nitinol and Peripheral-Vascular-Diseases

A significant subset of patients with peripheral artery disease (PAD) has iliac artery involvement that requires treatment. The development of bare metal stents has improved the short- and long-term outcomes of endovascular repair and has become first line therapy. Open surgical bypass has been reserved for extremely complex anatomic morphologies or endovascular failures. It is unclear whether primary stenting is superior to angioplasty with provisional stenting but if angioplasty is used alone, it is likely only appropriate for the most focal lesions. Self-expanding and balloon-expandable stents have unique characteristics that are suitable to different lesion morphologies. Both stent-types have demonstrated similar outcomes. Herein, we review the practice and results of bare metal stents in the iliac arteries.

Topics: Alloys; Angioplasty; Arterial Occlusive Diseases; Blood Vessel Prosthesis Implantation; Endovascular Procedures; Humans; Iliac Aneurysm; Metals; Peripheral Vascular Diseases; Stents

In the femoropopliteal segment, endovascular revascularization techniques have gained the role as a first line treatment strategy. Nitinol stent placement has improved the short- and mid-term primary patency rates in most lesion types and is therefore widely applied. Stenting has several shortcomings as in-stent restenosis, stent fractures and foreign material being left behind in the vessel. The concept of atherectomy is plaque debulking. This results in a potential reduction of inflation pressure requirements in angioplasty. Stent placement and consecutive in-stent restenosis may be avoided. In this non systematic literature review, the performance of different atherectomy techniques, such as direct atherectomy, orbital atherectomy, laser debulking and rotational atherectomy in the treatment of complex femoropopliteal lesions, including long lesions, moderately to heavily calcified lesions as well as occlusions and in-stent restenosis, has been analyzed.

Topics: Alloys; Atherectomy; Constriction, Pathologic; Equipment Failure; Femoral Artery; Graft Occlusion, Vascular; Humans; Inguinal Canal; Lasers, Excimer; Peripheral Vascular Diseases; Popliteal Artery; Severity of Illness Index; Stents; Treatment Outcome; Vascular Calcification; Vascular Patency

The objective of this study was to assess the safety and efficacy of a dedicated venous stent (the VICI VENOUS STENT; VENITI, Fremont, Calif) for treatment of symptomatic iliofemoral venous outflow obstruction.. Thirty patients (24 female; median age, 43 years) were enrolled in the feasibility phase of an international, multicenter investigational device exemption trial from June 2014 to February 2015. All patients exhibited unilateral venous disease with ≥50% stenosis in the iliofemoral veins. Patients within 3 months of acute deep venous thrombosis or with prior surgical or endovascular intervention of the target vessel were excluded. Lesions were primarily of post-thrombotic causes (63%), with a left limb-right limb ratio of 5:1. Nine patients (30%) had lesions extending beneath the inguinal ligament. Median baseline stenosis was 91%; 11 patients (37%) had occlusions.. Fifty-one stents were implanted successfully in 30 patients. Median residual stenosis was 0%, as estimated by venography and intravascular ultrasound. Median follow-up was 701 days. At 12 months, primary, assisted-primary, and secondary patency was 93%, 96%, and 100%, respectively. The stent occluded in two patients through the 12-month window (occurring at 19 and 385 days). Both occlusions occurred in patients presenting with post-thrombotic obstruction. No patients in this cohort exhibited stent fracture at 12 months. Symptomatic improvement of ≥2 points on the Venous Clinical Severity Score was observed in 23 patients (85%) at 12 months (median score improvement, 5 points). There was a median 12-month pain reduction of 20 mm on the visual analog scale score and 15-point improvement on the Chronic Venous Insufficiency Questionnaire score. Scores improved significantly on all three clinical and quality of life scales at 6 and 12 months.. The VICI VENOUS STENT is safe and feasible for treatment of symptomatic iliofemoral venous obstruction, with excellent 12-month patency rates and significant improvement seen in clinical symptoms and quality of life indices. The pivotal phase (170 patients, 22 centers) of this investigational device exemption trial is currently ongoing.

Topics: Adult; Aged; Alloys; Constriction, Pathologic; Endovascular Procedures; Europe; Feasibility Studies; Female; Femoral Vein; Humans; Iliac Vein; Male; Middle Aged; Pain Measurement; Peripheral Vascular Diseases; Phlebography; Prospective Studies; Prosthesis Design; Quality of Life; Self Expandable Metallic Stents; Severity of Illness Index; Surveys and Questionnaires; Time Factors; Treatment Outcome; Ultrasonography, Interventional; United States; Vascular Patency; Young Adult

To evaluate the long-term efficacy and integrity of the PROTEGE EverFlex stent in superficial femoral artery (SFA) lesions in symptomatic patients with peripheral artery disease (PAD).. A prospective, multicenter, nonrandomized study enrolled 151 subjects (111 men; mean age 67.8 years, range 42-93) undergoing percutaneous treatment of de novo, restenotic, or reoccluded SFA lesions between August 11, 2006, and June 26, 2007. Subjects were scheduled to receive a single stent and be evaluated through 12 months following the implant procedure. Occlusions were present in 40% of the patients. Mean lesion length was 96.4 mm (range 10-150).. A total of 161 stents (158 EverFlex) were implanted in the 151 patients: single stents in 93.4% (141/151) and a second stent in 6.6% (10/151). One-year follow-up information was available for 88.7% (134/151) of the study participants; of the remaining 17 subjects, 6 subjects withdrew from the study, 2 were lost to follow-up, and 9 died. Freedom from restenosis data were available for 99.3% (133/134) of the subjects who completed a 12-month follow-up visit. The mean Rutherford classification fell from 2.8+/-0.8 (range 1-5) at baseline to 0.6+/-1.1 (range 0-5) at 12 months. The mean ankle-brachial index rose from 0.6+/-0.2 (range 0-1.4) at baseline to 0.9+/-0.2 (range 0-1.2) at 12 months. The rates for freedom from >50% restenosis at 6 and 12 months were 91.3% (95% CI 84.9% to 95.2%) and 72.2% (95% CI 63.8% to 79.6%), respectively. The freedom from target lesion revascularization rate at 12 months was 79.1% (95% CI 71.2% to 85.6%). The 1-year stent fracture rate was 8.1% (95% CI 4.0% to 14.4%).. The high freedom from >50% restenosis and low fracture rate at 12 months suggests that the PROTEGE EverFlex stent offers a safe and acceptably efficacious means of treating SFA lesions in symptomatic subjects with PAD.

Topics: Adult; Aged; Aged, 80 and over; Alloys; Angioplasty, Balloon; Atherosclerosis; Equipment Design; Female; Femoral Artery; Follow-Up Studies; Graft Occlusion, Vascular; Humans; Male; Middle Aged; Peripheral Vascular Diseases; Stents; Time Factors; Treatment Outcome

Primary stenting with self-expanding nitinol stents of the superficial femoral artery yielded improved morphological and clinical results compared with balloon angioplasty with optional stenting until 12 months in a randomized controlled trial. We now report 2-year data on restenosis and clinical outcomes of these patients.. Of 104 patients with chronic limb ischemia and superficial femoral artery obstructions, 98 (94%) could be followed up until 2 years after intervention for occurrence of restenosis (>50%) by duplex ultrasound and for clinical and hemodynamic outcome by treadmill walking distance and ankle brachial index. Restenosis rates at 2 years were 45.7% (21 of 46) versus 69.2% (36 of 52) in favor of primary stenting compared with balloon angioplasty with optional secondary stenting by an intention-to-treat analysis (P=0.031). Consistently, stenting (whether primary or secondary; n=63) was superior to plain balloon angioplasty (n=35) with respect to the occurrence of restenosis (49.2% versus 74.3%; P=0.028) by a treatment-received analysis. Clinically, patients in the primary stent group showed a trend toward better treadmill walking capacity (average, 302 versus 196 m; P=0.12) and better ankle brachial index values (average, 0.88 versus 0.78; P=0.09) at 2 years, respectively. Reintervention rates tended to be lower after primary stenting (17 of 46 [37.0%] versus 28 of 52 [53.8%]; P=0.14).. At 2 years, primary stenting with self-expanding nitinol stents for the treatment of superficial femoral artery obstructions yields a sustained morphological benefit and a trend toward clinical benefit compared with balloon angioplasty with optional stenting.

Topics: Aged; Alloys; Angioplasty, Balloon; Arterial Occlusive Diseases; Exercise Test; Female; Femoral Artery; Follow-Up Studies; Graft Occlusion, Vascular; Humans; Male; Middle Aged; Peripheral Vascular Diseases; Popliteal Artery; Stents; Treatment Outcome; Ultrasonography

To evaluate the AngioSculpt (ASC), a novel scoring balloon catheter designed to treat complex diffuse fibro-calcific atherosclerotic lesions and avoid device slippage during deployment, in patients with infra-popliteal disease.. The ASC incorporates a flexible nitinol scoring element containing three or more spiral struts which encircle a minimally compliant balloon to create focal concentration of the dilating force. Patients scheduled for percutaneous intervention of infra-popliteal arteries or planned amputation and with a reference vessel diameter of 1.5-3.5 mm were included in the study.. A total of 42 patients and 56 lesions were treated at five sites. Of these, 38 patients (90.5%) presented with critical limb ischemia (Rutherford Class > or = 4). The ASC was successfully deployed in 98.2% (55/56) of lesions attempted and was used as primary therapy without stenting in 89.3% (50/56). Lesion morphology was complex, including moderate/severe calcification in 73%, lesion length 33.9 +/- 42.2 mm, bifurcation in 26.8%, and ostial in 12.5%. There was no significant device slippage and no perforations. Post-ASC dissections occurred in only six (10.7%) lesions and were minor or resolved with stenting. In 13 patients initially referred for amputation, ASC treatment resulted in limb salvage.. The ASC is highly effective in a broad range of complex lesion morphologies, in most cases as stand-alone therapy, is associated with a very low complication rate and avoids device slippage during deployment. Additional studies are planned to assess the long term efficacy of this promising new technology.

Topics: Aged; Aged, 80 and over; Alloys; Angioplasty, Balloon; Critical Illness; Equipment Design; Europe; Female; Humans; Ischemia; Limb Salvage; Male; Peripheral Vascular Diseases; Popliteal Artery; Prospective Studies; Registries; Research Design; Severity of Illness Index; Treatment Outcome

To evaluate the effect of glycoprotein IIb/IIIa inhibition during nitinol stenting, of superficial femoral occlusive disease.. Stent implantation in the superficial femoral artery has been associated with suboptimal results while Glycoprotein IIb/IIIa inhibitors have shown improved procedural results during coronary intervention. We evaluated abciximab infusion during (Smart Stent) implantation in superficial femoral obstructions.. We conducted a randomized placebo controlled trial. The two primary end points include: (1) 9-month restenosis defined as a decrease in ankle brachial index and in-stent duplex ultrasound restenosis: (2) adverse events defined as death (30 days) or repeat revascularization within 9 months.. Twenty-seven patients were randomized to abciximab and 24 patients to control (placebo). The primary end point of cumulative restenosis occurred in 15.4% of patients administered abciximab and in 12% administered placebo (P = 0.873). The primary restenosis endpoint in diabetics and total occlusions were similar at 14.3% and 15.4% respectively. The composite end point of 30-day mortality and 9-month revascularization occurred in 5.8% abciximab and 0% (P = 0.274) placebo with no 30-day deaths. Graded treadmill time and Rutherford class were all significantly improved in both groups, but the abciximab group did not appear to demonstrate any identifiable effect.. (Smart Stent) nitinol stenting of the superficial femoral artery was associated with favorable functional outcomes at 9 months. Adjunctive abciximab did not appear to demonstrate any identifiable effect.

Topics: Abciximab; Aged; Aged, 80 and over; Alloys; Angiography; Angioplasty, Balloon; Antibodies, Monoclonal; Arterial Occlusive Diseases; Chi-Square Distribution; Female; Femoral Artery; Humans; Immunoglobulin Fab Fragments; Male; Middle Aged; Peripheral Vascular Diseases; Platelet Glycoprotein GPIIb-IIIa Complex; Stents; Treatment Outcome; Ultrasonography, Doppler, Duplex

Because stent implantation for disease of the superficial femoral artery has been associated with high rates of late clinical failure, percutaneous transluminal angioplasty is preferred for endovascular treatment, and stenting is recommended only in the event of suboptimal technical results. We evaluated whether primary implantation of a self-expanding nitinol (nickel-titanium) stent yielded anatomical and clinical benefits superior to those afforded by percutaneous transluminal angioplasty with optional secondary stenting.. We randomly assigned 104 patients who had severe claudication or chronic limb ischemia due to stenosis or occlusion of the superficial femoral artery to undergo primary stent implantation (51 patients) or angioplasty (53 patients). Restenosis and clinical outcomes were assessed at 6 and 12 months.. The mean (+/-SD) length of the treated segment was 132+/-71 mm in the stent group and 127+/-55 mm in the angioplasty group. Secondary stenting was performed in 17 of 53 patients (32 percent) in the angioplasty group, in most cases because of a suboptimal result after angioplasty. At 6 months, the rate of restenosis on angiography was 24 percent in the stent group and 43 percent in the angioplasty group (P=0.05); at 12 months the rates on duplex ultrasonography were 37 percent and 63 percent, respectively (P=0.01). Patients in the stent group were able to walk significantly farther on a treadmill at 6 and 12 months than those in the angioplasty group.. In the intermediate term, treatment of superficial-femoral-artery disease by primary implantation of a self-expanding nitinol stent yielded results that were superior to those with the currently recommended approach of balloon angioplasty with optional secondary stenting. (ClinicalTrials.gov number, NCT00281060.).

Topics: Aged; Alloys; Angioplasty, Balloon; Female; Femoral Artery; Follow-Up Studies; Humans; Intermittent Claudication; Ischemia; Leg; Logistic Models; Male; Middle Aged; Peripheral Vascular Diseases; Recurrence; Statistics, Nonparametric; Stents; Ultrasonography

To evaluate the safety and efficacy of an endoluminal prosthesis for treatment of peripheral arterial occlusive disease (PAOD).. A self-expanding endoprosthesis with an expanded polytetrafluoroethylene tube inside a nitinol support structure was implanted in 127 patients with symptomatic PAOD in the iliac (61 limbs) and femoral arteries (80 limbs). Clinical category status, ankle-brachial index, and color duplex flow imaging results were recorded before treatment, at discharge, and at 1, 3, 6, and 12 months after treatment. Aspirin was administered throughout the study, and heparin was administered during and for 2 days after the procedure.. Endoprosthesis deployment was technically successful in all patients. Complications occurred in 24 of 141 procedures and included three major complications. Early thrombosis (within 30 days) occurred in one iliac and three femoral arteries. Late restenosis or reocclusion was observed in five iliac and 14 femoral arteries within the 1st year. Primary patency rates in iliac arteries were 98% +/- 3% (standard error) and 91% +/- 4%, respectively, at 6 and 12 months after treatment. Primary patency rates in femoral arteries were 90% +/- 3% and 79% +/- 5%, respectively, at 6 and 12 months. Secondary patency rates were 95% and 93% for iliac and femoral arteries, respectively, at 12 months after treatment.. The device used in this study can be implanted without additional risks to the patient and provided encouraging patency rates up to 1 year.

Topics: Adult; Aged; Aged, 80 and over; Alloys; Angiography, Digital Subtraction; Arterial Occlusive Diseases; Equipment Design; Evaluation Studies as Topic; Female; Femoral Artery; Humans; Iliac Artery; Life Tables; Male; Middle Aged; Peripheral Vascular Diseases; Polytetrafluoroethylene; Prospective Studies; Risk Factors; Stents; Treatment Outcome; Vascular Patency

With 70 cm "cutter" valvulotomes for valvulotomy and an electronically steerable nitinol catheter to occlude venous tributaries with platinum coils, endovascular in situ saphenous vein (EISV) bypass can be safely performed from within the saphenous vein. To determine whether EISV bypass could reduce hospital length of stay (LOS) and perioperative morbidity without compromising patency, another 53 EISV bypasses for limb salvage were performed.. Tributary occlusion was accomplished with only fluoroscopic surveillance with a new, smaller, and more steerable silicone-tipped nitinol catheter.. Two (3.7%) wound complications occurred. The mean hospital LOS after operation was 4.2 days (range 2 to 29 days). All tributaries initially embolized remained occluded, and three "missed" arteriovenous fistulas were identified during follow-up extending to 15 month (mean 8.4 months). Eighty-eight percent (49 of 54) of phase II bypasses remained patent, whereas life-table analysis of all bypasses (phase I and II) was 77% (69/99) at 24 months follow-up (mean 13.6 months). By comparison, 41 infrainguinal saphenous vein in situ bypasses with "classic" open techniques were performed concurrently. The mean postoperative LOS was 11.6 days (range 4 to 42 days), wound complications occurred in 24% (10) of patients, and two "missed" arteriovenous fistulas were identified during follow-up. Eighty-three percent (34 of 41) of bypasses remain patent at 24 months follow-up (mean 16.2 months).. If EISV bypass long-term patency rates remain similar to classic in situ bypass patency results, the additional benefits of decreased hospital LOS, reduced wound-related complications, shortened recuperation, and therefore increased health care savings gives this endovascular technique strong consideration as the possible future operation for infrainguinal saphenous veins in situ bypass.

Topics: Aged; Aged, 80 and over; Alloys; Catheterization; Catheterization, Peripheral; Combined Modality Therapy; Female; Femoral Vein; Follow-Up Studies; Graft Occlusion, Vascular; Groin; Humans; Leg; Length of Stay; Life Tables; Male; Middle Aged; Peripheral Vascular Diseases; Popliteal Vein; Postoperative Complications; Saphenous Vein; Silicones; Stents; Ultrasonography; Vascular Patency

The ideal operative approach for infrainguinal in situ bypass grafting would render the saphenous vein (SV) valves incompetent while occluding venous tributaries from within the SV: an endovascular in situ SV bypass. Forty-six femoropopliteal-tibial in situ bypasses were performed in part by the endovascular occlusion technique. Valvulotomy was accomplished with a retrograde "cutter" valvulotome, and endoluminal cannulation of 84 SV tributaries was performed with a shape memory metal alloy (nickle-titanium), electronically steerable catheter under angioscopic surveillance. Sixty-nine SV tributaries (82%) were totally occluded and 15 (18%) were partially occluded with platinum occlusion coils. Twelve coils that "recoiled" into the SV lumen were retrieved uneventfully. The valvulotomes caused six SV perforations that were repaired without consequence. Intraoperative fluoroscopy confirmed coil placement and verified venous tributary occlusion, as well as SV graft patency. During short-term follow-up (mean 9.2 months; range 1 to 15 months), all patients have undergone ultrasonography of the in situ bypasses. All 69 of the SV tributaries that occluded initially have remained occluded and 84% (39/46) of the in situ bypasses have remained patent. This study demonstrates that an electronically steerable nitinol catheter can be used safely to occlude venous tributaries from within the SV. Endovascular occlusion of SV tributaries may ultimately obviate the need for long incisions the length of the leg, thus reducing wound-related problems and shortening recuperation.

Topics: Aged; Alloys; Arteriovenous Shunt, Surgical; Catheterization; Catheterization, Peripheral; Embolization, Therapeutic; Female; Femoral Vein; Humans; Male; Peripheral Vascular Diseases; Popliteal Vein; Saphenous Vein; Vascular Patency

Topics: Aged, 80 and over; Alloys; Angiography; Femoral Artery; Humans; Male; Peripheral Vascular Diseases; Popliteal Artery; Prosthesis Design; Stents; Treatment Outcome; Vascular Calcification; Vascular Patency; Vascular Surgical Procedures

Topics: Alloys; Aorta, Abdominal; Arterial Occlusive Diseases; Blood Vessel Prosthesis Implantation; Endovascular Procedures; Humans; Iliac Artery; Metals; Peripheral Vascular Diseases; Stents

This study evaluated the durability of nitinol stent placement in high-risk patients with chronic critical limb ischemia (CLI) and infrapopliteal lesions after suboptimal balloon angioplasty.. Between January 2006 and January 2009, 53 high-risk patients (24 women; mean age, 71.8 +/- 5.1 years) with CLI underwent infragenicular stent placement with a 4F sheath-compatible self-expanding nitinol stent. Patients had three or more serious cardiopulmonary comorbidities, including chronic obstructive pulmonary disease, congestive heart failure, coronary artery occlusive disease, American Society of Anesthesiologists score >/=3, previous myocardial infarction, coronary stent or bypass, or infection after peripheral revascularization. Endovascular therapy was performed in 30 stenoses and 23 occlusions in 53 patients. The mean stenosis length was 5.5 +/- 1.9 cm. The mean occlusion length was 6.5 +/- 2.9 cm. The mean follow-up was 24.1 +/- 7.3 months and consisted of clinical examination, ankle-brachial index (ABI) measurements, and duplex ultrasound imaging. Digital subtraction angiography was performed if restenosis or reocclusion was suspected.. The technical success rate was 98.1%. The 24-month cumulative primary patency rate was 75.5%. During the follow-up, two patients underwent successful repeat angioplasty, and four patients required crural bypass. The 24-month secondary patency and freedom from amputation rates were 88.7% and 88.7%, respectively. The mean ABI increased significantly at 12 and 24 months (P < .001). Risk stratification to detect predictors that influenced the patency rate showed that proximal lesions had significant better patency than distal crural lesions (83.3% vs 65.2%, P = .04). The morphology of the lesions (stenoses vs occlusions, P = .88) did not seem to influence primary patency. Four patients died from nonprocedure-related causes during the follow-up, including lung cancer, myocardial infarction, and glioblastoma multiforme. No procedure-related deaths were recorded.. The 2-year outcome of our series underscores the value of infrapopliteal nitinol stent placement as a durable bailout treatment option in high-risk CLI patients with suboptimal angioplasty.

Topics: Aged; Alloys; Amputation, Surgical; Angiography, Digital Subtraction; Angioplasty, Balloon; Ankle Brachial Index; Constriction, Pathologic; Critical Illness; Female; Humans; Ischemia; Kaplan-Meier Estimate; Limb Salvage; Lower Extremity; Male; Peripheral Vascular Diseases; Prosthesis Design; Recurrence; Retrospective Studies; Risk Assessment; Risk Factors; Stents; Time Factors; Treatment Outcome; Ultrasonography, Doppler, Duplex; Vascular Patency; Vascular Surgical Procedures

The purpose of this study was to evaluate the safety and efficacy of debris-capture for distal protection using the FilterWire EZ Embolic Protection System (Boston Scientific, Mountain View, CA) with the additional aim to further define the incidence of distal embolization during superficial femoral artery (SFA) interventions. A prospective, single-centre registry was designed to evaluate the performance of the FilterWire EZ in capturing debris during standard SFA percutaneous intervention. The PRO-RATA study included 30 patients suitable for PTA (Fontaine IIb to III or Rutherford I to II classification). The primary end points were occurrence of distal embolization or decreased runoff, improvement in ankle-brachial index ankle-brachial index (ABI) after the procedure, and number of filters containing emboli. Secondary end points included major adverse events (i.e., procedure- or device-related death and/or clinical target lesion revascularisation), device delivery, deployment success, and incidence of embolic recovery (patients with device success exhibiting embolic protection in the filter). Procedural success was determined as ≤30% residual stenosis with no worsening of distal runoff as determined on angiography. A total of 29 patients (age 66.2 ± 12 years; total no. of limbs = 30; total no. of lesions = 30) suitable for PTA were enrolled in the study between February 2007 and March 2008. There were 26 patients with claudication (Fontaine IIB) and 3 patients with stage IV peripheral vascular disease. In one patient, lesions in both legs were treated. No procedural or device-related complications occurred. The average degree of stenosis was 86 ± 7%. Stenosis length ranged from 8 to 88 mm. The average degree of residual stenosis was 10 ± 10%. ABI improved from 0.56 ± 0.16 to 0.92 ± 0.19 (P < 0.05). No restenosis or dissection was seen at 1-month ultrasound follow-up. Macroscopic debris was found in 27 of 30 filters of all distal protection devices used in all 29 patients. Debris particle size ranged from 90 to 2000 μm (1200 ± 640). Histological debris analysis showed platelets, erythrocytes, inflammatory cells, extracellular matrix, and cholesterol as being the major components of emboli. Additional immunochemistry showed no correlation between lesion morphology and debris components. The FilterWire EZ is easy and safe to handle. The system caused no complications. In all cases, macroscopic debris was captured. Using a distal protection device during fem

Topics: Aged; Alloys; Angiography; Angioplasty; Embolism; Female; Femoral Artery; Filtration; Humans; Immunohistochemistry; Leg; Male; Peripheral Vascular Diseases; Prospective Studies; Registries; Stents; Treatment Outcome

Different stents in infrainguinal arteries have recently been associated with stent fractures and unfavorable clinical outcome, although data is limited regarding fractures of the Xpert selfexpanding nitinol stent. Thus, purpose of the present investigation was to evaluate its incidence and clinical implications in lower limb arteries.. Fifty-three consecutive patients (53 limbs) with peripheral arterial disease underwent secondary Xpert stent implantation due to suboptimal primary balloon angioplasty (PTA). Median age was 76 years. Stent fractures were evaluated by plain X-ray at median follow-up of 16 months. Stent patency was assessed by duplex ultrasound and sustained clinical improvement was defined as improvement of the ABI of > or = 0.10 together with improvement of at least one Rutherford class above the baseline finding throughout follow-up.. Median length of femoropopliteal and infrapopliteal lesion was 3.0 and 2.3 cm, respectively. Sixtyfive stents were implanted in 43 limbs with femoropopliteal and 10 stents in 10 limbs with infrapopliteal lesion, respectively. Stent fractures occurred in 3 of 43 limbs (7.0%) of patients with femoropopliteal lesion with stent-based fracture rate of 4.6%. All fractured stents showed multiple struts fractures and occurred in the distal and middle superficial femoral artery. No stent fracture was observed in infrapopliteal lesions. The fractured stents were not associated with any clinical deterioration. Sustained clinical improvement was 71.0% and 54.6% for femoropopliteal and infrapopliteal lesions, respectively. Stent patency assessed by duplex was 65.2 and 63.9% for femoropopliteal and infrapopliteal lesions, respectively.. Fractures of the Xpert stent were seldom and not associated with unfavorable clinical outcome at midterm follow-up.

Topics: Aged; Aged, 80 and over; Alloys; Angioplasty, Balloon; Equipment Failure Analysis; Female; Femoral Artery; Humans; Lower Extremity; Male; Middle Aged; Peripheral Vascular Diseases; Popliteal Artery; Prosthesis Design; Prosthesis Failure; Radiography; Retrospective Studies; Stents; Time Factors; Treatment Outcome; Ultrasonography, Doppler, Duplex; Vascular Patency

For peripheral endovascular intervention, self-expanding (SE) stents are commonly oversized in relation to target arteries to assure optimal wall apposition and prevent migration. However, the consequences of oversizing have not been well studied. The purpose of this study was to examine the effects of SE stent oversizing (OS) with respect to the kinetics of late stent expansion and the long-term histological effects of OS. Pairs of overlapped 8 x 28-mm Nitinol SE stents were implanted into the iliofemoral arteries of 14 Yucatan swine. Due to variations in target artery size, the stent-to-artery ratio ranged from 1.2:1 to 1.9:1. Lumen and stent diameters were assessed by quantitative angiography at the time of implantation. Following angiographic assessment at 6 months, stented arteries were perfusion-fixed, sectioned, and stained for histological analysis. Immediately following implantation, the stents were found to be expanded to a range of 4.7-7.1 mm, largely conforming to the diameter of the recipient target artery. The stents continued to expand over time, however, and all stents had enlarged to nearly their 8-mm nominal diameter by 6 months. The histological effects of OS were profound, with marked increases in injury and luminal area stenosis, including a statistically significant linear correlation between stent-to-artery ratio and area stenosis. In this experimental model of peripheral endovascular intervention, oversized Nitinol SE stents are constrained by their target artery diameter upon implantation but expand to their nominal diameter within 6 months. Severe OS (stent-to-artery ratio >1.4:1) results in a profound long-term histological response including exuberant neointimal proliferation and luminal stenosis.

Topics: Alloys; Animals; Fluoroscopy; Linear Models; Peripheral Vascular Diseases; Prosthesis Design; Prosthesis Fitting; Stents; Swine; Tunica Intima; Vascular Patency

Topics: Aged; Alloys; Blood Vessel Prosthesis; Device Removal; Elasticity; Exercise; Female; Humans; Knee Joint; Peripheral Vascular Diseases; Prosthesis Failure; Stents

To investigate the impact of nitinol stenting of superficial femoral artery (SFA) lesions with a maximum length of 10 cm (TASC-II A or B) on 1-year outcomes compared to a historical study cohort from the Femoral Artery Stent Trial (FAST).. Between January 2004 and August 2005, 6 study sites enrolled 110 symptomatic patients (75 men; mean age 68+/-9 years) with a single de novo >70% SFA lesion <10 cm long treated with the self-expanding nitinol Conformexx stent. The primary study endpoint was binary restenosis determined by duplex ultrasound at 12 months. Secondary 12-month endpoints were target lesion revascularization (TLR), ankle-brachial index (ABI), mean Rutherford category, >1-class change in Rutherford category, and major adverse events. Data were analyzed according to the intention-to-treat principle and according to the actual treatment received ("on treatment" analysis). Outcomes were compared to the historical balloon angioplasty (BA) arm and the Luminexx 3 stent arm of the randomized FAST study.. Technical success was achieved in 106 (96%) patients; at 1 year, the primary endpoint of ultrasound-assessed binary restenosis was reached in 14 (23.3%) of 60 patients (95% CI 13.4% to 36%). This restenosis rate was lower versus the historical BA (38.6%, p=0.057) or Luminexx 3 stent controls (31.7%, p=0.284) from FAST. The clinically driven TLR was 7.4% (7 of 94 clinically controlled patients), which was also lower compared to 18.3% (p=0.098) and 14.9% (p=0.267) for the historical BA and Luminexx 3 stent groups, respectively. The mean Rutherford category was reduced from 2.75+/-0.79 to 0.94+/-1.38 (p<0.0001); 85.1% were improved by at least 1 Rutherford category. The ABI increased from 0.62+/-0.15 to 0.85+/-0.20 (p<0.0001).. This study of patients with SFA lesions documented favorable outcomes using nitinol stents in TASC-II A or B lesions after 1 year. The study was underpowered to prove superiority of the Conformexx nitinol stent design compared to historical balloon only or Luminexx 3 stent groups.

Topics: Aged; Alloys; Blood Vessel Prosthesis Implantation; Female; Femoral Artery; Humans; Male; Peripheral Vascular Diseases; Stents; Treatment Outcome; Ultrasonography; Vascular Patency

The feasibility of self-expanding nitinol stents for treatment of infragenicular arteries following unsuccessful balloon angioplasty was assessed. Options for lower limb percutaneous revascularization are limited, especially for complex vessel obstruction. Depending on the lesion and the experience of the interventionalist, the failure rate of balloon angioplasty (PTA) ranges between 10 and 40%. Until recently, no self-expanding stent for the use in the infragenicular arteries was available. This is the first report of the results for 18 consecutive patients who received 4F sheath compatible self-expanding nitinol stents following unsuccessful PTA or early restenosis. Twenty-four stents were implanted in 21 lesions for various indications residual stenosis >50% due to heavy calcification, flow-limiting dissection, occluding thrombus resistant to thrombolyis, thrombaspiration, and PTA, and early restenosis after previous PTA. Stent implantation was feasible in all cases. No complications occurred. After the stent implantation, all primarily unsuccessful interventions could be transformed into successful procedures with no residual stenosis >30% in any case. After 6 +/- 2 months, two of the 18 patients died, and 14 of the 16 remaining patients improved clinically. At follow-up, the patency could be assessed in 14 stented arteries. Three stents were occluded, one stent showed some neointimal hyperplasia (50-70% restenosis), the remaining ten stents showed no restenosis (0-30%). The use of self-expanding nitinol stents in tibioperoneal and popliteal arteries is a safe and feasible option for the treatment of unsuccessful PTA. The 6-months patency is high.

Topics: Aged; Aged, 80 and over; Alloys; Angioplasty, Balloon; Arterial Occlusive Diseases; Feasibility Studies; Female; Humans; Leg; Male; Middle Aged; Peripheral Vascular Diseases; Prospective Studies; Radiography, Interventional; Stents; Treatment Outcome; Ultrasonography, Interventional; Vascular Patency

This analysis proposes safety and performance goals for prospective single-arm trials of bare nitinol stents to treat patients with debilitating claudication associated with femoropopliteal (FP) atherosclerotic lesions.. To date there have been no analyses of clinical trials data to set efficacy and safety benchmarks for new bare nitinol stents in the treatment of claudication from FP disease. Industry has been reluctant to sponsor studies of nitinol stents due to logistical barriers.. VIVA Physician's, Inc. (VPI) analyzed subject-level data from the PTA control arm of three randomized FDA device trials conducted by industry. Subjects with Rutherford category 2-4 claudication and FP lesion lengths 4-15 cm with 12 month duplex ultrasound (DUS) assessment were identified. These data were combined with the results of a survey of the medical literature (1990-2006) for similar subjects.. Analysis of the industry derived control arm PTA data identified 116 patients (mean lesion length 8.7 cm) with a 12 month DUS defined FP patency of 28%. A similar cohort of 191 patients was identified from the medical literature in which the 12-month vessel patency equaled 37%; from these combined patient cohorts, expected vessel patency for PTA was estimated to equal 33%.. Based on the PTA performance efficacy rate of 33% derived from industry clinical trial data and the medical literature, and the requirement that the bare nitinol stent 12-month efficacy performance goal be set to equal twice this rate, the patency efficacy goal equals 66%. Additional information is provided on safety and other reporting standards and stent integrity evaluation for bare metal stents.

Topics: Alloys; Angioplasty, Balloon; Atherosclerosis; Clinical Trials as Topic; Endpoint Determination; Femoral Artery; Guidelines as Topic; Humans; Intermittent Claudication; Peripheral Vascular Diseases; Popliteal Artery; Prospective Studies; Randomized Controlled Trials as Topic; Registries; Research Design; Sample Size; Severity of Illness Index; Stents; Treatment Outcome; Vascular Patency; Vascular Surgical Procedures

To evaluate the primary success and short-term patency associated with a new 4-F sheath-compatible self-expanding nitinol stent after failed conventional angioplasty of distal popliteal and infrapopliteal lesions in severe lifestyle-limiting claudication (LLC) and chronic critical limb ischemia (CLI).. Between May 2003 and July 2005, 35 patients with Rutherford category 3-5 disease (16 patients with CLI, 19 patients with LLC) underwent percutaneous transluminal angioplasty (PTA) and stent implantation. Indications for stent placement were residual stenosis, flow-limiting dissections, or elastic recoil after PTA. Before and after the intervention and during the 6-month follow-up, clinical investigation, color-flow and duplex Doppler ultrasonography, and digital subtraction angiography were performed. Technical success, primary patency at 6 months, clinical improvement as defined by Rutherford with clinical and hemodynamic measures, and complications were evaluated.. A total of 22 patients underwent distal popliteal artery stent placement and 13 underwent tibioperoneal artery stent placement. Stent implantation was successfully performed in all patients. After stent placement, the primary cumulative patency rate for the study group at 6 months was 82%. The mean resting ankle-brachial index at baseline was 0.50 +/- 0.16 and significantly increased to 0.90 +/- 0.17 at 12-24 hours after intervention and 0.82 +/- 0.24 at latest follow-up (P < .001 for both). The sustained clinical improvement rate was 80% at the 6-month follow-up. The 6-month limb salvage rate regarding major amputation was 100%. The rate of major complications was 17%.. Infrapopliteal application of the new nitinol stent is a safe, feasible, and effective method with good short-term patency rate in the treatment of severe LLC and chronic CLI.

Topics: Aged; Aged, 80 and over; Alloys; Angiography, Digital Subtraction; Angioplasty; Angioplasty, Balloon; Critical Illness; Feasibility Studies; Female; Follow-Up Studies; Humans; Intermittent Claudication; Ischemia; Kaplan-Meier Estimate; Laser-Doppler Flowmetry; Limb Salvage; Lower Extremity; Male; Middle Aged; Peripheral Vascular Diseases; Popliteal Artery; Prosthesis Design; Retrospective Studies; Severity of Illness Index; Stents; Tibial Arteries; Time Factors; Treatment Failure; Treatment Outcome; Ultrasonography, Doppler, Color; Vascular Patency

The present report describes three young adults with nutcracker syndrome caused by left renal vein stenosis managed with nitinol stent implantation. The patients treated included a 20-year-old woman with persistent microhematuria and dyspareunia and two 18-year-old men with proteinuria, hematuria, and flank pain. All three patients were asymptomatic after a follow-up of 14-18 months.

Topics: Adolescent; Adult; Alloys; Aorta, Abdominal; Constriction, Pathologic; Drug-Eluting Stents; Dyspareunia; Female; Hematuria; Humans; Male; Mesenteric Artery, Superior; Peripheral Vascular Diseases; Proteinuria; Renal Veins

Topics: Alloys; Catheterization, Peripheral; Equipment Design; Femoral Artery; Foreign Bodies; Hemostasis, Surgical; Humans; Peripheral Vascular Diseases; Surgical Staplers; Surgical Stapling; Titanium

Topics: Alloys; Angioplasty, Balloon; Confounding Factors, Epidemiologic; Femoral Artery; Humans; Intermittent Claudication; Ischemia; Leg; Peripheral Vascular Diseases; Research Design; Stents

Topics: Alloys; Angioplasty, Balloon; Humans; Peripheral Vascular Diseases; Recurrence; Stents; Vascular Patency

Topics: Alloys; Angioplasty, Balloon; Angiotensin-Converting Enzyme Inhibitors; Humans; Peripheral Vascular Diseases; Stents

To determine and compare the rates of in-stent restenosis, late clinical deterioration, and stent fractures in nitinol stents versus Wallstents implanted for suboptimal angioplasty in the superficial femoral artery (SFA).. Interrogation of an angioplasty database identified 286 consecutive patients (178 men; mean age 67+/-10 years, range 44-87) with severe claudication (n=254) or critical limb ischemia (n=32) who had stents implanted after suboptimal angioplasty over a 5-year period. Wallstents with a mean stented lesion length of 107+/-71 mm were implanted in 116 patients, while nitinol stents were used in 170 patients: 45 SMART stents (mean stented lesion length 139+/-88 mm) and 125 Dynalink/Absolute stents (mean stented lesion length 125+/-84 mm). Patients were followed for in-stent restenosis (>50%) by duplex ultrasound, clinical deterioration by at least 1 Fontaine stage compared to baseline, and stent fractures by biplanar radiography.. In-stent restenosis rates at 1, 2, and 3 years were 46%, 66%, and 72% for Wallstents compared to 20%, 36%, and 53% for nitinol stents (p<0.001), respectively, without significant difference between the 2 nitinol stent groups (p=0.59). Clinical deterioration at 1, 2, and 3 years was found in 10%, 15%, and 18% with Wallstents versus 4%, 5%, and 5% with nitinol stents (p=0.014), respectively, without difference between the 2 nitinol stent groups (p=0.47). Fracture rates were 19% for Wallstents after a mean 43+/-24 months, 28% for SMART stents after mean 32+/-16 months, and 2% for Dynalink/Absolute stents after a mean 15+/-9 months.. Intermediate-term in-stent restenosis remains a major problem even with current nitinol stent technology; however, clinical deterioration seems no matter of serious concern with SMART and Dynalink/Absolute stents. Stent fractures may be lower with Dynalink/Absolute stents, but randomized head-to-head comparisons are needed to validate these data.

Topics: Adult; Aged; Aged, 80 and over; Alloys; Angioplasty, Balloon; Arterial Occlusive Diseases; Blood Vessel Prosthesis Implantation; Female; Femoral Artery; Humans; Leg; Male; Middle Aged; Peripheral Vascular Diseases; Prosthesis Failure; Recurrence; Stents; Treatment Outcome; Ultrasonography, Doppler, Duplex; Vascular Patency

The purpose of this study was to evaluate the patentcy rates and physiological effectiveness of angioplasty and stenting as a primary therapy for superficial femoral (SFA), popliteal (POP), and tibial (TIB) arterial occlusive disease. Seventy-eight patients had stents placed in the infra-inguinal vessels between January 1, 2001, and July 31, 2004. We collected data on patient demographics, symptoms, as well as pre- and postprocedure ankle-brachial index (ABI) and angiographic findings. Patency rates at 6 months, 12 months, and 24 months were analyzed by life table methods. Thirty-one men and 47 women had a mean age of 68 years (range 36-94 years). Risk factors included diabetes in 50 per cent, hypertension in 79 per cent, smoking in 41 per cent, and end-stage renal disease in 10 per cent. The indications for intervention were claudication in 52 per cent and limb salvage in 48 per cent of patients. Stents were placed in the SFA in 54 patients (69%), in the POP in 15 patients (18%), and in the TIB artery in 6 patients (8%). Average follow-up was 11.2 months. The mean postprocedural increase in ABI was 0.29. The 6-month, 1-year, and 2-year primary patency rates were 83 per cent, 58 per cent, and 47 per cent, respectively. Limb salvage was achieved in 66 per cent of patients treated for limb-threatening ischemia. There was one major and three minor complications. Stenting of the infra-inguinal vessels has a low morbidity, high success rate, and acceptable patency and limb-salvage rates.

Topics: Adult; Aged; Aged, 80 and over; Alloys; Atherosclerosis; Female; Femoral Artery; Humans; Male; Middle Aged; Peripheral Vascular Diseases; Popliteal Artery; Prospective Studies; Stents; Tibial Arteries

To investigate a new method of stent deployment using commercially available self-expanding stents to treat bifurcation lesions, providing complete lesion coverage without obstructing branches.. After preliminary in vitro and clinical testing with biliary obstructions, 11 vascular obstructive lesions in 10 patients (7 men; mean age 63 years, range 32-81) were treated by percutaneous Y-shaped stenting. Five patients had iliac arterial stenoses involving the iliac bifurcation; the other 5 patients had 6 central venous obstructions involving branch points. Bifurcated stents were constructed in situ by deploying a nitinol stent extending into one branch and selective balloon fracturing of struts to create a fenestration. A second stent was deployed through the hole, followed by symmetrical fracturing of struts in the second stent to form a Y-shaped configuration.. All deployments were technically successful and resulted in complete coverage of the bifurcation lesions. Protrusion of fractured stent material into flow lumens was minor as determined by angiography, intravascular ultrasound, and passage of balloons, but it required the stents to be oversized. The lengths and luminal diameters were tailored for each arm of the Y-shaped stents.. In situ creation of a Y-shaped stent using 2 self-expanding nitinol stents is a feasible option with potential advantages in the treatment of obstructive lesions involving a bifurcation.

Topics: Adult; Aged; Aged, 80 and over; Alloys; Arterial Occlusive Diseases; Blood Vessel Prosthesis Implantation; Female; Humans; Male; Middle Aged; Peripheral Vascular Diseases; Prosthesis Design; Stents; Treatment Outcome

To retrospectively evaluate the performance of a new self-expanding nitinol stent in the treatment of lower limb arterial occlusive lesions.. The Sinus stent is a flexible, laser-cut device with good radiopacity and radial strength, allowing precise placement via a 7-F introducer, even in tortuous arteries. Over a 3.5-year period, 315 patients (254 men; mean age 64.9+/-10.8 years, range 39-93) had 403 lower limb lesions treated: 172 iliac (132 stenoses, 40 occlusions), 204 femoral (131 stenoses, 73 occlusions), and 27 popliteal (19 stenoses, 8 occlusions). The majority of patients (272, 86%) were in stage IIb of Fontaine's classification, 31 (10%) in stage III, and 12 (4%) in stage IV. Mean lesion lengths were iliac: 51.9+/-32.1 mm, femoral: 66.3+/-51.5 mm, and popliteal: 44.3+/-27.2 mm. Indications for stenting were 222 postdilation residual stenoses, 125 dissections, and 35 restenoses; 21 lesions were directly stented.. Immediate technical success was 100%. Clinical success was 98%. The ankle-brachial index increased from 0.62+/-0.12 to 0.91+/-0.14. In 64 lesions, there were 3 early thromboses. Mean follow-up was 16.1+/-9.7 months (range to 40). There were 79 restenotic episodes: 14 iliac, 56 femoral, and 9 popliteal. Primary and secondary patencies for all lesions at 3 years were 72.5%+/-6.6% and 81.8%+/-5.9%, respectively. Stenoses demonstrated better patency than occlusions (primary: 78.0%+/-7.3% versus 60.2%+/-7.1%, p<0.001; secondary: 86.8%+/-6.1% versus 71.3%+/-6.7%, p<0.001). Men had better secondary patency at 3 years (83.7% versus 73.4%, p<0.05). For femoral lesions >8 cm, the results were acceptable for stenoses (66.7% primary and secondary patency at 3 years), but for lengthy occlusions, the restenosis rate was high (50.0% for occlusions versus 25.0% for stenoses, p<0.05).. Angioplasty with the Sinus stent seems safe and effective in the treatment of peripheral arterial occlusive diseases, giving excellent results at the iliac and common femoral artery levels. Treatment results are better for stenoses than for occlusions. An occlusion length

Topics: Adult; Aged; Aged, 80 and over; Alloys; Angioplasty, Balloon; Arterial Occlusive Diseases; Female; Humans; Leg; Male; Middle Aged; Peripheral Vascular Diseases; Prosthesis Design; Retrospective Studies; Risk Factors; Statistics, Nonparametric; Stents; Survival Analysis; Treatment Outcome

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.. 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.. 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.. 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.

Topics: Adult; Aged; Aged, 80 and over; Alloys; Angioplasty, Balloon; Arterial Occlusive Diseases; Constriction, Pathologic; Female; Femoral Artery; Humans; Longitudinal Studies; Male; Middle Aged; Patient Selection; Peripheral Vascular Diseases; Popliteal Artery; Safety; Stents; Treatment Outcome

To compare the nitinol occlusion plug with standard stainless steel coils for the occlusion of moderate-size peripheral veins.. The nitinol plug is a braided multilayered vascular occlusion device filled with thrombogenic polyester fibers. It is self-expanding and can be recaptured into its 6-F introducing sheath for repositioning prior to detachment. Ten occlusion procedures were performed in five dogs from a retrograde transjugular venous approach. Five nitinol plugs (diameter: 7.4 mm +/- 0.5) were deployed in five femoropopliteal veins (diameter: 6.5 mm +/- 0.7; mean oversizing 14.6%). Two sequential Gianturco coils (diameter: 7.4 mm +/- 0.9) were deployed in the corresponding contralateral veins (diameter: 6.2 mm +/- 0.8; mean oversizing 19.6%). Follow-up venography was performed at 1 month, following which the animals were killed and the vessels were explanted.. Time-to-occlusion was significantly shorter with the nitinol plug as compared to two Gianturco coils (4.2 minutes +/- 3.4 vs 25.6 minutes +/- 14.1, respectively [P < .03]). At 1 month all but one coil-doublet (80%) had recanalized or migrated, compared to only one nitinol occluder (20%, P < .04). Histopathologic examination of plug-occluded veins showed a uniform organized matrix and underlying intimal proliferative response.. A single nitinol occluder resulted in significantly faster occlusion time and significantly lower recanalization or migration rate than two Gianturco coils, in moderate-size peripheral veins.

Topics: Alloys; Animals; Collateral Circulation; Dogs; Embolization, Therapeutic; Equipment Design; Femoral Vein; Fibrosis; Follow-Up Studies; Foreign-Body Migration; Peripheral Vascular Diseases; Phlebography; Polyesters; Popliteal Vein; Stainless Steel; Statistics as Topic; Time Factors; Tunica Intima

Our objective was to compare intravascular sonography with digital subtraction angiography (DSA) in the assessment of luminal dimension and morphologic features of endovascular stents and stent grafts.. Thirty-seven pelvic and 24 femoral stents (12 Wall-stents; 27 covered and 22 uncovered nitinol stents) in 50 patients were evaluated 15 +/- 10 months after implantation by DSA and intravascular sonography. The degree of maximum instent restenosis as revealed by DSA and intravascular sonography was compared for each location. Morphologic features of the stents and stenoses were also assessed.. Intravascular sonography and DSA correlated well (R2 = .96) in determining in-stent restenosis. In-stent restenosis was underestimated by 13% +/- 6% by DSA compared with intravascular sonography. Differences in determining in-stent restenosis with intravascular sonography and DSA were not associated with severity of stenosis or type of stent. Intravascular sonography revealed incomplete expansion of stents in 21 cases, whereas DSA revealed incomplete expansion of stents in seven cases. The intra- and interobserver variabilities in our study were 4% and 5%, respectively.. In-stent restenoses are underestimated with DSA. Intravascular sonography is superior to DSA for detection of incomplete stent expansion.

Topics: Alloys; Angiography, Digital Subtraction; Ankle; Arterial Occlusive Diseases; Arteriosclerosis; Blood Pressure; Blood Vessel Prosthesis; Blood Vessel Prosthesis Implantation; Brachial Artery; Evaluation Studies as Topic; Female; Femoral Artery; Graft Occlusion, Vascular; Humans; Intermittent Claudication; Male; Middle Aged; Observer Variation; Pelvis; Peripheral Vascular Diseases; Prosthesis Design; Recurrence; Regression Analysis; Sensitivity and Specificity; Stents; Surface Properties; Ultrasonography, Interventional

To evaluate a new self-expanding nitinol coil stent in stenotic or occluded peripheral arteries.. Seventy-three symptomatic patients (58 men; mean age 67 years) were treated with nitinol stents for lesions in the iliac artery (9 stenoses); superficial femoral artery (SFA) (39 stenoses, 6 occlusions); popliteal artery and tibioperoneal trunk (9 stenoses, 7 occlusions); and 3 bypass grafts. Mean diameter stenosis was 84.4% +/- 9.9% (range 75% to 100%), and mean lesion length was 45 +/- 23 mm (range 20 to 120 mm).. Eighty-eight 40-mm-long stents with diameters between 5 and 8 mm were implanted percutaneously for suboptimal dilation (n = 45); dissection (n = 21); and restenosis (n = 7). All stents but one were implanted successfully; the malpositioned stent was removed, and another stent was successfully deployed. There were 3 (4.1%) failures due to thrombosis at 24 hours. During the mean 16-month follow-up (range to 44 months), 4 restenoses (3 femoral, 1 popliteal) have occurred; 2 were treated with repeat dilation and 2 underwent bypass. Primary and secondary patency rates at 18 months were 87% and 90%, respectively, for all lesions (iliac: 100% for both; femoral: 85% and 88%; popliteal: 87% and 100%).. This new nitinol stent seems to be safe and effective with favorable long-term results, even in distal SFA lesions and popliteal arteries. Its flexibility and resistance to external compression allow its placement in tortuous arteries and near joints.

Topics: Aged; Alloys; Angioplasty, Balloon; Arterial Occlusive Diseases; Constriction, Pathologic; Equipment Design; Evaluation Studies as Topic; Female; Follow-Up Studies; Humans; Life Tables; Male; Peripheral Vascular Diseases; Stents; Time Factors; Treatment Outcome; Vascular Patency