. 34, in another embodiment, thereceptacle105 may include a plurality ofmicrowires115, which may have pressure sensors126 positioned on, in, or about thecatheter30. The pressure sensors126 help detect problems in the overall flow circuit, and highlight when there is a blockage. A balloon (not shown) may be positioned over thecatheter30 as described above and the balloon may further be used to deployflexible pressure sensors127. In other embodiments, theflexible pressure sensors127 may be printed on a substrate (e.g., silicone) and deployed at or near the blood clot C.

Balloons

As can be understood fromFIGS. 35-38, in some embodiments, thesystem5 orcatheter30 may be used with other devices to help increase the efficiency and safety of the neuropheresis system. For example, and as shown inFIGS. 35 and 36, in one embodiment, apositioning device130 with multiple inflatable/deflatable balloons135, each of which may have its own lumen and/orport130a, can be inserted through the introducer sheath20 (not shown) and directly into the spinal canal. Theballoons135 may be co-located with or disposed about thepositioning device130. In one embodiment, theballoon135 has a length between approximately 0.5 cm and approximately 2.0 cm and a height between approximately 0.25 cm and approximately 0.6 cm. In some embodiments, theballoons135 may be radiopaque to provide increased visualization of thecatheter30 orpositioning device130 within the CSF space.

As depicted inFIGS. 37 and 38, the positioning device's first (distal-most 135a) and second (next to first135b) balloons may be inflated to push tissue structures back; thesecond balloon135bcan then be deflated, so that thecatheter30 can be advanced into the space that was occupied by tissue and nerves, before it was pushed back by thesecond balloon135b. Thefirst balloon135ais deflated, and the deflated balloons are advanced further into theCSF space15, where they are reinflated. This process is repeated until thecatheter30 is in the desired position in the spinal column, at which point thepositioning device130 can be withdrawn.

Multiple Lumens and Other Features of the Catheter

In some embodiments, thesystem5 includes a multi-lumen (e.g. more than one lumen)catheter30. A multi-lumen catheter can provide stability under a vacuum. The lumens themselves can provide redundancy such that, if one gets clogged, other lumens may be utilized. The lumens enable real-time sampling and spinal pressure measurement, thus enabling action to be taken if pressure is too high or too low which indicates blockage and/or overdrainage. In some embodiments, the diameter of the distal end is smaller (e.g., 4 French (4F)) than the diameter of the proximal end in order to maintain flow despite the lack of space in the cervical region of the spine. In some embodiments, the diameter of the proximal end is greater than the diameter of the distal end to enable rapid drainage of large amounts of blood-filled CSF quickly. The catheters are constructed to maintain patency despite anatomical challenges, such as being squeezed by tissue in the dura or being subject to a large suction force from the pump on the walls of the catheter. In some embodiments, the catheter includes a cross sectional area of approximately 0.8 mm²to enhance flow and a round distal section to facilitate cervical placement via a guidewire. In some embodiments, the separation between the inlet and outlet is between approximately 33 cm and approximately 38 cm to reduce likelihood of local recirculating loops and enhance rapid clearing of a large amount, up to and including substantially all, of the entire volume of CSF.

In some embodiments, the inlet and outlet of the catheter are switched. For example, in a subarachnoid hemorrhage (SAH), there is often a bolus of bloody CSF at the base of the brain, which can leak into the spine over time. When the therapy is deployed and fluid is being moved at the rate of about 120/240 ml/hr (or any other desired rate), it may be helpful from time to time to switch the inlet and outlet of catheter (particularly if a short catheter is being used) to prevent local recirculation of fluid and enhance unfiltered CSF being drawn into the filter. Other therapeutic uses of switching the inlet and outlet includes use in a method of preventing stagnating flow, dislodging clots, and/or opening up blockages, which may be due to thick blood or suction effects on the inlet. In one embodiment, two microcatheters may be used within a central lumen to change the position of inlet and outlet. In other embodiments, an outer sheath with cut-outs or openings may be used to change the position of the inlet and outlet. Such a feature may also make clot-removal from within the catheter easier without having to extract the catheter and place it again.

In some embodiments, the catheter having a tubular body may include a plurality of openings over at least a portion of the tubular body. A sheath configured to cover certain openings on the tubular body may be used such that the catheter remains in place while the sheath is rotated to open or close the openings in the tubular body to increase or decrease flow as needed.

FIGS. 39 through 57 illustrate various embodiments of acatheter30 that may be used with the present systems.FIGS. 39 through 42 illustrate embodiments of acatheter30 having proximal and distal ends with varying diameters. More specifically,FIG. 39 andFIG. 40 illustrate one embodiment of a5F catheter30 having aproximal end200 with different dimensions than adistal end250 of the catheter. As shown inFIG. 39, theproximal end200 of thecatheter30 includes anouter lumen205 and aninner lumen210. Theouter lumen205 is defined by aninner wall205a, andouter wall205band amiddle wall205c. Other embodiments may include greater or fewer walls. Theouter wall205bmay be a55D polyether block amide (e.g., a polyether block amide sold under name PEBAX) 5F approximately 0.003″ wall jacket. Theouter wall205bmay have a diameter D₁of about 0.065″ or about 0.17 cm. Themiddle wall205cmay be about an approximately 0.001″×0.003″ braid. Theinner wall205amay be a PTFE etching approximately 0.058″ ID×0.0015″ wall liner having a diameter D₂of about 0.058″ or about 0.15 cm. Theinner lumen210 is defined by aninner wall210band anouter wall210a. Theouter wall210amay be a55D polyether block amide 3F approximately 0.003″ wall having a diameter D₃of about 0.038″ or about 0.10 cm. Theinner wall210b, may have a diameter D₄of about 0.033″ or about 0.08 cm. As shown inFIG. 40, thedistal end250 of thecatheter30 includes anouter lumen260 defined by anouter wall260a, aninner wall260b, and amiddle wall260c. Other embodiments may include greater or fewer walls. Theouter wall260amay be a55D polyether block amide 4F approximately 0.005″ wall jacket having a diameter D₁of about 0.054 in or about 0.14 cm. Themiddle wall260cmay be an approximately 0.001″×0.003″ braid. Theinner wall260bmay be a PTFE etched approximately 0.042″×0.0015″ wall liner having a diameter D₂of about 0.041″ or about 0.10 cm.

FIG. 41 andFIG. 42 illustrate one embodiment of a6F catheter30 having aproximal end300 with different dimensions than adistal end350 of the catheter. As shown inFIG. 41, theproximal end300 of thecatheter30 includes anouter lumen305 and aninner lumen310. Theouter lumen305 is defined by aninner wall305a, anouter wall305b, and amiddle wall305c. Other embodiments may include greater or fewer walls. Themiddle wall305cmay be an approximately 0.001″×0.003″ braid. Theouter wall305bmay be a55D polyether block amide 6F approximately 0.003″ wall jacket. Any other suitable material and dimensions also may be used. Theouter wall305bmay have a diameter D₁of about 0.078″ or about 0.20 cm. Theinner wall305amay be a PTFE etching approximately 0.068″ ID×0.0015″ wall liner having a diameter D₂of approximately 0.068″ or approximately 0.17 cm. Theinner lumen310 is defined by aninner wall310band anouter wall310a. Theouter wall310amay be a55D polyether block amide 3F approximately 0.003″ wall having a diameter D₃of about 0.038″ or about 0.10 cm. Theinner wall310bmay have a diameter D₄of about 0.033″ or about 0.08 cm. As shown inFIG. 42, thedistal end350 of thecatheter30 includes anouter lumen360 defined by anouter wall360a, aninner wall360b, and amiddle wall360c. Other embodiments may include greater or fewer walls. Theouter wall360amay be a55D polyether block amide 4F approximately 0.005″ wall jacket having a diameter D₁of about 0.054″ or about 0.14 cm. Themiddle wall360cmay be an approximately 0.001″×0.003″ braid. Theinner wall360bmay be a PTFE etched approximately 0.042″×0.0015″ wall liner having a diameter D₂of about 0.041″ or about 0.10 cm. Any other suitable material and dimensions also may be used.

FIGS. 43 through 57 depict other embodiments of thecatheter30 having multiple lumens.FIGS. 43 and 44 depict acatheter30 configured for use as a peripherally inserted central catheter (PICC) having aninlet lumen400aand anoutlet lumen400b. The inlet lumen400ahas a surface area of about 0.00084 in²and a diameter D₁of about 0.022 in. Theoutlet lumen400bhas a surface area of 0.00084 in²and a diameter D₂of about 0.022 in. The inlet and outlet lumens are defined by anouter wall405 and amiddle wall410. The thickness T_oof theouter wall405 is about 0.010″. The thickness T_Mof themiddle wall410 is about 0.004″. Any other suitable material and dimensions also may be used.

FIGS. 45 through 47 depict adual lumen catheter30 having aninlet lumen415aand anoutlet lumen415b. The inlet lumen415ahas a surface area of about 0.00115 in²and a diameter D₁of about 0.023″. Theoutlet lumen415bhas a surface area of about 0.000314 in.²and a diameter D₂of about 0.020 in. The inlet and outlet lumens are defined by anouter wall420 and amiddle wall425. The thickness T_oof theouter wall420 is about 0.008″. The thickness T_Mof themiddle wall425 is about 0.004″. The radius of curvature R₁of theinlet lumen415ais about 0.005″. The radius R₂of the outlet lumen is about 0.014″. The diameter D_Cof thecatheter30 is about 0.065″. Any other suitable material and dimensions also may be used.

FIGS. 48 through 50 depict amulti-lumen catheter30 having threeinlet lumens430aand anoutlet lumen430b. Other embodiments may include a greater number of inlet or outlet lumens. Theinlet lumens430ahave a total surface area of about 0.00144 in²and each has a diameter D₁of about 0.012 in. Theoutlet lumen430bhas a surface area of about 0.00031 in²and a diameter D₂of about 0.020 in. The inlet and outlet lumens are defined by anouter wall435 and amiddle wall440. The thickness T_oof theouter wall435 is about 0.006″. The thickness T_Mof themiddle wall440 is about 0.004″. The radius R₁of theinlet lumen430ais about 0.013″. The radius R₂of theoutlet lumen430bis about 0.027″. The diameter D_Cof thecatheter30 is about 0.065″. Any other suitable material and dimensions also may be used.

FIGS. 51 through 53 depict amulti-lumen catheter30 having twoinlet lumens445aand anoutlet lumen445b. Other embodiments may include a greater number of inlet or outlet lumens or the inlet and outlet lumens may be positioned differently relative to each other. Theinlet lumens445ahave a total surface area of about 0.0013 in²and each has a diameter D₁of about 0.022″. Theoutlet lumen445bhas a surface area of about 0.00065″ in²and a diameter D₂of about 0.022″. The inlet and outlet lumens are defined by anouter wall450 and amiddle wall455. The thickness T_oof theouter wall450 is about 0.006″. The thickness T_Mof themiddle wall455 is about 0.004″. The radius R₁of theinlet lumen445ais about 0.027″. The radius R₂of theoutlet lumen445bis about 0.027″. The diameter D_Cof thecatheter30 is about 0.065″. Any other suitable material and dimensions also may be used.

FIGS. 54 through 57 depict adual lumen catheter30 having aninlet lumen460aand anoutlet lumen460b. The inlet lumen460ahas a surface area of about 0.00151 in²and a diameter D₁of about 0.044″. Theoutlet lumen460bhas a surface area of about 0.00038 in²and a diameter D₂of about 0.022″. The inlet and outlet lumens are defined by anouter wall465 and amiddle wall470. The thickness T_oof theouter wall465 is about 0.0065″. The thickness T_Mof the middle orinner wall470 is about 0.003″. The diameter D_Cof thecatheter30 is about 0.065″. As shown inFIGS. 56 and 57, and discussed in more detail above, theinlet lumen460aandoutlet lumen460bmay optionally include one ormore openings80 along certain portions of the catheter to increase the CSF or other fluid flow through thesystem5.FIGS. 56 and 57 illustrate oneopening80 in each of the inlet and outlet lumens for clarity but it is understood that each lumen may include one ormore openings80. Theopenings80 may be elongated openings defined within the outercircumferential wall462aof theinlet lumen460aand/or in the outercircumferential wall462bof theoutlet lumen460b. Theopenings80 may be of oval, elliptical, other, or undefined shape. In some embodiments, the one ormore openings80 defined in the outercircumferential wall462aof theinlet lumen460ahas a total cross sectional surface area of approximately 0.00126 in²and the size of eachindividual opening80 is approximately 0.022″×0.062″. The one ormore openings80 defined in the outercircumferential wall462bof theoutlet lumen460bhas a total cross sectional surface area of approximately 0.000314 in²and the diameter of eachindividual opening80 is approximately 0.020 in. Any other suitable material and dimensions also may be used.

FIGS. 58 and 59 are surface area comparison charts.FIG. 58 shows a comparison of the distal/outlet lumens of the catheters of the present disclosure in comparison to the surface area of the distal/outlet lumens of known catheters.FIG. 59 shows a comparison of the proximal/inlet lumens of the catheters of the present disclosure in comparison to the surface area of the proximal/inlet lumens of known catheters.

FIGS. 60-66,67-71, and72-75 illustrate overall views, proximal subassembly views, and distal subassembly views, respectively, of an embodiment of acatheter500 according to certain implementations.FIG. 60 illustrates a Y-connector portion502, aproximal subassembly540, and adistal subassembly560. The Y-connector portion502 may include

connectors

504,506, features508,510,512,position marker514, and other components. The

connectors

504,506 may take various forms. For example, as illustrated, the

connectors

504,506 are female and male Luer-lock connectors, respectively. The

features

508,510,512 may be strain relief and kink resistance features, for example, as described above with reference to strain relief and kinkresistance feature60. Thefeature508 may be configured to allow flex or deformation of thecatheter500 at portions near a central meeting point of the Y-connector502. The

features

510,512 may be configured to allow flex or deformation of thecatheter500 near the

connectors

504,506. In certain implementations, the

features

510,512 may be color coded to indicate to which lumen of a multi-lumen catheter, the

connectors

504,506, correspond. In certain embodiments, the

features

508,510,512 may take the form of approximately ⅛″ polyolefin heat shrink tubing. Theposition marker514 may be a position marker as described above with reference toposition marker100.

The length L₁of thecatheter500 may be approximately 1,300 mm with a working length L₂of approximately 1,150 mm. The working length L₂may be defined based on various use and design considerations. As illustrated, the working length L₂is the distance from the distal end of thedistal subassembly560 to the distal end of thefeature508. The distance D₁from the distal end of thefeature508 to the proximal end of theconnector506 may be approximately 150 mm. Thefeature508 may have a length L₃of approximately 35 mm and the

features

510,512 may have a length L₄of approximately 7 mm. In certain implementations, thecatheter500 may have a length L₁of between approximately 400 mm and approximately 1200 cm, with the working length L₂and other measurements changed accordingly.

FIG. 61 illustrates a sectional view taken from the region of thecatheter500 marked with cutting plane line A-A. This view illustrates alumen516A defined by awall516B. The characteristics and properties of thelumen516A andwall516B may be similar to the other walls and lumens described herein. As illustrated, thewall516B has an inner diameter D₂of approximately 0.54 mm and an outer diameter D₃of approximately 1.14 mm.

FIG. 62 illustrates a sectional view taken from the region of thecatheter500 marked with cutting plane line B-B. This view illustrates alumen518A defined by aninner wall518B and alumen520A defined by the space between theinner wall518B and anouter wall520B. The characteristics and properties of the

lumens

518A,520A and the

walls

518B,520B may be similar to the other walls and lumens described herein. Theinner wall518B may have an inner diameter D₄of approximately 0.56 mm and an outer diameter D₅of approximately 0.71 mm. Theouter wall520B may have an inner diameter of approximately 1.32 mm and an outer diameter of approximately 1.689 mm.

FIG. 63 illustrates an enlarged, detail view of a portion of the Y-connector502 according to certain implementations, includingtubes522,first branch524, andsecond branch526. Thetubes522 may be hypotubes or other lengths of tubing. Thetubes522 may have a length L₅of approximately 10 mm. In certain implementations, thefirst branch524 may place theconnector504 in fluid connection with thelumen520A and thesecond branch526 may place theconnector506 in fluid connection with thelumen518A.

FIG. 64 illustrates the location of twoposition markers514 on thecatheter500. The distal end of thefirst position marker514 is located a distance D₉of approximately 450 mm away from the distal end of thecatheter500. The distal end of thesecond position marker514 is located a distance D₈of approximately 550 mm away from the distal end of thecatheter500. The length L₄of theposition markers514 is approximately 10 mm. In certain implementations, the bands and/or position markers (such as position markers514) may comprise PET heat shrink tubing.

FIG. 65 illustrates a sectional view taken from the region of thecatheter500 marked with the cutting plane line J-J. This view illustrates an embodiment wherein an outer portion of theposition marker514 is substantially adjacent to an inner portion of thewall520B. Accordingly, in this portion of this embodiment, thelumen520A is defined by the outer portion of thewall518B and the inner portion of theposition marker514. As illustrated, theouter wall520B has an outer diameter D₁₀of approximately 1.75 mm.

FIG. 66 illustrates a portion of thecatheter500 near the joining of theproximal subassembly540 and thedistal subassembly560, including

bands

528A,528B,530, openings532, and a radiused tip534. The distal portion of theband530A may be located a distance D₁₁of approximately 300 mm away from the distal portion of theband528A. The distal end of theband528A may be located a distance D₁₂of approximately 2 mm away from the distal end of the radiusedtip530. The radiused tip may have a radius R₁of approximately 0.28 mm.

FIG. 67 illustrates a portion of theproximal subassembly540. As illustrated, the distance D₁from the distal end of theproximal subassembly540 to the proximal end of theproximal subassembly540 is approximately 893 mm. The distance D₂from a distal end of amarker band544B to a distal end of aband530A is approximately 248 mm. A distance D₄from a proximal end of theproximal subassembly540 to the distal end of aband530B is approximately 845 mm. A distance D₃from a distal end of themarker band544A to a distal end of theband530A is approximately 148 mm. The

marker bands

544A,544B may have a length L₁of approximately 10 mm. A portion of theproximal subassembly540 may comprise coiledwire542A having a coil pitch of approximately 0.018″. A portion of theproximal subassembly540 may comprise coiledwire542B having a coil pitch of approximately 0.095″. In certain implementations, the

wires

542A,542B may comprise approximately 0.003″ round wire spool of 304V spring temper material.

In certain implementations, theproximal subassembly540 of thecatheter500 may have an outer diameter of between approximately 0.06″ and approximately 0.07″. This configuration may maximize the size of the catheter between layers of tissue to enable a desired level of drainage and/or suction without collapse. The thickness of theproximal subassembly540 and other sections of thecatheter500 may be a function of a design of one or more layers of coil and sheath. The thickness may affect the stiffness and pushability of thecatheter500 and kink-resistance. In certain implementations, the diameter of an inner lumen of the catheter500 (such as the diameter of a lumen of the proximal subassembly540) may be chosen to provide optimum drainage and/or suction given the constraints of particular anatomy or procedures. For example, the minimum diameter of a proximal inner lumen may be chosen to be between approximately 0.025″ and approximately 0.060″.

FIG. 68 illustrates a detail view of theproximal subassembly540 ofFIG. 67. As illustrated, a portion of theproximal subassembly540 defines a plurality ofopenings532A. Theopenings532A may be in fluid connection with a lumen of thecatheter500. Theopenings532A may be spaced with 2 coil pitch spacing of thewire542A. The distance D₆between the distal end of theband530B and the distal end of theband530A is approximately 45 mm. A distance D₅from the distal end of theband530A to the distal end of theproximal subassembly540 may be approximately 3 mm. In certain implementations, the

bands

530A,530B may comprise a PT/10% IR band having an inner diameter of approximately 0.061″ and an outer diameter of approximately 0.064″.

FIG. 69 illustrates a sectional view taken from the region of theproximal subassembly540 marked with the cutting plane line A-A, including aliner546 andtubing548. Theliner546 and thetubing548 may be arranged such that thetubing548 is within theliner546. In certain implementations, the liner456 may comprise approximately 0.001″ WT PTFE liner. Thetubing548 may comprise approximately 0.004″ WT polyether block amide tubing. The outer diameter D₇of thecombination tubing548 andliner546 may be approximately 1.69 mm. The inner diameter D₈of the same may be approximately 1.32 mm.

FIG. 70 illustrates a detail view of a portion of theproximal subassembly540 taken from the view of line D-D and illustrating one of theopenings532A. The illustratedopening532A has dimensions of approximately 1.57 mm by approximately 0.56 mm.

FIG. 71 illustrates a sectional view taken from the region of theproximal subassembly540 marked with the cutting plane E-E. As illustrated the outer diameter D₉this portion, inclusive ofmarker band544 is approximately 1.75 mm.

FIG. 72 illustrates a portion of thedistal subassembly560. The length L₁of thedistal subassembly560 may be approximately 302 mm. The distance D₁from the proximal end of thedistal subassembly560 to the distal end of aband528B is approximately 270 mm. A portion of thedistal subassembly560 may comprise a coiled wire462B may have a coil pitch of approximately 0.032″. This and other portions of thecatheter500 may comprise approximately 0.003″WT nylon 12 tubing having an inner diameter of approximately 0.022″ and approximately 0.007″ WT PEBAX tubing having an inner diameter of approximately 0.04″.

FIG. 73 illustrates a detailed portion of thedistal subassembly560, including theband528A, a plurality ofopenings532B, theband528B, a wire462A, and the wire462B. In certain implementations, the wires462A,462B may be different portions of the same wire or may be separate sections of wire. As illustrated, the wire462A and462B may be separated byband528B. The wire462A may have a coil pitch of approximately 0.065″. The wires462A,462B may comprise approximately 0.003″ round wire spool 304V spring temper material. Theopenings532B may be spaced with 2 coil pitch spacing and arranged on a top and a bottom portion of thecatheter500 and made a fluid connection with an inner lumen of thecatheter500. A distance D₂between the distal end of theband528B and the distal end of theband528A may be approximately 30 mm. The wire462A may be disposed within this region. The

bands

528A,528B may have an inner diameter of approximately 0.032″ and an outer diameter of approximately 0.034″. The

bands

528A,528B may comprise a material of PT/10% IR.

FIG. 74 illustrates a detailed portion of thedistal subassembly560, including the radiusedtip530, theband528A, and the wire462A. The distance from the distal end of theband528A and the distal end of the radiusedtip530 is approximately 2 mm. The radiused tip may have a radius R₁of approximately 0.28 mm.

FIG. 75 illustrates a sectional view taken from the region of thedistal subassembly560 marked with the cutting plane A-A. As illustrated, this section of thedistal subassembly560 has an outer diameter of approximately 1.14 mm and an inner diameter of approximately 0.53 mm.

All directional references (e.g., proximal, distal, upper, lower, upward, downward, left, right, lateral, front, back, top, bottom, above, below, vertical, horizontal, clockwise, and counterclockwise) are only used for identification purposes to aid the reader's understanding of the present invention, and do not create limitations, particularly as to the position, orientation, or use of the invention. Connection references (e.g., attached, coupled, connected, and joined) are to be construed broadly and may include intermediate members between a collection of elements and relative movement between elements unless otherwise indicated. As such, connection references do not necessarily infer that two elements are directly connected and in fixed relation to each other. It should be noted that delivery sheath and delivery catheter may be used interchangeably for purposes of this description. The exemplary drawings are for purposes of illustration only and the dimensions, positions, order and relative sizes reflected in the drawings attached hereto may vary.

The above specification, examples and data provide a complete description of the structure and use of exemplary embodiments of the invention as claimed below. Although various embodiments of the invention as claimed have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the spirit or scope of this invention. Other embodiments are therefore contemplated. It is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative only of particular embodiments and not limiting. Changes in detail or structure may be made without departing from the basic elements of the invention as defined in the following claims.

Claims

What is claimed is:

1. A system for access and navigation of a cerebrospinal fluid (CSF) space, the system comprising

an introducer sheath configured to access and align with the cerebrospinal fluid space;

an introducer coupled to a proximal end of the introducer sheath; and

a catheter having multiple lumens that is configured to be received in the introducer,

wherein, the catheter is configured to be positioned to access and navigate the cerebrospinal fluid space upon delivery of the catheter through the introducer and the introducer sheath.

2. The system ofclaim 1, wherein the introducer is configured to enable the catheter to make a bend having a radius of between approximately 0 mm and approximately 10 mm.

3. The system ofclaim 2, wherein the introducer is configured to enable the catheter to make a bend having a radius of between approximately 1 mm and approximately 10 mm.

4. The system ofclaim 3, wherein the catheter includes a spring loaded tip in a pre-deployed position during delivery through the introducer sheath and in a deployed position after exiting the introducer sheath.

5. The system ofclaim 1, further comprising at least two transducers positioned on or about the catheter, wherein at least one transducer is a pressure sensor and at least one transducer is a flow sensor.

6. The system ofclaim 1, wherein the introducer comprises a plurality of ports, each of the plurality of ports including a check valve operably associated therewith.

7. The system ofclaim 1, further comprising a strain relief and kink resistance feature formed as a sleeve and disposed on the catheter.

8. The system ofclaim 7, wherein the strain relief and kink resistance feature is a coiled wire embedded in a tube constructed from medical grade catheter material.

9. The system ofclaim 8, wherein said medical grade catheter material is flexible.

10. The system ofclaim 7, wherein the strain relief and kink resistance feature is a braided wire embedded in a tube constructed from medical grade catheter material.

11. The system ofclaim 1, further comprising a plurality of openings defined within an outer circumferential wall of the catheter to increase fluid flow through the system.

12. The system ofclaim 11, wherein the plurality of openings has a total cross-sectional surface area of at least approximately 0.6 mm².

13. The system ofclaim 11, wherein the plurality of openings is positioned generally linearly along or parallel to a horizontal line defined through a central lumen of the catheter.

14. The system ofclaim 8, wherein the plurality of openings is positioned in a staggered or symmetrical pattern relative to a horizontal line defined through a central lumen of the catheter.

15. The system ofclaim 1, further comprising a receptacle to capture and retrieve blood clots within the CSF space upon deployment from a distal end of the catheter, the receptacle configured for delivery through the introducer sheath and the catheter into the CSF space.

16. The system ofclaim 15 wherein the receptacle comprises a coiled microwire configured for delivery through the catheter to capture and retrieve a blood clot within the CSF space.

17. The system ofclaim 15 wherein the receptacle comprises a plurality of intertwined microwires configured for delivery through the catheter to capture and retrieve a blood clot within the CSF space.

18. The system ofclaim 15 wherein the receptacle comprises a sieve coupled to a distal end of a micro-catheter and configured for delivery through the catheter to capture and retrieve a blood clot within the CSF space.

19. The system ofclaim 1, further comprising a positioning device comprising a plurality of lumens and a plurality of balloons, each balloon positioned in an individual lumen, each balloon configured to be in a deflated state during delivery of the positioning device through the introducer sheath and configured to transition from a deflated state to an inflated state and back to a deflated state during advancement into the CSF space.

20. The system ofclaim 1, wherein the cerebrospinal fluid space is a space where cerebrospinal fluid flows around a ventricle of the brain.

21. The system ofclaim 1, wherein the cerebrospinal fluid space is a space where cerebrospinal fluid flows around a spinal column.

22. The system ofclaim 1, further comprising one or more openings defined within an outer circumferential wall one of an inlet lumen or an outlet lumen of the catheter to increase fluid flow through the system.

23. The system ofclaim 19, wherein at least one of the one or more openings defined within the outer circumferential wall of the inlet lumen has a total cross-sectional surface area of less than 0.01 inches².

24. The system ofclaim 19, wherein at least one of the one or more openings defined within the outer circumferential wall of the outlet lumen has a total cross-sectional surface area of approximately 0.01 inches².

25. The system ofclaim 1, wherein the catheter has a length of between approximately 40 cm and approximately 120 cm.

26. The system ofclaim 1, wherein the catheter is configured to bend without kinking or compromising flow within the catheter.

27. The system ofclaim 26, wherein the catheter is configured to bend without kinking or compromising flow by comprising a coiled wire having a coil pitch between approximately 0.01 inches and approximately 0.03 inches.

28. A method of accessing and navigating a cerebrospinal fluid (CSF) space, the method comprising

introducing an introducer sheath aligning the introducer sheath with the CSF space;

deploying a catheter having multiple lumens into the introducer sheath through a multi-port introducer coupled to a proximal end of the introducer sheath, the catheter having at least two transducers positioned on or about the catheter, wherein at least one transducer is a pressure sensor and at least one transducer is a flow sensor;

delivering the catheter through an access site in the CSF space created by the introducer sheath; and

positioning the catheter to access and navigate the CSF space.

29. The method ofclaim 28, wherein the CSF space is a space where cerebrospinal fluid flows around a ventricle of the brain.

30. The method ofclaim 28, wherein the CSF space is a space where cerebrospinal fluid flows around a spinal column.

31. The method ofclaim 28, wherein the catheter has a length of between approximately 40 cm and approximately 120 cm; and wherein the catheter comprises an inlet opening and an outlet opening, the inlet opening and the outlet opening having a spacing of between approximately 10 cm and approximately 30 cm.

32. The method ofclaim 28, wherein the multiple lumens comprise a first lumen defined by an inner wall and a second lumen defined between the inner wall and an outer wall.

33. The method ofclaim 32, wherein the inner wall has an inner diameter of approximately 0.56 mm and an outer diameter of approximately 0.71 mm and the outer wall has an inner diameter of approximately 1.32 mm and an outer diameter of approximately 1.689 mm.

34. The method ofclaim 32, wherein the catheter comprises a coiled wire having a coil pitch selected to enable the catheter to be deployed and positioned without kinking or compromising flow within the catheter and to enable catheter unblocking.

35. The method ofclaim 34, wherein the coil pitch is between approximately 0.01 inches and approximately 0.03 inches.