Benefits of cerebral protection during carotid stenting with the PercuSurge GuardWire system: midterm results

Safety and Risk Factors of Carotid Artery Stenting with Simple Distal Filter Protection: A Single-Center Retrospective Study

Objective

Carotid artery stenting embolic protection devices offer various options, among which distal filter protection is the simplest and easiest to handle. However, compared to balloon protection systems, distal filter protection has more embolic complications. Therefore, we explored the risk factors of distal filter protection, intending to achieve a safer carotid artery stenting. This retrospective study was conducted to identify prognostic factors following carotid artery stenting with only distal filter protection from July 2010 to June 2021.

Methods

Information on patient background, procedures and devices, and complications was collected using medical records. The data pertaining to 187 patients were analyzed after excluding the data of patients in whom other protection devices (8 cases) were used. We used FilterWire EZ as the first choice for embolic protection device and SpiderFX when the patients had difficult-to-cross lesions.

Results

The patients' mean age was 71.9 ± 6.9 years, and 72 (38.5%) were symptomatic. Symptomatic (odds ratio: 2.02, p = 0.035) and difficult-to-cross lesions (odds ratio: 3.63, p = 0.0013) were factors independently associated with symptomatic complications.

Conclusion

This retrospective single-center study established independent prognostic factors for carotid artery stenting with distal filter protection. For patients with symptomatic lesions and severe stenosis or bends that are difficult to pass through, it is necessary to be careful when performing carotid artery stenting with distal filter protection.

Carotid Stenting for Radiation-Induced Extracranial Carotid Artery Occlusive Disease: Efficacy and Midterm Outcomes

Purpose:

To investigate the immediate and midterm results of carotid stenting for severe radiation-induced extracranial carotid artery disease.

Methods:

Between April 1998 and May 2002, 16 patients (15 men; mean age 64±8 years, range 48–72) presented with 18 severe radiation-induced carotid stenoses in the internal carotid artery (n=3), common carotid artery (n=7), and both vessels (n=8). Thirteen (76%) patients were symptomatic; the mean degree of carotid stenosis was 85%±10% (range 70%–95%). An independent neurological specialist assessed perioperative neurological complications before and after treatment. The patients were followed prospectively for at least 12 months by clinical examination and serial duplex ultrasound scanning. Restenosis was defined as a diameter reduction >50%.

Results:

Of 18 stent procedures attempted (2 staged), 1 was abandoned owing to failure to pass the guidewire across a tight lesion (94% technical success by intent to treat). In the 17 successfully completed procedures, 17 Wallstents and 4 SMART stents were deployed with satisfactory anatomical results. One postoperative stroke occurred as a result of thromboembolism to the ipsilateral middle cerebral artery and led to hospital death (5.9% combined stroke and death rate). One transient ischemic attack occurred (11.6% neurological event rate). With a median 30-month follow-up (range 5–55), 3 (17.6%) recurrent stenoses (>50%) were detected on duplex scan; 1 repeat angioplasty was performed. No new neurological event has been detected.

Conclusions:

Carotid stenting may be performed in patients with irradiation-induced carotid stenosis with acceptable risks and midterm durability.

Atheromatous embolization

Atheromatous embolization is a multisystem disease complicating advanced atherosclerosis. It occurs most often as a complication of angiography, an endovascular procedure or cardiovascular surgery. Atheromatous embolization can present in a subtle manner where it is often under-recognized, or with catastrophic results including myocardial infarction, strake or acute renal failure. It may mimic other disease processes and often goes underdiagnosed and undertreated. A high clinical suspicion is the key to diagnosis. Atheromatous embolization results in significant morbidity and mortality; therefore, early recognition followed by aggressive management may help to prevent end-organ damage and improve overall clinical outcomes. Management strategies should include risk factor modification, prevention of further insults by discontinuing or avoiding predisposing factors, supportive treatment and interventional or surgical approaches to remove the atheroembolic source. Atheromatous embolization is expected to increase as our population ages and the epidemics of diabetes mellitus and obesity increase.

Double balloon protection during carotid artery stenting for vulnerable carotid stenosis reduces the incidence of new brain lesions

BACKGROUND

The use of distal filter protection alone is associated with a high risk of ischemic complications when vulnerable carotid stenosis is treated by carotid artery stenting (CAS). Double balloon protection, a combination of distal balloon protection and proximal balloon occlusion, can be utilized. We assessed the outcome and complications of the double balloon protection method for vulnerable carotid stenosis.

METHODS

Among 130 patients who underwent CAS from 2009 to 2014, we enrolled the following patients: those whose target lesion was vulnerable as evaluated by MRI, i.e., a signal ratio of plaque to posterior cervical muscle on T1-weighted images before CAS of ≥1.5, and those who underwent diffusion-weighted imaging (DWI) studies within 48 h after the procedure. Ninety patients were enrolled. We investigated DWI findings of the double balloon protection group compared with those of the simple distal balloon protection and distal filter protection groups.

RESULTS

Sixty-four patients (71 %) underwent double balloon protection, 15 patients (17 %) simple distal balloon protection, and 11 patients (12 %) distal filter protection. Symptomatic embolic complications and new lesions on DWI after CAS were significantly less common in patients undergoing double balloon protection compared to distal balloon protection or distal filter protection (0 % vs. 20 %, 9 %, P < 0.01, and 30 % vs. 67 %, 82 %, P < 0.01, respectively). Logistic regression analysis also identified the odds ratio of double balloon protection for new lesions on DWI after CAS of 0.23 (95 % confidence interval: 0.07-0.70, P < 0.01) compared to simple distal protections.

CONCLUSIONS

In the patients who underwent CAS for vulnerable carotid stenosis, double balloon protection was an independent significant factor associated with a reduction in the risk of new lesions on DWI after the procedure compared to conventional distal protections.

Belgian Experience with FilterWire EX in the Prevention of Embolic Events during Carotid Stenting

Purpose:

To evaluate the performance of the FilterWire EX for the capture and removal of debris and prevention of embolic events during endovascular carotid interventions.

Methods:

In the period from October 2001 to May 2002, 100 patients (60 men; mean age 72 years, range 48–90), 69 symptomatic with >50% internal carotid artery (ICA) stenosis and 31 asymptomatic with >70% stenosis were scheduled for carotid stenting with cerebral protection provided by the FilterWire EX system. Satisfactory performance of the filter was defined as effectiveness in preventing intraprocedural embolic events shown by visible debris in the filter and unchanged neurological status assessed by an independent neurologist.

Results:

The placement and retrieval of the FilterWire EX was technically successful in 93 of 100 patients. Five delivery failures were due to severe ICA angulation; one stenosis was underestimated on preprocedural imaging, and one case was aborted following a major stroke during sheath manipulation before filter introduction. In 56.9% of the protected cases, the filter contained debris. One neurological event occurred 6 hours after the procedure: a transient ischemic attack from which the patient recovered fully after 2 hours. No other procedure-related events were recorded within 30 days of the procedure. The procedural success among the 93 patients stented under FilterWire EX protection was 98% (92% by intention to treat).

Conclusions:

The FilterWire EX appears to be an effective tool in the prevention of embolic events and in preserving neurological status during endovascular treatment of carotid artery stenosis.

Carotid Revascularization Using Endarterectomy or Stenting Systems (CARESS): Phase I Clinical Trial

Purpose:

To determine whether carotid stenting with embolic protection is equivalent to carotid endarterectomy (CEA) in a broad risk population of patients with symptomatic and asymptomatic carotid stenosis.

Methods:

A prospective, multicenter Phase I trial was conducted comparing standard CEA to carotid stenting systems (CSS) in patients with symptomatic (≥50%) and asymptomatic (≥75%) carotid stenosis. Patients were enrolled using selection criteria reflective of broad clinical practice. The enrollment ratio at each clinical site was designed to be 2:1 (CEA to CSS) to achieve a planned enrollment of 450 patients: 300 in the CEA arm and 150 in the CSS cohort, which would ensure adequate precision with a coefficient of variation ≤0.35. The primary endpoint for comparison was 30-day all-cause mortality and nonfatal stroke.

Results:

Between April 2001 and December 2002, 14 clinical sites enrolled 439 patients, of which 397 (247 men; mean age 71 years, range 44–89) were treated: 254 with CEA and 143 patients with CSS (ratio 1.8 to 1.0). More than 90% of patients had >75% stenosis; ∼68% of patients were asymptomatic. There were no significant differences in baseline patient characteristics between the treatment groups with the exception of a more frequent history of prior CEA (30% CSS versus 11% for CEA, p<0.0001) and prior carotid stent placement in the CSS group (6% versus 0% for CEA, p = 0.0002). There was no significant difference in the 30-day combined all-cause mortality and stroke rate by Kaplan-Meier estimate between CEA (2%) and CSS (2%). There was no significant difference in the secondary endpoint of combined 30-day all-cause mortality, stroke, and myocardial infarction between CEA (3%) and CSS (2%).

Conclusions:

This study suggests that the 30-day risk of stroke or death following carotid stenting with cerebral protection is equivalent to standard carotid endarterectomy in a broad risk population of patients with carotid stenosis.

Periprocedural outcomes after surgical revascularization and stenting for postradiotherapy carotid stenosis

BACKGROUND

Treatment of head and neck malignancy commonly involves radiotherapy, which is associated with the development of carotid artery stenosis. There is little evidence to guide clinicians on how to intervene in significant postradiotherapy carotid stenosis. This systematic review collated data pertaining to perioperative outcomes of carotid artery surgery and carotid stenting in postradiotherapy carotid stenosis to aid the clinical decision-making process.

METHODS

A systematic review of the literature, adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2009 guidelines, was performed. We screened 575 articles related to carotid artery surgery or stenting in postradiotherapy carotid stenosis, from which 21 studies were included for quantitative analysis. The primary outcome was stroke or death ≤ 30 days of the procedure. Secondary outcomes included cranial nerve injury, restenosis, stroke, and death at >30 days.

RESULTS

Nine publications recorded 211 surgical procedures in 179 patients. In symptomatic patients, the 30-day mortality rate was 2.6% and the stroke or death rate was 2.7%. In asymptomatic patients, the 30-day mortality rate was 0% and the stroke or death rate was 1.1%. Permanent cranial nerve palsy was experienced by 0.6% of patients. Twelve publications recorded 510 carotid artery stenting procedures in 482 patients. In symptomatic patients, the 30-day mortality rate was 5.1%, and the stroke or death rate was 5.1%. In asymptomatic patients, the 30-day mortality rate was 1.4%, and the stroke or death rate was 2.1%. There was no statistically significant difference in 30-day stroke or death rate between surgical revascularization and carotid artery stenting in all (odds ratio [OR], 0.54; 95% confidence interval [CI] 0.17-1.70; P = .43), symptomatic (OR, 0.52; 95% CI, 0.14-1.98; P = .38), or asymptomatic patients (OR, 0.55; 95% CI, 0.06-5.42; P = .99).

CONCLUSIONS

The published outcomes from high-volume centers demonstrate that surgical revascularization and stenting are both technically feasible in postradiotherapy carotid stenosis and have similar safety profiles to nonirradiated necks. Radiation should therefore not be considered a contraindication to surgical intervention.

Embolic complications after carotid artery stenting or carotid endarterectomy are associated with tissue characteristics of carotid plaques evaluated by magnetic resonance imaging

BACKGROUND

Unstable carotid plaques are associated with an increased incidence of embolic complications after carotid artery stenting (CAS) or carotid endarterectomy (CEA). The aim of this study was to elucidate the relationship between the tissue components of carotid plaques and the incidence of new ipsilateral silent ischemic lesions (NISIL) after CAS or CEA.

METHODS

We performed CAS in 56 patients and CEA in 25 patients. We also performed quantitative analyses of carotid plaque characteristics before treatment using T1 weighted black-blood magnetic resonance imaging (BB-MRI). The signal intensity ratio (SIR) was defined as the ratio of signal intensity evaluated by BB-MRI in carotid plaques to that of sternocleidomastoid muscle. According to criteria that we and other investigators previously reported, an SIR ≥ 1.25 was defined as "high". NISIL were evaluated by diffusion-weighted imaging of MRI before and after CAS or CEA.

RESULTS

In the high SIR group, the incidence of NISIL was significantly greater after CAS than after CEA (61% vs 13%, respectively, p=0.006), whereas there were no significant difference in NISIL after the two procedures when the SIR was <1.25 (21% vs 0%). In multivariate regression analysis, the independent predictors of NISIL were CAS (p=0.002), symptomatic stenosis (p=0.036) and the SIR (p=0.049).

CONCLUSIONS

Noninvasive quantitative tissue characterization of carotid plaques using BB-MRI is useful to determine the indication for CAS.

Predictors of embolization during protected renal artery angioplasty and stenting: Role of antiplatelet therapy

OBJECTIVE

The objective of this study was to identify the predictors of distal embolization (DE) during protected renal artery angioplasty and stenting.

BACKGROUND

DE may contribute to worsening renal function after renal artery stenting. The factors associated with DE, rates of platelet-rich emboli, and treatments that may prevent DE during renal stenting have not been evaluated.

METHODS

The current study evaluated patients randomized to receive an embolic protection device (EPD) in the RESIST trial. Forty-two patients were identified for inclusion in this study. These patients were further randomized to abciximab (N = 22) or placebo (N = 20). Modification in Diet in Renal Disease glomerular filtration rate (GFR) was used as the primary measure of renal function. Creatinine was measured by a modified Jaffe reaction using the IDMS-traceable assay. The primary endpoint was capture of platelet rich emboli in the angioguard basket.

RESULTS

DE occurred in 15/42 (35%) of the patients and platelet rich DE in 10 (24%) of the patients who received an EPD. Of the angiographic characteristics only lesion length was significantly higher in patients with DE (16 +/- 7 mm vs. 10 +/- 5 mm, P = 0.04). Preprocedural abciximab reduced DE from 42 to 8% (P = 0.02). The rate of platelet rich emboli was 50% with neither abciximab nor a thienopyridine, 36% with thienopyridine only, 15% abciximab only, and 0% in patients who received both a thienopyridine and abciximab. Only Abciximab use was associated with improved renal function at 1-month, thienopyridine was not. Angiographic characteristics including percent stenosis, minimal luminal diameter (MLD), reference diameter, change in MLD, contrast volume, and procedure time were not predictors of DE during renal stenting.

CONCLUSION

Capture of DE and specifically platelet DE are common during protected renal stenting using a filter-type EPD. Abciximab use, and potentially combined thienopyridine and abciximab use, decreased the rate of platelet rich DE; however, only abciximab improved renal function at 1-month.

In stent restenosis predictors after carotid artery stenting

Purpose. The long-term efficacy of carotid artery stenting is debated. Predictors of stent restenosis are not fully investigated. Our aim was to assess the incidence of long term restenosis after CAS and to identify some predictors of restenosis. Methods. We retrospectively selected 189 treated patients and we obtained the survival Kaplan-Meier curves for overall survival, for freedom from stroke or death and from restenosis. To correlate clinical, radiological, and procedural variables to stent restenosis, an univariate analysis was performed while to determine independent predictors of restenosis, a multivariate analysis was applied. Results. At 1, 3, and 5 years, the cumulative overall survival rate was 98%, 94%, and 92% with a cumulative primary patency rate of 87%, 82.5%, and 82.5%. The percentage residual stenosis after CAS and multiple stents deployment were independent predictors of restenosis, while diabetes and tumors are suggestive but not significant predictors of restenosis. Conclusions. In our CAS experience, encouraging long-term results seem to derive from both neurological event free rate and restenosis incidence. Adequate recanalization of the treated vessel is important to limit the development of stent restenosis. Multiple stents deployment, and with less evidence, diabetes, or neoplasms has to be considered to facilitate restenosis.

How to avoid complications associated with carotid angioplasty and stenting

Carotid angioplasty and stenting (CAS) has been proposed as an alternative to surgery and is now performed more frequently and is well accepted, at least for high surgical risk patients. However, complications and particularly embolic strokes, even with a meticulous technique, can occur at any step of the procedure. Silent embolism is detected after CAS and may be a problem that needs to be discussed. To avoid and reduce these complications associated with CAS, it is important to have good indications dependent upon on good patient and lesions selection, as well as correct technique. New parameters have been proposed, particularly for asymptomatic lesions. The authors consider that embolic protection devices (EPDs) are mandatory for CAS, and new techniques will be presented. The choice of the EPD depends on the clinical status of the patient, the lesion morphology and characteristics, and the anatomy of the artery. All stents are not equivalent and so a good choice of the stent is necessary to avoid and reduce the complications associated with CAS, and experienced operators are also needed. With all these considerations, CAS can now be performed with acceptable outcomes and in certain population the results are comparable or superior to surgery. The results of ongoing randomized trials are awaited.

Use of a guide wire system to insert guiding catheters

In patients with severe arteriosclerosis or anatomical variations such as a bovine arch, the insertion of a guiding catheter for carotid artery stenting is difficult. The authors use a guide wire system as an anchor and advance the guiding catheter to an area proximal to the stenotic structure. This method is useful and safer than others for carotid artery stenting.

Analysis of cerebral perfusion and metabolism assessed with positron emission tomography before and after carotid artery stenting. Clinical article

OBJECT

The authors analyzed cerebral perfusion and metabolism in patients with internal carotid artery stenosis before and after carotid artery stenting (CAS).

METHODS

Sixteen patients with internal carotid artery stenosis (>70%) underwent PET scanning before CAS, 1-7 days after CAS, and 3-4 months after CAS to assess a variety of parameters related to cerebral perfusion and metabolism.

RESULTS

Cerebral blood flow at rest (CBFrest) significantly increased in the immediate postoperative stage before returning to normal levels over the long term; this trend was also recognized on the contralateral side. In contrast, there was gradual improvement in the rate of CBF variation on acetazolamide administration (% CBFaz). Cerebral perfusion pressure (CBF/cerebral blood volume) increased rapidly during the acute stage and decreased in the long term, and the oxygen extraction fraction decreased slightly during the acute stage before normalizing over the long term. The cerebral metabolic rate of oxygen (CMRO2) increased slightly after stenting over both the short and long term. The ratios of ipsilateral to contralateral values (asymmetry index) for CBFrest, % CBFaz, cerebral blood volume, oxygen extraction fraction, and CMRO2 tended to approach 1.0 over time.

CONCLUSIONS

Repeated PET scanning revealed improvements in CBF, perfusion pressure, and oxygen metabolism after CAS. In particular, the vascular reserve tended to improve gradually, while CBF, cerebral perfusion pressure, and CMRO2 increased rapidly and peaked soon after CAS. These results suggest that a large discrepancy between rapidly increased CBF, perfusion pressure, and a small increase in vascular reserve in the acute stage after CAS could cause hyperperfusion syndrome.

Do the Advantages of the FiberNet(®) Embolic Protection Device Translate into Technical Success and Comparable Event Rates in Carotid Artery Stenting?

FiberNet(®) is a second generation non-conventional embolization protection device (EPD) that purports to offer several advantages: ability to capture debris as small as 40 μm, more flexibility with placement and positioning in curved segments requiring a small landing zone, ability to conform to asymmetric vessels, and improved deliverability. The design features a low profile with large surface area to capture debris. Legitimate concerns include inducement of obstruction or low flow with debris capture and requirements in the IFU to aspirate during re-capture and device removal. Our goal was to compare the results of carotid artery stenting (CAS) using FiberNet(®) against a multi-center experience of CAS using other filter devices to identify any differences in technical success or event rates. FiberNet(®) (n=25) results were compared to all CAS cases performed at the Mayo Clinic in Rochester, MN, St Mary's/Duluth Clinic in MN, and North Central Heart Institute in Sioux Falls, SD (n=250) from March 2001 to December 2008. Chi-square or means were used to compare variables, as appropriate. Bivariate logistic regression was used to identify possible correlates of adverse outcome. Statistical significance was set at < 0.05. FiberNet(®) patients were more likely to be older (78.1+5.4 vs 73.6+9.4, p=0.019), female (48% vs 29%, p=0.047), and have peripheral vascular disease (84.0% vs 37.2%, p=0.025), and less likely to have diabetes (8.0% vs 29.8%, p=0.012) than patients in the comparison group. FiberNet(®) patients had more lesion calcification (40.0% vs 18.9%, p=0.014) and increased number of type 2 and 3 arches (44.2% vs 73.9%, p=0.006). Procedural success rate was 100% in both groups. None of the FiberNet(®) patients showed evidence of stagnant flow. The thirty-day outcome for TIA, CVA, or death was 4% in FiberNet(®) versus 4.8% in the comparison group (p NS). None of the independent variables - age gender, serum creatinine, arch complexity, lesion length, lesion calcium, lesion thrombus, PVD, diabetes, contralateral carotid occlusion, or ipsilateral carotid endarterectomy - predicted adverse events. Although FiberNet(®) patients had more lesion calcium and more challenging arch anatomy, procedural success and adverse events were comparable between groups. The advantages of FiberNet(®) can be applied to CAS with good technical results and may be a promising EPD for certain high-risk situations.

Ischemic preconditioning during the use of the PercuSurge occlusion balloon for carotid angioplasty and stenting

Ischemic preconditioning (IP) uses transient ischemia to render tissues tolerant to subsequent, prolonged ischemia. This study sought to evaluate factors that contributed to the development of cerebral ischemia during PercuSurge balloon (Medtronic, Santa Rosa, CA) occlusion in patients undergoing carotid angioplasty and stenting (CAS). The PercuSurge occlusion balloon was used in 43 of 165 patients treated with CAS for high-grade stenosis; 20% were symptomatic. Symptoms of cerebral hypoperfusion during temporary occlusion of the internal carotid artery occurred in 10 of 43 patients and included dysarthria, agitation, decreased level of consciousness, and focal hemispheric deficit. The development of neurologic symptoms after initial PercuSurge balloon inflation and occluded internal carotid artery flow was associated with a decrease in the mean Glasgow Coma Scale (GCS) from 15 to 10 (range 9-14); the GCS returned to normal after occlusion balloon deflation. The mean time to spontaneous recovery of full neurologic function was 8 minutes (range 4-15 minutes). The mean subsequent procedure duration was 11.9 minutes (range 6-21 minutes). No recurrence of neurologic symptoms occurred when the occlusion balloon was reinflated. All 10 patients underwent successful CAS without occlusion, dissection, cerebrovascular accident, or death. Ischemic preconditioning can be used to enable CAS with embolic protection in patients who cannot tolerate initial interruption of antegrade cerebral perfusion by PercuSurge occlusion.

Characterization of carotid atherosclerosis and detection of soft plaque with use of black-blood MR imaging

BACKGROUND AND PURPOSE

In the treatment of carotid atherosclerosis, the rate of stenosis and characteristics of plaque should be assessed to diagnose vulnerable plaques that increase the risk for cerebral infarction. We performed carotid black-blood (BB) MR imaging to diagnose plaque components and assess plaque hardness based on MR signals.

MATERIALS AND METHODS

Three images of BB-MR imaging per plaque were obtained from 70 consecutive patients who underwent carotid endarterectomy (CEA) to generate T1- and T2-weighted images. To evaluate the relative signal intensity (rSI) of plaque components and the relationship between histologic findings and symptoms, we prepared sections at 2-mm intervals from 34 intact plaques. We then calculated the relative overall signal intensity (roSI) of 70 plaques to assess the relationship between MR signal intensity and plaque hardness and symptoms.

RESULTS

The characteristics of rSI values on T1- and T2-weighted images of fibrous cap (FC), fibrosis, calcification, myxomatous tissue, lipid core (LC) with intraplaque hemorrhage (IPH), and LC without IPH differed. Symptomatic plaques were associated with FC disruption (P < .001) and LC with IPH (P < .05). The roSI on T1-weighted images was significantly higher for soft than nonsoft plaques. When the roSI cutoff value was set at 1.25 (mean of the roSI), soft plaques were diagnosed with 79.4% sensitivity and 84.4% specificity. The roSI was also significantly higher for symptomatic than for asymptomatic plaques. Soft and nonsoft plaques as well as symptomatic and asymptomatic plaques did not significantly differ on T2-weighted images.

CONCLUSION

BB-MR imaging can diagnose plaque components and predict plaque hardness. This procedure provides useful information for planning therapeutic strategies of carotid atherosclerosis.

Carotid intervention 3: the evidence for cerebral protection

Carotid stenting is a safe alternative option to conventional carotid endarterectomy in the treatment of carotid artery stenosis in patients considered poor candidates for surgery or who choose not to have open surgery. During the stenting procedure, however, distal embolization may occur with neurological sequelae. To reduce the incidence of this, several cerebral-protection devices (CPDs) have been developed. Different types of CPDs are now commercially available: distal occlusion balloons, distal filters, and proximal protection devices with or without reversal of flow. But complications can occur with their use and are usually associated with an inability to cross the lesion, failure to capture the emboli, vasospasm, and vessel wall injury. Because protection devices are currently the focus of interest by manufacturers and physicians, several trials are going on worldwide to analyze the characteristics of each of them and to evaluate their efficacy in reducing the rate of distal embolization.

Methods for Three-Dimensional Geometric Characterization of the Arterial Vasculature

Complex vascular anatomy often affects endovascular procedural outcome. Accurate quantitative assessment of three-dimensional (3D) in-vivo arterial morphology is therefore vital for endovascular device design, and preoperative planning of percutaneous interventions. The aim of this work was to establish geometric parameters describing arterial branch origin, trajectory, and vessel curvature in 3D space that eliminate the errors implicit in planar measurements. 3D branching parameters at visceral and aortic bifurcation sites, as well as arterial tortuosity were determined from vessel centerlines derived from magnetic resonance angiography data for three subjects. Errors in coronal measurements of 3D branching angles for the right and left renal arteries were 3.1 +/- 3.4 degrees and 7.5 +/- 3.7 degrees , respectively. Distortion of the anterior visceral branching angles from sagittal measurements was less pronounced. Asymmetry in branching and planarity of the common iliac arteries was observed at aortic bifurcations. The renal arteries possessed considerably greater 3D curvature than the abdominal aorta and common iliac vessels with mean average values of 0.114 +/- 0.015 and 0.070 +/- 0.019 mm(-1) for the left and right, respectively. In conclusion, planar projections misrepresented branch trajectory, vessel length, and tortuosity proving the importance of 3D geometric characterization for possible applications in planning of endovascular interventional procedures and providing parameters for endovascular device design.

Transcervical carotid stenting with flow reversal for neuroprotection: technique, results, advantages, and limitations

Carotid angioplasty and stenting are progressively earning a role as a less invasive alternative in the treatment of carotid occlusive disease. The most common approach for carotid artery stenting involves transfemoral access and use of a filter or balloon device for neuroprotection. This approach has limitations related to both the site of access and the method of neuroprotection. Specifically, an aortoiliac segment with advanced occlusive or aneurysmal disease or an anatomically unfavorable or atheromatous arch and arch branches can significantly limit the safety of the retrograde transfemoral pathway to the carotid bifurcation. Additionally, data provided by the use of transcranial Doppler monitoring and diffusion-weighted magnetic resonance imaging in patients undergoing filter- or balloon-protected carotid artery stenting demonstrate that currently available devices are associated with a considerable incidence of cerebral embolization. To address these limitations, we, along with others, have employed a direct transcervical approach for carotid artery stenting that incorporates the principle of flow reversal for neuroprotection. The technique bypasses all of the anatomic limitations of transfemoral access and simplifies the application of flow reversal, which is one of the safest neuroprotection techniques. The purpose of this review is to describe our method of transcervical carotid artery stenting, review the accumulating outcomes data, and discuss the clinical advantages of and indications for this increasingly popular technique.

Intracranial Hemorrhage After Carotid Angioplasty:A Pooled Analysis

PURPOSE

To use a pooled analysis of the literature to find the incidence of and characteristics common to intracranial hemorrhage (ICH) associated with carotid artery stenting (CAS).

METHODS

A search of the English-language literature (1996-2005) was performed in PubMed to find cases of CAS-associated ICH. Information was derived from the identified case studies in 5 categories and 19 aspects: (1) incidence of CAS-associated ICH; (2) demographic data (sex, age, symptom presentation, and presence of preexisting hypertension); (3) imaging data (side of lesion, degree of maximal stenosis, lesion location, status of the contralateral carotid artery, collateral circulation, and preprocedural imaging features); 4) procedure-related characteristics (antithrombotic medication, use of cerebral protection devices, residual stenosis, symptoms, interval from the procedure to ICH, type of ICH, and blood pressure changes); and (5) clinical outcome.

RESULTS

Fifty-four cases of CAS-associated ICH were reviewed: 51 cases from 36 published articles and our own 3 cases. The incidence of CAS-associated ICH was 0.63% (95% CI 0.38% to 0.97%) in studies consisting of >100 cases, which was significantly lower (p<0.0001) than that of case series consisting of <100 cases (2.69%, 95% CI 1.75% to 3.94%). Distinctive features included symptomatic lesions, severe stenosis (> or =90%), maximal stenosis in the internal carotid artery (ICA) distal to the bifurcation, and preexisting cerebral infarction.

CONCLUSION

The incidence of CAS-associated ICH was significantly lower in series consisting of >100 cases. More caution should be directed toward patients with symptomatic lesions, severe stenosis, maximal ICA stenosis distal to the carotid bifurcation, and preexisting cerebral infarction.

New distal embolic protection device the FiberNet® 3 dimensional filter: First carotid human study

OBJECTIVE

Evaluate the performance and safety of the FiberNet Embolic Protection System during carotid artery intervention.

BACKGROUND

Carotid Angioplasty and Stenting (CAS) can be proposed to treat the majority of carotid stenoses. Brain embolization takes place and routine use of Embolic Protection Devices (EPD) is warranted. Many EPDs have significant limitations, which may be addressed by a new EPD, the FiberNet (Lumen Biomedical, Plymouth, MN).

METHODS

The system consists of a 3-dimensional expandable filter made of fibers, which expand radially, mounted onto a 0.014'' wire and retrieval catheter. FiberNet can capture particles as small as 40 microm without compromising flow.

RESULTS

35 lesions treated in 34 patients. Male 67.6%. Age: 71.4 +/- 8.8 (50-85). Average stenosis 84.5% +/- 7.9 (70-99). 29.4% were symptomatic. Technical success: 34/35 (97%). No stroke or death within 30 days. Neurological events: two permanent amaurosis, one amaurosis fugax. All samples visually contained significant amounts of emboli. The mean surface area of debris caught was 63.8 mm(2) (37.7-107.5). Comparisons were made with other EPDs. The mean surface area of debris caught was 12.2 mm(2) (2.7-34.3). No changes were noted in CT/MRI at 30-day post procedure.

CONCLUSION

The first human use of this new novel EPD in carotid artery stenting is encouraging. The FiberNet was easy to use and confirmed the ability to capture particles less than 100 microm. The feasibility of the FiberNet has been demonstrated. Additional patients will demonstrate the overall safety and efficacy of this new EPD device.

Endovascular Treatment of Peripheral Vascular Disease

An estimated 10 million people in the U.S. have symptomatic peripheral arterial disease (PAD); 20 to 30 million have asymptomatic PAD. The prevalence of intermittent claudication increases with age, affecting >5% of patients over 70. The incidence of claudication doubles or triples in patients with diabetes. As people grow older, symptoms from peripheral vascular disease increasingly limit daily activity. Until recently, vascular surgical procedures were the only alternative to medical therapy in such patients. Today, advances in minimally invasive percutaneous interventions have made endovascular procedures the primary modality for revascularization in most patients. Compared with open surgical procedures, endovascular interventions offer comparable or superior long-term rates of success with very low rates for morbidity and mortality. Furthermore, most of these interventions are performed on an outpatient basis, reducing hospital stays considerably. In this monograph we discuss current endovascular interventions for treating occlusive PAD, aneurysmal arterial disease, and increasingly common venous occlusive diseases.

Renal angioplasty and stenting: long-term results and the potential role of protection devices

Renal angioplasty and stenting have become the first treatments to be proposed to patients presenting with renal artery stenosis. The immediate technical success rate is high, with a low complication rate and good long-term patency. In most reports, renal stenting has been proven to improve blood pressure. However, despite good immediate- and long-term results, postprocedural deterioration of renal function is a concern, and may occur after renal artery angioplasty and stenting in 20 to 40% of patients, which limits the immediate benefits of this technique. Of the causes of this deterioration in renal function, atheroembolism seems to play an important role. Contrary to earlier beliefs that atheroembolization is not an issue during percutaneous catheter interventions, there is now mounting evidence that distal atherosclerotic debris commonly embolizes from lesions in many vascular territories during percutaneous interventions. Atheroembolism seems to be the root cause of many procedural complications wherever atherosclerotic lesions are treated. Distal embolization was first demonstrated in saphenous vein grafts and now, clinical data are proving that similar embolization and distal-organ complications also occur during catheter treatment in certain native coronary lesions, carotid stenting and renal artery stenting, demonstrating the role and efficacy of protection devices to reduce the incidence of end-organ complications. The same protection devices (protection balloon and filters) utilized for coronary or carotid procedures may be used to protect the kidney from atheroembolism. In this review, the authors discuss recently published data concerning the techniques and results of renal angioplasty and stenting procedures performed under protection, and evaluate the benefits of this technique on renal function and its role in the future. Indications for this technique need to be discussed.

Cerebral ischemia associated with PercuSurge balloon occlusion balloon during carotid stenting: Incidence and possible mechanisms

BACKGROUND

Interruption of antegrade cerebral perfusion results in transient neurologic intolerance in some patients undergoing carotid angioplasty and stenting (CAS). This study sought to evaluate factors that contributed to the development of cerebral ischemia during PercuSurge balloon occlusion and techniques used to allow successful completion of the CAS procedure.

METHODS

The PercuSurge occlusion balloon was used in 43 of 165 patients treated with CAS for high-grade stenosis (mean stenosis, 90%). All 43 patients were at increased risk for endarterectomy (7 restenosis, 3 irradiation, 3 contralateral occlusion, and 30 Goldman class II-III); 20% were symptomatic. Symptoms of cerebral hypoperfusion during temporary occlusion of the internal carotid artery occurred in 10 of 43 and included dysarthria (7/10), agitation (6/10), decreased level of consciousness (5/10), and focal hemispheric deficit (3/10). An incomplete circle of Willis or contralateral carotid artery occlusion, or both, was present in 8 of 10 patients. Symptoms resulting from PercuSurge balloon occlusion were managed by balloon deflation with or without evacuation of blood from the internal carotid artery using the Export catheter. All symptoms resolved completely without deficit after deflation of the occlusion balloon.

RESULTS

The development of neurologic symptoms after initial PercuSurge balloon inflation and occluded internal carotid artery flow was associated with a decrease in the mean Glasgow Coma Scale (GCS) from 15 to 10 (range, 9 to 14); the GCS returned to normal after occlusion balloon deflation and remained normal during subsequent reinflation. The mean time to spontaneous recovery of full neurologic function was 8 minutes (range, 4 to 15 minutes). No thrombotic or embolic events were present on cerebral angiography or computed tomography scan. Balloon reinflation was performed after a mean reperfusion interval of 10 minutes after full neurologic recovery (range, 4 to 20 minutes). The mean subsequent procedure duration was 11.9 minutes (range, 6 to 21 minutes). No recurrence of neurologic symptoms occurred when the occlusion balloon was reinflated. All 10 patients underwent successful CAS without occlusion, dissection, cerebrovascular accident, or death.

CONCLUSION

Several factors may contribute to the development of neurologic intolerance during CAS with balloon occlusion. Elucidation of the protective cellular mechanisms that invoke ischemic tolerance after the initial transient ischemic event may enable CAS with embolic protection in patients who cannot tolerate initial interruption of antegrade cerebral perfusion.

Distal Embolus Protection With an Intra-Aortic Filter During Stent-Graft Repair of a Severely Atherosclerotic Thoracic Aortic Aneurysm

PURPOSE

To assess the technical feasibility and efficacy of distal embolus protection with an intra-aortic filter during stent-graft repair in a patient diagnosed with a shaggy aorta.

TECHNIQUE

In a 75-year-old man with a severely atherosclerotic thoracic aortic aneurysm, stent-graft repair was combined with transposition of the arch branches to the ascending aorta under thoracotomy. A filtration-type embolus protection device with a nitinol basket and polyester fabric was introduced through a 12-F sheath and opened in the supraceliac aorta during the stent-graft procedure; it was safely pulled back into the sheath after the stent-grafts were implanted. The stent-graft repair was successful, and abundant atheromatous debris was captured in the filter. Neither procedure-related embolic events nor neurological deficits were observed.

CONCLUSIONS

Use of the intra-aortic filter device to prevent distal embolism during thoracic stent-graft repairs may be feasible and efficacious in severely atherosclerotic patients.

Abrupt Flow Arrest in the Internal Carotid Artery during Carotid Artery Stenting Using the Parodi Anti-Emboli System

We report a rare complication of carotid artery stenting (CAS) in a patient with severe carotid artery stenosis. CAS with a protection of the Parodi Anti-Emboli System was complicated by an abrupt flow arrest in the internal carotid artery before the guidewire passage through the stenotic site.

Protected stent-assisted angioplasty in radiation-induced carotid artery stenosis

OBJECTIVE

The surgical treatment of radiation-induced carotid stenosis is challenging and presents a high rate of complications. This has led several investigators to propose stent-assisted angioplasty as the treatment of choice for this condition. The aim of this study is to evaluate the potential risks of intra-procedural embolic stroke in this setting using cerebral protection devices.

METHODS

We describe our recent experience in the endovascular treatment by means of stent-assisted angioplasty with the aid of a filter cerebral protection device of eight patients presenting with radiation-induced carotid stenosis.

RESULTS

Procedural success, defined as residual stenosis of less than 30% was obtained in all cases. The mean percentage stenosis was reduced from mean 80+/-6.3% (range 70-90%) to 13+/-4% (range 10-20%). Predilation was performed in five cases, post-dilation in all the cases. Mild-to-moderate bradycardia while inflating the balloon was present in three cases and was severe in one case. No patient sustained myocardial infarction, stroke or TIA during the procedure or hospital stay. During a mean clinical follow-up of 16+/-7.3 months (range 5-25) there were no neurological events. On sonographic follow-up, no patient presented in-stent de novo stenosis.

DISCUSSION

Carotid angioplasty with cerebral protection can be performed safely in radiation-induced carotid stenosis with a high technical success rate. With the recent innovations and improvements in angioplasty technique, its indications and results will have to be redefined. Given the complexity and complications of surgical approaches for this condition, and the encouraging results obtained with endovascular techniques, carotid angioplasty emerges as the preferred treatment option.

Fibromuscular dysplasia

The most common clinical manifestations of fibromuscular dysplasia (FMD) are hypertension due to renal artery involvement and transient ischemic attack or stroke due to carotid or vertebral artery involvement. Patients with renal artery FMD and hypertension should undergo primary angioplasty with the goal of curing the hypertension. If the blood pressure fails to normalize following angioplasty, the physician should institute antihypertensive medications according to the recommendations of the Joint National Committee on the Prevention, Detection, and Treatment of High Blood Pressure VII. In patients with cerebrovascular FMD, antiplatelet agents represent the cornerstone of therapy. Percutaneous angioplasty has emerged as the preferred treatment for symptomatic cerebrovascular FMD.

Bilateral carotid angioplasty and stenting

Bilateral carotid stenosis is generally treated by staged stenting procedure and rarely simultaneously due to concerns about hemodynamic impairment from stimulation of the carotid sinus baroreflex (severe bradycardia, hypotension) and the risk of cerebral hyperperfusion syndrome. Most of the accounts of bilateral carotid stenting are of small series. The aim of this study was to evaluate the feasibility and safety of simultaneous bilateral carotid angioplasty and stenting (CAS) in comparison with staged procedure. We retrospectively analyzed the procedural outcome and complications of bilateral CAS done between February 1995 and June 2004 in a consecutive series of 57 high-risk patients. Mean age was 64 +/- 9 years (male, 43; female 14). One hundred fifteen arteries were treated (one patient had bilateral internal carotid artery stenosis associated to an ostial common carotid artery stenosis). Thirty-nine patients were symptomatic (70%). Thirty-six patients had severe coronary artery disease. Seventeen patients underwent a simultaneous bilateral CAS (group 1), 40 in a staged manner (group 2). Among these 40 patients 10 were treated with a time interval of 24 hr, while the 30 other ones were treated with a time interval of 2 days to 2 months. A neuroprotection device was used in the last 42 patients. There was technical success in all patients and transient bradycardia and/or hypotension in 25 patients (44%). There was no prolonged bradycardia or hypotension. At 30 days, we observed in group 1 (simultaneous bilateral CAS) no transient ischemic attack (TIA), no minor stroke, one (5.8%) major stroke (hyperperfusion syndrome with brain hemorrhage leading to death in a patient under IIb/IIIa inhibitors), one myocardial infarction leading to death, and two (11.7%) death/stroke/myocardial infarction; in group 2 (staged procedure), two (5%) TIAs, no minor stroke, no major stroke, and one (2.5%) hyperperfusion syndrome with rapid recovery. Among the 10 patients treated with a time interval of 24 hr, we observed one TIA. Among carefully selected patients, bilateral CAS is feasible simultaneously or the day after, with a safety and complication rate comparable to that of large published series of CAS or endarterectomies in high-risk patients. Nevertheless, careful monitoring of the patient, blood pressure, and heart rate is mandatory to avoid complications related to hyperperfusion syndrome. Routine use of neuroprotection device and meticulous technique should improve the outcomes of bilateral CAS.

Continuity in the Treatment of Carotid Artery Disease: Results of a Carotid Stenting Program Initiated by Vascular Surgeons

The treatment of carotid artery stenosis currently constitutes a major component of vascular surgical practice. Carotid angioplasty and stenting (CAS), however, is mainly performed by nonvascular surgeon interventionalists with cerebral protection devices available only through investigational protocols. This study reports the initial results of a CAS program initiated and performed by vascular surgeons using commercially available cerebral protection devices. Fifty-seven patients were enrolled in the study over a 14-month period. All patients were at high risk for conventional endarterectomy (7 resentosis, 4 irradiation, and 46 medically high-risk ASA III). Mean age was 75.7 years (range, 45-93 years). High-grade stenosis of the carotid artery was present in all cases (mean stenosis, 85%; range, 80-99%). Twenty-four percent of patients were symptomatic. Cerebral protection was performed with an occlusion balloon-wire in 32 cases and with a filter-wire device in 24; no cerebral protection was used in 1 patient with restenosis after endarterectomy. Initially in the study, atropine was administered selectively for the development of bradycardia. Currently atropine is administered routinely prior to the initial balloon angioplasty of the carotid bulb. Clopidogrel (75 mg/day) was administered for 5 days prior to CAS and for 30 days after CAS. All 57 patients underwent successful dilatation of their carotid stenoses without occlusion or dissection. Ten of 32 patients in whom balloon occlusion was used for cerebral protection exhibited transient evidence of cerebral ischemia during protection balloon occlusion. These symptoms resolved completely without permanent neurological deficit in all cases. Development of bradycardia with a heart rate <50 bpm was significantly reduced by routine administration of atropine prior to the initial dilatation within the carotid bulb (p = 0.01). Mean hospital length of stay was 1.33 days (range, 1-5 days). There were two periprocedure myocardial infarctions, two postprocedure transient ischemic attacks, and one reversible ischemic neurologic deficit. There was no 30-day mortality. There have been no instances of hemodynamically significant restenosis during a mean follow-up period of 5.4 months. From these results we have concluded that CAS can be performed effectively and safely using commercially available cerebral protection devices. A program initiated and performed exclusively by vascular surgeons is effective and should be the standard model used in the endovascular treatment of carotid artery stenosis.

Carotid artery surgery vs. stent: A cardiovascular perspective

Stroke is a major health catastrophe that is responsible for the third most common cause of death and the leading cause of disability. Carotid artery stenosis is an important cause of brain infarctions and the risk of stroke is directly related to the severity of carotid artery stenosis and to the presence of symptoms. Familiarity with different methods of measuring degrees of carotid artery stenosis is a key in understanding the role of revascularization of this disorder. Carotid endarterectomy (CEA), surgical removal of the carotid atherosclerotic plaque, is intended to prevent stroke in patients with carotid artery stenosis and currently the most commonly performed vascular procedure in the United States. Several randomized clinical trials had demonstrated the benefits of CEA in selected groups of patients with symptomatic and asymptomatic carotid artery stenosis. However, CEA can cause stroke, the very thing it intended to prevent, and is associated with significant perioperative complications such as those related to general anesthesia, cardiac or nerve injury. Moreover, several anatomical and medical conditions may limit candidates for CEA. Carotid artery stenting (CS) is an evolving and less invasive technique for carotid artery revascularization. Recent studies demonstrated that CS with embolic protection devices has become an alternative to CEA for high-surgical-risk patients and the procedure of choice for stenoses inaccessible by surgery. The role of CS in low risk patients awaits the completion of several ongoing studies.

Transcervical carotid stenting with internal carotid artery flow reversal: Feasibility and preliminary results

OBJECTIVE

Transfemoral carotid artery stenting (CAS), with or without distal protection, is associated with risk for cerebral and peripheral embolism and access site complications. To establish cerebral protection before crossing the carotid lesion and to avert transfemoral access complications, the present study was undertaken to evaluate a transcervical approach for CAS with carotid flow reversal for cerebral protection.

METHODS

Fifty patients underwent CAS through a transcervical approach. All patients with symptoms had greater than 60% internal carotid artery (ICA) stenosis, and all patients without symptoms had greater than 80% ICA stenosis. Twenty-one patients (42%) had symptomatic disease or ipsilateral stroke, and 8 patients (16%) had contralateral stroke. Four patients (8%) had recurrent stenosis, 7 patients (14%) had contralateral ICA occlusion, and 1 patient (2%) had undergone previous neck radiation. Twenty-seven procedures (54%) were performed with local anesthesia, and 23 (46%) with general anesthesia. Using a cervical cutdown, flow was reversed in the ICA by occluding the common carotid artery and establishing a carotid-jugular vein fistula. Pre-dilation was selective, and 8-mm to 10-mm self-expanding stents were deployed and post-dilated with 5-mm to 6-mm balloons in all cases.

RESULTS

The procedure was technically successful in all patients, without significant residual stenoses. No strokes or deaths occurred. There was 1 wound complication (2%). All patients were discharged within 2 days of surgery. Mean flow reversal time was 21.4 minutes (range, 9-50 minutes). Carotid flow reversal was not tolerated in 2 patients (4%). Early in the experience, carotid flow reversal was not possible in 1 patient, and there were 1 major and 3 minor common carotid artery dissections, which resolved after stent placement. One intraoperative transient ischemic attack (2%) occurred in 1 patient in whom carotid flow was not reversed, and 1 patient with a contralateral ICA occlusion had a contralateral transient ischemic attack. At 1 to 12 months of follow-up, all patients remained asymptomatic, and all but 1 stent remained patent.

CONCLUSION

Transcervical CAS with carotid flow reversal is feasible and safe. It can be done with the patient under local anesthesia, averts the complications of the transfemoral approach, and eliminates the increased complexity and cost of cerebral protection devices. Transcervical CAS is feasible when the transfemoral route is impossible or contraindicated, and may be the procedure of choice in a subset of patients in whom carotid stenting is indicated.

Management of carotid injuries in a hostile neck using endovascular grafts

Pseudoaneurysms and iatrogenic injuries of the extracranial carotid artery are not common but represent unique operative challenges with associated high morbidity and mortality. We report two cases in which a Wallgraft was used via percutaneous femoral access to treat such injuries. In the first, a 6-cm carotid pseudoaneurysm was successfully excluded by coil embolization of the external carotid artery and stent grafting across the carotid bifurcation. In the second case, an endovascular graft was used to treat an intraoperative common carotid injury in a re-operated, radiated neck. These cases demonstrate the utility of endovascular graft treatment of emergent carotid injuries.

A new approach to carotid angioplasty and stenting with transcervical occlusion and protective shunting: Why it may be a better carotid artery intervention

OBJECTIVE

The purpose of this study was to evaluate the effectiveness and demonstrate the advantages of a new technique for carotid angioplasty and stenting (CAS) with proximal cerebral protection through a direct transcervical approach, as compared with a percutaneous transfemoral approach.

METHODS

CAS procedures were carried out in 25 consecutive patients, 4 with the femoral approach and 21 through a 2-cm incision at the base of the neck, with the patient under local anesthesia. For transcervical occlusion and protective shunting (TOPS), a short 9F sheath was inserted directly into the common carotid artery and connected to a 6F sheath placed percutaneously in the ipsilateral internal jugular vein. After clamping the common carotid artery proximal to the 9F sheath, internal carotid artery blood flow reversal was confirmed or an occluding external carotid balloon was placed. A filter interposed between the arterial and venous sheaths collected embolic debris from transcarotid manipulations. The arterial puncture was directly repaired with suture. Neurologic status was assessed with the National Institutes of Health stroke scale by an independent neurology consultant before and after the procedure.

RESULTS

One of the four percutaneous femoral approaches that failed because of tortuous anatomy was successfully treated with TOPS. Angiographic confirmation demonstrating resolution of asymptomatic (>80%; n = 12) stenosis or symptomatic (>60%; n = 12) stenosis was achieved in all patients with stents. A 0% technical failure rate and 0% combined 30-day stroke or mortality rate were achieved in all CAS attempted with TOPS. There were no hematomas in the cervical group, despite pretreatment with clopidogrel bisulfate and heparin, and one hematoma in the femoral group after failure of a Perclose arterial closure device. In one of the patients in the femoral group bilateral cholesterol emboli to the toes developed.

CONCLUSION

TOPS solves problems of access, embolization into the cerebral and peripheral circulation, and specialized cerebral protection devices, and enables secure closure of the access vessel in patients given anticoagulation therapy. TOPS may provide a safer, more effective, economical means for performing CAS.

Comparison of 4 Cerebral Protection Filters for Carotid Angioplasty:An In Vitro Experiment Focusing on Carotid Anatomy

PURPOSE

To assess the influence of internal carotid artery (ICA) tortuosity on the effectiveness of 4 cerebral protection filters in an in vitro bench-top model.

METHODS

To simulate the anatomical arterial variants, 3 open flow models were constructed: one with normal carotid anatomy, 1 representing a mildly tortuous ICA, and a third imitating a severely tortuous ICA. Polyvinyl alcohol particles (150-1000 microm) served as the embolic material; the emboli were divided into 3 groups according to size: small (150-250 microm), medium (355-500 microm), and large (710-1000 microm). Five milligrams of each size group were injected separately into the ICA proximal to each of 4 protection filters: AngioGuard, FilterWire EX, TRAP, and NeuroShield. Emboli that were not caught by the protection system or were washed into the external carotid artery (ECA) ran into an effluent filter and were weighed and classified according to size.

RESULTS

In 240 test runs, the FilterWire EX presented the lowest weight of emboli in the ICA effluent under all anatomical conditions: normal anatomy 0.39 mg (2.58%), mild tortuosity 0.45 mg (2.99%), and severe tortuosity 0.50 mg (3.33%) (p>0.05). The Angioguard system showed the worst results: normal 1.21 mg (98.03%), mild tortuosity 2.54 mg (16.84%), and severe tortuosity 3.14 mg (20.91%) (p<0.001) compared to the FilterWire EX and the NeuroShield systems. The only protection device displaying no significant differences in all of the 3 emboli sizes was the FilterWire EX (p>0.05). Relevant differences in effectiveness in mildly and severely tortuous ICAs were apparent among the other devices. For all emboli sizes, the differences of the AngioGuard and TRAP systems were highly significant (p<0.001). There was no significant difference between the FilterWire EX and the NeuroShield.

CONCLUSIONS

The only protection device showing no significant decrease in efficacy in the tortuous ICA models was the FilterWire EX. In both tested anatomical variants, the protection systems ranked in the same order of effectiveness. None of the tested devices prevented embolization completely.

Treatment Outcome of Carotid Stenting and CEA in the Same Period

SUMMARY

Angioplasty with stent deployment is a promising option for the treatment of carotid stenosis. However, the definite treatment indication is still unknown through lack of scientific evidences in the randomized controlled trial, which is now on going. We compared the short-term outcome, such as periprocedural complication rate, cerebral blood flow, subsequent ischemic events and restenosis, between carotid stenting (CS) and carotid endarterectomy (CEA) in the same period to investigate the justice of our present indication for CS. Fifty-five patients with carotid stenosis greater than 70% were treated by CS or CEA in a constant indication. Twenty-five times of CEA were indicated in patients who satisfied the inclusion criteria of NASCET without the exclusion criteria, 30 times of CS in patients with the exclusion criteria. No major procedure-related complication was found in either group. One patient (3.3%) in CS group suffered a minor ischemic stroke during the procedure, just after postdilatation. One patient underwent myocardial infarction in CEA group, and one patient congestive heart failure in CS group within one week after the procedure. During a mean follow-up period of 19 months, no further stroke occurred in either group. There was no lesion-related mortality, but one patient in each group was dead of heart disease. As for restenosis, one patient in each group showed recurrent stenosis on angiogram 12 and 24 months after the treatment. Restenosis rate calculated by the personyear method in CEA and CS group was almost same, 2.3% per year. Stenting seemed to be so safe and effective for cases refractory to CEA that the present indication for CS is thought to be reasonable, though it is necessary to draw a decisive conclusion in randomized trials.

Carotid stenting versus carotid surgery: a prospective cohort study

PURPOSE

To compare the results of carotid stenting and carotid surgery in a consecutive group of 455 patients (482 lesions).

METHODS

Between January 1995 and July 2002, 107 patients (114 lesions) were treated with carotid stenting and 348 patients (368 lesions) with carotid surgery. A cerebral protection device was routinely used in the last 46 stent cases. All patients were followed with duplex examination at 1 and 6 months postoperatively and yearly thereafter.

RESULTS

The stent and surgery groups were similar in terms of mean age (70.5 and 71.1 years, respectively), sex distribution (men 72% versus 75%), and symptoms (transient ischemic attack [TIA] or minor stroke 32.7% versus 42.2%). Median follow-up was 15 months in stent patients and 14 months in the surgical group. At 1 month postoperatively, there were 7 minor strokes (5 temporary lasting <21 days and 2 persistent) and 1 major stroke in the stent group versus 1 persistent minor stroke in the surgical patients. The overall neurological event rate (including TIA) was 10.5% versus 1.9% (p=0.0002) in the surgical patients; cardiac morbidity was 3.5% versus 1.6% (p=NS), and the death rate was 0% versus 0.8% (p=NS). The combined permanent stroke/death rate was 2.6% in stent patients and 1.1% in surgery patients (p=NS). During follow-up, the cumulative all stroke rate was 8.8% versus 1.9% (p=0.001), but the 3-year cumulative survival rate free from ipsilateral major neurological events was 95.2% in stent patients and 96.9% in the surgery cohort (p=NS). There was a 7.5% rate of restenosis in stented arteries versus 1.4% in surgery patients (p=0.001).

CONCLUSIONS

This series showed encouraging and comparable major stroke and deaths rate of carotid stenting and carotid surgery. However, there was more restenosis in the stented group on midterm follow-up.

Carotid angioplasty under cerebral protection with the percusurge guardwire system

The purpose of this study was to examine the possible beneficial effect of the PercuSurge GuardWire cerebral protection device based on balloon occlusion of the distal internal carotid artery and debris aspiration for patients undergoing carotid artery stenting (CAS). A total of 268 CAS procedures were attempted under cerebral protection using the PercuSurge GuardWire system in 242 patients (194 men; mean age, 71.2 +/- 9.4 years; range, 40-91). The lesions were mainly atherosclerotic; 64% were symptomatic. Technical success was 99.3%. All lesions were stented except three postangioplasty restenoses. Prophylactic occlusion during balloon dilatation and stenting was well tolerated in 255 patients (95.9%). Microscopic analysis of the aspirated blood showed different types of particles numbering between 7 and 145 per procedure, with a mean diameter of 250 microm (mean, 56-2,652 microm). The 30-day stroke and death rate was 2.3%, with four periprocedural complications at < 48 hr (one retinal embolism and three transient ischemic attacks), one intracerebral hemorrhage at 3 days, and one death of cardiac failure at 3 weeks. This technique appears safe and efficient with a low rate of periprocedural embolic events. Protection devices seem indispensable to perform CAS and expand the applicability of the procedure. Randomized studies (surgery vs. CAS with and without cerebral protection) are awaited.