SUPERA Interwoven Nitinol Stent Outcomes in Above-Knee IntErventions (SAKE) Study

PurposeTo report experience with the novel interwoven-wire self-expanding nitinol SUPERA stent (IDEV Technologies, Inc/Abbott Laboratories, Inc, Webster, Texas) for the treatment of severely diseased superficial femoral and popliteal arteries.Materials and MethodsConsecutive patients with severely diseased superficial femoral and popliteal arteries who received SUPERA stents (n = 80 patients [98 limbs]; mean age, 70.8 y; 80% male) were retrospectively identified. Patients were followed for an average of 14.3 months after intervention.ResultsTotal occlusions were present in 39% of the lesions, 21% had tissue loss, and 61% demonstrated calcification on fluoroscopy. Patients were prescribed dual antiplatelet therapy (aspirin and clopidogrel) for at least 30 days unless contraindicated, followed by aspirin alone indefinitely. The mean (± SD) lesion length was 143 mm (± 98). Based on need for clinical intervention, primary patency was 96.9% at 6 months and 85.8% at 12 months (Kaplan-Meier estimates). Assisted primary patency and secondary patency rates at 12 months were 96.8% and 100%, respectively. Ankle-brachial index increased from 0.60 at baseline to 0.83 at last follow-up (P < .001). No stent fractures were found by fluoroscopy inspection in 19 limbs (16 patients) that required reintervention.ConclusionsBased on experience with multiple operators at a single clinical center, the interwoven nitinol stent design provides a viable option for high-grade obstructive disease in the femoropopliteal artery.     

Percutaneous transluminal angioplasty (PTA) and venous stenting in hemodialysis patients with vascular access-related venous stenosis or occlusion

Aim of the studyTo present our experience with PTA and venous stenting in hemodialysis patients with vascular access (VA) related venous stenosis or occlusion.Patients – methodsWe studied retrospectively 22 hemodialysis patients with VA-related venous stenosis or occlusions that were treated with PTA and subsequent stenting. The following lesions were detected by digital subtraction venography: occlusion of the brachiocephalic and/or subclavian veins in four patients, stenosis (80–90%) of the same veins in 10 patients, stenosis (80–95%) of the axillary vein in four patients, brachial vein stenosis in two patients, and cephalic vein stenosis in two patients. The follow-up period ranged from 3 to 29 months (mean 15.4 ± 9.8 months). Primary and cumulative stent patency was recorded.ResultsTwenty-two primary venous PTA–stent implantation procedures were performed using 25 stents. The initial deployment of these 25 stents was technically successful, with complete opening (>80%) of the vein's lumen in all but one patient (95.4%). The patency of the vein immediately after the stenting procedure was greater than 90% in 13 patients, 80–90% in eight patients, and less than 40% in the case involving failure. Seventeen episodes of re-obstruction occurred in 13 patients (59%), and all were treated with the same PTA–stent procedures. At the end of the study period 47 stents had been placed in patients. The 3, 6, 12 and 24-month primary patency rates were 88.3%, 65.3%, 45.6% and 25.5%, respectively. Overall cumulative stent patency was 95.4% after 3 months, 79% after 6 months, 74% after 12 months, and 62.8% after 24 months.ConclusionPTA with primary venous stenting is an effective method for the treatment of VA-related stenosis or occlusion. However, repeat and sometimes multiple interventions are usually needed for the treatment of re-stenosis or re-occlusion episodes.     

Heparin-bonded,Expanded Polytetrafluoroethylene-lined Stent Graft in the Treatment of Femoropopliteal Artery Disease: 1-Year Results of the VIPER (Viabahn Endoprosthesis with Heparin Bioactive Surface in the Treatment of Superficial Femoral Artery Obstructive Disease) Trial

PurposeTo evaluate the performance of a heparin-bonded, expanded polytetrafluoroethylene (ePTFE)–lined nitinol endoprosthesis in the treatment of long-segment occlusive disease of the femoropopliteal artery (FPA) and to identify factors associated with loss of patency.Materials and MethodsIn a single-arm, prospective, 11-center study (VIPER [Gore Viabahn Endoprosthesis with Heparin Bioactive Surface in the Treatment of Superficial Femoral Artery Obstructive Disease] trial), 119 limbs (113 patients; 69 men; mean age, 67 y), including 88 with Rutherford category 3–5 disease and 72 with Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II) C or D lesions of the FPA, underwent stent graft implantation. The mean lesion length was 19 cm; 56% of lesions were occlusions. Follow-up evaluations included color duplex ultrasonography in all patients, with patency defined as a peak systolic velocity ratio< 2.5.ResultsAt 12 months, Rutherford category and ankle-brachial index (ABI) were significantly improved (mean category improvement, 2.4; ABI increased from 0.6±0.2 to 0.9±0.19; P<.0001). Primary and secondary patency rates were 73% and 92%. The primary patency for devices oversized<20% at the proximal landing zone was 88%, whereas the primary patency for devices oversized by>20% was 70% (P = .047). Primary patency was not significantly affected by device diameter (5 vs 6 vs 7 mm) or lesion length (≤20 cm vs>20 cm). The 30-day major adverse event rate was 0.8%.ConclusionsThe heparin-bonded, ePTFE/nitinol stent graft provided clinical improvement and a primary patency rate of 73% at 1 year in the treatment of long-segment FPA disease. Careful sizing of the device relative to vessel landing zones is essential for achieving optimal outcomes.     

Lower Extremity Venous Stent Placement: A Large Retrospective Single-Center Analysis

PurposeTo study short-term and long-term outcomes of lower extremity venous stents placed at a single center and to characterize changes in vein diameter achieved by stent placement.Materials and MethodsA database of all patients who received lower extremity venous stents between 1996 and 2018 revealed 1,094 stents were placed in 406 patients (172 men, 234 women; median age, 49 y) in 513 limbs, including patients with iliocaval stents (9.4% acute thrombosis, 65.3% chronic thrombosis, 25.3% nonthrombotic lesions). Primary, primary assisted, and secondary patency rates were assessed for lower extremity venous stents at 1, 3, and 5 years using Kaplan-Meier analyses and summary statistics. Subset analyses and Cox regression were performed to identify risk factors for patency loss. Vein diameters and Villalta scores before and up to 12 months after stent placement were compared. Complication and mortality rates were calculated.ResultsPrimary, primary assisted, and secondary patency rates at 5 years were 57.3%, 77.2%, and 80.9% by Kaplan-Meier methods and 78.6%, 90.3%, and 92.8% by summary statistics. Median follow-up was 199 days (interquartile range, 35.2–712.0 d). Patency rates for the subset of patients (n = 46) with ≥ 5 years of follow-up (mean ± SD 9.1 y ± 3.4) were nearly identical to cohort patency rates at 5 years. Patients with inferior vena cava stent placement (hazard ratio 2.11, P < .0001) or acute thrombosis (hazard ratio 3.65, P < .0001) during the index procedure had significantly increased risk of losing primary patency status. Vein diameters were significantly greater after stent placement. There were no instances of stent fracture, migration, or structural deformities. In patients with chronic deep vein thrombosis, Villalta scores significantly decreased after stent placement (from 15.7 to 7.4, P < .0001). Perioperative mortality was < 1%, and major perioperative complication rate was 3.7%.ConclusionsCavo-ilio-femoral stent placement for venous occlusive disease achieves improvement of vein disease severity scores, increase in treated vein diameters, and satisfactory long-term patency rates.     

Five-Year Outcomes of the Bioresorbable Peripheral Remedy Stent in the Treatment of Iliac Artery Disease

PurposeTo evaluate the 5-year performance of a bioresorbable vascular scaffold, the Remedy stent, for the treatment of iliac artery atherosclerotic disease.Materials and MethodsThis prospective, multicenter, single-arm clinical study evaluated 97 patients (97 lesions) with symptomatic TransAtlantic Inter-Society Consensus II A/B iliac artery lesions for 5 years after stent placement. The primary efficacy end point was 12-month primary patency compared with the prespecified standard derived from historical data with metallic stents, and the primary safety end point was the occurrence of major adverse clinical events within 5 years. All angiographic and computed tomography angiographic findings were evaluated by an independent core laboratory for quantitative vessel analysis.ResultsThe 12-month primary patency rate was 88.6% (95% CI, 80.1%–94.4%), which was lower than the prespecified standard. No significant difference was noted between the diameter stenosis at 9 and 12 months. There were no device- or procedure-related deaths, major amputation, or distal embolization during the follow-up period. The ankle-brachial index maintained significant improvement through the 5-year period compared with that at baseline. The Kaplan–Meier estimates of freedom from target lesion revascularization (TLR), major adverse cardiovascular events, and major adverse cardiovascular and limb events were 95.8%, 91.7%, and 87.5% at 12 months and 85.4%, 72.1%, and 62.5% at 5 years, respectively.ConclusionsThe 5-year follow-up outcomes, including freedom from TLR, of the Remedy stent in iliac artery lesions were satisfactory, with a good safety profile. Nevertheless, the 12-month primary patency did not meet the expected standard compared with that of contemporary metallic stents.     

Use of the Gore Tigris Vascular Stent in Advanced Femoropopliteal Peripheral Arterial Disease

Purpose

To prospectively evaluate the safety and efficacy of using the Tigris vascular stent (Gore, Flagstaff, Arizona) alone or in combination with the Viabahn stent (Gore) for revascularizing femoropopliteal Trans-Atlantic Intersociety Consensus (TASC) type B–D lesions with varying degrees of calcification.

Endovascular placement of self-expanding nitinol coil stents for the treatment of femoropopliteal obstructive disease

PURPOSE: To report on a prospective two-center study to evaluate safety and effectiveness of a self-expanding nitinol coil stent in patients with femoropopliteal obstructive disease. MATERIALS AND METHODS: The IntraCoil nitinol stent was used in 37 patients (28 men and nine women; mean age, 62.4 y plus minus 10.7; range, 43-81 y) presenting with high-grade stenoses (n = 23) or short (<3 cm) occlusions (n = 17) of the superficial femoral artery (SFA; n = 33) or popliteal artery (n = 4). Indications for stent placement were significant residual stenosis (>30%) or dissection after angioplasty. Follow-up evaluations with measurement of the Doppler ankle-brachial index (ABI), assessment of Rutherford clinical stage, and color-coded duplex sonography were performed at discharge and 1, 3, 6, 12, and 18 months thereafter. Primary endpoints of the study were immediate technical and clinical success and 1-year patency. RESULTS: Initial technical success was achieved in all patients. In 10 patients (27%), more than one 40-mm-long device had to be implanted for total lesion coverage; in three patients (8.1%), stents were placed in two separate segments of the SFA simultaneously. The total number of stents deployed was 50. Stent placement induced an initial improvement of the ABI from 0.54 plus minus 0.2 to 0.92 plus minus 0.11 (P <.01). Follow-up data for 12 months after treatment are available for 29 of 37 patients (78.4%); mean follow-up is 15.6 months (range, 1-26 mo). Primary patency rates at 6 and 12 months were 97.1% (SE = 2.9) and 86.2% (SE = 6.5). The primary assisted patency rate was 100% at 12 months. CONCLUSION: Endovascular placement of the IntraCoil self-expanding nitinol coil stent for salvage of failed angioplasty in patients with femoropopliteal obstructive disease is an effective and safe procedure with promising mid-term results.     

Three-Year Efficacy and Safety of the Misago Peripheral Stent for Superficial Femoral Artery Disease: Final Results from the OSPREY Trial

PurposeThis study evaluated the long-term outcomes of the Misago peripheral stent trial (Terumo) for atherosclerotic lesions in the superficial femoral artery (SFA) in patients with claudication.Materials and MethodsThis was a prospective multicenter, single-arm, clinical trial of primary stent placement for de novo cases of SFA disease conducted in the United States and Asia. The primary endpoint was freedom from clinically driven target lesion revascularization (CD-TLR) at 36 months. Secondary outcomes were ankle-brachial index (ABI), Rutherford score, Walking Impairment Questionnaire (WIQ), a quality of life survey, and rate of device fracture.ResultsA total of 276 patients (64.4% male; mean age, 69.3 ± 10.1 years) were enrolled. Freedom from CD-TLR was 78.5% (95% confidence interval [CI], 73.0%–83.0%) at 24 months and 75.4% (95% CI, 69.6%–80.2%) at 36 months. Baseline ABI was 0.7 ± 0.1 and 0.98 ± 0.20 (P < .001) at 30 days after the procedure. Baseline Rutherford score was 3.6 ± 0.6 and 1.6 ± 1.0 30 at 30 days after the procedure (P < .001). Mean (and changed) ABI and Rutherford score at 36 months compared to day 30 after the procedure were, respectively, 0.91 (−0.1 ± 0.2) and 1.5 (−0.2 ± 1.1). WIQ score at baseline was 21.49 ± 26.30 and 50.51 ± 38.49 at 30 days after the procedure ( P < .001). The mean WIQ score at 2 years was 46.65 ± 37.31 (P = .12). Stent fracture rate at 36 months was 2.0% (4 of 202 patients).ConclusionsOSPREY (Occlusive-Stenotic Peripheral Artery Revascularization Study) 36-month data demonstrated persistent freedom from CD-TLR and sustained improvement in ABI and Rutherford score with primary stent placement for SFA lesions.     

Self-expanding nitinol stents in the femoropopliteal segment: technique and mid-term results

The purpose of this study was to evaluate the safety and efficacy of self-expanding SMART nitinol stents in patients with chronic limb ischemia (CLI) demonstrating Type B or C TransAtlantic Inter-Society Consensus (TASC) lesions in the femoropopliteal (FP) arterial segment. There were 137 lower limbs in 122 patients with chronic limb ischemia, secondary to TASC A (n = 12) or TASC B,C (n = 125) lesions in the FP artery were treated with Cordis SMART self-expanding nitinol stents. Hemodynamic stent failure occurred with the presence of a greater than 50% stenosis within the stented segment, measured by standard Duplex velocity criteria, obtained at various postintervention intervals. The hemodynamic primary stent patency was calculated by life-table methods from the time of intervention, uninterrupted by hemodynamic stent failure. The mean lesion length was 12.2 cm (range, 4 to 28 cm). The technical success was 98%. Within the follow-up period (mean, 302 days), 24 limbs were diagnosed with hemodynamic stent failure. The hemodynamic primary stent patency rates were 92%, 76%, 66%, and 60% at 6, 12, 18, and 24-months, respectively. These data provide objective evidence that endovascular treatment of FP TASC A, B and C lesions using self-expanding nitinol SMART stents in patients with chronic limb ischemia provides favorable safety and durability outcomes. Further investigation is warranted.     

Prospective,Multicenter Clinical Study of the Covera Vascular Covered Stent in the Treatment of Stenosis at the Graft-Vein Anastomosis of Dysfunctional Hemodialysis Access Grafts

PurposeTo study the use of the self-expanding Covera covered stent for the treatment of stenotic lesions at the venous anastomosis of hemodialysis arteriovenous grafts (AVGs).Materials and MethodsA total of 110 patients with AVG venous anastomotic stenosis of ≥50% and access dysfunction were treated at 14 centers in the United States using percutaneous transluminal angioplasty followed by covered stent placement. The primary end points were 30-day safety and 6-month target lesion primary patency (TLPP). The secondary measures included access circuit primary patency, circuit cumulative patency, and the number of reinterventions through 24 months.ResultsFreedom from a primary safety event at 30 days was 96.4% while the 6-month TLPP rate was 70.3%. Seventy-five patients completed 24-month follow-up (68.2%). The TLPP rates were 54.2% at 365 days and 36.9% at 730 days while the access circuit primary patency rates were 16.7% at 365 days and 7.8% at 730 days (Kaplan-Meier analysis). The access circuit cumulative patency rates were 85.4% at 12 months and 73.6% at 24 months. The number of reinterventions to maintain the patency of the access circuit was 3.6 ± 3.1 at 24 months (1.6 ± 1.9 at the target lesion).ConclusionsUse of the Covera covered stent for hemodialysis graft-vein anastomotic stenosis provided a safe treatment option with a TLPP rate of 70.3% at 6 months and TLPP and cumulative access circuit patency rates of 36.9% and 73.6% at 2 years.     

Evaluating Patency Rates of an Ultralow-Porosity Expanded Polytetrafluoroethylene Covered Stent in the Treatment of Venous Stenosis in Arteriovenous Dialysis Circuits

PurposeTo evaluate the efficacy of an ultralow-porosity expanded polytetrafluoroethylene (ePTFE) covered stent in the treatment of autogenous arteriovenous fistula (AVF) and prosthetic arteriovenous graft (AVG) venous outflow stenoses.Materials and MethodsClinical and angiographic outcomes of 20 consecutive patients with arteriovenous dialysis circuits treated with the endoprosthesis were reviewed following institutional review board approval. Patients were followed routinely at 2 months and 6 months after stent placement, or earlier if clinically warranted. The primary endpoint was 2- and 6-month primary treatment area patency. Secondary endpoints included primary circuit patency, primary assisted patency, and secondary patency.ResultsEleven patients with AVFs and nine patients with AVGs were treated successfully with the covered stent. Primary treatment area patency rates were 85% ± 16 at both 2 months and 6 months. Primary circuit patency rates were was 65% ± 21 and 45% ± 22, respectively; primary assisted patency rates were 90% ± 13 and 85% ± 16, respectively; and secondary patency rates were 100% and 90% ± 13, respectively. Of the three cases of lost primary treatment area patency, two developed thrombosis and one developed recurrent stenosis. No significant differences were found between patients with AVFs and AVGs.ConclusionsData from this preliminary study suggests that the ultralow-porosity ePTFE covered stent may be a clinically viable option for treatment of venous outflow stenoses in arteriovenous vascular access circuits.     

Use of a New Hybrid Heparin-Bonded Nitinol Ring Stent in the Popliteal Artery: Procedural and Mid-term Clinical and Anatomical Outcomes

Purpose

To report the immediate and mid-term clinical and anatomical outcomes of a novel, hybrid, heparin-bonded, nitinol ring stent (TIGRIS; Gore Medical) when used for the treatment of lesions located in the popliteal artery.

Materials and Methods

This was a prospective single-centre registry. Patients eligible for inclusion were individuals suffering from symptomatic popliteal arterial occlusive disease (Rutherford–Becker stage 3–6; P1–P3 segments) and treated with placement of the TIGRIS stent(s). Patients were prospectively scheduled for clinical review and duplex ultrasound follow-up after 6 and 12 months. Outcome measures included immediate technical success, primary vessel patency, in-stent binary restenosis (evaluable by Duplex at 50 % threshold; PSVR > 2.0), freedom from target lesion revascularization (TLR) and amputation-free survival (AFS) estimated by Kaplan–Meier (K–M) survival analysis. Cox proportional-hazards regression analysis was also performed to adjust for confounders and search for independent predictors of outcomes.

Results

From August 2012 to March 2014, a total of 54 popliteal TIGRIS stents were implanted in 50 limbs of 48 patients (27 men and 21 women; mean age 76.0 ± 1.7 years). Median Rutherford–Becker stage was five at baseline and 37/50 (74.0 %) were chronic total occlusions. Technical success was achieved in all cases (100 %). Stented lesion length was 114.2 ± 36.9 mm (range 6–20 cm). Median follow-up was 11.8 ± 0.8 months. After 12 months, primary patency of the TIGRIS stent was 69.5 ± 10.2 % with an 86.1 ± 5.9 % freedom from TLR and 87 ± 5.0 % AFS (K–M estimates).

Conclusion

The TIGRIS hybrid heparin-bonded nitinol ring stent is a safe and effective endovascular option for complex occlusive disease of the popliteal artery.

     

Combined Antegrade Femoral Artery and Retrograde Popliteal Artery Recanalization for Chronic Occlusions of the Superficial Femoral Artery

PurposeTo evaluate the efficacy and safety of a dual femoral–popliteal approach in the supine position after failed antegrade recanalization attempts in chronic total occlusion (CTO) of the superficial femoral artery (SFA).Materials and MethodsFrom May 2011 to October 2012, 21 patients underwent dual femoral–popliteal recanalization for CTO of the SFA, with a mean lesion length of 87.4 mm ± 5.8. When contralateral antegrade recanalization of SFA occlusions via the common femoral artery could not be achieved, the occlusions were intrainterventionally accessed by retrograde approach via the popliteal artery, which was punctured anteriorly with gently flexed knee and crus extorsion. When the SFA had been recanalized, further angioplasty and stent placement procedures were completed via the femoral artery.ResultsA technical success rate of 100% (entailing puncture of the popliteal artery and SFA recanalization) was achieved, and no hemorrhage, hematoma, pseudoaneurysm, arteriovenous fistula, or other complications developed. During a mean follow-up of 9.8 months ± 1.5, claudication severity, rest pain, and toe ulcers improved significantly. The pulse of the distal arteries, as well as the filling of the veins, could be distinctly felt. Ankle-brachial index changed from 0.48 ± 0.17 to 0.84 ± 0.11 at 1 year after intervention (P < .001), and patency rates at 1, 6, and 12 months after interventions were 100%, 80%, and 42%, respectively.ConclusionsA dual femoral–popliteal approach in the supine position is an alternative backup option after failed attempts at the antegrade approach for patients with proximal barriers in CTO or lesions with major extending collateral vessels.     

Angioplasty of the pelvic and femoral arteries in PAOD: Results and review of the literature

Purpose

Evaluation of percutaneous recanalization of obstructed iliac as well as superficial femoral arteries (SFAs) in patients with peripheral arterial obstructive disease (PAOD).

Material and methods

The data of 195 consecutive patients with 285 obstructions of the common and or external iliac artery as well as the data of 452 consecutive patients with 602 long occlusions (length > 5 cm) of the SFA were retrospectively analyzed. The lesions were either treated with percutaneous transluminal angioplasty (PTA) or Excimer laser assisted percutaneous transluminal angioplasty (LPTA). Overall 316 stents were implanted (Nitinol stents: 136; stainless steel stents: 180) in the iliac artery and 669 stents were implanted (Nitinol stents: 311; Easy Wallstents: 358) in the SFA. The follow-up period was 36-65 months (mean 46.98 ± 7.11 months) postinterventionally using clinical examination, ABI calculation, and color-coded duplex sonography. Patency rates were calculated on the basis of the Kaplan-Meier analysis.

Results

The overall primary technical success rate was 97.89% for the iliac arteries and 92.35% for the SFA. Minor complications (hematoma, distal emboli and vessel dissection) were documented in 11.79% for the iliac arteries and 7.97% for the SFA. The primary patency rate was 90.3% for the iliac and 52.8% for the SFA after 4 years. The secondary patency rate was 96.84% for the iliac and 77.8% for the SFA after 4 years.

Conclusion

Percutaneous recanalization of iliac and superficial femoral artery obstructions is a safe and effective technique for the treatment of patients with PAOD. By consequent clinical monitoring high secondary patency rates can be achieved. The use of a stents seems to result in higher patency rate especially in the SFA when compared to the literature in long-term follow-up.     

Percutaneous Metallic Stent Placement in Patients with Cancer Recurrence at Bilioenterostomy Site

PurposeTo investigate the outcomes of percutaneous metallic stent placement in patients with malignant bilioenterostomy obstruction and to assess the risk factors influencing stent patency.Materials and MethodsFrom August 2008 to January 2012, 53 patients with malignant bilioenterostomy obstructions were treated with percutaneous placement of biliary metallic stents; this included expanded polytetrafluoroethylene (ePTFE)–covered stent placement in 36 patients and uncovered stent placement in 17 patients.ResultsA total of 75 stents were successfully placed in 53 patients. No major complications occurred in any patients, and minor complications occurred in nine patients (17%). The mean serum bilirubin level, which was 3.6 mg/dL ± 0.7 before drainage, decreased significantly to 2.5 mg/dL ± 0.4 at 1 month after stent placement (P = .041). Successful internal drainage was achieved in 44 of the 53 patients (83%). Kaplan–Meier analysis showed a median overall survival time of 145 days (95% confidence interval, 100–190 d), a median stent patency time of 313 days (95% confidence interval, 46–580 d), and cumulative stent patency rates at 1, 3, 6, 9, and 12 months of 91%, 75%, 64%, 56%, and 45%, respectively. Multivariate Cox regression analysis showed that the use of uncovered stents (odds ratio, 2.924; P = .033) was the only significant independent factor associated with stent occlusion.ConclusionsPercutaneous metallic stent placement is a safe and effective method for the treatment of patients with malignant bilioenterostomy obstruction. Moreover, as uncovered stent placement is the only significant independent factor associated with stent occlusion, ePTFE-covered stent placement is preferable in these patients.     

Midterm and Long-Term Outcomes following Dedicated Endovenous Nitinol Stent Placement for Symptomatic Iliofemoral Venous Obstruction: Three- to 5-Year Results of the VIRTUS Study

PurposeTo assess the midterm patency and long-term safety of placement of a dedicated venous stent (Vici Venous Stent System) for the treatment of venous lesions of the iliofemoral outflow tract.Materials and MethodsPatients with unilateral obstructive disease of the iliofemoral veins and a Clinical, Etiological, Anatomical, Pathophysiological class of 3 or higher or a Venous Clinical Severity Score of 2 or greater were enrolled in this prospective, multicenter, single-arm study at 23 sites in the United States and Europe. The patients were followed up for 36 months after the index procedure for the assessment of patency and up to 60 months for the assessment of safety. The clinical outcomes in 11 patients with a stent fracture were assessed.ResultsA total of 200 patients enrolled in 2 cohorts (ie, feasibility cohort, n = 30; pivotal cohort, n = 170) were combined for this analysis. The overall 36-month primary patency rate was 71.7% (86/120), and the 36-month primary patency rate was 96.4% (27/28) for the nonthrombotic group and 64.1% (59/92) for the postthrombotic group. The freedom from major adverse events was 81.2% (53/65) through 60 months. The 60-month Kaplan-Meier estimate of freedom from target vessel revascularization (TVR) was 84.3%. In 9 of the 11 patients who had a stent fracture (1 patient with nonthrombotic etiology and 10 patients with postthrombotic etiology) identified at 12 months, the stents extended into the common femoral vein. The TVR rates and clinical outcomes were similar between patients with and without a stent fracture.ConclusionsThe results of the VIRTUS study demonstrated good midterm patency and long-term safety following the placement of a dedicated venous stent for iliofemoral obstruction.     

Flexible tantalum stents for the treatment of renovascular hypertension: a 10-year experience

The aim of this study was to determine long-term success of flexible tantalum stents for the treatment of ostial and truncal renal artery stenosis. Since 1989, flexible tantalum stents (type Strecker) were implanted in 34 patients (36 arteries, 25 ostial lesions, 11 truncal lesions) with uncontrollable renovascular hypertension, 9 of them in association with renal insufficiency. Stents were placed unilaterally in 32 patients, and bilaterally in 2 patients for the treatment of renal artery stenosis. Thirty-five of 36 lesions were atherosclerotic, including 5 recurrencies after previous percutaneous transluminal renal angioplasty (PTRA). One patient had Takayasu arteritis. Stents were implanted after unsuccessful PTRA of 11 truncal and 23 ostial lesions, and as a primary procedure in 2 ostial lesions. Follow-up examinations included blood pressure measurement, determination of serum creatinine level, color duplex sonography, or angiography. The technical success rate was 92 %. Technical failure included incorrect stent placement (1 of 36 lesions, 2.8 %), and stent dislocation (2 of 36 lesions, 5.6 %), and two stents were retrieved percutaneously. In one case of Takayasu arteritis, residual stenosis of 40 % was observed. After technically successful stent placement, 77 % of patients became normotensive with or without medication. In the remaining patients there was partial improvement with blood pressure between 140 and 180 mmHg. Renal function improved in 76 % of patients (completely in 3 of 8, 38 %; and partially in 3 of 8, 38 %). Primary patency rate including all stented lesions and initial technical failures was 82.4 % ± 6.8 (1 year) and 82.4 % ± 9.2 (3 years). After technically successful stent placement, patency rates were 89.9 ± 5.6 % (1 year), and 89.9 ± 7.6 % (3 years). For ostial lesions, primary patency rate was 87.9 ± 6.7 % (1 year) and 87.9 ± 9.2 % (3 years). Placement of flexible tantalum stents in renal arteries is technically demanding, especially in ostial lesions. Once placed successfully, stent patency rate is excellent. Received: 8 December 1999; Accepted: 23 February 2000     

Early Results with the Use of Heparin-bonded Stent Graft to Rescue Failed Angioplasty of Chronic Femoropopliteal Occlusive Lesions: TASC D Lesions Have a Poor Outcome

Purpose

To evaluate early patency rate of the heparin-bonded stent grafts in atherosclerotic long femoropopliteal occlusive disease, and to identify factors that affect outcome.

Methods

Heparin-bonded Viabahn stent grafts were placed in 33 limbs in 33 patients during 2009–2010. The stents were deployed to rescue failed conventional balloon angioplasty. Mean age was 69 (range 44–88) years, and 67?% (22 of 33) were men. Most procedures (21 of 33, 64?%) were performed for critical limb ischemia (33?% for rest pain, 30?% tissue loss). Kaplan–Meier plots and Cox regression analysis were used to identify significant risk factors.

Results

The average length of lesions treated was 25?±?10?cm, and they were predominantly TASC (Transatlantic Intersociety Consensus) D (n?=?13) and C (n?=?17) lesions. The median primary patency was 5.0?months (95?% confidence interval 1.22–8.77). The mean secondary patency was 8.6?months (95?% confidence interval 6.82–10.42). Subsequently, 4 patients underwent bypass surgery and 5 patients underwent major amputation. One patient died. There were 5 in-stent or edge-stent stenoses. Cox multivariate regression analysis identified TASC D lesions to be a significant risk factor for early occlusion (p?=?0.035).

Conclusion

TASC D lesions of femoropopliteal occlusions have poor patency rates with the use of heparin-bonded stent grafts after failed conventional angioplasty. Alternative options should be considered for these patients.     

Stent Diameter,Not Cephalic Arch Anatomy,Predicts Stent Graft Patency in Cephalic Arch Stenosis

PurposeTo investigate the relationship between anatomic factors and primary patency of brachiocephalic arteriovenous fistulae (AVFs) after stent graft (SG) placement for cephalic arch stenosis (CAS).Materials and MethodsThis retrospective study reviewed all cephalic arch SGs placed in brachiocephalic AVFs in a tertiary academic medical center between 2014 and 2017. Sixty-three patients were included in the study. The mean patient age at the time of SG placement was 62.6 years ± 19, and the mean patient follow-up was 1,994 days ± 353. A cohort of patients (n = 31) who underwent brachiocephalic fistulograms for CAS but only received percutaneous transluminal angioplasty (PTA) was the control group. Patient demographic characteristics, AVF anatomy, SG type, and clinical outcomes were reviewed. The duration of primary cephalic arch patency after SG placement was compared with that after previous PTA.ResultsThe median AVF age at the time of data retrieval was 345 days. The primary patency of CAS after SG placement at 6 months, 12 months, and 3 years was 64%, 49.9%, and 23.5%, respectively. Primary cephalic arch patency was significantly associated with the SG diameter (P = .007) but not with cephalic vein–axillary vein junction anatomy, size of feeding artery, or SG length (P > .05). The primary patency of CAS in patients treated with PTA only (n = 31) at 6 months, 12 months, and 3 years was 61%, 35%, and 0%, respectively, which was significantly lower than that in patients treated with SG placement (P = .01).ConclusionsThis study showed that the primary patency of CAS after SG placement was significantly higher than that of PTA-only treatment. Moreover, primary cephalic arch patency after SG placement was significantly associated with the SG diameter.     

Angioplasty and stent placement in chronic occlusion of the superficial femoral artery: technique and results

PURPOSE: To improve the patency rate for angioplasty in chronic occlusion of the superficial femoral artery by deploying stents after angioplasty. MATERIALS AND METHODS: Angioplasty and stent placement were performed in 61 arteries in 48 male patients. The mean occlusion length was 13.5 cm and the mean stent length was 30 cm. Patency rates were analyzed at 6 months and at 1, 2, 3, and 4 years. The predictors of restenosis were analyzed by univariate and multiple logistic regression. RESULTS: Patency rates were 87% at 6 months, consisting of 74% primary, 6% primary assisted, and 7% secondary; 79% at 1 year, consisting of 47% primary, 19% primary assisted, and 13% secondary; 72% at 2 years, consisting of 36% primary, 26% primary assisted, and 10% secondary; 70% at 3 years, consisting of 26% primary, 22% primary assisted, and 22% secondary; and 63% at 4 years, consisting of 25% primary, 0% primary assisted, and 38% secondary. There was a 15% morbidity rate and one mortality as a result of retroperitoneal bleeding. Better patency rates were noted at all time intervals in diabetic limbs, 7-mm-diameter versus 10-mm-diameter stents, shorter obstructions and shorter stents, nonsmokers, in limbs in which urokinase was not necessary after stent deployment, and in limbs with an International Society of Cardiovascular Surgery (ISCVS) classification under 3. Patency rates were not affected by age, race, number of trifurcation vessels patent, experience in performing the procedures, and procedures requiring less time. By multivariate logistic analysis, the independent predictors of patency at 6 months were postprocedure ankle/brachial index (ABI) and shorter stent length; at 1 year, preprocedure ABI, shorter stent length, and the presence of diabetes; at 2 years, preprocedure ABI and the presence of diabetes; and at 3 years, the preprocedure ABI. CONCLUSIONS: The techniques used to reestablish antegrade flow in these superficial femoral arteries yielded a high success rate. In addition, the use of angioplasty with stents may improve patency rates over angioplasty without stents.