Update on the Talent aortic stent-graft:
`A preliminary report from United States phase I
`and II trials
`
`Frank J. Criado, MD,a Eric P. Wilson, MD,a Ronald M. Fairman, MD,b Omran Abul-Khoudoud, MD,a
`and Eric Wellons, MD,a Baltimore, Md, and Philadelphia, Pa
`
`Purpose: Phase I and phase II trials were conducted to determine the safety and efficacy of the Talent aortic stent-graft
`(Medtronic World Medical, Sunrise, Fla) in the treatment of infrarenal abdominal aortic aneurysms (AAA). This is a pre-
`liminary report of the technical results and 30-day clinical outcome of these trials.
`Methods: Multicenter prospective trials were conducted to test the Talent stent-graft in high-risk and low-risk patient pop-
`ulations with AAA, including phase I feasibility and phase II clinical trials. The low-risk study included concurrent sur-
`gical controls.
`Results: In the phase I trial, deployment success was achieved in 92% (23/25 patients), and initial technical success was
`78% (18/23 implants without endoleak). The 30-day technical success rate was 96%, with six endoleaks that resolved
`spontaneously (without need for further intervention); and the 30-day mortality rate was 12% (3/25 patients). The
`phase II high-risk trial demonstrated a deployment success of 94% (119/127 patients) and an initial technical success of
`86% (102/119 implants). The 30-day technical success rate was 96%, and the 30-day mortality rate was 1.5% (2/127
`patients). The phase II low-risk trial included a first-generation and a second-generation Talent stent-graft. Deployment
`success rates were 97% and 99%, respectively, and technical success rates at 30 days were 97% and 96%, respectively. The
`30-day mortality rate was 2% in the phase II low-risk first-generation device trial, and the adverse-event rate was 20%.
`Corresponding figures for the second-generation device were 0% and 1.8%, respectively.
`Conclusion: The Talent stent-graft can be deployed successfully and achieves endovascular exclusion in a large proportion
`of patients with AAA. Morbidity and mortality rates are acceptable. One-year clinical results and the comparison with
`concurrent surgical control subjects remain to be evaluated. (J Vasc Surg 2001;33:S146-9.)
`
`The Talent stent-graft (Medtronic World Medical,
`Sunrise, Fla) is an endovascular device that is undergoing
`clinical investigation to test its efficacy in the treatment of
`thoracic and abdominal aortic aneurysms (AAAs).
`Approximately 10,000 Talent stent-graft implantations
`have been performed worldwide since December 1995.
`Several studies have been conducted after US Food
`and Drug Administration approval of the investigational
`device exemption in April 1997.1 In this preliminary
`report, we present the technical and 30-day results
`obtained in the US phase I and phase II AAA trials. One-
`year clinical results and comparison with concurrent surgi-
`cal controls from Phase II will be the subject of a
`subsequent report.
`
`From the Center for Vascular Intervention, Division of Vascular Surgery,
`Union Memorial Hospital/MedStar Health,a and the Division of
`Vascular Surgery, Hospital of the University of Pennsylvania.b
`Competition of interest: FJC is a paid consultant and receives funding for
`a research assistant from Medtronic World Medical.
`Reprint requests: Frank J. Criado, MD, 3333 North Calvert St, Suite 570,
`Baltimore, MD 21218.
`Copyright © 2001 by The Society for Vascular Surgery and The American
`Association for Vascular Surgery, a Chapter of the International Society
`for Cardiovascular Surgery.
`0741-5214/2001/$35.00 + 0 24/0/111677
`doi:10.1067/mva.2001.111677
`
`S146
`
`METHODS
`Endovascular stent-graft device. The Talent device
`is a self-expanding, modular stent-graft system composed
`of serpentine-shaped nitinol stents inlaid in woven poly-
`ester fabric (Fig 1). The stents are spaced along a full-
`length nitinol spine. The latter provides longitudinal
`(column) strength to a graft that is otherwise flexible to
`accommodate aorto-iliac angulations. The delivery system
`is composed of a coaxial sheath with an internal pusher
`rod and a compliant polyurethane balloon that is sequen-
`tially inflated to maximize apposition of the graft to the
`vessel wall target zones and to ensure full expansion of the
`device along its length. The basic components of the
`Talent AAA system are a bifurcated main section and a
`contralateral iliac limb. Available configurations include
`the Free-Flo graft with a 15-mm long uncovered stent at
`the proximal end to allow transrenal or suprarenal fixa-
`tion. Additional modular components include aortic cuffs
`and iliac extensions. The manufacturer offers customiza-
`tion in a variety of configurations and sizes (length and
`diameters).2 Diameter ranges are 16 to 36 mm for the
`aortic section and 8 to 22 mm for the iliac limbs.
`Clinical studies. Several studies have assessed the
`safety and efficacy of the Talent stent-graft in the treat-
`ment of AAA. The clinical evaluation study designs
`
`MEDTRONIC 1137
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`JOURNAL OF VASCULAR SURGERY
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`Criado et al S147
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`Table I. Summary of deployment, technical success, clinically adverse events, and mortality rates associated with the
`four arms of the Talent stent-graft trials for the treatment of AAA
`
`Clinical
`trial
`
`Deployment success
`rate (%)
`
`Technical success
`rate (%)
`
`Technical success
`rate
`
`30-Day (%)
`Adverse event
`rate
`
`Mortality
`rate
`
`Phase I high-risk feasibility
`Phase II high-risk
`Phase II low-risk (first-generation)
`Phase II low-risk (second-generation)
`
`92 (23/25)
`94 (119/127)
`97 (147/151)
`99 (167/168)
`
`78 (18/23)
`86 (102/119)
`88 (130/147)
`80 (133/167)
`
`96 (22/23)
`96 (114/119)
`97 (138/142)
`96 (68/71)
`
`40 (10/25)
`14.9 (19/127)
`20 (29/142)
`4 (3/71)
`
`12 (3/25)
`1.5 (2/127)
`2 (3/142)
`0
`
`included a phase I feasibility study involving six investiga-
`tional sites to demonstrate device and procedure safety
`before the expansion to multiple phase II controlled studies
`(in adherence to the US Food and Drug Administration
`guidelines) that involve several designs. The phase II stud-
`ies were conducted at 17 investigational sites. In one arm
`(low-risk trial), endovascular repair was compared with stan-
`dard operation as performed concurrently on surgical con-
`trol patients who were selected on the basis of unsuitable
`anatomy for endovascular repair or a refusal to undergo the
`stent-graft procedure. (The control data will appear in a
`subsequent report.)
`Endovascular stent-graft procedure. The Talent
`stent-graft AAA procedure was performed with general,
`epidural/spinal, or local anesthesia and involved bilateral
`groin incisions for exposure of the common femoral arter-
`ies. The use of adjunctive brachial artery catheterization
`was according to individual discretion. Imaging from a
`fixed or mobile fluoroscopy system and power-injector
`angiography were used to guide the placement of the
`stent-graft. Aorto-uniiliac implantations required con-
`tralateral iliac artery exclusion by surgical ligation, coil
`embolization (or a combination of the two), and crossover
`femorofemoral bypass grafting.
`Definitions and criteria. Risk factor stratification
`adhered to The Society for Vascular Surgery/International
`Society for Cardiovascular Surgery guidelines,3,4 with risk-
`level scores of 0, 1, or 2 being deemed as “low risk” and 3
`as “high risk.” Deployment success was defined as the ability
`to deliver the stent-graft device into position as intended.
`Technical success was defined as successful deployment with-
`out endoleak. Adverse events were defined as any compli-
`cation that required additional procedures and/or
`prolonged hospitalization (ie, arterial rupture or dissec-
`tion, renal dysfunction, lower extremity ischemia, signifi-
`cant cardiac or respiratory complications, and conversion
`to surgery).
`Follow-up evaluation. Patients underwent abdomi-
`nal radiography and contrast/noncontrast spiral com-
`puted tomography scans before discharge to evaluate
`device placement, patency of the graft, aneurysm size,
`renal artery patency, and presence or absence of endoleak.
`These studies were reviewed locally at each site and at an
`
`independent core laboratory facility. After discharge, the
`patients were evaluated at 1 month, 6 months, 1 year, and
`yearly thereafter.
`
`RESULTS
`Phase I high-risk. In the phase I feasibility trial, 25
`patients with infrarenal AAA were enrolled at six centers.
`The average aneurysm size was 61 ± 15 mm, with 24 male
`and one female patients. Nearly one half of the patients (12
`patients) had severe coronary artery disease; five patients had
`a ventricular ejection fraction of less than 30%. Deployment
`success was achieved in 23 of 25 patients (92%). In two
`patients, deployment failed because of delivery/access diffi-
`culties. These two cases were immediately converted to open
`aneurysm repair; one of the patients died in the postopera-
`tive period. The overall 30-day mortality rate was 12% (3/25
`patients). The technical success rate at initial deployment was
`78%, with seven of 23 implanted showing evidence of an
`endoleak at the completion of the stent-graft procedure.
`Some of these endoleaks were retrospectively attributed to
`“contrast blush” through the graft. At 30 days, only one
`patient had a persistent endoleak on computed tomography
`scan, for a 96% 30-day technical success rate. The other
`endoleaks closed spontaneously. Adverse events were identi-
`fied in 10 patients (40%) and included limb ischemia,
`myocardial infarction, congestive heart failure, renal failure,
`and groin wound infections (Table I).
`Phase II high-risk. One hundred twenty-seven
`patients at 17 centers qualified for the phase II high-risk
`trial that used either the bifurcated Talent stent-graft
`design or the aorto-uniiliac configuration with a femoro-
`femoral bypass. The mean aneurysm diameter was 57 ± 10
`mm. All patients were found to be high risk, with 15% of
`the patients having an ejection fraction of less than 20, and
`10% of the patients being over the age of 90 years. Ninety-
`nine patients received the bifurcated device; 28 patients
`received an aorto-uniiliac stent-graft. Deployment success
`was achieved in 94% of the patients (119/127 patients),
`with deployment failure in eight patients. Initial technical
`success (absence of endoleak) was documented in 102
`patients (86%). Success at 30 days was found to be 96%
`(114/119 patients). The adverse-event rate was 14.9%
`(19/127 patients), the most common complications
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`

`S148 Criado et al
`
`JOURNAL OF VASCULAR SURGERY
`February 2001
`
`exemption. One hundred fifty-one patients were selected
`under the low-risk inclusion criteria. Successful deploy-
`ment was realized in 147 patients (97%), with initial tech-
`nical success in 130 patients (88%). Ninety-seven percent
`of patients (138/142 evaluated) were free of endoleaks at
`30 days. Adverse events were seen in 29 of 142 patients
`(20%) and included arterial dissection or rupture in seven
`patients, renal failure in six patients, ischemia of the lower
`extremities in two patients, myocardial infarction in five
`patients, respiratory complications in three patients,
`arrhythmias in three patients, and conversion to open
`surgery in four patients. The 30-day mortality rate was 2%
`(three patients). Causes of death included respiratory fail-
`ure in two patients and myocardial infarction in one
`patient (Table I).
`Phase II low-risk (second-generation device). The
`original Talent stent-graft and delivery system evolved into
`the low-profile system and was evaluated in a separate clin-
`ical study. Low-risk criteria were observed in 168 patients
`who were enrolled in this arm of the trial. A concurrent
`surgical control population was also evaluated, the results
`of which will be reported subsequently with the 1-year
`data. Deployment was successful in 99% of the patients
`(167/168 patients), and initial technical success was
`achieved in 80% of the patients (133 patients). Thirty-day
`success (no endoleak) was seen in 68 of 71 patients (96%)
`who were available for evaluation. Procedure-related com-
`plications included one patient with a thrombosed stent-
`graft limb, another patient with respiratory failure, and an
`additional patient with postoperative paraplegia from
`spinal cord ischemia. No patients died during the proce-
`dure or the initial 30-day follow-up (zero mortality rate;
`Table I).
`
`DISCUSSION
`Despite ongoing doubt5 and recent concerns sur-
`rounding clinical efficacy and durability,6 stent-graft repair
`of AAA is by far the most exciting development in vascu-
`lar surgery in many years. All clinical investigators recog-
`nize the somewhat “unfinished” nature of endoluminal
`graft technology that, by all accounts, is still in its
`“infancy.” Future developments will likely address the
`major unresolved issues, mainly deliverability to the aortic
`lumen, reliable fixation in challenging proximal necks and,
`foremost, the ability to adjust to evolving morphologic
`changes (as the excluded aneurysm shrinks) without dis-
`connections, dislocations, or migration. The occurrence of
`endoleaks and the potential for late aneurysm rupture
`after stent-graft repair continue to be causes for concern.
`The Talent stent-graft has proved versatile in the treat-
`ment of a wide range of aortic aneurysms of various mor-
`phologic conditions. It is the only currently available
`commercially produced device that is capable of addressing
`AAA necks larger than 28 mm in diameter.7 Customization
`
`Fig 1. The modular bifurcated Talent aortic stent-graft. Note the
`“bare spring” proximal nitinol stent configuration for trans- and
`suprarenal fixation.
`
`being renal failure, congestive heart failure, and graft limb
`thrombosis. Two of the 127 patients (1.5%) died; one
`patient had overwhelming disseminated intravascular
`coagulopathy, and the other patient experienced a fatal
`myocardial infarction on day 30 (Table I).
`Phase II low-risk (first-generation device). This
`phase II trial used the first generation Talent stent-graft
`and delivery system, both of which were later modified
`and resubmitted under an additional investigational device
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`JOURNAL OF VASCULAR SURGERY
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`
`Criado et al S149
`
`capabilities (as offered by the manufacturer) have provided
`a niche for the Talent technology and made it distinct in
`the stent-graft field. Interestingly, such characteristics (and
`the fact that initial investigational device exemption
`approval in the United States was for high-risk patients
`only) have resulted in the application of the Talent device
`in a disproportionately large percentage of surgically unfit
`patients. Morbidity and mortality rates in some of the stud-
`ies clearly reflect its use in such anatomically and medically
`disadvantaged patient population. It would be fair to state
`that the Talent stent-graft is the one device that many, if
`not most, investigators around the world resort to for large
`aortic necks and “difficult AAA anatomy.”
`The data reflect the technical performance of the
`device and 30-day clinical outcome obtained at 17 investi-
`gational centers in the United States. The Talent aortic
`stent-graft appears to be an effective device for the
`endovascular exclusion of AAA. The thinner-graft low-pro-
`file system (Talent low profile system) has been a particu-
`larly welcome evolution, which has resulted in a decrease of
`procedure-related adverse events from 20% to just under
`5%. The 1-year clinical results (currently undergoing audit-
`ing and tabulation) and a comparison with concurrent sur-
`gical controls will be published at a later time.
`
`The principal investigators at the 17 investigational
`sites for the US Talent AAA trials: Frank J. Criado, MD;
`
`Gary Becker, MD; Barry T. Katzen, MD; Frank J. Veith,
`MD; Renan Uflacker, MD; Edward B. Diethrich, MD;
`Michael Belkin, MD; Michael Hallisey, MD; Michael
`Khoury, MD; Paul Bove, MD; Alexander Balko, MD;
`Ronald M. Fairman, MD; Richard Green, MD; Robert
`Allen, MD; Rodney A. White, MD; Patricia Cole, MD;
`Roy K. Greenberg, MD; Richard Heuser, MD; and
`Thomas J. Fogarty, MD.
`
`REFERENCES
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`stent-graft system: report of the phase I USA trial, and summary of
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`2. Criado FJ, Wilson EP, Martin JA, et al. Custom manufacturing of aor-
`tic stent-grafts to expand applicability of endovascular repair: In:
`Greenhalgh RM, Powell JT, Mitchell AW, editors. Vascular and
`endovascular opportunities. London: Saunders; 2000. p. 287-96.
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`gold standard. J Endovasc Surg 1997;4:232-41.
`4. Hollier LH, Taylor LM, Ochsner J, et al. Recommended indications
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`rent status. Cardiovasc Surg 1999;7:684-91.
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`cular repair using the AneuRx stent graft. J Vasc Surg 2000;31:960-
`70.
`7. Criado FJ, Abul-Khoudoud O, Wellons E, et al. The Talent abdomi-
`nal aortic aneurysm stent-graft: technical approaches and results of
`aneurysm exclusion. In: Greenhalgh RM, editor. The durability of vas-
`cular and endovascular surgery. London: Saunders; 1999. p. 433-48.
`
`Submitted Jun 21, 2000; accepted Aug 18, 2000.
`
`