United States Patent [19]
`Balko et al.
`.
`
`[11] Patent Number:
`[45] Date of Patent:
`
`4,512,338
`Apr. 23, 1985
`
`[54] PROCESS FOR RESTORING PATENCY TO
`BODY VESSELS
`[76] Inventors:
`
`Alexander B. Balko, 30 Red Barn
`La., East Greenwich, RI. 02818;
`Dhiraj M. Shah, RD. #1, Rte. 43,
`Rensselaer, NY. 12144
`[21] Appl. No.: 460,842
`[22] Filed:
`Jan. 25, 1983
`
`[51] Int. Cl.3 .................... .. A61M 29/00; A61B 19/00
`[52] US. Cl. ................................ .. 128/1 R; 128/341
`[58] Field of Search ................... .. 3/l.4; 128/341, 343,
`128/345; 604/8; 128/1 R
`References Cited
`U.S. PATENT DOCUMENTS
`
`[56]
`
`3,868,956 3/1975 Al?di et al. ....................... .. 128/345
`4,170,990 10/1979 Baumgart et al. ..
`.. 128/92 B
`4,425,908 1/1984 Simon ................................ .. 128/325
`Primary Examiner-—C. Fred Rosenbaum
`Assistant Examiner-C. W. Shedd
`
`Attorney, Agent, or Firm—Robert J. Doherty
`[57]
`ABSTRACT
`A process in which a shape memory alloy such as niti
`nol wire which has been previously fabricated in its
`parent phase to form a longitudinally oriented coil of
`adjacent wire loops and thereafter cooled to its martens
`ite phase and reshaped to a relatively straight shape, is
`utilized as an intra-luminal device to reinforce or re
`place a weakened or otherwise damaged vessel. The
`reformable wire is inserted into the vessel in such a
`manner to be temperature insulated such that upon the
`removal of the insulation means, the wire reforms to its
`coil shape so as to be urged against the internal walls of
`the damaged vessel and supplies a patent channel
`through which body fluids may pass. In this manner,
`removal of the damaged portion of the vessel with the
`attachment of graft material as a replacement thereto
`along with the complex surgical techniques required to
`perform such is avoided.
`
`15 Claims, 8 Drawing Figures
`
`as». ,1 W.
`
`l l
`l1 l1
`
`Edwards Exhibit 1031, p. 1
`
`

`

`US. Patent
`
`Apr. 23, 1985
`
`4,512,338
`
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`Edwards Exhibit 1031, p. 2
`
`

`

`1
`
`4,512,338
`
`PROCESS FOR RESTORING PATENCY TO BODY
`VESSELS
`
`BACKGROUND AND OBJECTS OF THE
`INVENTION
`This invention deals with improved methods of treat
`ing defects in body vessels. It has use in patient trauma
`caused by a gunshot wound, stabbing, etc. or where the
`vessel (artery, vein, or other body passage) is perforated
`or disrupted. It is also particularly adapted but not lim
`ited to reconstruction of an abdominal aortic aneurysm.
`Presently such aneurysms are surgically corrected by
`the re-section thereof with accompanying installation of
`a replacement graft. Generally this graft is of a Dacron
`material constructed in longitudinally expandible tubu
`lar form and is surgically connected between the re
`maining portion of the aorta and the left and right iliac
`arteries. Such procedure is in detail described in an
`article set forth on FIGS. 1 through 20, Pages 231
`through 233 entitled “Resection of Abdominal Aortic
`Anerurysm” published in the Atlas of Surgical Opera
`tions, 4th ed. R. M. Zollinger and R. M. Zollinger, Jr..
`Such procedure is time consuming, requires high skill
`and involves a signi?cant amount of patient risk. Ac
`cordingly, it would be highly desirable to replace such
`technique with a simpler, less traumatic procedure
`which is, accordingly, the primary object of the present
`
`15
`
`20
`
`25
`
`invention.
`_
`These and other objectives of the present invention
`are accomplished by the use of a wire alloy coil for
`having shape memory characteristics. The wire in non
`coil form is positioned in the weakened vessel such that
`upon reformation by an increase in temperature to the
`coil form enables the coil to bridge the weakened vessel
`portion so as to form a substitute vessel wall portion in
`that defective area. More speci?cally, the process in
`volves a reduced or non-surgical restoration of the
`patency of a hollow body vessel which includes a local
`ized defect disposed intermediate ?rst and second po
`tent vessel portions, comprising inserting at least the
`front end of a continuous length of shape-memory alloy
`wire which has been previously fabricated in its parent
`phase to form a longitudinally oriented coil of adjacent
`wire loops and then cooled to its martensite phase and
`reshaped to a relatively straight length along the inte
`rior of said vessel past said defect to a position adjacent
`the ?rst potent vessel portion while maintaining the
`temperature of said wire below its martensite transfor
`mation point and thereafter heating said wire to its
`transformation point progressively from the front
`thereof to the rear thereof so as to initially cause the
`thus reshaped wire loops of the front wire end to be
`urged against the interior of said first potent vessel
`portion so as to be at least temporarily positioned
`thereat and thereafter cause the reformation of the re
`mainder of said coil so as to bridge said localized defect
`and into position adjacent said second potent vessel
`portion.
`Other objects, features and advantages of the inven
`tion shall become apparent as the description thereof
`proceeds when considered in connection with the ac
`companying illustrative drawing.
`
`35
`
`45
`
`50
`
`55
`
`65
`
`2
`DESCRIPTION OF THE DRAWING
`In the drawing which illustrates the best mode pres
`ently contemplated for carrying out the present inven~
`tlOn:
`FIG. 1 is a partial sectional view showing the restora
`tion of a body vessel, namely, the aorta having an aneu
`rysm therein with the procedure and devices of the
`present invention in an initial stage;
`FIG. 2 is a view similar to FIG. 1 but showing an
`intermediate stage after the wire has been heated and
`has started to form a coil;
`FIG. 3 shows the completed procudure;
`FIG. 4 is a partial sectional view taken through line
`4—-4 of FIG. 3;
`FIG. 5 is a view similar to FIG. 1 but showing a
`modi?ed form of the invention wherein a fabric graft is
`not utilized;
`FIG. 6 is a view similar to FIG. 2 but showing an
`intermediate step in the procedure shown in FIG. 5;
`FIG. 7 is a partial sectional view of another form of
`the invention in a partially completed stage; and
`FIG. 8 is a view similar to FIG. 7 but showing the
`completed repair structure.
`
`DESCRIPTION OF THE INVENTION
`Turning now to the drawing and more particularly
`FIGS. 1 through 3, 5, and 6 thereof, the present inven
`tion will be explained in relationship to the repair of an
`aortic aneurysm. It should be brought out, however,
`that the present invention has utility not only as a rein
`forcement of a weakened arterial wall such as the aortic
`aneurysm shown but also in the restoration of patency
`to previously narrowed, weakened, ballooned, or other
`wise defective or imparied lumen or other body chan
`nels. Such body channels may include arteries, the
`esophagus, bile ducts, urethra, trachea and the like.
`Other speci?c uses to which the procedures described
`in the present invention include the repair or correction
`of the following: intraluminal lining of AAA or iliac or
`femoral aneurysms; recanalization of injured vessels
`caused by blunt or penetrating trauma; dilation and
`recanalization of stenotic arterial segments; tampanade
`and obliteration of bleeding esophageal varices; recana
`lization of esophageal stenoses secondary to carcinoma
`or benign strictures; dilation and recanalization of co
`arctation of aorta; dilation and recanalization of biliary
`stenoses secondary to strictures, tumors and cancer of
`pancreas and common bile duct; ureteral strictures and
`tracheal strictures.
`It should also be understood that the above use list is
`not intended to be exclusive and that any body vessel
`which has been narrowed, weakened, or in another way
`requires a reinforcement may be subject to the present
`invention. Also as utilized therein, the term vessel is
`used in a generic sense to include body channels includ
`ing but not limited to artery, esophagus, bile duct, ure
`tha, trachea, and the like and that the term body in
`cludes not only humans but animals as well.
`One form of the present invention is illustrated in
`FIGS. 1 through 4 wherein an aortic aneurysm is shown
`being repaired by the procedure shown by the progres
`sive drawing sequence of FIGS. 1 through 3. Therein
`an aneurysm 10 is depicted intermediate patent proxi
`mal or ?rst and distal or second portions 12, 14 of the
`aorta 16. The lining of the aneurysm 10 includes clotted
`blood material or plaque 18 which in turn reduces the
`effective passage of arterial blood through the aorta and
`
`Edwards Exhibit 1031, p. 3
`
`

`

`O
`
`20
`
`4,512,338
`3
`increases the chance of clotted material entering the
`blood stream and causing damage elsewhere in the
`body.
`A hollow sheath 20 is shown inserted as by conven
`tional techniques into the aorta 16 from the distal side
`thereof as pictured to the right of FIG. 1 and positioned
`so as to be adjacent the proximal side of the aneurysm
`10 but well within the patent portion 12 thereof (distal
`and proximal refer to positioning relative to the heart,
`that is, remote from and close to respectively). In this
`regard, an arrow pointing towards the position of the
`patient’s heart has been placed at the proximal side in
`each drawing ?gure. A fabric graft 22 is positioned
`within the sheath 20 and is selected of an adequate lon
`gitudinal extent so as to adequately span the aneurysm
`10, that is, to contact patent vessel portions 12 and 14 on
`opposite sides of such aneurysm. The sheath 20 may
`include an enlarged proximal end 50 to accomodate the
`folded or bunched together, etc. graft structure 22.
`Such graft 22 may take the form of those currently
`utilized in full surgical techniques such as previously
`referred to in the Zollinger et al publication and utilized
`to at least in part illustrate the state of the prior art prior
`to the present invention. Such Dacron or other syn
`thetic or natural material graft may be accordian
`25
`pleated such that its overall length is shortened when
`introduced, then expanded as will hereinafter be more
`fully explained so as to span the full extent of the aneu
`rysm.
`A shape memory metal alloy wire is attached to the
`graft 22 at least at its proximal end and may be attached
`at a plurality of longitudinally spaced locations along
`such graft. The wire 24 is of an alloy such as Nitinol
`which exhibits anthropomorphic qualities of memory
`and trainability and are commonly referred to as shape
`memory alloys. If such alloys are plastically deformed
`at one temperature, they will completely recover to
`their original shape on being raised to a higher tempera
`ture. A discussion and identi?cation of such alloys is set
`forth in the article by L. McDonald Shetky entitled
`40
`“Shape-Memory Alloys” at Pages 74 through 82 of
`Vol. 241 (5) Nov. 1979 Scientific American a copy of
`which is attached hereto and speci?cally incorporated
`into this speci?cation by speci?c reference thereto. A
`further discussion of such alloys and particularly nickel
`45
`titanium alloys commonly referred to as nitonol is set
`forth in the publication “A Source Manual for Informa
`tion on Nitonol and NiTi”, First Revision, by David
`Goldstein, Research and Technology Department, Feb.
`1 1980, Naval Surface Weapons Center, Dahlgren, Va.
`22448 (NSWC TR 80-59), a copy of which is attached
`hereto and speci?cally incorporated into this speci?ca
`tion by speci?c reference thereto.
`In the present invention, a Nitinol wire 24 which has
`been alloyed to exhibit a martensite transformation tem
`perature somewhat below the normal body temperature
`range is satisfactory. Such wire is shaped by known
`techniques into the form of a continuous coil. The indi
`vidual loops 28 are disposed in adjacent but spaced
`relationship to each other while in a parent phase and
`thereafter cooled so as to produce a martensite crysta
`line form and thereafter reshaped so as to form a rela
`tively straight length of continuous wire. The wire 24 is
`maintained in such condition by maintaining the tem
`perature thereof below its martensite transformation
`temperature of approximately 37° in this case. The man
`ner in which said wire is attached to the graft 22 may be
`by conventional techniques such as sewing and the like.
`
`4
`In this regard, it should be pomted out that when the
`wire resumes its coiled form after being internally posi
`tioned in the body vessel, in this case the aorta 16. it will
`if appropriately attached to the graft 22 expand such
`graft longitudinally. Accordingly, a leading port1on of
`the wire 24 is attached to the graft and thereafter if
`desired at points along the length of the wire such that
`several continuous loops may be formed therebetween
`such attachment points. The wire intermediate such
`attachment points may be compressed or bunched so as
`to be conveniently housed within the proximal portion
`50 of the insulating sheath 20.
`Such sheath 20 is preferably formed of an insulating
`plastic resinous material such as polyethylene and the
`like and is of sufficient thickness so as to maintain the
`temperature of the wire 24 below its martensite trans
`formation point during the insertion of the sheath into
`the desired position within the aorta. Such position 15
`upstream of the aneurysm 10 (proximal to the heart) and
`generally adjacent thereto but well within the extent of
`the ?rst patent portion 12 of the aorta 16. Thereafter.
`the sheath 20 is initially withdrawn a short distance so
`as to expose a portion of the lead portion of the wire and
`graft 22 such that the wire is exposed to the heat of the
`surrounding body tissue and permitted to reach and
`exceed the martensite transformation phase and. ac
`cordingly, initiate reformation into its coiled form. In
`this regard, it should be pointed out that the diameter of
`the coil as initially formed is approximately equal to or
`slightly greater than that of the normal internal diame
`ter of the patent aorta portions 12 and 14 such that the
`individual loops 28 of the coil 26 urge the graft material
`22 snuggly against the patent portions of the aorta 16 so
`as to insure a positive position therein as shown In FIG.
`2. Thereafter the remainder of the insulation sheath is
`progressively removed such that the entire reformation
`of the coil takes place with the attendant longitudinal
`extension of the graft 22. The interior of the sheath may
`be ?tted with a relatively stiff member 52. Le, a wire or
`rod-like element, having a platform 54 attached at its
`proximal end and positioned within the enlarged sheath
`head 50. The member 52 may include a thumb ring 56 at
`its distal end such that the surgeon may more easily
`manipulate and thus position the sheath 20 as by insert
`ing his or her thumb through ring 56 and grasping the
`distal end of the sheath 20 by a flange 58 provided
`thereat.
`Also the diameter of the coil is preferably such that it
`approximates the normal internal extent of the aorta
`such that the passage of blood therethrough may be
`normal. Also where appropriate, the flow of blood
`through the aorta is temporarily shunted by conven
`tional means such as the insertion of an in?atable cathe
`ter if required or desirable in regard to the heating and
`shaping memory characteristics of the wire 24 or to
`assist in the initial positioning and/or expansion of the
`wire.
`It may thus be seen that the overall objectives otv the
`present invention are carried out by the move
`described novel procedure and such is accomplished
`without full surgical techniques and with a minimum
`possibility of dislodging clotted material from the aneu
`rysm 10 into the blood stream.
`Turning now to FIGS. 5 and 6 of the drawing, a
`modi?ed form of the invention is shown wherein the
`fabric graft 22 of the previously described embodiment
`has been omitted. In that regard, the formation of the
`coil 26a is such that the individual loops 28a thereof are
`
`65
`
`Edwards Exhibit 1031, p. 4
`
`

`

`25
`
`20
`
`4,512,338
`5
`6
`very closely spaced so as to approach or actually physi
`conjunction with the previously described embodi~
`cally touch each other. Otherwise, the procedure as
`ments. Also although the wire form has been illustrated
`previously described in the embodiment of FIGS. 1
`in the form of side by side circular loops along the
`through 4 is essentially the same, that is, an insulating
`longitudinal coil extent, it should be brought out that
`sheath v20 carrying the wire 24a is projected into the
`the loops could extend back and forth longitudinally
`vessel and thereafter the sheath slightly withdrawn
`and progressively build up in a circular path to form the
`such that the wire initially expands into a partial coil
`completed wire form (cylindrical).
`form and to directly contact the internal surface of the
`While there is shown and described herein certain
`?rst patent aorta portion 12 and thereafter progressively
`speci?c structure embodying this invention, it will be
`withdrawn so as to bridge the aneurysm 10 in the same
`manifest to those skilled in the art that various modi?ca
`manner as previously described and thereafter come
`tions and rearrangements of the parts may be made
`into positioning contact with the second patent portion
`without departing from the spirit and scope of the un
`14. The wire in this embodiment need not, however, be
`derlying inventive concept and that the same is not
`bunched so as to be positioned essentially entirely
`limited to the particular forms herein shown and de
`within the graft but may include only forward portions
`scribed except insofar as indicated the the scope of the
`appended claims.
`of such positioned in the sheath. Thus the wire 24a can
`be of the relatively straight form shown and have a
`What is claimed is:
`signi?cant extent project rearwardly out of the sheath
`1. The process of restoring the patency and/or re
`and patient’s body. In this embodiment, it is also possi
`establish continuity of a disrupted hollow body vessel a
`ble to use a sheath of reduced diameter approaching
`patient which includes a localized defect disposed inter
`even that of the wire. Furthermore, the wire may actu
`mediate proximal and distal patent vessel portions, com
`ally be moved relatively to a stationary sheath so as to
`prising inserting at least the forward end of a shape
`project outwardly of the lead end of the sheath so as to
`memory allow wire having a parent phase and a mar
`?rmly position the wire vis-a-vis the patent vessel por
`tensite phase and a temperature transformation point
`tion 12 or even to initiate heating and thus reformation
`therebetween and which wire has been previously
`of the wire in this manner.
`formed in its parent phase to form a longitudinally ori
`It should also be brought out that a procedure com
`ented coil of adjacent wire loops and then cooled to its
`bining the techniques and constructions shown and
`martensite phase and reshaped to an alternate form
`described in the FIGS. 1-4 and FIGS. 5 and 6 embodi
`before insertion along the interior of said vessel past said
`ments may be used as when a graft to which the wire is
`defect to a position adjacent the proximal patent vessel
`attached only to its leading or proximal end is used.
`portion while maintaining the temperature of said wire
`Therein the member 52 may be utilized and constructed
`below its martensite transformation point and thereafter
`to be hollow (tubular) such that the wire 24 or 240 can
`permitting the forward portion of said wire to be
`pass internally through it outwardly into the enlarged
`warmed above its transformation point so as to initially
`sheath head 50 through an opening (not shown) pro
`cause said alternate form to substantially revert to said
`vided in the platform 54. Also this combined technique.
`parent phase coil form and to cause the thus reformed
`could also be of use when a bunched wire 24 or 240 is
`wire loops of the forward wire end to be urged against
`placed in the sheath head 50 yet further wire is desired
`the interior of said proximal patent vessel portion so as
`to follow and as an aid in initially moving the wire
`to be at least temporarily positioned thereat and thereaf
`bunch relative to the sheath to initiate position.
`ter permit the reformation of the remainder of said coil
`Turning now to FIGS. 7 and 8 of the drawing, the
`so as to bridge said localized defect and extend into said
`present process is shown in directing a constricted ves
`distal patent vessel portion, said warming being pro
`sel 30 such that the constriction is forced to more natu
`gressive in the proximal to distal direction.
`ral or at least patent dimensions by the application of the
`2. The process of claim 1, said reformed wire loops
`being substantially circular.
`techniques of the present invention. In such case, a wire
`45
`34 which may correspond to either the wire 24 or 24a of
`3. The process of claim 1 wherein the martensite
`the previously explained embodiments may be utilized.
`transformation temperature of said wire is below the
`Such wire 34 is positioned on one side of the constric
`normal temperature range of said body.
`tion 32 by a sheath 36 which may be of smaller diameter
`4. The process of claim 3 wherein said wire in com
`than sheath 20 and thereafter heated to its martensite
`posed of a Nitinol alloy.
`transformation point and then enabled to progressively
`5. The process of claim 1 wherein said warming of
`said wire takes place by said body.
`reshape itself to its original coil form 38 so as to progres
`sively force the walls of the vessel into an original or at
`6. The process of claim 1 wherein the temperature of
`least patent position. A length of graft material can also
`said wire is regulated by insulating means when initially
`be used in conjunction with the process as shown in
`inserted into said vessel.
`FIGS. 7 and 8.
`7. The process of claim 6 wherein said insulating
`It should be brought out that heating the wire in any
`means is a tube through which said wire is transported
`of the above embodiments to its transformation temper
`to said proximal patent portion after which said tube is
`progressively withdrawn.
`ature could be accomplished other than solely by con
`duction and convection from the body but by infrared
`8. The process of claim 7 wherein a tubular graft is
`radiation. Thus infrared waves could be directed at
`positioned over said wire in its alternate form prior to
`forward portions of the wire by known means so as to
`inserting said wire and said graft into said vessel.
`progressively heat and reform the wire. Also when the
`9. The process of claim 8 wherein said wire is at
`body temperature is not exclusively relied upon as the
`tached to said graft at least at the forward or proximal
`source of heat for the wire, its reformation temperature
`end thereof and said wire and graft are positioned in
`could be increased above body temperatures if neces
`said tube in a crushed compacted form.
`sary or desirable to achieve particular characteristics.
`10. The process of claim 1 'wherein the adjacent loops
`Naturally, radiation heating could also be utilized in
`of said reformed coil are closely spaced to each other so
`
`55
`
`65
`
`Edwards Exhibit 1031, p. 5
`
`

`

`7
`as to essentially form the wall of the vessel in said defec
`tive portion thereof.
`11. The process of claim 1 wherein a tubular graft is
`positioned over said wire in its alternate form prior to
`inserting said wire and said graft into said vessel.
`12. The process of claim 1 wherein said wire is con
`tinuous.
`13. The process of claim 1 wherein said alternate wire
`form is a substantially straight length thereof.
`14. The process of claim 1, said alternate form of said
`wire being a crushed compacted form adapted for inser
`tion into said body vessel.
`15. The process of restoring the patency and/or re
`establish continuity of a disrupted hollow body vessel of
`a patient which includes a localized defect disposed
`intermediate proximal and distal patent vessel portions,
`comprising inserting at least the forward end of a shape
`memory alloy wire having a parent phase and a mar
`tensite phase and a temperature transformation point
`therebetween which is somewhat below the body tem
`perature of said patent and which wire which has been
`
`8
`previously formed in its parent phase to form a longitu
`dinally oriented coil of adjacent wire loops and then
`cooled to its martensite phase and reshaped to an alter
`nate form before insertion along the interior of said
`vessel past said defect to a position adjacent the DI‘OXI
`mal patent vessel portion while maintaining the temper
`ature of said wire below its martensite transformation
`point and thereafter permitting said wire to be progres
`sively warmed in the proximal to distal direction by the
`patient’s body above its transformation point so as to
`initially cause said alternate form to substantially revert
`to said parent phase coil form and to cause the thus
`reformed wire loops of the forward wire end to be
`urged against the interior of said proximal patent vessel
`portion so as to be a least temporarily positioned thereat
`and thereafter permit the reformation of the remainder
`of said coil so as to bridge said localized defect and
`extend into position adjacent said distal patent vessel
`portion.
`
`8
`
`8
`
`z
`
`x
`
`t
`
`4,512,338
`
`15
`
`25
`
`35
`
`45
`
`55
`
`65
`
`Edwards Exhibit 1031, p. 6
`
`