Cerebrospinal fluid space draining catheters
Ventricular catheters and their methods of use are disclosed. In some embodiments, the disclosed ventricular catheters may reduce, or substantially prevent, obstruction of the catheter by astrocytes or other brain tissue due to adhesion and/or growth within the catheter. For example, in some embodiments, the holes and internal lumen of a ventricular catheter may be constructed such that the wall shear stresses applied within the holes and internal lumen of the catheter are greater than a threshold shear stress to prevent cell adhesion and growth within the catheter.
1 . A catheter comprising:
a tube; and
a plurality of holes disposed along a length of the tube and extending from an exterior surface to an internal lumen of the tube, wherein the plurality of holes and the internal lumen of the tube are configured such that a wall shear stress of the plurality of holes and the internal lumen due to cerebrospinal fluid flowing through the catheter with a predetermined flow rate is greater than a threshold shear stress to prevent cell adhesion and growth within the catheter.
2 . The catheter of claim 1 , wherein each hole has a hole transverse dimension and a depth, wherein at least one hole of the plurality of holes has a first depth that is different from a second depth of at least one of the remaining plurality of holes.
3 . The catheter of claim 2 , wherein the hole transverse dimension and depth of each hole are configured such that the wall shear stress within each hole is greater than the threshold under the predetermined flow rate through the catheter.
4 . The catheter of claim 2 , wherein the depth of each of the plurality of holes changes sequentially along an axial length of the catheter.
5 . The catheter of claim 1 , wherein an outer transverse dimension of the tube is different at locations associated with holes of the plurality of holes with different depths.
6 . The catheter of claim 1 , wherein an inner transverse dimension of the internal lumen is different at locations associated with holes of the plurality of holes with different depths.
7 . The catheter of claim 1 , wherein the plurality of holes are configured to provide a substantially uniform flow through adjacent holes.
8 . The catheter of claim 1 , wherein the predetermined flow rate is between or equal to 0.01 mL/min and 0.04 mL/min.
9 . The catheter of claim 1 , wherein the threshold shear stress is between or equal to 1 mPa and 10 mPa.
10 . The catheter of claim 1 , wherein a ratio of a minimum wall shear stress to a maximum wall shear stress of the catheter under the predetermined flow rate of cerebrospinal fluid is between or equal to 1 and 10.
11 . A method for draining cerebrospinal fluid from a cerebrospinal fluid space of a brain of a subject comprising:
inserting a catheter into a location fluidly connected to the cerebrospinal fluid space of the brain, wherein the catheter comprises a tube and a plurality of holes disposed along a length of the tube and extending from an exterior surface to an internal lumen of the tube; and
draining the cerebrospinal fluid from the cerebrospinal fluid space through the catheter, wherein draining the cerebrospinal fluid through the catheter applies wall shear stresses to the plurality of holes and the internal lumen that is greater than a threshold shear stress to prevent cell adhesion and growth within the catheter.
12 . The method of claim 11 , wherein each hole has a hole transverse dimension and a hole depth, wherein at least one hole of the plurality of holes has a first depth that is different from a second depth of at least one of the remaining plurality of holes.
13 . The method of claim 11 , wherein a flow through adjacent holes of the plurality of holes is substantially uniform.
14 . The method of claim 11 , wherein a flowrate through the catheter is between or equal to 0.01 mL/min and 0.04 mL/min.
15 . The method of claim 11 , wherein the threshold shear stress is between or equal to 1 mPa and 10 mPa.
16 . The method of claim 11 , wherein a ratio of a minimum wall shear stress to a maximum wall shear stress of the catheter is between or equal to 1 and 10.
17 . A catheter comprising:
a tube including one or more cylindrical portions; and
a plurality of holes disposed along a length of the tube and extending from an exterior surface to an internal lumen of the tube, each hole having a hole transverse dimension and a hole depth, wherein at least one hole of the plurality of holes has a first depth that is different from a second depth of at least one of the remaining plurality of holes wherein the plurality of holes are formed in the one or more cylindrical portions.
18 . The catheter of claim 17 , wherein the plurality of holes and the internal lumen are configured such that a wall shear stress of the plurality of holes and the internal lumen due to cerebrospinal flowing through the catheter with a predetermined flow rate is greater than a threshold shear stress to prevent cell adhesion and growth within the catheter.
19 . The catheter of claim 18 , wherein the predetermined flow rate is between or equal to 0.01 mL/min and 0.04 mL/min.
20 . The catheter of claim 18 , wherein the threshold shear stress is between or equal to 1 mPa and 10 mPa.
21 . The catheter of claim 18 , wherein a ratio of a minimum wall shear stress to a maximum wall shear stress of the catheter under the predetermined flow rate of cerebrospinal fluid is between or equal to 1 and 10.
22 . The catheter of claim 17 , wherein an outer transverse dimension of the catheter is different at locations associated with holes of the plurality of holes with different depths.
23 . The catheter of claim 17 , wherein the depths of the plurality of holes changes sequentially along an axial length of the tube.
24 . The catheter of claim 17 , wherein an inner transverse dimension of the internal lumen is different at locations associated with holes of the plurality of holes with different depths.
25 . The catheter of claim 17 , wherein the plurality of holes are configured to provide a substantially uniform flow through adjacent holes.