Balloon-expandable Stent Research Articles

BALLOON-EXPANDABLE STENTS EXPANSION IN TAPERED VESSELS AND THEIR INTERACTIONS

In-stent restenosis (ISR) after stent implantation, especially in tapered vessels, remains an obstacle in the long-term benefits of stenting. In the present study, a finite element method (FEM) was employed to investigate the expansion process of balloon-expandable stents in tapered vessels (the TV model) and their interactions. For comparison, a numerical model of the same stent deployment in a straight vessel was also investigated. Results showed that in the TV model, the peak tissue stresses took place at the distal end of the tapered vessel. The node displacements of the stent's proximal and distal ends remained consistent before the stent contacted the tapered vessel, while the proximal end was larger than the distal end after the stent contacted the tapered vessel. The regions of maximum stresses in the stent after expansion were concentrated in the corners of the diamond cells of the stent's proximal end. The investigation provided some interpretations of the clinical observations in tapered vessels and also provided stent design proposals for tapered vessels. The FEM quantified the mechanical properties of stents in tapered vessels, and can help clinicians select appropriate stents, assist designers in pretests and create new stents made especially for tapered vessels.

Abstract 11884: Successful Preclinical Study of Microporous Covered Stents for Intracranial Aneurysms

Introduction: Treatment of large or giant cerebral aneurysms with broad neck is extremely difficult or carries high risks, even with clinical available surgical method or endovascular one using coils with the assistance of bare stents. We are developing microporous covered stents (Goodman, Japan) for the treatment of intracranial aneurysms. In this study, as a preclinical study, their performances were evaluated in three different in vivo animal models under reliability assurance system (RAS). Methods and Results: The covered stents were prepared using specially designed flexible balloon-expandable stents (CoCr; diameter; 3.5~5.0 mm, length; 16~28 mm) by dip-coating to cover their strut completely with polyurethane membrane (thickness; 20 μm) followed by laser-based microprocessing (pore size; 100 μm, opening ratio; ~30%). All animal experiments were performed under RAS. 1) In canine curved vessel model (5 mm in diameter), all stents mounted on the derivery catheter could smoothly pass the tortuous vessel with little arterial damage (n=10). 2) In canine sidewall aneurysm model, all post-immediate run showed disappearance of the aneurysm (over 7 mm in size, 4 mm in wide), and histological examination at 3 months revealed complete endothelialization at the aneurysmal neck and entirely organized aneurysm (n=20). 3) In rabbit aortic model (3 mm in diameter), just after placing a single stent lumbar arteries (less than 1 mm) were patent with good run-off. Even after placing the second stent in an overlapped fashion lumbar arteries are still patent. After 3 months, both the parent artery and branching lumbar arteries are patent in all cases (n=15). The safety of the covering material was guaranteed at over 2 years (n=10). Conclusions: Excellent embolization performance was confirmed in all cases even at the large and wide-necked aneurysms on the tortuous vessels with high reliability. Based on the obtained perfect preclinical results we are planning the first in human study of the covered stents for intracranial aneurysms in 2015.

Stenting for curved lesions using a novel curved balloon: Preliminary experimental study

BackgroundStenting may be a compelling approach to dilating curved lesions in congenital heart diseases. However, balloon-expandable stents, which are commonly used for congenital heart diseases, are usually deployed in a straight orientation. In this study, we evaluated the effect of stenting with a novel curved balloon considered to provide better conformability to the curved-angled lesion. Materials and methodsIn vitro experiments: A Palmaz Genesis® stent (Johnson & Johnson, Cordis Co, Bridgewater, NJ, USA) mounted on the Goku® curve (Tokai Medical Co. Nagoya, Japan) was dilated in vitro to observe directly the behavior of the stent and balloon assembly during expansion. Animal experiment: A short Express® Vascular SD (Boston Scientific Co, Marlborough, MA, USA) stent and a long Express® Vascular LD stent (Boston Scientific) mounted on the curved balloon were deployed in the curved vessel of a pig to observe the effect of stenting in vivo. ResultsIn vitro experiments: Although the stent was dilated in a curved fashion, stent and balloon assembly also rotated conjointly during expansion of its curved portion. Animal experimentIn the primary stenting of the short stent, the stent was dilated with rotation of the curved portion. The excised stent conformed to the curved vessel. As the long stent could not be negotiated across the mid-portion with the balloon in expansion when it started curving, the mid-portion of the stent failed to expand fully. Furthermore, the balloon, which became entangled with the stent strut, could not be retrieved even after complete deflation. ConclusionThis novel curved balloon catheter might be used for implantation of the short stent in a curved lesion; however, it should not be used for primary stenting of the long stent. Post-dilation to conform the stent to the angled vessel would be safer than primary stenting irrespective of stent length.

A registry on distal popliteal and infrapopliteal revascularization with coronary drug-eluting stents.

Endovascular therapy for popliteal and infrapopliteal artery disease in patients with critical limb ischemia (CLI) remains challenging, given the high risk of adverse events. Favorable results for coronary balloon-expandable drug-eluting stents (DESs) in this arterial district have been reported in selected studies, but uncertainty persists on their risk-benefit balance in real-world patients. We, thus, sought to appraise our outcomes with DES implantation for distal popliteal or infrapopliteal lesions. Our institutional databases were retrospectively queried to identify patients undergoing DES implantation for distal popliteal or infrapopliteal artery disease. Baseline, lesion, procedural, and outcome data were systematically collected. A total of 25 patients were treated with coronary DES, 12 (48.0%) for distal popliteal and 13 (52.0%) for infrapopliteal lesions. Four (16.0%) patients received two stents, whereas the others only one. Breakdown of DES was as follows: biolimus-eluting, everolimus-eluting, paclitaxel-eluting, and sirolimus-eluting stents in, respectively, two (8.0%), one (4.0%), one (4.0%), and 21 (84.0%), with an average stent length of 33.6 ± 13.1 mm. Improvement in Fontaine stage was achieved in 23 (92.0%) patients at 1 month and in 22 (88.0%) patients at long-term (28.8 ± 20.6 months). In this highly selected case series, no repeat revascularizations or unplanned amputations were recorded, whereas two (8.0%) patients died, the first 15.5 months and the second 19.5 months after the procedure. Implantation of coronary balloon-expandable DES appears feasible, safe, and effective in selected patients with focal lesions in the distal popliteal and infrapopliteal arteries.

Intracranial stents past, present and the future trend: stents made with nano-particle or nanocomposite biomaterials.

Stroke or cerebral vascular accidents are among the leading causes of death in the world. With the availability of Digital Subtraction Angiography, transluminal angioplasty has become feasible in many situations and the role of intracranial stents is becoming ever more important in the management of cerebral vascular diseases. In current review, we outline the chronological development of various stents namely; balloon expandable stent, self-expandable open cell stent, self-expandable close cell stent and the flow diverting stent. Further we discuss their advantages and limitations in terms of stent migration, thromboemboli, damage to vessels during procedure, in-stent stenosis and hyper-perfusion damage. We also discuss the importance of in-situ endothelialization, controlled expandability and hemodynamic manipulation in stent design. Further, we summarized the role and need for further development in the areas of bio-compatible materials, endothelial progenitor cell capture technique, bio-functionalized-magnetic-nano-particles and nanotechnology which are significant in intracranial stent development.

Retraction notice

Background: Implantation of a stent into a stenotic artery is almost a purely mechanical process. The success of this process is largely correlated to the arterial and plaque component mechanical properties. The mechanical properties of animals’ arteries, so far, have been typically employed in stent simulation studies. However, it has been found that the mechanical properties of animals’ arteries may not have similar mechanical properties to that of human coronary arteries and, consequently, may invoke a substantial underestimation of stresses induced on the arterial and plaque walls. Methods: In this study, a non-linear, finite element simulation was carried out to evaluate the stresses on a realistic stenotic human coronary artery in the presence of different plaque types (calcified, cellular and hypocellular) to determine the most vulnerable plaque during the implantation of a balloon-expandable stent. Results: A significant difference was detected for the stresses induced on plaque and stent walls for different plaque types, but not when computing maximum stress on the arterial wall. The highest von Mises stresses were observed on the stent with calcified plaque (200.8 MPa). Despite the stress on a stiffer calcified plaque wall being in the fracture level (2.11 MPa), the cellular and hypocellular plaques can bear more stress on their walls. Conclusions: These findings may have implications, not only for determining the most vulnerable plaque inside a stenotic artery, but also for intervention and surgeries, i.e., angioplasty and stenting.

Polytetrafluoroethylene Covered Stent Placement for Focal Occlusive Disease of the Infrarenal Aorta

Arterial insufficiency is rarely caused by isolated infrarenal aortic occlusive lesions. Endovascular treatment options include plain balloon angioplasty and bare metal stent placement. In this study the feasibility and efficacy of polytetrafluoroethylene (PTFE) covered balloon expandable stents were evaluated. Consecutive patients from two centers were prospectively collected in a database and retrospectively analyzed. Results were evaluated by clinical examination, ankle-brachial indices (ABI), duplex ultrasound, and plain abdominal radiography. Thirty-six consecutive patients were treated between November 2008 and June 2013. Indication for treatment was Rutherford 3 (n = 29), 4 (n = 3), and 5 (n = 4). Technical success was always achieved and there were no distal embolizations or vessel wall ruptures. The median follow-up was 22 months (range 0–60). All patients improved clinically and the ABI increased significantly from 0.73 ± 0.18 to 1.01 ± 0.14 (p < .01). One patent covered stent was removed surgically because of infection. Primary patency rates were 100% at 1 and 2 years without stent fractures. The use of PTFE covered stents for the treatment of isolated infrarenal aortic occlusive disease is safe and very effective. Patency rates are excellent and complications including distal embolization and vessel wall rupture are extremely rare.

Nellix® endovascular aneurysm sealing (EVAS) - a new technology for endovascular management of infrarenal aortic aneurysms

Recently used endografts for envascular aneurysm repair (EVAR) exclude the pathology by fixation at both the proximal and distal landing zone. Due to endoleaks and migration EVAR is associated with a relevant rate of secondary interventions. The Nellix® system (Endologix Inc., CA, USA) was developed to seal the complete aneurysm using a polymer filling, therefore stabilising endograft-position and reducing the rate of endoleaks and reinterventions. The present contribution introduces the method, describes the technique of implantation and presents the first clinical results. Material und Methods: The Nellix system consists of two balloon-expandable stent grafts made of a cobalt-chromium composition, surrounded with ePTFE and the so-called endobags. During the implantation each endobag is filled with a non-biodegradable polymer, sealing the aneurysm lumina including the proximal and distal landing zone. Hence, lumbar arteries will be sealed to reduce the probability of a type II endoleak. Longterm durability as well as the structural integrity of the Nellix system has been proven over 4 years in sheep experiments. The technical success in a multicentre, prospective registry was 94% without the appearance of severe adverse events (migration, occlusion, secondary endoleak). EVAS is a new and different concept of endovascular AAA repair. Recent clinical data of the Nellix system are promising showing a high technical success rate while the need for secondary intervention is low. Further studies in larger cohorts are needed.

English

INTRODUCTION Coeliac artery dissection (CAD) is usually secondary to aortic dissection, and it is detected more often after multislice computed tomography angiography (CTA) is performed in the diagnosis of abdominal pain. We report a case of secondary coeliac artery dissection treated with three overlapping balloon-expandable stents, and discuss the techniques of endovascular

Polytetrafluoroethylene Covered Stent Placement for Focal Occlusive Disease of the Infrarenal Aorta

Arterial insufficiency is rarely caused by isolated infrarenal aortic occlusive lesions. Endovascular treatment options include plain balloon angioplasty and bare metal stent placement. In this study the feasibility and efficacy of polytetrafluoroethylene (PTFE) covered balloon expandable stents were evaluated. Consecutive patients from two centers were prospectively collected in a database and retrospectively analyzed. Results were evaluated by clinical examination, ankle-brachial indices (ABI), duplex ultrasound, and plain abdominal radiography. Thirty-six consecutive patients were treated between November 2008 and June 2013. Indication for treatment was Rutherford 3 (n = 29), 4 (n = 3), and 5 (n = 4). Technical success was always achieved and there were no distal embolizations or vessel wall ruptures. The median follow-up was 22 months (range 0-60). All patients improved clinically and the ABI increased significantly from 0.73 ± 0.18 to 1.01 ± 0.14 (p < .01). One patent covered stent was removed surgically because of infection. Primary patency rates were 100% at 1 and 2 years without stent fractures. The use of PTFE covered stents for the treatment of isolated infrarenal aortic occlusive disease is safe and very effective. Patency rates are excellent and complications including distal embolization and vessel wall rupture are extremely rare.

Results of the United States multicenter prospective study evaluating the Zenith fenestrated endovascular graft for treatment of juxtarenal abdominal aortic aneurysms

This study reports the results of a prospective, multicenter trial designed to evaluate the safety and effectiveness of the Zenith fenestrated endovascular graft (Cook Medical, Bloomington, Ind) for treatment of juxtarenal abdominal aortic aneurysms (AAAs). Sixty-seven patients with juxtarenal AAAs were prospectively enrolled in 14 centers in the United States from 2005 to 2012. Custom-made fenestrated stent grafts were designed with one to three fenestrations on the basis of analysis of computed tomography data sets. Renal alignment was performed with balloon-expandable stents. Follow-up included clinical examination, laboratory studies, mesenteric-renal duplex ultrasound, abdominal radiography, and computed tomography imaging at hospital discharge and at 1 month, 6 months, and 12 months and yearly thereafter up to 5 years. There were 54 male and 13 female patients with a mean age of 74 ± 8 years enrolled. Mean aneurysm diameter was 60 ± 10 mm. A total of 178 visceral arteries required incorporation with small fenestrations in 118, scallops in 51, and large fenestrations in nine. Of these, all 118 small fenestrations (100%), eight of the scallops (16%), and one of the large fenestrations (11%) were aligned by stents. Technical success was 100%. There was one postoperative death within 30 days (1.5%). Mean length of hospital stay was 3.3 ± 2.1 days. No aneurysm ruptures or conversions were noted during a mean follow-up of 37 ± 17 months (range, 3-65 months). Two patients (3%) had migration ≥ 10 mm with no endoleak, both due to cranial progression of aortic disease. Of a total of 129 renal arteries targeted by a fenestration, there were four (3%) renal artery occlusions and 12 (9%) stenoses. Fifteen patients (22%) required secondary interventions for renal artery stenosis/occlusion in 11 patients, type II endoleak in three patients, and type I endoleak in one patient. At 5 years, patient survival was 91% ± 4%, and freedom from major adverse events was 79% ± 6%; primary and secondary patency of targeted renal arteries was 81% ± 5% and 97% ± 2%, freedom from renal function deterioration was 91% ± 5%, and freedom from secondary interventions was 63% ± 9%. This prospective study demonstrates that endovascular repair of juxtarenal AAAs with the Zenith fenestrated AAA stent graft is safe and effective. Mortality and morbidity are low in properly selected patients treated in centers with experience in these procedures.

TCT-447 Usefulness of Polyzene-F nanocoated stent to facilitate reendothelialization and reduce thrombus formation. In vivo results of stented rabbit iliac arteries

The CeloNova COBRA PzF™ Coronary Stent is a new stent design, balloon expandable cobalt chromium alloy coronary stent that is pre-mounted on a custom rapid exchange balloon delivery catheter. The alloy stent is surface treated with a nano-layer Polyzene®-F (PzF). Polyzene-F is an inorganic

Concomitant use of drug-eluting balloon-expandable and self-expandable stents: An approach to avoid surgical revascularization

Concomitant use of drug-eluting balloon-expandable and self-expandable stents: An approach to avoid surgical revascularization

Angiotensin II type 1 receptor blockers suppress neointimal hyperplasia after stent implantation in carotid arteries of hypercholesterolemic rabbits

Objectives:The purpose of this study was to examine whether oral administration of an angiotensin II type 1 receptor blocker (ARB) inhibited in-stent neointimal hyperplasia in carotid arteries of hypercholesterolemic rabbits.Methods:Eleven male New Zealand white rabbits were subjected to endothelial injuries of the right common carotid arteries using a balloon catheter and then received chow containing 1% cholesterol for 6 weeks. A balloon-expandable stainless steel stent was subsequently inserted at the injured sites of the arteries. After stenting, five rabbits were randomly treated with an oral ARB, candesartan cilexetil (5 mg/kg per day orally), while the remaining six rabbits acted as untreated controls. Four weeks after the implantation, the rabbits were killed, followed by collection of the arteries including the stents. After careful removal of the stents, tissue sections were prepared and analyzed by morphometric and immunohistochemical methods.Results:The mean thickness of the neointima was 53·6±17·0 μm in the ARB-treated group, which was significantly reduced compared to 95·9±16·7 μm in the control group (P = 0·0012). Immunohistochemistry showed a decrease in accumulation of macrophages and tenascin-C expression in the arterial wall in the ARB-treated animals.Discussion:This study suggested that systemic administration of an ARB suppressed neointimal hyperplasia in the carotid artery following stent implantation by the anti-inflammatory effects, although the animal cohort tested was rather small. This finding implies that ARBs may be useful and practical agents for protection against in-stent restenosis in humans, and warrants further basic and clinical studies.

Three-year hemodynamic performance, left ventricular mass regression, and prosthetic-patient mismatch after rapid deployment aortic valve replacement in 287 patients

Superior aortic valve hemodynamic performance can accelerate left ventricular mass regression and enhance survival and functional status after surgical aortic valve replacement. This can be achieved by rapid deployment aortic valve replacement using a subannular balloon-expandable stent frame, which functionally widens and reshapes the left ventricular outflow tract, to ensure a larger effective orifice area compared with conventional surgical valves. We report the intermediate-term follow-up data from a large series of patients enrolled in the Surgical Treatment of Aortic Stenosis With a Next Generation Surgical Aortic Valve (TRITON) trial. In a prospective, multicenter (6 European hospitals), single-arm study, 287 patients with aortic stenosis underwent rapid deployment aortic valve replacement using a stented trileaflet bovine pericardial bioprosthesis. Core laboratory echocardiography was performed at baseline, discharge, and 3 months, 1 year, and 3 years after rapid deployment aortic valve replacement. The mean patient age was 75.7 ± 6.7 years (range, 45-93; 49.1% women). The mean aortic valve gradient significantly decreased from discharge to 3 years of follow-up. The mean effective orifice area remained stable from discharge to 3 years. At 1 year, the left ventricular mass index had decreased by 14% (P < .0001) and at 3 years by 16% (P < .0001) compared with at discharge. The prevalence of severe patient-prosthesis mismatch was 3% at discharge and remained stable during the follow-up period. In a large series of elderly patients with symptomatic severe aortic stenosis, rapid deployment aortic valve replacement using a subannular balloon-expandable stent frame demonstrated excellent hemodynamic performance and significant left ventricular mass regression. With continued follow-up, future studies will establish whether these favorable structural changes correlate with improvement in long-term survival and functional status.

APPOSITION V: STENTYS coronary stent system clinical trial in subjects with ST-segment elevation myocardial infarction—Rationale and design

Primary percutaneous coronary intervention (PCI) has considerably improved clinical outcomes in patients with ST-segment elevation myocardial infarction (STEMI) when compared with thrombolytic therapy. Prognosis after primary PCI might be further improved by decreasing stent-related complications such as stent thrombosis. The STENTYS self-apposing stent has been shown to be superior compared with balloon-expandable stents with regard to stent apposition. The current prospective randomized trial was designed to evaluate whether the superior stent apposition of the STENTYS stent results in clinical outcomes that are at least noninferior to a conventional balloon-expandable stent. The APPOSITION V is a prospective, multicenter, international, single-blinded, randomized controlled trial in STEMI patients. Randomization will be performed in a 2:1 ratio between the self-apposing nitinol bare-metal STENTYS stent and the balloon-expandable bare-metal MULTI-LINK. The primary end point is defined as target vessel failure, which is a composite of cardiac death, target vessel-related recurrent myocardial infarction, or clinically driven target vessel revascularization, at 1-year follow-up. Baseline intravascular ultrasound and optical coherence tomography (OCT) substudies will be performed in 212 and 60 subjects, respectively, and a repeat angiography at 12 to 13 months will be performed in 105 subjects, including intravascular ultrasound and OCT (in the 60 OCT patients). This study is registered on ClinicalTrials.gov with number NCT01732341. APPOSITION V will be the first randomized trial powered on clinical end points that directly compares the STENTYS self-apposing stent with a conventional balloon-expandable stent in patients presenting with STEMI undergoing primary PCI.

A finite element study of balloon expandable stent for plaque and arterial wall vulnerability assessment

The stresses induced within plaque tissues and arterial layers during stent expansion inside an atherosclerotic artery can be exceeded from the yield stresses of those tissues and, consequently, lead to plaque or arterial layer rupture. The distribution and magnitude of the stresses in each component involved in stenting might be clearly different for different plaque types and different arterial layers. In this study, a nonlinear finite element simulation was employed to investigate the effect of plaque composition (calcified, cellular, and hypocellular) on the stresses induced in the arterial layers (intima, media, and adventitia) during implantation of a balloon expandable coronary stent into a stenosed artery. The atherosclerotic artery was assumed to consist of a plaque and normal/healthy arterial tissues on its outer side. The results indicated a significant influence of plaque types on the maximum stresses induced within the plaque wall and arterial layers during stenting but not when computing maximum stress on the stent. The stress on the stiffest calcified plaque wall was in the fracture level (2.38 MPa), whereas cellular and hypocellular plaques remain stable owing to less stress on their walls. Regardless of plaque types, the highest von Mises stresses were observed on the stiffest intima layer, whereas the lowest stresses were seen to be located in less stiff media layer. The computed stresses on the intima layer were found to be high enough to initiate a rupture in this stiff layer. These findings suggest a higher risk of arterial vascular injury for the intima layer, while a lower risk of arterial injury for the media and adventitia layers.

Computational fluid dynamics analysis of balloon-expandable coronary stents: Influence of stent and vessel deformation

In many computational fluid dynamics (CFD) studies of stented vessel haemodynamics, the geometry of the stented vessel is described using non-deformed (NDF) geometrical models. These NDF models neglect complex physical features, such as stent and vessel deformation, which may have a major impact on the haemodynamic environment in stented coronary arteries. In this study, CFD analyses were carried out to simulate pulsatile flow conditions in both NDF and realistically-deformed (RDF) models of three stented coronary arteries. While the NDF models were completely idealised, the RDF models were obtained from nonlinear structural analyses and accounted for both stent and vessel deformation. Following the completion of the CFD analyses, major differences were observed in the time-averaged wall shear stress (TAWSS), time-averaged wall shear stress gradient (TAWSSG) and oscillatory shear index (OSI) distributions predicted on the luminal surface of the artery for the NDF and RDF models. Specifically, the inclusion of stent and vessel deformation in the CFD analyses resulted in a 32%, 30% and 31% increase in the area-weighted mean TAWSS, a 3%, 7% and 16% increase in the area-weighted mean TAWSSG and a 21%, 13% and 21% decrease in the area-weighted mean OSI for Stents A, B and C, respectively. These results suggest that stent and vessel deformation are likely to have a major impact on the haemodynamic environment in stented coronary arteries. In light of this observation, it is recommended that these features are considered in future CFD studies of stented vessel haemodynamics.

A nonlinear finite element simulation of balloon expandable stent for assessment of plaque vulnerability inside a stenotic artery.

The stresses induced on plaque wall during stent implantation inside a stenotic artery are associated with plaque rupture. The stresses in the plaque-artery-stent structure appear to be distinctly different for different plaque types in terms of both distribution and magnitude. In this study, a nonlinear finite element simulation was executed to analyze the influence of plaque composition (calcified, cellular, and hypocellular) on plaque, artery layers (intima, media, and adventitia), and stent stresses during implantation of a balloon expandable coronary stent into a stenosed artery. The atherosclerotic artery was assumed to consist of a plaque and normal arterial tissues on its outer side. The results revealed a significant influence of plaque types on the maximum stresses induced within plaque wall and artery layers during stenting, but not when calculating maximum stress on stent. The stress on stiffer calcified plaque wall was in the fracture level (2.21 MPa), whereas cellular and hypocellular plaques play a protective role by displaying less stress on their wall. The highest von Mises stresses were observed on less stiff media layer. The findings of this study suggest a lower risk of arterial vascular injury for calcified plaque, while higher risk of plaque ruptures for cellular and hypocellular plaques.

L6. Five-Year Results of the United States Multicenter Prospective Study Evaluating the Zenith® Fenestrated Endovascular Graft for Treatment of Juxtarenal Abdominal Aortic Aneurysms

This study reports results of a prospective, multicenter trial designed to evaluate the safety and effectiveness of the Zenith® Fenestrated AAA Endovascular Graft (ZFEN, Cook Medical, Bloomington IN) for treatment of juxtarenal abdominal aortic aneurysms (AAAs). Sixty-seven patients with juxtarenal AAAs were prospectively enrolled in 14 U.S. centers (2005-2012). Custom-made fenestrated stent-grafts were designed with up to three fenestrations based on analysis of computed tomography (CT) datasets. Renal alignment was performed using balloon-expandable stents. Follow up included clinical examination, laboratory studies, duplex ultrasound, abdominal X-rays and CT imaging at hospital discharge, 1, 6, 12 months, and yearly thereafter up to 5 years. here were 54 male and 13 female patients with a mean age of 74±8 years old enrolled. Mean aneurysm diameter was 60 ± 10 mm. A total of 178 visceral arteries required incorporation with small fenestrations in 118, scallops in 51 and large fenestrations in 9. Of these, all 118 small fenestrations (100%), 8 of the scallops (16%), and 1 of the large fenestrations (11%) were aligned by stents. Technical success was 100%. There was one postoperative death within 30 days (1.5%). Mean length of hospital stay was 3 ± 2 days. There were no type I or III endoleaks, aneurysm ruptures or conversions noted during a mean follow up of 37 ± 17 months (3-65 months). Two patients (3%) had migration >5 mm with no endoleak due to cranial progression of aortic disease. Of a total of 129 renal arteries targeted by a fenestration, there were 4 (3%) renal artery occlusions and 10 (8%) stenoses. Fifteen patients (22%) required secondary interventions for renal artery stenosis/occlusion in 11 patients, type II endoleak in three and indeterminate endoleak in one. At 5 years, patient survival was 91% ± 4%, freedom from major adverse events was 79% ± 6%, primary and secondary patency of targeted renal arteries was 81±5% and 97% ± 2%, freedom from renal function deterioration was 91±5%, and freedom from secondary interventions was 63% ± 9%. This prospective study demonstrates that endovascular repair of juxtarenal AAAs using ZFEN is safe, effective and durable. Mortality and morbidity are low in properly selected patients treated in centers with experience in these procedures.