SYSTEMS AND METHODS FOR SHUNTING FLUID
Systems and methods are provided herein that generally involve shunting fluid, e.g., shunting cerebrospinal fluid in the treatment of hydrocephalus. Self-cleaning catheters are provided which include split tips configured such that pulsatile flow of fluid in a cavity in which the catheter is inserted can cause the tips to strike one another and thereby clear obstructions. Catheters with built-in flow indicators are also provided. Exemplary flow indicators include projections that extend radially inward from the interior surface of the catheter and which include imageable portions (e.g., portions which are visible under magnetic resonance imaging (MRI)). Movement of the flow indicators caused by fluid flowing through the catheter can be detected using MRI, thereby providing a reliable indication as to whether the catheter is partially or completely blocked.
1 . A catheter for shunting fluid built up within a skull of a patient, comprising:
an elongate tubular body having proximal and distal ends;
first and second flexible tips extending from the distal end of the elongate body and having one or more fluid passageways extending therethrough;
a plurality of fluid ports formed in the first and second tips; and
a coupling member configured to hold the first and second tips in a position adjacent to one another.
2 . The catheter of claim 1 , wherein the first and second flexible tips are sized and configured for placement in a brain ventricle.
3 . The catheter of claim 1 , wherein the coupling member comprises a peelable sheath disposed around the first and second tips.
4 . The catheter of claim 1 , wherein the coupling member comprises a seamlessly removable insertion sheath disposed around the first and second tips.
5 . The catheter of claim 1 , wherein the coupling member comprises a bioabsorbable adhesive disposed between the first and second tips.
6 . The catheter of claim 1 , wherein the coupling member comprises a stylet or cannula disposed around the first and second tips.
7 . The catheter of claim 1 , wherein the first and second tips each have a D-shaped cross-section.
8 . The catheter of claim 7 , wherein the first and second tips together form a circular cross-section when coupled to one another by the coupling member.
9 . The catheter of claim 1 , wherein the first and second tips each have a circular cross-section.
10 . The catheter of claim 1 , wherein the plurality of fluid ports are formed in a helical pattern through sidewalls of the first and second tips.
11 . The catheter of claim 1 , wherein pulsatile flow of fluid in which the first and second tips are disposed is effective to cause the first and second tips to strike one another, thereby dislodging obstructions from the first and second tips.
12 . The catheter of claim 1 , further comprising a plurality of shrouds, each shroud being disposed over a respective one of the plurality of fluid ports.
13 . The catheter of claim 12 , wherein the plurality of shrouds are formed as hollow quarter spheres.
14 . The catheter of claim 1 , wherein at least one of the first and second tips includes an embedded microsensor.
15 . The catheter of claim 14 , wherein the embedded microsensor comprises at least one of an interrogatable sensor, a pressure sensor, a tilt sensor, an accelerometer sensor, a glutamate sensor, a pH sensor, a temperature sensor, an ion concentration sensor, a carbon dioxide sensor, an oxygen sensor, and a lactate sensor.
16 . The catheter of claim 14 , wherein the embedded microsensor is a pressure sensor that supplies an output indicative of a pressure in the environment surrounding the first and second tips to a valve to control a fluid flow rate through the valve.
17 . The catheter of claim 1 , wherein at least one of the first and second tips contains a quantity of a drug, is coated with a drug, or is impregnated with a drug.
18 . The catheter of claim 17 , wherein the drug comprises at least one of an antibacterial agent, an anti-inflammatory agent, a corticosteroid, and dexamethasone.
19 . The catheter of claim 1 , wherein the first and second tips are formed from a polymeric composition.
20 . A shunt for draining fluid built up within a skull of a patient, comprising:
the catheter of claim 1 ;
a skull anchor coupled to the proximal end of the elongate tubular body, the skull anchor including an injection port through which fluid can be supplied to or withdrawn from the elongate tubular body;
a drain catheter extending from the skull anchor; and
a pressure-actuated valve disposed in line with at least one of the catheter and the drain catheter.
21 . A method of shunting body fluid, comprising:
inserting a catheter having first and second flexible tips extending from a distal end thereof and coupled to one another into a fluid-containing cavity such that fluid can flow out of the cavity through the catheter; and
decoupling the first and second tips such that pulsatile flow of fluid within the cavity causes the first and second tips to strike one another, thereby dislodging obstructions from the first and second tips.
22 . The method of claim 21 , wherein said decoupling comprises at least one of removing a sheath disposed around the first and second tips, removing a stylet or cannula disposed around the first and second tips, and exposing a bioabsorbable adhesive disposed between the first and second tips to the fluid.
23 . The method of claim 21 , further comprising adjusting a fluid flow rate through a valve in response to an output of a pressure sensor disposed on at least one of the first and second tips.
24 - 37 . (canceled)