Predictors of Stroke, Myocardial Infarction or Death within 30 Days of Carotid Artery Stenting: Results from the International Carotid Stenting Study.

OBJECTIVES: Stroke, myocardial infarction (MI), and death are complications of carotid artery stenting (CAS). The effect of baseline patient demographic factors, processes of care, and technical factors during CAS on the risk of stroke, MI, or death within 30 days of CAS in the International Carotid Stenting Study (ICSS) were investigated. METHODS: In ICSS, suitable patients with recently symptomatic carotid stenosis > 50% were randomly allocated to CAS or endarterectomy. Factors influencing the risk of stroke, MI, or death within 30 days of CAS were examined in a regression model for the 828 patients randomized to CAS in whom the procedure was initiated. RESULTS: Of the patients, 7.4% suffered stroke, MI, or death within 30 days of CAS. Independent predictors of risk were age (risk ratio [RR] 1.17 per 5 years of age, 95% CI 1.01-1.37), a right-sided procedure (RR 0.54, 95% CI 0.32-0.91), aspirin and clopidogrel in combination prior to CAS (compared with any other antiplatelet regimen, RR 0.59, 95% CI 0.36-0.98), smoking status, and the severity of index event. In patients in whom a stent was deployed, use of an open-cell stent conferred higher risk than use of a closed-cell stent (RR 1.92, 95% CI 1.11-3.33). Cerebral protection device (CPD) use did not modify the risk. CONCLUSIONS: Selection of patients for CAS should take into account symptoms, age, and side of the procedure. The results favour the use of closed-cell stents. CPDs in ICSS did not protect against stroke.

Randomized clinical trial of stents versus angioplasty for the treatment of iliac artery occlusions (STAG trial).

BACKGROUND: The management of total iliac artery occlusion is now undertaken routinely using percutaneous techniques but there are no controlled data to indicate whether either balloon angioplasty or stent placement is preferable. This was a multicentre randomized trial to assess whether stents confer any safety or efficacy advantage over balloon angioplasty for complete iliac artery occlusion. METHODS: Six participating centres recruited patients with symptoms of lower limb peripheral arterial disease due to iliac artery occlusion 8 cm or less in length. Patients were assigned randomly to either percutaneous transluminal angioplasty (PTA group) or primary stent placement (stent group) alone after the lesion had been traversed with a guidewire. RESULTS: There were 118 patients recruited to the study; six were excluded from the analysis owing to major protocol violations, leaving a total of 112 patients for analysis. Some 55 patients had PTA and 57 had a primary iliac stent. Technical success was achieved in 46 patients (84 per cent) in the PTA group and 56 (98 per cent) in the stent group (P = 0.007). There were 11 (20 per cent) major procedural complications after PTA compared with three (5 per cent) after primary stenting (P = 0.010). There were no significant differences in primary or secondary patency between the groups after 1 and 2 years. CONCLUSION: Primary stent placement for iliac artery occlusion increased technical success and reduced major procedural complications (predominantly distal embolization) compared with balloon angioplasty. REGISTRATION NUMBER: ISRCTN 48145465 (http://www.controlled-trials.com).

United Kingdom carotid artery stent registry: short- and long-term outcomes.

BACKGROUND: Carotid artery stenting (CAS) has evolved to treat carotid artery disease with the intention of prevent stroke. The British Society of Interventional Radiologists developed a voluntary registry to monitor the practice of this novel procedure. We present the data from the United Kingdom (UK) CAS registry for short and long-term outcomes for symptomatic and asymptomatic carotid disease. METHODS: The UK CAS registry collected data from 1998 to 2010 from 31 hospitals across the UK for 1,154 patients. All interventions were enrolled in the registry for both asymptomatic and symptomatic patients. Initial entry forms were completed for each patient entered with data including indications, demographic data, CAS data (including stents and protection device details) and 30-day outcomes. Complications were documented. Follow-up data were collected at yearly intervals. RESULTS: Nine hundred fifty-three (83 %) symptomatic and 201 (17 %) asymptomatic patients were enrolled into the registry. The 30-day all stroke and death rates for symptomatic patients were 5.5 and 2.2 % for those with asymptomatic disease. The 30-day mortality rate was 1.7 % for symptomatic and 0.6 % for asymptomatic patients. For symptomatic patients undergoing CAS, the 7-year all-cause mortality rate was 22.2 % and for asymptomatic patients 18.1 %. The 7-year all-cause mortality and disabling stroke rates were 25.3 and 19.4 %, respectively. CONCLUSION: These data indicate that outside of the tight constraints of a randomised trial, CAS provides effective prophylaxis against stroke and death.

Patient-specific endovascular simulation influences interventionalists performing carotid artery stenting procedures.

OBJECTIVE: The ability to perform patient-specific simulated rehearsal of complex endovascular interventions is a technological advance with potential benefits to patient outcomes. This study aimed to evaluate whether patient-specific rehearsal of a carotid artery stenting (CAS) procedure has an influence on tool selection and the use of fluoroscopy. METHODS: Following case note and computed tomography (CT) angiographic review of a real patient case, subjects performed the CAS procedure on a virtual reality simulator. Endovascular tool requirements and fluoroscopic angles were evaluated with a pre- and post-case questionnaire. Participants also rated the simulation from 1 (poor) to 5 (excellent). RESULTS: Thirty-three endovascular physicians with varying degrees of CAS experience were recruited: inexperienced (5-20 CAS procedures) n = 11, moderately (21-50 CAS procedures) n = 7 or highly experienced (>50 CAS procedures) n = 15. For all participants, 96 of a possible 363 changes (26%) were observed from pre- to post-case questionnaires. This was most notable for optimal fluoroscopy C-arm position 15/33 (46%), choice of selective catheter 13/33 (39%), choice of sheath or guiding catheter 11/33 (33%) and balloon dilatation strategy 10/33 (30%). Experience with the CAS procedure did not influence the degree of change significantly (p > 0.05), and all groups exhibited a considerable modification in tool and fluoroscopy preference. The model was considered realistic and useful as a tool to practice a real case (median score 4/5). CONCLUSION: Patient-specific simulated rehearsal of a complex endovascular procedure strongly influences tool selection and fluoroscopy preferences for the real case. Further research has to evaluate how this technology may transfer from in vitro to in vivo and if it can reduce the radiation dose and the number of endovascular tools used and improve outcomes for patients in the clinical setting.

Patient-specific simulation for endovascular procedures: qualitative evaluation of the development process.

BACKGROUND: Recent advancements in simulation permit patient-specific rehearsal of carotid artery stenting procedures. This study evaluates the feasibility of transferring patient-specific CT data into the simulator, creating a 3D reconstruction and performing a rehearsal. The face validity of the model was assessed. METHODS/RESULTS: By thematic analysis of qualitative data, an algorithm was generated, focusing on simulation set-up, time of data transfer, software/compatibility issues and problem-solving strategies. The face validity of the simulated case was evaluated by 15 expert interventionalists: realism (median 4/5), training potential (median 4/5) and pre-procedure rehearsal potential for challenging CAS cases (median 4/5) were rated highly. CONCLUSIONS: Setting up a procedure rehearsal is feasible and reproducible for different patients in different hospital settings without major software compatibility issues. The time to create a 3D reconstruction of patient-specific CT data is a major factor in the total time necessary to set up a rehearsal. The face validity is highly rated by experts.

Who benefits most from intervention for asymptomatic carotid stenosis: patients or professionals?

Although there is level I evidence supporting the role of carotid endarterectomy (CEA) in patients with asymptomatic disease, opinion remains polarised regarding what constitutes optimal management, especially as carotid artery stenting (CAS) has emerged as a less invasive alternative. Reasons for this lack of consensus amongst surgeons, interventionists, neurologists and stroke physicians include our continued inability to identify 'high risk for stroke' patients in whom to target costly therapies. For example, recent data from the USA suggest that up to $21 billion is being spent each year on ultimately 'unnecessary' interventions. Second, is growing evidence that improvements in what now constitutes modern 'best medical therapy' has significantly reduced the risk of stroke compared to that observed in ACAS and ACST. If true, this will compromise risk:benefit analyses used in national and international guidelines. At a time when evidence suggests that up to 94% of interventions may not benefit the patient, the authors urge that at least one of the randomised trials comparing CEA with CAS in asymptomatic patients includes an adequately powered third limb for BMT. Timely investment now could optimise patient care and resource utilisation for all of us in the future.

The adjuvant benefit of angioplasty in patients with mild to moderate intermittent claudication (MIMIC) managed by supervised exercise, smoking cessation advice and best medical therapy: results from two randomised trials for stenotic femoropopliteal and aortoiliac arterial disease.

BACKGROUND: Uncertainty exists on whether there is adjuvant benefit of percutaneous transluminal angioplasty (PTA) over supervised exercise and best medical therapy in the treatment of intermittent claudication. METHODS: Patients with symptoms of stable mild to moderate intermittent claudication (MIMIC) were randomised in two multi-centre trials, for femoropopliteal and aortoiliac arterial disease, to receive either PTA or no PTA against a background of supervised exercise and best medical therapy and followed up for 24 months. Initial claudication distance (ICD) and absolute walking distance (AWD) on treadmill were compared between randomised groups adjusting for the corresponding measure at baseline. Secondary outcomes included ankle-brachial pressure index (ABPI) and quality of life. FINDINGS: A total of 93 patients were randomised into the femoropopliteal trial (48 into PTA) and 34 into the aortoiliac trial (19 to PTA). The mean (standard deviation, SD) age was 66(9) years for the femoropopliteal trial (63% male) and 63(9) for the aortoiliac trial (65% male). At 24 months, there were significant improvements in both AWD and ICD in the PTA groups for both trials. The adjusted AWD was 38% greater in the PTA group for the femoropopliteal trial (95%; CI 1-90) (p=0.04) and 78% greater in the PTA group for the aortoiliac trial (95%; CI 0-216) (p=0.05). Further benefits were demonstrated for ABPI but not for quality of life. INTERPRETATION: PTA confers adjuvant benefit over supervised exercise and best medical therapy in terms of walking distances and ABPI 24 months after PTA in patients with stable mild to moderate intermittent claudication.

Long-term retrievability of IVC filters: should we abandon permanent devices?

Thromboembolic disease produces a considerable disease burden, with death from pulmonary embolism in the UK alone estimated at 30,000-40,000 per year. Whilst it is unproven whether filters actually improve longevity, the morbidity and mortality associated with thromboembolic disease in the presence of contraindications to anticoagulation is high. Thus complications associated with filter insertion, and whilst they remain in situ, must be balanced against the alternatives. Permanent filters remain in situ for the remainder of the patient's life and any complications from the filters are of significant concern. Filters that are not permanent are therefore attractive in these circumstances. Retrievable filters, to avoid or decrease long-term filter complications, appear to be a significant advance in the prevention of pulmonary embolism. In this review, we discuss the safety and effectiveness of both permanent and retrievable filters as well as the retrievability of retrievable inferior vena cava (IVC) filters, to explore whether the use of permanent IVC filters can be abandoned in favor of retrievable filters. Currently four types of retrievable filters are available: the Recovery filter (Bard Peripheral Vascular, Tempe, AZ, USA), the Günther Tulip filter (Cook, Bloomington, IN, USA), the OptEase Filter (Cordis, Roden, The Netherlands), and the ALN filter (ALN Implants Chirurgicaux, Ghisonaccia, France). Efficacy and safety data for retrievable filters are as yet based on small series, with a total number of fewer than 1,000 insertions, and follow-up is mostly short term. Current long-term data are poor and insufficient to warrant the long-term implantation of these devices into humans. The case of fractured wire from a Recovery filter that migrated to the heart causing pericardial tamponade requiring open heart surgery is a reminder that any new endovascular device remaining in situ in the long term may produce unexpected problems. We should also bear in mind that the data on permanent filters are much more robust, with reports on over 9,500 cases with follow-up of up to 8 years. The original implantation time of 10-14 days has been extended to more than 100 days as the mean implantation time with some of the filter types. Follow-up (preferably prospective) is necessary for all retrievable filters, whether or not they are retrieved. Until these data become available we should restrict ourselves to the present indications of permanent and retrievable filters. If long-term follow-up data on larger numbers of cases confirm the initial data that retrievable filters are as safe and effective as permanent filters, the use of the retrievable filters is likely to expand.

Endovascular management of coarctation of the aorta.

Untreated thoracic aortic coarctation leads to early death predominantly because of hypertension and its cardiovascular sequelae. Surgical treatment has been available for > 50 years and has improved hypertension and survival. More recently, endovascular techniques have offered a minimally invasive alternative to traditional open repair. Early and intermediate results suggest angioplasty and stenting have an important role in the management of aortic coarctation, particularly in adults and older children.

The evidence for carotid stenting versus carotid endarterectomy in symptomatic patients.

Large randomized trials have demonstrated the value of surgical intervention for symptomatic carotid artery disease in stroke prevention. More recently trials have also demonstrated benefit in asymptomatic patients. However, the benefit of surgery comes with significant burden in terms of a risk of both stroke at the time of procedure and other complications. Less invasive endovascular techniques might reduce this complication rate whilst proving as effective as surgery. At the time of writing conclusive evidence is still being sought but a Cochrane meta-analysis has indicated that with the current knowledge based on randomised trials the neuro-embolic complication rate at 30 days is equivalent between the two therapies. Endovascular techniques have fewer non-neuroembolic complications.

Safety of arch aortography for assessment of carotid arteries.

PURPOSE: To retrospectively review the safety of arch aortography and compare complication rates with published figures for selective catheter angiography. METHODS: The medical records of patients undergoing arch aortography over the last 3 years (n=311; 180 male, 131 female; mean+/-SD age 71.0+/-9.2 years, range 42-90 years) were retrospectively reviewed. Any peri-procedural (0-48 h) complications were recorded. A certified neurologist (MSR/GSV) classified all questionable neurological events. RESULTS: There were no focal neurological events or deaths (n=0; 0%; CI: 0-0.96%). Non-focal neurological events included mild disorientation (n=2; 0.6%; CI: 0.176-2.31) and unequal pupils (n=1; 0.3%; CI: 0.056-1.79%). Cardiovascular events included symptomatic hypotension (n=4; 1.3%; CI: 0.50-3.25%), angina (n=1; 0.3%; CI: 0.056-1.79%) and arrhythmia (n=4; 1.3%; CI: 0.50-3.25). There were 27 minor access site complications (8.7%; CI: 6.0-12.3). None of these complications extended hospital stay. None of the arch angiograms had to be followed by selective carotid angiography. CONCLUSION: Arch aortography appears to have a lower neurological complication rate than selective carotid angiography.

The benefits of combined anti-platelet treatment in carotid artery stenting.

OBJECTIVE: To assess the benefits of a combined anti-platelet regime of aspirin and clopidogrel in carotid artery stenting. METHODS: A randomised controlled trial was performed comparing aspirin and 24-h heparin with aspirin and clopidogrel for patients undergoing carotid artery stenting. Outcome measures included 30-day bleeding and neurological complications and 30-day stenosis rates. RESULTS: Bleeding complications (groin haematoma or excessive bleeding at the groin site) occurred in 17% of the heparin and 9% of the clopidogrel group (p=0.35; n.s). The neurological complication rate in the 24-h heparin group was 25% compared to 0% in the clopidogrel group (p=0.02). The 30-day 50-100% stenosis rates were 26% in the heparin group and 5% in the clopidogrel group (p=0.10; n.s). CONCLUSIONS: The dual anti-platelet regime has a significant impact on reducing adverse neurological outcomes without an additional increase in bleeding complications. This study was terminated prematurely due to an unacceptable level of complications in the heparin arm of the trial.

Endoluminal repair of anastomotic false popliteal aneurysm using the Wallgraft endoprosthesis.

The aim of this study was to present the endoluminal repair of a false anastomotic popliteal aneurysm on a previous polytetrafluoroethylene (PTFE) above knee bypass using a Wallgraft endoprosthesis. A 53-year-old man who underwent a left femoro-popliteal above knee PTFE bypass 13 years before was admitted with a painful pulsatile mass in the above knee area. Nine months previously he developed sudden pain around the knee extending to the foot associated with coldness and numbness after he was handling some fishing gear in a crouching position for about 1 hour, but this episode spontaneously resolved. Duplex scanning and angiography revealed a 3 x 2.5 cm false aneurysm, which was successfully treated by deploying a Wallgraft endoprosthesis as the patient declined surgical repair. The graft was detected as being occluded on the 3-month follow-up but no further action was taken because the patient experienced only non-limiting claudication and he refused again surgical treatment. Endoluminal repair of perianastomotic false aneurysms in the popliteal artery with Wallgraft endoprosthesis seems feasible and safe, but until its durability is validated in larger series surgical repair remains the treatment of choice.

A multicentre evaluation of the Medtronic AVE Flexible Iliac Bridge Stent in the iliac arteries (the first study).

PURPOSE: To investigate the short term and 6 month outcomes of a recently introduced iliac stent (the Medtronic AVE Flexible Iliac Bridge Stent). METHOD: One hundred and sixteen patients, 122 limbs from 6 European sites with atherosclerotic occlusive disease were included if they either had a full occlusion or there was a residual gradient >10 mmHg following PTA. Clinical, haemodynamic and Duplex outcomes were recorded to 6 months. RESULTS: After stent placement there was no residual stenosis >30 and 8.1% of segments had a residual resting gradient of >10 mmHg. There were three local complications and three deaths at 30 days. Primary patency at 30 days and 6 months was 94.1 and 82.7%. Marked clinical improvement occurred in 87.6 and 86.2% at 30 days and 6 months. CONCLUSION: The Medtronic AVE iliac stent has good 30 day and 6 months outcomes supporting the effective use of this device in occlusive disease.

Is the endovascular treatment of carotid stenosis in high-risk patients really safer than carotid endarterectomy?

BACKGROUND: We assess the outcomes of patients who would have been considered at high-risk from carotid endarterectomy (CEA), who have undergone endovascular treatment. METHODS: High-risk patients were classed as those with occlusion of the contralateral internal carotid artery, recurrent stenosis following CEA, stenosis secondary to neck irradiation or treatment prior to coronary bypass surgery. RESULTS: 103 procedures fulfilled at least one inclusion criterion. 58.3% had symptomatic disease. The all stroke/death rate was 9.7%. The major disabling stroke/stroke-related death rate was 3.9%. 63 had a contralateral occlusion, 15 post-CEA, 17 post-radiation and 33 pre-coronary surgery. The major disabling stroke/stroke-related death rates for each subset were 4.8, 6.7, 0 and 0%, respectively. CONCLUSIONS: These results suggest that this category of patients is at high-risk of stroke regardless of method of carotid intervention.

Complications following carotid angioplasty and carotid stenting in patients with symptomatic carotid artery disease.

BACKGROUND: We review a single centre's experience of the endovascular treatment of carotid artery disease, present the 30-day and 1-year complication rates and assess whether changes in technique are associated with a change in clinical outcome. METHODS: Patients who underwent carotid angioplasty with or without stenting for symptomatic > or = 70% carotid artery stenosis secondary to atherosclerosis were included. 333 procedures were performed, i.e. angioplasty alone (86), stent without cerebral protection (150) and stent with cerebral protection (97). RESULTS: At 30 days, the total major disabling stroke and all death rate was 3.0%. For angioplasty alone, this was 2.3%, for stent without cerebral protection 4.0% and for stent with cerebral protection 2.1%. If non-stroke-related deaths were excluded, it was 2.3, 3.3 and 0%, respectively. After 30 days, the 1-year ipsilateral stroke rate was 0.8%. CONCLUSIONS: Carotid artery stenting, in particular with a cerebral protection device, is a safe alternative to carotid endarterectomy for the treatment of symptomatic high-grade carotid artery disease.

Effect of treatment of carotid artery stenosis on blood pressure: a comparison of hemodynamic disturbances after carotid endarterectomy and endovascular treatment.

BACKGROUND AND PURPOSE: Carotid intervention by carotid endarterectomy (CEA) or endovascular treatment may cause hemodynamic change. The immediate and long-term effects on blood pressure after these procedures were assessed. METHODS: Patients were randomized to CEA (n=49) or endovascular treatment (n=55) that comprised percutaneous transluminal angioplasty alone (n=31), balloon-expandable stent (n=13), or self-expandable stent (n=11). A baseline 24-hour ambulatory blood pressure recording was made before carotid intervention and repeated at 24 hours, 1 month, and 6 months after the procedure. RESULTS: In the first 24 hours after the procedure, episodes of hypotension occurred in 75% of the CEA group and 76% of the endovascular group; hypertension occurred in 11% and 13%, respectively. There was a significant fall in blood pressure at 1 hour after the procedure in both groups (24 and 16 mm Hg fall in CEA and endovascular groups, respectively), but this was only sustained in the endovascular group. The pattern of blood pressure response in the first 24 hours was significantly different (P<0.0001, ANCOVA). Systolic blood pressure was significantly lower at 1 and 6 months only in the surgical group (6 and 5 mm Hg fall, respectively). CONCLUSIONS: Both CEA and endovascular treatment have an effect on blood pressure stability, particularly within the first 24 hours after the procedure.