Standard Balloon Angioplasty Research Articles

Superiority of Stent-Grafts for In-Stent Restenosis in the Superficial Femoral Artery

Purpose: To evaluate the short- and midterm outcomes of the Viabahn endoprosthesis with Propaten Bioactive Surface vs. standard balloon angioplasty for treatment of in-stent restenosis in the superficial femoral artery. Methods: Between June 2010 and February 2012, 83 patients with superficial femoral artery in-stent and Rutherford category 2 to 5 ischemia were enrolled at 7 sites participating in this prospective randomized controlled study (RELINE; ClinicalTrials.gov; identifier NCT01108861). The patients were randomized to treatment with either the heparin-bonded Viabahn endoprosthesis (n=39: 29 men; mean age 67.7±9.8 years) or a standard angioplasty balloon (n=44: 32 men; mean age 69.0±9.7 years). The primary effectiveness outcome was primary patency at 12 months, defined as no restenosis/occlusion within the target lesion based on duplex ultrasound and no target lesion revascularization. The primary safety endpoint was the incidence of serious device-related adverse events within 30 days of the procedure. Results: All patients randomized to receive dilation or the Viabahn stent-graft were treated according to their assignment. The technical success was 100% for the Viabahn group and 81.8% for the angioplasty group (p=0.002) owing to 9 patients requiring a bailout procedure after unsuccessful angioplasty. The 12-month primary patency rates were 74.8% for the Viabahn group and 28.0% for the angioplasty group (p<0.001). Excluding the 9 angioplasty patients who received bailout stenting, the primary patency for optimal balloon angioplasty was 37.0% (p<0.001). Three patients experienced device-related adverse events within 30 days: occlusion of the target lesion (Viabahn group), peripheral embolization (angioplasty group), and reocclusion of the target lesion (angioplasty group). Conclusion: In this study, the treatment of femoropopliteal in-stent restenosis with a Viabahn endoprosthesis showed significantly better results than treatment with a standard balloon at 1 year.

Paclitaxel-Coated Balloon Angioplasty for Symptomatic Central Vein Restenosis in Patients With Hemodialysis Fistulas

Purpose: To report a retrospective observational analysis of standard balloon angioplasty (BA) vs. paclitaxel-coated balloon angioplasty (PCBA) for symptomatic central vein restenoses in patients with impaired native hemodialysis fistulas. Methods: A retrospective review was conducted of 27 consecutive patients (15 men; mean age 66±13.8 years, range 39–90) with 32 central vein stenoses (CVS; 6 axillary, 11 subclavian, 12 brachiocephalic, and/or 3 superior caval veins) treated successfully using BA. Freedom from reintervention after BA of de novo lesions was 7.4±7.9 months (range 1–24). Twenty-five (92.6%) patients developed symptomatic restenoses and were treated one or more times by BA (n=32) or PCBA (n=20) using custom-made paclitaxel-coated balloons (diameter 6–14 mm). Results: Technical (<30% residual stenosis) and clinical (functional fistula) success rates for the initial and secondary angioplasty procedures were 100%. No minor/major procedure-associated complications occurred. Mean follow-up was 18.4±17.5 months. Kaplan-Meier analysis for freedom from target lesion revascularization (TLR) found PCBA superior to BA (p=0.029). Median freedom from TLR after BA was 5 months; after PCBA, >50% of patients were event-free during the observation period (mean freedom from TLR 10 months). Restenosis intervals were prolonged by PCBA (median 9 months) vs. BA (median 4 months; p=0.023). Conclusion: Paclitaxel-coated balloon angioplasty of central vein restenosis in patients with hemodialysis shunts yields a statistically significant longer freedom from TLR compared to standard balloon angioplasty.

Overview of the 2014 Food and Drug Administration Circulatory System Devices Panel meeting regarding the Lutonix® drug coated balloon.

The Lutonix® drug coated balloon (DCB) is a combination device composed of a standard percutaneous angioplasty balloon coated with paclitaxel. Depending on the balloon size, a dose density of 2μg/mm(2) yields a variable total dose raging from 1.5mg to 3.8mg. This drug coated balloon aims to provide improved patency rates in patients with symptomatic femoropopliteal de novo or restenotic atherosclerotic disease. On June 12, 2014, the Food and Drug Administration's (FDA) Circulatory System Devices Panel reviewed the Lutonix DCB premarket approval application (PMA). This PMA application was primarily based on data from the pivotal randomized, controlled and multicenter clinical trial, which compared the Lutonix DCB with PTA. This summary aims to describe the discussions and recommendations made by the advisory panel during the meeting. Based on the Panel's recommendations, it is possible that the FDA will approve this device.

TCT-155 A Novel Multi Lumen Compliant Balloon Catheter (ND® Infusion Catheter) Preserves Stem Cell Viability and Improves Dispersion When Compared to a Standard Single Lumen Balloon Angioplasty Catheter

TCT-155 A Novel Multi Lumen Compliant Balloon Catheter (ND® Infusion Catheter) Preserves Stem Cell Viability and Improves Dispersion When Compared to a Standard Single Lumen Balloon Angioplasty Catheter

IN.PACT Amphirion paclitaxel eluting balloon versus standard percutaneous transluminal angioplasty for infrapopliteal revascularization of critical limb ischemia: rationale and protocol for an ongoing randomized controlled trial

BackgroundThe effectiveness and durability of endovascular revascularization therapies for chronic critical limb ischemia (CLI) are challenged by the extensive burden of infrapopliteal arterial disease and lesion-related characteristics (e.g., severe calcification, chronic total occlusions), which frequently result in poor clinical outcomes. While infrapopliteal vessel patency directly affects pain relief and wound healing, sustained patency and extravascular care both contribute to the ultimate “patient-centric” outcomes of functional limb preservation, mobility and quality of life (QoL).Methods/DesignIN.PACT DEEP is a 2:1 randomized controlled trial designed to assess the efficacy and safety of infrapopliteal arterial revascularization between the IN.PACT Amphirion™ paclitaxel drug-eluting balloon (IA-DEB) and standard balloon angioplasty (PTA) in patients with Rutherford Class 4-5-6 CLI.DiscussionThis multicenter trial has enrolled 358 patients at 13 European centers with independent angiographic core lab adjudication of the primary efficacy endpoint of target lesion late luminal loss (LLL) and clinically driven target lesion revascularization (TLR) in major amputation-free surviving patients through 12-months. An independent wound core lab will evaluate all ischemic wounds to assess the extent of healing and time to healing at 1, 6, and 12 months. A QoL questionnaire including a pain scale will assess changes from baseline scores through 12 months. A Clinical Events Committee and Data Safety Monitoring Board will adjudicate the composite primary safety endpoints of all-cause death, major amputation, and clinically driven TLR at 6 months and other trial endpoints and supervise patient safety throughout the study. All patients will be followed for 5 years. A literature review is presented of the current status of endovascular treatment of CLI with drug-eluting balloon and standard PTA. The rationale and design of the IN.PACT DEEP Trial are discussed. IN.PACT DEEP is a milestone, prospective, randomized, robust, independent core lab-adjudicated CLI trial that will evaluate the role of a new infrapopliteal revascularization technology, the IA-DEB, compared to PTA. It will assess the overall impact on infrapopliteal artery patency, limb salvage, wound healing, pain control, QoL, and patient mobility. The 1-year results of the adjudicated co-primary and secondary endpoints will be available in 2014.Trial registrationNCT00941733

A Randomized, Controlled Animal Trial Demonstrating the Feasibility and Safety of the Magellan™ Endovascular Robotic System

The success of remotely steerable catheters designed for cardiac ablation procedures in the peripheral vasculature (in the laboratory and in highly select live cases) has led to the development of a vascular robotic system designed specifically for use in the arterial and venous systems. Limited bench-top and animal testing has been successful, but no randomized, controlled study of the system's safety has been performed. In a 3-phase study, we performed a randomized, controlled trial comparing standard manual catheterization and balloon angioplasty of visceral, renal, and contralateral lower extremity vessels in a porcine model. We also demonstrated feasibility of standard device deployment through the system. There was 100% technical success in test (robotic) and control (manual) arm cannulation and balloon angioplasty of all target vessels, without complications. Pathologic analysis at 7 days revealed significantly fewer traumatic lesions in the test animal arm as compared with the control arm (P < 0.001) and, by 30 days, all lesions had healed in both groups. There was 100% success in delivery of standard devices (balloons and stents) without complications. Remotely steerable robotic catheters are at least as safe as manual catheter techniques, and may prove less traumatic to peripheral vessels. Standard devices can be deployed through the system, and the stability of the platform may aid in ease of device delivery in difficult vascular segments.

The Design of an Improved Force Focused Angioplasty Catheter

Atherosclerosis is a disease that causes obstructions to develop within the arterial system; these obstructions can result in an acute vascular event such as a heart attack or stroke, and potentially death. In the majority of cases a standard angioplasty balloon is sufficient to dilate the site of an obstruction; however difficult obstructions, such as heavily calcified lesions require specialist dilation solutions. One such example of a device is Boston Scientific's cutting balloon. An analysis of the Food and Drug Administration's (FDA) Manufacturer and User Facility Device Experience (MAUDE) database demonstrates that the original cutting balloon has a number of distinct adverse events associated with it. In this study we describe the design, manufacturing, and testing of a new force focused angioplasty balloon that has the potential to reduce or eliminate the adverse events associated with the Boston Scientific cutting balloon. This design incorporates two elastomeric materials to aid recoiling of the device namely: nitinol and a silicone elastomer. New methods of manufacturing are described in this study, that ensure that precision molding and assembly can occur. To determine the effectiveness of our device, we simulated concentric calcified lesions with a surrogate chalk model. These results demonstrate that our device has a significantly lower lesion burst pressure in comparison to a standard angioplasty balloon, 174 atm versus 12.48 atm. To determine if our device reduced potential snagging, and thus reduced the risk of withdrawal resistance being encountered, we performed a withdrawal resistance test. A noticeably lower withdrawal force is associated with our device, the high peaks on the Boston Scientific device indicate that there may be wings forming on the balloon and these are catching on the tip of the introducer sheath. Finally, we demonstrated in vivo efficacy of our device in a porcine model. By the use of elastomeric recoiling features in a new cutting balloon design we have been able to overcome the three main reported adverse events associated with the Boston Scientific cutting balloon. Subsequently we experimentally demonstrated this improved efficacy for one particular peripheral balloon size (e.g., 5 mm diameter).

Cost-Effectiveness Analysis of Paclitaxel-Coated Balloons for Endovascular Therapy of Femoropopliteal Arterial Obstructions

To explore the cost-effectiveness of using drug-eluting balloon (DEB) angioplasty for the treatment of femoropopliteal arterial lesions, which has been shown to significantly lower the rates of target lesion revascularization (TLR) compared with standard balloon angioplasty (BA). A simplified decision-analytic model based on TLR rates reported in the literature was applied to baseline and follow-up costs associated with in-hospital patient treatment during 1 year of follow-up. Costs were expressed in Swiss Francs (sFr) and calculated per 100 patients treated. Budgets were analyzed in the context of current SwissDRG reimbursement figures and calculated from two different perspectives: a general budget on total treatment costs (third-party healthcare payer) as well as a budget focusing on the physician/facility provider perspective. After 1 year, use of DEB was associated with substantially lower total inpatient treatment costs when compared with BA (sFr 861,916 vs. sFr 951,877) despite the need for a greater investment at baseline related to higher prices for DEBs. In the absence of dedicated reimbursement incentives, however, use of DEB was shown to be the financially less favorable treatment approach from the physician/facility provider perspective (12-month total earnings: sFr 179,238 vs. sFr 333,678). Use of DEBs may be cost-effective through prevention of TLR at 1 year of follow-up. The introduction of dedicated financial incentives aimed at improving DEB reimbursements may help lower total healthcare costs.

TCT-449 COMPARISON OF PACLITAXEL-ELUTING BALLOONS WITH DRUG-ELUTING STENTS FOR TREATMENT OF IN-STENT RESTENOSIS: A RETROSPECTIVE ANALYSIS OF AN ALL-COMERS COHORT

The optimal treatment strategy for coronary in-stent restenosis (ISR) is unclear. Drug-eluting balloons (DEB) offer an alternative to drug-eluting stents (DES) by avoiding risks of stent thrombosis, and by lowering the risks of restenosis associated with standard balloon angioplasty and bare-metal

Cryoplasty offers no advantage over standard balloon angioplasty for the treatment of in-stent stenosis

In-stent restenosis is the primary failure mode of endovascular treatment of occlusive disease in the femeropopliteal segment. Cryoplasty has been proposed to reduce intimal hyperplasia through induction of apoptosis. We sought to evaluate the efficacy of cryoplasty for treatment of in-stent restenosis compared to conventional balloon angioplasty (CBA). After IRB approval, a retrospective record review was performed of reinterventions for in-stent restenosis by a single vascular surgery group at a university hospital. Reinterventions involving cryoplasty and CBA were evaluated at 1, 3, 6 and 12 months after intervention with duplex imaging to identify significant recurrent stenosis utilizing established velocity criteria. Data collected included basic demographic information and comorbidities as well as time to restenosis. Statistical analysis was performed using Kaplan–Meier survival curves with the log rank test, Wilcoxon rank test, and Cox proportional hazards models. From December 2004 to November 2007, 76 reinterventions were performed using CBA (n = 39) or cryoplasty (n = 37) for in-stent restenosis without placement of additional stents. Periprocedural technical success (>30% residual stenosis) was 100% for both groups, with no complications. The two cohorts were statistically similar in mean age, gender, comorbidities, tobacco use and use of statins, aspirin and Plavix. However, the mean lesion length was significantly longer in the cryoplasty cohort (CBA: 140.9 mm, Cyro: 191.7 mm; P = 0.032). The mean time to recurrent stenosis or need for additional secondary intervention was significantly shorter for the cyroplasty cohort than for the CBA, 4.09 and 10.79 months, respectively (P = .0001). Recurrent stenosis-free survival was significantly lower in the cyroplasty cohort at 3 months (CBA: 96.9%, Cyro: 88.9%) and 6 months (CBA: 84.0%, Cyro: 43.8%; P = .0089). Cyroplasty as a modality for treatment of in-stent stenosis in the femoropopliteal segment offers no benefit over CBA.

Ultrasonic resonant modes of piezoelectric balloons under internal pressure

Properties of a piezoelectric polymeric angioplasty balloon that may decrease the problems of acute closure and restenosis are evaluated in this study. Polyvinylidene difluoride (PVDF), a piezoelectric and pyroelectric polymer, has sufficient strength to serve as a standard angioplasty balloon as well as functioning as an ultrasonic transmitter and/or receiver. These properties enable potential therapeutic applications using ultrasound such as plaque ablation and sonotherapy as well as vulnerable plaque diagnosis using thermography. This study investigates the resonant structure of the PVDF balloon catheter in the frequency range 5-100 kHz. Vibrations of the piezoelectric balloon are modeled using cylindrical shell theory and compared with the observed modal frequencies of PVDF cylinders with and without internal pressure. Modal frequencies are determined by measuring the near-field pressure response of the PVDF cylinders using a high frequency microphone. A rich nodal structure is observed between 5 and 100 kHz with peak relative amplitudes measured between 42 and 45 kHz. Higher order modes for cylinders with 9 μm and 28 μm wall thickness increase in frequency as the internal pressure is increased. Experimental measurements confirm theoretical models that predict both pressure-dependent and pressure-independent resonant frequencies. Frequencies of pressure-dependent modes are calculated within 2.2% of measured values at high pressure.

Peripheral Applications of Drug-Coated Balloons: Past, Present and Future

Drug-coated balloon (DCB) technologies represent the latest and hottest development in the field of endovascular treatment of peripheral arterial disease. Initial experience with paclitaxel-coated balloon use in the femoral artery has demonstrated lower mid-term restenosis and superior mid-term clinical outcomes in terms of improved wound healing and reduced repeat angioplasty rates compared with standard balloon angioplasty. Many companies are presently developing and/or improving DCB catheters and therefore ongoing, technical improvements of the already existing platforms, new drugs, and innovative carriers are expected. The ongoing basic research studies and various multicenter randomized, controlled trials that are currently in progress will offer valuable scientific insights regarding the long-term effectiveness and other crucial issues, such as efficacy in various vascular beds, optimal balloon dosage, and post angioplasty antiplatelet therapy. Future applications of these devices also could include in-stent restenosis, anastomotic stenosis of surgical bypass, and benign stenoses of the central venous system. The authors envision that DCB angioplasty will evolve to a major paradigm shift in the endovascular treatment of occlusive vascular diseases.

Paclitaxel-Coated Balloon Angioplasty vs. Plain Balloon Dilation for the Treatment of Failing Dialysis Access:6-Month Interim Results From a Prospective Randomized Controlled Trial

To report the 6-month results of a prospective randomized trial investigating angioplasty with paclitaxel-coated balloons (PCB) vs. plain balloon angioplasty (BA) for the treatment of failing native arteriovenous fistulae (AVF) or prosthetic arteriovenous grafts (AVG). The enrollment criteria for this non-inferiority hypothesis trial included clinical signs of failing dialysis access with angiographic documentation of a significant venous stenotic lesion in patients with AVF or AVG circuits. From March to December 2010, 40 patients (29 men; mean age 64.1 ± 14.3 years) were randomized to undergo either PCB dilation (n = 20) or standard BA (n = 20) of a stenosed venous outflow lesion. Regular angiographic follow-up was scheduled bimonthly. Study outcome measures included device success (<30% residual stenosis without postdilation), procedural success (<30% residual stenosis), and primary patency of the treated lesion (<50% angiographic restenosis and no need for any interim repeat procedures). Baseline and procedural variables were comparably distributed between both groups. Device success was 9/20 (45%) for the PCB device vs. 20/20 (100%) for standard control BA (p<0.001). Procedural success was 100% in both groups after further high-pressure post-dilation as necessary. There were no major or minor complications in either group. At 6 months, cumulative target lesion primary patency was significantly higher after PCB application (70% in PCB group vs. 25% in BA group, p<0.001; HR 0.30, 95% CI 0.12 to 0.71, p<0.006). PCB angioplasty improves patency after angioplasty of venous stenoses of failing vascular access used for dialysis.

Below-the-knee drug-eluting stents and drug-coated balloons

Endovascular procedures have evolved to the mainstream treatment of choice for revascularization of infrapopliteal obstructive disease, especially in patients suffering from critical limb ischemia and multiple comorbidities. However, standard balloon angioplasty is limited by the potential of a suboptimal acute outcome due to elastic recoil and/or flow-limiting dissection, followed by neointimal hyperplasia and progressive vascular restenosis even in the case of bare-metal stent use. Drug-eluting stents and drug-coated balloons are emerging endovascular technologies with the promise of significant inhibition of vessel restenosis and improved clinical outcomes. The current review outlines the drug-eluting properties of those instruments and summarizes the currently available clinical data. The authors critically appraise the current status and also provide a glimpse of the near future of endovascular below-the-knee treatments.

First Experience With Drug-Eluting Balloons in Infrapopliteal Arteries: Restenosis Rate and Clinical Outcome

The purpose of this study was to investigate the efficacy of drug-eluting balloons (DEBs) in the treatment of long infrapopliteal lesions with regard to the short-term restenosis rate and midterm clinical result. Restenosis rates of long-segment tibial artery disease are very high. Recently, a restenosis rate of 69% at 3 months after standard balloon angioplasty was demonstrated. Infrapopliteal angioplasty was performed with a paclitaxel-eluting balloon (In.Pact Amphirion, Medtronic, Minneapolis, Minnesota). Clinical and angiographic follow-up was performed at 3 months to detect binary restenosis, and further clinical assessment was performed over a 12-month period thereafter. In 104 patients, 109 limbs were treated for critical limb ischemia (82.6%) or severe claudication (17.4%). Mean lesion length of the arteries treated was 176 ± 88 mm. Angiography studied in 84 treated arteries at 3 months showed a restenosis in 27.4% (19.1% had restenosis of more than 50%, and 8.3% were totally occluded) and usually occurred focally. Only in 9.5% of all angiographically followed up arteries was the entire treated segment restenosed or reoccluded. During a follow-up period of 378 ± 65 days, 1 patient was lost and 17 died. Of the 91 limbs remaining in the analysis, clinical improvement was present in 83 (91.2%). Complete wound healing occurred in 74.2%, whereas major amputation occurred in 4 patients, resulting in limb salvage of 95.6% for patients with critical limb ischemia. The early restenosis rate of long-segment infrapopliteal disease is significantly lower after treatment with DEBs compared with historical data using uncoated balloons. Randomized trials are required to show whether this difference will lead to improvement in clinical outcomes.

Balloon-trapped Technique for Successful OptEase Filter Retrieval

To describe a case of successful retrieval of OptEase filter, using the balloon-trapped technique, after failure of its retrieval by the standard techniques. An 82-year-old man had an inferior vena cava filter placed for deep venous thrombosis prophylactically. Seven days after successful catheter-directed thrombolysis, the filter was retrieved after changing the position to caudal, using a standard angioplasty balloon. The patient was discharged on warfarin anticoagulant. Balloon-trapped removal of the OptEase filter that failed standard retrieval attempt is an effective and safe technique that can be performed using commonly available tools and familiar to most interventionalists.

Haskal ZJ, Trerotola S, Dolmatch B, et al. Stent graft versus balloon angioplasty for failing dialysis-access grafts. N Engl J Med. 2010;362:494-503

Background. The leading cause of failure of a prosthetic arteriovenous hemodialysis-access graft is venous anastomotic stenosis. Balloon angioplasty, the first-line therapy, has a tendency to lead to subsequent recoil and restenosis; however, no other therapies have yet proved to be more effective. This study was designed to compare conventional balloon angioplasty with an expanded polytetrafluoroethylene endovascular stent graft for revision of venous anastomotic stenosis in failing hemodialysis grafts. Methods. We conducted a prospective, multicenter trial, randomly assigning 190 patients who were undergoing hemodialysis and who had a venous anastomotic stenosis to undergo either balloon angioplasty alone or balloon angioplasty plus placement of the stent graft. Primary end points included patency of the treatment area and patency of the entire vascular access circuit. Results. At 6 months, the incidence of patency of the treatment area was significantly greater in the stent-graft group than in the balloon-angioplasty group (5 1% vs. 23%, P < 0.001), as was the incidence of patency of the access circuit (38% vs. 20%, P=0.008). In addition, the incidence of freedom from subsequent interventions at 6 months was significantly greater in the stent-graft group than in the balloon-angioplasty group (32% vs. 16%, P = 0.03 by the log-rank test and P = 0.04 by the Wilcoxon rank-sum test). The incidence of binary restenosis at 6 months was greater in the balloon-angioplasty group than in the stent-graft group (78% vs. 28%, P < 0.001). The incidences of adverse events at 6 months were equivalent in the two treatment groups, with the exception of restenosis, which occurred more frequently in the balloon-angioplasty group (P < 0.001). Conclusions. In this study, percutaneous revision of venous anastomotic stenosis in patients with a prosthetic hemodialysis graft was improved with the use of a stent graft, which appears to provide longer-term and superior patency and freedom from repeat interventions than standard balloon angioplasty. (ClinicalTrials.gov number, NCT00678249.).

Drug-Coated Balloons for the Prevention of Vascular Restenosis

From early in the history of percutaneous cardiovascular intervention, restenosis has been one of the most important clinical and biological measures of success, and a great deal of effort has been put into understanding the mechanisms responsible.1,2 Restenosis is the result of the interaction of a variety of mechanical and biological processes that begin immediately after balloon injury, including early vessel recoil,3,4 negative vascular remodeling,5 and excessive neointimal proliferation.5–7 The most important limitations of balloon angioplasty, abrupt vessel closure resulting from elastic recoil and occlusive plaque dissection, were effectively solved by the introduction of balloon-expandable stents.8 However, in-stent restenosis (ISR), the result of the initial injury and the vascular response to the implanted metallic prosthesis leading to excessive neointimal proliferation, remained as the most important cause of failure of these devices.9,10 Drug-eluting stents (DES) effectively reduced ISR by addressing the biological mechanisms of neointimal proliferation and have become the mainstay of the interventional treatment of coronary atherosclerotic disease.11 However, the demonstrated efficacy of DES is balanced by the small but unpredictable risk of very late stent thrombosis thought to be due to delayed vascular healing resulting from either the initial antiproliferative effect (and associated late acquired incomplete stent apposition) or a hypersensitivity reaction to the drug, polymer coating, or their combination.12,13 Moreover, beyond the coronary vasculature, there has been a paucity of effective therapies to manage restenosis after intervention. In recent years, drug-coated balloons (DCBs) have emerged as a therapeutic alternative in the interventional field.14 With this technology, short-term transfer of antiproliferative drugs to the arterial wall is achieved without the requirement of an implanted drug delivery system, thus potentially reducing the untoward effects associated with polymer-based stent technologies. In small clinical randomized trials, paclitaxel-coated balloons have been shown to be …

Stent Graft versus Balloon Angioplasty for Failing Dialysis-Access Grafts

Conclusion: Revision of a venous anastomotic stenosis of a prosthetic dialysis access graft with a stent graft provides longer-term patency and freedom from repeat intervention than revision with standard balloon angioplasty. Summary: Secondary patency of hemodialysis grafts is at best 50% at 3 years. Many interventions are typically required to maintain dialysis-access graft patency. The authors sought to test the hypothesis that revision of venous anastomotic stenosis with stent grafts constructed with the same material as the dialysis-access graft itself would improve long-term patency compared with that provided by revision with balloon angioplasty alone. Theoretically, stent graft revision would prevent elastic recoil associated with balloon angioplasty alone and prevent intimal hyperplasia in-growth at the venous anastomosis, resulting in improved patency of the revised grafts. This was a prospective multicenter trial. There were 190 patients undergoing hemodialysis with dialysis-access grafts and a venous anastomosis stenosis that were randomly assigned to receive balloon angioplasty alone or balloon angioplasty plus placement of a stent graft at the site of the venous anastomotic lesion. Patency of the treatment area and patency of the entire vascular access graft were the primary end points. At 6 months, patency of the treatment area was greater in the stent graft group than in the balloon angioplasty group (51% vs 23%, P < .001). Six-month patency of the dialysis access circuit was improved in the stent graft group vs the balloon angioplasty group (38% vs. 20%, P = .008). Freedom from subsequent intervention at 6 months was also greater in the stent graft group than in the balloon angioplasty group (32% vs 16%, P = .03). Restenosis was greater in the balloon angioplasty group than in the stent graft group (78% vs 28%, P < .001). Other adverse events at 6 months were equivalent in the two treatment groups. Comment: There is still a need for dialysis-access grafts. Results of this study suggest stent grafts provide better patency in treating venous anastomotic strictures of dialysis-access grafts than that provided by balloon angioplasty alone. Although the results are statistically significant, there are details to be considered before declaring the results clinically significant. Grafts in this study were treated before actual thrombosis. Many access grafts do not come to revision until they have thrombosed, and it is controversial whether surveillance and treatment of patent, but not thrombosed dialysis grafts, actually results in overall prolongation of usable access. In addition, 6 months after revision with a stent graft, there is primary patency in only half the patients. Stent grafts are more expensive than balloon angioplasty alone. It is therefore unclear whether the increased patency at 6 months will translate into longer-term cost-effectiveness and whether an approach of graft surveillance with treatment with this technology of narrowed venous anastomotic areas discovered with surveillance will result in meaningful overall clinical benefit or cost savings.

Stent Graft versus Balloon Angioplasty for Failing Dialysis-Access Grafts

The leading cause of failure of a prosthetic arteriovenous hemodialysis-access graft is venous anastomotic stenosis. Balloon angioplasty, the first-line therapy, has a tendency to lead to subsequent recoil and restenosis; however, no other therapies have yet proved to be more effective. This study was designed to compare conventional balloon angioplasty with an expanded polytetrafluoroethylene endovascular stent graft for revision of venous anastomotic stenosis in failing hemodialysis grafts. We conducted a prospective, multicenter trial, randomly assigning 190 patients who were undergoing hemodialysis and who had a venous anastomotic stenosis to undergo either balloon angioplasty alone or balloon angioplasty plus placement of the stent graft. Primary end points included patency of the treatment area and patency of the entire vascular access circuit. At 6 months, the incidence of patency of the treatment area was significantly greater in the stent-graft group than in the balloon-angioplasty group (51% vs. 23%, P<0.001), as was the incidence of patency of the access circuit (38% vs. 20%, P=0.008). In addition, the incidence of freedom from subsequent interventions at 6 months was significantly greater in the stent-graft group than in the balloon-angioplasty group (32% vs. 16%, P=0.03 by the log-rank test and P=0.04 by the Wilcoxon rank-sum test). The incidence of binary restenosis at 6 months was greater in the balloon-angioplasty group than in the stent-graft group (78% vs. 28%, P<0.001). The incidences of adverse events at 6 months were equivalent in the two treatment groups, with the exception of restenosis, which occurred more frequently in the balloon-angioplasty group (P<0.001). In this study, percutaneous revision of venous anastomotic stenosis in patients with a prosthetic hemodialysis graft was improved with the use of a stent graft, which appears to provide longer-term and superior patency and freedom from repeat interventions than standard balloon angioplasty. (ClinicalTrials.gov number, NCT00678249.)