U.S. patent application number 17/062815 was filed with the patent office on 2021-04-01 for shunt flushers and related methods.
This patent application is currently assigned to Anuncia, Inc.. The applicant listed for this patent is Anuncia, Inc.. Invention is credited to PJ Anand, Ayesha Arzumand, Morgan Brophy, Andrew East, Greg Eberl, Loredana Guseila, Stela Moura, Deep Arjun Singh.
Application Number | 20210093844 17/062815 |
Document ID | / |
Family ID | 1000005276120 |
Filed Date | 2021-04-01 |
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United States Patent
Application |
20210093844 |
Kind Code |
A1 |
Anand; PJ ; et al. |
April 1, 2021 |
SHUNT FLUSHERS AND RELATED METHODS
Abstract
Systems and methods for flushing shunt systems are disclosed
herein. In some embodiments, a flusher includes a pinch tube that
extends over a flush dome such that a user can simultaneously close
the pinch tube and actuate the flush dome with a single motion.
Flushing and refill valves of the system can be disposed in a
cartridge that is laterally-offset from the flush dome,
advantageously reducing the height profile of the flusher. Flushers
with integrated shunt valves are also disclosed, as are shunt
systems with restricted and unrestricted modes for selectively
limiting the instances in which a user can open an auxiliary flow
path through the system.
Inventors: |
Anand; PJ; (Lowell, MA)
; Singh; Deep Arjun; (Cambridge, MA) ; Eberl;
Greg; (Acton, MA) ; East; Andrew; (Arlington,
MA) ; Brophy; Morgan; (Somerville, MA) ;
Arzumand; Ayesha; (North Billerica, MA) ; Moura;
Stela; (Lowell, MA) ; Guseila; Loredana;
(Lowell, MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Anuncia, Inc. |
Lowell |
MA |
US |
|
|
Assignee: |
Anuncia, Inc.
Lowell
MA
|
Family ID: |
1000005276120 |
Appl. No.: |
17/062815 |
Filed: |
October 5, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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15782247 |
Oct 12, 2017 |
10792480 |
|
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17062815 |
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62407810 |
Oct 13, 2016 |
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62500547 |
May 3, 2017 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61M 2202/0464 20130101;
A61M 27/006 20130101; A61M 5/14276 20130101; A61M 39/223 20130101;
A61M 2025/0019 20130101; A61M 2210/0693 20130101 |
International
Class: |
A61M 27/00 20060101
A61M027/00; A61M 39/22 20060101 A61M039/22 |
Claims
1.-41. (canceled)
42. A flusher comprising: a body that defines a collapsible flush
dome; a valve cartridge that houses a refill valve and a flush
valve, the valve cartridge being laterally-offset from the flush
dome; a passive flow path that extends between an upstream port and
a downstream port, at least a portion of the flow path being
defined by a collapsible fluid pathway that extends across an
exterior surface of the flush dome; wherein the flush valve has a
first position in which the flush dome is not in fluid
communication with the upstream port or the passive flow path and a
second position in which the flush dome is in fluid communication
with the upstream port and the passive flow path; wherein
application of a force to the collapsible fluid pathway is
effective to collapse the collapsible fluid pathway to block the
passive flow path and to collapse the dome to move the flush valve
to the second position and flush fluid through the upstream
port.
43. The flusher of claim 42, wherein the flush valve comprises a
valve body that is compressed against a valve seat by an adjustment
disc such that rotation of the adjustment disc is effective to
change a threshold opening pressure of the valve.
44. The flusher of claim 43, wherein the adjustment disc is
threadably mounted in the valve cartridge.
45. The flusher of claim 44, wherein the adjustment disc can be
actuated from a position outside of a patient in which the flusher
is implanted.
46.-56 (canceled)
57. A shunt system, comprising: a catheter having a primary flow
port and an auxiliary flow port; a flusher configured to emit a
flushing cough or pulse of fluid through the catheter; wherein the
shunt system is operable in a restricted mode in which a flush
generated by the flusher is insufficient to open the auxiliary flow
port and an unrestricted mode in which a flush generated by the
flusher is sufficient to open the auxiliary flow port.
58. The system of claim 57, wherein the flusher includes a control
operable to switch the flusher between the restricted mode and the
unrestricted mode.
59. The system of claim 58, wherein the control can be actuated
non-invasively.
60. The system of claim 58, wherein the control can be actuated
from a position outside of a patient in which the shunt system is
implanted.
61. The system of claim 58, wherein the control is
magnetically-actuated or hydraulically-actuated.
62. The system of claim 58, wherein the control comprises a
valve.
63. The system of claim 58, wherein the control adjusts a cracking
pressure of a flush valve of the flusher.
64. The system of claim 58, wherein the control adjusts an
effective volume of a flush cavity of the flusher.
65. The system of claim 64, wherein the control adjusts the
effective volume by selectively inflating or deflating an
inflatable member disposed within the flush cavity.
66. The system of claim 64, wherein the control adjusts the
effective volume by moving at least a portion of a sidewall of the
flush cavity.
67. The system of claim 64, wherein the control adjusts the
effective volume by selectively advancing or retracting a movable
member into or out of the flush cavity.
68. The system of claim 57, wherein the catheter includes a
plurality of auxiliary flow ports, each having a progressively
higher burst requirement.
69. The system of claim 57, wherein the catheter includes a
plurality of auxiliary flow ports, each covered by membranes having
progressively higher thicknesses.
70. The system of claim 58, wherein the control comprises a
compliant feature movable between a collapsed state and an expanded
state.
71. The system of claim 70, wherein the compliant feature includes
a passive flow path therethrough.
72. The system of claim 70, wherein the compliant feature is in
fluid communication with a flush emitted by the flusher, and
wherein the compliant feature moves to the expanded state to absorb
at least a portion of the flush when in the restricted mode.
73. The system of claim 70, wherein the control comprises at least
one valve that isolates the compliant feature from the flush
emitted by the flusher when in the unrestricted mode and that
places the compliant feature in fluid communication with the flush
when in the restricted mode.
74.-77. (canceled)
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 15/782,247, filed on Oct. 12, 2017. U.S.
patent application Ser. No. 15/782,247 claims priority to U.S.
Provisional Application No. 62/407,810 filed on Oct. 13, 2016 and
to U.S. Provisional Application No. 62/500,547 filed on May 3,
2017. The entire contents of these applications are incorporated by
reference herein.
FIELD
[0002] Shunt flushers and related methods are disclosed herein,
e.g., for use in shunting cerebrospinal fluid in the treatment of
hydrocephalus.
BACKGROUND
[0003] Shunt systems for transport of body fluids from one region
of the body to another region are generally known. For example,
shunt systems are often used in the treatment of hydrocephalus to
drain excess cerebrospinal fluid (CSF) from the ventricles of the
brain. A typical shunt system includes a one-directional,
pressure-controlled valve that is implanted beneath the skin. A
ventricular catheter extends from one side of the valve to the
ventricle. A drain catheter extends from the other side of the
valve to a drain site, such as the abdominal cavity.
[0004] After implantation and use over extended time periods, shunt
systems tend to become clogged in certain individuals. Clogging can
occur due to foreign materials which collect in the narrow tubular
passageways of the shunt system and in the inlet and outlet
openings of such passageways. Consequently, it is often necessary
to perform follow-on operations on an individual to remove the clog
or replace the entire system. The inconvenience, cost, and risk of
complications associated with these follow-on procedures are
considerable and undesirable. Accordingly, a need exists for
improved systems and methods for shunting fluid.
SUMMARY
[0005] Systems and methods for flushing shunt systems are disclosed
herein. In some embodiments, a flusher includes a pinch tube that
extends over a flush dome such that a user can simultaneously close
the pinch tube and actuate the flush dome with a single motion.
Flushing and refill valves of the system can be disposed in a
cartridge that is laterally-offset from the flush dome,
advantageously reducing the height profile of the flusher. Flushers
with integrated shunt valves are also disclosed, as are shunt
systems with restricted and unrestricted modes for selectively
limiting the instances in which a user can open an auxiliary flow
path through the system.
[0006] In some embodiments, a shunt system can include a catheter
having a primary flow port and an auxiliary flow port; and a
flusher configured to emit a flushing cough or pulse of fluid
through the catheter; wherein the shunt system is operable in a
restricted mode in which: (i) a flush generated by the flusher is
insufficient to open the auxiliary flow port; or (ii) the flusher
is prevented from emitting the flush; wherein the shunt system is
operable in an unrestricted mode in which: (i) a flush generated by
the flusher is sufficient to open the auxiliary flow port; or (ii)
the flusher is not prevented from emitting the flush; and wherein
the flusher includes a control operable to switch the flusher
between the restricted mode and the unrestricted mode.
[0007] The control can be configured such that it locks a flush
valve of the flusher in a closed position to operate in the
restricted mode and does not lock the flush valve in the closed
position to operate in the unrestricted mode. The control can be
configured such that it decreases an opening pressure threshold of
a flush valve of the flusher to operate in the restricted mode and
increases the opening pressure threshold of the flush valve to
operate in the unrestricted mode. The control can be configured
such that it reduces the pressure of the flush in the restricted
mode and increases the pressure of the flush in the unrestricted
mode. The control can reduce the pressure of the flush by placing a
flush dome of the flusher in communication with a first flush valve
having a lower opening pressure. The control can increase the
pressure of the flush by placing the flush dome in communication
with a second flush valve having a higher opening pressure. The
control can reduce the volume of the flush in the restricted mode
and increase the volume of the flush in the unrestricted mode. The
control can reduce the volume of the flush by limiting refill of a
flush dome of the flusher. The control can reduce the volume of the
flush by decreasing the effective volume of a flush dome of the
flusher. The control can decrease the effective volume by at least
one of: moving a divider within the flush dome, moving a
volume-occupying object into the flush dome, and expanding a
compartment within the flush dome. The control can be configured
such that it isolates the auxiliary flow port from the flush in the
restricted mode and does not isolate the auxiliary flow port from
the flush in the unrestricted mode. The catheter can include a
first fluid lumen in communication with the primary flow port and a
second fluid lumen in communication with the auxiliary flow port.
The control can select which of the first and second fluid lumens
of the catheter is in fluid communication with a flush dome of the
flusher. The control can be operable to selectively direct the
flush to one or more of an upstream port of the flusher and a
downstream port of the flusher.
[0008] In some embodiments, a shunt system can include a catheter
having a primary flow port and an auxiliary flow port; and a
flusher configured to selectively emit a first flush of fluid
through the catheter or a second flush of fluid through the
catheter; wherein the first flush of fluid is not sufficient to
open the auxiliary flow port and wherein the second flush of fluid
is sufficient to open the auxiliary flow port.
[0009] The second flush can have a higher pressure than the first
flush. The second flush can have a higher volume than the first
flush. The flusher can include first and second flush domes. The
first and second flush domes can be actuated simultaneously. The
flusher can emit the first flush by allowing fluid to escape from
the first flush dome without contributing to the flush. The flusher
can emit the second flush by including fluid in the first flush
dome in the flush. The flusher can emit the first flush when the
first flush dome is collapsed and can emit the second flush when
the second flush dome is collapsed. The system can include a
control that isolates the second flush dome from an upstream port
of the flusher to restrict opening of the auxiliary flow port. The
second flush dome can have a greater volume than the first flush
dome.
[0010] In some embodiments, a shunt system can include a catheter
having a primary flow port and an auxiliary flow port; a flusher
configured to selectively emit a flush of fluid through the
catheter; and a compliance feature in communication with a flush
path through the catheter; wherein the shunt system is operable in
a first mode in which the compliance feature expands during a
flushing operation to a degree sufficient to prevent a flush
emitted from the flusher from opening the auxiliary flow port; and
wherein the shunt system is operable in a second mode in which the
compliance feature does not expand during a flushing operation to a
degree sufficient to prevent a flush emitted from the flusher from
opening the auxiliary flow port.
[0011] The flusher can include a control configured to selectively
place the compliance feature in communication with the flush path.
The shunt system can operate in the second mode by physically
impeding expansion of the compliance feature. The shunt system can
include an extracorporeal member positionable over the compliance
feature when the compliance feature is implanted in a patient to
block expansion of the compliance feature.
[0012] In some embodiments, a ventricular shunt catheter can
include a primary flow port through which fluid can flow between an
exterior of the catheter and an interior of the catheter; and an
auxiliary flow port through which fluid can flow between an
exterior of the catheter and an interior of the catheter; wherein
the auxiliary flow port is initially closed to block fluid flow
therethrough and wherein the auxiliary flow port is selectively
openable to allow fluid to flow therethrough; wherein the auxiliary
flow port is configured to open in response to a non-invasive
extracorporeal input.
[0013] The catheter can include a clip that holds a shape memory
frame of the auxiliary flow port closed, and wherein the input
comprises actuating the clip. The clip can be actuated by applying
an electric current to the clip to break the clip or by applying a
magnetic field to the clip to move the clip.
[0014] In some embodiments, a shunt system can include a catheter
having: a primary flow port through which fluid can flow between an
exterior of the catheter and an interior of the catheter; and an
auxiliary flow port through which fluid can flow between an
exterior of the catheter and an interior of the catheter; wherein
the auxiliary flow port is initially closed to block fluid flow
therethrough and wherein the auxiliary flow port is selectively
openable to allow fluid to flow therethrough; a flusher configured
to emit a flush of fluid through a flush path of the catheter;
wherein the catheter has a first configuration in which the flush
of fluid is not effective to open the auxiliary flow port and a
second configuration in which the flush of fluid is effective to
open the auxiliary flow port; wherein the catheter changes from the
first configuration to the second configuration in response to an
input.
[0015] The input can be a non-invasive extracorporeal input. The
catheter can include a valve that isolates the auxiliary flow port
from the flush path and the input can include opening the valve.
The valve can be opened by directing a flush of fluid through the
catheter sufficient to open the valve. The input can be effective
to rupture a partition formed within the catheter between the
auxiliary flow port and the flush path. The input can be effective
to change an aperture size of a partition formed within the
catheter between the auxiliary flow port and the flush path. The
input can inflate a balloon of the catheter to open a flow path
between the flush path and the auxiliary fluid port. The input can
deflate a balloon of the catheter to open a flow path between the
flush path and the auxiliary flow port. The input can rotate a
sheath coaxially disposed with the catheter relative to the
catheter to uncover an auxiliary flow port. Rotating the sheath by
a first degree can align an opening of the sheath with the
auxiliary flow port and rotating the sheath by a second degree can
align the opening of the sheath with a second auxiliary flow port.
The input can translate a sheath coaxially disposed with the
catheter longitudinally with respect to the catheter to uncover an
auxiliary flow port. The catheter can include a sensor configured
to detect when the auxiliary flow port is opened. The catheter can
include a wire that reinforces the auxiliary flow port. The input
can include severing the wire or retracting the wire proximally
relative to the catheter.
[0016] In some embodiments, a flusher can include a body that
defines a collapsible flush dome; a valve cartridge that houses a
refill valve and a flush valve, the valve cartridge being
laterally-offset from the flush dome; a passive flow path that
extends between an upstream port and a downstream port, at least a
portion of the flow path being defined by a collapsible fluid
pathway that extends across an exterior surface of the flush dome;
wherein the flush valve has a first position in which the flush
dome is not in fluid communication with the upstream port or the
passive flow path and a second position in which the flush dome is
in fluid communication with the upstream port and the passive flow
path; wherein application of a force to the collapsible fluid
pathway is effective to collapse the collapsible fluid pathway to
block the passive flow path and to collapse the dome to move the
flush valve to the second position and flush fluid through the
upstream port.
[0017] The flush valve can include a valve body that is compressed
against a valve seat by an adjustment disc such that rotation of
the adjustment disc is effective to change a threshold opening
pressure of the valve. The adjustment disc can be threadably
mounted in the valve cartridge. The adjustment disc can be actuated
from a position outside of a patient in which the flusher is
implanted. The flush valve can have a predetermined fixed height or
positive stop such that the flush valve is compressed to a desired
amount of compression to yield a desired opening pressure. The
refill valve can have a first position in which the passive flow
path is not in fluid communication with the flush dome and a second
position in which the passive flow path is in fluid communication
with the flush dome. Collapsing the flush dome can be effective to
hold the refill valve in the first position. The flusher can
include a ventricular catheter in fluid communication with the
upstream port. The collapsible fluid pathway can include a pinch
tube attached to a trough formed in the exterior surface of the
flush dome, the pinch tube and the trough collectively defining an
inner lumen of a portion of the passive flow path. The cartridge
can include an upper chamber and a lower chamber separated by a
dividing wall. The flush valve and the refill valve can each
control fluid communication between the upper and lower chambers.
The upper chamber can be in fluid communication with the flush dome
via a first barbed fitting, the lower chamber can be in fluid
communication with the collapsible fluid pathway via a second
barbed fitting, and the lower chamber can be in fluid communication
with a ventricular catheter via a third barbed fitting. The
cartridge can be attached to the body by a first barbed fitting in
fluid communication with the flush dome and a second barbed fitting
in fluid communication with the collapsible fluid pathway. In some
embodiments, fluid can flow in the upstream port, through the
collapsible fluid pathway, and out of the downstream port without
flowing across any portion of the refill valve, the flush valve, or
the flush dome. The flusher can include a shunt valve disposed
within the cartridge or the downstream port.
[0018] In some embodiments, a shunt system can include a catheter
having a primary flow port and an auxiliary flow port; a flusher
configured to emit a flushing cough or pulse of fluid through the
catheter; wherein the shunt system is operable in a restricted mode
in which a flush generated by the flusher is insufficient to open
the auxiliary flow port and an unrestricted mode in which a flush
generated by the flusher is sufficient to open the auxiliary flow
port.
[0019] The flusher can include a control operable to switch the
flusher between the restricted mode and the unrestricted mode. The
control can be actuated non-invasively. The control can be actuated
from a position outside of a patient in which the shunt system is
implanted. The control can be magnetically-actuated or
hydraulically-actuated. The control can include a valve.
[0020] The control can adjust a cracking pressure of a flush valve
of the flusher. The control can adjust an effective volume of a
flush cavity of the flusher. The control can adjust the effective
volume by selectively inflating or deflating an inflatable member
disposed within the flush cavity. The control can adjust the
effective volume by moving at least a portion of a sidewall of the
flush cavity. The control can adjust the effective volume by
selectively advancing or retracting a movable member into or out of
the flush cavity. The catheter can include a plurality of auxiliary
flow ports, each having a progressively higher burst requirement.
The catheter can include a plurality of auxiliary flow ports, each
covered by membranes having progressively higher thicknesses. The
control can include a compliant feature movable between a collapsed
state and an expanded state. The compliant feature can include a
passive flow path therethrough. The compliant feature can be in
fluid communication with a flush emitted by the flusher, and the
compliant feature can move to the expanded state to absorb at least
a portion of the flush when in the restricted mode. The control can
include at least one valve that isolates the compliant feature from
the flush emitted by the flusher when in the unrestricted mode and
that places the compliant feature in fluid communication with the
flush when in the restricted mode. The control can be actuated to
progressively access a sequence of auxiliary flow ports through the
catheter. The control can be actuated to access the next in a
series of auxiliary flow ports of the catheter.
[0021] In some embodiments, a flusher can include an outer housing;
a passive flow path that extends between an upstream port and a
downstream port; a flush dome configured to be pressed to expel
fluid therefrom to flush fluid through at least one of the upstream
port and the downstream port; a flush valve configured to control
the pressure at which fluid is expelled from the flush dome; and a
shunt valve configured to regulate flow through the passive flow
path to control a patient's ventricle pressure; wherein the shunt
valve and the flush valve are disposed within the housing of the
flusher.
[0022] In some embodiments, a method can include actuating a
control of a flusher implanted in a patient to progressively access
a sequence of auxiliary flow ports through a ventricular catheter
in fluid communication with the flusher.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The invention will be more fully understood from the
following detailed description taken in conjunction with the
accompanying drawings, in which:
[0024] FIG. 1 is a schematic view of a shunt system implanted in a
patient;
[0025] FIG. 2A is a perspective view of a flusher;
[0026] FIG. 2B is a top view of the flusher of FIG. 2A;
[0027] FIG. 2C is an exploded perspective view of the flusher of
FIG. 2A;
[0028] FIG. 2D is another exploded perspective view of the flusher
of FIG. 2A;
[0029] FIG. 2E is another exploded perspective view of the flusher
of FIG. 2A;
[0030] FIG. 2F is a side view of the flusher of FIG. 2A;
[0031] FIG. 2G is another side view of the flusher of FIG. 2A;
[0032] FIG. 2H is another side view of the flusher of FIG. 2A;
[0033] FIG. 2I is a sectional top view of the flusher of FIG.
2A;
[0034] FIG. 2J is a sectional bottom view of the flusher of FIG.
2A;
[0035] FIG. 3A is a perspective view of a flusher;
[0036] FIG. 3B is an exploded perspective view of the flusher of
FIG. 3A;
[0037] FIG. 3C is a longitudinal sectional view of the flusher of
FIG. 3A;
[0038] FIG. 3D is a lateral sectional view of the flusher of FIG.
3A;
[0039] FIG. 3E is a perspective view of a valve cartridge of the
flusher of FIG. 3A;
[0040] FIG. 3F is a top view of the flusher of FIG. 3A;
[0041] FIG. 3G is a bottom view of the flusher of FIG. 3A with a
base plate removed;
[0042] FIG. 4A is a sectional view of a catheter;
[0043] FIG. 4B is an exploded view of the catheter of FIG. 4A;
[0044] FIG. 4C is a perspective view of an implanted catheter of
FIG. 4A with obstructions blocking primary inlet ports of the
catheter;
[0045] FIG. 4D is a perspective view of the catheter of FIG. 4C
with the obstructions cleared by a flushing operation;
[0046] FIG. 4E is a perspective view of the catheter of FIG. 4C
with an auxiliary inlet port of the catheter having been opened by
a flushing operation;
[0047] FIG. 5 is a schematic top view of a flusher;
[0048] FIG. 6 is a partially-exploded perspective view of a
flusher;
[0049] FIG. 7 is a top view of a flusher;
[0050] FIG. 8 is a schematic sectional top view of a flusher;
[0051] FIG. 9 is a sectional side view of a flusher;
[0052] FIG. 10 is a schematic top view of a flusher;
[0053] FIG. 11A is a schematic sectional top view of a flusher;
[0054] FIG. 11B is a schematic view of a slit valve that opens when
pressed;
[0055] FIG. 11C is a schematic view of a slit valve that closes
when pressed;
[0056] FIG. 12A is a schematic sectional top view of a flusher;
[0057] FIG. 12B is a schematic sectional side view of the flusher
of FIG. 12A;
[0058] FIG. 13 is a schematic sectional top view of a flusher;
[0059] FIG. 14A is a schematic top view of a shunt system;
[0060] FIG. 14B is a schematic top view of a flusher;
[0061] FIG. 15A is a schematic sectional top view of a flusher;
[0062] FIG. 15B is a side view of the flusher of FIG. 15A;
[0063] FIG. 15C is a schematic sectional top view of a flusher;
[0064] FIG. 16A is a schematic sectional top view of a flusher;
[0065] FIG. 16B is a schematic sectional top view of a flusher;
[0066] FIG. 16C is a schematic sectional side view of a
flusher;
[0067] FIG. 16D is a schematic view of a valve;
[0068] FIG. 17A is a side view of a catheter having a closed
auxiliary flow port;
[0069] FIG. 17B is a side view of the catheter of FIG. 17A with an
open auxiliary flow port;
[0070] FIG. 18A is a side view of a flusher;
[0071] FIG. 18B is a perspective view of the flusher of FIG. 18A
with a flush device;
[0072] FIG. 19 is a sectional side view of a catheter;
[0073] FIG. 20 is a sectional side view of a catheter;
[0074] FIG. 21 is a sectional side view of a catheter;
[0075] FIG. 22 is a sectional side view of a catheter;
[0076] FIG. 23 is a schematic perspective view of a shunt system
and a syringe;
[0077] FIG. 24 is a schematic sectional side view of a shunt
system;
[0078] FIG. 25 is a schematic sectional top view of a shunt
system;
[0079] FIG. 26 is a schematic sectional side view of a shunt
system;
[0080] FIG. 27A is a perspective view of a catheter;
[0081] FIG. 27B is a perspective view of a catheter;
[0082] FIG. 28A is a perspective view of a catheter;
[0083] FIG. 28B is a sectional side view of the catheter of FIG.
28A and an adjustment mechanism;
[0084] FIG. 29 is a perspective view of a catheter;
[0085] FIG. 30 is a sectional perspective view of a catheter;
[0086] FIG. 31 is a schematic sectional top view of a flusher;
[0087] FIG. 32 is a sectional side view of catheter;
[0088] FIG. 33 is a sectional side view of a catheter;
[0089] FIG. 34A is a schematic top view of a flusher;
[0090] FIG. 34B is a sectional side view of a compliant member of
the flusher of FIG. 34A, shown in a collapsed state;
[0091] FIG. 34C is a sectional side view of the compliant member of
FIG. 34B, shown in an expanded state;
[0092] FIG. 35 is a schematic top view of a flusher;
[0093] FIG. 36 is a sectional side view of an adjustable-volume
flusher;
[0094] FIG. 37 is a sectional side view of another
adjustable-volume flusher; and
[0095] FIG. 38 is a sectional side view of another
adjustable-volume flusher.
DETAILED DESCRIPTION
[0096] Systems and methods for flushing shunt systems are disclosed
herein. In some embodiments, a flusher includes a pinch tube that
extends over a flush dome such that a user can simultaneously close
the pinch tube and actuate the flush dome with a single motion.
Flushing and refill valves of the system can be disposed in a
cartridge that is laterally-offset from the flush dome,
advantageously reducing the height profile of the flusher. Flushers
with integrated shunt valves are also disclosed, as are shunt
systems with restricted and unrestricted modes for selectively
limiting the instances in which a user can open an auxiliary flow
path through the system.
[0097] Certain exemplary embodiments will now be described to
provide an overall understanding of the principles of the
structure, function, manufacture, and use of the methods, systems,
and devices disclosed herein. One or more examples of these
embodiments are illustrated in the accompanying drawings. Those
skilled in the art will understand that the methods, systems, and
devices specifically described herein and illustrated in the
accompanying drawings are non-limiting exemplary embodiments. The
features illustrated or described in connection with one exemplary
embodiment may be combined with the features of other
embodiments.
[0098] FIG. 1 illustrates an exemplary embodiment of a shunt system
100. The system generally includes a ventricular catheter 102, an
anchor 104, and a drain catheter 106 with an inline valve 108. In
some embodiments, the shunt system 100 can be used to treat
hydrocephalus by implanting the ventricular catheter 102 such that
a distal end of the catheter is disposed within a brain ventricle
110 of a patient 112. The anchor 104 can be mounted to the
patient's skull, beneath the skin surface, and the drain catheter
106 can be implanted such that the proximal end of the drain
catheter is disposed within a drain site, such as the abdominal
cavity. In some embodiments, the anchor 104 can be or can include a
Rickham-style reservoir. The valve 108 can be configured to
regulate the flow of fluid from the ventricle 110 to the drain
site. For example, when fluid pressure in the ventricle exceeds the
opening pressure of the valve 108, the valve can be configured to
open to allow excess fluid to drain out of the ventricle 110. When
the fluid pressure drops to an acceptable level, the valve 108 can
be configured to close, thereby stopping further draining of
fluid.
[0099] It will be appreciated that the arrangement and features of
the system 100 shown in FIG. 1 are merely exemplary, and that
several other variations are possible. For example, the valve 108
can be disposed distal to the anchor 104 instead of proximal
thereto as shown. In other embodiments, the valve 108 can be
integral to the anchor 104 or the anchor can be omitted
altogether.
[0100] The shunt system 100 can include any of a variety of
catheters, including single lumen catheters, multi-lumen catheters,
and split-tip catheters. Any of a variety of well-known valves 108
can be used, including those of the type described in U.S. Pat. No.
3,886,948, issued on Jun. 3, 1975 and entitled "VENTRICULAR SHUNT
HAVING A VARIABLE PRESSURE VALVE," the entire contents of which are
incorporated herein by reference.
[0101] In use, the shunt system 100 can be used to transfer fluid
from one location to another location. When used in a patient's
body, the shunt system 100 can be used to treat any of a variety of
diseases, conditions, or ailments. Further details on shunt systems
and related methods, including catheters and other features that
can be used with the systems described herein, can be found in U.S.
Pat. No. 9,433,764, issued on Sep. 6, 2016 and entitled "SYSTEMS
AND METHODS FOR SHUNTING FLUID," the entire contents of which are
incorporated herein by reference.
[0102] In some embodiments, the shunt system 100 can include a
flusher for clearing obstructions from the shunt system or for
opening auxiliary fluid paths through the shunt system (e.g.,
auxiliary fluid ports in the ventricular catheter). The flusher can
be disposed between the ventricular catheter 102 and the anchor
104, between the anchor 104 and the valve 108, or between the valve
108 and the drain catheter 106. The flusher can also be formed
integrally with any of the ventricular catheter 102, the anchor
104, the valve 108, and the drain catheter 106.
[0103] FIGS. 2A-2J illustrate an exemplary flusher 200 that can be
used with a shunt system (e.g., with the shunt system 100 described
above). The flusher 200 generally includes an outer shell or body
202 that defines a flush dome 204. The bottom surface of the body
202 is closed by a base plate 206 to which the body is sealed. A
flush valve assembly 208 and a refill valve assembly 210 are
disposed within a cartridge 214 coupled to the body 202, and a
pinch tube 212 or other collapsible fluid pathway extends over the
top of the flush dome 204. The cartridge is defined by upper and
lower housings 214A, 214B sealed to one another that define an
inner chamber 228 having an upper portion 228A and a lower portion
228B.
[0104] The valve cartridge 214 includes an upstream port 220
configured to be coupled to or placed in fluid communication with a
ventricular catheter, a flush port 222 configured to be placed in
fluid communication with the flush dome 204, and a passive flow
port 224 configured to be placed in fluid communication with the
pinch tube 212. The upstream port 220 and the passive flow port 224
are in fluid communication with the lower chamber 228B. The flush
port 222 is in fluid communication with the upper chamber 228A. The
ports 220, 222, 224 can be defined by barb-type fittings that
extend radially outward from the valve cartridge 214. The barbed
fittings can advantageously facilitate coupling of the cartridge
214 with the body 202 (in the case of the flush port 222), with the
pinch tube 212 (in the case of the passive flow port 224), or with
a ventricular catheter or other shunt system component (in the case
of the upstream port 220). High interference barbed fittings can be
used to allow high pressure operation without leakage, which allows
the flushing pressure to be delivered only to the flush valve and
facilitates more precise and repeatable opening pressure
thresholds. In some embodiments, the barbed fittings can be
configured to withstand up to 120 psi.
[0105] The flush valve assembly 208 includes a valve body 216 and
an adjustment disc 218. The valve body 216 can be an umbrella-type
valve, a Belleville-type valve, or the like. The valve body 216 is
sandwiched between the adjustment disc 218 and a dividing wall 226
that separates the upper and lower chambers 228A, 228B and in an
interference fit such that the valve body is compressed. The valve
body 216 defines a substantially concave upper surface that forms a
fluid-tight seal with the dividing wall 226 to seal off the flush
port 222 from the upstream port 220 and the passive flow port 224
during normal operation. When sufficient pressure is applied to the
upper surface of the valve body 216, the valve body deforms away
from the dividing wall 226 to allow fluid communication between the
flush port 222 and the upstream port 220 and between the flush port
and the passive flow port 224.
[0106] The threshold pressure at which the valve body 216 opens can
be infinitely adjusted by adjusting the pressure exerted on the
valve body by the adjustment disc 218. In the illustrated
embodiment, the adjustment disc 218 is threadably mounted in the
cartridge 214 such that rotating the disc in a first direction
increases the compression of the valve body 216 to increase the
threshold pressure, and such that rotating the disc in a second,
opposite direction decreases the compression of the valve body to
decrease the threshold pressure. It will be appreciated that other
means of adjusting the compression of the valve body 216 can be
used instead or in addition. A driving interface 230 can be formed
in the bottom surface of the adjustment disc 218 to facilitate
rotation of the disc by a driving tool. In the illustrated
embodiment, the driving interface 230 comprises first and second
opposed cylindrical recesses configured to receive corresponding
first and second pins of a driving tool. The arrangement of the
recesses can allow rotation of the disc 218 to be easily visualized
and to be performed in a repeatable and controlled manner. The
adjustment disc 218 can be adjusted in-process and locked in a
desired position using an adhesive (e.g., medical grade
cyanoacrylate or the like). Locking the disc 218 in place, e.g., by
freezing the threads using an adhesive, can advantageously allow
for the threshold pressure of the valve to be securely maintained
at the desired level.
[0107] When the valve body 216 is sealed against the dividing wall
226, fluid can flow from the upstream port 220, into the lower
portion 228B of the chamber 228, and around the outside of the
closed valve body. Fluid can also flow from the upstream port 220
into the passive flow port 224.
[0108] The refill valve assembly 210 includes a refill valve 236
and a refill plate 238. The refill plate 238 is defined by a
portion of the dividing wall 226 of the cartridge 214. The lower
part 228B of the cavity 228 extends beneath the refill plate 238
and is closed by a cover 240. The portion of the cavity 228B formed
below the refill plate 238 is in fluid communication with the
portion of the cavity 228B formed below the flush valve 216 via a
recess 244 formed in the dividing wall 226. The refill valve 236 is
operable to selectively place the lower cavity 228B in fluid
communication with the upper cavity 228A and, by extension, with
the interior of the flush dome 204, for example to refill the flush
dome after a flushing operation is performed. In the illustrated
embodiment, the refill valve 236 is an umbrella valve that includes
a valve stem and a valve head. The stem is mounted within a valve
guide formed in the refill plate 238. A plurality of openings 242
are formed in the plate 238 around the circumference of the valve
guide. When the refill valve 236 is closed, the valve head covers
the plurality of openings 242 and prevents fluid communication
between the lower cavity 228B and the upper cavity 228A. When the
refill valve 236 is opened, the valve head is lifted off of the
openings 242 such that fluid can flow from the lower cavity 228B to
the upper cavity 228A and into the flush dome 204.
[0109] As shown, the cartridge 214, including the refill valve 236
and the flush valve 216, is laterally offset from the flush dome
204, which can advantageously reduce the height profile of the
device 200 as compared with designs in which one or both valves are
vertically-aligned with the flush dome.
[0110] As shown in FIGS. 2D-2E, the geometry of the various
components of the flusher 200 can allow one or more (and in some
embodiments, all) of said components to be formed using a
straightforward molding process, advantageously reducing the
manufacturing cost and complexity of the flusher. In some
embodiments, the body 202, base plate 206, and pinch tube 212 are
molded from silicone and bonded to one another using silicone RTV
or other adhesive. These components can include a polyester
reinforcing mesh. In some embodiments, the cartridge 214 and the
barbed fittings can be formed from a polymer such as PEEK.
[0111] The pinch tube 212 can be configured to provide a valve-less
means of closing off the drain side of the shunt system during a
flush operation. The pinch tube 212 extends out of the valve
cartridge 214, across the top of the flush dome 204, and into a
housing that defines a downstream port 248 configured to be coupled
to or placed in fluid communication with a drain catheter, shunt
valve, or other downstream device. A drain tube, e.g., of the type
shown in FIG. 3B as element 350, can be bonded or otherwise
attached or coupled to the downstream port 248. The drain tube
and/or the downstream port 248 can be compatible with standard
barbs, downstream attachments, valves, drainage catheters, and the
like. The pinch tube 212 can be positioned such that it will
naturally be compressed by a user when the user actuates the flush
dome 204. The flusher 200 thus allows a single user motion, applied
at a single contiguous contact area, to both seal off the drain
side of the system and actuate the flush dome. In some embodiments,
the pinch tube 212 can be more easily deformable than the flush
dome 204 to increase the likelihood that the pinch tube is closed
off when a flushing operation is performed. For example, the pinch
tube 212 can be formed from a material having a lower durometer
than the material used to form the flush dome 204. In an exemplary
embodiment, the pinch tube 212 is formed from 30 durometer silicone
while the flush dome 204 is formed from 70 durometer silicone.
Closing off the pinch tube 212 prior to deflecting or actuating the
flush dome 204 can advantageously maximize the flush volume and/or
make the flush volume more consistent. The pinch tube 212 can be a
molded component that defines only a portion of a fluid lumen. The
remaining portion of the fluid lumen can be defined by the upper
surface of the flush dome 204. For example, as shown, the flush
dome 204 includes a trough 250 that, together with the pinch tube
212, defines a closed fluid lumen extending between the passive
flow port 224 and the downstream port 248.
[0112] The flusher 200 can be operable in a passive flow mode, a
flushing mode, and a refill mode.
[0113] During the passive flow mode of operation, the flush valve
216 and the refill valve 236 are both closed. Fluid from a
ventricular catheter flows into the valve cartridge 214 via the
upstream port 220. The fluid flows into the passive flow port 224,
through the pinch tube 212, out of the flusher 200 through the
downstream port 248, and then into a shunt valve, drain catheter,
or other downstream component of the shunt system. Fluid also flows
around the closed valve body 216 and fills the lower portion 228B
of the chamber 228.
[0114] A user can initiate a flushing operation by applying
pressure to the top of the flush dome 204 (e.g., by exerting
downward finger pressure on the dome through a patient's skin), to
collapse or compress the dome. During the flushing mode of
operation, the pinch tube 212 collapses under the pressure being
applied by the user to cut off fluid communication to the
downstream components of the shunt system. As the flush dome 204 is
depressed, the pressure in the flush dome increases, holding the
refill valve 236 in the closed position. The pressure in the flush
dome 204 increases until the threshold pressure of the flush valve
216 is reached, at which point the flush valve opens releasing a
cough or burst of fluid into the lower chamber 228B. The collapsed
pinch tube 212 prevents the burst of fluid from flowing through the
passive flow port 224, and therefore the burst of fluid instead
flows through the upstream port 220. This upstream "cough" or flush
of fluid can be effective to clear obstructions from a ventricular
catheter or other upstream component of the shunt system, or to
open auxiliary flow paths in a ventricular catheter. The terms
"cough" and "pulse" are used interchangeably herein to refer to the
burst of fluid emitted by the flusher. The cough or pulse can be of
a compressible fluid or substance or an incompressible fluid or
substance. Once the burst of fluid is released, the flush valve 216
returns to the closed position.
[0115] When a flushing operation is completed and the flush dome
204 is released, the pinch tube 212 opens to reestablish flow to
the downstream port 248 and the flush dome gradually returns to its
raised position. During this refill mode of operation, the flush
valve 216 is closed. Expansion of the flush dome 204 causes the
pressure in the flush dome to drop below the pressure in the lower
chamber 228B, which creates a pressure differential that causes the
refill valve 236 to open. Fluid in the lower chamber 228B can then
flow through the openings 242 formed in the refill plate 238 to
refill the flush dome 204. The cross-sectional area of the openings
242 can be made relatively small to limit the rate at which the
flush dome 204 is refilled and therefore the rate at which the
flush dome expands. This can advantageously prevent debris flushed
from the shunt system during the flushing operation from being
sucked back in as the flush dome 204 expands. Once the flush dome
204 is refilled, the flusher 200 returns to the passive flow mode
of operation.
[0116] The flusher 200 thus facilitates generation and application
of a high pressure cough of fluid which flushes the ventricle side
of the shunt system only. The pinch tube 212 prevents the cough of
fluid from travelling through the drain side of the shunt system.
In other embodiments, however, the flusher 200 can be configured to
flush the drain side of the system instead or in addition.
[0117] FIGS. 3A-3G illustrate an exemplary embodiment of a flusher
300. The flusher 300 generally includes an outer shell or body 302
that defines a flush dome 304. The bottom surface of the body 302
is closed by a base plate 306 to which the body is sealed. A flush
valve assembly 308 and a refill valve assembly 310 are disposed
within the body 302, and a pinch tube 312 extends over the top of
the flush dome 304.
[0118] The flush valve assembly 308 includes a valve cartridge 314,
a valve body 316, and an adjustment disc 318. The valve cartridge
314 includes an upstream port 320 configured to be coupled to or
placed in fluid communication with a ventricular catheter, a flush
port 322 configured to be placed in fluid communication with the
flush dome 304, and a passive flow port 324 configured to be placed
in fluid communication with a passive flow lumen 326 defined by the
body 302. Each of the ports 320, 322, 324 are in fluid
communication with an interior chamber defined 328 by the valve
cartridge 314. The upstream port 320 and/or the flush port 322 can
be defined by male barbed fittings that extend radially outward
from the valve cartridge 314. The barbed fittings can
advantageously facilitate coupling of the flush valve assembly 308
with the body 302 (in the case of the flush port 322) or with a
ventricular catheter or other shunt system component (in the case
of the upstream port 320). The passive flow port 324 can be defined
by an opening formed in a sidewall of the valve cartridge 314. The
valve cartridge 314 and the barbed fittings can be formed as
monolithic, one-piece component which can advantageously provide a
high strength unit capable of withstanding high operating pressures
and lateral stress on the upstream port fitting 320. High
interference barbed fittings can be used to allow high pressure
operation without leakage, which allows the flushing pressure to be
delivered only to the flush valve and facilitates more precise and
repeatable opening pressure thresholds. In some embodiments, the
barbed fittings can be configured to withstand up to 120 psi.
[0119] The valve body 316 can be an umbrella-type valve, a
Belleville-type valve, or the like. The valve body 316 is
sandwiched between the upper wall of the chamber 328 and the
adjustment disc 318 in an interference fit such that the valve body
is compressed. The valve body 316 defines a substantially concave
upper surface that forms a fluid-tight seal with the upper wall of
the chamber 328 to seal off the flush port 322 from the upstream
port 320 and the passive flow port 324 during normal operation.
When sufficient pressure is applied to the upper surface of the
valve body 316, the valve body deforms away from the upper wall of
the chamber 328 to allow fluid communication between the flush port
322 and the upstream port 320 and between the flush port and the
passive flow port 324. The threshold pressure at which the valve
body 316 opens can be infinitely adjusted by adjusting the pressure
exerted on the valve body by the adjustment disc 318. In the
illustrated embodiment, the adjustment disc 318 is threadably
mounted in the cartridge 314 such that rotating the disc in a first
direction increases the compression of the valve body 316 to
increase the threshold pressure, and such that rotating the disc in
a second, opposite direction decreases the compression of the valve
body to decrease the threshold pressure. It will be appreciated
that other means of adjusting the compression of the valve body 316
can be used instead or in addition. A driving interface 330 can be
formed in the bottom surface of the adjustment disc 318 to
facilitate rotation of the disc by a driving tool. In the
illustrated embodiment, the driving interface 330 comprises first
and second opposed cylindrical recesses configured to receive
corresponding first and second pins of a driving tool. The
arrangement of the recesses can allow rotation of the disc 318 to
be easily visualized and to be performed in a repeatable and
controlled manner. The adjustment disc 318 can be adjusted
in-process and locked in a desired position using an adhesive
(e.g., medical grade cyanoacrylate or the like). Locking the disc
318 in place, e.g., by freezing the threads using an adhesive, can
advantageously allow for the threshold pressure of the valve to be
securely maintained at the desired level.
[0120] When the valve body 316 is sealed against the upper wall of
the chamber 328, fluid can flow from the upstream port 320, into
the chamber, around the outside of the closed valve body, and into
the passive flow port 324.
[0121] The flush valve assembly 308 can be positioned within a
cavity 332 defined in the body 302 of the flusher 300 such that the
upstream port 320 protrudes through a sidewall of the body and such
that the flush port 322 extends into a passage 334 that connects
the cavity to the flush dome 304. When the flush valve assembly 308
is disposed in the body 302, the passive flow port 324 is aligned
with the passive flow channel 326 defined in the body.
[0122] The refill valve assembly 310 includes a refill valve 336
and a refill plate 338. The refill plate 338 is mounted in the body
302 beneath the flush dome 304. A passive flow channel 340 extends
through the refill plate 338 and is in fluid communication with the
passive flow channel 326 of the body 302 at one end and the pinch
tube 312 at the other end. The refill valve 336 is operable to
selectively place the passive flow channel 340 in fluid
communication with the interior of the flush dome 304, for example
to refill the flush dome after a flushing operation is performed.
In the illustrated embodiment, the refill valve 336 is an umbrella
valve that includes a valve stem and a valve head. The stem is
mounted within a valve guide formed in the refill plate 338. A
plurality of openings 342 are formed in the plate 338 around the
circumference of the valve guide. When the refill valve 336 is
closed, the valve head covers the plurality of openings 342 and
prevents fluid communication between the passive flow channel 340
and the flush dome 304. When the refill valve 336 is opened, the
valve head is lifted off of the openings 342 such that fluid can
flow between the passive flow channel 340 and the flush dome
304.
[0123] As perhaps best shown in FIG. 3C, the refill valve 336 is
disposed beneath the flush dome 304 and oriented such that the axis
A1 along which the valve opens and closes is substantially parallel
to the axis A2 along which the flush dome is actuated. In other
words, when an actuation force is applied to the flush dome 304
during a flushing operation, the primary component of the actuation
force acts in the same direction as the valve closing direction.
Also, the stacked nature of the refill valve 336 and flush dome 304
allows pressure in the flush dome to act directly on the refill
valve, helping ensure that the refill valve is closed when the
flush dome is actuated. The stacked arrangement also reduces the
overall length and profile of the flusher 300.
[0124] The refill plate 338 can be rigid, semi-rigid, or flexible.
The refill plate 338 can mechanically interlock with the body 302
to provide a robust connection capable of withstanding high
operating pressures. As shown, the refill plate 338 can be
disc-shaped and can include a sidewall that extends about a
circumference of the plate and protrudes radially-outward and
axially upward to define a lip 344 that is received within a
corresponding annular recess or undercut 346 formed in the body
302. The body 302 can be formed from a flexible material to allow
the body to be stretched over the lip 344 of the refill plate 338
during assembly. In some embodiments, the body 302 is molded from
silicone and bonded to the refill plate 338 using silicone RTV or
other adhesive. The base plate 306 can likewise be bonded to the
body 302 and/or to the refill plate 338 using silicone RTV or the
like. The base plate 306 can be formed from silicone and can
include a polyester reinforcing mesh.
[0125] The pinch tube 312 can be configured to provide a valve-less
means of closing off the drain side of the shunt system during a
flush operation. The pinch tube 312 extends out of the body 302,
across the top of the flush dome 304, and into a coupling where it
is placed in fluid communication with a downstream port 348
configured to be coupled to or placed in fluid communication with a
drain catheter, shunt valve, or other downstream device (e.g., via
a drain tube 350 as shown). The pinch tube 312 can be positioned
such that it will naturally be compressed by a user when the user
actuates the flush dome 304. The flusher 300 thus allows a single
user motion, applied at a single contiguous contact area, to both
seal off the drain side of the system and actuate the flush dome.
In some embodiments, the pinch tube 312 can be more easily
deformable than the flush dome 304 to increase the likelihood that
the pinch tube is closed off when a flushing operation is
performed. For example, the pinch tube 312 can be formed from a
material having a lower durometer than the material used to form
the flush dome 304. In an exemplary embodiment, the pinch tube 312
is formed from 30 durometer silicone while the flush dome 304 is
formed from 70 durometer silicone.
[0126] As shown in FIGS. 3F and 3G, the flusher 300 employs a
substantially T-shaped configuration in which the longitudinal axis
of the flusher body 302 extends perpendicular to the longitudinal
axis of the upstream port 320 and the longitudinal axis of the
drain tube 350. This can advantageously allow the flusher 300 to be
used with existing shunt systems without increasing the distance
between the anchor and the shunt valve. The T-configuration can
thus reduce or eliminate the need to add length to the overall
shunt system, and allows the flusher 300 to be positioned more
proximate to an incision over the burr hole that is typically used
when implanting shunt systems.
[0127] The flusher 300 can be operable in a passive flow mode, a
flushing mode, and a refill mode.
[0128] During the passive flow mode of operation, the flush valve
316 and the refill valve 336 are both closed. Fluid from a
ventricular catheter flows into the valve cartridge 314 via the
upstream port 320. The fluid flows around the closed valve body 316
and into the passive flow port 324 of the valve cartridge 314. From
there, the fluid flows through the passive flow channel 326 of the
body 302 and through the passive flow channel 340 of the refill
plate 338, past the closed refill valve 336. The fluid then flows
through the pinch tube 312, into the drain tube 350, and then into
a shunt valve, drain catheter, or other downstream component of the
shunt system.
[0129] A user can initiate a flushing operation by applying
pressure to the top of the flush dome 304 (e.g., by exerting
downward finger pressure on the dome through a patient's skin), to
collapse or compress the dome. During the flushing mode of
operation, the pinch tube 312 collapses under the pressure being
applied by the user to cut off fluid communication to the drain
tube 350 and the downstream components of the shunt system. As the
flush dome 304 is depressed, the pressure in the flush dome
increases, holding the refill valve 336 in the closed position. The
pressure in the flush dome 304 increases until the threshold
pressure of the flush valve 316 is reached, at which point the
flush valve opens releasing a cough or burst of fluid into the
valve cartridge 314. The collapsed pinch tube 312 prevents the
burst of fluid from flowing through the passive flow channels 326,
340, and therefore the burst of fluid instead flows through the
upstream port 320. This upstream "cough" or flush of fluid can be
effective to clear obstructions from a ventricular catheter or
other upstream component of the shunt system, or to open auxiliary
flow paths as described further below. Once the burst of fluid is
released, the flush valve 316 returns to the closed position.
[0130] When a flushing operation is completed and the flush dome
304 is released, the pinch tube 312 opens to reestablish flow to
the downstream port 348 and the flush dome gradually returns to its
raised position. During this refill mode of operation, the flush
valve 316 is closed. Expansion of the flush dome 304 causes the
pressure in the flush dome to drop below the pressure in the
passive flow channel 340, which creates a pressure differential
that causes the refill valve 336 to open. Fluid flowing through the
passive flow channel 340 can then flow through the openings 342
formed in the refill plate 338 to refill the flush dome 304. The
cross-sectional area of the openings 342 can be made relatively
small to limit the rate at which the flush dome 304 is refilled and
therefore the rate at which the flush dome expands. This can
advantageously prevent debris flushed from the shunt system during
the flushing operation from being sucked back in as the flush dome
304 expands. Once the flush dome 304 is refilled, the flusher 300
returns to the passive flow mode of operation.
[0131] The flusher 300 thus facilitates generation and application
of a high pressure cough of fluid which flushes the ventricle side
of the shunt system only. The pinch tube 312 prevents the cough of
fluid from travelling through the drain side of the shunt system.
In other embodiments, however, the flusher 300 can be configured to
flush the drain side of the system instead or in addition.
[0132] FIGS. 4A-4E illustrate an exemplary embodiment of a catheter
400 that can be used with a shunt system (e.g., with the shunt
system 100 described above). The catheter 400 includes a plurality
of inlet holes formed at a distal tip end of the catheter
configured to be disposed within a patient's ventricle. While a
single-lumen, single-tip catheter is shown, it will be appreciated
that the catheter can be a multi-lumen catheter and/or a multi-tip
catheter. For example, the catheter can be a dual lumen catheter
with two independent lumens that extend the full length of the
catheter. By way of further example, the catheter can be a
split-tip catheter having first and second tips at the distal end
that merge into a single lumen that extends through the remainder
of the catheter.
[0133] The plurality of inlet holes includes one or more primary
holes 402 which form pathways through which fluid external to the
catheter 400 can enter an inner lumen of the catheter. The
plurality of inlet holes also includes one or more auxiliary holes
404 which are initially blocked such that fluid external to the
catheter 400 cannot pass through the auxiliary holes into an inner
lumen of the catheter. Rather, fluid can only pass through the
auxiliary holes 404 after they are forced open (e.g., by a flushing
operation of one of the flushers disclosed herein). The auxiliary
holes 404 are initially blocked by a membrane 406. In some
embodiments, the membrane 406 can be disposed over the exterior
surface of the catheter 400. The membrane 406 can be formed from a
variety of implantable and biocompatible materials, such as
silicone. The membrane 406 can be stretched across the openings 404
and attached to the catheter 400 under tension, such that
penetration of the membrane results in a tear in which opposed
sides of the tear move out of the way of the underlying hole. The
membrane 406 can be stretched over the auxiliary holes 404 in a
variety of directions or orientations, which can allow for the tear
produced when the membrane is ruptured to have some directionality
(i.e., to define an opening that faces in a particular direction).
The stretched membrane 406 can be attached to the catheter 400 in
various ways. For example, the membrane 406 can be thermally welded
to the catheter 400 using a heat punch, mechanically coupled to the
catheter using O-rings disposed around the membrane and the
catheter, or molded into or onto the catheter. In some embodiments,
a plurality of auxiliary holes can be provided, each having a
membrane stretched in a different direction. The thickness of the
membrane, the degree of tension applied to the membrane, and the
material from which the membrane is formed can be selected to
control the force required to tear the membrane. In some
embodiments, the membrane can be configured to burst at an opening
pressure of about 5 psi to about 15 psi. In some embodiments, the
membrane is formed from silicone and has a thickness of about 0.001
inches.
[0134] The catheter 400 can include a stiffening sleeve 401
disposed over the membrane. The stiffening sleeve 401 can include
an opening 403 that is aligned with the auxiliary hole 404, and can
be positioned in a recessed portion 405 of the catheter such that
the stiffening sleeve and the catheter define a continuous, smooth
outer surface. The stiffening sleeve 401 can advantageously prevent
the catheter 400 from bending or ballooning under the pressure of a
flushing cough while at the same time focusing the cough pressure
on the membrane 406. The catheter 400 can also include a bullet-tip
plug 409 that seals the terminal distal end of the catheter.
[0135] In some embodiments, the catheter 400 can be manufactured by
extruding a silicone tube to form a catheter main body 407 with the
desired inside and outside diameters. The tube can then be cut to
the desired length. The distal portion 411 of the catheter,
including the recess 405 for the stiffening sleeve 401, can then be
formed on one end of the tube using a silicone overmolding process.
Primary and auxiliary holes 402, 404 can be added to this distal
portion 411 later in a separate drilling step. Once the auxiliary
hole 404 is formed, a silicone membrane 406 can be molded over the
opening. Alternatively, the membrane 406 and the auxiliary hole 404
defined beneath the membrane 406 can be formed simultaneously by
molding them as one monolithic, continuous part formed from
silicone or other materials. In other words, the auxiliary hole 404
can be initially formed as a non-full-thickness or blind hole, with
the remaining thickness defining the membrane 406. The stiffening
sleeve 401 can be formed from a PEEK extrusion and a laser cutting
process can be used to form the window 403 in the stiffening
sleeve. The stiffening sleeve 401 can be positioned over the
membrane 406 and bonded in place using RTV silicone or the like.
The distal plug 409 can be molded as a separate silicone component
and then sealed to the distal end of the catheter using RTV
silicone or the like.
[0136] Any one or more components of the catheter 400 can be formed
from a radiopaque material or can have a radiopaque material
embedded or impregnated therein to facilitate visualization using
various imaging techniques. In some embodiments, barium sulfate or
other radiopaque materials can be molded into the distal portion
411 of the catheter, the main body 407 of the catheter, the
stiffening sleeve 401, the membrane 406, and/or the distal tip
409.
[0137] The catheter 400 can include various features for
facilitating a determination as to whether the membrane 406 has
been opened using CT, X-ray, or other imaging techniques. For
example, a thin ribbon of radiopaque material can be printed on the
membrane. When the membrane opens, radiographic images of the
implanted catheter can show the ribbon of material being torn away
or separated. The ribbon can be deposited or printed on the
membrane in an ultra-thin layer using nanotechnology. The ribbon
can extend longitudinally, laterally, diagonally, or in any other
direction or directions across the auxiliary opening, and can be
formed in a matrix or any other pattern.
[0138] In use, the catheter 400 is implanted in a patient with the
distal tip of the catheter disposed in the patient's ventricle.
Fluid enters the primary holes 402 of the catheter and flows
through the inner lumen of the catheter to a downstream portion of
the shunt system (e.g., a flusher, a valve, and/or a drain
catheter). When the primary holes 402 become clogged or obstructed
(e.g., as shown in FIG. 4C), or at any other time a user so
desires, a flusher can be actuated to deliver a pressurized cough
of fluid through the inner lumen of the catheter. The cough of
fluid can dislodge obstructions 408 from the clogged primary holes
402 (e.g., as shown in FIG. 4D) and/or cause the membrane 406
covering one or more auxiliary holes 404 to burst (e.g., as shown
in FIG. 4E). In other words, flushing the catheter can open the
auxiliary inlet ports 404 to provide a secondary fluid pathway into
the catheter, e.g., when the primary fluid pathway becomes clogged
or obstructed.
[0139] FIG. 5 illustrates an exemplary flusher 500 that can be used
with a shunt system (e.g., with the shunt system 100 described
above). As shown, the flusher 500 can include an upstream port 502
configured to be coupled to or placed in fluid communication with a
ventricular catheter and a downstream port 504 configured to be
coupled to or placed in fluid communication with a drain catheter
or other downstream device. The flusher 500 can include a flush
dome or reservoir 506 that can contain fluid and can be actuated to
flush a cough of fluid through the upstream port 502, the
downstream port 504, or both. The flusher 500 can include a flush
valve 508 that controls the release of the cough of fluid. The
flusher 500 can include a refill valve 510 that controls refilling
of the flush dome 506 after a flushing operation. The flusher 500
can include a shunt valve 512 that controls draining of fluid
through the shunt system, e.g., to control draining of fluid
between a brain ventricle and a drain site of a patient. The
flusher 500 can include a control 514 that can be used to
selectively activate or deactivate one or more functions of the
flusher. The components of the flusher 500 can be contained within
a housing 516.
[0140] While the illustrated flusher 500 includes a flush dome 506,
flush valve 508, refill valve 510, shunt valve 512, and control 514
all housed within a single housing 516, it will be appreciated that
one or more of said components can be formed in a separate housing
or structure, which can be directly assembled with the housing 516
or disposed remotely therefrom. In addition, it will be appreciated
that one or more of said components can be omitted altogether.
[0141] The illustrated flusher 500 includes an internal shunt valve
512. Integrating the shunt valve with the flusher can
advantageously reduce the number of implanted components, reduce
the invasiveness of using and installing the shunt system, reduce
the cost and complexity of the shunt system, or achieve other
advantages that will be appreciated from the description below. The
shunt valve 512 can be or can include the features of any of a
variety of known or commercially-available shunt valves, including
programmable shunt valves and non-invasively adjustable shunt
valves.
[0142] Incorporating a control 514 that can be used to selectively
activate or deactivate one or more functions of the flusher 500
into the system can provide various advantages.
[0143] In some embodiments, the control 514 can allow non-invasive
activation or deactivation of the flushing function. For example,
the control 514 can lock the flush valve 508 in a closed position
to disable all flushing through the system. This can be used, for
example, to limit use of the flusher to controlled environments or
to selected individuals. In one scenario, a patient could be
prevented from flushing the system while a clinician would be able
to actuate the control 514 to enable flushing.
[0144] In some embodiments, the control 514 can allow non-invasive
activation or deactivation of the auxiliary flow port function. For
example, the control 514 can limit the flushing pressure or volume
to an amount that is insufficient to open an auxiliary flow port in
a catheter of the system. As another example, the control 514 can
use mechanical or hydraulic means to isolate the auxiliary flow
port from the flushing pressure. This can be used, for example, to
ensure that the auxiliary flow port is only opened when
specifically intended, while still allowing flushing operations to
be performed in an effort to clear obstructions through the primary
flow ports of the catheter. In one scenario, a patient would be
free to perform flushing operations to clear debris from the
primary flow ports, but would be prevented by the control 514 from
performing a flushing operation to open the auxiliary flow port(s).
Rather, only a clinician or other individual capable of adjusting
the control 514 would be able to open the auxiliary flow ports.
[0145] In some embodiments, the catheter can include isolated first
and second fluid lumens, with the first fluid lumen being in
communication with a primary flow port and the second fluid lumen
being in fluid communication with an auxiliary flow port. The
control 514 can selectively switch which fluid lumen is placed in
fluid communication with the flush dome 506 to control whether a
flushing operation will clear a primary flow port or open an
auxiliary flow port.
[0146] In some embodiments, the control 514 can adjust the opening
pressure of the flush valve 508 to control the pressure and force
of the resulting cough of fluid. The control 514 can limit the
pressure to a value that is insufficient to open an auxiliary flow
port.
[0147] In some embodiments, the control 514 can limit the volume of
the flush, e.g., by controlling the refill valve 510 to limit
refill of the flush dome 506, or by moving a physical divider
within the flush dome 506, to control the volume of the resulting
cough of fluid. The control 514 can limit the volume to a value
that is insufficient to open an auxiliary flow port.
[0148] In some embodiments, the control 514 can facilitate a
flushing operation and/or allow non-invasive control of flushing
directionality. For example, the control 514 can close a downstream
valve to direct the flush through the upstream port 502 only, or
close an upstream valve to direct the flush through the downstream
port 504 only. This can allow pinch tubes and other structures for
blocking flow in the undesired direction to be omitted from the
flusher.
[0149] While the control 514 is shown as being formed integrally
with the flusher 500, it can alternatively or additionally be
formed as a separate component or be formed integrally with the
catheter or other component of a shunt system.
[0150] In the discussion that follows, a number of flushers,
catheters, and other devices are described that include an
integrated shunt valve and/or a control of the type described
above. The features illustrated or described in connection with one
exemplary device or embodiment may be combined with the features of
other devices or embodiments.
[0151] FIG. 6 illustrates an exemplary flusher 600. The flusher 600
is similar to the flusher 200 described above, except that it also
includes an integrated shunt valve 612 disposed in-line with the
passive flow port of the cartridge. The shunt valve 612 can be
non-invasively adjustable, e.g., magnetically-adjustable. The shunt
valve 612 can be an umbrella valve, a ball-and-spring valve, a
one-way pressure controlled diaphragm valve, etc. The shunt valve
612 can be a slit valve with a predicable opening pressure. The
shunt valve 612 can be incorporated into a portion of the cartridge
housing and can be provided as part of a kit with multiple modular
cartridge housing portions, each having a different shunt valve 612
opening pressure. A cartridge portion having the desired opening
pressure can be selected from the kit and assembled to the flusher
600 before use.
[0152] FIG. 7 illustrates an exemplary flusher 700. The flusher 700
is similar to the flusher 200 described above, except that it also
includes an integrated shunt valve 712 disposed in-line with the
drain port 704. The shunt valve 712 can be non-invasively
adjustable, e.g., magnetically-adjustable. The shunt valve 712 can
be an umbrella valve, a ball-and-spring valve, a one-way pressure
controlled diaphragm valve, etc. The shunt valve 712 can be a slit
valve with a predicable opening pressure. The shunt valve 712 can
be incorporated into a modular drain port and can be provided as
part of a kit with multiple modular drain ports, each having a
different shunt valve 712 opening pressure. A drain port having the
desired opening pressure can be selected from the kit and assembled
to the flusher 700 before use.
[0153] FIG. 8 illustrates an exemplary flusher 800 that includes an
upstream or ventricle port 802, a downstream or drain port 804, and
a first flush dome or reservoir 806A. The flusher 800 can include a
flush valve, a refill valve, a shunt valve, and/or a control of the
type described herein. The illustrated flusher 800 includes a shunt
valve 812 in-line with the drain port 804. The flusher 800 includes
a second flush dome 806B for flushing the drain side of the system,
disposed downstream from the shunt valve 812. Actuation of the
second flush dome 806B can urge a cough of fluid through the drain
side of the system. The shunt valve 812 can be a check valve to
prevent the flushing cough from traveling upstream. The second
flush dome 806B can act as a shunt tap. For example, the second
flush dome 806B can be penetrable by a needle to inject fluid into
the system or to withdraw fluid from the system. The second flush
dome 806B can include a rigid plate or shield to prevent
over-insertion of the shunt tap needle. In some embodiments, the
second flush dome 806B can instead be configured to flush the
upstream side of the system, but with a flush volume or flush
pressure less than that of the first flush dome 806A, such that
actuation of the second flush dome 806B does not open auxiliary
flow paths through the ventricular catheter. In some embodiments,
the direction of the flush generated by the second flush dome 806B
can be controlled by a setting, either upon implantation or with a
control switched from outside the patient.
[0154] FIG. 9 illustrates a portion of an exemplary flusher 900.
The flusher 900 is similar to the flusher 200 described above,
except that it also includes an integral shunt valve 912 disposed
adjacent to the flush valve 908. A magnetically-movable rotor 918
can be positioned below the flush valve 908. The rotor 918 can be
configured to rotate about a spindle 920 to adjust the preload on a
spring 922 supporting a ball-in-cone type valve 924. The rotor 918
can define a stepped or ramped surface having a progressively
increasing height about the circumference of the rotor.
Alternatively, or in addition, the rotor 918 can define a stepped
or ramped circumferential surface such that the radius of the rotor
changes about the circumference of the rotor. An external magnetic
field can be applied to the rotor 918 to turn the rotor and align a
specific portion of the rotor with the spring 922. Aligning a
taller or radially-larger portion of the rotor 918 with the spring
922 can compress the spring to increase the pressure on the ball
924 and increase the opening pressure of the shunt valve 912.
Aligning a shorter or radially-smaller portion of the rotor 918
with the spring 922 can relax the spring to decrease the pressure
on the ball 924 and decrease the opening pressure of the shunt
valve 912. The shunt valve 912 is disposed to control fluid flow
through the passive flow path of the flusher 900.
[0155] FIG. 10 illustrates an exemplary flusher 1000. The flusher
1000 is similar to the flusher 200 described above, except that the
pinch tube can serve as a shunt tap 1026. A needle guard 1028 can
be positioned between the pinch tube and the flush dome 1006 to
prevent the shunt tap needle from penetrating into the flush dome.
The needle guard 1028 can be formed by a rigid plate, e.g., formed
from a polymer such as PEEK or a metal such as titanium, stainless
steel, or cobalt chromium.
[0156] FIG. 11A illustrates an exemplary flusher 1100 that includes
an upstream or ventricle port 1102, a downstream or drain port
1104, and a flush dome or reservoir 1106A. The upstream port 1102
is a "Y-entry" port in which first and second fluid lumens 1102A,
1102B of the upstream port are coupled to the flush dome 1106A. The
first and second fluid lumens 1102A, 1102B can merge into a single
lumen in the housing of the flusher 1100 or in the ventricular
catheter.
[0157] A first valve 1130A controls fluid communication between the
first fluid lumen 1102A and the flush dome 1106A and is normally
open, but closes when the flush dome is pressed. A second valve
1130B controls fluid communication between the second fluid lumen
1102B and the flush dome 1106A and is normally closed, but opens
when the flush dome is pressed. A third valve 1130C controls fluid
communication between the flush dome 1106A and the downstream
portion of the flusher and is normally open but closes when the
flush dome is pressed. The downstream portion of the flusher 1100
can include a shunt tap dome 1106B and a shunt valve 1112.
[0158] In operation, when the flush dome 1106A is not pressed, the
first and third valves 1130A, 1130C are open and fluid flows from
the ventricle, through the first fluid lumen 1102A, through the
flush dome 1106A (refilling the flush dome if applicable), through
the shunt tap dome 1106B (refilling the shunt tap dome if
applicable), and against the shunt valve 1112 which selectively
opens to drain fluid through the drain port 1104 to control
pressure in the ventricle. When the flush dome 1106A is pressed,
the first and third valves 1130A, 1130C close and the second valve
1130B opens. Accordingly, a flushing cough of fluid flows out of
the flush dome 1106A, through the second valve 1130B, and through
the second fluid lumen 1102B to flush the upstream side of the
system. The closed off third valve 1130C prevents the flush from
flowing through the drain side of the system.
[0159] FIG. 11B illustrates an exemplary valve 1130 that can be
used for the second valve 1130B of the flusher 1100. The valve 1130
can be defined by a slit formed in a wall of compressible material.
In some embodiments, the wall can be formed from a biocompatible
elastomer such as silicone. The slit can have a resting state that
is closed as shown in the top part of FIG. 11B to prevent fluid
flow therethrough. The slit can have a major axis that is parallel
to a force applied to the wall when the flush dome 1106A is
pressed. The force can be effective to deform the wall to cause the
slit to open as shown in the bottom part of FIG. 11B to allow fluid
to flow therethrough. The illustrated valve 1130 is thus normally
closed, but opens when pressed.
[0160] FIG. 11C illustrates an exemplary valve 1130' that can be
used for the first and third valves 1130A, 1130C of the flusher
1100. The valve 1130' can be defined by a slit formed in a wall of
compressible material. In some embodiments, the wall can be formed
from a biocompatible elastomer such as silicone. The slit can have
a resting state that is open as shown in the top part of FIG. 11C
to allow fluid flow therethrough. The slit can have a major axis
that is perpendicular to a force applied to the wall when the flush
dome 1106A is pressed. The force can be effective to deform the
wall to cause the slit to close as shown in the bottom part of FIG.
11C to block fluid flow therethrough. The illustrated valve 1130'
is thus normally open, but closes when pressed.
[0161] FIGS. 12A-12B illustrate an exemplary flusher 1200 that
includes an upstream or ventricle port 1202, a downstream or drain
port 1204, a first retrograde flush dome or reservoir 1206A, and a
second antegrade flush dome or reservoir 1206B. Either of the flush
domes can also serve as a shunt tap. The upstream port 1202 is a
"Y-entry" port in which first and second fluid lumens 1202A, 1202B
of the upstream port are coupled to the first flush dome 1206A. The
first and second fluid lumens 1202A, 1202B can merge into a single
lumen in the housing of the flusher 1200 or in the ventricular
catheter. The downstream port 1204 is a "Y-exit" port in which
first and second fluid lumens 1204A, 1204B of the downstream port
are coupled to the second flush dome 1206B. The first and second
fluid lumens 1204A, 1204B can merge into a single lumen in the
housing of the flusher 1200 or in the drain catheter.
[0162] A first valve 1230A controls fluid communication between the
first fluid lumen 1202A and the first flush dome 1206A and is
normally open, but closes when the first flush dome is pressed. A
second valve 1230B controls fluid communication between the second
fluid lumen 1202B and the first flush dome 1206A and is normally
closed, but opens when the first flush dome is pressed. A third
valve 1230C controls fluid communication between the first flush
dome 1206A and the second flush dome 1206B and is normally open but
closes when the first flush dome or the second flush dome is
pressed. A fourth valve 1230D controls fluid communication between
the second flush dome 1206B and the first fluid lumen 1204A and is
normally closed but opens when the second flush dome is pressed. A
shunt valve 1212 is disposed in-line with the second fluid lumen
1204B.
[0163] In operation, when neither flush dome 1206A, 1206B is
pressed, the first and third valves 1230A, 1230C are open and fluid
flows from the ventricle, through the first fluid lumen 1202A,
through the first flush dome 1206A (refilling the dome if
applicable), through the second flush dome 1206B (refilling the
dome if applicable), and against the shunt valve 1212 which
selectively opens to drain fluid through the drain port 1204 to
control pressure in the ventricle. The fourth valve 1230D is closed
to prevent passive flow through the first fluid lumen 1204A of the
drain port 1204.
[0164] When the first flush dome 1206A is pressed, the first and
third valves 1230A, 1230C close and the second valve 1230B opens.
Accordingly, a flushing cough of fluid flows out of the first flush
dome 1206A, through the second valve 1230B, and through the second
fluid lumen 1202B of the upstream port 1202 to flush the upstream
side of the system. The closed off third valve 1230C prevents the
flush from flowing through the drain side of the system.
[0165] When the second flush dome 1206B is pressed, the third valve
1230C closes and the fourth valve 1230D opens. Accordingly, a
flushing cough of fluid flows out of the second flush dome 1206B,
through the fourth valve 1230D, and through the first fluid lumen
1204A of the downstream port 1204 to flush the downstream side of
the system. The fourth valve 1230D allows the fluid flush to bypass
the shunt valve 1212, which may or may not open during the flushing
operation. The closed off third valve 1230C prevents the flush from
flowing through the upstream side of the system.
[0166] The valves of the flusher 1200 can be slit valves of the
type described above of any of a variety of other valve types. In
some embodiments, the third valve 1230C can be omitted and the
flush domes 1206A, 1206B can be integrated into a single dome.
Accordingly, pressing the combined dome would flush both the
upstream and the downstream sides of the system.
[0167] FIG. 13 illustrates an exemplary flusher 1300 that includes
an upstream or ventricle port 1302, a downstream or drain port
1304, a flush dome or reservoir 1306A, and a shunt tap dome or
reservoir 1306B having a shunt valve 1312 therein. The shunt tap
dome 1306B can be pierceable and the flush dome 1306A can be
non-pierceable. The flush dome 1306A and the shunt tap dome 1306B
can be connected by a control valve 1314 configured to control
fluid communication therebetween. The valve 1314 can be normally
closed but can be configured to open when the flush dome 1306A is
pressed. A slit valve of the type described above or any of a
variety of other valve types can be used. In operation, when the
flush dome 1306A is not pressed, the control valve 1314 is closed
and fluid flows from the upstream port 1302 to the downstream port
1304, with the shunt valve 1312 controlling the flow to regulate
the patient's ventricle pressure. When the flush dome 1306A is
pressed, the control valve 1314 opens allowing a cough of fluid to
flush the upstream and downstream sides of the system.
[0168] A shunt tap dome or reservoir can be incorporated into any
of the shunt systems described herein. For example, as shown in
FIG. 14A, a Rickham-style reservoir or burr hole dome 1432 can be
placed in-line between the flusher/shunt valve 1400 and the
ventricular catheter 1401 and can be used for shunt tapping. As
shown in FIG. 14B, the shunt tap dome 1432' can be directly mated
to the flusher housing 1400' or can be formed integrally with the
flusher housing.
[0169] FIGS. 15A-15B illustrate an exemplary flusher 1500 that
includes an upstream or ventricle port 1502, a downstream or drain
port 1504, and a housing that includes a first flush dome or
reservoir 1506A and a second shunt tap dome or reservoir 1506B.
Either of the domes can serve as a shunt tap dome and can include a
needle guard of the type described above. As shown in FIG. 15B, the
ventricle port 1502 (and a ventricular catheter 1501 coupled
thereto) can be oriented perpendicular to the flusher housing and
to the drain port 1504. This can allow the flusher 1500 to be
positioned over a burr hole in the patient's skull and to provide a
simple 90-degree transition between the ventricular catheter 1501
descending down through the burr hole into the brain and the drain
catheter extending along the skull surface beneath the skin.
[0170] The drain port 1504 is connected to the second dome 1506B by
an adjustable shunt valve and/or occluder 1512. The occluder 1512
can be actuated, e.g., by manual finger pressure exerted thereon
through the skin of the patient or by increasing the pressure
threshold of the shunt valve to a very high setting, to cut off
fluid communication between the second dome 1506B and the drain
port 1504. When the occluder 1512 is in a resting state and no
force is applied thereto, the drain port 1504 is in fluid
communication with the second dome 1506B. Any of the shunt valves
described herein can be used for the shunt valve/occluder 1512.
[0171] The second dome 1506B is connected to the first dome 1506A
by a refill valve 1510. The refill valve 1510 allows one way flow
of fluid from the second dome 1506B to the first dome 1506A to
refill the first dome, e.g., after a flushing operation is
performed. Any of the refill valves disclosed herein can be used
for the refill valve 1510.
[0172] The first dome 1506A is in selective fluid communication
with the ventricle port 1502 via a flush valve 1508. Any of the
flush valves disclosed herein can be used for the flush valve 1508.
When no force is applied to the flush dome 1506A, the flush valve
1508 is closed to cut off fluid communication between the flush
dome 1506A and the ventricle port 1502. When the flush dome 1506A
is pressed and a threshold opening pressure is reached, the flush
valve 1508 opens to establish fluid communication between the flush
dome 1506A and the ventricle port 1502.
[0173] A control valve 1514 controls fluid communication between
the second dome 1506B and the ventricle port 1502. The control
valve 1514 can be remotely or non-invasively actuated. For example,
the control valve 1514 can be a magnetically-controlled valve.
[0174] The flusher 1500 can operate in a number of different
modes.
[0175] In a restricted operating mode, the control valve 1514 is
open and passive flow occurs when no force is applied to the domes
1506A, 1506B. In passive operation, fluid flows from the ventricle,
through the ventricle port 1502, around the flush valve 1508,
through the open control valve 1514, through the second dome 1506B
and against the shunt valve/occluder 1512, which controls
subsequent flow through the drain port 1504 to regulate ventricle
pressure. The passive flow refills the second dome 1506B (if
refilling is needed) and flows through the refill valve 1510 to
refill the first dome 1506A (if refilling is needed).
[0176] If the first flush dome 1506A is depressed in the restricted
operating mode, the flushing cough will follow the path of least
resistance, either clearing obstructions from the primary flow
ports of the ventricular catheter 1501 or flowing through the drain
port 1504. Typically, both of these paths provide less resistance
than required to open an auxiliary flow port of the ventricular
catheter 1501. Accordingly, in the restricted operating mode, a
user is prevented from opening the auxiliary flow port.
[0177] In an unrestricted operating mode, the control valve 1514 is
closed. With the control valve 1514 closed, the drain side of the
system is blocked and pressing the flush dome 1506A directs the
cough of fluid through the ventricle side of the system only.
Accordingly, the flush is effective to clear obstructions from a
primary flow port of the ventricular catheter, open an auxiliary
port of the ventricular catheter, or both. Thus, in the
unrestricted operating mode, a user is permitted to open the
auxiliary flow port.
[0178] When the control valve 1514 is closed, the second dome 1506B
and the occluder 1512 can be used to increase the intensity of the
flushing cough. By actuating the occluder 1512 to block flow
through the drain port 1504 and pressing the second dome 1506B, the
pressure in the first dome 1506A can be increased to pre-charge the
first dome 1506A. As a result, the initial pressure in the flush
dome 1506A is elevated and subsequently pressing the flush dome
1506A increases the pressure even more to generate a high intensity
cough of fluid. The user can thus apply a low level flush by
pressing the first dome 1506A without pressing the second dome
1506B or closing the occluder 1512. The user can apply a high level
flush by closing the occluder 1512 and pressing the second dome
1506B before pressing the first dome 1506A.
[0179] When the control valve 1514 is closed and a flushing
operating is performed, the closed control valve prevents the flush
dome 1506A from refilling from the ventricle side of the system.
The flush dome 1506A can thus remain empty after the flushing
operation. Typically, a user can discern that the flush dome 1506A
is empty by palpating the dome through the patient's skin, and
therefore this mode of operation can give the user confidence that
a flushing operation was performed when an empty dome is observed.
In some embodiments, subsequent flushing operations cannot be
performed until the control valve 1514 is opened to allow the dome
1506A to refill. This can help the user ensure that only a single
flushing operation is performed at a time, and make it easier to
keep track of the number of flushing operations that are
performed.
[0180] FIG. 15C illustrates a flusher 1500' that is similar to the
flusher 1500 described above except that it includes a pinch tube
1534 disposed over the first flush dome 1506A that provides a fluid
communication path between the ventricle port 1502 and the second
dome 1506B. The pinch tube 1534 can allow passive flow to occur
through the flusher even when the control valve 1514 is closed. The
pinch tube 1534 collapses to block the drain side of the system
when the first dome 1506A is depressed, such that a flushing
operation performed while the control valve 1514 is closed is still
effective to flow only through the ventricle side of the
system.
[0181] In some embodiments, a flusher can include a dual flush
function. The flusher can be configured to emit a first flush
having a pressure P1 and a second flush having a pressure P2 that
is greater than P1. Alternatively, or in addition, the first flush
can have a volume V1 and the second flush can have a volume V2 that
is greater than V1. The first flush can be sufficient to clear
debris from a primary flow port of a catheter, but insufficient to
open an auxiliary flow port of the catheter. The second flush can
be sufficient to open an auxiliary flow port through the catheter.
The system can include features to limit use of the second flush,
for example, to allow a patient to perform the first flush but to
limit use of the second flush to a clinician. In one example, the
first flush can have a volume of 0.25 mL and a pressure of 10 psi
and the second flush can have a volume of 0.5 mL and a pressure of
30 psi.
[0182] FIGS. 16A-16D illustrate a flusher with a dual flush
function. The flusher 1600 includes a first flush dome 1606A and a
second flush dome 1606B separated by a first control valve 1612A.
The flush domes 1606A, 1606B can be stacked vertically, e.g., as
shown in FIG. 16A, or can be positioned side-by-side, e.g., as
shown in FIG. 16B. The first flush dome 1606A can be connected to
the ventricle port 1602 by a second control valve 1612B. The second
flush dome 1606B can be connected to the ventricle port 1602 by a
flush valve 1608. The flusher 1600 can include a pinch tube as
shown to block the drain port 1604 when the flush domes 1606A,
1606B are pressed. The flusher 1600 can be configured such that
pressing on a top surface of the flusher at a single contiguous
contact area is effective to collapse the pinch tube and both flush
domes 1606A, 1606B.
[0183] The first and second control valves 1612A, 1612B can be
opened or closed non-invasively. FIG. 16D illustrates an exemplary
valve that includes a rotatable magnetic disc. Application of an
external magnetic field to the valve can rotate the disc to open or
close the valve. Various other non-invasively adjustable valves can
be used instead or in addition.
[0184] The flusher 1600 is operable in a restricted operating mode
in which the first control valve 1612A is closed and the second
control valve 1612B is open. In the restricted operating mode,
pressing the flusher 1600 collapses the first dome 1606A. Fluid in
the first flush dome 1606A escapes through the open second control
valve 1612B to the ventricle port 1602 without generating a high
pressure cough. Pressing the flusher 1600 also collapses the second
dome 1606B, eventually opening the flush valve 1608 to emit a high
pressure cough of fluid through the ventricle port 1602. Because
the first control valve 1612A is closed, the fluid of the first
flush dome 1606A is not included in the cough of fluid and does not
contribute to the pressure or volume of the flushing operation. The
flushing operation is therefore a first flush of the type described
above (e.g., a flush having reduced pressure and/or volume).
[0185] The flusher 1600 is also operable in an unrestricted
operating mode in which the first control valve 1612A is open and
the second control valve 1612B is closed. In the unrestricted
operating mode, pressing the flusher 1600 collapses the first dome
1606A. Fluid in the first flush dome 1606A cannot escape through
the closed second control valve 1612B and instead flows through the
open first control valve 1612A to combine with the fluid in the
second flush dome 1606B. Pressing the flusher 1600 also collapses
the second dome 1606B, eventually opening the flush valve 1608 to
emit a high-pressure cough of fluid through the ventricle port
1602. The resulting cough of fluid includes the fluid from both the
first and second flush domes 1606A, 1606B. The flushing operation
is therefore a second flush of the type described above (e.g., a
flush having increased pressure and/or volume).
[0186] FIGS. 17A-17B illustrate an exemplary catheter 1701 that can
be used in the shunt systems described herein. The catheter 1701
includes one or more primary flow ports 1703 and one or more
auxiliary flow ports 1705. The auxiliary flow port 1705 can be
initially closed or blocked and selectively opened to provide an
alternative path for fluid to flow through the catheter 1701, e.g.,
when the primary flow port 1703 becomes clogged. The auxiliary flow
port 1705 can be configured to open in response to a non-invasive,
extracorporeal input applied thereto. For example, a periphery of
the auxiliary flow port 1705 can be defined by a shape memory frame
1707 embedded in or coupled to the sidewall of the catheter. The
shape memory frame 1707 can be initially retained as shown in FIG.
17A to hold the auxiliary flow port 1705 closed. The shape memory
frame 1707 can be released to allow the shape memory frame to
return to a resting state in which the auxiliary flow port 1705 is
open, as shown in FIG. 17B. The shape memory frame 1707 can be
released by applying an electrical signal to a metallic clip
holding the frame closed to melt the clip and release the frame.
The shape memory frame 1707 can be released by applying a magnetic
field to a metallic or magnetic clip holding the frame closed to
move the clip and release the frame. The shape memory frame 1707
can be formed from Nitinol or other materials with resilient or
shape memory properties. The frame 1707 can completely surround the
auxiliary flow port 1705, or can be formed as one or more discrete
leaf springs positioned adjacent to the auxiliary flow port. In
some instances, only a qualified clinician is able to apply the
input to open the auxiliary flow port 1705. Accordingly, a patient
can flush the catheter 1701 as needed without opening the auxiliary
flow port 1705.
[0187] FIGS. 18A-18B illustrate an exemplary flusher 1800 and
extracorporeal flush device 1836 that can be used in the shunt
systems described herein. The flusher 1800 includes a first flush
dome 1806A and a second flush dome 1806B separated by a control
valve 1812 (e.g., a magnetically-actuated control valve). The flush
device 1836 has a skin-contacting surface with a recess 1838 formed
therein that defines a substantial negative of the flusher 1800,
except that the recess includes a projection 1840 configured to
bear against and collapse the second flush dome 1806B when the
flush device is pressed down over the implanted flusher 1800. The
geometry of the projection 1840 can be selected or calibrated to
apply the desired force to the second flush dome 1806B or to
displace the desired volume of fluid from the second flush dome
1806B. The first flush dome 1806A can have a smaller volume and/or
can be coupled to a flush valve having a lower opening pressure.
The second flush dome 1806B can have a greater volume and/or be
coupled to a flush valve having a greater opening pressure.
Accordingly, in some embodiments, actuating the first flush dome
1806A would only be effective to clear a primary flow port of the
catheter and would not be effective to open an auxiliary flow port
of the catheter, whereas actuating the second flush dome 1806B
would be sufficient to open the auxiliary flow port.
[0188] The flusher 1800 is operable in a restricted mode in which
the control valve 1812 is closed such that only the first flush
dome 1806A can be actuated to emit a flushing cough through the
ventricle port 1802 of the flusher. The closed control valve 1812
prevents a flushing cough from exiting the second flush dome 1806B
if the second flush dome is pressed while in the restricted
mode.
[0189] The flusher 1800 is operable in an unrestricted mode in
which the control valve 1812 is open. In the unrestricted mode, the
second flush dome 1806B can be actuated to emit a flushing cough
through the ventricle port 1802 of the flusher. As noted above, the
cough emitted by the second flush dome 1806B can be greater than
that of the first flush dome 1806A, such that the cough is
sufficient to open an auxiliary flow port of the ventricular
catheter. In use, the flusher 1800 would normally be in the
restricted mode. When it is desired to open an auxiliary flow path,
a clinician could apply an external magnetic field or other input
to switch the flusher 1800 to the unrestricted mode and then place
the flush device 1836 over the implanted flusher to emit a
calibrated flush that opens the auxiliary flow path. It will be
appreciated that the flusher 1800 can be used without the flush
device 1836, e.g., using simple manual finger pressure. It will
further be appreciated that a flush device such as the illustrated
flush device 1836 can be used with any of the flushers disclosed
herein.
[0190] FIG. 19 illustrates an exemplary ventricular catheter 1901
that can be used in the shunt systems described herein. The
catheter 1901 includes one or more primary flow ports 1903 and one
or more auxiliary flow ports 1905. The auxiliary flow port 1905 can
be initially closed or blocked and selectively opened to provide an
alternative path for fluid to flow through the catheter 1901, e.g.,
when the primary flow port 1903 becomes clogged. The catheter 1901
can include first and second lumens 1901A, 1901B, the first lumen
being in communication with the primary flow port 1903 and the
second lumen being in communication with the auxiliary flow port
1905. The second lumen 1901B can be sealed off from the first lumen
1901A by a one-way pressure-dependent valve 1912. In use, a
flushing cough delivered to the catheter 1901 below the opening
pressure threshold of the valve 1912 would be directed only towards
the primary flow port 1903. A flushing cough delivered to the
catheter 1901 at or above the opening pressure threshold of the
valve 1912 would cause the valve to open and direct the flushing
cough to the auxiliary flow port 1905 to open the auxiliary flow
port. The catheter 1901 can be used with flushers of the type
described herein having an adjustable cough pressure. For example,
the flusher of FIGS. 2A-2J can be used with the catheter 1901. The
flush valve can be adjusted (e.g., using an extracorporeal
adjustment input such as a magnetic force) to a relatively low
opening pressure to place the system in a restricted mode in which
flushing coughs emitted by the flusher 200 travel only through the
first lumen 1901A of the catheter 1901. The flush valve can be
adjusted to a relatively higher opening pressure to place the
system in an unrestricted mode in which flushing coughs emitted by
the flusher 200 have sufficient pressure to open the valve 1912 of
the catheter 1901 and travel through the second fluid lumen 1901B
to the auxiliary flow port 1905. As another example, any of the
"dual-flush" flushers disclosed herein can be used with the
catheter 1901.
[0191] FIG. 20 illustrates an exemplary catheter 2001 that can be
used in the shunt systems described herein. The catheter 2001
includes one or more primary flow ports 2003 and one or more
auxiliary flow ports 2005. The auxiliary flow port 2005 can be
initially closed or blocked and selectively opened to provide an
alternative path for fluid to flow through the catheter 2001, e.g.,
when the primary flow port 2003 becomes clogged. The auxiliary flow
port can be covered by a membrane defined between an interior of
the catheter and an exterior of the catheter. Alternatively, as
shown, a membrane 2009 can partition off a distal portion of the
catheter 2001 with auxiliary flow ports 2005 formed therein. When
the membrane 2009 is ruptured, fluid can flow through the catheter
2001 via the distal auxiliary flow ports 2005. The catheter 2001
can include a connector 2011 at a proximal end of the catheter for
selectively coupling the catheter to various flushers. The catheter
2001 can be provided as a kit with a first flusher (e.g., a patient
flusher) and a second flusher (e.g., a clinician flusher). The
second flusher can be configured to deliver a flushing cough with a
pressure and/or a volume that is greater than that of the first
flusher. The pressure and/or volume of the flush emitted by the
first flusher can be insufficient to open the auxiliary flow port.
Accordingly, when the first flusher is used with the catheter 2001,
only the primary flow ports are cleared of obstructions and the
auxiliary flow port cannot be opened. When the second flusher is
used with the catheter 2001, the pressure and/or volume can be
sufficient to open the auxiliary flow port.
[0192] FIG. 21 illustrates an exemplary catheter 2101 that can be
used in the shunt systems described herein. The catheter 2101
includes one or more primary flow ports 2103 and one or more
auxiliary flow ports 2105. The auxiliary flow port 2105 can be
initially closed or blocked and selectively opened to provide an
alternative path for fluid to flow through the catheter 2101, e.g.,
when the primary flow port 2103 becomes clogged. The catheter 2101
can include a partition 2109 with an adjustable aperture size. The
aperture size can be adjusted remotely, e.g., using an
extracorporeal control device. For example, an external magnetic
field or an electrical signal can be applied to adjust the size of
the aperture. In some embodiments, the partition 2109 can be an
electronically-controlled iris. The partition 2109 can be formed
from various materials, including electroactive polymers configured
to change shape in response to an electrical signal applied
thereto. The catheter 2101 is operable in a restricted mode in
which the aperture is closed to seal off open auxiliary flow ports
of the catheter disposed distal to the partition 2109, or in which
the aperture is open to a relatively small size to limit the volume
and/or pressure of a flushing cough passing therethrough such that
the force is insufficient to open closed auxiliary flow ports 2105
distal to the partition. The catheter 2101 is operable in an
unrestricted mode in which the aperture is open to allow open
auxiliary flow ports of the catheter disposed distal to the
partition 2109 to be used, or to allow sufficient flushing volume
or pressure to pass through the aperture to open closed auxiliary
flow ports 2105 distal to the partition.
[0193] FIG. 22 illustrates an exemplary catheter 2201 that can be
used in the shunt systems described herein. The catheter 2201 is
similar to the catheter 2101 described above, except that the
catheter 2201 includes a pneumatically actuated partition 2209. The
partition 2209 can include a balloon with an inflation lumen
coupled thereto configured to supply or remove an inflation medium
from the balloon. The balloon can include a flow path extending
therethrough. In use, the balloon can be inflated to open the
otherwise closed flow path. In an alternative arrangement, the
balloon can be deflated to open the otherwise closed flow path, or
to form a flow path around the balloon through which fluid can
flow.
[0194] FIG. 23 illustrates an exemplary method of opening an
auxiliary flow port 2305 in a catheter 2301. As shown, a syringe
2336 or other device can be used to pierce or puncture a flush dome
2306 of an implanted flusher 2300, e.g., a shunt tap dome of the
flusher. The syringe 2336 can be used to aspirate fluid from the
shunt system, creating a negative pressure in the system sufficient
to open a membrane of an auxiliary flow port 2305 in the catheter
2301. The syringe 2336 can also be used to inject fluid into the
shunt system, creating a positive pressure in the system sufficient
to open a membrane of an auxiliary flow port 2305 in the catheter
2301.
[0195] FIG. 24 illustrates an exemplary flusher 2400 that can be
used in the shunt systems herein. The flusher 2400 includes a flush
dome 2406A and a negative pressure reservoir 2406B. The negative
pressure reservoir 2406B can be disposed within the flush dome
2406A as shown, or elsewhere within the flusher 2400. The negative
pressure reservoir 2406B can be vacuum sealed during manufacturing
such that a negative pressure is maintained in the reservoir 2406B.
In use, the reservoir 2406B can be selectively activated, e.g., by
placing the reservoir 2406B in fluid communication with the flush
dome 2406A, to expose a catheter 2401 coupled to the flusher 2400
to a negative pressure sufficient to open a membrane of an
auxiliary flow port 2405 in the catheter. The reservoir 2406B can
be activated in various ways, such as by piercing the reservoir
with a needle, applying a magnetic field to open a valve that seals
the reservoir, etc.
[0196] FIG. 25 illustrates an exemplary flusher 2500 and catheter
2501 that can be used in the shunt systems described herein. The
catheter 2501 includes one or more primary flow ports 2503 and one
or more auxiliary flow ports 2505. The auxiliary flow port 2505 can
be initially closed or blocked and selectively opened to provide an
alternative path for fluid to flow through the catheter 2501, e.g.,
when the primary flow port 2503 becomes clogged. The catheter 2501
can include first and second lumens 2501A, 2501B, the first lumen
being in communication with the primary flow port 2503 and the
second lumen being in communication with the auxiliary flow port
2505. The second lumen 2501B can be sealed off from the first lumen
2501A by a magnetically-actuated flap or valve 2512. In use, a
flushing cough delivered to the catheter 2501, e.g., using a
flusher 2500 of the type described herein) is normally directed
only towards the primary flow port 2503. When a magnetic field is
applied to the flap or valve 2512, e.g., using an extracorporeal
device, the valve opens to direct the flushing cough to the
auxiliary flow port 2505 to open the auxiliary flow port. The valve
2512 can be disposed in the catheter 2501 as shown to change the
fluid path through the catheter, or can be disposed in the flusher
2500 to change the fluid path through the catheter.
[0197] FIG. 26 illustrates an exemplary flusher 2600 and catheter
2601 that can be used in the shunt systems described herein. The
catheter 2601 includes one or more primary flow ports 2603 and one
or more auxiliary flow ports 2605. The auxiliary flow port 2605 can
be initially closed or blocked and selectively opened to provide an
alternative path for fluid to flow through the catheter 2601, e.g.,
when the primary flow port 2603 becomes clogged. The catheter 2601
can include first and second lumens 2601A, 2601B, the first lumen
being in communication with the primary flow port 2603 and the
second lumen being in communication with the auxiliary flow port
2605. The second lumen 2601B can be sealed off from the first lumen
2601A. The first lumen 2601A is in fluid communication with a flush
dome 2606A of the flusher 2600. Accordingly, actuation of the flush
dome 2606A, e.g., by a patient, can be effective to clear
obstructions from the primary flow port 2603. The second lumen
2601B is in fluid communication with a port 2606B of the flusher
2600, which can be formed, for example, as a pierceable membrane.
An external flusher or syringe can be coupled to the port 2606B to
direct negative vacuum pressure or positive flushing pressure
through the second lumen 2601B to open an auxiliary flow port 2605.
Typically, only a qualified clinician would couple an external
flusher to the port 2606B and be able to open the auxiliary flow
port 2605. Flushing the second lumen 2601B can also be effective to
open a recirculation flow path 2613 between the first and second
lumens 2601A, 2601B. This can allow fluid to be shunted through the
auxiliary flow port 2605 and through the flusher 2600 after the
flushing operation is performed. The second lumen 2601B of the
catheter can be vacuum sealed prior to use to limit or prevent air
from entering the system.
[0198] FIG. 27A illustrates an exemplary catheter 2701 that can be
used in the shunt systems described herein. The catheter 2701
includes one or more primary flow ports 2703 and one or more
auxiliary flow ports 2705. The auxiliary flow port 2705 can be
initially closed or blocked and selectively opened to provide an
alternative path for fluid to flow through the catheter 2701, e.g.,
when the primary flow port 2703 becomes clogged. The auxiliary flow
port 2705 can be initially blocked by an inner or outer sheath 2715
coaxially disposed within or over the catheter body 2717. The
sheath 2715 can include one or more openings 2719 formed therein
configured to be selectively aligned with the auxiliary flow port
2705 of the catheter. When the opening 2719 of the sheath 2715 is
not aligned with the auxiliary flow port 2705, a flushing operation
delivered to the catheter is only effective to clear the primary
flow port 2703, and does not reach the auxiliary flow port. When
the opening 2719 of the sheath 2715 is aligned with the auxiliary
flow port 2705, a flushing operation delivered to the catheter
reaches the auxiliary flow port and can open the port.
[0199] The opening 2719 of the sheath 2715 can be aligned with the
auxiliary flow port 2705 by rotating the sheath relative to the
catheter body 2717 about a longitudinal axis thereof as shown in
FIGS. 27A-27B. The sheath 2715 can include multiple openings 2719
spaced along the length of the sheath and staggered about the
circumference of the sheath, as shown in the catheter 2701' of FIG.
27B. The catheter body 2717 can include auxiliary flow ports 2705
formed in a corresponding pattern, but staggered by a greater
distance about the circumference. This can allow incremental
rotation of the sheath 2715 to open additional auxiliary flow ports
2705, allowing the system to be used multiple times to form
auxiliary flow paths. For example, rotating the sheath to a first
degree can align a first opening of the sheath with a first
auxiliary flow port without opening a second auxiliary flow port.
Rotating the sheath to a second degree that is greater than the
first degree can align a second opening of the sheath with the
second auxiliary flow port without opening a third auxiliary flow
port, and so on.
[0200] As shown in FIGS. 28A-28B, a catheter 2801 can include a
sheath 2815 that includes a single, longitudinally-elongated
opening 2819 configured to be selectively aligned with one or more
of a plurality of auxiliary flow ports 2805 formed in the catheter.
The auxiliary flow ports 2805 are spaced along the length of the
catheter 2801 and staggered about the circumference of the
catheter. The catheter 2801 operates in a manner similar to the
catheter 2701 described above.
[0201] Rotation of the sheath 2815 relative to the catheter body
2817 can be controlled in various ways. For example, as shown in
FIG. 28B, a proximal end of the catheter body 2817 can be coupled
to a magnetically-actuated disc 2821 configured to rotate in
response to an externally-applied magnetic field. The disc 2821 can
rotate relative to a base plate 2823 to which the sheath 2815 is
coupled. Accordingly, rotation of the disc 2821 relative to the
base plate 2823 is effective to rotate the sheath 2815 relative to
the catheter body 2817. The disc 2821 can be configured to lock
into one of a plurality of discrete rotational positions. For
example, a magnetic field can be applied to lift the disc, rotate
it, and then drop it back down into the next successive rotational
position. The disc 2821 can include a locking pin projecting
therefrom configured to be received in any of a plurality of
discrete recesses disposed about a circumference of the base plate
2823. The disc 2821 can be integrated into a burr hole anchor, a
Rickham-style reservoir, or a flusher of the type described
herein.
[0202] As another example, the sheath can be hydraulically-actuated
such that fluid pressure, e.g., supplied from an external syringe
or from a flusher, acts on the sheath to rotate the sheath relative
to the catheter. As another example, the catheter can be used with
dual-pressure or dual-volume flushers of the type described herein.
Low-pressure or low-volume flushes emitted by such devices can be
insufficient to rotate the sheath and therefore would not open an
additional auxiliary flow port. High-pressure or high-volume
flushes emitted by such devices can be sufficient to rotate the
sheath and therefore open an additional auxiliary flow port. As
another example, the catheter can be used with a single-volume or
single-pressure flusher. When a flushing operation is performed
that is sufficient to clear the primary flow port, the pressure in
the system remains below a threshold pressure required to rotate
the sheath. When the flushing operation is insufficient to clear
the primary flow port, the pressure in the system can increase to a
level sufficient to cause the sheath to rotate and thereby open an
auxiliary flow port. As another example, the sheath can be formed
from an electroactive polymer and an electrical signal can be
applied thereto to move the sheath or adjust the shape of the
sheath. As another example, a stepper motor or other mechanical
element can be used to rotationally index the sheath.
[0203] FIG. 29 illustrates a catheter 2901 that operates in a
manner similar to the catheters 2701, 2801 described above, except
that the sheath 2915 translates longitudinally relative to the
catheter body 2917 instead of or in addition to rotating relative
to the catheter body. The catheter body 2917 includes a plurality
of auxiliary flow ports 2905 spaced along a length of the catheter.
The sheath 2915 includes an opening 2919 configured to be aligned
with each of the auxiliary flow ports 2905 as the sheath translates
axially along the catheter body 2917. The sheath 2915 can be
initially placed in a distal-most position to align the opening
2919 with a distal auxiliary flow port 2905 of the catheter. When
it is desired to open a different auxiliary flow port, the sheath
2915 can be retracted proximally to align the opening 2919 with
said flow port. In other embodiments, the sheath 2915 can operate
in the opposite direction, e.g., sliding the sheath distally
relative to the catheter body 2917 to open successive auxiliary
flow ports 2905.
[0204] Longitudinal translation of the sheath 2915 can be
controlled in various ways. For example, the proximal end of the
sheath 2915 can be coupled to a disc having a stepped or tapered
surface such that rotation of the disc against a base plate, e.g.,
via an external magnetic field or via fluid pressure from a syringe
or flusher, adjusts a longitudinal position of the sheath 2915
relative to the base plate and relative to the catheter body 2917.
The sheath 2915 can be rotatably coupled to the disc such that
rotation of the disc does not cause the sheath to rotate. As noted
above, the sheath 2915 can be disposed within the catheter body
2917 or can be disposed about an exterior surface of the catheter
body. As another example, the sheath 2915 can be formed from an
electroactive polymer and an electrical signal can be applied
thereto to move the sheath or adjust the shape of the sheath. As
another example, a stepper motor or other mechanical element can be
used to longitudinally index the sheath 2915.
[0205] FIG. 30 illustrates an exemplary catheter 3001 that can be
used in the shunt systems described herein. The catheter 3001
includes one or more primary flow ports 3003 and one or more
auxiliary flow ports 3005. The auxiliary flow port 3005 can be
initially closed or blocked and selectively opened to provide an
alternative path for fluid to flow through the catheter 3001, e.g.,
when the primary flow port 3003 becomes clogged. A thin wire 3025
is initially disposed across the auxiliary flow port 3005. The wire
3025 can act as a strut to reinforce the membrane of the auxiliary
flow port 3005 to prevent it from being opened. Alternatively, or
in addition, the wire 3025 can cover a portion of the auxiliary
flow port 3005 to limit the surface area of the membrane that is
exposed to a flushing operation to prevent the auxiliary flow port
from opening. A distal end 3027 of the wire 3025 can be atraumatic
or sealed within the catheter to prevent patient injury. In use,
the wire 3025 can be severed or retracted proximally to open the
auxiliary flow port 3005 or to allow the auxiliary flow port to be
opened by a flushing operation. The wire 3025 can also be used to
control the threshold pressure required to open the membrane, e.g.,
by selecting a wire having a thickness or material properties
calibrated to the desired opening pressure. The wire can be severed
or retracted in various ways. For example, an electric current can
be applied to the wire to sever the wire. As another example, an
external magnetic field can be applied to the wire to withdraw the
wire proximally. As another example, a proximal end of the wire can
be disposed around a spool, e.g., formed in a flusher or burr hole
cap, that can be rotated by a magnetic field or by fluid pressure
to wind up the wire and pull the wire proximally.
[0206] FIG. 31 illustrates an exemplary flusher 3100 that can be
used in the shunt systems described herein. The flusher includes a
first flush valve 3108A and a second flush valve 3108B that have
different opening pressures. For example, the first flush valve
3108A can be configured to open at a lower threshold pressure than
the second flush valve 3108B. The flush dome 3106 of the flusher
3100 can be selectively coupled to one of the two flush valves
3108A, 3108B by a diverter 3112. The diverter 3112 can be actuated
to connect the flush dome 3106 to the first flush valve 3108A,
e.g., to place the flusher in a restricted mode in which flushing
pressure is insufficient to open an auxiliary flow port. The
diverter 3112 can be actuated to disconnect the flush dome 3106
from the first flush valve 3108A and instead connect the flush dome
3106 to the second flush valve 3108B, e.g., to place the flusher in
an unrestricted mode in which flushing pressure is sufficient to
open an auxiliary flow port. Typically, the diverter 3112 would be
positioned in the restricted mode for patient use and then switched
to the unrestricted mode when a clinician or other qualified
operator wishes to open an auxiliary flow port. The diverter 3112
can be controlled in various ways. For example, the diverter can be
a magnetically or electronically-actuated valve. The diverter can
be actuated non-invasively, e.g., using an extracorporeal
controller.
[0207] FIG. 32 illustrates an exemplary catheter 3201 that can be
used in the shunt systems described herein. The catheter 3201
includes one or more primary flow ports 3203 and one or more
auxiliary flow ports 3205. The auxiliary flow port 3205 can be
initially closed or blocked and selectively opened to provide an
alternative path for fluid to flow through the catheter 3201, e.g.,
when the primary flow port 3203 becomes clogged. The catheter 3201
can include one or more sensors 3229 configured to detect when an
auxiliary flow port 3205 is opened and generate a signal in
response thereto that can provide feedback to a user as to whether
the flow port was opened. Exemplary sensors 3229 include acoustic
sensors configured to detect sound waves emitted by a membrane
disposed over the auxiliary flow port 3205 when the membrane
ruptures. The sensors 3229 can be disposed adjacent to the
auxiliary flow ports 3205 as shown, or can be positioned at various
other locations along the catheter 3201.
[0208] FIG. 33 illustrates an exemplary catheter 3301 that can be
used in the shunt systems described herein. The catheter 3301
includes one or more primary flow ports 3303 and one or more
auxiliary flow ports 3305. The auxiliary flow port 3305 can be
initially closed or blocked and selectively opened to provide an
alternative path for fluid to flow through the catheter 3301, e.g.,
when the primary flow port 3303 becomes clogged. The catheter 3301
can include a first fluid lumen 3301A having a first primary flow
port 3303A and a first auxiliary flow port 3305A and a second fluid
lumen 3301B having a second primary flow port 3303B and a second
auxiliary flow port 3305B. A diverter valve can be disposed between
the first and second lumens 3301A, 3301B and a flusher 3300 of the
type described herein to control which of the lumens is placed in
fluid communication with the flusher.
[0209] In use, the valve can be initially configured such that the
first lumen 3301A is in fluid communication with the flusher 3300,
e.g., by swinging a partition defined by the valve to the right in
the drawing. In this configuration, a low pressure flush operation
can be used to clear obstructions from the first primary flow port
3303A and a high pressure flush operation can be used to open the
first auxiliary flow port 3305A. If it is desired to open
additional flow paths, the valve 3312 can be switched to place the
second fluid lumen 3301B in fluid communication with the flusher
3300, e.g., by swinging a partition defined by the valve to the
left in the drawing. In this switched configuration, the first
fluid lumen 3301A is sealed off and fluid is shunted through the
second fluid lumen 3301B. A low pressure flush operation can be
used to clear obstructions from the second primary flow port 3303B
and a high pressure flush operation can be used to open the second
auxiliary flow port 3305B. The illustrated catheter 3301 can thus
provide at least four different flow paths to provide multiple
stages of restoring flow through the system.
[0210] In some embodiments, a flusher can include a compliance
feature in communication with the flush path through the catheter.
The compliance feature can be an expandable compartment, e.g., a
balloon, a hydraulic accumulator, etc., that absorbs at least some
of the volume and/or pressure of a flushing cough to prevent the
flushing cough from opening an auxiliary flow port through the
system while still allowing the flushing cough to clear primary
flow ports of the system. A non-invasive control of the type
described herein can be used to selectively fluidly-isolate the
compliance feature from the flush path to allow a flushing
operation to open an auxiliary flow port through the system.
Exemplary non-invasive controls include remotely-actuated valves,
e.g., magnetically-actuated valves.
[0211] FIGS. 34A-34C illustrate an exemplary flusher 3400 that
includes a compliant feature 3452. The compliant feature 3452 can
be formed integrally with the flusher 3400, e.g., in the same outer
housing or unit as the flush dome 3404, or can be a separate
component as shown. The compliant feature 3452 can include an
upstream port 3454 in fluid communication with a ventricle or drain
catheter, a downstream port 3456 in fluid communication with the
flush dome 3404, and a fluid path 3458 connecting the upstream and
downstream ports. The fluid path 3458 can be defined at least in
part by a groove or recess formed in a base plate 3460 of the
compliant feature 3452. The fluid path 3458 can be in fluid
communication with the interior of an elastic membrane 3462. The
elastic membrane 3462 can normally lay flat against the base plate
3460 as shown in FIG. 34B, but can expand away from the base plate
when fluid is supplied thereto under pressure, as shown in FIG.
34C. The flusher 3400 is normally configured in a restricted
operating mode. In the restricted operating mode, passive flow
through system occurs through the fluid path 3458. In this
operating mode, actuation of the flusher 3400 releases a cough of
fluid that causes the elastic membrane 3462 to transition from the
state shown in FIG. 34B to the state shown in FIG. 34C. In doing
so, the elastic membrane 3462 absorbs some or all of the volume
and/or pressure of the flush, preventing the flush from being
applied to the ventricular catheter or limiting the degree to which
the flush is applied to the ventricular catheter. When actuation of
the flusher 3400 ceases, the fluid in the compliant feature 3452
can drain out through the passive flow path. The flusher 3400 can
also be used in an unrestricted operating mode. In the unrestricted
operating mode, a clinician or other user can hold the membrane
3462 in the state shown in FIG. 34B. With the membrane 3462
constrained from expanding, a flushing cough emitted in the
unrestricted mode can be communicated to the ventricular catheter,
e.g., to open an auxiliary flow port therethrough. The membrane
3462 can be held in the state shown in FIG. 34B by manual finger
pressure through the patient's skin, or by pressure applied by a
specialized tool positioned over the patient's skin against the
upper surface of the compliant feature 3452.
[0212] FIG. 35 illustrates an exemplary flusher 3500 that includes
a compliant feature 3552. The compliant feature 3552 can be formed
integrally with the flusher 3500, e.g., in the same outer housing
or unit as the flush dome 3504, or can be a separate component as
shown. The compliant feature 3552 can include any of the features
of the compliant feature 3452 described above. The flusher 3500 can
include a control 3514. The control 3514 can be configured to
selectively isolate the compliant feature 3552 from the flush path,
and to selectively include the compliant feature in the flush path.
Accordingly, the control 3514 can be switched between a restricted
mode, in which the compliant feature 3552 is in communication with
the flush path and absorbs some or all of a flush emitted from the
flusher 3500, and an unrestricted mode, in which the compliant
feature is isolated from the flush path such that a flush emitted
from the flusher is applied to the catheter, e.g., to open an
auxiliary flow path through the catheter. Exemplary controls can
include valves, sliding controls, switches, and so forth. The
control 3514 can be non-invasively actuated.
[0213] In some embodiments, a flusher can include a first flush
dome (e.g., a patient flush dome) and a second flush dome (e.g., a
clinician flush dome). The pressure and/or volume of the flush
emitted from the first flush dome can be less than that of the
second flush dome, such that actuating the first flush dome is
insufficient to open an auxiliary flow port while actuation of the
second flush dome is sufficient to open an auxiliary flow port. A
non-invasive control of the type described herein can be used to
selectively fluidly-isolate the second flush dome from the flush
path to prevent opening of an auxiliary flow port and to
fluidly-couple the second flush dome to the flush path to permit
opening of an auxiliary flow port. Exemplary non-invasive controls
include remotely-actuated valves, e.g., magnetically-actuated
valves.
[0214] In some embodiments, a flusher can include a first flush
valve (e.g., a patient flush valve) and a second flush valve (e.g.,
a clinician flush valve). The pressure and/or volume of the flush
emitted from the first flush valve can be less than that of the
second flush valve, such that actuating the first flush valve is
insufficient to open an auxiliary flow port while actuation of the
second flush valve is sufficient to open an auxiliary flow port. A
non-invasive control of the type described herein can be used to
selectively fluidly-isolate the second flush valve from the flush
path to prevent opening of an auxiliary flow port and to
fluidly-couple the second flush valve to the flush path to permit
opening of an auxiliary flow port. Exemplary non-invasive controls
include remotely-actuated valves, e.g., magnetically-actuated
valves.
[0215] In some embodiments, a flusher can include a flush dome with
an adjustable volume. The volume can be adjusted non-invasively
between a first setting (e.g., a patient setting) in which the
volume of a flush emitted from the flush dome is insufficient to
open an auxiliary flow port and a second setting (e.g., a clinician
setting) in which the volume of a flush emitted from the flush dome
is sufficient to open an auxiliary flow port. The volume can be
adjusted non-invasively using a non-invasive control of the type
described herein. In one example, a movable shim can be positioned
in the flush dome to reduce the volume. In another example, a
threaded component can be threaded into the interior of the flush
dome to decrease the volume of the flush dome. In another example,
the flush dome can include a needle tap to allow additional fluid
to be injected into the flush dome from a syringe.
[0216] FIG. 36 illustrates an exemplary flusher 3600 with an
adjustable flush volume. One or more surfaces of the flush cavity
3604 can be movable to alter the resting or effective volume of the
flush cavity. For example, as shown, the lower surface of the flush
cavity 3604 can be defined by a threaded plate 3664 threaded into a
recess of the flush cavity. The plate 3664 can be rotated to
translate the plate relative to the flush cavity 3604 along an axis
A1. In particular, rotation of the plate 3664 in a first direction
can move the plate upwards to reduce the volume of the flush cavity
3604, and rotation of the plate in a second, opposite direction can
moved the plate downwards to increase the volume of the flush
cavity. While a threaded interface is shown, it will be appreciated
that various other mechanical couplings can be used to move the
plate 3664. The plate 3664 can be actuated remotely, e.g., via an
extracorporeal magnetic field. In a restricted mode, the plate 3664
can be raised to limit the volume and/or pressure of the flush. In
an unrestricted mode, a control can be actuated to lower the plate
3664 and allow a higher volume and/or higher pressure flush to be
generated.
[0217] FIG. 37 illustrates an exemplary flusher 3700 with an
adjustable flush volume. An inflatable member 3766 can be disposed
within the flush cavity 3704 and can be inflatable or deflatable to
adjust the resting or effective volume of the flush cavity. The
inflatable member 3766 can be inflated via a non-invasive control.
The inflatable member 3766 can include a needle tap to allow the
inflatable member to be inflated or deflated with a syringe or
other minimally-invasive injector. In a restricted mode, the
inflatable member 3766 can be inflated to limit the volume and/or
pressure of the flush. In an unrestricted mode, a control can be
actuated to deflate the inflatable member 3766 and allow a higher
volume and/or higher pressure flush to be generated.
[0218] FIG. 38 illustrates an exemplary flusher 3800 with an
adjustable flush volume. A movable member 3868 can be movably
mounted in the flusher and can be selectively advanced into the
flush cavity 3804 or retracted from the flush cavity to alter the
resting or effective volume of the flush cavity. For example, as
shown, a block 3868 can be mounted in a side pocket 3870 of the
flusher 3800 and can slide along an axis A1 between a fully
retracted and a fully advanced position. As the block 3868 is
advanced into the flush cavity 3804, the block occupies at least a
portion of the flush cavity volume, displacing fluid therefrom and
thereby limiting the flush. The block 3868 can be controlled by a
magnetically-rotatable threaded shaft, a solenoid actuator, a
linear actuator, an injectable volume, or other control 3872. The
block 3868 can be non-invasively controlled, e.g., by applying a
magnetic field or other force from a location outside the patient
in which the flusher 3800 is implanted. In a restricted mode, the
movable member 3868 can be advanced into the flush cavity 3804 to
limit the volume and/or pressure of the flush. In an unrestricted
mode, a control can be actuated to withdraw the movable member 3868
from the flush cavity 3804 and allow a higher volume and/or higher
pressure flush to be generated.
[0219] In some embodiments, a flusher can include a flush valve
with an adjustable opening pressure. The pressure can be adjusted
non-invasively between a first setting (e.g., a patient setting) in
which the pressure of a flush emitted from the flusher is
insufficient to open an auxiliary flow port and a second setting
(e.g., a clinician setting) in which the pressure of a flush
emitted from the flusher is sufficient to open an auxiliary flow
port. The pressure can be adjusted non-invasively using a
non-invasive control of the type described herein. In one example,
a magnetically-rotatable disc can be rotated to adjust the pre-load
on a spring holding the flush valve closed or the pressure on a
deformable valve body pressed against a valve seat.
[0220] In some embodiments, a catheter can include multiple
membranes covering respective auxiliary flow ports, the membranes
varying in thickness, composition, dimensions, or other material
properties to require progressively higher burst volumes and/or
pressures to open their respective flow ports.
[0221] In some embodiments, a Rickham-style reservoir or skull
anchor can include a tuned compliance feature. The compliance
feature can be an expandable compartment, e.g., a balloon, a
hydraulic accumulator, etc., that absorbs at least some of the
volume and/or pressure of a flushing cough to prevent the flushing
cough from opening an auxiliary flow port through the system while
still allowing the flushing cough to clear primary flow ports of
the system. A specialized extracorporeal tool can be positioned
over the compliance feature to block expansion of the compliance
feature, thereby limiting or preventing the flush from being
absorbed and allowing the flush to instead open an auxiliary flow
port. The extracorporeal tool can be a plate with a recess formed
therein that forms a negative of the compliance feature when the
compliance feature is in an unexpanded state.
[0222] A number of flushers are disclosed herein that include a
pinch tube to occlude a drain side of the system during a flushing
operation. In some embodiments, the pinch tube can be omitted and a
non-invasively adjustable valve can be included in the flusher to
selectively block the drain side of the system. In some
embodiments, the non-invasively adjustable valve can be a shunt
valve that in non-flushing conditions regulates flow through the
system to regulate the pressure within the patient's ventricle.
[0223] It will be appreciated that, in any of the flusher
embodiments above, the pinch tube or lumen can be disposed below
the flush dome instead of on top of the flush dome as shown.
[0224] In any of the flushers disclosed herein, the flush dome can
be sized to control the volume of fluid flushed through the shunt
system during a flushing operation. In an exemplary embodiment, the
flush dome has an interior volume of about 1 mL. In another
exemplary embodiment, the flush dome has an interior volume of
about 0.5 mL. The volume of the flush dome can be less than about 2
mL, less than about 1 mL, less than about 0.75 mL, and/or less than
about 0.5 mL. The volume of the flush dome can be in the range of
about 0.25 mL to about 0.75 mL. In any of the flushers disclosed
herein, the flush dome can be configured to rebound or return to
its un-collapsed configuration at a slow rate to prevent reflux
action from sucking debris back into the shunt system. For example,
the dome can be formed from a material having low resiliency
properties such as polymeric compositions, silicone, nitrile,
polyurethane, and so forth. Alternatively, or in addition, the dome
can include ribs or other internal or external features for
controlling the rebound rate of the dome. For example, the dome can
include one or more ribs that extend from the base of the dome to
the center peak of the dome. The ribs can extend along the interior
surface of the dome. Alternatively, or in addition, the thickness
of the dome can vary between the base and the peak. For example,
the dome can be thicker at the base than at the peak. While
flushers configured to flush only the upstream or ventricular side
of the shunt system are disclosed herein, it will be appreciated
that the disclosed flushers can be readily modified to flush only
the downstream or drain side of the shunt system and/or to flush
both sides of the shunt system. A number of flushers disclosed
herein include a pinch tube, though it will be appreciated that any
collapsible fluid pathway can be used instead or in addition.
[0225] Although specific embodiments have been described, it should
be understood that numerous changes may be made within the spirit
and scope of the concepts described. Accordingly, it is intended
that the disclosure not be limited to the described
embodiments.
* * * * *