The role of the stent graft is emerging in the management of arteriovenous dialysis access. Physicians are incorporating this device in the management of three distinct problems--vein-graft anastomotic stenosis, pseudoaneurysm formation, and cephalic arch stenosis--with varying degrees of success. Indeed, a recent randomized, controlled trial to evaluate the role of angioplasty plus stent graft versus angioplasty alone for the management of stenosis at the vein-graft anastomosis led to the approval of the stent graft by the Food and Drug Administration; however, several elements of the management of stenosis at the vein-graft anastomosis/cephalic arch as well as the repair of pseudoaneurysms by stent graft remain controversial. The situation is further complicated and warrants a cost-to-benefit ratio analysis when the added cost of the device is appended to the procedure. In contrast to the controversies, angioplasty-induced complete vascular rupture is one situation in which a stent graft is indicated beyond any doubt. With recent conditional Food and Drug Administration approval, it is anticipated that the use of stent grafts might increase in our patients. In this context, it is critically important that nephrologists be familiar with the current controversies and consensus that surround the use of stent grafts for dialysis access. Just as therapeutic interventions are analyzed in other disciplines within nephrology, these experts must appraise the use of this device for dialysis access. This report presents an up-to-date synopsis on the use of the stent graft that would assist renal physicians in requesting or rejecting the device for the optimal management of their patient's vascular access dysfunction.

PURPOSE: To determine the clinical efficacy of stent-graft placement in dysfunctional autogenous hemodialysis fistulas. MATERIALS AND METHODS: Between September 2006 and June 2008, 24 Fluency Plus stent-grafts were inserted in 17 patients with failing autogenous hemodialysis fistulas (two radiocephalic, 12 brachiocephalic, and three brachiobasilic). Six fistulas were thrombosed at presentation. Indications for stent-graft insertion included 10 residual stenoses, six pseudoaneurysms, and one fistuloplasty-induced rupture. Fistula function before and after intervention was assessed with ultrasound dilution technique. RESULTS: The technical success rate was 100%, as were the anatomic and clinical success rates. Via Kaplan-Meier method, the primary access patency rates were 94.1% at 3 months (95% CI, 0.461-0.995) and 88.2% at 6 and 12 months (95% CI, 0.468-0.980). The primary lesion patency rate was 94.1%(95% CI, 0.650-0.992) at 3, 6, and 12 months. The secondary access patency rate had a point estimate of 100% at 3 months, and was 93.8%(95% CI, 0.632-0.991) at 6 and 12 months. Univariate analysis suggested that male sex and left-sided accesses were associated with a longer primary access patency rate (P =.02). The binary restenosis rate at 6 months was 5.9%. Mean transonic flow rates were 667.5 mL/min before intervention and 2,076.0 mL/min after intervention (P =.03, Wilcoxon signed-rank test). No patients were lost to follow-up. CONCLUSIONS: Stent-graft placement in dysfunctional autogenous hemodialysis fistulas is technically feasible and effective in preserving function and preventing access abandonment, with patency rates that exceed historical patency rates with angioplasty and/or uncovered stents.

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 (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). 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.) Copyright 2010 Massachusetts Medical Society.

Objectives: The aim of this study was to analyze the risk and consequences of venous rupture during angioplasty of malfunctioning hemodialysis grafts and fistulas. Background: Venous stenoses in the outflow limb of hemodialysis accesses often require ultra-high balloon pressure for optimal dilatation. Methods: Baseline characteristics and outcomes were analyzed for a consecutive series of patients treated between 1999 and 2008. Results: Venous rupture or perforation occurred in 11 of 1242 (0.9%) procedures. No patient with a rupture or perforation died or required emergency or urgent surgical repair. Two of 11 patients (18.2%) required transfusions, 8 of 11 patients (72.7%) required stenting, and 6 of 8 (75.0%) who needed stenting received covered stents to achieve hemostasis. Rupture led to access thrombosis within 30 days in 9 of 11 cases (82%). Multivariable logistical regression analysis suggested that using a balloon catheter more than 2 mm larger than the diameter of the hemodialysis access or using peripheral cutting balloons increased the risk of rupture or perforation. Conclusions: Rupture or perforation is a rare complication of treatment of malfunctioning hemodialysis grafts and fistulas. The complication may be managed with nonsurgical methods and might be avoided by optimal balloon selection and sizing.(c) 2009 Wiley-Liss, Inc.

We report the case of a 66-year-old female who presented with jaundice secondary to recurrent adenocarcinoma of the gallbladder and several common bile duct stones. Percutaneous papillary dilatation was planned to remove the common bile duct stones. Papilla was dilated through the percutaneous approach with an 8-mm peripheral cutting balloon instead of a standard balloon. All the stones were pushed successfully into the duodenum with a saline flush. No complications were encountered. Use of a peripheral cutting balloon for dilatation of the papilla seems to be safe and effective because it has the advantage of controlled incision and dilatation of the target at low pressures.

PURPOSE: To evaluate the safety and feasibility of cryoplasty as the initial balloon treatment for dialysis access venous stenoses. MATERIALS AND METHODS: Twenty patients with grafts (n = 18) or arteriovenous fistulas (n = 2) were enrolled in an institutional review board-approved prospective study. Patients with high venous dialysis pressures (n = 7), poor flow (n = 3), abnormal thrill (n = 3), nonmaturation (n = 2), poor clearance (n = 2), edema (n = 1), prolonged bleeding (n = 1), or recurrent clotting (n = 1) in the presence of stenoses >/= 50% were eligible. Mean stenosis measurement was 62.8%(range, 51%-82%). Mean lesion length was 2.57 cm (range, 0.4-5.7 cm). Device success required complete cryoplasty balloon expansion. Procedure success required anatomic success combined with a clinical or hemodynamic indicator of success. Primary circuit patency ended with any restenosis. Primary lesion patency ended with index lesion restenosis. RESULTS: The device success rate was 53%(nine of 17). The anatomic success rate after cryoplasty was 35%(seven of 20). Eighty percent of lesions (16 of 20) were treated with conventional percutaneous transluminal angioplasty (PTA) balloons after cryoplasty. The procedure success rate after supplemental PTA was 80%(16 of 20). The primary circuit patency rates were 82%(14 of 17) at 3 months and 19%(three of 16) at 6 months. The primary lesion patency rates were 88%(15 of 17) at 3 months and 25%(four of 16) at 6 months. All patients reported pain during cryoplasty, and the 16 who underwent supplemental PTA described cryoplasty as more painful than PTA. Cryoplasty-related complications included one case of transient spasm. CONCLUSIONS: Use of the PolarCath peripheral balloon catheter system as the initial balloon for dialysis access venous stenoses is safe but painful. Anatomic success rates after cryoplasty are low. Results of cryoplasty supplemented by PTA appear comparable to those of PTA alone.

PURPOSE: To compare the technical success, safety, and patency of cutting balloon angioplasty versus high-pressure balloon angioplasty in the treatment of resistant native hemodialysis fistula stenoses. MATERIALS AND METHODS: The authors retrospectively reviewed 1,220 percutaneous transluminal angioplasty procedures performed to treat dysfunctional native hemodialysis fistulas. Seventy patients with stenoses resistant to conventional balloon angioplasty (up to 24 atm) were included in this study: 35 patients underwent cutting balloon angioplasty from September 2003 through February 2005, and 35 patients underwent high-pressure balloon angioplasty from March 2005 through April 2006. Evaluation included technical success, complications, and postintervention patency rates up to 6 months. RESULTS: The technical success rates were similar between the cutting balloon (100%) and high-pressure balloon (97.1%) groups. After cutting balloon angioplasty, the primary lesion patency rates were 100%(35/35), 88.6%(31/35), and 71.4%(25/35) at 1 month, 3 months, and 6 months, respectively. After high-pressure balloon angioplasty, the primary lesion patency rates were 97.1%(34/35), 62.9%(22/35), and 42.9%(15/35) respectively. The primary lesion patency rates at 3 and 6 months were significantly better with cutting balloon angioplasty than with high-pressure balloon angioplasty (P =.018 and .009, respectively). There were no device-related complications in the cutting balloon group. Six device-related extravasations occurred in the high-pressure balloon group. CONCLUSIONS: The results of this retrospective study suggest that, for resistant stenoses in native hemodialysis fistulas, both high-pressure balloon and cutting balloon angioplasty are effective; however, cutting balloon angioplasty seems to provide more long-standing primary patency at 6-month follow-up.

OBJECTIVES: To evaluate the technical success, safety and patency of cutting balloon angioplasty for the treatment of resistant dialysis access stenoses. BACKGROUND: Cutting balloon angioplasty has been proposed to be useful in treating resistant dialysis access stenoses. However, they are based on experience with very limited cases and formal patency data is insufficient. METHODS: The author retrospectively reviewed 896 percutaneous transluminal angioplasty (PTA) procedures for the treatment of dysfunctional or thrombotic dialysis access. Thirty-seven of 623 patients with native fistulas and 23 of 273 patients with synthetic grafts had residual stenoses of more than 30% after conventional PTA at an inflation pressure of 24 atm for 60 sec. In these 60 patients, additional cutting balloon PTA was performed. RESULTS: The overall technical success rate was 96.7% and clinical success rate was 98.3%. Only one patient experienced mild local extravasation. The postintervention primary patency rates for native fistula group (N = 37) were 100%, 86.4%, and 67.5% at 1-month, 3-month, and 6-month; the postintervention primary patency rates for synthetic graft group (N = 23) were 87.0%, 60.9%, and 34.2% at 1-month, 3-month, and 6-month respectively. CONCLUSIONS: For resistant venous stenoses of dialysis access, cutting balloon PTA is effective, safe, and seems to provide comparative primary patency as suggested by guidelines.

The Kidney Dialysis Outcomes Quality Initiative guidelines and the Fistula First Initiative for vascular access have had a measurable impact on the incidence and prevalence of the type of access used to deliver hemodialysis in the United States. There has been a yearly increase in the placement of arteriovenous fistulas and an exponential increase in endovascular treatment of failing and immature fistulas. Undoubtedly, the predominant cause of fistula malfunction is stenosis within the access system. The stenotic lesions can occur anywhere within the access system from the arteries to the outflow and central veins. One of the relatively common sites for stenosis in patients with brachiocephalic fistulas is the cephalic arch region. While access stenoses at many other sites have been successfully treated with percutaneous balloon angioplasty, the results of this approach in the management of cephalic arch stenosis (CAS) have been rather disappointing. This has been in part due to multiple factors including the resistant nature of the stenosis, the development of early restenosis, as well as poor patency and high vein rupture rates. This article discusses the anatomy, postulated etiology and percutaneous interventions for the treatment of CAS. In addition, the report highlights surgical alternatives to the management of stenosis in this segment of the cephalic vein.

The use of totally implantable venous access devices in radiology may be associated with complications such as occlusion of the system (because of the high density of some contrast), infection (if the port is not handled in aseptic conditions, using proper barrier protections), and mechanical complications due to the high-pressure administration of contrast by automatic injectors (so-called power injector), including extravasation of contrast media into the soft tissues, subintimal venous or myocardial injection, or serious damage to the device itself (breakage of the external connections, dislocation of the non-coring needle, or breakage of the catheter). The last problem - i.e., the damage of the device from a power injection - is not an unjustified fear, but a reality. A warning by the US Food and Drug Administration of July 2004 reports around 250 complications of this kind, referring to both port and central venous catheters and peripherally inserted central catheter systems, which occurred over a period of several years; in all cases, the damage occurred during the injection of contrast material by means of power injectors for computed tomography or magnetic resonance imaging procedures. Though the risk associated with the use of ports in radiodiagnostics is thus clear, it has been suggested that administration of the contrast material via the port may have some advantage in terms of image quality, increased comfort for the patient, and maybe more accurate reproducibility of the patient's own follow-up exams. This contention needs to be supported by evidence. Also, since many cancer patients who need frequent computed tomography studies already have totally implantable systems, it would seem reasonable to try to define how and when such systems may safely be used. The purpose of this consensus statement is to define recommendations based on the best available evidence, for the safe use of implantable ports in radiodiagnostics.

A review of the issues involved in placement of Tunneled Dialysis Catheter with a suggested scheme for maximizing good catheter placement and function.

At the time of hemodialysis vascular access evaluation, many chronic kidney disease patients already have iatrogenic injury to their veins which impedes the surgical construction of an arteriovenous fistula (AVF). Achieving the important goal of a greater prevalence of arteriovenous fistulae in the US hemodialysis population will require identification of those patients prior to reaching end-stage renal disease and an educational and procedural system for preserving their veins.

To determine the efficacy of using stents and stent grafts for treatment of hemodialysis graft-related stenoses which have failed angioplasty. This retrospective study was composed of 51 patients with polytetrafluoroethylene hemodialysis grafts who underwent angioplasty of a graft-related stenosis but subsequently required insertion of a stent or stent graft. The study group included 40 patients with >30% residual stenosis and 11 patients with angioplasty-induced venous ruptures. The patient's medical records and radiology reports were reviewed. Patient demographics, indication for stent placement, and the type of stent were recorded. Stent patency was determined using Kaplan-Meier analysis. A total of 70 stents were used; most (57.7%) were deployed across the venous anastomosis. A variety of different types of stents and stent grafts were used including 26 SMART, 18 Viabahn, 13 aSpire, and 13 other stents. The technical success rate for insertion of the device was 100%. Following insertion of the device the primary patency of the vascular access was 81%, 70%, and 54% at 1, 3, and 6 months, respectively. The secondary patency of the vascular access was 89%, 82%, and 74% at 3, 6, and 12 months, respectively. The primary patency of the stent or stent graft was 96%, 93%, 87%, and 47% at 1, 3, 6, and 12 months, respectively. Stents and stent grafts are useful for salvaging failed angioplasty procedures and thereby maintaining patency of the hemodialysis graft. By inserting a stent, the resultant patency rates are similar to those following a successful angioplasty procedure. Importantly, the primary patency of the stent was substantially better than the primary patency of the entire vascular access.

Different types of complications may occur during a percutaneous vascular access procedure and the majority of these complications are caused by balloon angioplasty. These balloon angioplasty-induced complications include venous rupture, venous dissection, and the development of an acute pseudoaneurysm. Balloon tamponade is the traditional percutaneous technique for management of these complications. However, insertion of a stent or stent graft has become an increasingly popular method to quickly and effectively repair a venous injury. A stent or stent graft may provide a more effective and durable method to treat balloon angioplasty-induced complications. Unfortunately, there are few, if any, clinical studies to substantiate the advantages and cost-effectiveness of these devices and so their use remains controversial.

A procedure-related complication is an unanticipated adverse event that requires therapy. In order to analyze frequency and severity of complications in the process of quality assurance, it is useful to have a classification of complications, indicating the type and severity. The Clinical Practice Committee of American Society of Diagnostic and Interventional Nephrology has developed a Classification of Complications relating to Hemodialysis Vascular Access Procedures, based on the system first proposed by Beathard in 2006. In this system, the "type" refers to the procedure being performed or vessel entered, and the "grade" is based on the intensity of medical care needed to address the complication. This publication describes 10 Types and 4 Grades of complications.

PURPOSE: To compare postintervention patency rates after deployment of bare metal versus covered stents across the venous anastomosis of prosthetic arteriovenous (AV) grafts. METHODS: Review of our procedural database over a 6 year period revealed 377 procedures involving stent deployment in an AV access circuit. After applying strict inclusion criteria, our study group consisted of 61 stent deployments in 58 patients (median age 58 years, 25 men, 33 women) across the venous anastomosis of an upper extremity AV graft circuit that had never been previously stented. Both patent and thrombosed AV access circuits were retrospectively analyzed. Within the bare metal stent group, 20 of 32 AV grafts were thrombosed at initial presentation compared to 18 of 29 AV grafts in the covered stent group. RESULTS: Thirty-two bare metal stents and 29 covered stents were deployed across the venous anastomosis. The 3, 6, and 12 months primary access patency rates for bare metal stents were not significantly different than for covered stents: 50, 41, and 22 % compared to 59, 52, and 29 %, respectively (p = 0.21). The secondary patency rates were also not significantly different: 78, 78, and 68 % for bare metal stents compared to 76, 69, and 61 % for covered stents, respectively (p = 0.85). However, covered stents demonstrated a higher primary stent patency rate than bare metal stents: 100, 85, and 70 % compared to 75, 67, and 49 % at 3, 6, and 12 months (p < 0.01). CONCLUSION: The primary and secondary access patency rates after deployment of bare metal versus covered stents at the venous anastomosis were not significantly different. However, bare metal stents developed in-stent stenoses significantly sooner.

Abstract Purpose: 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). Methods: 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). Results: 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). Conclusion: PCB angioplasty improves patency after angioplasty of venous stenoses of failing vascular access used for dialysis.

Purpose: The mechanisms of venous stenosis in vascular access include vascular constriction and neointimal hyperplasia. One purpose of this study was to examine the properties of stenotic lesions in arteriovenous graft outflow veins and the association with the results of treatment using stent placement.Subjects and Methods. The study involved 46 patients who underwent stent placement to treat arteriovenous graft outflow vein stenosis. The properties of stenotic lesions before stent placement were observed by ultrasonography and were classified into three groups: vascular constriction types, neointimal proliferation types, and mixed types. Stent placement was performed when elastic recoil occurred or when restenosis occurred at the same site within three months. The primary patency results for each group were then compared. The primary endpoint included patency of the treatment area.Results. The primary patency rate of the treatment area at 6, 12, 18 and 24 months post-stent placement for the vascular constriction type was 100.0%, 92.3%, 84.6% and 75.2%, respectively. Those rates were 66.7%, 33.3%, 33.3% and 25.0% for the neointimal proliferation type, and 90.5%, 52.4%, 38.1% and 27.2% with the mixed type. The vascular constriction type displayed excellent primary patency rates after stent placement.Conclusions. It is possible to define the types of stenotic lesions for which stent therapy is effective through morphological diagnosis of those lesions using ultrasound tomography.

Purpose: Endovascular procedures have been increasingly used for salvage of failing vascular access with conflicting results. The aim of this study was to assess the mid-term patency and complication rates of angioplasty procedures performed in a single center for treatment of stenosis compromising vascular accesses. Methods: A prospective database of vascular accesses performed in 2006-2010 was investigated. The endovascular approach was applied following a standardized protocol by a dedicated team. A total of 531 consecutive procedures were reviewed (326 men; mean age 70.94 years). Patency rates were estimated using the Kaplan-Meier method. Results: There were 199 procedures for failing access: 135 were surgical and 64 angioplasties performed for anastomosis (n=27), venous (n=45) or arterial (n=7) stenosis. Immediate technical success of endovascular procedures was 95.3%(61/64); complication rate was 6.3%(4/64). Primary patency rates were 55% at six months, 49% at 12 months, and 21% at 24 months. In the concurrent group of 135 open procedures, primary patency rates were 80% at six months and 67% at 12 months (P=.002); nevertheless, at 24 months, patency was as low as 49%. Cost estimates for angioplasty revealed additional fees ranging from 411.34 to 446.34 Euro with respect to open surgical procedures. Conclusions: Most dysfunctional vascular accesses can be successfully and safely treated by the endovascular route. In spite of poor mid-term durability, the angioplasty balloon might be considered as a bridge, effective, and repeatable solution with reasonable costs to prolong access survival avoiding additional surgery. The failure rate in the mid-term for dysfunctional vascular access may also be high after surgical reintervention.

Purpose: Patency of mature vascular access for hemodialysis is mostly limited by the growing stenoses leading to acute access thrombosis. The therapy of choice is usually percutaneous balloon angioplasty (PTA). However, PTA injures the vessel wall and subsequent re-stenosis develops faster than de novo stenosis. Therefore, the key is in appropriate timing of PTA procedures - as late as possible but before access thrombosis develops. Ultrasonography combines the morphologic and functional access assessment, but the former is less precise than angiography. The aim of this study was to compare ultrasonographic and angiographic measuring of residual diameter as the additional criterion of significant stenoses used in our center. Methods: Residual diameter of significant stenoses was measured by B-mode ultrasonography three times in 20 patients. All the patients were indicated for angiography and the residual diameter of the stenoses was re-analyzed by this method. The repeatability of ultrasonographic residual diameter measurements and reproducibility in comparison to angiography were expressed by coefficients of variation (CV). Results: The residual diameter was 1.69 ± 0.05 mm by ultrasound and 1.65 ± 0.59 mm measured by angiography. In the ultrasound repeatability study, CV was 3.17 ± 2.76% and in the reproducibility study CV was 18.0 ± 15.6%. All the stenoses found to be significant by ultrasound were above 65% by angiography and PTA was performed. Conclusions: Ultrasonographic measurement of the residual diameter is stable in experienced hands and is well comparable to angiography results. These findings advocate residual diameter of 2.0 mm as the strong additional criterion of the significant stenoses, which can also be used in ultrasound surveillance of arteriovenous grafts.

OBJECTIVE: Most arteriovenous hemodialysis grafts fail ≤18 months after implantation, most commonly due to intimal hyperplasia at the venous anastomosis. This open prospective study compared balloon angioplasty vs nitinol stent placement in the treatment of venous anastomotic stenosis after thrombectomy of prosthetic brachial-axillary accesses. METHODS: Between February 2007 and December 2010, 61 patients with an initial thrombosis of a prosthetic brachial-axillary access were admitted to our hospital. Of these patients, 28 (46%), treated before June 2008, underwent thrombectomy plus balloon angioplasty of the venous anastomosis (group A), whereas the remaining 33 (54%) patients, who were treated after July 2008, underwent graft thrombectomy plus angioplasty with self-expanding nitinol stent placement (group B). Primary, primary-assisted, and secondary patency rates were calculated using Kaplan-Meier analysis and compared between the two groups with the log-rank test. RESULTS: Primary patency was 32% at 3 months, 24% at 6 months, and 14% at 12 months in group A, and the respective values were 85%, 63% and 49% in group B. Primary patency was significantly better in group B than in group A (P <.001; log-rank test). Cumulative median patency was 60 days in group A and 260 days in group B. Patient age, sex, comorbidities, graft material, and graft age did not have prognostic significance. Primary-assisted and secondary patency rates were significantly higher in group B. CONCLUSIONS: Graft thrombectomy plus angioplasty with self-expanding nitinol stent placement provides significantly higher patency rates compared with thrombectomy plus plain balloon angioplasty of the venous anastomosis.

Vascular access stenosis is a major complication in hemodialysis patients. We prospectively observed 50 patients in whom 50 nitinol shape-memory alloy-recoverable technology (SMART) stents were used as salvage therapy for recurrent peripheral venous stenosis. Twenty-five stents each were deployed in native arteriovenous fistula (AVF) and synthetic arteriovenous polyurethane graft (AVG) cases. Vascular access patency rates were calculated by Kaplan-Meier analysis. The primary patency rates in AVF versus AVG at 3, 6, and 12 months were 80.3% versus 75.6%, 64.9% versus 28.3%, and 32.3% versus 18.9%, respectively. The secondary patency rates in AVF versus AVG at 3, 6, and 12 months were 88.5% versus 75.5%, 82.6% versus 61.8%, and 74.4% versus 61.8%, respectively. Although there were no statistically significant difference in patency between AVF and AVG, AVG showed poor tendency in primary and secondary patency. The usefulness of SMART stents was limited in a short period of time in hemodialysis patients with recurrent vascular access stenosis.

BACKGROUND AND OBJECTIVES Dysfunction of arteriovenous fistulas (AVFs) and arteriovenous grafts (AVGs) contributes significantly to morbidity and hospitalization in the dialysis population. We evaluated the primary patency of AVFs following percutaneous transluminal angioplasty (PTA) in haemodialysis patients. SUBJECTS AND METHODS We performed 231 interventions in 118 patients with a mean age of 62.1±12.9 years. We performed 122 interventions in 53 AVG patients (44.9%), and 109 interventions in 65 AVF patients (55.1%). If there was thrombosis of the vascular access, urokinase was administered and/or thrombus aspiration was performed. The stent was inserted when balloon dilatation did not expand sufficiently or elastic recoil occurred. RESULTS For the 118 patients, the median patency time was 10.45±10.29 months at 92 months of follow-up. The primary patencies for stenotic AVFs at 6, 12, 24, 36, 48, and 60 months were 63.4%, 41.4%, 17.0%, 9.7%, 7.3%, and 2.4%, respectively. The primary patencies for AVGs at 6, 12, 24, and 36 months were 36.9%, 19.5%, 10.8%, 2.1%, respectively, and were obtained by means of the Kaplan-Meier analysis (log rank=6.42, p<0.05). The median patency time was 11.0 months and 4.45 months in the non-thrombus and thrombus groups, respectively. The complication rate was 1.73%(4/231); two cases of pseudoaneurysms and two cases of extravasation were detected. All therapy failures (5/231) occurred in thrombotic lesions of AVGs and were treated surgically. CONCLUSION PTA is an efficacious method for the correction of stenosis of AVFs for hemodialysis, thus prolonging the patency of the fistulas.

BACKGROUND:=0.004) and primary patency (83.1% versus 32.8%; P<0.001), satisfying the primary hypotheses. In the secondary evaluations,(1) the primary DES group exhibited superior clinical benefit compared with the PTA group (88.3% versus 75.8%; P<0.001),(2) the provisional DES group exhibited superior primary patency (89.9% versus 73.0%; P=0.01) and superior clinical benefit (90.5% and 72.3%, P=0.009) compared with the provisional BMS group, and (3) the stent fracture rate (both DES and BMS) was 0.9%(4/457). CONCLUSIONS:. Unique identifier: NCT00120406.

Covered stents or stent grafts are exciting new products with multiple applications for patients with vascular disease, including hemodialysis access-related complications. Although most of the current uses of stent grafts in these settings are "off-label"(ie, not approved by the US Food and Drug Administration) several studies are currently underway to provide the necessary data to support their application. It is clear that stent grafts provide a rapid, effective means for endovascular repair of ruptured access vessels. The commercially available devices and their current applications for treating access-related complications, including aneurysms/pseudoaneurysms, venous outflow stenoses, cephalic arch lesions, ruptures, and diffuse access stenoses, will be reviewed in this article. Available data are reported along with our current clinical practice and algorithms.