Edwards Lifesciences Corporation, et al. Exhibit 1137, Page 1 of 12
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`

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`VOLUME 2
`
`Second Edition
`
`TEXTBOOK
`
`fO
`
`INTERVENTIONAL
`
`CARDIOLOGY
`
`ERIC 1. TOPOL, MD.
`
`Chairman, Department of Cardiology
`Director, Center for Thrombosis and Vascular Biology
`Cleveland Clinic Foundation
`Professor of Medicine
`Cleveland Clinic: Health Sciences Center
`Ohio State University
`Cleveland, Ohio
`
`'
`
`.
`;
`
`W.B. SAUNDERS COMPANY
`A Division of Harcourt Brace 8 Company
`
`Philadelphia, London, Toronto, Montreal, Sydney, Tokyo
`
` .{COW—C”‘V
`lHHHHl
`HHH ‘
`
`
`
`
`Edvvards Lifesciences Corporation, et al. Exhibit 1137, Pagglgwfiéasomwgm
`
`
`
`Edwards Lifesciences Corporation, et al. Exhibit 1137, Page 2 of 12
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`

`

`
`
`W. B. SAUNDERS COMPANY
`A Division of Harcourt Brace 67 Company
`The Curtis Center
`Independence Square West
`Philadelphia, PA 19106
`
`
`
`Library of Congress Cataloging-in-Publlcatlon Data
`
`93-15130
`
`Textbook of interventional cardiology/ [edited by] Eric J. Topol —
`2nd ed.
`p.
`cm.
`Includes bibliographical references and index.
`ISBN 0-7216-6749-X (V. 1).—ISBN 0-7216-6750-3 (V. 2).—
`lSBN 0-72166722-8 (Set)
`1. Angioplasty.
`2. Cardiovascular system—Diseases—Treatment.
`l. Topol, Eric J.
`[DNLM:
`1. Cardiovascular Diseases—surgery.
`168 T355 1994]
`RD598.5.T49
`1994
`617.4’12059—dc20
`DNLM/DLC
`
`2. Angioplasty. WG
`
`‘I
`
`1
`l
`I
`
`l Vl
`
`Textbook of INTERVENTIONAL CARDIOLOGY
`
`Volume 1 0-7216-6749-X
`Volume 2 0-7216—6750-3
`
`Set ISBN 0-7216-6722-8
`
`Copyright © 1994, 1990 by w. B. Saunders Company.
`
`All rights reserved. No part of this publication may be reproduced or transmitted in any form or by
`any means, electronic or mechanical, including photocopy, recording, or any information storage and
`retrieval system, without permission in writing from the publisher.
`Printed in the United States of America.
`
`Last digit is the print number:
`
`9
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`8
`
`7
`
`6
`
`5
`
`4
`
`3
`
`2
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`1
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`' Edwards Lifesciences Corporation, et al. Exhibit 1137, 'Paggalpfigasomsgso
`
`Edwards Lifesciences Corporation, et al. Exhibit 1137, Page 3 of 12
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`

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`
`
`75
`Percutaneous Expandable
`Prosthetic Valves
`'
`
`' Steven R. Bailey
`
`V
`
`The introduction of percutaneous techniques for vascular
`intervention has resulted in the rapid development of new
`devices and techniques for the treatment of coronary and vas—
`cular diseases. One important area of potential interest is the
`application of percutaneous techniques for the treatment of
`valvular heart disease. The exponential growth of percuta—
`neous endovascular procedures is similar to that experienced
`in cardiovascular surgery after the introduction of cardiopul;
`monary bypass. The design of implantable prosthetic heart
`valves to be delivered using a percutaneous approach has
`become an important area for investigation.
`The initial implantation of a prosthetic heartvalve was per-
`formed in 1952 and published in 1953 by Hufnagel and Har-
`vey,1 with a follow-up report in 1954.2 The Hufnagel valve is
`composed of a chamber with a central ball valve as seen in
`~ Figure 75—]. This bulky device was surgically placed in the
`descending aorta distal to the left subclavian artery. Patients
`did surprisingly well clinically despite the fact that only 75
`per cent of the regurgitant volume was diminished using this
`valve in the descending aorta. Subcoronary placement of
`prosthetic valves became possible only after the introduction
`of cardiopulmonary bypass in 1960.3 The past three decades
`have seen significant improvements in the performance of
`mechanical, tissue, and homograft prosthetic valves, with nu-
`merous alterations occurring in the designs of these prosthe-
`ses.4 These changes have improved the functional orifice area
`as well as decreased the complications associated with valve
`replacement such as thrombus formation, embolism, and late
`valve dysfunction.
`Unfortunately, placement of prosthetic heart valves re-
`mains a relatively difficult and often dangerous procedure.
`The surgical risks rise rapidly in patients with serious prob-
`lems such as acute valvular regurgitation and in patients
`whose valvular disease is associated with myocardial
`ischernia?’6
`
`The development of percutaneous catheter—based systems
`for stabilization and treatment of unstable patients with val-
`vular disease, which could be performed at a lower risk to
`the patient, is therefore an important area for research. De-
`veloping a chronically implanted catheter—based valve pros-
`thesis is an exciting new frontier in interventional cardiology.
`1268
`
`HISTORY OF CATHETER-BASED VALVES
`
`The demonstrated success of the Hufnagel valve in treating
`aortic insufficiency precipitated the initial investigation in
`1965 by Hywel Davies7 of a catheter-mounted valve for tem-
`porary relief of aortic insufficiency. This device, although
`crude by today’s standards, was very interesting in design.
`As seen in Figure 75—2 this cone-shaped device was essen—
`tially an inverted parachute. The valve closed during systole
`due to the forward flow of blood out of the ventricle, and
`opened during diastole as the regurgitant flow returned to
`the ventricle. It was anchored onto a 5-H. catheter with thin
`guy wires. No information was provided regarding the type
`of material from which this valve was constructed. Initial an-
`imal experiments were promising, although no human inves-
`tigations were ever reported. One significant problem dis—
`played by this valve was the rapid development of thrombi
`at the base of the cone, a theme common to all prosthetic
`valves. This predisposition was probably enhanced by pro-
`longed stasis of blood in the base of the conical valve.
`Moulopoulos et al.3 reported their investigations into
`catheter-mounted aortic valves in 1971. Utilizing the investi-
`gators’ experience in developing electrocardiographically
`(ECG) triggered intra-aortic balloon pumps, they designed
`and evaluated three separate systems (Fig. 75—3). One was a
`spherical balloon triggered by the ECG to inflate during di-
`astole. The second was a spherical balloon that was pressure
`responsive and deflated when systolic pressure exceeded a
`predetermined value. It inflated when pressure fell below a
`specified diastolic value, resulting in diastasis. Their third
`system was an umbrella-shaped balloon similar to that used
`by Davies et a1. They concluded that the relatively simple
`umbrella system was best, significantly reducing the severity
`of
`acute
`aortic
`insufficiency without major
`acute
`complications.
`1
`There were several disadvantages of a catheter-based valve
`found by these investigators in the chronic animal model, in-
`cluding the development of significant thrombi in the base of
`the umbrella in all animals followed chronically. Most iIn-
`portantly, variable decreases in coronary flow also occurred
`in these animals. The decreased coronary flow was attributed
`
`
`
`wry”?Wfim”?QT”?
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`

`FIGURE 15-l. The Hufnagel valve, when
`assembled, consisted of a hollow plastic
`tube, the fixation rings on each end, and
`
`the polypropylene central ball.
`
`HGIIRE 15-2. The Davis valve was an in-
`vetted plastic cone anchored to the shaft
`of a 5-Fr. catheter. Note the guy wires used
`to stabilize the valve.
`
`75—PERCUTANEOUS EXPANDABLE PROSTHETIC VALVES
`
`1269
`
`
`
`
`FIGURE 75-3. The top section demonstrates the valve motion during systole and diastole. The bottom left
`is a photograph of the umbrella valve and the middle is the balloon valve. The bottom right is a picture of
`the glass cast used to manufacture the umbrella valve.
`
` i|l
`
`i.
`
`
` H»;
`;.
`
`
`Edwards Lifesciences Corporation, et al. Exhibit 1137, Paggmlgllasomswsz
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`Edwards Lifesciences Corporation, et al. Exhibit 1137, Page 6 of 12
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`75—PERCUTANEOUS EXPANDABLE PROSTHETIC VALVES
`
`1171
`
`TABLE 15-11. HIGH-RISK PATIENTS WHO MIGHT BENEFIT
`FROM PERCUTANEOIIS VALVE PLACEMENT
`
`
`Mitral regurgitation due to
`Acute myocardial infarction
`Bacterial endocarditis
`Flail mitral leaflet
`Decompensated chronic mitral regurgitation
`Aortic regurgitation due to
`Bacterial endocardiu‘s
`Decompensated chronic aortic regurgitation
`Tricuspid regurgitation due to
`Bacterial endocarditis
`Pulmonary hypertension
`
`Right ventricular dysfunction
`
`TABLE 75-3. DESIGN PROBLEMS OF PERCIITANEOUS
`VALVES
`___—__.__—__\
`Delivery sheath
`Size of sheath
`Material required to avoid ferchon
`Stiffness of sheath
`Delivery system
`Self-expanding
`Balloon expandable
`Mechanical expansion
`Type of valve
`Bioprosthetic
`Mechanical
`Polymer
`
`to the . valve leaflets covering the coronary ostia during
`diastole.
`
`Phillips at 1511.9 reported a modification of the balloon-
`mounted valve concept in 1976. Figure 75—4 displays the seg-
`mented polyurethane cusp mounted 1 cm from the distal end
`of the catheter that was used in their study. The distal end of
`the catheter contained side holes for monitoring pressure dur-
`ing the procedure. In their dog model they demonstrated a
`significant reduction in aortic diastolic pressure, pulse pres-
`sure, and left ventricular end-diastolic pressure. Coronary ar-
`tery blood flow did not fall and in fact increased slightly, with
`their balloon system.
`investigation of a balloon catheter—
`The most
`recent
`mounted valve was that of Matsubara et al. in 1992.” They
`used the valve shown in Figure 75—5. This somewhat com-
`plicated valve system consists of an 8—Fr. catheter with a latex
`balloon mounted on the catheter. Using hemodynamic eval:
`uation without angiography they demonstrated significant
`decreases in pulse pressure and left ventricular end-diastolic
`pressure as well as increases in aortic diastolic pressure. After
`placement of the device, however, the experimental animals
`still had a significant‘tachycardia and a larger pulse pressure
`than at baseline, suggesting continued aortic regurgitation.
`Unfortunately, the severity of the persistent aortic regurgita-
`tion was not quantitated by the authors.
`Although catheter-based balloon valve technology may of—
`fer some acute relief‘from valvular aortic regurgitation, it is
`not a technology that could feasibly be used over an extended
`period of time as an indwelling device.
`
`BALLOON-EXPANDABLE VALVES
`
`The success of balloon-expandable endovascular stents has
`inspired some investigators to try to develop implantable,
`
`TABLE 75-L LIMITATIONS OF CURRENT VALVE
`PROTI'IESES
`Mechanical
`Reduction in valve orifice
`Hemolysis
`Pannus formation
`Thrombotic
`Systemic emboli
`Stroke
`Complications of anticoagulafion
`Hemorrhagic stroke
`Gastrointestinal bleeding
`Infective endocarditis
`
`a
`balloon-expandable valvular prostheses. Conceptually,
`“stent” should provide a rigid frame, allowing the valve
`struts sufficient strength to remain stable during systole while
`anchoring the valve to the surrounding tissue. Following this
`premise, one should be able to develop a delivery system and
`valve'that can be delivered percutaneously from a large ar~
`tery or even trans-septally from the femoral vein. This
`method of delivery might answer the immediate needs of
`acutely ill patients or those patients at very high surgical risk
`from valvular regurgitation for valve placement (Table 75—1).
`
`DESIGN PROBLEMS OF
`PERCUTANEOIIS VMVES
`
`Current mechanical and prosthetic valves suffer from a
`number of problems (Table 75—2) including the predisposi-
`tion to thrombus formation and embolization, perivalvular
`leak, infection, difficulty sizing valve to annulus, valve de-
`generation, and pannus formation. The designer of any per-
`cutaneously placed valve will need to consider these issues
`during its design and development in order to minimize these
`problems. A high probability exists that percutaneous valves
`will be used, at least initially, as a temporizing measure in
`patients who are not acceptable candidates for surgical valve
`replacement. The long-term problems of valve degeneration
`and calcification will therefore not be as important in the sub-
`set of patients undergoing percutaneous valve insertion as a
`stabilizing procedure.
`The design of a new percutaneous valve is frought with a
`large number of problems as detailed in Table 75—3. The
`problems can be subdivided into three major categories: (1)
`the problem of a delivery sheath that will allow safe and ef-
`fective delivery of a bulky balloon and valve; (2) a balloon
`system that is capable of precisely implanting the valve must
`be manufactured; and (3) modifications of current valves or
`development of new valvular prostheses must occur.
`
`TABLE 75-4. BALLOON~EXPANDABLE VALVE
`
`
`Advantages
`Percutaneous arteriotomy
`Large expansion ratio of stent
`Approach to multiple valves with same system
`Ability to easily increase size of valve
`Disadvantages
`Closure of arteriotomy
`Technically demanding
`Possible dislodgment
`
`Myocardial ischemia
`
`
`
`t al. Exhibit 1137, Pagggvgfigasomw 584
`
`
`
`
`Edwards Lifesciences Corporation, e
`
`a
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`
`NH IHH
`
`1272
`
`VIII—VALVULOPLASTY, CONGENITAL AND PERICARDIAL HEART DISEASE
`
`
`
`
`
`HGURE 75-6. A, The stent ring is constructed of stainless-steel
`wires folded in loops. B, A porcine valve was mounted inside the
`rings and attached by means of suture. C, A view from above valve
`illustrating the intact valve with three cusps.
`
`is
`
`L Ilrll
`
`Percutaneous Delivery System
`
`Large lumen sheaths and catheters (up to 22-Fr.) are cur-
`rently used for vascular access for such procedures as cuta-
`neous perfusion devices. Such ‘a large arterial puncture is a
`major concern with any delivery system, due to the potential
`for injury to the artery, bleeding, or pseudoaneurysm for-
`mation. New technologies are emerging for the local repair
`and sealing of large arteriotomies that should aid the percu-
`taneous placement of valves. In the past, up to 25 per cent of
`arteriotomies performed for balloon valvuloplasty or cuta-
`neous perfusion devices required direct surgical closure. This
`repair if necessary, however, could be performed under local
`anesthesia and is a relatively minor surgical procedure com~
`pared to valve replacement.
`Ideally, a successful percutaneous delivery system must be
`no larger than 20 Fr. (6.6 mm) in order to be used in a large
`number of patients. In addition, a removable trochar with a
`soft distal tip Will be necessary to successfully deliver this
`guide sheath to the valve with the smallest amount of arterial
`trauma. Once the delivery sheath is appropriately positioned,
`the trochar can be removed.
`‘
`A protective sleeve covering the balloon and valve will
`
`be required in order to minimize the friction between the
`balloon-valve and the guide catheter. This sleeve might also
`serve the purposes of constraining the valve and preventing
`slippage or embolization of the valve. Alternatively, the bal-
`loon catheter itself might have a sleeve covering just the stent
`to provide similar protection. After expansion of the valve
`the balloon could be retracted into the sheath to avoid arterial
`injury associated with removal of the balloon.
`
`TABLE 75—5. BALLOON DEPLOYABLE VALVE:
`THE OPTIMAL SYSTEM
`
`
`Requirements for valve
`Minimal vascular trauma
`Must not be dislodged
`During delivery
`During balloon withdrawal
`Valve must be matched to annulus
`Valve must remain competent
`Local tissue injury avoided
`Avoid myocardial i'schemia
`
`No significant thrombosis
`
`Edwards Lifesciences Corporation, et al. Exhibit 1137, PaggMfiéfisoo383és5
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`

`75—PERCUTANEOUS EXPANDABLE PROSTHETIC VALVES
`
`1273
`
`FIGURE 75—7. A, The compressed valve and stent are shown from
`the top view. B, The stent and valve have been mounted on the
`delivery balloon. Note the plastic wedges on either side of the stent
`
`to anchor it in place.
`
`
`TABLE 75-6. VALVE CONSTRUCTION DESIGN
`
`REQUIREMENTS
`Orifice
`Primary
`Central blood flow
`Secondary
`Area between Primary orifice and OCCIUder
`Tefiae-zybeMeen ocduder and aortic wall
`Seating Patterns
`Overlappmg
`Full orifice
`valve types
`Mechanical
`Homograft
`Xenograft
`Materials “58d
`Megzwed
`gitaniflsme
`Alloys
`Stemte 21
`Elgiloy
`Pyrollite
`POIYmers
`Tefl‘f“
`
`‘
`
`1
`
`'
`
`.
`
`’
`
`'
`
`Polypropylene
`’
`
`
`DELIVERY BALLOON CHARACTERISTICS
`
`-
`
`An irnportant issue central to the success of percutaneous
`_
`_
`‘
`valve placement Wlll be the deVice or system used to implant
`the valve. The valve could be self-expanding, expandable
`by some mechanical device as yet undefined, or balloon ex-
`pandable. In order to be practical, some form of a balloon-
`expandable system
`probably be required in order for
`such a system to be Widely employed._A balloon-expandable
`system offers the advantages and disadvantages listed in
`Table 75—4. The advantages include the ability to use a rela-
`tively small arterial puncture or arteriotomy in the placement
`of an introducer sheath. Additionally, the use of a balloon
`system will allow expansion of the device from a much
`smaller compressed state to the larger fully deployed state.
`This could result in an expansion ratio between three and ten
`times the compressed diameter. Such an expansion ratio
`might even allow percutaneous placement of large mitral and
`tricuspid valves. Such expansion ratios need not require an
`expandable metal mesh, but might occur in the form of a
`single ring designed much like a hose clamp that opens; even
`self—expanding alloys might be utilized if correctly designed.
`Placement techniques must be devised to assure site—specific
`localization and stabilization of such a device as well as an
`orientation that is coaxial to blood flow. In most cases these
`valves would be placed for severe valvular regurgitation, aS'
`suring a large-volume, high-velocity jet at the site of intended
`
`;
`;
`
`3
`
`5
`
`1_
`_
`:
`5
`;;
`
`E
`:1
`i
`
`z
`
`
`
`
`Edwards Lifesciences Corporation, et al. Exhibit 1137, Paggmlgllasomsfise
`
`Edwards Lifesciences Corporation, et al. Exhibit 1137, Page 9 of 12
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`

`

`
`
`1274
`
`VIII—VALVULOPLASTY, CONGENITAL AND PERICARDIAL HEART DISEASE
`
`w
`
`
`
`
`FIGURE 15-8. A, The expanded balloon with the stent still in
`place. The arrows indicate the elastic blocks used to keep the valve
`in place. B, The fully expanded valve is seen from the top.
`
`\/
`
`
`
`bv
`
`placement. Such a large blood volume may well require a
`secondary balloon or a novel stabilization method in order to
`assure exact valve placement. In addition, this delivery sys-
`tem will need to be capable of angiographic injections to de-
`termine exact location of the valve and to assure that coro-
`nary ostia are not compromised. Several options are possible
`for such a delivery catheter, including a short segment of
`catheter distal to the valve prosthesis for sampling pressures
`and performing the angiographic injections.
`In order to successfully deploy a percutaneous valve, the
`delivery system will need to meet several criteria (Table 75—
`5). The first will be that the valve is not displaced from the
`balloon during delivery. Second, the balloon must expand to
`a large enough diameter to securely anchor the valve in place.
`Third, retraction of the balloon must not dislodge the valve.
`And fourth, the delivery balloon must not damage surround-
`ing tissue.
`The delivery balloon could be constructed of multiple bal-
`loons placed on a single catheter, although hourglass con-
`struction of the variety currently employed by the lnoue bal-
`loon may be preferable. Multilobed balloons do allow a
`smaller diameter of the deflated balloon but are unstable in
`
`high-flow fields such as one would find in mitral or aortic
`regurgitation.
`The hourglass balloon might have two inflation lumens—
`one for the distal balloon and a second for the proximal bal-
`loon and valve. This technique will allow the valve to be im-
`planted only after the distal balloon has first been anchored
`in place at the site of the valve annulus. This type of balloon
`would also resulbin less damage to surrounding tissue, since
`the largest diameter of such a balloon would be at its center,
`where the valve was situated. Additionally, this single bal-
`loon would be less likely to become entangled in the valve
`and dislodge it. Finally, the hourglass shape is more adapt-
`able to large and small diameters, allowing a single balloon
`design to function as the primary delivery device for all per-
`cutaneous valve implants.
`
`VALVE CONSTRUCTION
`
`The specific material(s) from which a percutaneously
`placed valve is constructed is an area requiring further eval-
`
`Edwards Lifesciences Corporation, et al. Exhibit 1137, Pagemfigasomsfiw
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`Edwards Lifesciences Corporation, et al. Exhibit 1137, Page 10 of 12
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`

`
`
`1276
`
`VIII—VALVULOPLASTY, CONGENITAL AND PERICARDIAL HEART DISEASE
`
`that can be “floated” into the ventricle, since it is less likely
`to be caught inbetween ,chordal structures than a system that
`is placed over a wire.
`‘
`
`CURRENT INVESTIGATIONS
`
`The most exciting published work in this area to date is
`the investigationsby Andersen et at. from Denmark pub-
`lished in 1992.13 They reported on their work on developing
`a transluminal' implantable heart valve. They began their in-
`vestigations in 1987 and have developed an exciting catheter—
`based technique that has been initially evaluated in a porcine
`model. Using 0.55-mm surgical grade stainless-steel wire,
`they formed a steel mesh 14 mm in length upon which por-
`cine aortic valves were mounted with suture (Fig. 7546). This
`allowed the stent to be com ressed to 12 mm when folded
`and expanded to 32 mm wia the delivery balloon (Fig. 75—
`7). A 41-Fr. introducer sheath was used to place the valve
`from a surgically created arteriotomy site (Fig. 75—8). The di-
`rect introduction was required because of the small femoral
`arteries of the pigs they used for this evaluation. Placement
`was guided both by fluoroscopy and by echocardiography,
`although transthoracic echocardiography was abandoned be—
`cause the echogenic nature of this valve did not allow accu-
`rate imaging of the valve. Figure 75—9 demonstrates angio-
`graphic images from animals that had subcoronary and
`supracoronary implantation of the valve.
`Although all of the protocol animals survived the initial
`implantation, two of the seven animals studied died of pro-
`gressive left ventricular dysfunction secondary to myocardial
`ischemia. At necropsy no animals demonstrated dissection or
`hematoma. Three of four animals studied did demonstrate
`restriction of coronary flow. Finally, two of the seven valves
`still had mild degrees of aortic regurgitation.
`These investigations also were very creative in the creation
`of a delivery system. They used three balloons, each 15 mm
`in diameter and 70 mm in length, with small blocks placed
`on the balloon to anchor the stent in place.
`Although the above study presents only early data illus-
`trating the large amount of work re uired before a device
`such as this can be used, it illustrates 3121f such devices await
`only the focused evaluation and improvement of a few in-
`vestigators. Without question, within the next few years de-
`vices such as this will be used in selected high-risk patients
`for the treatment of valvular disease.
`
`7 CONCLUSIONS
`
`The development of percutaneous techniques for treatment
`of cardiovascular diseases will continue to provide us with
`
`new methods of stabilizing and treating patients. It is ex-
`tremely likely that one of these technologies will be percu-
`taneously implanted heart valves. Most certainly the treat-
`ment of acute aortic insufficiency will be possible; treatment
`of other regurgitant lesions as well is likely. In 10 years we
`shall very probably look back on the pioneering work de-
`scribed above in the same way we respect the work of Huf~
`nagel, Gruentzig, and Palrnaz today. Certainly, heart valves
`will undergo radical changes in design in the decade.
`
`References
`
`1. Hufnagel CA, Harvey WP: The surgical correction of aortic re-
`gurgitation. Preliminary report. Bull Georgetown Univ Med
`Center 6:3—6, 1953.
`2. Hufnagel CA, Harvey WP, Rabil P], McDermott TF: Surgical
`correction of aortic insufficiency. Surgery 35:673—683, 1954.
`3. HarkenDE, Soroff HS, Taylor W], Lefemine AA, Gupta SK,
`Lunzer» S: Partial and complete prosthesis in aorta insuffi-
`ciency. I Thorac Cardiovasc Surg 40:744—762, 1960.
`4. Grunkemeier GL, Starr A, Rahimtoola SH: Prosthetic heart valve
`performance: Long term follow-up. Curr Prob Cardiol 6:333-
`406, 1992.
`’
`5. Fessatidis I, Hackett D, Oakley CM, et a1: Ten-year clinical eval—
`uation of isolated mitral valve and double valve replacement.
`Ann Thorac Surg 43:368~372, 1987.
`6. Perier P, Deloche A, Chanvaud S, et al: Clinical comparison of
`mitral valve replacement using porcine, Starr and Bjork pros-
`theses. ] Cardiovasc Surg 3:359—362, 1988.
`7. Davies H: Catheter mounted valve for temporary relief of aortic
`insufficiency. Lancet 1:250, 1965.
`8. Moulopolous SD, Anthopolous L, Stamatelopolous S, Stefado-
`rous M: Catheter-mounted aortic valves 11:423—430, 1971.
`9. Phillips 5], Ciborski M, Freed PS, Cascade PN, Jaron D: A tem-
`porary catheter—tip aortic valve: Hemodynarnic effects on ex-
`perimental acute aortic insufficiency. Ann Thorac Surg 21:
`134—137, 1976.
`10. Matsubara T, Yamazoe M, Tamura Y, Ohshima M, Yamazaki Y,
`Suzuki M, lzumi T, Shibata A: Niigata, Japan. Balloon catheter
`with check valves for experimental relief of acute aortic re-
`gurgitation. Am Heart] 124:1002—1008, 1992.
`11. Lo HB, Herold M, Reul H, et al: A tiicuspid polyurethane heart
`valve as an alternative to mechanical prostheses or biopros—
`theses. Trans Am Soc Artif Intern Organs 34:839—844, 1988.
`12. Boretos IW, Poirer RA: Aortic heart valve catheter. United States
`Patent (No. 4.056.854), 1977.
`13. Andersen HR, Knudsen LL, Hasenkam JM: Transluminal im—
`plantation of artificial heart valves. Description of a new ex-
`pandable aortic valve and initial results with implantation by
`catheter technique in closed chest pigs. Eur Heart I 1327047
`708, 1992.
`
`Edwards Lifesciences Corporation, et al. Exhibit 1137, Pagemfiéasomswsg
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