Treatment Of Carotid Artery Stenosis Research Articles

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 stenosis: Routine predilatation or direct stenting?

Stenting is a potential alternative treatment for carotid artery stenosis. Direct stenting may, theoretically, reduce the risk of embolism by minimizing plaque manipulation before tissue scaffolding is achieved. The results of direct carotid stenting are reported and compared with those of stenting with predilatation. One hundred and seventy‐four carotid artery stenoses were treated from July 1998 to February 2002, with 84 lesions directly stented (Group 1) and the other 90 lesions stented after predilatation (Group 2). The criteria for direct stenting were minimal luminal diameter (MLD) &gt; 1 mm and no visible thrombus angiographically. Technical success rates of the two groups were both 100%, without any cross‐over. Reference vessel diameter and lesion length did not differ between the two groups. In Group 1, diameter stenosis was lower (79 ± 8 vs 92 ± 7%, P &lt; 0.001) and MLD was larger (1.1 ± 0.5 vs 0.4 ± 0.4 mm, P &lt; 0.001) than that in Group 2, but the final MLD (4.7 ± 0.9 vs 4.7 ± 0.9 mm, P = 0.94) of the two groups were not statistically different. The periprocedural ipsilateral stroke or death rates were also similar in the two groups (2/84 vs 4/90, P = 0.68). It was concluded that if the MLD of carotid stenosis is larger than 1 mm and no thrombus is present, direct stenting could be carried out safely with results comparable to that of stenting after predilatation.

Carotid Artery Stenting:The Need for Randomised Trials

Endovascular treatment for carotid artery stenosis avoids some of the complications of carotid endarterectomy, but has not been widely accepted. Concerns about the risks and benefits of endovascular treatment led to the Carotid and Vertebral Artery Transluminal Angioplasty Study (CAVATAS). There was no difference in major outcome events between endovascular treatment and carotid endarterectomy, but the rate of procedural stroke or death was higher than desirable. There was no difference either in the rate of stroke during follow-up, but the confidence intervals were very wide and severe ipsilateral carotid stenosis was more frequent 1 year after endovascular treatment than after carotid surgery. Two other randomised trials of carotid stenting were stopped early after poor outcomes in stented patients. These early trials used techniques which have now been superseded, but the results emphasise the need to improve the safety of endovascular treatment. Recent advances designed to improve safety include new designs of stents and delivery systems, and devices designed to protect the brain from embolisation during stenting. However, there is little convincing evidence that these new devices reduce the rate of stroke. Moreover, a systematic review of the existing randomised trial data concluded that there the current evidence does not support a shift away from recommending carotid endarterectomy as the standard treatment for carotid stenosis. There is therefore a clear need for further randomised trials of carotid stenting. Three of the ongoing trials, EVA-3S, SPACE and ICSS (CAVATAS-2), have prospectively agreed to combine individual patient data after completion of follow-up. This meta-analysis will provide results similar to a mega-trial and should also allow informative subgroup analyses. The co-operation between the trials in agreeing to perform this meta-analysis is a major advance in trial design. The result should determine whether carotid stenting truly rivals carotid endarterectomy as the treatment of choice for carotid stenosis.

Effective treatment of carotid artery stenosis on blood pressure: a comparison of hemodynamic disturbances after carotid endarterectomy in endovascular treatment

Conclusion: Carotid endarterectomy and endovascular treatment of carotid artery stenosis both affect blood pressure stability during the first 24 hours after the procedure. Compared with preoperative baseline levels, systolic blood pressure at 6 months is lower in patients who undergo surgery, and is unchanged in patients who undergo endovascular treatment. Summary: Periprocedure and long-term blood pressure effects of carotid endarterectomy and endovascular treatment of carotid artery stenosis were studied in patients randomized at a single center in the Carotid and Vertebral Artery Transluminal Angioplasty Study (CAVATAS). Patients were randomized to endovascular treatment of carotid stenosis (n = 55) or carotid endarterectomy (n = 49). Ambulatory 24-hour blood pressure monitoring was recorded before carotid intervention and at 24 hours, 1 month and 6 months after intervention. Hypotension and hypertension were defined as a decrease or increase, respectively, in systolic blood pressure of 30 mm Hg or greater from baseline blood pressure recordings. After the procedure, in the first 24 hours hypotension occurred in 76% of the endovascular group and 75% of the carotid endarterectomy group, and hypertension occurred in 13% and 11%, respectively. At 1 hour systolic blood pressure decreased by a mean of 24 mm Hg in the surgical group and 16 mm Hg in the endovascular group; however, the decrease was sustained only in the endovascular group (P < .0001). At 6 months systolic pressure was at baseline in the endovascular group, and was 5 mm Hg lower in the surgical group. Thirty-day stroke and mortality rate was 10.2% in the surgical group, and 5.5% in the endovascular group. Perioperative neurologic complication was not related to perioperative hemodynamic disturbance. Comment: The study suggests a difference in blood pressure response after surgical versus endovascular therapy for carotid artery stenosis. In surgical patients, however, a specific protocol was used to reverse hypotension, whereas no specific protocol was used in the stent group. The 6-month data are difficult to interpret, because there is no follow-up information on number and dosage of antihypertensive medications in either group. This study should be regarded as hypothesis-seeking, and does not definitively establish a difference in blood pressure response after carotid endarterectomy versus carotid stenting.

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

To evaluate the performance of the FilterWire EX for the capture and removal of debris and prevention of embolic events during endovascular carotid interventions. In the period from October 2001 to May 2002, 100 patients (60 men; mean age 72 years, range 48-90), 69 symptomatic with >or=50% internal carotid artery (ICA) stenosis and 31 asymptomatic with >or=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. 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). 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.

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 >or=50% internal carotid artery (ICA) stenosis and 31 asymptomatic with >or=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). CONCLUSION 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.

Editorial Comment—Carotid Artery Stenting With or Without Protection Devices? Strong Opinions, Poor Evidence!

In recent years, endovascular treatment of carotid artery stenosis has profited from substantial technical improvements, but the dominant point of discussion circles around the so-called cerebral protection devices. In this issue of Stroke , Cremonesi et al1 report their impressive single-center experience with protected carotid artery stenting (CAS) in 442 patients. The overall complication rate was 3.4%, and the 30-day ipsilateral stroke/death rate was 1.1%. The authors conclude that protection devices are feasible and effective in preventing distal embolization. In a recent Stroke issue, Kastrup et al,2 who systematically reviewed single-center CAS studies, concluded that protection devices appear to reduce thromboembolic complications during CAS. The appearance of debris during CAS and carotid endarterectomy (CEA) is a common event.3,4 At first glance, it seems reasonable to apply protection systems to catch particles by means of occlusive balloon systems or filtration baskets in the internal carotid artery. The beneficial use of such devices seems to be supported by a growing number of publications, mostly from the field of cardiology, reporting declining neurological complication rates. Despite the lack of further controlled studies, the use of protection devices has even become obligatory in the CREST (United States)5 and EVA3S (France) trials testing for equivalence of CAS and CEA. Paradoxically, some neuroradiologists continue to successfully perform CAS without protection devices …

The relationship between carotid atherosclerotic plaque morphology and the embolic risk during endovascular therapy

Eur J Vasc Endovasc Surg 26, 17-21 (2003)

Current concepts of mechanical cerebral protection during precutaneous carotid intervention.

Major advances in the endovascular treatment of carotid artery stenosis are underway, with an emphasis on improving the safety profile of the technique. This review highlights key areas in the concepts and design of available mechanical neuroprotection devices utilized during carotid stenting to minimize procedural cerebral embolization. The advantages and disadvantages of each system are explored and the available clinical experience is given. The size threshold of particulate material likely to be clinically relevant is examined and compared with pathological analysis of particles trapped by protection systems reported in the world literature. It is shown that the adverse neurological event rate in those protected is lower than that in historical studies of unprotected carotid stenting. Furthermore, the size range and numbers of particles trapped by protections systems are sufficient to cause potential neurological injury if allowed passage to the brain. Further improvements in outcomes may require further refinement of protection technology.

Endovascular Therapies for Vascular Disease

Endovascular techniques including angioplasty, stenting, and endoluminal stent grafts represent important therapeutic options for the treatment of vascular disease. Technologic advances have allowed for the treatment of aneurysmal disease as well as extra-cranial carotid disease that previously required surgical methods. The success of various endovascular therapies varies based on anatomic location and extent of disease. The clinical results in different arterial segments are increasingly recognized in the published literature. The aortoiliac arterial bed appears to respond most favorably, with less favorable results observed in the infra-inguinal and infrapopliteal locations. There is increasing evidence that stent-supported carotid angioplasty using cerebral protection will play an important future role in the treatment of carotid artery stenosis. Less invasive techniques to treat abdominal aortic aneurysms with endoluminal stent grafts have dramatically changed the available therapeutic options. Improved devices and delivery systems will likely increase the number of patients who can be successfully treated in this manner. The evolution of endovascular therapies will continue to change the way we treat vascular disease.

Carotid stenosis: medical and surgical aspects

Medical treatment for carotid disease is similar to the treatment of atherosclerosis, with some recent data suggesting that there is a benefit to an aspirin-dipyridamole combination. CEA has revolutionized the treatment of symptomatic and asymptomatic carotid stenosis. This approach remains the gold standard for the surgical treatment of carotid artery stenosis, against which emerging modalities such as percutaneous carotid stenting should be compared. Higher-risk, asymptomatic patients can safely undergo CEA in high-volume centers for stenosis greater than 80% as defined by ultrasound.

Carotid Angioplasty and Stent Placement: A Prospective Analysis of Perioperative Complications and Impact of Intravenously Administered Abciximab

To determine the frequency of perioperative complications since the introduction of abciximab, we prospectively evaluated our experience in a consecutive series of patients undergoing carotid angioplasty and stent placement (CAS). CAS has been introduced recently for treatment of carotid artery stenosis. A major limitation to this modality is the risk of perioperative thromboembolic and ischemic events. To reduce the risk of ischemic complications, abciximab, a platelet glycoprotein IIb/IIIa receptor inhibitor, has been introduced as adjunctive treatment for high-risk patients. Each patient was evaluated by a neurologist before, immediately after, and 24 hours after CAS for identification and classification of new neurological deficits. Bleeding events or other complications during hospitalization were recorded. Bleeding complications were classified as major (hemoglobin decrease,g5 g/dl), minor (hemoglobin decrease, 3-5 g/dl), or insignificant. Abciximab was administered intravenously as a single bolus (0.25 mg/kg) and then via infusion (10 microg/min) for 12 hours as an adjunct to CAS in patients considered to be at high risk for thromboembolic events owing to recent ischemic symptoms and/or complex lesion morphology. Intravenously administered abciximab was used in 37 patients (mean age, 70 yr; 21 patients were men) as an adjunct to high-risk CAS. Thirty-three other patients underwent CAS performed with standard intraprocedural heparinization (mean age, 69 yr; 17 patients were men). Minor ischemic strokes were observed in 1 of 37 abciximab-treated patients and in 4 of 33 heparin-treated patients. No major ischemic strokes were observed in either group. Transient neurological deficits were observed in nine patients in the abciximab-treated group and in one patient in the heparin-treated group. Transient neurological deficits in abciximab-treated patients were mainly related to hemodynamic factors (associated with balloon inflation in two patients and with hypotension in another two patients) or occurred after completion of infusion (in three patients). Minor bleeding complications were observed in three patients who received abciximab and in four patients who received standard heparinization. Major bleeding complications were observed in four patients from each group. Two patients who received abciximab developed intracerebral hemorrhages; one hemorrhage was fatal. The frequency of ischemic stroke in high-risk patients (3%) with the use of intravenously administered abciximab was lower, but not significantly so, than rates observed in lower-risk patients (12%), although the benefit was lost because of the high rate of intracranial hemorrhages (5%). Further efforts are required to determine appropriate selection criteria for use of intravenously administered abciximab and the effect of other strategies that involve distal protection devices.

Endoscopic approach for carotid artery surgery.

Although recent advances in the treatment of carotid artery stenosis have included endovascular angioplasty and stent placement, carotid endarterectomy is still the approach of choice for carotid disease and is one of the most commonly performed operations today. Minimally invasive surgeries involving the neck have recently been performed for thyroid and parathyroid diseases. The purpose of this study was to evaluate the feasibility of an endoscopic approach for carotid artery surgery in a large animal model. Eight 25- to 30-kg pigs were used. Animals underwent endoscopic carotid dissection with carbon dioxide insufflation at 10 mmHg. A 1.5- to 2-cm arteriotomy was made in the common carotid artery. Four animals underwent direct arteriotomy closure, and four animals underwent synthetic patch graft placement using intracorporeal suturing techniques. Open examination of the operative site and carotid angiograms were performed at the end of the procedure. Operative time was recorded in the last four cases. All animals tolerated the procedure well and carotid artery repair was successfully performed in all cases using a four-trocar technique. The entire extent of the cervical common and internal carotid arteries was exposed up to the cranial base. Cranial nerves and cervical structures were clearly visualized and preserved. No bleeding occurred at the end of the procedure. Carotid angiograms confirmed patent, nonstenotic vessels in all cases. Endoscopic approach for carotid surgery is technically feasible in the porcine model. This approach may represent a valuable option for surgery of the carotid artery since it offers the advantages of minimally invasive techniques while maintaining the benefits of surgical arterial repair.

Carotid Angioplasty with Cerebral Protection and Stenting: Report of 164 Patients (194 Carotid Percutaneous Transluminal Angioplasties)

Background: The introduction of cerebral protection devices with systematic stent placement has changed the nature of carotid artery stenosis treatment, reducing the immediate periprocedural complications and delayed restenosis. Methods: We treated 164 patients with 194 carotid artery stenosis procedures; 92% of them were symptomatic patients. Results: The morbidity rate of our series was 1.03% and the mortality was 1.9%. Conclusions: In the future, carotid stenosis treatment should perhaps be performed as a preventative measure and not used as a cure for full-blown symptoms. This could be effective in reducing the morbidity and mortality rates of this pathology.

813 Outcomes after Treatment of Carotid Artery Stenosis: Patient-reported Health Status Preoperatively and at 6-month Follow-up

813 Outcomes after Treatment of Carotid Artery Stenosis: Patient-reported Health Status Preoperatively and at 6-month Follow-up

813 Outcomes after Treatment of Carotid Artery Stenosis: Patient-reported Health Status Preoperatively and at 6-month Follow-up

813 Outcomes after Treatment of Carotid Artery Stenosis: Patient-reported Health Status Preoperatively and at 6-month Follow-up

Results of a Multicenter Prospective Randomized Trial of Carotid Artery Stenting vs. Carotid Endarterectomy

53 Background: Carotid artery stenosis (CAS) is a common etiology for ischemic stroke. While carotid endarterectomy (CEA) is a safe and effective treatment for CAS, endovascular therapy using carotid stenting may be a reasonable alternative. This multicenter study was designed to determine if carotid stenting was equivalent to CEA in patients with symptomatic CAS. Methods: Patients with symptomatic CAS of 60–99% by cerebral angiogram were prospectively randomized to CEA or carotid stenting. All enrolled patients were reviewed by a multidisciplinary team that included neurologists, surgeons, and interventionalists. Patients in the stent group were treated with the WALLSTENT endoprosthesis and received aspirin 325 mg bid and ticlopidine 250 mg bid for 4 weeks. Neurologic assessments were performed 24 hrs post-procedure, then at 1, 6 and 12 months. The primary end-point was ipsilateral stroke, procedure-related death, or vascular death within 1 year. P-values are from 2-sided Fisher’s Exact Test. Results: A total of 219 patients were enrolled; 107 in the stent group (mean age 66.5, 66% male) and 112 in the CEA group (mean age 70, 62% male). The mean baseline degree of stenosis was 76% in the stent group vs 75% in the CEA group. 65% of stent patients had a TIA vs 68% in the CEA group. Median follow-up days for stent and CEA patients were 354 and 341, respectively. The primary end-point rate at approximately one year was 12.1% in the stent group vs. 3.6% for CEA (p = 0.022). The rate of any major stroke was 3.7% for stent vs. 0.9% for CEA (p = 0.204). A post-stent angiogram showed that 97% of patients had less than 30% stenosis. The 30 day peri-procedure complication rate (any stroke or death) was 12.1% for stents and 4.5% for CEA (p = 0.049). The 2 day peri-procedure complication rate was 7.5% for stents and 1.8% for CEA (p=0.055). Other common peri-procedure complications of stenting were severe bradycardia (7%) and groin hematoma (4%). Conclusions: This study did not find that carotid stenting was equivalent to CEA in patients with symptomatic CAS. Based on these data and a futility analysis, the study was terminated before the planned maximum of 700 patients were enrolled.

Current status of carotid angioplasty and stenting in the treatment of carotid artery stenosis

Current status of carotid angioplasty and stenting in the treatment of carotid artery stenosis

Surgical Management of Atherosclerotic Carotid Artery Stenosis after Cervical Radiation Therapy

Carotid surgery following external cervical irradiation has not been a treatment of choice. The purpose of this retrospective study was to describe the immediate and long-term outcome in a series of 17 consecutive patients who underwent operative treatment for carotid artery stenosis after radiation therapy. From 1989 to 1997, surgical treatment of carotid artery disease was carried out in a total of 723 patients. Seventeen of these patients, 14 men and 3 women, had undergone previous external cervical irradiation; their mean age was 61.7 years. The indication for radiation therapy was ear-nose-throat cancer in 14 patients and lymphoma in 3 patients. In 10 patients, irradiation was associated with cervical surgery. The mean delay between radiation therapy and carotid artery repair was 10 years. All 17 patients were considered to be in remission at the time of carotid repair. The indication for carotid surgery was asymptomatic stenosis in 6 cases (33%) and symptomatic stenosis in 12 (67%). The procedure consisted of endarterectomy in 12 cases (67%) and venous bypass in 6 (33%). The outcome for these patients was favorable, indicating that carotid artery repair following cervical radiation therapy is safe. Results are comparable to those of procedures performed in patients with no history of cervical irradiation.

Carotid Endarterectomy without Pre-operative Angiography

Carotid endarterectomy is being performed with increasing frequency without the benefit of preoperative angiography, based purely on duplex scanning. The available data attest to its safety, with the caveats that the duplex scan is unimpeachable, and that the symptoms and duplex scan findings are consistent.Given the well documented risk of stoke as a consequence of cerebral angiography being at least 1%, the elimination of this risk by the omission of contrast angiography would reduce the neurological morbidity and mortality rate of the diagnosis and treatment of carotid bifurcation disease by approximately 50%. The available data make a compelling case for carotid endarterectomy based on duplex scanning, without preoperative angiography, as the preferred approach to treatment of carotid artery stenosis.