U.S. patent number 3,874,388 [Application Number 05/331,559] was granted by the patent office on 1975-04-01 for shunt defect closure system.
This patent grant is currently assigned to Alton Ochsner Medical Foundation. Invention is credited to Terry D. King, Noel L. Mills.
United States Patent |
3,874,388 |
King , et al. |
April 1, 1975 |
SHUNT DEFECT CLOSURE SYSTEM
Abstract
A method and apparatus for closing off a septal defect or shunt
in the intravascular system or the great vessels including a pair
of opposed, umbrella-like elements locked together in face-to-face
relationship on opposite sides of the septal defect, thereby
closing it. The dual umbrella-like closure elements are
sequentially applied and joined together via an outer catheter
inserted into the interior of the heart by means of the jugular
vein in the neck or a vein in the groin along with other associated
operative elements used within the outer catheter, thereby
eliminating the need for open-heart surgery to correct a septal
defect or shunt as was heretofore required. For a ventricular
septal defect a single umbrella-like element is used which is
temporarily held in place by an operative element which is
subsequently removed.
Inventors: |
King; Terry D. (New Orleans,
LA), Mills; Noel L. (New Orleans, LA) |
Assignee: |
Alton Ochsner Medical
Foundation (New Orleans, LA)
|
Family
ID: |
27507254 |
Appl.
No.: |
05/331,559 |
Filed: |
February 12, 1973 |
Current U.S.
Class: |
606/232;
606/213 |
Current CPC
Class: |
A61B
17/0057 (20130101); A61M 25/00 (20130101); A61B
2017/00619 (20130101); A61B 2017/00575 (20130101); A61B
2017/00606 (20130101); A61B 2017/00588 (20130101) |
Current International
Class: |
A61M
25/00 (20060101); A61B 17/00 (20060101); A61F
2/24 (20060101); A61b 017/04 () |
Field of
Search: |
;128/334R,335,348,351,1R
;138/89,91,92,93,94 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Hunter et al., - Annals of Surgery - Feb. 1970, Vol. 171, No. 2,
pp. 315-320. .
King et al., - Surgery - Dec. 1953, Vol. 34, pp. 1100-1116. .
Hufnagel et al., - The Bulletin - Georgetown Med. Cen. (Vol. IV,
No. 5, pp. 137-139) 1951. .
Mills et al., - Supplement I to Circulation, (Vols. XLIII and XLIV,
pp. 1-111), 5/1971..
|
Primary Examiner: Truluck; Dalton L.
Attorney, Agent or Firm: Pugh & Laiche
Claims
What is claimed as invention is:
1. A shunt defect closure apparatus for closing off a shunt defect
in the septum of for example the intravascular system
comprising:
mechanical expansion means having an initial size substantially
smaller than the diameter of the shunt defect to be closed during
its preliminary handling and a final size substantially larger than
the diameter 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 a dual
set of umbrella-like structures for placement on opposite sides of
the shunt defect, the umbrella-like structures having central hub
means for connecting said dual set of umbrella-like structures
together through the shunt, each said umbrella-like structures
including a series of relatively hard, strut-like members emanating
out from said central means in at least a generally perpendicular,
radial direction when said expansion means is in its final size and
in at least a generally parallel, axial direction when said
expansion means is in its initial size; and
operative means removably connected with said expansion means for
at least temporarily holding the said expansion means on to the
shunt defect after at least one of said umbrella-like structures
has been expanded out to its final size.
2. The apparatus of claim 1 wherein said umbrella-like structure
comprises a series of supporting struts with flexible material
suspended between said struts, said struts being moveably attached
to a centrally located support element for movement from a closed
position to an open position or vice versa.
3. The apparatus of claim 1 wherein said operative means includes
an obturator wire having attaching means at it distal end for
temporarily attaching said obturator wire to one of said
umbrella-like structures
4. The apparatus of claim 3 wherein said operative means further
includes an outer catheter serving as a conduit for placing both
said umbrella-like structures through the body adjacent to the
shunt, said outer catheter having a diameter substantially greater
than said obturator wire, said one of said umbrella-like structures
being transported through said outer catheter by means of being
mounted on the distal portion of said obturator wire and pushing
said obturator wire with said one of said umbrella-like structures
means thereon through said outer catheter.
5. The apparatus of claim 1 wherein each said umbrella-like
structures includes an expanse of relatively flexible material
extending between said strut-like members to thereby at least
substantially close off the spaces between said strut-like
members.
6. The apparatus of claim 1 wherein said umbrella-like structures
have their undersides in opposing relationship to each other and
said strut-like members are made of resilient material and
resiliently bear inwardly toward the opposing umbrella-like
structure, thereby securing the opposing umbrella-like structures
to the septum.
7. The apparatus of claim 1 wherein said strut-like members include
at their distal tips barb-like means emanating from their underside
in a direction at least generally perpendicular thereto for bearing
against the septum when each of said umbrella-like structures is
moved toward the septum.
8. The apparatus of claim 1 wherein said operative means includes
an obturator wire having attaching means at its distal end for
temporary connection to one of said umbrella-like structures and
wherein said first one of said umbrella-like structures has a
central hub having a connection for temporary connection to said
obturator wire; and wherein said second umbrella-like structure has
a central sleeve which can slide over said obturator wire, said
central hub and said central sleeve having locking means for
locking them together in opposing fashion when on opposite sides of
the shunt.
9. The apparatus of claim 8 wherein said locking means comprises a
male-female connection between said central hub and said central
sleeve, the exterior of said connection means of said central hub
forming the male member and the interior of said sleeve forming at
least in part the female orifice.
10. The apparatus of claim 9 wherein said male member includes a
projection on its mating surface and said female orifice includes
an indentation for further mating with said projection and locking
the hub and sleeve together.
11. A shunt defect closure apparatus for closing off a shunt defect
in the septum of for example the intravascular system
comprising:
mechanical expansion means having an initial size substantially
smaller than the diameter of the shunt defect to be closed during
its preliminary handling and a final size substantially larger than
the diameter 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 forcing the distal, end portions
of the underside of said umbrella-like structure against the septum
to at least partially close the shunt, said umbrella-like structure
being of a material that will be endothelialized into the septum;
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 associated with said expansion means for at least
temporarily holding said expansion means on to the shunt
defect.
12. The apparatus of claim 11 wherein the underside of said
umbrella-like structure has on its distal portions bearing means
for bearing against the septum, the bearing direction being
generally perpendicular to the main surface of said umbrella-like
structure and hence parallel to the central axis of the shunt.
13. The apparatus of claim 11 wherein said umbrella-like structure
in its final size includes a series of relatively hard strut-like
members radially emanating out from said extended central means in
a direction at least generally perpendicular thereto, the distal
tips of said strut-like members including barb-like structures
emanating in a direction at least generally perpendicular thereto,
said barbs serving as said bearing means.
14. The apparatus of claim 11 wherein said umbrella-like structure
includes an expanse of relatively flexible material extending
between said strut-like members to thereby at least substantially
close off the spaces between said strut-like members.
15. The apparatus of claim 11 wherein said strut-like members are
made of resilient material and resiliently bear inwardly toward the
septum when the umbrella-like structure is in its final size,
thereby securing the umbrella-like structure to the septum.
16. A shunt defect closure apparatus for closing off a shunt defect
in the septum of for exammvTHE INTRAVASCULAR system comprising:
mechanical expansion means having an initial size substantially
smaller than the diameter of the shunt defect to be closed during
its preliminary handling and a final substantially larger than the
diameter 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
expansion structure being of a material that will be
endothelialized into the septum and having an extended, main body
with a facing side for contacting the septum surface around the
shunt and being extended at least in part in a direction at least
generally parallel to the septum surface, and extended central hub
means centrally located within said main body and being extended in
a direction at least generally perpendicular to the septum surface
for having pressure applied to it along its extended direction for
forcing the distal, end portions of the facing side of said
expansion structure against the septum to at least partially close
the shunt, the facing side of said expansion structure having on
its distal portions anchoring means for anchoring said expansion
structure to the septum, when said expansion structure is forced
against the septum, said anchoring means comprising projections
extending at least partially in a direction parallel to said
extended central means and hence parallel to the central axis of
the shunt and perpendicular to the septum surface.
17. The apparatus of claim 16 wherein said expansion structure is
an umbrella-like structure having a series of relatively hard
strut-like members radially emanating from said extended central
means, and having projections at their distal ends, said
projections being barb-like structures emanating in a direction at
least generally perpendicular to the emanating direction of said
strut-like members.
18. The apparatus of claim 17 wherein said umbrella-like structure
includes an expanse of relatively flexible material extending
between said strut-like members to thereby at least substantially
close off the spaces between said strut-like members.
19. The apparatus of claim 17 wherein said strut-like members are
made of resilient material and resiliently bear inwardly toward the
septum when the umbrella-like structure is in its final size,
thereby securing the umbrella-like structure to the septum.
20. The method of closing off a ventricular septal defect in the
intravascular system comprising the following sequential steps:
a. providing a ventricular septal defect closure structure for
closing off the ventricular septal defect comprising mechanical
expansion means having an initial size substantially smaller than
the diameter of the intravascular shunt defect to be closed and a
final size substantially larger than the diameter of the septal
defect for positioning over and across the septal defect to
permanently close it off after being expanded to its larger size,
said expansion means being made of a tissue compatible material
which can be endothelialized into the septum; and operative means
associated with said expansion means for at least temporarily
holding the said expansion means on to the defect, said operative
means incuding an obturator wire having attaching means at its
distal end for temporarily attaching said obturator wire to said
expansion means;
b. making a relatively small, minor incision or opening in the body
and into a vein having access to the ventricle with the defect;
c. introducing the obturator wire with said closure structure
attached to its distal end while in its smaller size into said
opening and through the septal defect;
d. expanding said expansion means of said closure structure to its
larger size;
e. using said obturator wire to position and attach said expansion
means of said closure structure while in its larger size over and
across the far side of the septal defect, closing the septal
defect;
f. closing off said opening in the body with said obturator wire
still attached to said expansion means;
g. allowing said expansion means of said closure structure to
become endothelialized over a substantial period of time, further
closing off the septal defect;
h. reopening the opening in said body and removing said obturator
wire; and
i. permanently closing off said opening; whereby the shunt is
permanently closed by substantially non-invasive or at least
limitedly evasive techniques and without the substantial suturing
of the shunt as practiced in the prior art.
21. The method of claim 20 wherein in step (b) the vein used for
the opening is the external or internal jugular vein and the
incision is made in the neck.
22. The method of closing off a shunt defect in the septum of for
example the intravascular system comprising the following
steps:
a. providing a shunt defect closure-structure for closing off the
shunt defect comprising mechanical expansion means having an
initial size substantially smaller than the diameter of the
intravascular shunt defect to be closed and a final size
substantially larger than the diameter of the shunt defect for
positioning 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 the side of the shunt, said umbrella-like structure including a
central hub having a series of relatively hard, strut-like members
emanating out from said central hub in at least a generally
parallel, axial direction when said expansion means is in its
initial size and a generally perpendicular, radial direction when
said expansion means is in its final size, said umbrella-like
structure being made of a tissue compatible material which can be
endothelialized into the septum; and operative means associated
with said expansion means for at least temporarily holding the said
expansion means on to the shunt defect;
b. making an opening in the body;
c. introducing said closure structure while in its smaller size in
proximity to the shunt to be closed by means of said opening;
d. expanding said umbrella-like structure of said closure structure
to its larger size by expanding out said strut-like members;
e. permanently positioning and attaching said umbrella-like
structure of said closure structure while in its larger size over
and across the shunt, closing the shunt;
f. allowing said umbella-like structure of said closure structure
to become endothelialized, further closing off the shunt; and
g. ultimately closing off said opening; whereby the shunt is
permanently closed by substantially non-invasive or at least
limitedly evasive techniques and without the substantial suturing
of the shunt as practiced in the prior art.
23. The method of claim 22 wherein in step (b) the opening in the
body is made by making a relatively small, minor incision to gain
access to a vein or artery of the blood circulatory system; and
wherein in step (c) the introduction is made through said vein or
artery.
24. The method of claim 22 wherein in step (a) in providing said
expansion means there is further included the providing of a second
umbrella-like structure having the same claimed features as the
first umbrella-like structure for placement on the opposite side of
the shunt from said first umbrella-like structure and steps (c)
through (d) inclusive are each repeated for said second
umbrella-like structure.
25. The method of claim 24 wherein in step (a) said operative means
are provided by providing an outer catheter having a
cross-sectional area smaller than the shunt and an obturator wire
having a diameter substantially smaller than said outer cathether;
and wherein in step (b) the opening in the body is made by making a
relatively small minor incision to gain access to a vein or artery;
and wherein in step (c) the introduction is made through said vein
or artery and includes the following steps:
i. inserting said outer catheter through the incision into and
through the vein/artery until its distal end is in juxtaposition to
the shunt and, for said first umbrella-like structure, is passed
through the shunt but, for the second umbrella-like structure, is
located on the proximal side of the shunt; and
ii. moving said umbrella-like structures out of the distal end of
said outer catheter.
26. The method of claim 25 wherein in step (c) there is further
included in sub-step (ii) the steps of:
attaching said first umbrella-like structure to the distal end of
said obturator wire and inserting the obturator wire with said
first umbrella-like structure attached thereto in its initial size
into and through the outer catheter until said first umbrella-like
structure has emerged out of the distal end of said outer
catheter;
and wherein the step (e) the underside of said first umbrella-like
structure is pulled against the distal side of the septum.
27. The method of claim 25 wherein in step (a) in providing said
second umbrella-like structure there is further included the
providing of a central sleeve with a central orifice having a
diameter greater than said obturator wire but less than said outer
catheter; and wherein in step (c) there is further included in
sub-step (ii) the steps of:
sliding said central sleeve of said second umbrella-like structure
over said obturator wire and passing said second umbrella-like
structure through said outer catheter while in its initial size
until said second umbrella-like structure has emerged out of the
distal end of said outer catheter;
and wherein in step (e) the underside of said second umbrella-like
structure is pushed against the proximal side of the septum.
28. The method of claim 27 wherein in step (a) additional operative
means are provided by providing a second, inner catheter having a
diameter smaller than said outer catheter and having a central
longitudinal opening along its length of a diameter larger than the
diameter of said obturator wire and being slidable thereon and
having a tip at its distal end; and wherein, in the step (e) for
said second umbrella-like structure, the underside of said second
umbrella-like structure is pushed against the proximal side of the
septum by pushing the tip of said inner catheter against the
central sleeve of said second umbrella-like structure.
29. The method of claim 28 wherein in step (a) the central hub of
said first umbrella-like structure is provided with a centrally
located, locking male member, the center of which serves as the
connecting means for attaching the central hub to the distal end of
the obturator wire; and wherein, the step (e) for said second
umbrella-like structure, said inner catheter is used to push the
central sleeve of said second umbrella-like structure so that its
orifice, which then serves also as a female member, is pushed into
the locking male member of said first umbrella-like structure,
locking the two umbrella-like structures together.
30. The method of claim 28 wherein in step (a) the strut-like
members of said second umbrella-like structure are provided with a
set of elevating struts hingedly connected at one end to the
strut-like members at a point removed from said central sleeve and
at the other end to a centrally located, leading and elevating
member; and wherein, in the step (d) for said second umbrella-like
member, said second umbrella-like structure is expanded by pushing
said central sleeve toward said elevating member by means of said
inner catheter, causing said elevating struts to push said
strut-like members out away from said central sleeve.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an intravascular method and
apparatus for closure of septal defects or shunts 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 working within said outer
catheter.
2. 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 vertrucles by the
interventricular 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 interventricular septal defects or patent
ductus arteriosus and aorthico-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 shunts such as occur in patent ductus
arteriousus 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 effects 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 arteriosus. 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 intracardiac 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. The 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 was still required. See
for example "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 Interventricular 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 only possible to
repair septal defects or shunts through open-heart surgery,
involving shunting the blood through an artificial 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 excellent 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 require only a small incision over a vein in the
groin or neck under only local anesthesia, such as is carried out
for many routine cardiac catheterizations.
Moreover, the catheter/closure system of the present invention
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 procedure, 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 elements, 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 into a
body cavity, naturally or surgically opened. Several different
catheters have been developed in the past, either for experimental
research purposes or clinical application. The Mobin-Uddin catheter
is one that is used for partial occlusion of the inferior vena cava
to prevent pulmonary embolization. This catheter has been described
in a publication by Drs. Kazi Mobin-Uddin and James R. Jude in an
article entitled "A 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.
Pat. No. 3,540,431 to Dr. Kazi Mobin-Uddin issued Nov. 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" by
Hunter, et al., Annals of Surgery, Vol. 171, No. 3, Pp. 315-320,
February 1970.
Additionally, in experimental work performed by one of the
co-inventors hereof, 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 Ventricular Septal Defect," Supplement I to
Circulation, Vols. XLIII and XLIV, page I-111, May 1971. See also
the article by Dr. Harold King et al., entitled "Experimental
Surgical Repair of Ventricular Septal Defects," SURGERY, Vol. 34,
pp. 1,100 - 1,116, 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:
Patent No. Inventor(s) Title Issue Date
__________________________________________________________________________
2,493,326 J. H. Trinder "Tampon For Control 1/30/50 of Intractable
Nasal Hemorrhages" 2,799,273 V. J. Oddo "Haemostatic Catheter"
7/16/57 3,334,629 B. D. Cohn "Occulsive Device 8/8/67 For Inferior
Vena" 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 Defective Natural Heart
Valve"
__________________________________________________________________________
However, as should be fully appreciated and understood from the
detailed description of the preferred embodiments below, all of
these diverse prior art catheters and umbrella-like elements,
neither collectively nor individually, anticipate or make obvious
the present, pioneering and far-reaching invention.
BRIEF DESCRIPTION OF THE DRAWINGS
For a further understanding of the nature and objects 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:
FIG. 1A is a schematic illustration of the heart, partially cut
away, showing the applied closure structure of the present
invention closing off an atrial septal defect with two of the
catheter operative elements of the catheter/closure system of the
present invention being withdrawn; while
FIG. 1B is similar in perspective to FIG. 1A showing a typical
atrial septal defect (ASD) prior to the application of the present
invention.
FIG. 1C is a perspective view of the left and right umbrella-like
closure elements used for an ASD in their open or erected
positions;
FIG. 2A is a side view of the left umbrella-like closure element of
the present invention in its collapsed position with the inner,
central hub shown in phantom lines; while
FIGS. 2B and 2C are side, cross-sectional and end views,
respectively, of the inner, central hub of the left umbrella-like
closure element of FIG. 2A;
FIG. 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 partially in phantom lines; while
FIGS. 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 FIG. 3A;
FIG. 4 is a side view of a typical strut element used in the left
and right umbrella-like closure elements of the present
invention;
FIG. 5 is a perspective view of three of the catheter operative
elements, concentrically assembled together, which are used in the
method of the present invention;
FIG. 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 thereof
partially opened, portions of the umbrella-like element,
particularly the covering material, not being illustrated for
simplicity purposes; while
FIG. 7 is similar to FIG. 6 with the exception of showing the right
umbrella-like closure element being affixed to the central one of
the catheter operative elements and showing an additional operative
element, a control disc, positioned on the proximal end of the
central catheter operative element;
FIG. 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;
FIGS. 9A through 9K are side, schematic views of the inner heart
structure illustrating the sequential steps of the method of the
present invention as being applied to the closing of an atrial
septal defect (ASD); while
FIGS. 10A and 10B are right and left end views, respectively, of
the umbrella-like closure elements of the present invention after
being applied and locked together to close off the artrial septal
defect;
FIG. 11 is a side, cross-sectional view of the central hub and
sleeve structures of the left and right umbrella-like closure
elements locked together in a male-female relationship;
FIGS. 12A and 12B are side, cross-sectional and side, perspective
views, respectively, of two other structures allowing two other
alternative methods of opening or erecting the umbrella-like
structure of the right umbrella-like closure element;
FIG. 13A is a schematic illustration of the heart, partially cut
away, showing the applied closure structure of the present
invention closing off a ventricular septal defect with an alternate
method utilizing a single umbrella-like element being used;
while
FIG. 13B is similar in perspective to FIG. 13A showing a typical
ventricular septal defect (VSD) prior to the application of the
present invention.
FIG. 13C is a perspective view of the single umbrella-like closure
element used for a VSD in its open or erected position; while
FIG. 13D is a side view of the special obturator wire used in the
alternative single umbrella technique;
FIG. 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
final catheter operative element of the catheter/closure system of
the present invention ready to be withdrawn; while
FIG. 14B is similar in perspective to FIG. 14A showing a typical
patent ductus arteriosus (PDA) prior to the application of the
present invention.
FIG. 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;
FIG. 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
FIG. 15B is a side view of the embodiment of FIG. 15A as it is
being applied to the shunt and being pushed t o its locking
position with the left umbrella-like element; while
FIG. 15C is a close-up, side view of the central portions of the
umbrella-like closure elements in their final, locked position.
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 it must meet the several stringent mechanical
requirements placed upon it, must reliably open at the desired time
and place, and must effect a suitably tight closure of the defect
or shunt in the heart system for a long period of time without any
deterioration and without producing any unwanted side-effects
either on tissue or blood. Many mechanical 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 closure structure of the preferred embodiment of the present
invention, as illustrated in FIGS. 1C, 2 and 3, comprises a pair of
opposed, umbrella-like elements 8, 9, a right 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 FIG. 4). Each
strut 81, 91 has for example a length of 5.35 mm, with a 60.degree.
angle between the struts 81, 91. The struts 81, 91 are made of a
radiopaque material (not necessarily metallic), for example
stainless steel, which have at the distal ends thereof small
projections or barbs 83, 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 86', 96'; tie eyes 87a, 97a for raising or
lowering the struts 81, 91 by means of ties or lines 7; and suture
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 through 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 FIGS. 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 structures. 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 90.degree.. 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
application, as described more fully below.
Thin Dacron, Teflon, nylon, silastic, pericardium or silk, for
example, routinely used to be 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 of sufficient strength and
resiliency to open and close smoothly. Although the umbrella
material 82, 92 could be fanfolded between 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, 9. 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 relationship by means of an
internal, central, male-female mechanism (note particularly FIG.
11). A typical structure for achieving this is illustrated
particularly in FIG. 11 with supplemental reference to FIGS. 2B and
3B. The hub 84 includes a small 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.
To total external diameter of the hub 84 is for example 3.3 mm.,
and it has been engineered with grooves 89 so that the struts 81
are recessed within the surface and 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 for example approximately 0.075 mm. The proximal end of
the hub 84 is relatively blunt and has a central threaded orifice
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 1; 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 FIGS. 5, 7, 8 and 9J.
The outer, thin wall catheter 1, for example a No. 24 inch 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 made
from thin wall, woven Dacron or preferably polyvinyl material and
has a gentle curve at the cardiac end to allow easy manipulation
through a septal defect in the cardia area.
As shown in FIG. 5, inside the outer, thin wall catheter 1 is a
second, radiopaque, inner catheter 2 which could be for example a
No. 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. The inner catheter 2 should be of a size to be quite mobile
through the outer catheter 1.
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. A removable, proximal T-piece 5
(note FIG. 9J) is used for rotational manipulation 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 1 mm. so that it may 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 FIG. 7, a control disc 6 is provided for ease in
manipulating and controlling the ties or suture lines 7. The 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
FIG. 8. The loading cone 4 is provided to assist in the easy
loading or insertion of the umbrella-like elements 8, 9 into the
outer catheter 1. For example, as shown in FIG. 8, the left
umbrella 8 threaded, onto 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 catheter 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 once locked in place is only approximately 3.5 mm. The
umbrella-like elements can be produced in diameter sizes of for
example 10mm., 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 FIG. 12A the
struts 91' of the right umbrella can be mechanically 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 FIG. 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 embodiment of the right
umbrella is shown in FIGS. 15A-C in which the necessity of a tie
wire system is eliminated. The umbrella 209 is similar in general
structure to the right umbrella 9 except that in place of the tie
wire system there is included a set of elevating struts 219'
hingedly attached between the regular umbrella struts 291 and the
elevating sleeve 294'. As shown in FIG. 15B, as the elvating 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 FIG. 15C.
Finally, although an umbrella-type structure is thought to be
particularly effective, other expansion systems i.e., the elements
which initially have a relatively 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 inflatable
structure(s) could be used.
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 particular reference to FIGS. 1A-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 FIG.
1B. Once confirmed, sizing of the ASD 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 FIG. 5), i.e., elements
1, 2 and 3, the latter having the left umbrella 8 attached to its
threaded end 31, is then inserted via the femoral vein into the
heart under continuous flouroscopic control into the right atrium.
With further advancing of the catheter assembly, it is placed in
the left atrium (note FIG. 9A).
By manipulating the obturator wire 3, the distal hub 84 carrying
the collapsed left umbrella 8 is advanced beyond the outer, thin
wall catheter 1 into the left atrium (FIG. 9B). Once the left
umbrella 8 is pushed beyond the tip of the outer, thin wall
catheter 1, the umbrella 8 is initially unfolded by pushing the
inner catheter 2 against the struts 81 and holding fast the
obturator wire 3 (FIG. 9C), expanding the umbrella out in excess of
the diameter of the outer catheter 1.
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 90.degree. position (FIG. 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 (FIG. 9E).
Once the left umbrella 8 is firmly fixed, the inner catheter 2 is
withdrawn and removed and the right umbrella 9 slid into the
obturator wire 3 and loaded into 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 FIG. 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 (FIG. 9F). At this point the outer catheter 1 is
withdrawn to allow the right umbrella 9 to lie freely upon the
obturator guide wire 3 within 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 (FIG. 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 (FIG.
9H). A clicking sensation is felt through the obturator wire 3, and
a click can be heard as the umbrellas 8. 9 are locked in place.
Once in place the umbrellas 8. 9 are tugged gently with the
obturator 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 (FIG. 9J). The obturator guide wires 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 (FIG. 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 appropriate angiograms,
dye curves 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 6 to 8
weeks, and be thereby integrated into the heart's structure.
After completion of the operation, the vein and inguinal incision
are closed.
Additional Methods of Application
For purposes of further illustration and disclosure, the method of
application of the present invention will now be described in some
detail with respect to the closing of a ventricular septal defect
(VSD) with particular reference to FIGS. 13 A-C.
In order to gain access to the heart, an incision is made in the
right neck over the external or internal jugular vein under local
anesthesia. The jugular vein is isolated and venotomy is made for
insertion of the outer catheter 1. Standard catherization
techniques are then utilized to confirm the presence of the VSD
such as the one shown in FIG. 13 B. Once confirmed, sizing of the
VSD is then achieved by means of special but standard balloon
catheters, and the appropriate size of the left umbrella-like
closure element 8' is selected.
The outer catheter is inserted into the vein and subsequently
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 NIH catheter
through the outer catheter into the left ventrical and doing a hand
injection.
The proper size umbrella 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 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.
Additionally the internal blood pressure system, which is greater
in the left ventricle than the right (typically 90 min. Hg vs. 30
min. Hg), 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 anticoagulated prior to the installation of the
ventricular closing umbrella and is maintained on anticoagulation
therapy for several weeks. After about 6 to 8 weeks 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
(quite 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
leaving 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.
To close a patent ductus arteriosus (PDA), for example like that
shown in FIG. 14B, the same analogous method discussed with respect
to the ASD of FIG. 1B and the steps of FIGS. 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 FIG. 14C). Otherwise 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 30 to 40 minutes usually taken with standard
suturing of the shunt as practiced in the prior art.
Thus atrial septal defects (FIG. 1) and in similar fashion
ventricular septal defects (FIG. 13) and great vessel shunts (FIG.
14) are closed by non-invasive techniques. The closure catheter
system of the present invention is efficient and with proper
caution is safe. The addition of the opening and retracting ties 7,
7' greatly increases the safety of the device. Although it has not
yet been found to be necessary to use the retracting eyes or holes
87a and ties for the left struts 81, they may be used if
desired.
From past experience with cardiac surgery, stainless steel,
particularly of the 300 series, which is the preferred material 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 6 to 8 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.
* * * * *