Page 1 of 6
`
`Edwards Lifesciences v. Boston Scientific
`U.S. Patent No. 6,915,560
`IPR2017-00444 EX. 2021
`
`

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`US. Patent
`
`Sep. 22, 1998
`
`5,810,838
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`5,810,838
`
`1
`HYDRAULIC METHOD AND APPARATUS
`FOR UNIFORM RADIAL COMPRESSION
`AND CATHETER MOUNTING OF RADIALLY
`EXPANDABLE INTRALUMINAL STENTS
`AND STENTED GRAFTS
`
`FIELD OF THE INVENTION
`
`invention pertains generally to medical
`The present
`devices, and more particularly to an apparatus and method
`for mounting a stent or stented graft onto a delivery catheter
`through the use of hydraulics to facilitate the uniform radial
`compression of the stent or stented graft.
`BACKGROUND OF THE INVENTION
`
`The term “stent” is generally used to describe endoproth-
`stetic medical devices which are implanted in anatomical
`passageways (e. g., blood vessels, gastrointestinal tract, geni-
`tourinary tract, endocrine ducts, etc .
`.
`. ) of the body for the
`purpose of maintaining the patency or state of dilation of the
`passageway, reinforcing the passageway, or anchoring a
`tubular graft or other object within the passageway.
`Typically, such stents are implanted in blood vessels to
`maintain dilation and patency of an occluded region of blood
`vessel, or to bridge a weakened or aneurysmic region of
`blood vessel. On the other hand, some typical non-vascular
`applications of such stents are for the treatment of constric-
`tions or
`injuries to the gastrointestinal
`tract
`(e.g.,
`esophagus), ducts of the biliary tree (e.g., common bile duct)
`or anatomical passageways of the genitourinary tract (e.g.,
`ureter, urethra fallopian tube, etc.).
`Transluminally implantable stents are initially disposed in
`a compact configuration of relatively small diameter, and are
`initially mounted upon or within a delivery catheter to
`facilitate insertion and transluminal advancement of the
`
`stent into the desired anatomical passageway. Thereafter,
`such stents are radially expanded to a larger “operative”
`diameter which is equal
`to or slightly larger than the
`diameter of the anatomical passageway in which the stent is
`to be implanted. When radially expanded to such operative
`diameter, the stent will typically become released or sepa-
`rated from the delivery catheter and anchored or frictionally
`engaged to the surrounding wall of the anatomical passage-
`way.
`
`Some stents have a pliable, continuous tubular covering,
`in which case they are typically referred to as a “stented
`graft” or “stent-graft”.
`In general, stents and stented grafts fall into two major
`categories—a) self-expanding and b) pressure-expandable.
`Those of the self-expanding variety may be formed of
`resilient or shape memory material (e.g., spring steel or
`nitinolTM) which is capable of self-expanding from its first
`(radially compact) diameter to its second (operative) diam-
`eter without the exertion of outwardly-directed force against
`the stent or stented graft. Examples of such self-expanding
`stents and stented grafts are set forth in US. Pat. Nos.
`4,655,771 (Wallsten, et al); 4,954,126 (Wallsten); 5,061,275
`(Wallsten, et al); 4,580,568 (Gianturco); 4,830,003 (Wolf, et
`al); 5,035,706 (Gianturco, et al); 5,330,400 (Song) and
`5,354,308 (Simon, et al) and Foreign Patent Publication
`Nos. W094\12136; W092\06734 and EPA183372. Those of
`the pressure-expandable (i.e., “passive expandable”) variety
`may be formed of plastically deformable material (e.g.,
`stainless steel) which is initially formed in its first (radially
`compact) diameter and remains stable in such first diameter
`until such time outwardly directed pressure is exerted upon
`the stent or stented graft to cause radial expansion and
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`resultant plastic deformation of the stent or stented graft, to
`its second (operative) diameter. Examples of such pressure-
`expandable stents and stented grafts are set forth in US. Pat.
`Nos.5,135,536 (Hillstead); 5,161,547 (Tower); 5,292,331
`(Boneau); 5,304,200 (Spaulding); 4,733,665 (Palmaz);
`5,282,823 (Schwartz, et al); 4,776,337 (Palmaz); and 5,403,
`341 (Solar) and Foreign Patent Publication Nos.
`EPA480667; and W09508966.
`In many applications, careful positioning and sound
`anchoring of the stent or stented graft
`is critical to the
`successful treatment of the underlying medical problem. In
`this regard, the delivery catheter which is utilized to insert
`and position the stent or stented graft may be an important
`aspect of the overall system. Various types of delivery
`catheters for stents and stented grafts have been previously
`known, including those described in US. Pat. Nos. 4,665,
`918 (Garza, et al); 4,733,665 (Palmaz); 4,739,762 (Palmaz);
`4,762,125 (Leiman, et al);,776,337 (Palmaz); 4,838,269
`(Robinson, et al); 4,994,071 (MacGregor); 5,037,427
`(Harada, et al); 5,089,005 (Harada); 5,102,417 (Palmaz);
`5,108,416 (Ryan, et al); 5,141,498 (Christian); 5,181,920
`(Mueller, et al); 5,195,984 (Schatz); 5,201,901 (Harada, et
`al); 5,269,763 (Boehmer, et al); 5,275,622 (Lazarus, et al);
`5,290,295 (Querals, et al); 5,306,294 (Winston, et al); 5,318,
`588 (Horzewski, et al); 5,344,426 (Lau, et al); 5,350,363
`(Goode, et al); 5,360,401 (Turnland); 5,391,172 (Williams,
`et al); 5,397,345 (Lazarus); 5,405,380 (Gianotti, et al);
`5,443,452 (Hart, et al); 5,453,090 (Martinez, et al); 5,456,
`284 (Ryan, et al); and 5,456,694 (Marin, et al) and Foreign
`Patent Publication Nos. EP-0308-815-A2; EP-0335-341-
`A1; EP-364-787-A; EP0442-657-A2; EP-482976-A;
`EP-0505-686-A1; EP-0611-556-A1; EP-0638-290-A1;
`W094\15549; W095\01761; GB2196-857-A; DE3042-229;
`and DE3737-121-A.
`
`As previously indicated, many types of stents or stented
`grafts are currently used in relation to the treatment of
`various disorders. Perhaps the most common use of radially
`expandable stents and stented grafts is in relation to the
`treatment of narrowed or constricted blood vessels. For
`
`these applications, pressure expandable stents are typically
`employed, with the delivery of the stent
`to the desired
`treatment site being facilitated through the use of a delivery
`catheter including an inflatable balloon which is used to
`facilitate the radial expansion of the stent positioned there-
`upon to its final, operative diameter.
`When using pressure expandable stents or stented grafts
`on a delivery catheter including an inflatable balloon, the
`stent or stented graft must be manually mounted to the
`balloon of the delivery catheter by the physician prior to the
`initiation of the treatment. Such mounting is typically
`accomplished by the physician manually squeezing or com-
`pressing the stent or stented graft onto the balloon of the
`delivery catheter. It is also known in the prior art for delivery
`catheters to be provided wherein the stent or stented graft is
`premounted thereto. In this respect, the stent or stented graft
`is mounted to the delivery catheter by the manufacturer, and
`sold as a combined unit.
`
`Though the above-described mounting procedure is often
`used, a major drawback associated therewith is that often
`times the stent or stented graft is not uniformly compressed
`onto the balloon of the delivery catheter. Indeed, the hand
`crimping of the stent or stented graft onto the balloon of the
`delivery catheter usually results in uneven crimping. Such
`non-uniform or uneven crimping of the stent or stented graft
`onto the balloon in turn results in non-uniform or uneven
`
`re-expansion of the stent or stented graft when radially
`expanded by the inflation of the balloon. If re-expanded in
`
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`5,810,838
`
`3
`the stent or stented graft, though
`a nonuniform manner,
`being in contact with the luminal surface of a particular
`anatomical passageway, will not necessarily exert even
`pressure thereagainst, which is undesirable due to the
`increased risk of the stent or stented graft dislodging from its
`operative position within the treatment site. Additionally,
`such non-uniform crimping may cause problems during the
`advancement of the delivery catheter through the anatomical
`passageway to the desired treatment site. Such problems
`include those portions of the stent or stented graft which are
`not compressed against the balloon of the delivery catheter
`inadvertently contacting and damaging the lining of the
`luminal surface of the anatomical passageway.
`In view of the foregoing, it is highly desirable to facilitate
`the uniform crimping or compression of the stent or stented
`graft over the balloon of the delivery catheter. The present
`invention addresses this need by providing an apparatus and
`method which, through the use of hydraulics, facilitates the
`uniform radial compression of the stent or stented graft
`about a portion of the delivery catheter. The present inven-
`tion is used primarily in relation to pressure expandable
`stents or stented grafts which are mounted to the balloon of
`a delivery catheter. However, the present invention may also
`be used in relation to self-expanding stents or stented grafts
`including a latching mechanism which engages when the
`stent or stented graft is radially compressed.
`
`SUMMARY OF THE INVENTION
`
`In accordance with the present invention, there is pro-
`vided an apparatus for mounting a radially expandable
`intraluminal stent or stented graft onto a delivery catheter.
`The apparatus comprises a hollow housing which defines an
`interior chamber and a fluid port which communicates with
`the interior chamber. Disposed within the interior chamber
`of the housing is a collapsible, resilient tubular sleeve which
`is sized to receive a portion of the delivery catheter having
`the stent or stented graft positioned thereupon. The sleeve
`includes an open end which communicates with the exterior
`of the housing. In the present apparatus, the pressurization of
`the interior chamber of the housing via its fluid port facili-
`tates the uniform radial compression of the elongate sleeve,
`with the depressurization of the housing via its fluid port
`being operational to allow the sleeve to resiliently return to
`an uncompressed state. The collapse of the sleeve in turn
`facilitates the uniform radial compression or crimping of the
`stent or stented graft therewithin, thus mounting the stent or
`stented graft onto the delivery catheter. Typically, the present
`apparatus is used in conjunction with pressure expandable
`stents for mounting the same onto the radially expandable
`balloon of a delivery catheter.
`The elongate, tubular sleeve of the present apparatus may
`be fabricated from polyethylene (PE) having a preferred
`wall thickness of from about 0.001 to 0.003 inches. The
`
`sleeve may alternatively be fabricated from polyethylene
`terephthalate (PET) having a preferred wall thickness of
`from about 0.0001 to 0.001 inches, or
`from nylon
`(PEBAXTM, Atochimie, Courbevoie, Hauts-Ve-Sine,
`France) having a preferred wall thickness of from about
`0.001 to 0.003 inches. Additionally,
`the sleeve may be
`fabricated from an elastomeric material having a preferred
`wall thickness of approximately 0.005 inches.
`In the apparatus constructed in accordance with the
`present
`invention,
`the housing may further comprise a
`pressure gauge fluidly connected to the interior chamber for
`monitoring the pressure level
`therewithin. The interior
`chamber of the housing is typically pressurized with a fluid,
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`and preferably a liquid for minimum compressibility.
`However, the interior chamber may alternatively be pres-
`surized with a gas, though the use of a gas for the pressur-
`izing medium is less desirable due to its increased com-
`pressibility as compared to a liquid. The pressurization of
`the interior chamber is typically facilitated by an angioplasty
`balloon inflation device (e.g., the syringe used to inflate the
`balloon of the delivery catheter). In some instances, the
`angioplasty balloon inflation device may include its own
`pressure gauge, thus eliminating the need for the optional
`pressure gauge fluidly connected to the interior chamber of
`the housing. However, those of ordinary skill in the art will
`recognize that alternative devices may be used to pressurize
`the interior chamber of the housing.
`Further in accordance with the present invention, there is
`provided a hydraulic method of mounting a radially expand-
`able intraluminal stent or stented graft onto a delivery
`catheter. The method comprises the initial step of providing
`a crimping apparatus which has the above-described struc-
`tural and functional attributes. Thereafter, a radially expand-
`able stent or stented graft is positioned upon a portion of the
`delivery catheter, with that portion of the delivery catheter
`having the stent or stented graft positioned thereupon then
`being inserted into the sleeve via the open end thereof.
`Thereafter, the interior chamber of the housing is pressur-
`ized via the fluid port to facilitate the uniform radial com-
`pression of the sleeve and the stent or stented graft posi-
`tioned therein about
`the delivery catheter. The interior
`chamber of the housing is then depressurized via the fluid
`port, with the portion of the delivery catheter having the
`stent or stented graft mounted thereto being removed or
`withdrawn from within the interior of the sleeve.
`
`the interior chamber of the
`As previously indicated,
`housing is typically pressurized with a fluid through the use
`of the syringe or other inflation fluid infusion device used to
`facilitate the inflation of the balloon of the delivery catheter.
`Additionally, the stent positioned upon the delivery catheter
`will typically comprise a pressure expandable stent, though
`self-expanding stents including latching mechanisms which
`engage when the stent is collapsed may also be used in
`conjunction with the present invention.
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`These, as well as other features of the present invention,
`will become more apparent upon reference to the drawings
`wherein:
`
`FIG. 1 is a perspective view of the mounting apparatus of
`the present invention, illustrating the manner in which a
`delivery catheter having an uncompressed stent positioned
`thereupon is inserted into the mounting apparatus;
`FIG. 2 is a cross-sectional view of the mounting
`apparatus,
`illustrating the delivery catheter and uncom-
`pressed stent as positioned therein prior to the pressurization
`of the interior chamber thereof;
`FIG. 3 is a cross-sectional view of the mounting
`apparatus,
`illustrating the delivery catheter and radially
`compressed stent as positioned therein subsequent to the
`pressurization of the interior chamber thereof;
`FIG. 4 is a cross-sectional view taken along line 4—4 of
`FIG. 3; and
`FIG. 5 is a partial perspective view of the delivery
`catheter, illustrating the stent as being radially compressed
`thereon through the use of the mounting apparatus shown in
`FIGS. 1—3.
`
`DETAILED DESCRIPTION OF THE
`PREFERRED EMBODIMENT
`
`Referring now to the drawings wherein the showings are
`for purposes of illustrating a preferred embodiment of the
`
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`5,810,838
`
`5
`present invention only, and not for purposes of limiting the
`same, FIG. 1 perspectively illustrates an apparatus 10 for
`mounting a radially expandable intraluminal stent 12 or
`stented graft onto a delivery catheter 14. The stent 12 with
`which the apparatus 10 is utilized will typically comprise a
`pressure expandable stent, with the stent 12 shown in FIGS.
`1—5 being of a type commonly referred to as a “zig-zag”
`stent. Additionally, the delivery catheter 14 upon which the
`pressure expandable stent 12 is positioned will typically
`comprise a balloon delivery catheter having a tubular body
`16 which includes an elongate,
`inflatable balloon 18
`attached to the outer surface thereof in relative close prox-
`imity to its distal end. The stent 12 is mounted to the balloon
`18 of the delivery catheter 14 by initially positioning the
`stent 12 over the balloon 18, and subsequently radially
`compressing the stent 12 thereabout. The deployment of the
`collapsed stent 12 into a desired intraluminal site is facili-
`tated by the inflation of the balloon 18, which in turn causes
`the stent 12 mounted thereto to be expanded radially out-
`wardly into direct contact with the luminal surface of an
`anatomical passageway. As will be described in more detail
`below, the apparatus 10 of the present invention is specifi-
`cally adapted to facilitate the mounting of the stent 12 onto
`the delivery catheter 14 through the uniform radial com-
`pression of the stent 12 about the balloon 18.
`Those of ordinary skill in the art will recognize that the
`apparatus 10 of the present invention may also be used to
`facilitate the mounting of other types of pressure expandable
`stents or stented grafts onto the balloon 18 of the delivery
`catheter 14. Additionally, the apparatus 10 may be used to
`facilitate the mounting of self-expanding stents or stented
`grafts onto the balloon 18 of the delivery catheter 14 wherein
`such self-expanding stents or stented grafts include latching
`mechanisms which engage when the stent or stented graft is
`collapsed. Moreover,
`the apparatus 10 may be used to
`facilitate the mounting of stents or stented grafts onto
`delivery catheters other than for balloon delivery catheters.
`Thus, the particular descriptions of the stent 12 and delivery
`catheter 14 set forth herein are for illustrative purposes only
`and are not
`intended to limit
`the scope of the present
`invention.
`
`In the preferred embodiment, the apparatus 10 comprises
`a hollow, cylindrically configured housing 20 which defines
`a proximal end 22 and a distal end 24. The distal end 24 of
`the housing 20 may be enclosed by an end cap 26 which,
`though not shown, may comprise an integral portion of the
`housing 20. Disposed within the proximal end 22 of the
`housing 20 is an annular entry member 28 which defines a
`circularly configured opening 30 extending axially there-
`through. The housing 20, end cap 26 and entry member 28,
`and more particularly the inner surfaces thereof, collectively
`define an interior chamber 32 of the housing 20.
`As best seen in FIGS. 2 and 3, disposed within the interior
`chamber 32 of the housing 20 is a collapsible, resilient
`tubular sleeve 34 having a proximal end which is attached to
`the inner surface of the entry member 28 and a distal end
`which is attached to the inner surface of the end cap 26.
`When attached to the entry member 28, the proximal end of
`the sleeve 34 circumvents the opening 30, with the inner
`surface of the sleeve 34 being substantially continuous with
`the peripheral inner wall of the entry member 28 which
`defines the opening 30. When attached to the end cap 26 and
`entry member 28 in the aforementioned manner, the sleeve
`34 extends axially through the interior chamber 32, with the
`interior of the sleeve 34 communicating with the exterior of
`the apparatus 10 via the opening 30 within the entry member
`28.
`
`6
`The sleeve 34 of the apparatus 10 may be fabricated from
`polyethylene (PE) having a preferred wall thickness of from
`about 0.001 to 0.003 inches. The sleeve 34 may alternatively
`be fabricated from polyethylene terephthlate (PET) having a
`preferred wall
`thickness of from about 0.0001 to 0.001
`inches, or from nylon (PEBAXTM, Atochimie, Courbevoie,
`Hauts-Ve-Sine France) having a preferred wall thickness of
`from about 0.001 to 0.003 inches. Additionally, the sleeve 34
`may be fabricated from an elastomeric material having a
`preferred wall thickness of approximately 0.005 inches. In
`all embodiments, the sleeve 34 is sufficiently resilient to be
`selectively collapsible and expandable in accordance with
`changes in the pressure level within the interior chamber 32,
`as will be discussed in more detail below.
`
`As seen in FIGS. 1—3, the apparatus 10 constructed in
`accordance with the present invention further comprises a
`fluid port 36 which is attached to the housing 20 and
`communicates with the interior chamber 32 thereof. Also
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`attached to the housing 20 adjacent the fluid port 36 is a
`pressure gauge 38 which also communicates with the inte-
`rior chamber 32.
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`Having thus described the structural components of the
`apparatus 10, the method of using the same to facilitate the
`mounting of the stent 12 upon the balloon 18 of the delivery
`catheter 14 will now be described with reference to FIGS.
`1—5.
`
`In the present method, the stent 12, while in its uncol-
`lapsed state, is centrally positioned upon the balloon 18 of
`the delivery catheter 14 such that the opposed ends of the
`balloon 18 protrude from respective ends of the stent 12.
`Thereafter, as seen in FIG. 2, the delivery catheter 14 having
`the stent 12 positioned upon the balloon 18 is inserted into
`the interior of sleeve 34 via the opening 30 within the entry
`member 28. Importantly, the inner diameter of the sleeve 34
`is sized so as to allow the uncollapsed stent 12 to be easily
`inserted into the sleeve 34 without interfering with the inner
`surface thereof.
`
`Subsequent to the insertion of the delivery catheter 14 and
`stent 12 into the sleeve 34 in the manner shown in FIG. 2,
`the interior chamber 32 of the housing 20 is pressurized via
`the fluid port 36. More particularly, the interior chamber 32
`is pressurized with a fluid, with such pressurization typically
`being facilitated by an angioplasty balloon inflation device
`(e.g.,
`the syringe used to inflate the balloon 18 of the
`delivery catheter 14). However, those of ordinary skill in the
`art will recognize that alternative devices may be used to
`pressurize the interior chamber 32 of the housing 20. As seen
`in FIG. 3, due to the resiliency of the sleeve 34,
`the
`pressurization of the interior chamber 32 in the aforemen-
`tioned manner facilitates the uniform radial compression of
`the sleeve 34 about the stent 12 positioned therewithin. The
`application of the uniform radial compressive forces to the
`stent 12 by the sleeve 34 in turn causes the stent 12 to be
`uniformly radially collapsed or compressed about
`(i.e.,
`mounted to) the balloon 18 of the delivery catheter 14.
`After the stent 12 has been mounted to the balloon 18 of
`
`the delivery catheter 14 in the aforementioned manner, the
`interior chamber 32 of the housing 20 is depressurized via
`the fluid port 36. The resultant return of the interior chamber
`32 to atmospheric pressure causes the sleeve 34 to resiliently
`return to its original, uncompressed configuration as shown
`in FIG. 2. Thereafter, the delivery catheter 14 having the
`stent 12 mounted thereto is removed from within the sleeve
`
`34 via the opening 30, with the stent 12 being tightly
`collapsed onto the balloon 18 of the delivery catheter 14 in
`the manner shown in FIG. 5.
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`5,810,838
`
`7
`The optional inclusion of the pressure gauge 38 with the
`apparatus 10 provides a visual indication as to whether the
`pressure level within the interior chamber 32 is sufficient to
`facilitate the uniform radial compression of the sleeve 34
`from its uncollapsed state (shown in FIG. 2) to its collapsed
`state (shown in FIG. 3).
`It will be recognized that an
`additional or alternative visual indication of the sleeve 34
`
`moving to its collapsed state may be achieved by fabricating
`the housing 12 from a transparent or translucent material.
`
`Advantageously, the apparatus 10 constructed in accor-
`dance with the present
`invention facilitates the uniform
`crimping or compression of the stent 12 or stented graft over
`the balloon 18 of the delivery catheter 14. Due to such
`uniform compression,
`the stent 12 radially expands in a
`uniform manner upon the inflation of the balloon 18 and thus
`exerts even pressure against
`the luminal surface of the
`anatomical passageway when placed into direct contact
`wherewith. As such,
`the stent 12, when in its operative
`position within the anatomical passageway, is less suscep-
`tible to dislodging within the treatment site. Additionally, the
`uniform compression of the stent 12 about the balloon 18
`substantially decreases the risk of the stent 12 inadvertently
`contacting and damaging the lining of the luminal surface of
`the anatomical passageway during the advancement of the
`delivery catheter 14 to the desired treatment site.
`
`Additional modifications and improvements of the
`present invention may also be apparent to those of ordinary
`skill in the art. Thus, the particular combination of parts
`described and illustrated herein is intended to represent only
`one embodiment of the present
`invention, and is not
`intended to serve as limitations of alternative devices within
`
`the spirit and scope of the invention.
`What is claimed is:
`
`1. A method of mounting a radially expandable intralu-
`minal stent onto a delivery catheter, said method comprising
`the steps of:
`
`(a) providing a stent mounting apparatus which com-
`prises:
`(1) a hollow housing defining an interior chamber
`which is filled with a fluid; and
`(2) a collapsible,
`resilient
`tubular sleeve disposed
`within the interior chamber of the housing, said
`sleeve having an open end which communicates with
`the exterior of the housing;
`(b) positioning the radially expandable stent upon a
`portion of the delivery catheter;
`(c) inserting the portion of the delivery catheter having the
`stent positioned thereupon into the sleeve; and
`(d) pressurizing the fluid within the interior chamber of
`the housing to facilitate the uniform radial compression
`of the sleeve and the stent positioned therein about the
`delivery catheter.
`
`8
`2. The method of claim 1 further comprising the steps of:
`(e) depressurizing the interior chamber of the housing;
`and
`
`(f) removing the portion of the delivery catheter having
`the stent mounted thereto from within the sleeve.
`
`3. The method of claim 1 wherein step (b) comprises
`positioning a pressure expandable stent onto the delivery
`catheter.
`
`4. The method of claim 1 wherein step (d) comprises
`pressurizing the interior chamber of the housing with a
`liquid.
`5. The method of claim 1 wherein step (d) comprises
`pressurizing the interior chamber of the housing with a gas.
`6. A system for installing a radially expandable intralu-
`minal prosthesis within a body lumen wherein the system
`comprises an elongate, pliable delivery catheter having a
`radial expansion member formed thereon, and a radially
`expandable prosthesis mounted upon said radial expansion
`member in a radially compact configuration such that sub-
`sequent expansion of the expansion member will cause the
`prosthesis to become radially expanded, wherein said pros-
`thesis has been mounted upon said delivery catheter by the
`method which comprises the steps of:
`(a) providing a stent mounting apparatus which com-
`prises:
`(1) a hollow housing defining an interior chamber
`which is filled with a fluid;
`(2) a collapsible,
`resilient
`tubular sleeve disposed
`within the interior chamber of the housing, said
`sleeve having an open end which communicates with
`the exterior of the housing;
`(b) positioning the radially expandable stent upon a
`portion of the delivery catheter;
`(c) inserting the portion of the delivery catheter having the
`stent positioned thereupon into the sleeve; and
`(d) pressurizing the fluid within the interior chamber of
`the housing to facilitate the uniform radial compression
`of the sleeve and the stent positioned therein about the
`delivery catheter.
`7. The method of claim 6 wherein the radially expandable
`prosthesis is a stent.
`8. The method of claim 7 wherein the radially expandable
`prosthesis is a stent formed of plastically deformable mate-
`rial.
`
`9. The method of claim 7 wherein the radially expandable
`prosthesis is a stent having a ratchet mechanism which
`enables the stent to be radially expanded by exertion of
`outward radial pressure against the stent.
`10. The method of claim 6 wherein the radially expand-
`able prosthesis is a stented graft.
`11. The method of claim 10 wherein the stented graft is a
`tubular graft having at least one radially expandable stent
`member attached thereto.
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
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`Page 6 of 6
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`Page 6 of 6
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