U.S. patent application number 12/193607 was filed with the patent office on 2009-02-19 for catheter for media injection.
Invention is credited to Jawahar M. Desai.
Application Number | 20090048511 12/193607 |
Document ID | / |
Family ID | 21962032 |
Filed Date | 2009-02-19 |
United States Patent
Application |
20090048511 |
Kind Code |
A1 |
Desai; Jawahar M. |
February 19, 2009 |
Catheter For Media Injection
Abstract
An improved endocardial catheter includes a plurality of
longitudinally extending openings adjacent intermediate portions at
its distal end. The catheter is actuable from a retracted or
collapsed mode, wherein the sealed openings are arranged around the
tubular catheter surface, to an expanded mode. The plurality of
longitudinal openings in the catheter wall enable radial expansion
of the tubular surface at the distal end so that intermediate
portions of the tubular catheter surface are moved to an operative
position radially outward from their position in the retracted
mode. In the expanded position, the intermediate portions form
wings around the distal end, revealing a cavity within the tubular
catheter for the release of contrast material or other fluid into
endocardial sites through the longitudinal openings.
Inventors: |
Desai; Jawahar M.;
(Roseville, CA) |
Correspondence
Address: |
DAVIS WRIGHT TREMAINE LLP - San Francisco
505 MONTGOMERY STREET, SUITE 800
SAN FRANCISCO
CA
94111
US
|
Family ID: |
21962032 |
Appl. No.: |
12/193607 |
Filed: |
August 18, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10764189 |
Jan 23, 2004 |
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12193607 |
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09550692 |
Apr 17, 2000 |
6701180 |
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10764189 |
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|
09049841 |
Mar 27, 1998 |
6052612 |
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09550692 |
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08476122 |
Jun 7, 1995 |
5857464 |
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09049841 |
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Current U.S.
Class: |
600/435 ;
604/247; 604/523 |
Current CPC
Class: |
A61M 25/0074 20130101;
A61M 25/0068 20130101; A61M 2025/0057 20130101; A61M 2025/0079
20130101; A61M 2025/0073 20130101; A61M 25/0043 20130101; A61M
25/0075 20130101; A61M 25/007 20130101; A61M 25/008 20130101; A61M
25/04 20130101 |
Class at
Publication: |
600/435 ;
604/523; 604/247 |
International
Class: |
A61M 25/14 20060101
A61M025/14; A61M 25/00 20060101 A61M025/00; A61B 6/00 20060101
A61B006/00 |
Claims
1. A catheter comprising; an elongated tubular member having a
proximal end and a distal end; said tubular member including a
passageway extending throughout the length of the tube and forming
a wall proximal and distal openings; a plurality of
circumferentially-spaced longitudinally extending slits through
said wall adjacent the distal end defining a plurality of
circumferentially-spaced longitudinally extending flexible
intermediate portions of said wall, said flexible intermediate
portions capable of forming a plurality of wings extending from
said tube to provide for the discharge of fluid from the passageway
out through said wall through the open slits defined between said
wings.
2. The catheter of claim 1 which is insertable over and includes a
guidewire within said passageway.
3. The catheter of claim 2 including a valve normally sealingly
closing said distal opening, said valve sealing around said
guidewire during the passage of said guidewire through said tube
and valve.
4. The catheter of claim 1 including a valve means for at least
partially closing said passageway at the distal end of said tube,
said valve means comprising a plurality of resilient flaps which
flex when acted on by the force of fluid pressure originating
within said passageway.
5. The catheter of claim 1 wherein said flexible intermediate
portions are normally positioned to form said wings.
6. The catheter of claim 1 further including an external, removable
cannula dimensioned to fit over and collapse said tube to its
maximum length and minimum width and to compress said wings until
they return to a retracted position with said slits in a closed
position.
7. The catheter of claim 1 including means for expanding said
intermediate portions away from said tube to provide lateral
openings for the discharge of fluid from the passageway.
8. The catheter of claim 1 further including at least one
restrictor within said passageway for resisting axial flow
thereby.
9. The catheter of claim 8 wherein said restrictors comprise at
least one protuberance on said wall within said passageway.
10. The catheter of claim 9 wherein said restrictors comprise a
plurality of spaced, annular ribs.
11. A catheter comprising; an elongated tubular member having a
proximal end and a distal end; said tubular member having a thin
wall defining a passageway extending throughout the length of the
tube and forming proximal and distal openings; a plurality of
circumferentially-spaced longitudinally extending slits through
said thin wall adjacent the distal end defining a plurality of
circumferentially-spaced longitudinally extending flexible
intermediate portions of said thin wall, adjacent said slits; said
flexible intermediate portions normally forming a plurality of
wings extending from said tube with open slits therebetween to
provide for the discharge of fluid from the passageway through said
open slits in said thin wall near said distal end; an external,
removable cannula dimensioned to fit over and collapse said tube to
its maximum length and minimum width and to compress said wings
until they return to a position with said slits in a closed
position.
12. The catheter of claim 11 which is insertable over and includes
a guidewire in said passageway.
13. The catheter of claim 12 including a valve normally sealingly
closing said distal end of said passageway, said valve adapted to
seal against passage of fluid from said passageway through said
distal opening during passage of said guidewire through said tube
and valve.
14. The catheter of claim 11 including a valve means for at least
partially closing said distal opening, said valve means comprised
of a plurality of resilient flaps which will flex when exposed to
the force of fluid pressure originating within said passageway.
15. The catheter of claim 11 further including at least one
restrictor within said passageway for resisting axial flow
thereby.
16. The catheter of claim 15 wherein said restrictors comprise at
least one protuberance on said wall within said passageway.
17. The catheter of claim 16 wherein said restrictors comprise a
plurality of spaced, annular ribs.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of application Ser. No.
10/764,189, filed on Jan. 23, 2004, which in turn is a continuation
of application Ser. No. 09/550,692, filed on Apr. 17, 2000, now
U.S. Pat. No. 6,701,180, which in turn is a continuation of
application Ser. No. 09/049,841, filed Mar. 27, 1998, now U.S. Pat.
No. 6,052,612, which in turn is a continuation of application Ser.
No. 08/476,122, filed Jun. 7, 1995, now U.S. Pat. No. 5,857,464,
which applications and patents are incorporated herein in their
entirety by this reference.
BACKGROUND OF THE INVENTION
[0002] This invention relates to medical devices, and in particular
to angiographic catheters. Angiographic catheters are long, narrow,
thin-walled tubes that are percutaneously inserted into the human
or animal vascular system for therapeutic or diagnostic purposes.
Most diagnostic catheters have a series of side-holes in varied
configurations near the distal end, as well as an open end-hole at
the distal end tip. The end-hole allows the catheter to be passed
over and guided by a wire which has been inserted into the vascular
system through a hollow cannula placed in a blood vessel, after
which the guide wire is withdrawn. The smaller side-holes and
end-hole allows injection of radiopaque contrast material into the
blood stream surrounding the distal end, so as to produce an image
of the outline of a chamber or a blood vessel (an angiogram) on
X-ray film or other graphic medium. During the diagnostic
angiography process, the contrast material is normally injected at
a rapid rate using a power injector. The contrast material is
forcefully discharged from the end-hole and side-holes at the
distal end of the catheter.
[0003] Problems with forceful discharge of contrast material
through the end-hole and smaller side-holes of an angiographic
catheter are manifest. Forceful discharge can create a jet effect.
The end-hole jet effect produces undesirable recoil of the
catheter, thereby shifting the catheter from a desired position
within a chamber or a vessel, e.g. aortic root. Catheter jets can
also produce a dangerous complication, subintimal injection of the
contrast material, in which the jets tunnel into the wall of the
blood vessel, sometimes resulting in acute occlusion of the vessel
and in a chamber like left ventricle can cause subintimal injection
resulting in significant damage to endothelium. When dye is
injected in a chamber like left ventricle, an end-hole or side-hole
jet can also cause premature ventricular contractions (PVCs),
ventricular tachycardias (groups of three or more PVCs) and other
arrhythmias which endanger the patient, lengthen the time of
exposure to X-rays required for satisfactory opacification, and
often result in unintelligible chamber opacification in an
angiogram made during their occurrence.
[0004] A further complication resulting from pressurized discharge
of contrast material through the end and side-holes of known
catheters is the need for more contrast material than is optimally
desired to produce the angiogram. Available angiographic catheters
require as much as 50 to 55 milliliters (ml) of contrast material
to satisfactorily outline a human ventricle. Currently available
contrast material can cause undesirable generalized allergic
reactions like anaphylaxis and renal failure. Also, the amount of
material used dictates the time required to inject the material
and, therefore, affects both the required length of exposure to
dangerous X-rays as well as the probability of obtaining a
satisfactory angiogram. There is, therefore, a need in the field to
reduce the amount of contrast material used in cardiac
angiography.
[0005] Most catheters presently used for rapid flush angiography
are configured with a circular loop or "pigtail" at the distal end.
These pigtail-type catheters are provided with a plurality of
side-holes through which only approximately 40% of the contrast
medium is discharged at the desired position within the chamber.
Although the looped end of the catheter decreases somewhat the
chance of subintimal injection, the open end-hole still allows
approximately 40% of the contrast material to exit the end-hole.
The material exiting the end-hole creates a strong jet of material
placed away from the optimal position for vessel or chamber
opacification. To overcome the limitations of the pigtail catheter
in cardiac angiography, various modifications have been attempted
to the pigtail configuration, such as a bend at an acute angle in
the distal portion of the catheter and adding multiple holes on the
shaft, both to decrease the jet effect. However, these
modifications have not satisfactorily alleviated the problems
associated with the use of any catheter which has an open
end-hole.
[0006] The smaller side-holes located adjacent the distal end of
known angiographic catheters are flawed as well. Such side-holes
allow a very limited volume of material to form the bolus needed
for opacification of the chamber, thereby elongating the time
needed to adequately outline the chamber in the angiogram. Longer
X-ray exposure endangers the patient and decreases the likelihood
of obtaining satisfactory angiogram results. Moreover, side-holes
can cause pressure jets leading to PVCs and other arrhythmias, as
outlined above.
[0007] Although adding additional side-holes may increase the
volume of material allowed into the vessel while dissipating
pressure jets, such an increase may result in a distal region of
less strength than the main body of the catheter tube. As a result
of this reduced strength, complaints have arisen as to some
currently-available angiographic catheters from physicians, who
have reported that in clinical use, as they have attempted to put
the pigtail tip through the aortic valve, the distal tip area in
which the side-holes reside sometimes buckles.
[0008] It is therefore desirable to increase the volume of the
bolus of contrast material allowed to flow out of an angiographic
catheter in a short time span without decreasing the catheter's
rigidity near the distal end, and without inducing PVCs,
ventricular tachycardias or other arrhythmias. It is also desirable
to decrease the amount of material needed to create the bolus of
material within the opacified vessel.
SUMMARY OF THE INVENTION
[0009] This invention is directed to an endocardial catheter. The
catheter preferably incorporates an end-hole valve means and
deformable wings near the distal end. The end-hole valve means
functions to curtail undesirable jet effects and to decrease the
amount of contrast material and radiation required for optimal
angiographic results. The deformable wings adjacent the distal end
function to facilitate low-pressure entry of contrast material at a
high rate of flow to optimize chamber opacification and increase
the patient's safety and comfort.
[0010] Thus, one object of the present invention is to provide a
catheter in the form of a hollow, thin-walled tube having a
plurality of circumferentially-spaced longitudinally extending
slits through the thin wall adjacent the distal end. These slits
form a plurality of circumferentially-spaced longitudinally
extending flexible intermediate portions of the thin wall adjacent
the slits. The flexible intermediate portions are capable of
forming a plurality of wings extending from the tube to provide for
the discharge of fluid from the passageway out through the open
slits of the tube near the distal end.
[0011] A further object of the present invention is to provide a
flexible intermediate portion, shaped during fabrication to retain
a winged shape at the distal end. An external, removable cannula
dimensioned to sealingly fit over and collapse the tube to its
maximum length and minimum width and to compress the wings until
they return to a position flush with the wall of the tube can be
incorporated.
[0012] Still another object of the present invention is to provide
a catheter including and insertable over a guidewire or other
device to facilitate entry of the catheter's distal end into a
blood vessel. The catheter may also include a valve sealingly fit
into the distal end of the main passageway, wherein the valve opens
during the passage of the guidewire through the tube and valve. The
catheter may otherwise include a valve for at least partially
closing the main passageway at the distal end of the tube, wherein
the valve comprises a plurality of resilient flaps which flex when
exposed to the force of fluid pressure originating within the
passageway.
[0013] The apparatus of the present invention, including an
end-hole valve means as well as a plurality of
circumferentially-spaced intermediate portions capable of forming
wings, increases the likelihood of satisfactory vessel or chamber
opacification, decreases the number of cardiac arrhythmias and
endocardial damage resulting from pressure jet effects, and
decreases the amount of contrast material and radiation required
for optimal chamber or vessel opacification when used in cardiac
angiography, without significantly reducing the catheter's
resistance to buckling when used in highly tortuous endocardial
procedures.
[0014] Still other objects and advantages of the present invention
will become apparent to those skilled in the art as the disclosure
is made in the following description of the best mode contemplated
by me of carrying out my invention. As will be realized, the
invention is capable of other embodiments, and its several details
are capable of modifications in various obvious respects, all
without departing from the invention. Accordingly, the drawings and
description are to be regarded as illustrative in nature, and not
as restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The above and other features and aspects of the present
invention will become more apparent upon reading the following
detailed description in conjunction with the accompanying drawings,
in which:
[0016] FIG. 1 is a front elevational view of a human heart in
partial cross-section illustrating the distal end of the inventive
catheter within an endocardial vessel, namely, the left
ventricle;
[0017] FIG. 2 is a front elevational view of the preferred
catheter;
[0018] FIG. 3 is a fragmentary perspective view of the preferred
catheter according to the present invention with the intermediate
portions in the initial, non-extended position;
[0019] FIG. 4 is a view similar to FIG. 3, but with the
intermediate portions in the outwardly extended position forming
wings;
[0020] FIG. 5 is a longitudinal cross-sectional view of the
preferred catheter with the intermediate portions in the initial,
non-extended position;
[0021] FIG. 5-A is a longitudinal cross-sectional view of an
alternate embodiment of the preferred catheter with the
intermediate portions in the initial, non-extended position.
[0022] FIG. 6 is a right end elevational view of the preferred
catheter with the intermediate portions in the non-extended
position;
[0023] FIG. 7 is a longitudinal cross-sectional view of the
preferred catheter with the intermediate portions in the outwardly
extended position forming wings;
[0024] FIG. 8 is a right end elevational view of the same;
[0025] FIG. 9 is a fragmentary perspective view of the preferred
catheter with valve at the distal end;
[0026] FIGS. 10-A through 10-D provide a sequence of photographs of
a preferred embodiment of the catheter during an angiogram
procedure;
[0027] FIG. 11 is a graph of data related to contrast material
volume placed within a blood vessel during an angiogram procedure
using a preferred embodiment of the catheter;
[0028] FIG. 12 is a graph of data related to contrast material
volume placed within a blood vessel during an angiogram procedure
using a prior art catheter;
[0029] FIG. 13-A is a photo of a left ventricular angiogram with
the new catheter;
[0030] FIG. 13-B is a photo of a left ventricular angiogram with a
pigtail catheter;
[0031] FIG. 14-A is a photo showing a densely opacified aortic root
and right and left coronary arteries with its branches;
[0032] FIG. 14-B is a bargraph showing a comparison between the new
and pigtail catheters illustrating differences in dye density;
[0033] FIG. 14-C is a bargraph showing a comparison between the new
and pigtail catheters further illustrating differences in dye
density;
[0034] FIGS. 15-A through 15-D provide a prior art sequence of
photographs of a pigtail catheter during an angiogram
procedure;
[0035] FIG. 16-A is a graph of various dye density versus time
curves for a pigtail catheter;
[0036] FIG. 16-B is a photo of dye being injected into the left
ventricle through a pigtail catheter;
[0037] FIG. 17-A is a graph similar to FIG. 16-A above graphing
various density and time curves for a new catheter; and,
[0038] FIG. 17-B is a photo similar to FIG. 16-B above showing dye
being injected into the left ventricle through a new catheter.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0039] The catheter 10 of the instant invention, shown in FIG. 1,
is placed within a heart ventricle 12. As shown, the catheter is
placed within the left ventricle, although it could as easily be
placed within the right ventricle 14 or any other endocardial
chamber or site.
[0040] Turning to FIG. 2, there is shown the inventive catheter 10
having a distal end 16 and a proximal end 18 at the opposite end
thereof. A standard fitting 19 enables connecting the catheter to a
source of fluid under pressure, such as a power injector (not
shown).
[0041] As shown in FIGS. 3 and 4, the distal end 16 of the catheter
is comprised of a generally hollow flexible tube portion 20 of an
outer diameter 24 small enough to be passed through the blood
vessels and into the heart. Tube 20 may be made of flexible
material such as plastic or Dacron brand material, but is
preferably made of material with a "set" or "memory" for reasons
noted below. As shown in these figures and in FIGS. 5 and 6, tube
20 has an inner bore 22, of a lesser diameter than the outer
diameter 24, forming a passageway 50 through which a guidewire 26
or radiopaque contrast material (not shown) may pass. The distal
end 16 may be either normally straight as shown in the drawings, or
may be shaped into a circular pigtail configuration similar to that
of presently used angiographic catheters. The principles of the
invention therefore can be applied to pigtail catheters which are
used extensively in ventriculography.
[0042] Referring again to FIG. 3, the area adjacent distal end 16
is in its fully retracted position. Circumferentially-spaced slits
30 partially extend along the length of tube 20 near the distal end
and sealingly close when tube 20 is at its maximum length and
minimum diameter. Defined between slits 30 are intermediate
portions 32. To ensure tube 20 remains in its fully extended
position shown in FIG. 3 during placement of catheter 10, removable
sheath 28, shown in FIG. 5, may be sealingly fit around tube 20,
forcing the tube to its maximum length and minimum diameter
shown.
[0043] In FIGS. 4, 7 and 8, the area adjacent distal end 16 is in
its fully expanded position, which is caused by the "memory" of the
plastic from which it is made. Intermediate portions 32 have
deformed into wings 34, revealing cavity 36 in tube 20.
[0044] In an alternate embodiment, sheath 28 may be eliminated. In
this case, a short sheath (not shown) that is normally placed in
the artery or the vein is sufficient to collapse the wings until
the catheter is introduced into the artery or the vein. After the
catheter enters the artery or vein it will expand to the extent
required.
[0045] In a further embodiment shown in FIG. 5-A, a plurality of
internal annular ribs 21' are formed within the inner bore 22'
adjacent to the distal end. Parenthetically, structure having a
counterpart in the preferred embodiment of FIG. 5 is indicated by a
prime ('). The internal ribs 21' may be conveniently evenly spaced
along the inner bore 22' and of an internal diameter 23' which is
slightly less than the external diameter of guidewire 26'. The ribs
21' function as flow restrictors to resist axial flow of contrast
media. At the same time they facilitate radial flow of the media
trough the open slits (not shown).
[0046] In an example of operation, catheter 10, including tube 20
surrounded by sheath 28, is percutaneously introduced into a
patient and directed through a blood vessel (not shown) and into
the aorta 98, as best seen in FIG. 1. The distal end 16 is then
positioned within, for example, the left ventricle 12. Upon sliding
sheath 28 toward the proximal end 18 and away from the distal end,
tube 20 will assume the extended position shown in FIGS. 4, 7 and
8. Contrast material forced into catheter 10 through proximal end
18 is thereby allowed to pass through cavity 36 without
obstruction, forming a bolus of material within the desired
endocardial chamber. FIG. 7 clearly illustrates the flow of
contrast material out of cavity 36.
[0047] Also available for incorporation into catheter 10 is valve
40, shown in FIGS. 9 and 9-A. Valve 40 is preferably comprised of
material similar to that used for tube 20, but may be made of any
material having sufficient elasticity to perform the valve function
in the manner described herein. When the catheter 10 is inserted
into a blood vessel using a guidewire 26, as soon as the end of the
guidewire engages the flaps 42 of valve 40, the flaps 42 are
resilient will flex when acted on by the force of fluid pressure
within passageway 22 to permit passage of the guidewire 26 until
such time as it is withdrawn. When the guidewire 26 is withdrawn,
valve 40 will close and remain closed, as seen in FIGS. 9 and 9-A,
thus allowing for all of the fluid flowing through tube 20 to be
discharged through cavity 36. While three equal flaps are shown in
FIG. 9, it is to be understood that greater or lesser numbers of
flaps could be utilized. For example, a single slit at the distal
end 16 producing two flaps would also suffice. Inclusion of valve
40 will reduce the quantity of contrast material required for
effective angiography and will eliminate end-hole jets and their
concomitant effects.
[0048] A number of examples follow in order to illustrate the
comparative advantages of the inventive "new" or Desai catheter
described above.
Example 1
Left Ventricular Angiogram with a New Catheter
[0049] FIGS. 10-A, 10-B, 10-C, 10-D, 11 and 12 provide a
sequential, pictorial illustration of the operation of the current
invention and a quantitative comparison to a prior art catheter. No
end-hole valve is included in the embodiment shown in FIGS. 10-A
through 10-D or in any of the following examples, for that matter.
This accounts for the contrast material that is shown, which has
been expelled from the distal end of the catheter in these
figures.
[0050] FIG. 10-A shows a fluoroscope of one embodiment of the
present invention, an angiographic catheter, passed through the
aorta and positioned within the left ventricle of a canine heart.
The catheter comprises flexible intermediate portions which have
extended to become wings upon release of the surrounding sheath.
The contrast material has begun to flow from cavity and the
end-hole, forming a radiopaque bolus around distal end. FIGS. 10-B
and 10-C show the bolus progressively increasing with the continued
flow of the contrast material. FIG. 10-D shows the contrast
material dispersed throughout the volume of the left ventricle,
providing a complete outline of the ventricle's interior. Note the
even distribution of material throughout the ventricle and the
clarity of the outline provided by the preferred catheter
embodiment.
[0051] FIGS. 11 and 12 provide an effective performance comparison
of one embodiment of the inventive catheter to a prior art pigtail
catheter. The catheters used for the angiograms from which the
graphed data was taken have the same diameter, specifically No. 8
French. Fifteen cc of contrast material was injected using a power
injector at eight cc per second. Both catheters were placed at the
apex of a canine left ventricle, the preferred placement for
optimal contrast material dispersion. FIG. 11 is a graph
representing the effective coverage of the ventricle over time by
the subject embodiment of the present invention. FIG. 12
illustrates the same information as created by the prior art
pigtail catheter. The total areas covered below the graphed lines
provide a value for meaningful comparison of the two devices under
nearly identical conditions. The superior ventricular coverage by
the present invention when compared to the prior art catheter is
clearly apparent.
Example 2
Left Ventricular Angiogram with a Pigtail Catheter
[0052] The four serial pictures of left ventricular angiogram,
FIGS. 15-A through 15-D, shows 15 ml of Renograffin contrast dye
injected with a pigtail catheter at 8 ml per sec.
[0053] FIG. 15-A shows dye being injected in the left ventricle
through a pigtail catheter. A powerful jet of dye from the end hole
is seen striking the inferior (diaphragmatic) segment of left
ventricular wall. This jet effect can cause premature ventricular
contractions (PVC) or ventricular tachycardia (VT) rendering the
angiogram unusable for calculating left ventricular volume and
ejection fraction. The major bulk of dye is not injected into the
left ventricular apex but superior (anterolateral) and inferior
(diaphragmatic) to pigtail catheter. The dye does not opacify the
left ventricular chamber from apex to aortic root in an inferior to
superior direction. In this first picture, the dye is already seen
to be moving towards the aortic root.
[0054] The FIG. 15-B picture shows that the end hole jet continues
to strike the diaphragmatic wall. The dye has now opacified the
apex. The dye is moving superior to the pigtail towards the
anterobasal area and aortic root. The incoming blood from the left
atrium through the mitral valve (posterobasal segment) has caused
some mixing of the dye thus showing the faint outline of the
posterobasal and anterolateral segments of the heart.
[0055] The FIG. 15-C picture shows a very small amount of dye being
injected into the left ventricular wall from end hole and side hole
jets on the pigtail. These are the triangular shaped darker shadows
seen all around the pigtail loop. The dye is mostly concentrated in
the apex, inferior cavity and area superior to the pigtail. The
posterobasal segment near the mitral valve and left ventricular
outflow area has a very small amount of dye, barely opacifing the
outline of that area. Also aortic root is faintly visualized as
some dye has been ejected out of the left ventricle without fully
opacifing the left ventricle.
[0056] This FIG. 15-D picture shows almost all the dye is injected
into the left ventricle. The entire left ventricle is still not
well opacified. The dye in the posterobasal segment near the mitral
valve and left ventricular outflow tract does not well opacify
these areas. A significant amount of dye is ejected out into the
aortic root which is more densely outlined compared to the previous
picture. As the entire left ventricular chamber is not well
opacified, this is not an ideal angiogram to determine left
ventricular volume and ejection fraction. It took 660 msec (20
frames) to opacify the left ventricle.
Example 3
Left Ventricular Angiogram with Time Density Curves Showing
Comparison of New Catheter Versus Pigtail Catheter Near the
Apex
[0057] FIG. 13-A shows left ventricular angiogram (15 ml injection
at 8 ml per second) with new catheter. Renograffin Contrast Dye
(dye) almost opacities the left ventricle with very small amount
ejected from left ventricle to aortic root, which is barely
opacified. The bulk of dye from this catheter is injected into the
Apex.
[0058] The graph of FIG. 11 shows time density curves generated
from the area marked by a window at the Apex in FIG. 13-A. This
window is compared with a window outside the left ventricle. The X
axis shows elapsed time and Y axis shows density of dye. The
fluctuation in the curve is due to mixing and dilution of dye from
incoming blood, dye being injected from the catheter tip,
contraction of the Apex and ejection of dye from the ventricle. The
curve is smooth with rapid and persistent opacification of the area
of interest (Apex). The curve starts to plateau at 1.34 sees.
[0059] The picture of FIG. 13-B shows left ventricular angiogram
(15 ml injected at 8 ml per see) with pigtail catheter. Renograffin
Contrast Dye (dye) is injected away from the Apex. Large area of
Apex and cavity superior to Apex is unopacificed. Also a
significant amount of the dye is ejected from left ventricle to
aortic root opacificing the aortic root with almost the same
density.
[0060] The graph of FIG. 12 shows time density curves generated
from the area marked by a window at the apex in FIG. 13-B. This
window is compared with a window outside the left ventricle. The X
axis shows elapsed time and Y axis shows density of dye. The
fluctuation in the curve is due to mixing and dilution of dye from
incoming blood, dye being injected from the catheter tip,
contraction of the Apex and ejection of dye from the ventricle. The
fluctuations in this curve are more pronounced compared to the
curve in FIG. 11 (new catheter) because of the increased amount of
dye being ejected out from left ventricle to aortic root and
turbulence caused by mitral valve motion with each beat. The area
under the curve is 31% less compared to the new catheter. The curve
starts to plateau at 1.51 sec.
Example 4
Aortic Root Angiogram and Nonselective Coronary Angiography
[0061] The picture of FIG. 14-A shows an aortic root angiogram with
pigtail or new catheter showing densely opacified aortic root,
right and left coronary arteries with its branches. For both
catheters two injections are performed in the aortic root at 9 ml
and 18 ml (8 ml per see). A window is placed on the left aortic
cusp to compare the maximum density with the smaller background
window which is just above the cusp. The second window is placed on
the left coronary artery to compute the maximum density with
reference to the same background window.
[0062] The graph of FIG. 14-B picture shows comparison of maximum
density of dye in the cusp at 9 ml and 18 ml. At 9 ml there is no
significant difference between the new catheter ("D") and pigtail
catheter ("P"). At 18 ml the new catheter shows about 15% more
density of dye.
[0063] The FIG. 14-C picture shows maximum opacification of
coronary arteries. The picture shows nonselective coronary
angiogram of left anterior descending and left circumflex coronary
arteries. The injection was in the aortic root with Renograffin 15
ml at 8 ml per sec. The bargraph shows the maximum density of dye
in the coronary artery with pigtail or new catheter. In both,
anterior descending and left circumflex arteries the new catheter
opacification is 100% more dense than the pigtail catheter.
Example 5
Patterns of Renograffin Contrast Dye Distribution in the Left
Ventricle During Left Ventricular Angiogram with Pigtail
Catheter
[0064] FIGS. 16-A and 16-B show patterns of distribution of
contrast material in the left ventricle. To uniformly opacify left
ventricle, ideal site of contrast injection is in the apex. When
dye is injected in the apex, opacification of left ventricle occurs
in inferior to superior direction (from apex to aortic root). The
injection of dye in the apex minimizes the ejection of dye from
aortic root and achieves opacification of the chamber with minimal
loss.
[0065] In the FIG. 16-B picture, dye is injected into the left
ventricle through a pigtail catheter (15 ml at 8 ml per sec). The
small squares show areas of interest to compute the density time
curve of dye in that region. The areas are as follows: [0066] APEX
(apical) [0067] SUPERIOR (anterolateral) [0068] INFERIOR
(diaphragmatic) [0069] MITRAL VALVE (posterobasal) [0070] AORTIC
ROOT
[0071] Referring to FIG. 16-A, the various curves are density of
dye versus time curves. The lowest curve is the R wave curve
showing 3 heart beats including a PVC and a post PVC beat. All
curves are together for a very short time. The apex curve lags
behind suggesting that dye is not continuously injected in the
apex. The inferior and superior curves show identical density time
relationship with wild fluctuations suggesting ejection of dye and
dilution of dye from incoming blood. The apex density increases at
2.4 sec suggesting that the dye is concentrating in the apex late.
At 1.05 sec there is a major ejection of dye from the left
ventricle into the aorta. This forceful prolonged ventricular
contraction is produced by a post premature ventricular beat.
[0072] This pigtail catheter does not uniformly inject the dye in
the apex and thus does not uniformly opacify the ventricle from
apex to aortic root in the inferior to superior direction. This
results in nonuniform opacification of the left ventricle with loss
of dye by ejection into the aortic root. Also because of jet
effects, premature ventricular contractions and ventricular
tachycardia can make left ventricular angiogram nonusable for
calculation of left ventricular volume and ejection fraction.
Example 6
Patterns of Renograffin Contrast Dye Distribution in the Left
Ventricle During Left Ventricular Angiogram with New Catheter
[0073] These two figures, FIGS. 17-A and 17-B, show patterns of
distribution of contrast material in the left ventricle. to
uniformly opacify left ventricle, ideal site of contrast injection
is the apex. When the dye is injected in the apex, opacification of
left ventricle occurs in inferior to superior direction (from apex
to aortic root). The injection of dye in the apex minimizes the
ejection of dye from aortic root and achieves opacification of the
chamber with minimal loss.
[0074] In the picture of FIG. 17-B dye is injected into the left
ventricle through a pigtail catheter (15 ml at 8 ml per sec). The
small squares show areas of interest to compute the density time
curve of dye in that region. The areas are as follows: [0075] APEX
(apical) [0076] SUPERIOR (anterolateral) [0077] INFERIOR
(diaphragmatic) [0078] MITRAL VALVE (posterobasal) [0079] AORTIC
ROOT Most of the dye is injected into the apex, inferior and
superior aspect of the left ventricle. All three curves remain
together without wild fluctuation suggesting the majority of dye
being injected in these areas. The ejection from ventricle into
aortic root is also more uniform and occurs after 1.125 sec. This
angiogram suggests opacification of the left ventricle occurs from
inferior to superior direction (from apex to aortic root).
[0080] The mitral valve curve fluctuations are due to incoming
blood from the left atrium diluting and mixing the dye.
[0081] The new catheter uniformly opacifies the left ventricle from
apex to aortic root without significantly losing the dye before
opacification is completed.
[0082] Various details of the implementation and method are merely
illustrative of the invention. It will be understood that various
changes of details may be within the scope of the invention, which
is to be limited only by the appended claims.
* * * * *