U.S. patent application number 10/082098 was filed with the patent office on 2003-08-28 for retrograde cannula having automatically inflatable balloon.
Invention is credited to Gershowitz, Arthur D..
Application Number | 20030163115 10/082098 |
Document ID | / |
Family ID | 27753035 |
Filed Date | 2003-08-28 |
United States Patent
Application |
20030163115 |
Kind Code |
A1 |
Gershowitz, Arthur D. |
August 28, 2003 |
Retrograde cannula having automatically inflatable balloon
Abstract
Cardioplegia is delivered to a heart vessel by conducting the
cardioplegia through an infusion lumen of a cannula. The
cardioplegia communicates with a balloon disposed on a distal end
of the cannula to cause the cardioplegia to inflate the balloon
into sealing contact with a wall of the coronary sinus. The flow of
cardioplegia is halted while preventing drainage of cardioplegia
from the balloon, to maintain the balloon in its inflated state
until such time as the flow of cardioplegia is resumed. Drainage of
cardioplegia from the balloon is prevented by causing a valve to be
shifted to a closed position blocking communication between the
infusion lumen and the balloon. The valve can be shifted manually,
or automatically in response to the halting of the delivery of
cardioplegia.
Inventors: |
Gershowitz, Arthur D.; (Ann
Arbor, MI) |
Correspondence
Address: |
Platon N. Mandros, Esq.
BURNS, DOANE, SWECKER & MATHIS, L.L.P.
P.O. Box 1404
Alexandria
VA
22313-1404
US
|
Family ID: |
27753035 |
Appl. No.: |
10/082098 |
Filed: |
February 26, 2002 |
Current U.S.
Class: |
604/509 ;
604/99.04 |
Current CPC
Class: |
A61B 2017/00243
20130101; A61M 25/10 20130101 |
Class at
Publication: |
604/509 ;
604/99.04 |
International
Class: |
A61M 031/00 |
Claims
What is claimed is:
1. A retrograde cannula for delivering fluid to a patient's vessel,
the cannula comprising: a body including proximal and distal ends
and an infusion lumen extending therebetween for conducting
pressurized fluid to a lumen outlet arrangement disposed adjacent
the distal end; an automatically inflatable balloon extending
around the body adjacent to, and spaced from, the lumen outlet
arrangement, the balloon receivable in the vessel in a deflated
state and inflatable into sealing contact with a wall of the
vessel, the body including a passage arrangement for fluidly
communicating the balloon with the infusion lumen to enable the
balloon to be inflated by the pressurized fluid conducted through
the infusion lumen; and a valve arranged in the body for being
shifted between an open position to open the passage arrangement,
and a closed position for closing the passage arrangement to keep
the balloon in its inflated state when the delivery of pressurized
fluid is halted.
2. The cannula according to claim 1 wherein the valve is manually
shiftable between the open and closed positions.
3. The cannula according to claim 1 wherein the passage arrangement
comprises a plurality of passages.
4. The cannula according to claim 1 wherein the body further
includes a drain lumen arranged to interconnect the balloon with
the infusion lumen independently of the passage arrangement, the
drain lumen being openable and closable.
5. A retrograde cannula for delivering cardioplegia to a vessel of
a heart, the cannula comprising: a body including proximal and
distal ends and an infusion lumen extending therebetween for
conducting cardioplegia to a lumen outlet arrangement disposed
adjacent the distal end; an automatically inflatable balloon
extending around the body adjacent to, and spaced from, the lumen
outlet arrangement, the balloon receivable in the vessel in a
deflated state and inflatable into sealing contact with a wall of
the vessel, the body including a passage arrangement for fluidly
communicating the balloon with the infusion lumen to enable the
balloon to be inflated by the pressurized cardioplegia conducted
through the infusion lumen; and means for opening the passage
arrangement to communicate the balloon with the infusion lumen, and
for closing the passage to keep the balloon in its inflated state
when the delivery of cardioplegia is halted.
6. The cannula according to claim 5 wherein the body further
includes a drain lumen arranged to interconnect the balloon with
the infusion lumen independently of the passage arrangement, the
drain lumen being openable and closable.
7. A method of delivering cardioplegia to a heart vessel,
comprising the steps of: A. positioning a distal end of a cannula
within the heart vessel; B. conducting a flow of pressurized
cardioplegia through an infusion lumen of the cannula and
discharging the cardioplegia into the heart vessel; C.
communicating the infusion lumen with a balloon disposed on the
distal end, during step B, to cause the cardioplegia to inflate the
balloon into sealing contact with a wall of the heart vessel; D.
halting the flow of cardioplegia through the infusion lumen while
preventing drainage of cardioplegia from the balloon, to maintain
the balloon in its inflated state; and E. thereafter repeating step
B.
8. The method according to claim 7 wherein step D includes causing
a valve to move to a closed position closing a passage arrangement
between the balloon and the infusion lumen.
9. The method according to claim 8 wherein step D further comprises
manually shifting the valve to the closed position.
10. The method according to claim 8, further comprising, subsequent
to step E, the step of opening the valve to drain cardioplegia from
the balloon to reduce the profile thereof prior to withdrawal of
the cannula from the heart vessel.
11. The method according to claim 7, further including, subsequent
to step E, the step of draining cardioplegia from the balloon to
reduce the profile thereof prior to withdrawal of the cannula from
the heart vessel.
12. The method according to claim 11 wherein the draining step
comprises sucking cardioplegia from the balloon by applying suction
to the balloon interior.
13. The method according to claim 11 wherein the draining step
comprises opening a drain lumen for draining cardioplegia from the
balloon to the infusion lumen along a path different from the path
along which the cardioplegia was conducted to the balloon in step
C.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to balloon cannulas, and in
particular to auto-inflate retrograde cannulas used in the delivery
of cardioplegia.
[0002] Retrograde cannulas are commonly employed during certain
cardiac surgical procedures, in order to deliver cardioplegia (CPG)
into coronary veins to effect cardiac arrest of a patient by
depolarizing cell membranes of the heart tissue (see U.S. Pat. No.
5,395,331).
[0003] In order to occlude the coronary sinus, the distal end of
the cannula includes an inflatable balloon which, when inflated,
seals against a wall of the coronary sinus. Balloons may be of the
manual-inflating or auto-inflating type. In a manual-inflating
type, a surgeon inflates the balloon by injecting a set amount
(volume) of fluid therein. However, there exists a risk of
over-inflation of the balloon, which can damage the coronary
sinus.
[0004] The present invention pertains to the auto-inflating type
(also referred to as self-inflating), wherein the balloon is in
fluid communication with an infusion lumen of the cannula and is
thus inflated by pressurized CPG being delivered to the heart.
Thus, the risk of overinflation does not exist because the balloon
is inflated to a pressure rather than to a volume as in the case of
a manual-inflate balloon.
[0005] It will be apparent that the balloon of an auto-inflate
cannula becomes deflated when the delivery of CPG is stopped. The
cannula may thereafter be kept in place during the surgery in order
to be able to periodically administer additional CPG. However, when
the balloon becomes deflated, the distal end of the cannula may
undergo unwanted displacement. This does not occur in the case of a
manual-inflate cannula, but there occurs therein the risk of
overinflation as described above.
[0006] Although it is common to affix the cannula in place by
suturing the cannula to adjacent body tissue, the sutures are
placed behind the balloon and thus are spaced by a few inches from
the distal tip of the cannula. Thus, the portion of the cannula
disposed ahead of the sutures may tend to shift. Such a tendency to
shift is more prevalent during the delivery of warm CPG (and
shiftable) than cold CPG, because the cannula is made more pliant
by the warm CPG.
[0007] Since the ability of the distal end of the cannula to become
displaced results from the deflation of the balloon, it would be
desirable to enable the balloon of an auto-inflate retrograde
balloon to stay inflated even when fluid is not being delivered
through the cannula.
SUMMARY OF THE INVENTION
[0008] The present invention relates to a retrograde cannula for
delivering fluid, such as cardioplegia, to a vessel, such as a
vessel of the heart. The cannula comprises a body which includes
proximal and distal ends and an infusion lumen extending
therebetween for conducting pressurized fluid to a lumen outlet
arrangement disposed adjacent the distal end. An automatically
inflatable balloon extends around the body adjacent to, and spaced
from, the lumen outlet arrangement. The balloon is receivable in
the vessel in a deflated state and is inflatable into sealing
contact with a wall of the vessel. The body includes a passage
arrangement for fluidly communicating the balloon with the infusion
lumen to enable the balloon to be inflated by the pressurized fluid
conducted through the infusion lumen. A valve is arranged in the
body for being shifted between an opened position to open the
passage arrangement, and a closed position for closing the passage
arrangement, to keep the balloon in its inflated state when the
delivery of pressurized fluid is halted.
[0009] The valve can be manually shiftable between the opened and
closed positions, or automatically shiftable between the opened and
closed positions.
[0010] The invention also pertains to a method of delivering
cardioplegia to a heart vessel. The method comprises the steps
of:
[0011] A. positioning a distal end of a cannula within the heart
vessel;
[0012] B. conducting a flow of pressurized cardioplegia through an
infusion lumen of the cannula and discharging the cardioplegia into
the heart vessel;
[0013] C. communicating the infusion lumen with a balloon disposed
on the distal end to cause the cardioplegia to inflate the balloon
into sealing contact with a wall of the heart vessel during step
B;
[0014] D. halting the flow of cardioplegia through the infusion
lumen while preventing drainage of cardioplegia from the balloon,
to maintain the balloon in its inflated state; and
[0015] E. thereafter repeating step B.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The objects and advantages of the invention will become
apparent from the following detailed description of preferred
embodiments thereof in connection with the accompanying drawings in
which like numerals designate like elements and in which:
[0017] FIG. 1 is a longitudinal sectional view through a cannula
according to a first embodiment of the present invention, with a
valve in an open position.
[0018] FIG. 2 is a view similar to FIG. 1 with the valve in a
closed position.
[0019] FIG. 2A is a cross sectional view taken along the line 2A-2A
in FIG. 2.
[0020] FIG. 2B is a cross sectional view taken along the line 2B-2B
in FIG. 2.
[0021] FIG. 3 is a longitudinal sectional view taken through a
cannula according to a second embodiment of the present
invention.
[0022] FIG. 3A is a cross-sectional view taken along the line 3A-3A
in FIG. 3, showing a valve in a closed position.
[0023] FIG. 3B is a view taken along the line 3A-3A in FIG. 3 with
the valve in an open position.
[0024] FIG. 4 is a longitudinal sectional view through a third
embodiment of the invention, with a valve in a closed position.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION
[0025] Depicted in FIGS. 1-2B is a retrograde cannula 10 having an
automatically inflatable balloon adjacent its distal end. The
cannula 10 includes a body 14 formed of a flexible plastic material
suitable for insertion into a human body, such as PVC, urethane or
silicone. Extending generally centrally through the body is an
infusion lumen 16 capable of conducting a fluid, such as
cardioplegia (CPG) from a proximal end of the cannula to one or
more outlet openings 20 formed adjacent a distal end of the
cannula. The outlet opening(s) may comprise forwardly-facing
openings or side-facing openings.
[0026] Also formed in the cannula body 14 are a control lumen 22
and a pressure monitoring lumen 24 extending parallel to the
infusion lumen. The pressure monitoring lumen 24 includes an
opening 26 at its distal end for communicating with the interior of
a vessel into which the cannula is to be inserted. The pressure
monitoring lumen 24 serves as a pressure lumen to enable pressure
in the vessel to be monitored.
[0027] Surrounding the body 14 adjacent the distal end thereof is
the balloon 12. The balloon is secured to the body (or formed
integrally with the body) in a conventional way and can be of
conventional design. A passage arrangement formed by at least one,
but preferably more than one, communication passages 30 places the
balloon in fluid communication with the infusion lumen 16.
[0028] Preferably, the balloon is of the type that permanently
assumes a predetermined shape and size whether inflated or not, and
becomes stiff or turgid when inflated (in contrast to the type of
balloon normally used in manual inflate cannulas that can contract
into tight contact with the body when deflated).
[0029] The communication passages 30 are oriented to extend through
the control lumen 22, as can be seen in FIG. 1. Moreover, a width
W1 of the control lumen 22 is greater than a width W2 (e.g.,
diameter) of each communication passage. Disposed in the control
lumen is a valve in the form of a slidable rod 34 having a width
greater than that of each of the communication passages 30.
Therefore, when the rod is slid forwardly toward the distal end of
the body 14 (i.e., to the left in FIG. 1), so that the rod travels
past the communication passages 30, the communication passages 30
will become closed. Thus, the rod is movable between an open
position (FIG. 1) for opening the passages 30, and a closed
position (FIG. 2) for closing the passages.
[0030] In order to ensure against leakage through the control lumen
22 when the rod 34 is in the open position (i.e., leakage to the
right in FIG. 2), the rod 34 can be provided with a flexible seal
element 36 which forms a seal against the wall of the control
lumen.
[0031] In typical practice, the cannula 10 is inserted into a
patient's body during cardiac surgery such that the distal end
enters the coronary sinus. This is preferably performed with the
aid of a stiff stylus (not shown) that has been temporarily
inserted into the infusion lumen 16. Once the cannula has reached
the desired position the stylus is removed and a suture ring (see
the suture ring 40 shown in FIG. 3) of the cannula is sutured to
the heart. With the rod 34 in its open position (FIG. 2),
cardioplegia (CPG) is conducted under pressure through the infusion
lumen 16, the CPG exiting the cannula through the discharge
openings 20. Simultaneously, the CPG enters the balloon through the
communication openings 30 and inflates the balloon into sealing
relationship with the wall of the coronary sinus. Accordingly, the
CPG is introduced into a cardiac sinus vessel, producing cardiac
arrest. Then, the rod 34 is slid forwardly to the closed position
(FIG. 1) to block the communication passages 30, and the flow of
CPG through the infusion lumen is then temporarily halted.
[0032] Since the passages 30 are blocked, the balloon 12 remains
firmly biased against the wall of the coronary sinus, to resist
shifting of the distal end of the cannula. Accordingly, when the
flow of CPG is resumed, the distal end of the cannula will still be
disposed in the desired position.
[0033] Eventually, when the cannula is no longer needed, the
balloon is deflated to enable it to be removed. That could be
accomplished by moving the rod 34 to its open position to cause the
cardioplegia in the balloon to flow back into the infusion lumen
16. Alternatively, a separate drain lumen could be provided for
interconnecting the balloon and the infusion lumen, similar to the
structure 52, 59 which will be described later in connection with
FIGS. 3-3B.
[0034] It will be appreciated that the shape of the control lumen
22 and the rod 34 may vary as long as the rod is able to close the
passages 30.
[0035] A second preferred embodiment of a cannula 10A is depicted
in FIGS. 3-3B. In that embodiment, the control lumen and the rod
are eliminated. Instead, the valve is in the form of an elastic
membrane 50 which covers the communication passages 30A. The
membrane 50 extends completely around the infusion lumen in the
form of a band or sleeve formed of a suitable elastic plastic
material. When CPG is conducted through the infusion lumen 16A, the
pressurized CPG will force the sleeve 50 away from the passages 30
(i.e., to an open position) as shown in FIG. 3B, to enable the
balloon 12A to be inflated. When the flow of CPG is halted, the
sleeve will elastically rebound into tight contact with the wall of
the lumen 16A to seal the passages 30 (as shown in FIG. 3A) and
prevent the balloon from being deflated. Thus, the valve 50 opens
and closes automatically, in contrast to the earlier disclosed
valve 34 which is opened and closed manually.
[0036] When it is desired to remove the cannula 10A from the heart,
the balloon is deflated by draining the CPG therefrom. That is
achieved by a drain lumen 52 formed in the cannula body 14A. A
distal end of the drain lumen 52 is closed off by a plug 54, and a
proximal end 56 of the drain lumen communicates with the infusion
lumen 16A. A drain hole 58 formed in the drain lumen communicates
with the balloon interior, and a manually actuable valve 59
controls the drainage of the CPG from the balloon. The valve 59 can
be of any suitable type, such as a stop-cock or tubing clamp for
example. With the balloon in an inflated state, an opening of the
drainage valve 59 will cause the balloon to deflate, with the
draining CPG re-entering the infusion lumen 16A. Note also that the
valve could be in the form of an external clamp, such as a hemostat
or a tube or clamp, which blocks the escape of fluid from the
balloon along the control lumen.
[0037] A third preferred embodiment of a cannula 10B is disclosed
in connection with FIG. 4 and is similar to that of FIG. 3, except
that the proximal end of the drain lumen 52B does not communicate
with the infusion lumen. Note that in this cannula 10B, the removal
of CPG from the drain lumen 52B, could be performed by forming the
closure as a valve that can be opened. Alternatively, instead of
allowing the CPG to drain freely through an opened valve, the CPG
could be actively drained by being sucked through the drain lumen
52B using a suitable suction device, such as a syringe. In that
event, the closure 59 could be in the form of a self-sealing plug
through which the needle of the syringe could be inserted to
withdraw fluid from the balloon. As a further alternative, the
closure could comprise a syringe activated valve which would be
used in conjunction with a syringe to withdraw fluid from the
balloon. The withdrawal of CPG by a suction is particularly
advantageous, because the suction can pull the balloon tightly
against the body of the cannula, thereby reducing the profile of
the cannula to facilitate passage thereof through the patient's
body during insertion as well as removal of the cannula.
[0038] It will be appreciated that the present invention provides a
way of preventing the auto-inflate balloon of a retrograde cannula
from deflating between deliveries of CPL while the cannula remains
in a patient's body, thereby keeping the distal end of the cannula
in a desired state.
[0039] It will also be appreciated that numerous other types of
manually or automatically operated valves could be employed in
carrying out the invention, the ones disclosed herein merely being
preferred.
[0040] Although the present invention has been described in
connection with preferred embodiments thereof, it will be
appreciated by those skilled in the art that additions,
modifications, substitutions and deletions not specifically
described may be made without departing from the spirit and scope
of the invention as defined in the appended claims.
* * * * *