JACC Vol. 30, No. 7
`December 1997:1847–52
`
`1847
`
`PEDIATRIC CARDIOLOGY
`
`Use of Balloon-Expandable Stents for Coarctation of the Aorta: Initial
`Results and Intermediate-Term Follow-Up
`
`MAKRAM R. EBEID, MD, FACC,* LOURDES R. PRIETO, MD, LARRY A. LATSON, MD, FACC
`Cleveland, Ohio
`
`Objectives. In this study we report our preliminary results and
`intermediate-term follow-up (up to 3.5 years) of stent implanta-
`tion for coarctation of the aorta (COA).
`Background. Balloon angioplasty has gained acceptance as a
`modality of treatment for COA. Some patients do not respond
`optimally to balloon angioplasty alone. Balloon-expandable stents
`have been used in pulmonary arteries and large systemic arteries
`such as the femoroiliac vessels, with a significant improvement in
`vessel patency and a reduction in the pressure gradient compared
`with balloon angioplasty alone.
`Methods. Nine patients (>10 years old) with COA in whom
`balloon dilation alone was thought to be ineffective underwent
`stent implantation. Seven patients had a previous operation or
`balloon dilation, or both, to relieve their coarctation but had a
`significant residual/recurrent gradient.
`Results. At the time of stent implantation, the systolic and
`mean gradients decreased from a mean (6SEM) of 37 6 7 and
`14 6 3 mm Hg to 4 6 1 and 2 6 0.6 mm Hg, respectively (p <2
`
`0.002). The coarctation diameter increased from a mean of 9 6 1
`to 15 6 1 mm (p < 0.002). The patients have been followed for up
`to 42 months (mean 18, median 13) with no complications; the
`stents remain in position with no fracture. One patient underwent
`further successful dilation 3 years after stent implantation be-
`cause of an exercise-induced gradient. No other intervention has
`been required. The systolic gradient at latest follow-up is 7 6
`2 mm Hg. Only two (a 44-year old with diabetes and a 50-year old
`with long-standing hypertension) of five patients previously re-
`quiring antihypertensive treatment still remain on medications
`for blood pressure control.
`Conclusions. The use of stents in COA is a feasible alternative
`to surgical repair or balloon angioplasty in selected patients with
`an effective gradient reduction. Intermediate-term follow-up
`shows excellent gradient relief, with no complications in this
`group of patients.
`
`(J Am Coll Cardiol 1997;30:1847–52)
`©1997 by the American College of Cardiology
`
`Balloon dilation has gained acceptance in the treatment of
`coarctation of the aorta (COA). It has been advocated as the
`therapy of choice in postoperative coarctation (1–4) and as an
`acceptable alternative to surgical repair in native coarctation
`(5,6). However, a significant number of patients develop
`recoarctation after balloon angioplasty (7–9). To improve the
`results of balloon angioplasty, patients .10 years of age with
`COA, evaluated at the Cleveland Clinic since 1993, were
`considered for stent implantation. We report our initial expe-
`rience and short- to intermediate-term follow-up of these
`patients.
`
`Methods
`Patients. All patients undergoing stent implantation for
`COA at the Cleveland Clinic Foundation between January
`1993 and November 1996 were included in the study. There
`were nine patients (two males and seven females) between 14
`
`From the Department of Pediatric Cardiology, Cleveland Clinic Foundation,
`Cleveland, Ohio.
`Manuscript received February 17, 1997; revised manuscript received July 28,
`1997, accepted August 27, 1997.
`*Present address and address for correspondence: Dr. Makram R. Ebeid,
`University of Mississippi School of Medicine, Children’s Hospital, 2500 North
`State Street, Jackson, Mississippi 39216. E-mail: mebeid@ped.umsmed.edu.
`
`and 63 years old. Their weight ranged from 47 to 133 kg
`(median 61).
`Catheterization technique. Informed consent was obtained
`from all the patients, or the parent, if the patient was a minor.
`The study was initiated after approval of the Institutional
`Review Board of the Cleveland Clinic Foundation. After 1
`year, stent implantation was no longer considered investiga-
`tional and only the patient’s (or parent’s) informed consent
`was required. All patients underwent routine cardiac catheter-
`ization under general anesthesia. Hemodynamic data, includ-
`ing systolic and mean gradients, and angiographic measure-
`ment of the coarctation site, the proximal aorta and the
`descending aorta at the level of the diaphragm were acquired.
`With the aid of a guide catheter, a long stiff guide wire was
`placed across the stenotic area. This was used to position a
`10F, 11F or 12F sheath and dilator across the coarctation site.
`The dilator was then removed and a Palmaz stent (P308, 3 cm
`long and 3.4 mm unexpanded diameter; Johnson & Johnson
`Interventional Systems Co.), mounted on a balloon dilation
`catheter (12, 15, 18 or 20 mm Z-med or Tyshack, NuMed,
`Inc.), was advanced inside the sheath to the stenotic area. The
`balloon size chosen was the nearest size equal to the diameter
`of the transverse aortic arch not to exceed the diameter of the
`descending aorta at the level of the diaphragm (maximum
`20 mm). The long sheath was withdrawn to expose the
`
`©1997 by the American College of Cardiology
`Published by Elsevier Science Inc.
`
`0735-1097/97/$17.00
`PII S0735-1097(97)00408-7
`
`Edwards Lifesciences Corporation, et al. Exhibit 1013, p. 1 of 6
`
`

`

`1848
`
`EBEID ET AL.
`STENTS IN COARCTATION
`
`JACC Vol. 30, No. 7
`December 1997:1847–52
`
`Figure 1. A, Angiogram of the coarctation
`before angioplasty. B, After balloon angio-
`plasty, the coarctation size increased from 7
`to 9.5 mm, with a residual gradient of
`20 mm Hg. C, After stent implantation, there
`was an increase in the coarctation size to
`12 mm, with a decrease in the gradient to
`4 mm Hg. See text for details.
`
`balloon-mounted stent, which was carefully positioned at the
`coarctation site. The balloon was then inflated using the
`recommended pressure (4 to 5 atm). In some instances, further
`inflation of the proximal and distal ends of the balloon was
`done to ensure flaring of the stent ends. Repeat hemodynamic
`and angiographic data were acquired (Fig. 1).
`Anticoagulation. We have maintained our patients on as-
`pirin for at least 1 year after the procedure to avoid platelet
`aggregation. Because this is a high pressure, high flow area, it
`was not thought necessary to use warfarin to anticoagulate the
`patients.
`Follow-up. All patients had follow-up at 1 month and
`yearly thereafter. This included a complete history and physical
`examination, blood pressure measurements in all extremities
`and a chest roentgenogram. An echocardiogram and an exer-
`cise test were obtained at the discretion of the referring
`cardiologist. To assess any residual stenosis across the coarc-
`tation, the higher value of the arm and leg blood pressure
`measurement gradients or the Doppler-derived corrected gra-
`dients (10) was used.
`Data analysis. The pre-stent and post-stent implantation
`data were compared using the paired Student t test. A p value
`#0.05 was considered statistically significant. The data are
`expressed as the mean value 6 SEM (except for the follow-up
`period, which is expressed as the median value because of the
`skewed distribution). Clinical success was considered to be a
`
`gradient reduction across the coarctation segment
`#20 mm Hg at rest.
`
`to
`
`Results
`A total of 10 procedures involving stent implantation were
`performed in nine patients (Table 1); one patient required
`further balloon dilation of the stent 3 years after implantation.
`Seven patients had previous surgical repair of the coarctation;
`six had previous balloon dilation of the coarctation. Balloon
`angioplasty was performed immediately before stent implan-
`tation in four patients. When hemodynamic assessment dem-
`onstrated the persistence of an unacceptable gradient despite
`adequate dilation, a decision was made to implant a stent. Two
`patients with native coarctation had stent placement as an
`initial procedure; one patient with severe scoliosis and restric-
`tive lung disease was considered high surgical risk and the
`other patient refused surgical intervention. The balloon dila-
`tion size was 15 mm in four patients, 18 mm in three, 20 mm in
`two and 12 mm in one. The last patient is a young adult of
`small build whose descending aorta measured 11 mm. The
`systolic and mean gradients (Table 2) decreased significantly
`from 37 6 7 to 4 6 1 mm Hg and 14 6 3 to 2 6 0.6 mm Hg,
`respectively, after stent implantation. The size of the coarcta-
`tion site increased from 9 6 1 to 15 6 1 mm (p , 0.002). Two
`patients had a hypoplastic distal transverse arch where a stent
`
`Edwards Lifesciences Corporation, et al. Exhibit 1013, p. 2 of 6
`
`

`

`JACC Vol. 30, No. 7
`December 1997:1847–52
`
`Table 1. Patient Data
`
`Pt
`No.
`
`Age (yr)/
`Gender
`
`Weight
`(kg)
`
`1
`2
`
`3
`
`4
`
`5
`6
`
`7
`
`14/F
`17/F
`
`18/F
`
`63/M
`
`45/F
`28/F
`
`19/F
`
`61
`48
`
`61
`
`54
`
`133
`71
`
`62
`
`18/M
`
`47
`
`8
`
`9
`
`Diagnosis
`
`Surgical Repairs
`
`COA, HTN, hypoplastic transverse arch
`COA distal to left subclavian, mild
`HTN
`Severe AS, coarctation
`
`COA, HTN, scoliosis, restrictive lung
`disease
`COA, HTN, diabetes mellitus
`COA, HTN
`
`AS, AI, COA, hypoplastic transverse
`arch
`COA, VSD, CVA after surgical repair
`
`Patch graft, then tube graft
`End to end anastomosis
`
`End to end anastomosis, Ross
`procedure
`None
`
`End to end anastomosis
`End to end anastomosis, PDA
`ligation
`End to end anastomosis
`
`EBEID ET AL.
`STENTS IN COARCTATION
`
`1849
`
`Previous Balloon
`Dilation
`1
`1
`
`1 of AS, COA
`
`2
`
`1
`1
`
`1 of AS, COA
`
`Balloon Dilation
`Immediately Before
`Stent Placement
`1
`1
`
`1
`
`2
`
`2
`1
`
`2
`
`Anti-HTN
`Medications
`
`BB
`None
`
`None
`
`ACEI
`
`BB
`BB
`
`None
`
`2
`
`2
`
`2
`
`2
`
`None
`
`VSD closure, two COA
`surgical repairs, including
`end to end anastomosis and
`subclavian turndown
`ACEI, CCB
`None
`COA, HTN
`70
`50/F
`ACEI 5 angiotensin-converting enzyme inhibitor; AI 5 aortic insufficiency; AS 5 aortic stenosis; BB 5 beta-blocker; CCB 5 calcium channel blocker; COA 5
`coarctation of the aorta; CVA 5 cerebrovascular accident; F 5 female; HTN 5 hypertension; M 5 male; PDA 5 patent ductus arteriosus; Pt 5 patient; VSD 5
`ventricular septal defect; 1 5balloon angioplasty or valvuloplasty, or both; 2 5no previous balloon angioplasty.
`
`was placed with adequate gradient relief (Fig. 2). The end of
`the stent extended slightly into the orifice of the left subclavian
`artery or the left common carotid artery in these patients.
`Immediate post-stent angiography showed normal flow to both
`vessels.
`Follow-up. No patient has been lost to follow-up. Detailed
`medical evaluations are available up to 42 months after the
`procedure (average 18, median 13). Chest roentgenograms
`have shown all stents to be in good position with no fracture or
`dislodgment. No patient has reported any symptoms of dizzi-
`ness, numbness, unexplained weakness or claudications. There
`were no episodes suggestive of thromboembolic phenomena.
`
`No clinically detectable femoral artery problems were encoun-
`tered either immediately after the procedure or at follow-up.
`Before stent implantation, five patients had hypertension
`requiring antihypertension treatment. Only two patients (a
`45-year old diabetic patient and a 50-year old patient with
`long-standing hypertension) still require antihypertension
`treatment despite elimination of the gradient after the stent
`implantation. One patient who previously had exercise-
`induced hypertension had a normal blood pressure exercise
`response 1 year after stent implantation. Another patient, with
`a 15-mm Hg gradient at rest, who is a competitive athlete,
`developed an 82-mm Hg gradient at peak exercise testing at 3-
`
`Table 2. Hemodynamic Findings Before and After Stent Implantation
`Before Stent Implantation
`
`After Stent Implantation
`
`Coa Size
`(mm)
`
`Coa/Prox
`Ao
`
`Pt No.
`
`Coa/DAo
`
`Cath Systolic
`Gradient
`(mm Hg)
`
`Cath Mean
`Gradient
`(mm Hg)
`
`Coa Size
`(mm)
`
`Coa/Prox
`Ao
`
`Coa/DAo
`
`Cath Systolic
`Gradient
`(mm Hg)
`
`Cath Mean
`Gradient
`(mm Hg)
`
`Follow-Up
`
`Gradient
`(mm Hg)
`
`Period
`(mo)
`
`9
`7
`9
`4
`12
`8
`10
`9
`15
`9 6 1
`
`0.57
`0.6
`0.41
`0.41
`0.5
`0.45
`0.34
`0.28
`0.57
`0.52
`0.62
`0.47
`0.5
`0.47
`0.84
`0.84
`0.58
`0.56
`0.5 6 0.03 0.55 6 0.05
`
`44
`30
`36
`86
`35
`36
`18
`17
`28
`37 6 7
`
`1
`2
`3
`4
`5
`6
`7
`8
`9
`Mean 6
`SEM
`*p , 0.002 versus pre-stent values. †Value given is postballoon redilation 3 years after stent implantation. ‡Because of the skewed distribution of the follow-up
`period, average (and median) values are given. Follow-up gradients are the higher of the blood pressure measurements or the Doppler-estimated gradients. Cath 5
`catheterization; Coa 5 coarctation; DAo 5 descending aorta at the level of the diaphragm; Prox Ao 5 proximal aorta.
`
`21
`25
`10
`12
`12
`32
`4
`4
`14
`14 6 3
`
`13
`12
`14
`16
`17
`14
`17
`11
`19
`15 6 1*
`
`0.83
`0.87
`0.71
`0.71
`0.78
`0.7
`1.2
`1
`0.81
`0.74
`1.1
`0.82
`0.89
`0.89
`1
`1
`0.73
`0.7
`0.82 6 0.04* 0.89 6 0.06*
`
`8
`4
`8
`0
`12
`2
`2
`0
`2
`4 6 1*
`
`4
`5
`0
`0
`2
`0
`2
`1
`2
`2 6 0.6*
`
`0†
`18
`9
`0
`16
`0
`9
`12
`0
`7 6 2*
`
`40
`42
`34
`21
`8
`13
`1
`1
`1
`18 (13)‡
`
`Edwards Lifesciences Corporation, et al. Exhibit 1013, p. 3 of 6
`
`

`

`1850
`
`EBEID ET AL.
`STENTS IN COARCTATION
`
`JACC Vol. 30, No. 7
`December 1997:1847–52
`
`Figure 2. A, The angiogram before stent de-
`ployment demonstrates the presence of coarc-
`tation with a hypoplastic transverse arch. B,
`After stent deployment, the angiogram demon-
`strates the position of the stent extending to
`cover part of the transverse arch. There is no
`angiographic evidence of flow obstruction in
`the arch vessels.
`
`years follow-up. At 38 months after stent implantation, she
`underwent a repeat cardiac catheterization and stent redilation
`using an 18-mm balloon with elimination of the rest gradient
`(15-mm balloon was used in the initial
`implantation). A
`follow-up stress test revealed a maximal gradient of 27 mm Hg
`at peak exercise. This patient’s stent spanned across the left
`subclavian artery and part of the left common carotid artery at
`initial implantation because of a hypoplastic transverse arch.
`Repeat angiography 3 years later demonstrated normal flow to
`both the left subclavian and left common carotid arteries (Fig.
`3). At latest follow-up, the mean (6SEM) rest gradient in all
`patients across the coarctation site, taking the higher value of
`the blood pressure measurements or Doppler-estimated cor-
`rected gradients, is 7 6 2 mm Hg (median 9, ,20 in all
`patients).
`
`Discussion
`Balloon-expandable stents have been used in the vascular
`system since the mid-1980s (11–14). Shortly after the initial
`successful experience with balloon-expandable stents in the
`iliac arteries, these stents were introduced in the management
`of stenotic lesions in congenital heart disease both postopera-
`tively and as an alternative to surgical repair (15). Their
`usefulness has been demonstrated in a number of stenotic
`lesions. In 1993, O’Laughlin et al. (16) reported the early and
`intermediate-term follow-up of stents implanted in the pulmo-
`nary arteries and the venous system to relieve obstruction.
`Their results demonstrated that the stents retained their
`efficacy and continued to provide beneficial effects with no
`significant complications. The use of stents has been expanded
`
`Figure 3. A, Coarctation and mild hypoplasia of
`the distal transverse arch evident before stent
`deployment. Despite the interposition of a tube
`graft (open arrow), a 44-mm Hg gradient per-
`sisted. B, Stent deployed partially covering the
`left subclavian and common carotid arteries.
`The gradient decreased to 8 mm Hg, and the
`size of the coarctation increased from 9 to
`13 mm. C, Three years later, the angiogram
`demonstrates normal flow in the left subclavian
`and common carotid arteries. Note the pres-
`ence of a small neointimal layer. LC 5 left
`common carotid artery; LSC 5 left subclavian
`artery. See text for details.
`
`Edwards Lifesciences Corporation, et al. Exhibit 1013, p. 4 of 6
`
`

`

`JACC Vol. 30, No. 7
`December 1997:1847–52
`
`EBEID ET AL.
`STENTS IN COARCTATION
`
`1851
`
`to involve other stenotic lesions, such as right ventricle to
`pulmonary artery homografts (17). Animal studies in 1994
`demonstrated the feasibility of stents in treating experimental
`coarctation. Follow-up of animals with stents showed contin-
`ued relief of the coarctation gradient with no evidence of
`intraluminal thrombosis (18). Encouraging initial and short-
`term results have been reported in a small number of patients
`who underwent stent implantation for COA (19–21). Our
`results show that the beneficial effects appear to persist up to
`3.5 years after stent implantation.
`Recoarctation after balloon angioplasty has been seen in
`18% to 31% of patients with native coarctation (7,8) and in 9%
`to 80% (9,22) of those with postoperative coarctation. Recur-
`rence was found to depend on the age of the patient, the
`nature of the lesion and size of the balloon used. Late
`follow-up of patients treated with balloon angioplasty showed
`that 32% of the patients with recurrent coarctation had not
`had adequate gradient relief (,20 mm Hg) at the initial
`angioplasty procedure, despite an adequate balloon/isthmus
`ratio (8). Two possible mechanisms of recurrence include
`elastic recoil of the tissue and the presence of long segment
`narrowing, especially the transverse aortic arch. Intravascular
`stents can maintain the patency of a stenotic lesion by elimi-
`nating the elastic recoil of the tissue and can extend over a
`relatively long segment of stenosis.
`In this study, we report our initial experience and short- to
`mid-term follow-up of nine patients. In four of our patients,
`initial balloon angioplasty performed in the same cardiac
`catheterization failed to satisfactorily eliminate the gradient
`(Fig. 1). In these patients the stenosis was dilatable, but recoil
`of the dilated segment resulted in persistence of an unaccept-
`able gradient. Stents provide support to prevent recoil of the
`coarctation segment; thus, long-term enlargement of the ste-
`notic site is achieved. As more experience and confidence in
`this procedure are gained, it may be possible to select patients
`who should have a stent implanted without immediate balloon
`angioplasty beforehand. This will give the advantages of short-
`ening the procedure and avoiding wire manipulation in a
`freshly dilated segment (21).
`Extension of a stent into the orifices of the branches of the
`aortic arch is a concern, as the struts can cause obstruction to
`the flow in major vessels. In adult-size patients, however, the
`struts of a dilated stent are very small relative to the diameter
`of the subclavian and carotid arteries. In two of our patients
`with a hypoplastic distal transverse arch, a stent extended
`slightly over the orifice of the left common carotid artery or left
`subclavian artery, or both. Immediate post-stent angiography
`demonstrated no flow obstruction to any of these vessels (Fig.
`2B and 3B). Repeat angiography 3 years after stent implanta-
`tion in one of these patients demonstrated no flow obstruction
`in either vessel (Fig. 3C). No patient has complained of any
`symptoms suggestive of limb ischemia or decreased cerebral
`blood flow. Despite the encouraging results, longer follow-up
`of these patients is required before definite conclusions can be
`made.
`
`Redilation of stents. The incidence of significant restenosis
`in previously placed stents in the branch pulmonary arteries
`has been reported to be low (3%) (23). Redilation of stents in
`the branch pulmonary arteries has been successful up to 3
`years after implantation. However, there continues to be
`concern about the frequency of success or safety of redilation
`of previously implanted stents. The data on redilation of stents
`in animal models of coarctation remain conflicting. In one
`study (18), redilation of stented coarctation 6 months after
`initial implantation was successful with no untoward sequelae.
`However, in a canine puppy model for coarctation, Mendel-
`sohn et al. (24) reported aortic dissection in two of seven
`animals during redilation of previously implanted stents. The
`success of redilation of stents in coarctation sites 3 years after
`implantation has not been previously demonstrated in humans.
`Because the results of redilation are not yet established, the
`selection of patients in our center is limited to those in whom
`the stent can be dilated at the initial implantation to a diameter
`large enough that the growth of the patient would not
`necessarily result in relative stent stenosis. In this study, one
`patient underwent successful redilation 3 years after implan-
`tation with no complications. The balloon used was 18 mm
`(initial implantation was done using a 15-mm balloon). This
`allowed further expansion of the stent and elimination of a
`residual waist.
`Conclusions. In selected patients with COA, stent implan-
`tation may be a feasible alternative to relieve stenosis.
`Follow-up of these patients up to 3.5 years has demonstrated
`continued gradient relief.
`
`We thank Carolyn Apperson-Hansen, MStat for reviewing the statistical analysis
`and rendering advice.
`
`References
`1. Anjos R, Quershi SA, Rosenthal E, et al. Determinants of hemodynamic
`results of balloon dilation of aortic recoarctation. Am J Cardiol 1992;69:
`665–71.
`2. Kan JS, Whilte RI, Mitchell SE, Farmlett EJ, Donahoo JS, Gardner TJ.
`Treatment of restenosis of coarctation by percutaneous transluminal angio-
`plasty. Circulation 1983;68:1087–94.
`3. Lock JE, Keane JF, Fellows KE. The use of catheter intervention procedures
`for congenital heart disease. J Am Coll Cardiol 1986;7:1420–3.
`4. Rao PS, Wilson AD, Chopra PS. Immediate and follow-up results of balloon
`angioplasty of postoperative recoarctation in infants and children. Am
`Heart J 1990;120:1315–20.
`5. Rao PS. Balloon angioplasty of aortic coarctation: a review. Clin Cardiol
`1989;12:618–28.
`6. Rao PS, Galal O, Smith PA, Wilson A. Five- to nine-year follow-up results
`of balloon angioplasty of native coarctation in infants and children. J Am
`Coll Cardiol 1996;27:462–70.
`7. Gersony WM. Coarctation of the aorta. In: Adams FH, Emmanouilides GC,
`Riemenschneider TA, editors. ‘Moss’ Heart Disease in Infants, Children and
`Adolescents. 4th ed. Baltimore: William & Wilkins, 1989:243–55.
`8. Mendelsohn AM, Lloyd TR, Crowley DC, Sandhu SK, Kocis KC, Beekman
`RH. Late follow-up of balloon angioplasty in children with a native
`coarctation of the aorta. Am J Cardiol 1994;74:696–700.
`9. Rao PS. Balloon angioplasty for aortic recoarctation following previous
`surgery. In: PS Rao, editor. Transcatheter Therapy in Pediatric Cardiology.
`New York: Wiley-Liss, 1993:206–8.
`
`Edwards Lifesciences Corporation, et al. Exhibit 1013, p. 5 of 6
`
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`

`1852
`
`EBEID ET AL.
`STENTS IN COARCTATION
`
`JACC Vol. 30, No. 7
`December 1997:1847–52
`
`10. Snider AR, Serwer GA. Echocardiography in Pediatric Heart Disease.
`Chicago: Year Book Medical, 1990:100.
`11. Palmaz JC, Richter GM, Noeldge G, et al. Intraluminal stents in atheroscle-
`rotic iliac artery stenosis: preliminary report of a multicenter study. Radiol-
`ogy 1988;168:727–31.
`12. Palmaz JC, Garcia OJ, Schatz RA, et al. Placement of balloon-expandable
`intraluminal stents in iliac arteries: first 171 procedures. Radiology 1990;
`174(Pt.2):969–75.
`13. Palmaz JC, Encarnacion CE, Garcia OJ, et al. Aortic bifurcation stenosis:
`treatment with intravascular stents. Vasc Interv Radiol 1991;2:319–23.
`14. Ing FF, Goldberg B, Siegel DH, Trachtman H, Bierman FZ. Arterial stents
`in the management of neurofibromatosis and renovascular hypertension in a
`pediatric patient: case report of a new treatment modality. Cardiovasc Interv
`Radiol 1995;18:414–8.
`15. Mullins CE, O’Laughlin MP, Vick GW 3d, et al. Implantation of balloon-
`expandable intravascular grafts by catheterization in pulmonary arteries and
`systemic veins. Circulation 1988;77:188–99.
`16. O’Laughlin MP, Slack MC, Grifka RG, Perry SB, Lock JE, Mullins CE.
`Implantation and intermediate-term follow-up of stents in congenital heart
`disease. Circulation 1993;88:605–14.
`17. Powell AJ, Lock JE, Keane JF, Perry SB. Prolongation of RV-PA conduit
`
`life span by percutaneous stent implantation: intermediate-term results.
`Circulation 1995;92:3282–8.
`18. Morrow WR, Smith VC, Ehler WJ, VanDellen AF, Mullins CE. Balloon
`angioplasty with stent implantation in experimental coarctation of the aorta.
`Circulation 1994;89:2677–83.
`19. Redington AN, Hayes AM, Ho SY. Transcatheter stent implantation to treat
`aortic coarctation in infancy. Br Heart J 1993;69:80–2.
`20. Suarez de Lezo J, Pan M, Romero M, et al. Balloon-expandable stent repair
`of severe coarctation of aorta. Am Heart J 1995;129:1002–8.
`21. Bulbul ZR, Bruckheimer E, Love JC, Fahey JT, Hellenbrand WE. Implan-
`tation of balloon-expandable stents for coarctation of the aorta: implantation
`data and short-term results. Cathet Cardiovasc Diagn 1996;39:36–42.
`22. Hellenbrand WE, Allen HD, Golinko RJ, Hagler DJ, Lutin W, Kan J.
`Balloon angioplasty for aortic recoarctation: results of the Valvuloplasty
`and Angioplasty of Congenital Anomalies Registry. Am J Cardiol 1990;
`65:793–7.
`23. Ing FF, Grifka RG, Nihill MR, Mullins CE. Repeat dilation of intravascular
`stents in congenital heart defects. Circulation 1995;92:893–7.
`24. Mendelsohn AM, Dorostkar PC, Moorehead CP, et al. Stent redilation in
`canine models of congenital heart disease: pulmonary artery stenosis and
`coarctation of the aorta. Cathet Cardiovasc Diagn 1996;38:430–40.
`
`Edwards Lifesciences Corporation, et al. Exhibit 1013, p. 6 of 6
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