Use of the Wallstent in the venous system including hemodialysis-related stenoses

Eighteen patients with a total of 23 venous stenoses or occlusions were treated with the Wallstent. In 5 patients treated for malignant stenosis there was one primary failure due to insufficient stent expansion. The other 4 patients showed rapid relief of their inflow obstruction, all remaining asymptomatic despite later stent occlusion in 1 patient. Four patients were treated for benign postoperative stenoses of the iliac or femoral vein. All stents remained patent for a period of 6 weeks-58 months. Nine patients were treated for one or multiple stenoses along the venous outflow tract of hemodialysis fistulas. Of 14 lesions that were eventually stented, 12 are still patent after 3–27 months (mean 19). However, 10 secondary interventions (eight percutaneous transluminal angioplasty (PTA), two stents) and three additional stent procedures for new lesions were necessary. Although our experience is limited, we believe that patients with tumor compression or postoperative strictures of large veins benefit from treatment with stents. Stenting of venous outflow stenoses in hemodialysis fistulas can significantly prolong stent function, however, PTA should always be the first treatment of choice.     

Endovascular Treatment of Central Vein Stenoses and/or Occlusions in Hemodialysis Patients

Purpose: To report our experience and results with the endovascular treatment of central vein stenoses and occlusions in hemodialysis patients. Methods: Between October 1999 and August 2001 (22 months) we performed 22 interventional procedures in 14 hemodialysis patients (8 women, 6 men) ranging in age from 38 to 87 years (mean 76 years). The indication for intervention was stenosis (n = 10) or occlusion (n = 4) of a central vein in the upper arm used for dialysis in patients with arm swelling and/or shunt malfunction. All patients had a previous history of subclavian vein cannulation. There were six percutaneous transluminal angioplasties (PTAs) and eight primary stent placements and eight repeat interventions. Seven were for restenoses and one for early occlusion, with two secondary stent placements and six PTA of in-stent stenoses. In two patients a second stent was implanted. The mean follow-up was 8.5 months (range 1–19 months). All stents were self-expandable with diameters ranging from 9 to 16 mm. Results: All but one of the procedures was technically successful (95%, n = 21). The patient with an unsuccessful procedure died 1 month after the procedure, but the death was not procedure-related. During follow-up three patients died with a patent shunt and central vein, none of them in connection with the procedure. No complication occurred during the interventional procedures. One patient was lost to follow-up. The primary patency rate at 12 months was 43%, with a primary assisted patency rate of 83% and a secondary patency rate of 100% (n = 6). Conclusion: Central vein stenoses and occlusions are associated with previous subclavian vein cannulation. They are a serious problem in hemodialysis patients with a shunt on the same arm. Endovascular treatment is a suitable option for these patients.     

Placement of venous stents: clinical experience with a self-expanding prosthesis.

A self-expanding vascular prosthesis was used to treat 20 venous stenoses or occlusions in 13 patients. The lesions were caused by tumor (n = 5), postoperative fibrous scars (n = 2), and chronic hemodialysis fistulas (n = 13). Follow-up ranged between 6 weeks and 53 months (mean follow-up, 14.9 months). Acute occlusion occurred in two stents, one within a tumor stenosis and one in a dialysis shunt after 3 days and 2 days, respectively. Balloon angioplasty, thrombolysis, and aspiration in the first case and balloon angioplasty and thrombolysis in the second case successfully restored patency. Definite occlusion occurred in these two patients after 8 weeks and 5 months, respectively. Ten secondary interventions were performed in three patients with 10 restenoses who had stenotic arm veins in chronic hemodialysis at presentation. Five of seven patients who received treatment for stenoses associated with hemodialysis underwent successful kidney transplantation 5-27 months after placement of vascular stents. Both patients who received treatment for benign strictures had patent stents at follow-up examinations performed at 45 and 53 months, respectively. Four of five stents placed for malignant stenoses were patent at venography (n = 3) or autopsy (n = 1).     

Directional atherectomy treatment for hemodialysis access: early results.

The Simpson atherectomy device was used to treat 12 intragraft stenoses, six complete subclavian vein occlusions, and 14 venous outflow stenoses in 24 patients undergoing hemodialysis. Patients were followed up clinically and by means of venography at approximately 1, 3, 6, 9, and 12 months after treatment. Twenty-eight atherectomy specimens were examined histologically. Twenty-six (81%) of 32 lesions were treated with initial technical success. Including technical failures, seven (58%) of 12 intragraft stenoses are angiographically patent at a mean of 5.0 months and five (50%) of 10 are clinically patent at 6 months. Three (50%) of six subclavian veins are angiographically patent at a mean of 5.6 months, and four (67%) of six are clinically patent at 6 months. Three (21%) of 14 venous outflow stenoses are angiographically patent at a mean of 5.0 months and five (38%) of 13 are clinically patent at 6 months. Histologic examination showed neointimal fibromuscular hyperplasia in 26 of 28 lesions. When 30% or less angiographic residual stenosis is used as the criterion for initial technical success, directional atherectomy appears to be effective therapy for intragraft stenoses and, with balloon angioplasty, for some catheter insertion-related subclavian occlusions. Directional atherectomy appears to have a recurrence rate for venous outflow stenoses similar to that for balloon angioplasty when the same criterion is used.     

Using pullback pressure measurements to identify venous stenoses persisting after successful angioplasty in failing hemodialysis grafts

OBJECTIVE: We used pullback pressure measurements to identify venous stenoses persisting after angioplasty of failing hemodialysis grafts. MATERIALS AND METHODS: Fifty angioplasty procedures were performed in 32 patients with elevated venous pressures at dialysis. Grafts were initially evaluated on digital subtraction angiography, and all stenoses measuring greater than 50% on angiography underwent angioplasty. In successful cases (residual stenosis < 30%), pullback pressure measurements were obtained from the superior vena cava to the graft to identify hemodynamically significant (> 10 mm Hg) stenoses. These lesions were then treated with repeated angioplasty. RESULTS: Hemodynamically significant stenoses with a gradient range of 10-27 mm Hg (mean, 16 mm Hg) were found in nine (18%) of 50 procedures. All gradients occurred at sites of previous angioplasty. Repeated angioplasty of these stenoses performed with larger angioplasty balloons reduced gradients to less than 3 mm Hg in six stenoses and to 5 mm Hg in three stenoses. In this subgroup, primary patency was eight (89%) of nine stenoses at 1 month and 2 months and five (56%) of nine stenoses at 6 months. Using life table analysis, we found that primary patency of the entire population was 84% at 1 month, 66% at 2 months, and 47% at 6 months. The mean time between interventions was 6 months, and the thrombosis rate was 0.32 per year. CONCLUSION: Pullback pressure measurements are a useful adjunct to angiography to evaluate the hemodynamic results of angioplasty in patients with failing hemodialysis grafts.     

Strecker stent in stenotic hemodialysis Brescia-Cimino arteriovenous fistulas

Flexible tantalum stents (Strecker) were used as an adjunct to percutaneous transluminal angioplasty (PTA) in the treatment of stenotic arterial or venous limbs of Brescia-Cimino hemodialysis fistulas. The diagnostic procedure was performed using retrograde fistulography. After PTA with unsatisfactory results, stents were placed in 5 patients with significant residual stenoses and poor fistula function. Within the mean follow-up period of 6.4 months (range 3–10 months) all fistulas were functioning. We conclude that Strecker stent is useful in the treatment of stenotic hemodialysis arteriovenous fistulas as an adjunct to PTA.     

Comparison of cutting balloon versus high-pressure balloon angioplasty for resistant venous stenoses of native hemodialysis fistulas

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.     

Technical aspects and results of percutaneous transluminal angioplasty in Brescia-Cimino dialysis fistulas

Our experience with percutaneous transluminal angioplasty for treatment of stenoses and occlusions in surgically created arteriovenous fistulas (Brescia-Cimino) is reported. Methodological aspects are emphasized. Forty-nine PTAs were performed in 36 patients, in 3 combined with the use of a vascular metallic endoprosthesis (Wallstent). The initial success rates for stenoses and occlusions and occlusions were 91% and 77%, respectively. Long stenoses and occlusions (>4 cm) showed significantly worse initial results (55%) as compared to short ones (95%). Of the primarily successfully treated shunts, 90% are still functioning after a mean follow-up time of 8 months. The results indicate that PTA may replace surgical intervention as the primary method for treatment of insufficient flow for internal arteriovenous shunts, provided fresh thrombi are not the cause of the occlusion. Metallic endoprostheses and the use of atherectomy catheters were shown to be a valuable adjunct to classical PTA in selected cases.     

Stent Grafts for Central Venous Occlusive Disease in Patients with Ipsilateral Hemodialysis Access

PurposeTo assess long-term outcomes of stent grafts in patients with symptomatic central venous stenoses and occlusions ipsilateral to hemodialysis grafts or fistulas.Materials and MethodsThe study included 52 of 55 consecutive patients with symptomatic stenoses of the central veins draining upper limb dialysis access grafts or fistulas treated with stent grafts. Indications for stent grafts were poor angioplasty results, rapid recurrence, or total occlusion. Endpoints were lesion patency and access patency following intervention. Mean follow-up was 25 months with a median of 24 months and 1.25 additional procedures per patient year. Patency rates were calculated using Kaplan-Meier analysis.ResultsAll stent grafts were successfully deployed. The lesion patency rates at 6, 12, 24, and 36 months after intervention were 60%, 40%, 28%, and 28%. The access patency rates at 6, 12, 24, and 36 months after intervention were 96%, 94%, 85%, and 72%. There was one major complication and no minor complications. In 40 patients (77%), the internal jugular vein confluence was covered by the stent graft. In five patients, the dialysis circuits became occluded, with no clinical sequelae in four; one patient was lost to follow-up. The contralateral brachiocephalic vein was covered in three patients (6%), preventing contralateral access construction in one patient.ConclusionsCentral vein stent graft placement in patients with hemodialysis access is associated with prolonged access patency. Coverage of major vein confluences, which occurred in 83% of the patients in this series, can compromise future access and should be avoided whenever possible by careful technique.     

Salvage of nonmaturing native fistulas by using angioplasty

PURPOSE: To retrospectively review outcomes following angioplasty of nonmaturing autogenous hemodialysis fistulas. MATERIALS AND METHODS: Institutional review board exemption was received for this HIPAA-compliant retrospective study; informed consent was waived. During 48 months, 101 patients underwent fistulography for percutaneous salvage of nonmaturing native fistulas. Clinical and technical success, need for secondary interventions, and complications were recorded according to consensus definitions. Patency following angioplasty was estimated with the Kaplan-Meier technique. Patient age, sex, ethnicity, fistula age, fistula type, number of stenoses, maximal angioplastic balloon diameter used, and presence of palpable thrill following angioplasty were examined as predictors of primary patency of the fistula following intervention by using Cox proportional hazards model. RESULTS: Mean patient age was 58 years; 35% were women. Median time from fistula creation to fistulography was 2.5 months. Hemodynamically significant (>50%) stenoses were identified in 88% (89 of 101) of patients; angioplasty was attempted in 96% (85 of 89). Technical success was achieved in 92% (78 of 85) of fistulas following angioplasty; clinical success of normal hemodialysis with total access blood flow of more than 500 mL/min occurred following 88% (75 of 85) of angioplastic interventions. No major and two minor complications occurred. Mean primary unassisted patency at 3, 6, and 12 months was 60%+/-6% (95% confidence interval), 45%+/-6%, and 34%+/-6%, respectively. Additional angioplasty (n=12), stent placement (n=1), or thrombectomy (n=1) during subsequent interventions resulted in mean secondary patency at 3, 6, and 12 months of 82%+/-4%, 79%+/-5%, and 75%+/-6%, respectively. Patients without thrill following angioplasty were more than twice as likely to lose patency as patients with thrill (P=.035). No relationship was seen between primary patency and other predictors examined. CONCLUSION: Early fistulography enables identification of underlying areas of stenosis in nonmaturing fistulas, which can be safely and effectively treated with angioplasty. With continued surveillance and repeat interventions, functional patency can be sustained in the majority of fistulas.     

Role of percutaneous angioplasty in keeping vascular access for hemodialysis]

The stenoses of anastomosed vessels or of implantation grafts are among the most frequent causes of insufficiency of vascular hemodialysis accesses. Percutaneous angioplasty allows the interventional radiologist too to participate in the salvage of shunts. From 1985 to 1991, 46 patients underwent the procedure. Angioplasty could be performed in 43 of them, and had to be repeated in some cases because of either relapse or malfunctioning new vascular access. On the whole, 59 maneuvers were performed, and 96 stenoses treated, 71 in Brescia-Cimino fistulas and 25 in Gore-Tex prostheses. The optimized standard technique employs access through the efferent vein and a diagnostic evaluation after blocking the flow with an inflatable cuff; 2-3 distensions lasting 2-3 minutes are performed with a 3.5-4 mm x 20 mm balloon catheter for the anastomosis. One or more 15-20-minute distensions follow, with a 6-8 mm x 20-40 mm Zijlstra balloon catheter (Schneider) for the lesions in the efferent vein. Our initial success rate was 88.7% (55 of 62 procedures). Follow-up results at 3, 6, 12, 24 months proved that for this type of lesion, which is usually supported by fibrosis and endarterial hyperplasia, estimated relapse rates exceed 50% in the first year and are lower than 10% a year in the following years. Complications are quite rare and can be partly prevented if the correct indications are followed, overdistension is avoided and the proper material is used. On account of the good results it yields, of its relative simplicity and of the very low incidence of complications, angioplasty should be considered as the treatment of choice for stenoses and their relapses in vascular hemodialysis accesses. As for treatment protocol, angioplasty is not a procedure to occasionally replace surgery, but a therapeutic approach which can be repeated at regular time intervals and can prolong the life of hemodialysis fistulas, thus delaying surgical reconstruction.     

Combined laser and balloon angioplasty of venous obstructions in patients with insufficient hemodialysis access fistulas

In 19 patients with insufficient hemodialysis access fistulas combined laser and balloon angioplasty of two occlusions and 17 stenoses of the shunt vein was performed. In 13 of those 19 cases the procedure was preceded by balloon angioplasty, which was insufficient because of resistant subintimal fibrosis. After using the pulsed dye laser a complete dilatation was possible in all cases.The new method is a valuable addition to percutaneous interventional techniques in patients with shunt problems, and better long term results may be expected in selected cases. Offprint requests to: E. Gmelin     

Percutaneous transluminal rotational atherectomy in the treatment of peripheral vascular disease using a transluminal endatherectomy catheter (TEC): Initial results and angiographic follow-up

Purpose To evaluate the clinical results of percutaneous transluminal rotational atherectomy in the treatment of peripheral vascular disease. Methods Rotational atherectomy was performed in 39 patients aged 39–87 years (mean 66.6 years). A total of 71 lesions (43 stenoses and 28 occlusions) were treated in 40 limbs. Additional balloon angioplasty was required in 54% of lesions. Fifteen patients (37.5%) presented in Fontaine stage II, 10 patients (25%) in Fontaine stage III and 15 patients (37.5%) in Fontaine stage IV. Rotational atherectomy at 750 rpm was carried out over a 0.014-inch guidewire with continuous aspiration into a vacuum, bottle. Follow-up angiography and color flow Doppler examinations were performed in 22 patients (23 limbs) after a mean period of 6 months (range 2–14 months) Results There was one primary technical failure. In 36 of 40 lesions there was a good angiographic result with residual stenoses in less than 30%. In 70 lesions treated by rotational atherectomy, however, 54% showed residual stenoses of 30%–50% and these cases required additional balloon angioplasty. The mean ankle-brachial index improved significantly (p<0.001), from 0.49 before the procedure to 1.01 after the procedure. A single distal embolus, related to primary recanalization, occurred and there were two large inguinal hematomas. Cumulative clinical patency after 6 months was 83.8% and cumulative angiographic patency after 6 months was 79.1%. Conclusion Percutaneous rotational atherectomy is a promising approach for the treatment of chronic peripheral vascular disease. Further prospective, randomized studies are necessary to compare percutaneous transluminal angioplasty with this new technical approach.     

Percutaneous excimer-laser and excimer-laser-assisted angioplasty of the lower extremities: results of initial clinical trial

Percutaneous peripheral excimer-laser angioplasty at 308 nm was used for treatment of 30 patients with peripheral vascular disease. Twenty-eight patients underwent laser-assisted balloon angioplasty, and two patients underwent laser angioplasty alone. Acute angiographic and clinical success was achieved in 24 of 31 (77%) femoropopliteal stenoses and occlusions. Seven of nine (78%) stenoses, six of seven (86%) short (0-5 cm) occlusions, seven of eight (88%) medium-length (6-10 cm) occlusions, three of four (75%) long (11-15 cm) occlusions, and one of three (33%) extreme (greater than 15 cm) occlusions were successfully treated. Inability to treat total occlusions was in each case related to a failure to maintain coaxial position and subintimal passage of the fiber. These cases demonstrate the feasibility of safely performing percutaneous peripheral excimer-laser or excimer-laser-assisted angioplasty. The overall frequency of restenosis after a mean follow-up period of 9.1 months was 29%. The data suggest that these procedures may be useful for the treatment of peripheral vascular disease in selected patients.     

Stenoses in dialysis fistulas: treatment with percutaneous angioplasty

Percutaneous transluminal angioplasty (PTA) was performed on 30 stenotic lesions in 25 dialysis access fistulas. The fistulas were in 23 patients with a mean age of 53 years. Lesions were detected with angiography within a few days after poor flow or increased venous pressure was documented during dialysis. Twenty-two lesions were in patients with polytetrafluoroethylene graft fistulas, five were in patients with bovine carotid fistulas, and three were in patients with endogenous arteriovenous fistulas. There were 28 venous stenoses (20 at the anastomotic site and eight more proximally) and two arterial stenoses. The overall success rate was 80%, with a 6-month patency of 76% and a mean patency after PTA of 9.4 months. Among the venous lesions, the success was 100% for proximal lesions and 71% for anastomotic lesions. There were two technical failures, which required surgery for revision of the fistulas, and four self-limited hematomas. PTA is a safe and effective treatment for stenoses in dialysis fistulas, particularly for lesions remote from the anastomotic sites.     

Treatment of iliac artery stenoses with the Wallstent endoprosthesis

Sixteen symptomatic iliac artery stenoses and three occlusions in 16 patients were treated by the percutaneous implantation of Wallstent endoprostheses (Medinvent SA, Lausanne, Switzerland). The endoprosthesis consists of stainless steel monofilaments braided into a self-expanding cylinder. The indications for placement were restenosis after angioplasty (10 cases), failed arterial dilations (eight cases), and restenosis after endarterectomy (one case). The prostheses used had a mean diameter of 8 mm (range, 6-10 mm) and were placed in the external iliac (14 cases) and common iliac (five cases) arteries. The 16 stenoses were greater than 80%, and the three occlusions were longer than 7 cm. Mean length of the lesions treated was 7 cm (range, 4-14 cm). Three of the arteries thrombosed after treatment, one 2 days later and two in the month after implantation of the stent. On clinical and angiographic follow-up (mean, 16 months; range, 1-24 months) no symptoms or stenoses reappeared in the remaining 16 cases. Our experience in these cases suggests that implantation of a Wallstent endovascular prosthesis is a valuable technique for the treatment of external and common iliac artery stenoses.     

Prevention of Recurrent Central Venous Stenosis Using Endovascular Irradiation Following Stent Placement in Hemodialysis Patients

This study was done to evaluate the outcome after brachytherapy (BT) given to prevent restenosis after stent insertion for central venous stenosis in patients with ipsilateral hemodialysis arteriovenous fistulas (AVF). Angioplasty and stenting were performed on 9 primary central venous stenoses in 8 patients with AVF followed by BT, delivering Iridium-192 radiation using an afterloading technique. BT was also administered to three patients with five recurrent stenoses at the stent margins. There was no residual stenosis after angioplasty and stenting. Venographic follow-up (77-644 days, mean 272 days) showed no restenosis in seven primary stenoses. New strictures (45%-100%) developed at the stent margin in six veins (five patients). Angioplasty or stenting was performed for five margin stenoses in three patients, followed by a second BT. Residual stenosis before BT was 0-30%. In our venographic follow-up (140-329 days, mean 215 days), three restenoses occurred (35%-100%). All progressed to complete occlusion on later venographic follow-up irrespective of whether BT was given to the stent margin or not. The mean primary and assisted primary patency of the central veins were 359 days and 639 days, respectively. Endovascular irradiation with a noncentering source does not prolong the patency after angioplasty and stenting of central venous stenosis in hemodialysis patients.     

Balloon angioplasty of venous structures

Percutaneous transluminal angioplasty was attempted in 20 patients with stenoses of venous structures. It concerned one stenosis in a native subclavian vein, 12 stenoses in venous bypass grafts and 7 stenoses in hemodialysis-access fistulas. Primary results were excellent for the procedures in the native vein and the venous bypass grafts with success in all patients (13/13). In the arteriovenous fistulas for hemodialysis, dilatation of the venous stenoses was only possible in 5 out of 7 patients. The subclavian vein stenosis did not recur within a follow-up period of 3 years. Of the stenoses in the venous bypass grafts, two lesions reoccluded within one week and 6 lesions recurred within one year. Two of these lesions were successfully redilated so that 6 lesions remain patent with a follow-up of more than one year. Of the 5 successful dilatations in hemodialysis-access fistulas, two lesions recurred within 2 months. Only 3 veins are still accessible for hemodialysis. It is concluded that attempts at balloon dilatation of stenoses in venous bypass grafts or hemodialysis-access fistulas are meaningful in order to prolong the life of these surgical procedures. Recurrence of stenoses is however likely to occur within one or two years.     

Gadolinium-enhanced digital subtraction angiography of hemodialysis fistulas: a diagnostic and therapeutic approach

OBJECTIVE: The aim of our study was to evaluate the feasibility, safety, and potential role of the contrast agent gadoterate meglumine for digital subtraction angiography as a single diagnostic procedure or before percutaneous transluminal angioplasty of malfunctioning native dialysis fistulas. MATERIALS AND METHODS: Over a 20-month period, 23 patients (15 women, eight men) with an age range of 42-87 years (mean, 63 years) having end-stage renal insufficiency and with recent hemodialysis fistula surgical placement underwent gadoterate-enhanced digital subtraction angiography with a digital 1024 x 1024 matrix. Opacification was performed on the forearm, arm, and chest with the patient in the supine position using an injection (retrograde, n = 14; anterograde, n = 8; arterial, n = 1) of gadoterate meglumine into the perianastomotic fistula segment at a rate of 3 mL/sec for a total volume ranging from 24 to 32 mL. Percutaneous transluminal angioplasty was performed in three patients and required an additional 8 mL per procedure. Examinations were compared using a 3-step confidence scale and a two-radiologist agreement (Cohen's kappa statistic) for diagnostic and opacification quality. Tolerability was evaluated on the basis of serum creatinine levels and the development of complications. RESULTS: No impairment of renal function was found in the 15 patients who were not treated with hemodialysis. Serum creatinine level change varied from -11.9% to 11.6%. All studies were of diagnostic quality. The presence of stenosis (n = 14) or thrombosis (n = 3) in arteriovenous fistulas was shown with good interobserver agreement (kappa = 0.71-0.80) in relation to opacification quality (kappa = 0.59-0.84). No pain, neurologic complications, or allergiclike reactions occurred. Three percutaneous transluminal angioplasty procedures (brachiocephalic, n = 2; radiocephalic, n = 1) were successfully performed. CONCLUSION: Gadoterate-enhanced digital subtraction angiography is an effective and safe method to assess causes of malfunction of hemodialysis fistulas. It can also be used to plan and perform percutaneous transluminal angioplasty.     

Arterial stent placement with use of the Wallstent: midterm results of clinical experience

Self-expandable stents of the Wallstent type were used in 26 iliac and 15 femoropopliteal artery lesions of 31 patients to treat stenoses or occlusions. The indications were confined to complex lesions, including residual stenoses and dissections after percutaneous procedures or previous surgery in the iliac artery lesions, and long-segment (mean, 13.5 cm) occlusions with inadequate response to percutaneous recanalization in the femoropopliteal artery lesions. In the iliac artery group, after stent placement, 96% of the lesions were patent at a mean follow-up of 16 months (range, 6-30 months). In the femoropopliteal artery group, of 11 patients available for follow-up, only six had patent stents at 7-26 months (mean, 20 months). Four of these six patients required one to three secondary interventions. Self-expanding endoprostheses are of great value in complex iliac artery lesions where simple balloon dilation is insufficient. Stent placement for long femoral artery lesions should be performed with utmost reserve, and the extent of stent placement should be as short as possible.