Non-compliant Balloon Research Articles

Successful use of bioresorbable vascular scaffold in in-stent restenosis previously exposed to vascular brachytherapy

A 71 year-old lady with a history of hypercholesterolemia and coronary artery disease presented with stable effort angina for 6 months. She first presented with stable effort angina 16 years ago with percutaneous coronary intervention to proximal right coronary artery (RCA) with a 2.5 × 32 mm bare metal stent. The patient subsequently experienced angina again after one year, and coronary angiogram revealed RCA diffuse in-stent restenosis (ISR). She was then treated with laser angioplasty as debulking, followed by balloon angioplasty with a 3.0 mm balloon as well as vascular brachytherapy (VBT) using the NovosteTH Beta-CathTM system (Novoste Corp., Norcross, GA). A 40 mm Strontium90/Yttrium90 radioactive source train was dwelled across the site of the ISR for 227 s, delivering 18.4 Gy of beta-radiation. No recurrent ISR was noted in the 6-month restudy angiogram. She remained angina free until 5 years ago and coronary angiogram revealed a focal ISR as well as a de novo 95% stenosis just distal to previous stent but within the VBT the radiation field. The ISR was treated with simple balloon angioplasty with a 3.5 mm non-compliant balloon and the de-novo lesion treated with Genous 3.0 × 23 mm stent (OrbusNeich Medical, Hoevelaken, The Netherlands) and post-dilated using a 3.5 mm non-compliant balloon under intra-vascular ultrasound (IVUS) guide.

TCT-636 Use Of Optical Coherence Tomography To Study The Role Of Non-Compliant Balloon Post-Dilation In Optimization Of Bioresorbable Vascular Scaffolds

TCT-636 Use Of Optical Coherence Tomography To Study The Role Of Non-Compliant Balloon Post-Dilation In Optimization Of Bioresorbable Vascular Scaffolds

ABSORB Biodegradable Stents Versus Second-Generation Metal Stents: A Comparison Study of 100 Complex Lesions Treated Under OCT Guidance

The aim of this study was to compare the acute performance of the PLLA ABSORB bioresorbable vascular scaffold (BVS) (Abbott Vascular, Santa Clara, California) with second-generation metal drug-eluting stents (DES) in complex coronary artery lesions. Thick polymer-based BVS have different mechanical properties than thin second-generation DES. Data on the acute performance of BVS are limited to simple coronary lesions treated in trials with strict inclusion criteria. Fifty complex coronary lesions (all type American College of Cardiology/American Heart Association B2-C) treated with a BVS undergoing a final optical coherence tomography (OCT) examination were compared with an equal number of matched lesions treated with second-generation DES. The following stent performance indexes were assessed with OCT: mean and minimal area, residual area stenosis (RAS), incomplete strut apposition (ISA), tissue prolapse, eccentricity index, symmetry index, strut fracture, and edge dissection. One hundred lesions from 73 patients were analyzed. A higher balloon diameter/reference vessel diameter ratio was used for predilation in the BVS group (p < 0.01). Most of the BVS and DESwere post-dilated with short noncompliant (NC) balloons of similar diameter. OCT showed in the BVSgroup a higher tissue prolapse area (p= 0.08) and greater incidence of ISA at the proximal edge (p=0.04) with no difference in the overall ISA. The RAS was 20.2% in the BVS group and 21.7% in the DES group (p= 0.32). There was no difference in the eccentricity index. The minimal and mean lumen areas were similar in the 2 groups. Two cases of strut fractures occurred after the BVS, whereas none was observed in the DES. Based on OCT, the BVS showed similar post-procedure area stenosis, minimal lumen area, and eccentricity index as second-generation DES. The different approach for lesion preparation and routine use of OCT guidance during BVS expansion may have contributed to these results.

Identification of Fragmented Balloon Materials in Coronary Arteries by Optical Coherence Tomography

A critical calcific mid-left anterior descending stenosis of a 54-year-old man with unstable angina was treated with a drug-eluting stent. Except for the rupture of a noncompliant balloon during post-dilation, the procedure was uneventful ([Fig. 1][1]A). Shortly before the procedure ended, however

Adjunctive Strategies in the Management of Resistant, ‘Undilatable’ Coronary Lesions After Successfully Crossing a CTO with a Guidewire

Successful revascularisation of chronic total occlusions (CTOs) remains one of the greatest challenges in the era of contemporary percutaneous coronary intervention (PCI). Such lesions are encountered with increasing frequency in current clinical practice. A predictable increase in the future burden of CTO management can be anticipated given the ageing population, increased rates of renal failure, graft failure and diabetes mellitus. Given recent advances and developments in CTO PCI management, successful recanalisation can be anticipated in the majority of procedures undertaken at high-volume centres when performed by expert operators. Despite advances in device technology, the management of resistant, calcific lesions remains one of the greatest challenges in successful CTO intervention. Established techniques to modify calcific lesions include the use of high-pressure non-compliant balloon dilation, cutting-balloons, anchor balloons and high speed rotational atherectomy (HSRA). Novel approaches have proven to be safe and technically feasible where standard approaches have failed. A step-wise progression of strategies is demonstrated, from well-recognised techniques to techniques that should only be considered when standard manoeuvres have proven unsuccessful. These methods will be described in the setting of clinical examples and include use of very high-pressure non-compliant balloon dilation, intentional balloon rupture with vessel dissection or balloon assisted micro-dissection (BAM), excimer coronary laser atherectomy (ECLA) and use of HSRA in various ‘offlabel’ settings.

TCTAP A-063 Inflammatory Effects and Clinical Outcomes of High-pressure Post-dilation with Non-compliant Balloon During Drug-eluting Stent Implantation

The acute inflammatory response of high-pressure post-dilation with non-compliant balloon (HPNC) after drug-eluting stent (DES) deployment remains still unknown. We sought to evaluate the inflammatory effects and clinical outcomes of HPNC after DES implantation. We enrolled consecutive patients

Efficacy of non-compliant balloon post-dilation in optimization of contemporary stents: A digital stent enhancement study

BackgroundThere is no evidence from randomized trials for the benefit of routine non-compliant balloon (NCB) post-dilation after stent deployment. Despite being the gold standard, intravascular ultrasound is infrequently performed due to time and cost constraints and a suitable alternative technology is required for routine assessment of stent expansion. The purpose of this study was to assess the contribution of NCB post-dilation in optimizing contemporary stents by using digital stent enhancement (DSE). MethodsWe treated 120 patients with stent insertion and assessed the stents with DSE before and after NCB use. Optimal expansion was defined as the minimum stent diameter (MSD) ≥ 90% of the nominal stent diameter, an adaptation of the MUSIC and POSTIT trial criteria. Stent deployment was performed at 12 atm pressure followed by routine NCB post-dilation at ≥ 14 atm. ResultsThe mean reference diameter on QCA was 2.75 mm (SD 0.63) and mean stent diameter was 3.15 mm (SD 0.46). At a mean stent deployment pressure of 11.7 atm (SD 2.4), only 21% of stents were optimally expanded. After NCB inflation at a mean of 16.9 atm (SD 2.8), MSD increased by 0.26 mm (SD 0.24), optimal stent expansion increased from 21% to 58% and mean stent symmetry ratio increased from 0.83 to 0.87 (p < 0.0001). ConclusionsContemporary stents are sub-optimally expanded in the majority of cases after standard deployment compared with nominal sizes. Adjunctive NCB post-dilation optimized an additional 37% of stents. DSE analysis can assist in qualitative and quantitative stent assessments and can potentially facilitate a selective NCB post-dilation strategy to achieve optimal stent expansion.

Coronary artery compression during intention to treat right ventricle outflow with percutaneous pulmonary valve implantation: Incidence, diagnosis, and outcome

Evaluate the incidence, diagnosis, and outcome of coronary compression (CC) during right-ventricular outflow tract interventions. The incidence, risk factors, diagnosis, and outcomes of CC during percutaneous pulmonary valve implantation are poorly defined. One-hundred consecutive patients (May 2008 to January 2012) undergoing transcatheter right-ventricular outflow tract treatment in two institutions were studied. CC occurred in six patients (6%) with a right ventricular outflow conduit stenosis, at a median age of 24.5 (13-49) years. It involved the left main coronary artery in four and the right coronary artery originating from the left anterior descending coronary artery in two patients. Conduit types were homograft (n = 3), bioprosthesis (n = 2), and a pericardial patch (n = 1). Median diameter was 23 (17-24) mm at surgical implantation. CC was diagnosed through a selective coronary angiogram during balloon dilation of the conduit in the first three patients and through an aortic root angiogram for the three next cases because we recognized that proximal compression could be masked during coronary artery cannulation. It was suspected on pre-procedure imaging (magnetic resonance imaging and/or computed tomography) in three cases. Patients with abnormal coronary anatomy tend to be at increased risk of CC (P = 0.0504). One institution had a higher incidence of CC (P = 0.04). CC resolved after balloon deflation. No patient underwent conduit stenting. Four patients underwent surgical reconstruction of right ventricular outflow tract. CC is accurately diagnosed during right-ventricular outflow tract interventions. We recommend an aortic root angiogram during dilation with a non-compliant balloon matching the diameter and length of the intended conduit implant.

First ad hoc bioresorbable vascular scaffold bench test: A glimpse into percutaneous bifurcation interventions

The advent of a fully bioresorbable stent has been advocated as a breakthrough in interventional cardiology [1]. After transiently assuring radial strength, this device is fully resorbed, leading to restoration of the vessel's biological properties. However, although representing a truly innovative technology, the evolutionary impact of the bioresorbable vascular scaffold (BVS) appears somewhat shadowed by its intrinsic polymeric nature, which is not designed to tolerate the mechanical stresses that metallic stents typically endure during percutaneous bifurcation interventions. Indeed the Instruction For Use (IFU) of ABSORB (Abbott Vascular, Santa Clara, CA), the only commercially availableBVS, state to “avoid scaffolding across any sidebranch≥2 mmin diameter” because “balloon dilation of any cells of a deployed BVS will cause scaffold damage”. Nevertheless, the availability of the BVS in an increasing number of catheterization laboratories has entailed a more liberal use of the device engendering the feeling that manufacturer's recommendations are excessively restrictive. Coupled to the rush for originality typically accompanying new technology, the lack of knowledge on the actual deformation capability of the BVS might be clinical harmful. Surprisingly, no bench test has been performed to date, possibly due to the high cost of the device and/or reluctance of the manufacturer to provide samples for such kind of investigation. We therefore take the opportunity of a non-implanted BVS to gain some insight into the structural features of this device, with special focus on its possible role in percutaneous bifurcation interventions. Because the IFU advised against reintroducing an ABSORB that has been retracted into the guiding catheter owing to the start of the polymer degradation process, we implemented a very simple bench test immediately after the end of the percutaneous coronary intervention, recycling the materials that have been used for the procedure. The test has been conducted in a liquid bath at body temperature (37 °C) to simulate the conditions in which the BVS inherent expansion occurs (Fig. 1A). All inflations were performed according to IFU, i.e. 2 atm increments every 5 s up to nominal pressure. After inflation of its delivery balloon, the expanded scaffold was placed over a stylet helping its manipulationwithout the need for touching. A cell was then crossed by a coronary guide wire and by a 2.5 mm diameter balloon (Fig. 1B) that was inflated. The BVS was then rapidly imaged. The scaffold showed mild dilation of the cell toward its external side with no apparent breaking of the structure (Fig. 2A and B). The same cell was further expanded with a 3.0 mm balloon inflation. Results showed a more significant modification of scaffold structure better revealing themechanism of cell dilation, i.e. up and down displacements of the ring arc delimiting the cell determining a small reduction of the scaffold internal caliber (Fig. 3A and B). To further assess the potential role of ABSORB in the treatment of bifurcation lesions, we over-expanded the segment starting from the dilated cell with a 3.5 mm and a 4.0 mm non-compliant balloon (respectively 0.5 mm and 1.0 mm larger than the nominal diameter of

Coronary Stent Fracture Complicated Multiple Aneurysms Confirmed by 3-Dimensional Reconstruction of Intravascular-Optical Coherence Tomography in a Patient Treated With Open-Cell Designed Drug-Eluting Stent

A 55-year-old man with a previous history of cerebral infarct and hypertension presented to our cardiovascular center complaining of angina in November 2011. Chronic total occlusion in the proximal left anterior descending artery was identified by coronary angiography (Figure 1A). The patient subsequently underwent percutaneous coronary intervention. Wiring was done successfully with a tapered stiff wire (Conquest Pro 20; ASAHI INTECC). After multiple predilation, a single drug-eluting stent (3.0 × 18 mm) of an open-cell design and bioabsorbable polymer (Nobori; Terumo, Tokyo, Japan) was implanted using a 3.5-mm noncompliant balloon (inflation pressure, 24 atmospheric pressure; Quantum Maverick Balloon; Boston Scientific/Scimed, Maple Grove, MN) for application of final high-pressure postdilation (Figure 1B). The patient has been asymptomatic since percutaneous coronary intervention and on dual antiplatelet therapy. A 6-month scheduled angiographic follow-up demonstrated a structural misalignment at the stent implantation site with a change in focal aneurysm (Figure 1C). Digital subtraction imaging by StentBoost (Subtract; Philips Healthcare, Best, The Netherlands) was done under the suspicion of stent distortion, but the imaging was unclear to clarify the diagnosis (Figure 1D). To determine the precise configuration of the stent, we performed intravascular optical coherence tomography (OCT). Conventional 2-dimensional (2-D) OCT revealed a focal thrombus and 2 additional aneurysms …

Noncompliant balloonによる血管形成術の発展性

Noncompliant balloonによる血管形成術の発展性

A qualified weapon in the fight against challenging coronary artery lesions: Rotablator® device

Atherectomy is a procedure that clears blockages in the coronary arteries in order to improve blood flow to the heart and relieve symptoms of coronary artery disease. The procedure may be performed instead of or in addition to other procedures and can improve both the immediate and long-term success of balloon angioplasty and stenting. Although it is no longer a common procedure, it does play an important role in interventional cardiology. When the challenging atherosclerotic coronary artery lesions cannot be crossed by a balloon or cannot be adequately dilated even with non-compliant balloon, such lesions may be better treated by rota-ablation, which is carried out by operators who are experienced in rotational atherectomy.

Finite element analysis of the percutaneous coronary intervention in a coronary bifurcation.

The paper presents the process of numerical modeling and simulation of balloon angioplasty of the coronary artery using Finite Element Method. The authors focused on the issue of applying adequate pressure in an arterial tissue during the post-dilatation process in the "kissing balloon" stenting technique applied to patients with bifurcation stenosis. Despite great progress in the field of interventional cardiology, angioplasty in bifurcations still belongs to the most difficult interventions, generally being less effective and more risky than in the cases of straight stenosis. During the modeling procedures and further simulations, the authors focused on mutual cooperation of non-compliant angioplasty balloons and the coronary artery. The other goal was to develop a sufficiently accurate model of the coronary artery fragment, including its bifurcation and angioplasty balloons; however, it was decided to ignore the modeling of coronary stents. The issue undertaken is considered as relatively complicated and complex but, in the authors' opinion, the implementation of advanced computer aided engineering techniques may, in this case, answer several important questions without the need of performing costly and aggravating in vivo tests.

術後肺動脈狭窄に対するnoncompliant balloonの有効性に関する検討

背景：先天性心疾患術後の肺動脈狭窄に対するバルーン拡大術 balloon dilatation （BD）は，術後肺循環の改善を目指すうえで重要な治療戦略である．最近では，従来よりもカテーテルの追従性が良いnoncompliant balloons（NBs）が開発され，その使用が広まってきている．目的：術後肺動脈狭窄に対するNBの有効性を，semi-compliant balloons（SBs）と比較し検証する．方法：2007年4月から2013年4月の間に当院でBDを行った術後肺動脈狭窄136症例154病変を対象に，後方視的に検討した．結果：術後肺動脈狭窄に対するBDの内訳は，SB群70症例78病変，NB群66症例76病変であった．BD後のwaist解除率は，SB群で45％に対しNB群では80％（p < 0.001）と，NB群で有意にwaistを解除し得た．一方，使用されたバルーンサイズの最狭窄部径に対する比率では，SB群で259 ± 6.6％に対しNB群では214.9 ± 6.1％（p < 0.001）と，NB群においてより小さなバルーンサイズ比率で有効な拡大が得られていた．結論：NBは，SBよりも小さなバルーンサイズ比率でより確実に狭窄を解除し得る．

Clinical effects of routine postdilatation of drug‐eluting stents

To assess the clinical effects of postdilatation of drug-eluting stents (DES). Subotpimal stent expansion occurs after DES deployment. Postidlatation may improve DES expansion, but it is unclear whether postdilatation may also improve clinical outcomes. Since July 2009, we adopted a strategy of routine postdilatation with noncompliant balloons of all DES, while previously postdilatation was performed only for suboptimal results. The first 279 consecutive patients (age 62 ± 9 years, 231 men) who underwent routine postilatation were compared with 262 patients (age 61 ± 9 years, 220 men) who received DES in the previous 6 months (standard treatment). The two groups were similar for age, sex, clinical presentation, and main risk factors, including incidence of diabetes. Routine postdilatation resulted in an improved minimal lumen diameter at the end of the procedure (2.60 ± 0.34 vs. 2.51 ± 0.37 mm, P = 0.003). At 12-month follow-up incidence of MACE (including periprocedural myocardial infarction) was 19.5% in the standard treatment group and 12.5% in routine postdilatation group (P = 0.04), with a significant difference in target vessel revascularization (10.7% vs. 5.4%, P = 0.03), while incidence of myocardial infarction was not significantly different between the two groups (10.7% vs. 9.3%, P = 0.70). Stent thrombosis (definite or probable) occurred in 3 patients in standard treatment group, while no case of stent thrombosis occurred among patients treated with routine postdilatation (1.1% vs. 0%, P = 0.11). Our results suggest that a strategy of routine postdilatation with non compliant balloons may improve clinical outcomes of DES.

A coronary “tunnel”: Optical coherence tomography assessment after rotational atherectomy

A 81-year-old woman was admitted for exertional angina. Coronary angiogram revealed a severely calcific proximal circumflex lesion. Rotational atherectomy was performed with 1.5 and 1.75 burrs, obtaining a good angiographic result. Optical coherence tomography (OCT) assessment revealed a large dissection parallel to the true lumen. We implanted a 3.0 mm × 38 mm Xience Prime(®) stent and postdilated it with a 3.0-mm non-compliant balloon. Final OCT pullback showed mild malapposed struts with large lumen area. 3D-OCT reconstruction confirmed a large lumen after stent implantation.

Excimer Laser LEsion Modification to Expand Non-dilatable sTents: The ELLEMENT Registry

Stent underexpansion is a risk factor for in-stent restenosis and stent thrombosis. Existing techniques to optimize stent expansion are sometimes ineffective. The aim of this study was to evaluate the effectiveness and feasibility of Excimer Laser Coronary Angioplasty (ELCA) in improving stent expansion when high-pressure non-compliant balloon inflation was ineffective. ECLA ablation was performed at high energy during contrast injection and only within the underexpanded stent. The primary endpoint of successful laser dilatation was defined as an increase of at least 1mm(2) in minimal stent cross-sectional area (MSA) on IVUS or an increase of at least 20% in minimal stent diameter (MSD) by QCA, following redilatation with the same non-compliant balloon that had been unsuccessful prior to ELCA. Secondary endpoints were cardiac death, myocardial infarction (MI) and target lesion revascularization. Between June 2009 and November 2011, 28 patients with an underexpanded stent despite high-pressure balloon inflation were included. The mean laser catheter size was 1.2±0.4 (range 0.9-2.0mm) and a mean of 62±12mJ/mm(2) at 62±21hertz were required for optimal expansion. Laser-assisted stent dilatation was successful in 27 cases (96.4%), with an improvement in MSD by QCA (1.6±0.6mm at baseline to 2.6±0.6mm post-procedure) and MSA by IVUS (3.5±1.1mm(2) to 7.1±1.9mm(2)). Periprocedural MI occurred in 7.1%, transient slow-flow in 3.6% and ST elevation in 3.6%. During follow-up, there were no MIs, there was 1 cardiac-death, and TLR occurred in 6.7%. The ELLEMENT study confirms the feasibility of ELCA with contrast injection to improve stent underexpansion in undilatable stented lesions.

Volumetric Laser Endomicroscopy (VLE): An OFDI Case Study of Barrettʼs Esophagus with Dysplasia

Figure: No Caption available.Purpose: Optimal diagnosis and surveillance of patients with Barrett's esophagus (BE) is complex, given that few patients undergoing resection of esophageal adenocarcinoma have a prior diagnosis of Barrett's esophagus (BE) and, among those who have been screened and diagnosed with BE, >90% never develop adenocarcinoma. Surveillance of patients with BE is further complicated by variability in the distribution of dysplasia and cancer within the esophagus. Random sampling of esophageal biopsies can result in missed regions of interest with pathology. Thus, a significant need exists for more accurate methods of identifying areas of dysplasia in the endoscopic screening and surveillance of BE. Volumetric laser endomicroscopy uses the principles of optical coherence tomography to generate high-resolution, cross-sectional, and longitudinal images of tissue microstructures simultaneously in real time. Methods: The console generates the near infrared light and transmits the light into the VLE catheter. The console includes the swept light source, optical receiver and interferometer, data acquisition computer and control electronics, and user interface and display. The catheter is a long catheter (2.5 m) plugs into the console and has a polymer, noncompliant balloon with soft tip. Results: In this case, a 64-year-old man with long standing acid reflux and a family history esophageal carcinoma had undergone endoscopy documenting long segment BE with areas suspicious for HGD and/or carcinoma. At our institution, he underwent video endoscopy with VLE imaging documenting abnormal crypt formation and surface maturation consistent with BE HGD and focal mass treated with endoscopic resection. Conclusion: Optical coherence tomography (OCT) is an imaging modality that has the ability to improve the current paradigm for endoscopic screening and surveillance. The benefit of OCT over ultrasound is that it is capable of generating cross-sectional images of tissues with an axial-resolution of up to 10 microns, which is comparable to low-power microscopy. Original OCT systems or time-domain OCT were limited to discrete locations or ‘point' sampling due to slow acquisition rates. However, with the development of second-generation OCT, termed optical frequency domain Imaging (OFDI) now called VLE, it is now possible to perform high-speed acquisition of large luminal surfaces in three-dimensions. Due to its high-resolution and high-acquisition rates, utilizing this technique for screening and surveillance of Barrett's esophagus may provide a means to evaluate pathologic states of the esophageal lumen in real-time. Disclosure - Leslie Blackshear, E Aranda-Michel, Mayo Clinic Florida: None MB Wallace, HC Wolfsen, Mayo Clinic Florida and G Tearney Massachusetts General Hospital: Grant/Research Support. This research was supported by an industry grant from Nine Point Medical, Cambridge MA.

Guide-catheter extension system facilitated multiple bioresorbable vascular scaffolds (ABSORB®) delivery in a very long and resistant coronary artery lesion

We report the case of a 77-year-old male patient who was admitted to our institution for non-ST segment elevation myocardial infarction. Coronary angiography showed a sub-occlusive lesion of the distal left anterior descending artery (LAD) in the context of a diffuse atherosclerotic disease involving a very long segment of the vessel (about 80mm in length by visual estimation). Pre-dilatation was performed in the mid calcified segment of the LAD with a non-compliant balloon inducing vessel dissection. An everolimus-eluting bioresorbable vascular scaffold (EEBVS) was then advanced in the LAD but the first delivery attempt at the distal site failed because of friction between the EEBVS struts and the calcified vessel wall. In order to facilitate EEBVS delivery, a 5Fr catheter system (Heart Rail II, Terumo, Tokyo, Japan) was advanced in the mid LAD within a standard 6Fr guiding catheter facilitating a non-traumatic deep intubation up to the mid LAD. This strategy increased back-up support facilitating the delivery, beyond the site of resistance, of four EEBVS implanted in overlap. This case demonstrated the successful use of a guide catheter extension system to deliver multiple EEBVS in a patient with a long, calcified LAD lesion.

Endovascular Stent Placement of Juxtaanastomotic Stenosis in Native Arteriovenous Fistula After Unsuccessful Balloon Angioplasty

BackgroundIn hemodialysis patients, the most common problem in arteriovenous fistulas, as the best functional vascular access, is the juxtaanastomotic located lesions. Percutaneous transluminal angioplasty is accepted as the treatment method for juxtanastomotic lesions.ObjectivesTo assess juxtaanastomotic stent placement after insufficient balloon angioplasty in the treatment of autogenous radiocephalic or brachiocephalic fistula dysfunction.Patients and MethodsBetween July 2003 and June 2010, 20 hemodialysis patients with autogenous radiocephalic or brachiocephalic fistula dysfunction underwent stent placement for the lesion located at the juxtaanastomotic region. Indications for stent placement were insufficient balloon dilatation, early recurring stenosis, chronic organizing thrombus and vessel rupture. The Kaplan-Meier method was used to calculate the stent patency rates. All patients who had fistula dysfunction (thrombosis of hemodialysis access, difficult access cannulation, extremity pain due to thrombosis or decreased arterial access blood flow) were evaluated by color Doppler ultrasound. The stenoses were initially dilated with standard noncompliant balloons (3 to 10-mm in diameter). Dilatation was followed by high pressure (Blue Max, Boston Scientific) or cutting balloons (Boston Scientific), if the standard balloon failed to dilate the stenotic segment.ResultsTwenty-one stents were applied. The anatomical and clinical success rate was 100%. Seventeen additional interventions were done for 11 (55%) patients due to stent thrombosis or stenosis during follow-up. Our 1- and 2-year secondary patency rates were 76.2% and 65.5%, respectively and were comparable to those after balloon angioplasty and surgical shunt revision.ConclusionMetallic stent placement is a safe and effective procedure for salvage of native hemodialysis fistula after unsuccessful balloon angioplasty.