Note: Descriptions are shown in the official language in which they were submitted.
Background of the Invention
Field of Inven-tion -
The present invention relates to an intravascular
method and apparatus for closure of septal defects or shun~s
in the intravascular system or the great vessels by means
of a positive mechanical structure applied by means of
an outer catheter and other associated operative elements
wor]~ing within said outer catheter.
- General Background - -
In order to gain a better understanding of the
present invention and its particular application, it is
noted that the heart is divided into four compartments
or chambers, the two upper being the left and right atria
and the two lower being the left and right ventricles.
The atria are separated from each other by a muscular wall,
the interatrial septum, and the ventricles by the interventri-
cular septum. ~
Either congenitally or by acquisition, abnormal ~ -
openings, holes or shunts can occur between the chambers
of the heart or the great vessels (interatrial and lnterven-
tricular septal defects or patent ductus arteriosus and aortico-
pulmonary window respectively), causing shunting of blood
through the opening. The deformity is usually congenital,
resulting from a failure of completion of the formation
of the septum, or wall, between the two sides during fetal
life when the heart forms from a folded tube into a four~
chambered, two unit system.
These deformities can carry significant sequelae.
For example, with an atrial septal defect, blood is shunted
from the left atrium of the heart to the right, producing an
over-load of the right heart. In addition to left-to-right
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shunts such as occur in patent cluctus arteriosus from the
aorta to the pulmonary artery, the left side of the heart
has to work harder because some of the blood which it pumps
will recirculate through the lungs instead of going out to
the rest of the body. The ill effec-ts of these lesions
usually cause added strain on the heart with ultimate heart
failure if not corrected.
- General Discussion of Prior Art and Present Invention -
Heretofore these intracardiac or extracardiac
septal defects have required relatively extensive surgical
techniques for correction. In 1938 surgeons first seriously
entered the field of attacking congenital heart disease when
Gross reported the first ligation of a patent ductus arterio-
sus. Since that time rapid advances have allowed thoracic
surgeons to close not only extracardiac congenital shunts
but also shunts between the chambers of the heart. The
modern era of extracorporeal circulation began in 1953 when
Gibbon first closed an atrial-septal defect, using the heart-
lung machine. To date the present method of closing intra-
cardiac shunts, such as atrial-septal defects and ventricular-
septal defects, entails the relatively drastic technique of
open~heart surgery, requiring opening the chest or sternum
and diverting the blood from the heart with the use of a
cardiopulmonary bypass. The heart is then opened, the defect
is sewn shut by direct suturing with or without a patch of
synthetic material (usually of Dacron*, Teflon*, silk, nylon or
pericardium), and the heart closed. l'he patient is then taken
off the cardiopulmonary bypass machine, and the chest closed.
In place of direct suturing, it has been suggested
that closures of interauricular septal defects could be made by
means of a double "button" prosthesis, but open heart surgery ;
* Trade marks
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was~still required. See for e~ample "Closure of Interauricular
Septal Defects" by Charles A. Hufnagel et al, The Bulletin
Georgetown University Medical Center, Vol. IV, No. 5, Pp. 137-
139, Feb.-Mar., 1951; which also cited Swan H.: "Experimental
Closure of Interauricular Septal Defects" - Symposium of
Cardiovascular Research, National Institute of Health, Jan. 21,
1950, Washington, D. C. Additional work with such a button-
type prothesis in open heart surgery was also apparently done
by C. P. Bailey, M.D. (see Bailey et al: "Correction of Inter-
1~ ventricular Septal Defects," Am Surgery, 136, 919, 1952; and
Bailey: "Surgery of the Heart," Lea and Febiger, Philadelphia,
Pp. 366, 1955) and by Yousif D. Al-Naaman, M.D., Department of
Thoracic and Cardiovascular Surgery, University of Baghdad,
Iraq.
Thus, prior to the present invention, it was onl~
possible to repair septal defects or shunts through open-
heart surgery, involving shunting the blood through an arti-
ficial pump-oxygenator (heart-lung machine) or at least
supplanting the action-~of the heart itself (mechanical heart)
while the heart is being repaired. Moreover, although ex-
cellent results have been obtained on simple septal defects
by open-heart surgery, there is great risk in open-heart
surgery in patients whose heart muscles have been under
great strain for long periods of time.
In contrast to the relatively drastic technique
of open-heart surgery, the system of the present invention
closes off septal defects or shunts without the need of
general anesthesia or opening of the chest. Instead the
operative techniques employed in the present invention re-
quire only a small incision over a vein in the groin orneck under only local anesthesia, such as is carried out for
many routine cardiac catheterizations.
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Moreover, the catheter/closure system oE the present inven-
tion allows a cardiologist to close a septal defect at the time of
diagnostic cardiac catheterization, if desired. Because of the
proposed size of the outer catheter used in the present invention,
this would be most reasonably carried out after the age of 4 to 5
years.
In addition to a far superior, less drastic surgical proce-
dure, the present invention achieves this by means of a unique,
permanent catheter/closure system utilizing an expandible catheter/
closure structure formed by relatively inexpensive, positive
mechanical elements which are relatively simple and reliable in
structure and made of readily available and proven materials. In
the preferred embodiment of the present invention the catheter/
closure structure includes either a single expandible umbrella-
like element or an opposed pair of expandible umbrella-like ele-
ments, depending on the location of the septal defect.
It is noted that the term "catheter" as used herein refers
to an instrument, generally tubular in shape, which is inserted in-
to the body cavity, naturally or surgically opened. Several dif-
ferent catheters have been developed in the past, either for ex-
perimental research purposes or clinical application. The Mobin-
Uddi~ catheter is one that is used for partial occlusion of the
inferior vena cava to prevent pulmonary embolization. This cathe-
ter has been described in a publication by Drs. Kazi Mobin-Uddin
and ~ames ~. Jude in an article entitled 11~ New Catheter Technique
of Interruption of the Inferior Vena Cava for Prevention of
Pulmonary Embolism", The American Surgeon, Volume 35, page 889,
December 1969. See also U. S. Patent No. 3,540,431 to
Dr. Kazi Mobin-Uddin issued November 17, 1970. A similar ` -
catheter technique, but using a balloon obstruction instead
of an umbrella type obstruction, is disclosed in the article
"Experimental Balloon Obstruction of the Inferior Vena Cava"
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.,. ;~::
by ~lunter ~t al, A nnals of Sur~ery, Vol. 171, No. 3, Pp. 315-
320, February 1970.
Additionally, in experimental work performed by
one of the co-inventors himsel~,a cardiac catheter with
an inflatable disc balloon for interim closure of left-to-
right shunts through the ventricular septum was used. This
catheter has been described in a publication by Dr. Noel
L. Mills et al in an article entitled "Balloon Closure of
of Ventricular Septal Defect," Supplement I to Circulation,
Vols. XLIV, page I-lll, May 1971. See also the article
by Dr. Harold King et al entitled "Experimental Surgical
Repair of Ventricular Septal Defects", SURGERY, Vol. 34,
pp. 1100 - 1116, December, 1953.
Diverse examples of other expandible and/or
umbrella-like elements generally used in other types of
surgical applications are found in the following U.S. patents:
P ent No. Inventor(s) Title Issue Date
2,493,326 J. H. Trinder "Tampon For Control 1/30/50
of Intractable Nasal
Hemorrhages"
2,7Y9,273 V. J. Oddo "Haemostatic Catheter" 7/16/57
3,334,629 B. D. Cohn "Occulsive Device 8/8/67
For Inferior Vena
Cava"
3,397,699 G. C. Kohl "Retaining Catheter 8/20/68
Having Resiliently
Biased Wing Flanges"
3,592,184 David H. Watkins "Heart Assist Method 7/13/71
Erwin J. Klink And Catheter"
3,671,979 Spyridon "Catheter Mounted 6/27/72
Artificial Heart
Valve For Implant-
ing In Close Prox-
imity To A Defec-
tive Natural Heart
Valve"
5;3(:~
, .. . . . .. . . ... . .. . . .. .. . . . ... . .. . . .
~53~9~
However, as should be fully appreciated and under-
stood from the detailed description of the preferred embodi-
ments below, all of these diverse prior art catheters and
umbrella-like elements, neither collectively nor individually,
anticipate or make obvious the present, ploneering and far-
reaching invention.
~ he present invention in its earlier embodiments
has been experimentally tested with dogs with success, as
described in the article "Nonoperative Closure of Atrial
Septal Defects" by the inventors hereof which appeared in
the March, 1974 issue of Sur~ery (Vol. 75, No. 3, pp. 383-
388). With the further development work and later embodiments
as described herein, the shunt defect closure system of the
present invention is expected to be applied to human patients
in the very near future.
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M~re particularly in accordance with the invention there
is provided, a shunt de~ect closure apparatus for closing off
a shunt defect in the septum of the intravascular system
comprising:
mecharlical expansion means having an initial size sub-
tantially smaller than the diameter of the shunt defect to be
closed during its preliminary handling and a final size sub-
stantially larger than the diame~er of the shunt defect when it
is positioned over and across the shunt defect to permanently
close it off after being expanded to its larger size, said
expansion means comprising at least one umbrella-like structure ;
for placement on one side of the shunt, said umbrella-like
structure having central hub means of at least a generally
cylindrical shape for having pressure applied to it along its
longitudinal axis for ~rcing the distal, end portions of the
underside of said umbrella-like structure against the septum to
at least partially close the shunt, the main surface of the
umbrella-like structure in its expanded size being at least
substantially perpendicular and radial to said central hub
means and hence to the central axis of the shunt; and operative
means removably connected with said expansion means for at least
temporarily holding said expansion means on to the shunt defect.
The expansion means may comprise a dual set of umbrella-like
structures for placement on opposite sides of the shunt defect,
each umbrella-like structure having a central hub for connecting
the dual set together through the shunt. The umbrella~like
structure may comprise a series of supporting struts with flexible
material between the struts, the struts being moveably attached
to a centrally located support element. The distal tips of these
struts may include barb-like structures which bear against the
septum. The umbrella like structure may be of a material which
will be endotheliali~ed into the septum.
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Brief Description of the Drawings
For a further understanding of the nature and ob-
jects of the present invention, reference should be had to the
following detailed description, taken in conjunction with the
accompanying drawings, in which like parts are given like
reference numerals and wherein:
Figure lA is a schematic illustration of the heart,
partially cut away, showing the applied closure structure of
the prèsent invention closing off an atrial septal defect with
two of the catheter operative elements of the catheter/closure
system of the present invention being withdrawni while
Figure ls is similar in perspective to Figure
lA showing a typical atrial septal defect (ASD) prior to the
application of the present invention.
Figure lC is a perspective view of the left and right
umbrella-like closure elements used for an ASD in their open
or erected positions. '~
Figure 2~ is a side view of the left umbrella-like
closure element of the present invention in its collapsed position
with the inner, central sliding sleeve shown partially in
phantom lines; while
Figures 2B and 2C are side, cross-sectional and end
views, respectively, of the inner, central hub of the left
~ umbrella-like closure element of Figure 2A.
Figure 3A is a side view of the right umbrella-like
"'
closure element of the present invention in its collapsed
position with the inner, central sliding sleeve shown par-
tially in phantom lines; while
Figures 3B and 3C are side, cross-sectional and
end views, respectively, of the inner, central.sliding sleeve
of the right umbrella-like closure element of Figure 3A.
.
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Figure 4 is a side view of a typical strut element used
in the left and right umbrella-like closure elements of the pre-
sent invention
Figure 5 is a perspective view of three of the cathe~er
operative elements, concentrically assembled together, which are
used in the method of the present invention.
Figure 6 is a side, perspective view, partially cut away,
of the catheter operative elements with the left umbrella-like
closure element attached to the central one with the struts there-
of partially opened, portions of the umbrella-like element, parti-
cularly the covering ma~erial, not being illustrated for simpli-
city purposes; while
Figure 7 is similar to Figure 6 with the exception of
showing the right umbrella-like closure element being affi~ed to
the central one of the catheter operative elements and showlng an
additional operative element, a control disc, positioned of the
proximal end of the central catheter operative element~
Figure 8 is a side view of the cone operative element
used in the method of the present invention to initially close
the umbrella-like elements prior to their insertion into the outer
catheter operative element.
Figures 9A through 9K are side, schematic views of the
inner heart structure illustrating the sequential ste~s of the
method of the present invention as being applied to the closing
of an atrial septal defect (ASD); while
Figures lOA and lOB are right and left end views,
respectively, of the umbrella-like closure elements of the pre-
sent invention after being applied and locked together to cl~se
off the atrial septal defect.
_ 9 _ . ~
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Figure 11 is a side, cross-sectic,nal view of the central
hub and sleeve structures of the leEt and right umbrella-like
closure elements locked together in a male-female relationship.
Figures ]2A and 12B are side, cross-sectional and side,
perspective views, respectively, of two other structures allowing
two other alternative methods of opPning or erecting the umbrella~
like structure of the right umbrella-like closure element.
Figure 13A is a schematic illustration of the heart,
partially cut away, showing the applied closure structure of the
present inven~ion closing off a ventricular septal defect with an
alternate method utilizing a single umbrella-like element being
used; while
Figure 13B is similar in perspective to Figure 13A
showing a typical ventricular sep~al defect (VSD) prior to the
application of the present invention.
Figure 13C is a perspective view of the single umbrella-
like closure elemPnt used for a VSD in its open or erected
position; while
Figure 13D is a side view of the special obturator wire
used in the alternative single umbrella technique.
Figure 14A is a schematic illustration of the heart,
partially cut away, showing the applied closure structure of the
present invention closing off a patent ductus arteriosus (PDA)
using a modified right or second umbrella-like closure element
with the finaI catheter operative element of the catheter/closure
system of the present invention ready to be withdrawn; while
Figure 14B is similar in perspective to Figure 14A
showing a typical patent ductus arteriosus (PDA) prior to the
application of the present invention.
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Figure 14C is a perspective view of the modified
left and right or first and second umbrella-like closure
elements used for a PDA in their open or erected positions.
Figur~ 15A is a side view of a second basic
embodiment of the right umbrella-like element of the present
invention shown mounted on the obturator wire prior to its
being applied to the shunt; while
Figure 15B is a side view of the embodiment of
Figure 15A as it is being applied to the shunt and being
pushed to its locking position with the left umbrella-like
element; while
Figure 15C is a close-up, side view of the central
portions of the umbrella-like closure elements in their final,
locked position.
Figures 16A and 16B are frontal views of the under-
side and topside respectively, of the most recent embodiment
of the left umbrella-like closure element of the present
invention in its open position for closing an ASD; while
Figures 17A and 17B are frontal views of the
underside and topside, respectively, of the most recent
embodiment of the right umbrella-like closure element in its
open position used with the left unbrella-like closure element
of Figures 16A and 16B.
Figure 18 is a side view of the proximal ends of the
catheter operative elements used with the closure elements
of Figures 16 and 17; and
Figure 19 is a side view of the distal ends of the
catheter operative elements of Figure 18 without the umbrella-
like closure elements attached; while
~L09LX3~4
Figure 20 is a side view again of their distal ends
as in Figure 19 but with the left and right umbrella-like
closure elements attached and in their open positions located
as they would be on opposite sides of the septum (not illustrated)
and prior to being pushed and locked together.
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Detailed Description of the Preferred Embodiments
- Closure Structure And Operative Elements -
The closure structure of the present invention
must be expandible, fulfilling the special requirement of
being a structure which has a first, smaller physical form
while it is being inserted through a blood vessel and quite
a different, second, larger form when placed in its final
location closing and covering the septal defect or shunt.
Additionally i~ must meet the several stringent mechanical
requirements placed upon it, must reliably open at the desired
time and place, and must effect a suitable tight closure
of the defect or shunt in the heart system for a long period
of time without any deterioration and without producing
any u~wanted side-effects either on tissue or blood. Many
~4c c~n ~ co/
maahania~1 systems are conceivable to meet these requirements
and a most suitable one has been developed and tested and
comprises the preferred structural embodiment of the present
invention, which will now for purposes of illustration
and disclosure only be described in detail.
The disclosure structure of the preferred embodiment
of the present invention, as illustrated in Figures lC,
2 and 3 comprises a paix of opposed, umbrella-like elements
l~ 8, 9, a first element 8 having a central, tapered hub 84
and a second element 9 having a central, sliding sleeve 94.
The two umbrella-like closure elements 8, 9 of
the preferred embodiment of the present inventiOn have for
example six material supporting struts 81, 91, respectively,
each (note Figure 4). Each strut 81, 91 has for example a
length of 5.35mm., with a sixty degxee angle between the
struts 81, 91. The struts 81, 91 are made of a radiopaque
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material (not necessarily metallic), for example stainless
steel, which have at the distal ends thereo~ small projec-tions
or barbs 33, 93, respectively, of for example 0.2 mm. length,
which allow anchoring of the closure elements 8, 9 into
the septum. Three holes are provided along the length of
the struts 81, 91 - hinge holes 86l, 96'; tie eyes 87a,
97a for raising or lowering the struts 81, 91 by means of
ties or lines 7; and ~uture eyes 87b, 97b for attaching
the umbrella material 82, 92 to the struts 81, 91. The
tie holes 87a, 97a are of sufficient size to allow the ties
7 to slide easily ~hrough them.
The struts 81, 91 are attached to the umbrella-
like closure elements 8, 9 through a central hub 84 and a sliding
sleeve 94, respectively, made of for example stainless steel.
The surfaces of the hub 84 and the sleeve 94 are grooved
(note Figures 2C and 3C) in such a manner to allow the struts
81, 91, respectively, to lie superficially in their surfaces
without adding to the exterior bulk of the umbrella-like struc-
tures. The struts 81, 91 are movably attached to the hub 84
and sleeve 94 by hinge ring elements 86, 96, respectively, and
there are included ring-like strut keepers 87, 97, respectively,
to prevent the struts 81, 91 from opening respectively, beyond
ninety degrees. Each umbrella-like element 8, 9 is of small
enough size to allow it to be placed within the outer, thin
wall catheter 1 within which it is transported during applica-
tion, as described more fully below.
i Thin Dacron, Teflon, nylon, s~æ~r; pericardium
. ~,~
or silk, for example, routinely used to close intercardiac
defects in open-heart surgery, can be used for the umbrella
sheet material 82, 92, although Dacron and silk are considered
preferable. The material 82, 92 should be pliable and o-f
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sufficient strength and resiliency to open and close smoothly.
Although the umbrella material 82, 92 could be fanfolded be-
tween the struts 81, 91, respectively, it is preferred that
instead it be stretched or extended flat over the struts. It
thus retains a certain amount of resiliency which further aids in
opening the umbrellas 8, 3. The material 82, 92 is anchored
centrally on the hub 84 and the sliding sleeve 94, respectively
between the main body thereof and the strut keepers of 87,
97, respectively. Additionally small holes 87b, 97b are
made in the struts 81, 91 so that, for example, Tycron sutures -
87b', 97b' can be used to secure the umbrella material 82,
92, respectively, distally upon the struts 81, 91. Additionally,
supplemental sutures 87a' can be used if desired to further
secure the material 82, as the eyes 87a have not been found to
be otherwise necessary.
The sliding sleeve 94 and the distal hub 84 are
designed to lock securely together in opposed, facing relation-
ship by means of an internal, central, male-female mechanism
~note particularly Figure 11). A typical structure for
achieving this is illustrated particularly in Figure 11
with supplemantal reference to Figures 2B and 3B. r~he hub
84 includes a male member 84' projecting inwardly and having
a locking plateau 85 on its outer surface. This mates with
the female cavity formed within the inner portion 94' of
the sleeve 94. The female cavity also includes a locking
groove 95 for mating with the plateau 85.
The total external diameter of the hub 84 is for
ex~mple 3.3 mm., and it has been engineered with grooves
89 so that the struts 81 are recessed within the surface and
30 do not occupy any additional space within the outer catheter
1. The hub 84 is tapered slightly to a rounded, bullet-
shape configuration at the distal end to a diameter of ~or
example approximately 0.075 mm. The proximal end o the hub 84
is relatlvely blunt and has a central threaded oriflce 80
for mating with the threaded end 31 of the obturator wire 3,
described more fully below. The hub 84 can be for example
3 mm. in length.
Although it has not been found to be necessary, the
central sliding sleeve 94 of the right umbrella 9 could have a
flared or conical distal end in order to center it automatically
with respect to the hub projection 84' as a prelude to sliding
up over it and along it to the locked position. The bore 90 of
the right sleeve 94 is considerably larger than the diameter of
the obturator guide wire 3, described below, to allow for free
movement thereon.
The operative elements of the closure catheter
system of the preferred embodiment of the present invention
comprise several parts: an outer catheter l; an inner,
locking catheter 2; an obturator guide wire 3; a loading cone 4;
a manipulating "T"-piece 5; and a tie retracting and control
disc 6 with a series of manipulating ties 7. Note particularly
Figures 5, 7, 8 and 9J.
The outer, thin wall catheter 1, for example a
#24 French size, is of sufficient length (for example 80-105
cm.) to allow its manipulation into the heart area. The outer
catheter 1 can be ma~,e fr,om thin wall, woven Dacron or
a~/o~e
preferably polyvinyl~material and has a gentle curve at the cardiac
end to allow easy manipulation through a septal defect in the
cardiac area.
As shown in Figure 5, inside the outer, thin wall
catheter 1 is a second, radiopaque, inner catheter ~ whi,ch
o~ e ~6~ r ~6~ /
could be for example a #5 French size catheter of polyvinyl~
It should be of sufficient length (for example 90-110 cm.)
to protrude from the proximal end of the outer catheter 1 and
has a rounded, cone shape distal hub 21 (note Figure 9C). The
inner catheter 2 should be of a size to be quite mobile through
the outer catheter 1.
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Passing through the inner catheter 2 is an obturator
guide wire 3 which can be for example 1.1 mm. or less in diameter
and have a length of for example 200-350 cm. ~ removable, proxi-
mal "T"-piece 5 (note Figure 9J) is used for rota~ional manipula-
tion of the obturator wire 3. The "T"-piece is locked to the
obturator wire 3 and is easily removable therefrom by means of a
locking set screw 51 going through the central hub element 53.
For gripping purposes an extention arm 52 is provided~
The cardiac or distal end 31 of the obturator wire 3 is
threaded for approximately l mm. so that it ~ay be screwed and
unscrewed into the distal hub 84 of the left closing umbrella 8.
The obturator wire 3 should be of sufficient flexibility to allow
easy manipulation and can be for example made of a fixed core
stainless steel spring material.
As shown in Figure 7, a control disc 6 is provided for
ease in manipulating and controlling the ties or suture lines 7.
Thc disc can be made of stainless steel and is placed on the
exterior, proximal portion of the obturator wire when needed. A
series of hole pairs 61 are provided about the periphery of the
disc for holding the ties 7. Although not illustrated, the holes
61 could be numbered or coded to the particular struts involved
and an additional pair of holes can be provided for the retracting
ties 7'. The ties 7, 7' can be made of for example monofilament
nylon or 3-0 silk.
The final operative element is the loading cone -
4, illustrated in Figure 8. The loading cone 4 is provided
to assist in the eas~ loading or insertion of the umbrella-
like elements 8, 9 into the outer catheter l. For example,
as shown in Figure 8, the left umbrella 8, threaded onto
- 16 ~
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the distal end 31 of the obturator wire 3 and in its open
or partially opened position, is first inserted through the
loading cone 4 which leads into the outer cathe~er 1. The
cone 4 serves to close the umbrellas 8, 9 making them of
a small enough size for insertion into the outer catheter 1.
The distance across the total closure structure
from hub tip to sleeve tip (note Figure 9K) once locked
in place is only approximately 3.5 mm., elements can be
produced in diameter sizes of for e~ample 10 mm., 15 mm.,
20 mm~, 25 mm., 30 mm. and 35 mm. as desired or needed.
Thus, an effective and reliable embodiment is
provided for a typical closure structure and associated
operative elements. Of course many, other structures are
possible, the variations being practically limitless. For
example, rather than dual, opposed umbrellas, a single
umbrella could be used as described more fully below
with respect to the repair of a ventricular septal defect.
Additionally the means of expanding or opening
the umbrella can be easily varied. For example as generally
shown in Figure 12A the struts 91' of the right umbrella
can be machanically forced open by appropriate shoulder and
flange elements 97' as the sleeve 94a is pushed and locked
into the hub 84. Alternatively, as generally illustrated in
Figure 12B, the struts 91" could be made of resilient,
flexible material so that the umbrella will inherently or
automatically open once it emerges from the;outer catheter
~note the movement of the phantom lined strut).
An additional, very effective, exemplary embodi-
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ment of the right umbrella is shown in Figures 15A-C in
which the necessity of a tie wire system is eliminated.
The umbrella 209 is similar in general s-tructure to the
right umbrella 9 except that in place of the tie wire
system there is included a set of elevating struts 291'
hingedly attached between the regular umbrella struts 291
and the elevating sleeve 294'. As shown in Figure 15B, as
the elevating sleeve 294' comes into contact with the hub
84, the umbrella becomes erected under the continuing
pressure of the inner catheter 2 until it is locked into
place as shown in Figure 15C.
Finally, although an umbrella-type structure
is thought to be particularly effective, other expansion
systems, i.e.~ the elements which initially have a rela-
tively small size for insertion and positioning and which
then expand to a relatively large size when in place, are
possible and likewise nearly limitless. For example, in
place of the umbrella elements, a balloon(s) or other inflat-
ab1e structure(s) could be used.
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- Typical Method of Application -
For purposes of illustration and disclosure
purposes only, the method of application of the present
invention will now be described in;detail with respect to
the closing of an atrial septal defect (ASD) with particu~
lar reference to Figures lA-C and 9A-K.
In order to gain access to the heart, an incision
is made in either the right or left groin under local anesthesia,
and the femoral vein isolated~ Standard catherization techniques
are then utilized to confirm the presence of the ASD such
as the one shown in Figure lB. Once confirmed, sizing of
the AS3 is then achieved by means of special but standard
balloon catheters, and the appropriate size of umbrella-
like closure elements 8, 9 are selected.
The initial closing/catheter assembly (note Figure 5),
i.e. elements l, 2 and 3, the latter having the left umbrella
8 attached to its threaded end 31, is then insertéd via the femoral
7~/6~o~'~ s~O,~
vein into the heart under continuous ~4~æ~h4e~a control into
the right atrium. With further advancing of the catheter ass-
embly, it is placed in the left atrium (note Figure 9A).
By manipulating the obturator wire 3, the distalhub 84 carrying the collapsed left umbrella 8 is advanced
beyond the outer, thin wall catheter 1 into the left atrium
(Figure 9B). Once the left umbrella 8 is pushed beyond
the tip of the outer, thin wall catheter l, the umbrella
8 is initially unfolded by pushing the inner catheter 2
against the struts 81 and holding fast the obturator wire
3 (Figure 9C), expanding the umbrella out in excess of the
diameter of the outer catheter 1.
-19- :'
Then by pulling gently on the obturator wire 3,
the umbrella 8 is pulled against the distal end 11 of the
outer catheter 1, opening the umbrella 8 to its full ninety
degree position (Figure 9D). The outer catheter 1 is then
pulled back into the right atria and the umbrella 8 pulled
snugly against the left atrial septum, with the distal
barbs 83 being anchored against the septum (Figure 9E)o
Once the left umbrella 8 is firmly fixed, the
inner catheter 2 is withdrawn and removed and the right
umbrella 9 slid unto the obturator wire 3 and loaded inko
the outer catheter 1 with the retraction ties 7 and retracting
ties 7' in place on the struts 91 and sleeve 94, respectively,
and the disc 6 (note Figure 7). The collapsed right umbrella
9 is then pushed through and out the outer catheter 1 by
means of the inner catheter 2 into the right atrium and
positioned just superior to the inferior vena cava and right
atrial junction (Figure 9F). At this point the outer catheter
1 is withdrawn to allow the right umbre~la 9 to lie freely
upon the obturator guide wire 3 wi-thin the body of the right
atrium.
As the inner catheter 2 is advanced and traction
maintained on the elevating ties 7 and on the retracting
sutures or ties 7', the right umbrella 9 is opened (Figure
9G) and pushed snugly against the inter-atrial septum by
means of the inner catheter 2. By fluoroscopic monitoring,
it can be determined that all six struts 91 are at right
angles. The inner catheter 2 is pushed further forward,
forcing the sliding sleeve 94 of the right umbrella 9 to
slide onto the left umbrella hub 84, locking the two together
(Figure 9H). A clicking sensation is felt through the obturator
wire 3, and a click can be heard as the umbrellas 8, 9 are
-20-
53q~
locked into place. Once in place the umbrellas 8, 9 are tugged
gently with the ohturator guide wire 3 to assure stability.
Once the umbrellas 8, 9 are locked in place, the
obturator wire 3 can be unscrewed from the distal hub 84,
using the "T"-piece 5 on the proximal portion of the obturator
wire 3, thus leaving in place the distal hub 84 with the
right and left umbrellas 8, 9 locked in place (Figure 9J).
The obturator guide wire is thus unthreaded with the aid
of the "T"-piece 5 from the left umbrella hub 84 and removed
from the heart with the outer and inner catheters 1, 2 (Figure
9K). Following this, the outer, thin wall catheter 1,
the inner catheter 2 and the obturator wire 3 are completely
withdrawn from the body.
Following installation of the closure structure,
a diagnostic venous catheter can be introduced for the appro-
priate angiograms, dye CurvQs and hydrogen electrode studies
to confirm the effectiveness of the closure of the septal
defect. The closure structures 8, 9 should be covered by
endocardium within six to eight weeks, and be thereby inte-
grated into the heart's structure.
After completion of the operation, the vein andinguinal incision are closed.
~ :'
, .,
-21-
3~9L
- Additional Methods of Application -
For purposes of further illustration and disclosure, the
method of application of the present invention will now be de-
scribed in some detail with respect to the closing of a ventricu-
lar septal defect (VSD) with particular reference to Figures 13
A-C.
In order to gain access to the heart, an incision is
made in the right neck over the ex-ternal or internal jugular vein
under local anes~hesia. The jugular vein is isolated and veno-
tomy is made for insertion of the outer catheter 1. Standard
catherization techniques are then utilized to confirm the presence
of the VS~ such as the one shown in Figure 13 B. Once confirmed,
sizing of the VSD is then achieved by means of special but stan-
dard balloon catheters, and the appropriate size of the left
umbrella-like closure elemen~ 8' is selected.
The outer catheter is inserted into the vein and subse-
quently passed into the right heart and manipulated across the
ventricular septal defect into the left ventricle. Its position
can be documented by obtaining an oxygen sample or passing an MIH
catheter through the outer catheter into the left ventricle and
doing a hand injection.
The proper size umhrella 8' similar in structure to the
left umbrella 8 described above is loaded into the outer catheter
and passed into the left ventricle and opened by using the inner
catheter in the same manner as is carried out in closing the
atrial septal defect as described above. The opened umbrella 8'
is pulled snugly against the left side of the interventricular
septum adjacent to the ventricular septal defect.
The outer and inner catheters are then removed from the
body, leaving the obturator wire 3, and Silastic* tubing 3' is
passed over the guide wire 3 and subsequently into the heart
- 22 -
.
,; . ., .,. ~ . . . . .. .
53Q~a
to entirely cover the exposed guide wire 3.
By maintaining general pressure on the guide wire 3,
the umbrella 8' is held tightly against the left side of the
interventricular septum and thus closes the interventricular
septal defect. The umbrella 8' is maintained in place by the
barbs on the tips of the struts (like those described above) and
, - .,
by the obturator wire 3. ~dditionally the in~ernal blood pressure -
system, which is greater in the left ventricle than the right
(typically 90 min. Hg vs. 30 min. ~Ig), serves to help maintain the
umbrella 8' over the VSD, closing it off.
The Silastic* material 3' and the guide wire 3 are cut
off at the appropriate lengths to allow anchoring them in the
tissues of the right neck within the jugular vein. The incision
is closed, and periodic checks are made of the umbrella 8' over -
the subsequent 15 minutes by fluoroscopy.
The patient is anticoayulated prior to the installation
of the ventricular closing umbrella and is maintained on anticoagu-
lation therapy for several weeks. ~fter about six to eight wee}rs
and the umbrella 8' has been endothelialized, an incision is again -
made over the proximal end of the Silastic* material 3' and guide
wire 3 (~uite close to the original incision in the neck). The
~ guide wire 3 and Silastic outer covering 3' is isolated, and with
; the use of the "T"-piece 5 on the proximal end of the obturator
wire 3, the latter is unscrewed and removed from within the heart
and vascular system. The Silastic* material 3' is of course !`` ' '
removed simultaneously with the guide wire 3, and the incision
closed leavlng the VSD permanently closed.
Thus, the ventricular septal defect is closed with the
use of only a single umbrella 8' with temporary anchoring by the
guide wire 3 covered with the Silastic* material 3 to prevent
clotting and embolization.
- 23 -
'~
.
`` 1(~453~
To close a patent ductus arteriosus (PDA), for example
like that shown i.n Figure 14B, the same analogous method discussed
with respect to the ASD of Figure lB and the steps of Figures 9
A-K can be used. However, because of the longer distance between
the left and right outer walls of the PDA, modified aortic and
pulmonary umbrella elements 108, 109 are used in place of the left
and right umbrella elements 8, 9. The main modification is to
extend further out the male member of the aortic umbrella 108 or
alternatively the female member 194 (as illustrated in Figure 14C).
Othen~ise the structure of the umbrellas 108, 109 can be identical
to that disclosed in detail above with respect to the umbrellas 8,
9.
Finally, it is noted that it is advantageous to use the
closure structures of the present invention even when open-heart
surgery is necessary, as for example in the case of small babies.
In such cases, the closure structures of the present invention can
be applied through the open heart in a matter of a few minutes as
opposed to the typical thirty to forty minutes usually taken with
standard suturing of the shunt as practiced in the prior art.
- 24 -
,
" "
- Latest Septal Defect Closure System -
The first described embodiment of the closure
elements and the catheter operative elements and its method
of application described in detail with respect to Figures
lC - 11 were initially developed and experimentally tested
with dogs with success. Further development work has produced
the embodiment of Figures 16A-20 which is expected to be
applied to human patients in the very near future and which
will now be described in detail.
As shown in Figures 16A & ~ and 17A ~ B, for
e//~
an ASD there is provided two ~r~}e~ra-like closure elements,
a left one 308 and a right one 309, each havlng for example
six material supporting struts 381, 391, respectively.
The struts 381, 391 are made of a radiopaque
material (not necessarily metallic), for example stainless
steel, and as illustrated are initially flat in the radial
plane and then are twisted ninety degrees so that they are
then flat in the plane of the septum. The struts 381, 391
are hingedly attached to a central hub 384 and a sliding
sleeve 394, respectively, also made of for example stainless
steel. The surfaces of the hub 384 and the sleeve 394 are
grooved to hold the struts 381, 391.
~ ~ .
As noted above, thin Dacron, Teflon, nylon,
S; J~
~ila~tic, pericardium or silk, for example, can be used
for the umbrella sheet material 382, 392 ~hich is sutured
to the struts 381, 391, respectively.
The sliding sleeve 394 and the distal hub 384
are designed to lock securely together in opposed, facing
relationship by means of an internal, central, male-female
mechanism, as described above with respect to the previously
described embodiments (note for example Figure 11).
25 -
3~
Like the embodiment of Figuxe 12B, the struts 3Sl, 391 are de-
signed to be self-opening by the use of a resilient structure. In
the embodiment of Figures 16 and 17, this inherent resiliency is
provided by the addition of a thin, resilient, ~pringy ring 3~7,
397, of for example Silastic* material attached to the struts
which causes them to automatically spring out when they are no
longer constrained or under restraint. Suitable dimensions for
the ring 3~7, 397 for a umbrella-like closure element of two cm.
diameter is a ring h`aving an outer diameter of 8 mm. and a thick-
ness of 0.5 mm. The resilient members 387, 397 can take on
various forms besides a ring, such as for example a disc or
individual arms (not illustrated).
As before with respect to the embodiment of Figure 50 the
operative elements of the closure catheter system for the umbrella-
like closure elements of Figures 16 and 17 comprise several partso
(note Figures 18-20) an outer catheter 301, an inner, locking or
right atrial catheter 302, and an obturator wire 303. However, in
this later embodiment, the outer catheter 301 includes at its dis-
tal end a housing capsule 310 which is used to house both closure
elements 308, 309 as the catheter is inserted into the body in jux-
taposition to the septal defect to be closed. Additionally the
distal end of the inner, locking catheter includes a terminal
threaded portion 321 (in place of the distal hub 21 of inner cathe-
ter 2) which mates with a similarly threaded female orifice in the
sliding sleeve 39~, which allows positi~e, detachably fixed move-
ment of the right umbrella-like element 309 on the end of the inner
catheter 302. At the proximal end of the inner catheter 302, there
is pro~ided a "manipulating-stop" hub 302' which prevents the
proximal end of the inner catheter from going into the outer
~catheter 301 and allows the inner catheter 302 to be easily
manipulated for the twisting, pushing or pulling thereof.
- 26 -
'''~ .
536D~
As before, the lef~ umbrella-like element 308 is
detachably fix~d by threaded engagement to the threaded portion
331 on the distal end of the obturator wire 303. As illustrated
in Figure 19, the terminal distal section of the obturator wire
301 can include a built-up portion 301' for strengthening purposes.
The method of application of the embodiment of Figures
16 - 20 is similar to that disclosed with resipect to Figures
9A - 9K except that the closed umbrella-like closure elements
308, 309 fastened to the distal ends of the obturator wire 303
and the inner catheter 302, respectively, are both initially
placed in line in the distal capsule 310~ The loaded capsule 310
then is inserted;through the body in juxtaposition to the
septal defect in the position analogous to that shown in
Figure 9A. The left closure element 308 is pushed out of the
capsule 310 until it is clear thereof, at which point the
struts 381 automatically open under the spring action of the
resilient ring 387. The outer catheter 301 is then pulled
back into the right atria,and the open closure element 308
gently pulled snugly against the left atrium septum (analogous
to the action illustrated in Figure 9E).
Once the left closure element 308 is firmly in position,
the right closure element 309 by means of the inner catheter 302
is moved out of the distal capsule 310 until it is clear thereof,
at which point the struts 391 automatically open under the
spring action of the resilient ring 397. The inner catheter 302
with the open right closure element 309 on the end thereof is
pushed further forward, riding over the obturator wire 303 and
forcing the sliding sleeve 394 of the right closure element 309
to slide onto the left closure element hub 384, locking the two
together (analogous to the action illustrated in Figure 9H).
- 27 -
.! 1:,
3~
Once the umbrella-like elements 308, 309 are locked
in place, the obturator wire 301 and the inner catheter 302
can be unscrewed from them and,with the outer catheter 301,
completely withdrawn from the body. To insure that the closure
elements 308, 309 are securely locked, the inner catheter
302 is unscrewed first and the two umbrella-like structures308, 309
moved to-and-fro b means of the obturator wire 303 and the
,~.,"., ~J6,~ 0 ~0,
action viewed by ~e~y.
Other than the differences in structure and method
outlined above, the two embodiments are at least generally the
same and reference is had to the more detailed description of
the embodiment of Figures lC - 11 for further detailed under-
standing of the embodiment of Figures 16 - 20.
Thus atrial septal defects ~Figure 1) and in similar
fashion ventricular septal defects (Figure 13) and great vessel
shunts (Figure 14) are closed by non-invasive techniques. The
closure catheter system of the present invention is efficient
and with proper caution is safe.
From past experience with cardiac surgery, stainless
steel, particularly of the 300 series, which is the pr~ferred
materials for all structural parts remaining in the heart, and
materials such as Dacron, Teflon, nylon~ percardium, Silastic
and silk can be permanently inserted within the heart and
tolerated without adverse effects. It is estimated that the
heart will endothelialize the closure elements within six to
eight weeks as occurs after standard shunt closures using
open-heart surgery.
Because many varying and different embodiments may
be made within the scope of the inventive concept herein taught,'
and because many modifications may be made in the embodiments
herein detailed in accordance with the descriptive requirements
of the law, it is to be understood that the details herein are
to be interpreted as illustrative and not in a limiting sense.
- 28 -
