Carotid artery stenting and patient outcomes: the CABANA surveillance study.

OBJECTIVES: The purpose of the prospective, multicenter, nonrandomized CABANA study was to evaluate periprocedural clinical outcomes in high surgical risk patients with carotid artery stenosis treated with the Carotid WALLSTENT plus FilterWire EZ Embolic Protection System by a diverse group of clinicians. BACKGROUND: There is a need for additional evidence evaluating carotid artery stenting (CAS) performed by operators with various experience and training levels. METHODS: The study enrolled symptomatic (≥50% carotid artery stenosis) and asymptomatic (≥80% carotid stenosis) patients at high risk for carotid endarterectomy. Study centers were grouped into three tiers based on previous CAS experience while individual operators were grouped by their CAS training. The primary endpoint was the 30-day composite of major adverse events [MAEs; including stroke, death, and myocardial infarction (MI)]. Individual event rates were evaluated across the overall study, and by center experience and physician training tier. RESULTS: Of 1,097 enrolled patients, 1,025 were evaluable for 30-day MAE rate. The stroke rate (3.3%) was a major contributing factor in the overall MAE rate (4.6%). Mortality was 1.3% and the MI rate was 0.5%. There was no statistically significant association between MAE rates among the center experience tiers (P = 0.61) nor among the operator training categories (P = 0.26). CONCLUSIONS: CAS with the Carotid WALLSTENT and FilterWire EZ yielded a low 30-day MAE rate that did not differ significantly across operator experience and training levels. Clinicaltrials.gov identifier: NCT00741091.

Influence of stent type on hemodynamic depression after carotid artery stent placement.

PURPOSE: To assess the effect of stent type on hypotension and bradycardia after carotid artery stent placement. MATERIALS AND METHODS: A retrospective analysis on a prospectively maintained database was conducted in 256 patients (126 men; mean age, 71.8 years +/- 8.6; 194 de novo lesions) undergoing carotid artery stent placement between January 1996 and January 2007 by using self-expanding stents. Braided Elgiloy stents (Wallstents) were used in 44 of the 256 patients (17.2%) and slotted-tube nitinol stents were deployed in 212 (82.8%). Bivariate and multivariable logistic regression models were used to determine the influence of stent design on procedural and 24-hour hypotension and bradycardia. RESULTS: Procedural hemodynamic depression (HD) was encountered in 73 of the 256 patients (28.5%) due to hypotension in 24 (9.4%), bradycardia in 12 (4.7%), or both in 37 (14.5%) patients. Rates of procedural hypotension were 11.3% with nitinol stents and 0% with braided Elgiloy stents (P = .0188). Persistent postprocedural HD occurred in 91 of the 256 patients (35.5%) due to hypotension in 40 patients (15.6%), bradycardia in 23 (9.0%), or both in 28 (10.9%). Within a multivariable analysis adjusted for clinically relevant factors affecting rates of HD, the use of braided Elgiloy stents was associated with a decreased rate of procedural hypotension (odds ratio: 0.165; 95% confidence interval: 0.038, 0.721; P = .017). Procedural hypotension and bradycardia were not correlated to incidence of major adverse events but were associated with an increased duration of hospital stay (P = .0059 and P = .0335, respectively). CONCLUSIONS: Nitinol stents are associated with a higher risk of hypotension as compared to braided Elgiloy stents during carotid artery stent placement.

Clinical evaluation of the Zilver vascular stent for symptomatic iliac artery disease.

PURPOSE: To evaluate the safety and effectiveness of the Zilver vascular stent in the treatment of de novo or restenotic lesions in the external and common iliac arteries. MATERIALS AND METHODS: Regardless of the results of an initial percutaneous transluminal angioplasty (PTA), 151 consecutive patients were implanted with Zilver vascular stents (Cook, Bloomington, Ind) in up to two stenotic (< or =10 cm) or occluded (< or =5 cm) atherosclerotic lesions of the external or common iliac arteries. The primary endpoint was the rate of major adverse events within 9 months after the procedure. Major adverse events were defined as death, myocardial infarction, target lesion revascularization, and limb loss. Secondary endpoints included acute procedural success, 30-day clinical success, 9-month patency rate, 9-month functional status (on the basis of the validated Walking Impairment Questionnaire), and ankle-brachial index (ABI). RESULTS: of 1-, 6-, and 9-month follow-up are reported. Results The 9-month device and/or procedural-related major adverse event rate (adjudicated by an independent clinical events committee) was 2.7%. The all-cause major adverse event rate was 7.5%. Both rates were substantially below the prespecified objective performance criterion of 16%. The acute procedure success rate and 30-day clinical success rate were 98.0% and 94.0%, respectively. The 9-month patency rate, measured with duplex ultrasonography, was 92.9%. Significant improvement in the ABI and walking distance and walking speed scores, relative to preprocedural values, was seen at 1 month and was maintained through 9-month follow-up. CONCLUSIONS: The Zilver vascular stent is safe and effective as an adjunct to PTA in the treatment of symptomatic disease of the iliac arteries.

Bivalirudin as an anticoagulation agent: safety and efficacy in peripheral interventions.

PURPOSE: Traditionally, unfractionated heparin is used to prevent thrombotic complications in peripheral interventions. The purpose of this study is to evaluate the use of bivalirudin as the anticoagulant agent for peripheral interventions. MATERIALS AND METHODS: A retrospective analysis of 108 patients who underwent 110 peripheral interventions between January 2002 and January 2004 and received bivalirudin as the sole anticoagulation agent was conducted at Baptist Cardiac and Vascular Institute. Interventions were performed in the following areas: iliac, femoropopliteal, and distal (n = 55), carotid (n = 31), vertebral (n = 1), renal (n = 14), aorta (n = 7), and subclavian (n = 2). The following procedural and clinical endpoints were examined: death, requirement of urgent surgery or surgery during the same admission, urgent percutaneous revascularization in the same treated vessel, thrombotic or embolic events, bleeding events, and groin complications. RESULTS: A total of 266 lesions were dilated in 185 arteries. There were no procedural mortalities, procedural success was 99.1%, and the complication rate was 3.6%. There was one embolic stroke (0.9%), one thrombosis (0.9%), and two groin hematomas (1.8%). No patient required urgent surgery or reintervention in the same treated vessel. No complications were noted at 7 days after the procedure. There were two interventions by postprocedure day 30: toe amputation and groin debridement. CONCLUSION: Bivalirudin is a safe alternative to unfractionated heparin as the anticoagulation agent in peripheral interventions. This study shows that the complication profile is comparable to other bivalirudin studies. Bivalirudin is effective, easy to use, and is associated with few bleeding complications.

Delayed aortic aneurysm enlargement due to endotension after endovascular abdominal aortic aneurysm repair.

Abdominal aortic aneurysm (AAA) enlarges after successful endovascular repair, because of persistent blood flow within the aneurysm sac, or endoleak. In the absence of detectable endoleak, AAA may still expand, in part because of persistent pressurization within the excluded aneurysm, or endotension. We report three patients who underwent successful endovascular AAA repair in whom postoperative surveillance showed aneurysm regression, yet delayed AAA enlargement without demonstrable endoleak developed in all three patients. Endotension was confirmed in all three patients at elective open conversion. Our study underscores the significance of endotension as a mechanism of delayed aneurysm enlargement after successful endovascular AAA repair.

Implications of problematic access in transluminal endografting of abdominal aortic aneurysm.

PURPOSE: Despite careful preoperative assessment, problematic access to the abdominal aorta for transluminal endografting (TE) of abdominal aortic aneurysm (AAA) is sometimes encountered. This study identifies preoperative risk factors predictive of problematic access and determines the impact of problematic access on outcomes. MATERIALS AND METHODS: Three hundred twenty-one consecutive TE procedures for AAA were divided into two groups: group A, which had access problems (n = 74), and group B, which had none (n = 247). RESULTS: Logistic regression analysis of risk factors showed that (i) a pulmonary risk score of 3 (P <.001; odds ratio, 11.2), (ii) a hyperlipidemia score of 3 (P =.004; odds ratio, 2.6), and (iii) a small body (short height with low weight, P =.003; odds ratio, of 4.2) were independent risk factors for problematic access. Outcomes compared included rates of perioperative mortality, aborted procedure, surgical conversion, major complication, limb complication, and endoleak. The perioperative mortality rate was higher in group A (6.8% vs 1.2%; P =.018) and procedures were more likely to be aborted in patients in group A (12.2% vs 0%; P <.001). Rates of surgical conversion, major complication, and limb complication were not different between the two groups. The endoleak rate was higher in group B (10.8% vs 26.7%; P =.004). Logistic regression analysis showed that problematic access was an independent risk factor (P =.004; odds ratio, 12.0) for perioperative mortality. CONCLUSIONS: Moderate to severe chronic obstructive pulmonary disease and hyperlipidemia, both risk factors for atherosclerosis, were related to problematic access in this series. Small body size was another factor related to problematic access. Problematic access was an independent risk factor for perioperative mortality.