U.S. patent application number 09/345892 was filed with the patent office on 2002-02-07 for anti-clotting methods and apparatus for indwelling catheter tubes.
Invention is credited to MOOREHEAD, H. ROBERT, WISE, MARCIA A..
Application Number | 20020016584 09/345892 |
Document ID | / |
Family ID | 23356970 |
Filed Date | 2002-02-07 |
United States Patent
Application |
20020016584 |
Kind Code |
A1 |
WISE, MARCIA A. ; et
al. |
February 7, 2002 |
ANTI-CLOTTING METHODS AND APPARATUS FOR INDWELLING CATHETER
TUBES
Abstract
Enabled or activated closure and sealing devices in the form of
closure balloons, and related methods, are disclosed, which
substantially preclude entry and clotting of blood at the distal
end of a lumen of an indwelling catheter tube during times when
flow therein is not occurring. The closure and sealing balloon is
disabled or deactivated to accommodate flow, without clotting,
through the lumen of the catheter tube when flow therein is
resumed.
Inventors: |
WISE, MARCIA A.; (DRAPER,
UT) ; MOOREHEAD, H. ROBERT; (SALT LAKE CITY,
UT) |
Correspondence
Address: |
LYNN G FOSTER
L GRANT FOSTER
FOSTER & FOSTER LC
602 EAST 300 SOUTH
SALT LAKE CITY
UT
84102
|
Family ID: |
23356970 |
Appl. No.: |
09/345892 |
Filed: |
July 1, 1999 |
Current U.S.
Class: |
604/509 |
Current CPC
Class: |
A61M 25/10 20130101;
A61M 25/0032 20130101; A61M 2025/0018 20130101; A61M 25/0028
20130101; A61M 2025/0079 20130101; A61M 25/003 20130101; A61M
2025/0031 20130101 |
Class at
Publication: |
604/509 |
International
Class: |
A61M 005/00; A61M
005/14; A61M 031/00 |
Claims
What is claimed and desired to be secured by Letters Patent is:
1. A method of addressing the problem of clotting in an idle
catheter tube indwelling within a vessel of a medical patient
comprising the acts of: advancing a deflated balloon along a hollow
interior of the idle indwelling catheter tube to a distal end
thereof; inflating the balloon to close and seal the hollow
interior at the distal end of the idle indwelling catheter tube to
deny blood access to the hollow interior.
2. A method according to claim 1 further comprising the act of
purging the hollow interior of the catheter tube in a
proximal-to-distal direction with a suitable liquid under
pressure.
3. A method according to claim 2 wherein the purging act precedes
the inflating act.
4. A method according to claim 2 wherein the purging act follows
the inflating act, the pressure of the liquid temporarily unsealing
the inflated balloon.
5. A method according to claim 2 wherein the purging act takes
place across a slit valve.
6. A method according to claim 1 further comprising the acts of
deflating the balloon and causing flow through the hollow interior
of the catheter tube.
7. A method according to claim 6 further comprising the act of
withdrawing the balloon after the deflating act and before the
causing act.
8. A method according to claim 6 wherein the deflating act takes
place across a slit valve.
9. A method according to claim 1 wherein the inflating act takes
place across a slit valve.
10. A method of addressing the problem of clotting in idle ingress
and egress companion catheter tubes indwelling within a vessel of a
medical patient, comprising the acts of: advancing a deflated
balloon along a hollow interior of each idle ingress and egress
catheter tube to a distal end of each; inflating the respective
balloons to close and seal the hollow interior at the distal end of
each catheter tube, thereby denying blood access to the hollow
interior of each.
11. A method according to claim 10 further comprising the act of
purging the hollow interior of one or both catheter tubes in a
proximal-to-distal direction with a suitable liquid under
pressure.
12. A method according to claim 11 wherein the purging act precedes
the inflating act.
13. A method according to claim 11 wherein the purging act follows
the inflating act, the pressure of the liquid temporarily unsealing
the inflated balloon.
14. A method according to claim 10 wherein the purging act takes
place across a slit valve.
15. A method according to claim 10 further comprising the acts of
deflating both balloons and causing ingress and egress flow through
the respective hollow interiors of the catheter tubes.
16. A method according to claim 15 further comprising the act of
withdrawing the balloon after the deflating act and before the
causing act.
17. A method according to claim 15 wherein the deflating act takes
place across a slit valve.
18. A method according to claim 10 wherein the inflating act takes
place across a slit valve.
19. A method of addressing the problem of clotting in a catheter
tube indwelling within a vessel of a patient comprising the acts
of: terminating flow along a hollow interior passageway of the
indwelling catheter tube; after the terminating act, inflating a
balloon to close and seal the hollow interior passageway at a
distal end of the indwelling catheter tube to deny blood in the
vessel access to the hollow interior.
20. A method according to claim 19 further comprising the act of
purging the hollow interior of the catheter tube in a
proximal-to-distal direction with a suitable liquid under
pressure.
21. A method according to claim 20 wherein the purging act precedes
the inflating act.
22. A method according to claim 20 wherein the purging act follows
the inflating act, the pressure of the liquid temporarily unsealing
the inflated balloon.
23. A method according to claim 20 wherein the purging act takes
place across a slit valve.
24. A method according to claim 19 further comprising the acts of
deflating the balloon and causing flow through the hollow interior
passageway of the catheter tube.
25. A method according to claim 19 further comprising the act of
withdrawing the balloon after the deflating act and before the
causing act.
26. A method according to claim 24 wherein the deflating act takes
place across a slit valve.
27. A method according to claim 19 wherein the inflating act takes
place across a slit valve.
28. A method of addressing the problem of clotting in ingress and
egress companion catheter tubes indwelling within a vessel of a
medical patient, comprising the acts of: terminating ingress and
egress flow along hollow interior passageways of the indwelling
catheter tubes, respectively; after the terminating step, inflating
balloons to close and seal the respective hollow interior
passageways at the distal ends of the indwelling ingress and egress
catheter tubes to deny blood in the vessel access to the hollow
interior passageways.
29. A method according to claim 28 further comprising the act of
purging one or both hollow interior passageways in a
proximal-to-distal direction with a suitable liquid under
pressure.
30. A method according to claim 29 wherein the purging step
precedes the inflating step.
31. A method according to claim 27 wherein the purging step follows
the inflating step, the pressure of the liquid temporarily
unsealing the inflated balloon.
32. A method according to claim 29 wherein the purging act takes
place across a slit valve.
33. A method according to claim 28 further comprising the acts of
deflating the balloons and causing ingress and egress flow through
the hollow interior passageways, respectively.
34. A method according to claim 33 wherein the deflating act takes
place across a slit valve.
35. A method according to claim 28 wherein the inflating act takes
place across a slit valve.
36. In combination, a catheter tube for selective flow through a
hollow passageway of the catheter tube to or from a patient and a
balloon selectively inflated to close and seal the hollow
passageway at a distal end of the catheter tube against entry of
blood when flow is not occurring through the hollow passageway.
37. A combination according to claim 36 wherein the balloon is
carried near a distal end of an inflation/deflation stem extending
within the hollow passageway for substantially the full length of
the catheter tube.
38. A combination according to claim 37 wherein the stem carries
distance indicia for locating the balloon at the distal end of the
catheter tube.
39. A combination according to claim 37 wherein a seal is
interposed between the catheter tube and the stem within the hollow
passageway at a proximal end of the catheter tube, the stem being
selectively displaceable along the hollow passageway through a
central opening in the seal.
40. A combination according to claim 39 wherein the seal is
selectively compressed by a control to clamp against the stem to
prevent stem displacement.
41. A combination according to claim 36 wherein the balloon is
carried by the catheter tube within the hollow passageway at the
distal end of the catheter tube.
42. A combination according to claim 36 wherein the balloon
comprises a weak portion of a wall of the catheter tube.
43. A combination according to claim 41 further comprising a
pathway along the catheter tube by which fluid under pressure is
delivered to and removed from the balloon to selectively inflate
and deflate the balloon.
44. A combination according to claim 36 further comprising a port
adjacent the proximal end of the catheter tube by which a flushing
liquid under pressure is selectively displaced proximal-to-distal
within the hollow passageway of the catheter tube.
45. In combination, companion ingress and egress catheter tubes for
selective flow through a hollow passageway in each catheter tube
respectively to and from the patient and a balloon associated with
each catheter to accommodating selective inflation of the balloons
to generally concurrently close and seal the two hollow passageways
at respective distal ends of the ingress and egress catheter tubes
against entry of blood from a vessel of the patient when flow is
not occurring through the hollow passageways.
46. A combination according to claim 45 wherein the balloons are
carried near distal ends of spaced inflation/deflation stems
extending respectively within the hollow passageways for
substantially the full length of the respective catheter tubes.
47. A combination according to claim 46 wherein a seal is
interposed between each catheter tube and the associated stem
within the hollow passageway of said catheter tube at a proximal
end of said catheter tube, each stem being selectively displaceable
through a central opening within the associated seal.
48. A combination according to claim 47 wherein each seal is
selectively compressed by a control to clamp against the associated
stem to prevent stem displacement.
49. A combination according to claim 45 wherein each balloon is
carried by the associated catheter tube within the hollow
passageway at the distal end thereof.
50. A combination according to claim 47 further comprising a
pathway along each catheter tube by which fluid under pressure is
delivered to the associated balloon to selectively inflate and
deflate the associated balloon.
51. A combination according to claim 45 further comprising a port
near the proximal end of each catheter tube by which a flushing
liquid under pressure is selectively displaced proximal-to-distal
within the hollow passageways of the catheter tubes.
52. A method of addressing the problem of clotting in an idle
catheter tube placed within a vessel of a medical patient
comprising the acts of: advancing a deflated balloon along a hollow
interior of the idle catheter tube to a distal end thereof prior to
placement of the catheter tube in the vessel; inflating the balloon
to close and seal the hollow interior at the distal end of the
catheter tube; collectively introducing the distal end of the
catheter tube and the inflated balloon into the vessel.
53. A method according to claim 52 further comprising the acts of
deflating the indwelling balloon and accommodating liquid flow
through the catheter tube.
54. A method of addressing the problem of clotting in idle ingress
and egress companion catheter tubes placed within a vessel of a
medical patient, comprising the acts of: advancing a deflated
balloon along a hollow interior of each idle ingress and egress
catheter tube to a distal end of each prior to placement of either
catheter tube in the vessel; inflating the respective balloons to
close and seal the hollow interior at the distal end of each
catheter tube; introducing each inflated balloon and the distal end
of the associated catheter tube together into the vessel.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to catheter tubes
and more specifically to anti-clotting methods and apparatus for
catheter tubes.
BACKGROUND
[0002] Typically, for example only, many dialysis medical patients
are treated for a few hours every two or three days. Dialysis is
performed by removing blood from the patient through an effluent or
egress catheter tube, processing the removed blood through an
artificial kidney machine to filter impurities from the blood, and
returning the cleansed or processed blood to the patient through an
influent, infusion or ingress catheter tube. The two catheter tubes
may be any of several configurations, including but not limited to
two essentially separate catheter tubes, a dual lumen catheter or
any other suitable egress/ingress arrangement.
[0003] It is desirable to limit the number of times a vessel of the
patient is penetrated for placement therein of dialysis catheter
tubes. Accordingly, once placed, it is desirable for the distal end
of the egress and ingress catheter tubes to be left indwelling for
an extended period of time to accommodate spaced, repeated
dialysis. Accordingly, the indwelling egress and ingress catheter
tubes are inactive typically for much longer intervals than they
are active. In addition, catheter tubes for other purposes are
sometimes left indwelling for long periods of time and are
frequently idle with no flow therethrough. This includes, but is
not limited to, the central venous catheter category.
[0004] During idle times, when flow is not occurring in a given
indwelling catheter tube, blood tends to enter the distal opening
of the indwelling catheter tube. This is true even when the lumen
of the catheter tube is full of liquid, other than blood, such as
saline or heparin. During these idle times, blood flow through the
vessel around the outside of the catheter tube tends to evacuate
liquid from the lumen at the distal tip of the idle indwelling
catheter tube, which is replaced by blood. This blood in the distal
tip of each catheter tube tends to remain stationary, risking the
development of a clot.
[0005] When clotting occurs within the lumen at the distal end of a
catheter tube, an expensive clot-busting medication, such as
Urokinase, is introduced into the proximal end of the catheter
tube. After a suitable waiting period, during which the clot is
softened, the medication and softened clot are aspirated from the
catheter tube through the proximal end thereof. Where sufficient
softening does not occur, the expensive clot-busting medication
process may be repeated. Sometimes the clot is discharged into the
vessel from the lumen using a liquid under positive pressure, which
creates undesired risks for the patient. If all else fails, the
catheter tube with the clot therein is removed from the patient at
the vessel puncture site and a new replacement catheter tube
inserted into the vessel.
[0006] Given the foregoing, provision of reliable and inexpensive
methods and apparatus for avoiding or greatly alleviating clotting
in indwelling catheter tubes would solve a long standing medical
problem.
BRIEF SUMMARY AND OBJECTS OF THE PRESENT INVENTION
[0007] In brief summary, the present invention overcomes or
substantially alleviates clotting problems heretofore associated
with certain types of catheter tubes. The present invention
utilizes an enabled or activated closure and sealing device and
related methods to substantially preclude entry and clotting of
blood at the distal end of a lumen of an indwelling catheter tube
during times when flow therein is not occurring. The closure and
sealing device is disabled or deactivated to accommodate flow,
without clotting, through the lumen of the catheter tube when flow
therein is initiated or resumed. In a presently preferred form, the
closure device may comprise an inflatable/deflatable balloon,
which, when inflated, closes the lumen of the catheter tube at the
distal end thereof. The invention can be configured to accommodate
flushing or purging of the lumen of the indwelling catheter tube
either before or after inflated deployment of the balloon closure.
The balloon mechanism may be inserted into the patient as the
catheter tube is inserted, with the balloon either inflated or
deflated, or separately after the catheter tube is first inserted.
The invention applies to trimmable and non-trimmable catheters. The
balloon may be a separate component or integrated with the catheter
tube. Slit valve mechanisms may be used to control flow through the
lumen of the catheter tube, to prevent or alleviate leakage at the
proximal end of the catheter tube, and to control fluid flow to and
from the balloon.
[0008] In view of the foregoing, it is a primary object of the
present invention to overcome or materially alleviate clotting
problems heretofore associated with certain types of catheter
tubes.
[0009] Another important object is the provision of anti-clotting
methods and apparatus for indwelling catheter tubes.
[0010] A further paramount object is the utilization of a closure
and sealing device and related methods which, when the device is
activated, substantially precludes entry and clotting of blood at
the distal end of a lumen of an indwelling catheter tube during
times when flow therein is not occurring and/or when the catheter
tube and balloon are collectively introduced into the vessel.
[0011] Another dominant object is the provision of a closure and
sealing device and related methods, which device can be activated
to preclude entry and clotting of blood within a lumen of a
catheter tube during introduction and/or during times when flow
therein is not occurring and can be deactivated to accommodate flow
through the lumen of the catheter tube.
[0012] It is another valuable object of the present invention to
provide an inflatable/deflatable balloon device for selective
closure of a lumen of a catheter tube at the distal end thereof,
when inflated.
[0013] An additional significant object is the provision of a
trimmable or non-trimmable catheter tube in combination with a
balloon closure device at the distal end of the catheter tube which
accommodates use of a liquid under pressure to flush or purge the
lumen of the indwelling catheter tube, either before or after
inflated deployment of the balloon closure.
[0014] A further valued object is the provision of novel balloon
closures in combination with the distal ends of catheter tubes
wherein a slit valve mechanism is used to control flow through the
lumen of an associated catheter tube, to prevent or alleviate
leakage at the proximal end of the catheter tube, and/or to control
fluid flow to and from the balloon.
[0015] These and other objects and features of the present
invention will be apparent from the detailed description taken with
reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIGS. 1 and 2 are elevational views partly in cross section
of the prior art dialysis catheter tubes, illustrating blood clots
within the lumen of each tube at the distal end thereof;
[0017] FIG. 3 is an elevational view partly in cross section of one
configuration of the present invention comprising a balloon end
closure sealing the lumen of a catheter tube at the distal end
thereof;
[0018] FIG. 4 is an enlarged fragmentary view partly in cross
section of the balloon closure of FIG. 3 unsealed from the interior
wall of the catheter tube by flushing or purging liquid under
pressure;
[0019] FIG. 5 is a view similar to FIG. 4 showing the balloon
closure resealed after displacement of purging liquid under
pressure is discontinued;
[0020] FIGS. 6, 7 and 8 are elevational views partly in cross
section of balloon closure in combination with various catheter
tubes;
[0021] FIG. 9 is a plan view illustrating structure by which (1)
flushing liquid under pressure is displaced through the lumen of a
catheter tube and (2) fluid is displaced to inflate and deflate a
balloon closure at the distal end of the catheter tube;
[0022] FIG. 10 is an enlarged exploded fragmentary plan view partly
in cross section of the assembly at the proximal end of the
catheter tube of FIG. 9;
[0023] FIGS. 11 and 12 are enlarged fragmentary cross sections of a
seal and clamp arrangement at the proximal end of the catheter tube
of FIG. 9 through which a stem for inflating a balloon closure
passes in sealed and clamped relationships respectively, the stem
having distance indicia by which the balloon closure is accurately
located inside the lumen at the distal end of the catheter
tube;
[0024] FIG. 13 is an enlarged cross section of the distal end of a
catheter tube equipped with an integrated balloon closure;
[0025] FIG. 14 is an enlarged fragmentary cross section of the
distal end of a catheter tube equipped with another form of
integrated balloon closure;
[0026] FIG. 15 is a cross section taken along lines 15-15 of FIG.
14;
[0027] FIG. 16 is a fragmentary diagrammatic illustration of a slit
valve mechanism used to control inflation and deflation of a
balloon closure at the distal end of a catheter tube; and
[0028] FIG. 17 is a fragmentary diagrammatic illustration of a slit
valve mechanism used to control purging of the lumen of a catheter
tube.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS
[0029] Reference is now made in detail to the drawings wherein like
numerals are used to designate like parts throughout. In reference
to FIGS. 1 and 2, which relate to a problem associated with the
prior art. Specifically, catheters of various kinds, including but
not limited to central venous catheters and dialysis catheters are
idle for substantial intervals of time. That is to say, flow of
liquid through catheter tubes of the type mentioned, is
discontinued for extended periods of time and thereafter resumed.
In the case of dialysis, blood is removed from the patient through
an effluent or egress catheter lumen 20 and is processed through an
artificial kidney machine to filter impurities from the blood. The
processed blood is then returned to the vessel through an ingress
catheter lumen 24. See FIGS. 1 and 2. In FIG. 1, the egress and
ingress lumens 20 and 24 comprise part of the dual lumen catheter,
generally designated 26, the dual lumen catheter 26 passing through
a venepuncture site 28, which penetrates through the skin 30,
tissue 32 and vessel wall 22 as such that the distal ends 34 and 36
of the dual lumen catheter tube comprising lumens 20 and 24 are
indwelling, while two proximal fittings or hubs 38 are outdwelling
and are illustrated as being closed, in each case, by a removable
stopper or plug 40.
[0030] In FIG. 2, side by side catheter tubes 42 and 44 pass
through a common venepuncture site 28', defining, respectively,
lumens 20 and 24. Catheter tubes 42 and 44 comprise distal ends 34
and 36, respectively. The exposed proximal ends 46 and 48 of the
catheter tubes 42 and 44 are respectively equipped with hubs 50 and
52, each of which is illustrated as being closed by a stopper or
plug 40. While not shown, sometimes a single lumen catheter is also
left indwelling for substantial intervals when flow is not
occurring through the lumen thereof. Because it is desirable to
limit the number of times a vessel of a patient is punctured or
penetrated for placement therein of one or more desired catheter
tubes, catheter tubes which are used only intermittently are
retained indwelling so long as there is sufficient medical reason
not to remove the same and replace them with other catheters.
[0031] During the interval of time when a catheter or a plurality
of catheters are left indwelling in a vessel, with no flow
occurring through the catheter or catheters, blood tends to enter
the distal end of each catheter tube, i.e., in the case of FIGS. 1
and 2 at the distal portions of lumens 20 and 24. This is true even
when the lumen or lumens are full of liquid, other than blood, such
as saline or heparin. During these idle times, blood flow through
the vessel around the outside of the catheter tube or tubes tends
to evacuate liquid from the lumen or lumens at the distal tip or
tips and to replace such evacuated liquid by blood. Because such
blood at the distal tip of a catheter lumen tends to remain
stationary, clots within the lumen or lumens can and sometimes do
develop. These clots are identified by the numeral 54 in FIGS. 1
and 2.
[0032] When clotting occurs within a lumen at the distal end of a
catheter tube, an expensive clot-busting medication, such as
Urokinase, is sometimes introduced into the proximal end of the
catheter tube. After a suitable waiting period, during which the
clot is softened, the medication and softened clot are aspirated
from the catheter tube through the proximal end thereof. When
sufficient softening does not occur, the expensive clot-busting
medication process may be repeated. Sometimes the clot is
discharged into the vessel from the lumen using a liquid under
positive pressure, which creates undesired risks for the patient.
If all else fails, the catheter tube with the clot therein is
removed from the patient at the vessel puncture site and a new
replacement catheter is inserted into the vessel.
[0033] Given the foregoing, it should be clear that avoidance of a
clot at the distal end of an indwelling catheter tube would be a
far better solution than trying to deal with a clot once it has
developed. The present invention overcomes or substantially
alleviates clotting problems heretofore associated with certain
types of catheter tubes. One embodiment of the present invention is
illustrated in FIG. 3 and is generally designated as 60. The
catheter assembly 60 comprises a catheter tube 62, having a hollow
cylindrical wall 64 defining a lumen 66 therein. The distal end 67
of the catheter tube 62 is indwelling within vessel 22. The
outdwelling portion of the catheter tube 62 comprises a Y-adapter
68. One branch 69 of the adapter is connected to a source 70 of
saline which is or can be placed under pressure. The Y-adapter 69
can be part of the catheter, but in certain applications can
preferably be part of the balloon closure assembly as explained
hereinafter in greater detail.
[0034] The main, straight proximal end 71 of the Y-adapter at 68
connects to a proximal fitting or hub 72, which comprises an
internal seal through which a hollow stem 74 passes. Stem 74 is in
fluid communication with an internal balloon 76 and an external
indicator balloon 79. The stem 74 connects across a hollow fitting
77 which comprises a Luer fitting into which a syringe, generally
designated 80, is inserted. Syringe 80 comprises a barrel 82 and a
plunger 84. The amount of saline in the barrel 82 of the syringe is
that required to fully inflate the balloon 76. For example, saline
may be initially loaded into the barrel 82 of the syringe 80 and,
upon placement of the balloon 76, in deflated condition, at the
distal end 67 of the catheter tube 62, the plunger 84 is advanced
to discharge saline under pressure from the barrel 82 across the
Luer fitting 78, across hollow fitting 77, along hollow stem 74 to
inflate the balloon 76 into the configuration illustrated in FIG.
3. The Luer fitting 78, as is conventional, comprises a seal which
prevents leakage both when free of the syringe 80 and when
connected to the syringe. Likewise, the saline from source 70
inflates the indicator balloon 79. When balloon 79 is fully
inflated, the medical technician or other user knows the internal
balloon 76 is fully inflated. Furthermore, the indicator balloon 79
is constructed so that it will rupture due to excessive pressure
before the balloon 76 ruptures, to insure safety in use. Also,
after placement and before inflation of the balloon 76, saline or
other appropriate liquid may be displaced under pressure through
port 69 to purge passageway 66 of any undesired substances, such as
blood or other infusant that may have been used.
[0035] The balloon 76 and the catheter tube 62 are preserved in the
relationship illustrated in FIG. 3 until such time as it is desired
to resume flow through the catheter tube 62, in which case the
balloon 76 is deflated by aspirating saline from balloon 76 into
the barrel 82. The balloon 76, in a deflated condition, may be left
near the distal end 67 of the catheter tube 62 and infusion of a
suitable fluid through the- catheter is accomplished by connection
of the fluid source to the arm 69. In the alternative, the balloon
76 may be withdrawn from the catheter tube, which would entail
removal of the stop 72, the deflated balloon 76, the balloon stem
74, the fitting 77, the Luer fitting 78 and the syringe 80 and,
thereafter, connection of the proximal end of the main bore of the
catheter tube to other apparatus which accommodates liquid flow
through the lumen 66, in or out as appropriate.
[0036] With the balloon 76 inflated, as illustrated in FIG. 3,
blood is not permitted to back-flow into the lumen 66 and,
therefore, clotting within the distal end of lumen 66 is avoided.
Nevertheless, at one or more appropriate times, saline from source
70 may be delivered under pressure to the lumen 66 to purge the
lumen, which will temporarily dislodge and unseal the balloon 76
from the catheter tube 62, essentially as shown in FIG. 4. Once the
delivery of saline under pressure from source 70 is discontinued,
the balloon 76 will resume its closed, sealed and anti-clotting
position, as illustrated in FIG. 5.
[0037] When the anti-clotting embodiment shown and described in
connection with FIG. 3 is used on a dual lumen catheter assembly,
of the type illustrated in FIG. 1, two balloon mechanisms are used
of the type described in connection with FIG. 3, one for each lumen
20 and 24. This anti-clotting arrangement is illustrated in FIG. 7,
which is numerated consistent with the numerals used in FIGS. 1 and
3, so far as applicable.
[0038] Similarly, when two catheters are used, of the type shown in
FIG. 2, the anti-clotting embodiment of FIG. 3 may be combined
therewith in the manner illustrated in FIG. 8, which has been
enumerated so as to conform to the enumeration of FIGS. 2 and 3, so
far as applicable.
[0039] In reference to FIG. 6, it is understood by those skilled in
the art that some catheters, including catheter tube 80, comprise
not only a distal end opening 82, but one or more side ports 84. To
prevent entry of blood through one or more ports 84 during times
when the catheter tube 80 is not being actively used, an elongated
balloon 76' is provided so that, when inflated, the balloon 76' not
only closes and seals the catheter tube lumen 86 adjacent the
distal end 88 of the catheter tube 80, but also closes each side
port 84 to prevent entry of blood therethrough.
[0040] It is to be understood that the present invention applies to
trimmable catheters including but not limited to peripherally
inserted central catheters (PICC) and to tunnel catheters. These
catheters are characterized as being trimmable because the length
thereof is custom sized to the anatomy of a specific patient to
equal the distance between the entry site and the desired location
of the distal end of the catheter tube. Typically, this desired
length or distance is measured with a ruler along but outside the
patient. The measured distance is transferred to the catheter tube
and the catheter tube is cut (trimmed) to the desired length.
[0041] After the catheter tube is so trimmed, the present invention
may be implemented by inserting balloon closure (obturator) and
stem into the catheter tube while outside the body. The distal end
of the balloon closure is placed adjacent to the distal end of the
catheter tube and locked in this position. Then the catheter tube
and balloon with stem may be simultaneously inserted into a vessel
of the patient until the distal end of the catheter tube is
correctly positioned in the patient.
[0042] In the alternative, the locked stem, with proximal hub and
balloon may be removed from the catheter tube while it is external
of the patient and the catheter tube by itself inserted through a
puncture site into the vessel and advanced until the distal end
thereof is correctly positioned in the patient. Thereafter the
balloon and stem may be inserted into the indwelling catheter tube
until the hub associated with the stem is seated as sealed within
the hub or proximal fitting of the catheter tube, which will
correctly position the balloon adjacent to the distal end of the
catheter tube.
[0043] Blood leakage through the proximal fitting of the catheter
may be prevented by use of a slit valve within the proximal
fitting, or minimized by manually collapsing the proximal portion
of the catheter tube or placement of the user's thumb over the
proximal end, so far as possible.
[0044] The present invention also applies to non-trimmable catheter
tubes as exemplarily explained herein.
[0045] From the foregoing, it is clear that the present invention
utilizes an enabled or activated closure and sealing device, and
practices related methods, to substantially preclude entry and
clotting of blood at the distal end of a lumen of an indwelling
catheter tube during times when flow through the catheter tube is
not occurring. The closure and sealing device is disabled or
deactivated to accommodate resumption of flow, without clotting,
through the lumen of the catheter tube. The closure device may
comprise an inflatable/deflatable balloon which, when inflated,
closes the lumen of the catheter tube at the distal end thereof.
The invention may be configured to accommodate flushing of the
lumen of the catheter tube either before or after inflated
deployment of the balloon closure.
[0046] With reference to FIGS. 9 through 12, a Touhy-Borst fitting
may be used in conjunction with the present invention to deliver
and remove saline under pressure to and from the balloon closure 76
and to deliver saline or other liquid under pressure through the
associated catheter tube to purge the interior thereof More
specifically, in reference to FIG. 9, the outdwelling trailing end
of a catheter tube 100 is illustrated, where the distal end of the
catheter tube 100 is indwelling within a vessel of a patient.
Within the catheter tube 100 is disposed the balloon inflating stem
74 described above. The catheter tube 100 merges with a female
proximal fitting or hub 102, which is connected in
liquid-communicating relation with a proximal fitting 104, the
interior of which comprises a hollow passageway. Fitting 104
comprises a distal male portion 106, which is press-fit into the
hub 102 and a proximal hollow tube 108. The distal end of the tube
108 terminates in threads 110. See FIG. 10.
[0047] Threads 110 are threaded into a distal female threaded
receptacle 112 of a hollow Tee piece, generally designated 114. The
Tee piece 114 comprises a proximal portion 116, which is hollow,
and a side port 118 and a hub 119, both of which are also hollow.
Liquid flow under pressure to purge the lumen of the catheter 100
is introduced via side port 118 and passes through the hollow
fitting 112, the hollow of tube 108, the hollow of fitting 104, the
hollow of tube 106 and the hollow of the hub 102 to the lumen of
the catheter tube 100. This may be done, for example, by placing
the distal tip of a syringe, generally designated 120, into
liquid-communicating relation with the hub or sealing Luer fitting
119 of port 118 with the barrel 122 of the syringe 120, when the
barrel 122 is full of a suitable solution, such as saline, and
advancing the plunger 124 to extrude or discharge the saline from
the barrel 122 under pressure along the path mentioned above. The
Luer fittings 78 and 119 may comprise a commercially available
Halkey-Roberts or equivalent valve which opens upon reception of
the distal end of the syringe 80 or 120 and which closes
automatically when the syringe is removed. Such valves are commonly
used on endotracheal tubes and Foley catheters.
[0048] Within the hollow interior 126 of the exteriorly threaded
proximal connector 116 is disposed an annular seal 128 of silicone
rubber or the like, which comprises a central bore or aperture 130,
a distal face 132, a proximal face 134 and an annular edge face
136. As can be seen best in FIGS. 11 and 12, the annular or
disc-shaped seal 128 is snugly positioned within the hollow 126,
with the distal face 132 continuously abutting shoulders 138 and
140.
[0049] As viewed in FIG. 11, the balloon stem 74 passes snugly but
moveably through the aperture or bore 130 in the seal 128. The stem
74 is illustrated as having distance indicia 142 disposed thereon
for accurate placement of the balloon at the distal end of the stem
74 directly adjacent the distal end of the catheter tube 100 while
the distal end is indwelling. While distance indicia 142 is
referenced to the distal internal balloon 76 and may extend from
the distal balloon 76 to the proximal region of the stem 74, in
most if not all applications marks 142 are needed only for an
appropriate length along a proximal portion of the stem 74
sufficient to allow proper placement of the balloon 76 at the
distal end of both trimmable and non-trimmable catheter tubes as
determined by those skilled in the art.
[0050] However, when a double wall cap 144 is threaded upon
proximal connector 116, an internal annular portion 146 compresses
the annular seal 128 at surface 134. The overall effect of the
compression caused by the internal annular portion 146 causes the
seal 128 to attempt to expand radially outwardly and radially
inwardly. This places sufficient pressure from the seal 128 upon
the exterior surface of the stem 74 passing through the seal 128 so
that the stem 74 can no longer be moved in either a forward or
reverse direction in respect to the seal 128. In other words, the
seal 128, responsive to the compaction caused by portion 146,
clamps against the stem 74 causing it to be held in a desired
position. In this way, the balloon at the distal end of the stem 74
is retained in its selected position directly adjacent the distal
tip of the catheter tube 100 to function as an anti-clotting
closure device which prohibits blood from entering into the distal
end of the catheter tube lumen. See FIG. 12.
[0051] In further reference to FIG. 9, there is illustrated a
second syringe, generally designated 150, which comprises a barrel
152 initially loaded with a liquid, such as saline. The syringe 150
also comprises a plunger 154. When the plunger 154 is advanced, the
liquid within the barrel 152 is discharged under pressure into and
along the hollow stem 74 to inflate the closure balloon at the
distal end of the catheter tube 100 to close and seal the distal
end of the catheter tube. Thus, the balloon is inflated. When the
plunger 154 is thereafter retracted, the liquid in the balloon is
aspirated along the hollow stem 74 into the barrel 150, thereby
deflating the balloon.
[0052] Reference is now made to FIG. 13, which illustrates a
catheter tube 160 equipped with an integral balloon closure device,
generally designated 162, for closing and sealing the distal end of
the catheter tube 160 to prevent entry of blood during periods when
flow is not occurring within the lumen 164 of the catheter tube,
thereby preventing clotting of the blood within the lumen 164. The
catheter tube 160 comprises a wall 166 which is illustrated as
having a uniform thickness throughout and uniform inside and
outside diameters as well. Within the wall 160 is defined a
passageway 168 through which a suitable fluid, such as saline
liquid, is displaced from and to a source 170. Source 170 may be a
syringe of satisfactory capacity.
[0053] The source 170 communicates through a fitting 172 to the
passageway 168 to inflate the balloon 162 and from the interior of
the balloon through the passageway 168 and the fitting 172 to the
source 170 to deflate the balloon 162. The balloon 162 comprises a
rounded bladder 174, the edges 176 of which are secured to and
sealed against shoulders 178, using a suitable bonding agent or the
like. Shoulders 178 form two of the three walls of an annular
groove 180 into which fluid under pressure is delivered to inflate
the bladder 174, displacing the bladder 174 from the solid line
position to the dotted line position shown in FIG. 13. When it is
desired to deflate the bladder 174, the source 170 applies a
negative or aspirating pressure to the fluid, evacuating the fluid
from the groove 180 and passageway 168 to the source 170. Thus, the
embodiment illustrated in FIG. 13 provides an integrated catheter
tube and distal end closure device version of the present
invention.
[0054] Reference is now made to FIGS. 14 and 15, which illustrate a
further catheter with integral balloon embodiment of the present
invention, generally designated 202. Catheter 202 comprises a
catheter tube 203 comprising a one piece wall 204. The wall 204 is
bifurcated at locations 206 (FIG. 15) to define a large central
lumen 208, through which blood or other liquid is intended to flow,
and a small eccentric lumen 210, through which saline, air or other
fluid under pressure is displaced to inflate and deflate a closure
balloon, as more fully explained hereinafter. The distal end of the
lumen 210 is closed by a plug 211 or other suitable structure.
[0055] A relatively thin membrane 212 spans internally between the
bifurcation points 206. A distal portion 214 of the membrane 212 is
preferably weakened or of reduced strength so that fluid under
pressure expands the weakened portion 214 of the membrane 212 from
the solid to the dotted position, as shown in FIG. 14 and 15. When
the fluid pressure is removed, the memory of the portion 214 causes
it to resume its solid line position, accommodating liquid flow
through the central lumen 208.
[0056] Weakening of the portion 214 may be in any known way, such
as chemical treatment, reduced thickness or the like.
[0057] By having a beveled distal edge 216, the catheter tube 204
provides very little space for blood to be introduced at the distal
end of the catheter tube 204, when the weakened balloon portion 214
is inflated into the dotted line position. See FIG. 14.
[0058] The foregoing description of apparatus and methods
emphasizes prevention of refluxing of blood into a catheter tube,
when not in use, and prevention of diffusion of blood along with
the contents within the catheter, also when not in use. Some
important aspects of this invention are summarized below.
[0059] Basically, a flexible tube or balloon stem with a Luer
fitting on the proximal end and a balloon on the distal end which
is normally in the shape of an inflated balloon is used. The
balloon may be deflated by attaching a syringe to the luer fitting
and aspirating the air or other fluid out of the balloon. The
balloon may be so collapsed sufficiently to advance the balloon and
tube or stem into the catheter tube until the balloon is at the
distal end of the catheter tube. The syringe can either be
disconnected and allow the balloon to resume its normal shape
(conforming to the shape of the central lumen of the catheter tube
into which it has been placed) or the syringe can be activated to
reintroduce the air or other fluid which had been previously
removed. Upon removal of the syringe, any excess air or fluid which
had been instilled in the system would be dispelled from the
balloon catheter through the luer fitting, at which time a cap may
be placed on the luer fitting.
[0060] In respect to one method of placing a balloon at the distal
tip of catheter tube, the balloon is advanced during placement
until it is known that the balloon is slightly beyond tip of
catheter tube, either by knowing the exact length of catheter tube
and observing the measurement marks inscribed on the stem or it
will be advanced until upon release of negative pressure in the
stem, which collapses the balloon, it is noted that there is no
resistance to movement of the balloon and stem. Without a syringe
or cap on the proximal end of the stem, the stem will be moved
outward (retrograde) until resistance is felt and with another
one-half centimeter or so outward movement the balloon will be in
the correct position in the catheter tube.
[0061] It is often desirable to use a locking mechanism such as a
Touhy Borst adapter to insure that the stem does not move once it
is in the desired position.
[0062] Reference is now made to FIG. 16, which illustrates a
further embodiment of the present invention by which saline or
other suitable fluid under pressure is discharged from and received
at source 190, which may be a syringe. The saline or the like flows
bi-directionally through the stem 74 to and from a balloon closure
at the indwelling distal end of a catheter tube to prevent entry of
blood into the tube and subsequent clotting thereof. Flow to the
balloon inflates the balloon, while flow from the balloon to the
source 190 deflates the balloon. FIG. 16 illustrates that a two-way
slit valve mechanism 192 is positioned along the length of the tube
74. The two-way slit valve mechanism comprises a slit valve which
is normally closed. Thus, a certain pressure differential to cross
the slit valve is necessary in order to cause inflating or
deflating fluid flow across the mechanism 192. Such slit valve
mechanisms are known in the medical field. See, for example, U.S.
Pat. Nos. 5,169,393, 5,201,722, and 5,205,834.
[0063] Likewise, in reference to FIG. 17, a catheter tube 194 may
comprise a side port 196 equipped with a slit valve mechanism 198
similar or identical to the slit valve mechanism 192 mentioned
above. Thus, saline or like liquid under pressure may be delivered
from source 200 to the slit valve mechanism 198. When a suitable
pressure differential threshold is reached, the slit valve within
the mechanism 198 opens and the liquid under pressure proceeds into
the lumen 195 of the catheter tube 194 to purge the interior of the
catheter tube 194, either before or after inflating of a balloon
closure at the distal end of the catheter tube for the purpose of
preventing clotting of blood at the distal end of the catheter
tube.
[0064] The invention may be embodied in other specific forms
without departing from the spirit of the central characteristics
thereof. The present embodiments therefore to be considered in all
respects as illustrative and not restrictive, the scope of the
invention being indicated by the appended claims rather than by the
foregoing description, and all changes which come within the
meaning and range of equivalency of the claims are therefore
intended to be embraced therein.
* * * * *