Carotid artery stenting in the first 100 consecutive patients: results and follow up

Stellate ganglion ischemia on the prevention of pulmonary vasospasm during bilateral carotid artery ligation: The first experimental study

Fatal pulmonary edema and hemorrhage are significant complications of endovascular treatment in steno-occlusive carotid artery disease; a rational mechanism has not been adequately examined in the literature so far. We investigated if cervical sympathetic ganglia ischemia prevents pulmonary vasospasm on the prognosis of bilateral common carotid artery ligation (BCCAL). Twenty-three adult New Zealand rabbits (4.2 ± 0.3 kg) were randomly divided into three groups: the control group (G1, n = 5), the sham group (G2, n = 6), and the BCCAL group (G3, n = 12). Common carotid arteries were dissected bilaterally in G2/G3, and permanent BCCAL was applied to only in G3. All animals were followed for 3 weeks and decapitated under general anesthesia. Histopathological changes in stellate ganglia and severity of pulmonary vasospasm-related lung edema and hemorrhage were investigated. Results were analyzed by the Kruskal-Wallis test. Two animals of G3 dead within three weeks and the remainder were sacrificed three weeks later. Subpleural petechial foci and an endotracheal bloody fluid collection were grossly observed in the lungs. Histopathologically, pulmonary artery vasospasm, perivascular and subintimal edema, interalveolar hemorrhage, and alveolar wall destructions were observed with less ischemic-degenerated neuron density-determined stellate ganglia animals. Neurodegeneration of stellate ganglia may have a beneficial effect on the prevention of lung injury during steno-occlusive carotid artery disease.

Carotid Artery Stenting: Current Status and Future Directions

Carotid endarterectomy has been the mainstay of therapy for carotid occlusive disease in stroke prevention. Recent advances in endovascular technology has made carotid angioplasty and stenting a therapeutic modality in the treatment of carotid occlusive disease. The enthusiasm for this minimally invasive carotid intervention is hampered by the possibility of stentrelated cerebral embolization, which can result in neurologic complications. Although current available data indicate that the results regarding success and complication rates are similar between carotid stenting and endarterectomy, numerous prospective clinical trials are currently underway to evaluate the efficacy of carotid artery stenting using various forms of cerebral protection devices. This article reviews the current status of carotid stenting, including recent clinical studies and ongoing prospective trials. Strategies relating to cerebral embolization protection are also discussed.

Determinants of In-Stent Restenosis after Carotid Angioplasty: A Case-Control Study

Purpose:

To report a retrospective study that sought to identify clinical factors contributing to the development of in-stent restenosis in the carotid arteries, to profile the patients at greatest risk, and to review the treatment modalities evolved from our experience.

Methods:

Between December 2000 and April 2003, 195 carotid angioplasty/stenting (CAS) procedures (12 bilateral) were performed in 183 patients (131 men; median age 65.9 years, interquartile range 55.2–72.7). Stenting for de novo stenoses was performed in 119 (61%) carotid arteries; 76 (39%) vessels were treated for postsurgical restenosis. Nearly two thirds of the patients (117, 64%) were symptomatic. Patients were evaluated at 3 and 6 months and at 6-month intervals thereafter with duplex ultrasonography. Angiography was used to confirm any recurrent lesion detected on the ultrasound scan.

Results:

Overall perioperative neurological complications included 4 (2.2%) minor strokes, 1 (0.5%) intracranial hemorrhage, and 1 (0.5%) major stroke; both patients with major neurological complications died at 5 and 12 days, respectively, after the procedure. During the 12.5-month follow-up (range 0–27.2), 3 non-procedure-related late deaths and another 9 (4.9%) neurological events occurred (2 strokes and 7 transient ischemic attacks). In-stent restenosis after CAS was present in 10 (5.2%) of 193 carotid arteries (9/181 patients) in follow-up; all but 1 artery had been treated for postsurgical restenosis. All lesions were treated secondarily with endovascular procedures. Statistical analysis demonstrated that postsurgical restenosis was the only predictive factor for the development of in-stent restenosis (OR 15.5, 95% CI 2.05 to 125.6, p = 0.001) in this cohort.

Conclusions:

The present study, far from being exhaustive on the subject, indicates that patients who develop restenosis after carotid endarterectomy are also prone to develop restenosis after CAS; moreover, although strongly recommended for postsurgical restenosis, CAS carries a greater risk of in-stent restenosis in this subgroup, thus reducing the benefits of this procedure.

High-Risk Factors in Symptomatic Patients Undergoing Carotid Artery Stenting With Distal Protection

BACKGROUND:

Demographics and vascular anatomy may play an important role in predicting periprocedural complications in symptomatic patients undergoing carotid artery stenting (CAS).

OBJECTIVE:

To predict factors associated with increased risk of complications in symptomatic patients undergoing CAS and to devise a CAS scoring system that predicts such complications in this patient population.

METHODS:

A retrospective study was conducted that included patients who underwent CAS for symptomatic carotid stenosis during a 3-year period. Demographics and anatomic characteristics were subsequently correlated with 30-day outcome measures.

RESULTS:

A total of 221 patients were included in the study. The cumulative rate of periprocedural complications was 7.2%, including stroke (3.2%), myocardial infarction (3.2%), and death (1.4%). Renal disease increased the risk of all complications. National Institutes of Health Stroke Scale score ≥10 at presentation, difficult femoral access, and diseased calcified aortic arch increased the risk of stroke and all complications. Type III aortic arch correlated with increased risk of stroke. Pseudo-occlusion and concentric calcification of the carotid artery increased the risk of myocardial infarction, death, and all complications. Carotid tortuosity and anatomy hostile to the deployment of distal protection devices increased the risk of stroke, myocardial infarction, death, and all complications.

CONCLUSION:

Our results suggest that CAS should be avoided in patients with multiple anatomic risk factors. High presenting National Institutes of Health Stroke Scale score and renal disease also increase the complication risk. The CAS scoring system devised here is simple, reproducible, and clinically valuable in predicting complications risk in symptomatic patients undergoing CAS.

Carotid artery pseudoaneurysm as a complication of carotid artery stenting

Carotid artery stenting (CAS) has been adopted more in the treatment of carotid artery stenosis recently. The vast majority of studies about this procedure have concentrated mainly on the short- and long-term clinical complications, that is, stroke, myocardial infarction, and restenosis. However, mechanical complications including both stent fracture and carotid pseudoaneurysm are under-reported. In the present report, we present a patient with a common carotid artery psuedoaneurysm as a complication of CAS.

Early outcomes after carotid angioplasty with stenting performed by neurologists

AIMS

To evaluate the results of carotid artery angioplasty and stenting (CAS) in treating extracranial carotid artery stenosis performed by neurologists in our center and compare the results with other large published series.

MATERIALS AND METHODS

Data for all patients who underwent CAS from January 2003 through November 2007, was retrieved from the Nanjing Stroke Registry. Perioperative and post-procedural complications within 30 days following stenting were analyzed and compared with that from other series. A total number of 75 patients were enrolled, with a mean age of 65.9 ± 8.8 years, and 64 (85.3%) of them were male.

RESULTS

Procedural success was achieved in 74 patients (98.7%). Pre-treatment stenosis was 73.8 ± 14.9 and post-treatment residual stenosis was less than 10%. Thirty-four patients (45.3%) had bilateral carotid artery disease and seven (9.3%) had tandem stenosis. The neurological complication rate was 3.9% (one major and two minor strokes). Bradycardia in four (5.3%) and hypotension in 13 (17.3%) were observed during procedures. Using the Fischer's exact t test, the complication rate compared with the large published series did not reveal any statistically significant difference (P > 0.05).

CONCLUSIONS

We conclude that neurologists, with adequate training, can develop and add this technical skill to the existing cognitive skill of vascular neurology and safely perform stenting.

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.

Refractory In-stent Restenosis Following Carotid Artery Stenting: A Case Report and Review of Operative Management

In-stent restenosis following carotid artery stenting is a challenging problem that vascular surgeons will likely encounter with increasing frequency. The following describes a patient who developed progressive in-stent restenosis 3 years after carotid artery stenting, which was treated with operative therapy after failed balloon angioplasty. A review of the literature describing surgical approaches to the treatment of in-stent restenosis was also performed.

Follow-up results of carotid angioplasty with stenting as assessed by duplex ultrasound surveillance

BACKGROUND

Carotid artery stenting (CAS) has become an alternative modality to carotid endarterectomy (CEA) for the treatment of carotid occlusive disease. We report a retrospective review of our institution's experience with CAS versus CEA.

METHODS

Postprocedure surveillance duplex, recurrent symptoms, postprocedure strokes, progression of lesions, and rates of re-operation were analyzed in 46 patients who underwent CAS and 48 patients who underwent CEA. The mean length of follow-up evaluation was 13 months. All CAS procedures included neuroprotection devices.

RESULTS

Statistically significant differences in progression to critical restenosis (2% vs 2%, P = 1.0), rate of subsequent symptoms or stroke (2% vs 10%, P = .1), or rate of re-interventions were not observed between CAS and CEA groups (2% vs 4%, P = .98). Total mortality (0% vs 2%, P = .33), and the occurrence of major adverse events (2% vs 10%, P = .18) also were not significantly different in the CAS compared with the CEA patients. The average rate of increase in internal carotid velocity at 6 to 12 months (-1% vs 1.1%, P = NS) and 12 to 24 months (-5% vs -6.5%, P = NS) also were equivalent.

CONCLUSIONS

Our observed results indicate that CAS may be performed with comparable clinical outcomes and durability of repair comparable with CEA.

Current status of carotid artery stenting

This Clinical Update summarizes the results of larger case series, industry-sponsored registries, and randomized trials of carotid artery stenting (CAS). In >20 case series that studied >24,000 patients undergoing CAS, 51% of patients were symptomatic, most procedures (97%) resulted in successful stent deployment, and 30-day stroke rates varied from 1% to 8%, with a trend toward lower rates as experience and embolic protection device (EPD) use increased. In 12 industry-sponsored registries (none were published in peer-reviewed journals), 30-day stroke rates varied from 2% to 7%, and 30-day combined adverse events, including stroke, death, and myocardial infarction, were 3% to 9%. More than 12 randomized trials comparing CAS and carotid endarterectomy (CEA) have been initiated since 1998. Results have varied over time, depending on the population studied and the technology used. However, the largest and most recent results of the completed SAPPHIRE trial in high-risk patients undergoing CAS with the use of EPDs demonstrated that CAS is at least not inferior to CEA, with a 1-year combined adverse event rate of 12% for CAS and 20% for CEA (P = .05). Other ongoing trials will address not only whether CAS could be superior to CEA in high-risk patients but also, more importantly, whether CAS is beneficial in other subgroups, such as low-risk and asymptomatic patients.

Assessment of short-term outcomes for protected carotid angioplasty with stents using recent evidence

BACKGROUND

Carotid artery stenosis is an important risk factor and etiology of stroke. Carotid endarterectomy (CEA) is the gold standard for the treatment of carotid artery stenosis; however, there are potential benefits to adopting the use of carotid artery stenting (CAS) with protection devices. A number of large protected CAS (PCAS) trials are underway, but final results are still several years away. In the interim, numerous PCAS studies have recently been published, and the aim of this study was to combine the published results and examine the outcomes and safety of PCAS.

METHODS

Electronic, manual, and bibliographic searches of PubMed and PreMedline were conducted. Proportion differences were calculated for the periprocedural (30-day) outcomes of any stroke and any stroke or death.

RESULTS

More than 400 articles were identified. Only 26 studies met the inclusion criteria, resulting in the inclusion of 2,992 patients treated with PCAS. Within this patient group, the pooled perioperative PCAS rate of any type of stroke was 2.4% +/- 0.3% (95% confidence interval [CI]). The 30-day minor stroke rate was 1.1% +/- 0.2% (95% CI), and the 30-day major stroke rate was 0.6% +/- 0.2% (95% CI). The 30-day mortality rate was 0.9% +/- 0.4% (95% CI).

CONCLUSION

This study demonstrates relatively low rates of reported perioperative adverse events in PCAS. Selective use of PCAS to treat carotid artery stenosis in those at highest risk for surgical complications is appropriate until the randomized trials of CEA vs PCAS provide concurrent short- and long-term outcome data.

Systematic Review of Early Recurrent Stenosis After Carotid Angioplasty and Stenting

BACKGROUND AND PURPOSE

Carotid angioplasty and stenting (CAS) has emerged as a potential alternative to endarterectomy (CEA) for the treatment of carotid artery disease. Aside from the periprocedural complication rates, the benefits of CAS will be affected by the incidence of recurrent carotid stenosis.

METHODS

We conducted a systematic analysis of all peer-reviewed studies reporting on the rate of restenosis (> or =50%) after CAS based on duplex ultrasound or angiography that were published between January 1990 and July 2004. We identified 34 studies that reported on a total of 4185 patients with a follow-up of 3814 arteries over a median of 13 months (range, 6 to 31 months). The ultrasound criteria and the lower thresholds for defining a recurrent stenosis were very heterogeneous.

RESULTS

The cumulative restenosis rates after 1 and 2 years were approximately 6% and 7.5% in those studies, which used a lower restenosis threshold > or =50% to 70% and approximately 4% in the first 2 years after CAS in those studies, which used a lower restenosis threshold >70% to 80%.

CONCLUSIONS

In reviewing the current literature, the early restenosis rates after CAS compare well with those reported for CEA. However, this analysis of the peer-reviewed literature also indicates that the early restenosis rates after CAS might be higher than previously suggested in observational surveys. Therefore, an active follow-up of all stented arteries seems to be warranted. Moreover, the bulk of endovascular data are derived from small studies with short follow-up periods so that the long-term durability of CAS still needs to be established in large trials. Ideally, these studies should use a clear and uniform definition of restenosis and identical follow-up schedules.

Utility of covered stents for extracranial internal carotid artery stenosis

To our knowledge, the utility of coronary covered stents in the treatment of atherosclerotic carotid artery stenosis has not been defined in the English-language literature. Covered stents may prevent microembolic complications in select atherosclerotic carotid lesions, as they exclude the atherosclerotic lesion from the circulation by pressing the plaque against the vessel wall. Our early clinical experience has shown that use of these stents can be a therapeutic option in select cases of atherosclerotic stenosis of the cervical internal carotid artery.

Safety and durability of redo carotid operation: an 11-year experience

PURPOSE

With the recent emergence of carotid stenting in the management of carotid disease, the role of surgery has been challenged, particularly for recurrent carotid stenosis. This study was undertaken to determine the safety and durability of redo carotid operation (RCO) for recurrent stenosis.

METHODS

A retrospective review identified 64 consecutive patients who underwent 66 RCOs between 1990 and 2000. There were 33 males (52%) and 31 females, with a mean age of 68.2 years (range, 38-84 years). The mean interval from the primary carotid surgery to RCO was 77.5 months (range, 1-292 months). Operative indications were severe asymptomatic stenosis in 33 cases (50%), transient ischemic attacks (TIA) or amaurosis fugax in 25 (38%), recent stroke in 6 (9%), and nonhemispheric symptoms in 1. Two operations were tertiary carotid reconstructions. A total of 56 (85%) patch angioplasties were performed, 49 with vein and 6 with synthetic material. Primary closure was performed in three cases (5%), whereas interposition grafts were required in eight (12%). Complete follow-up was available in 59 patients (92%) and averaged 4.3 years (range, 0.2-12.9 years); 97% of patients underwent follow-up duplex scanning.

RESULTS

There were no operative deaths and only two operative strokes (3.1%). Permanent cranial nerve deficit occurred in one patient (1.5%). Late stroke occurred in five patients: four ipsilateral and one contralateral. Kaplan-Meier estimates for 5- and 10-year stroke-free survival were 92% and 74%, and for overall survival were 72% and 50%. Duplex scanning detected significant recurrent carotid stenosis (>80%) or occlusion in six cases (9%) at a mean follow-up of 4.1 years. Kaplan-Meier estimates for freedom from recurrent stenosis of >80% were 94% and 86% at 5 and 10 years.

CONCLUSIONS

RCO for recurrent carotid stenosis can be performed safely with excellent protection from stroke and long-term durability. These data provide a standard against which the results of carotid stenting can be compared.

Treatment of combined coronary and carotid artery disease

PURPOSE OF REVIEW

The purpose of this review is to evaluate the current indications and results of treatment of combined coronary and carotid disease. Synchronous carotid stenosis in patients with coronary artery disease poses a management challenge in patients with advanced atherosclerosis.

RECENT FINDINGS

Recent case series continue to demonstrate concomitant coronary and carotid disease with significant carotid stenosis greater than 70% in approximately 8% of patients evaluated for coronary artery bypass grafting. Surgical management options include staged operations addressing the carotid stenosis first, reverse staged operations addressing the coronary disease first, and combined synchronous operations addressing both territories during the same anesthetic. Recent reports demonstrate safety and acceptable risks with each operative approach. Lower trends in stroke rates were noted following staged procedures when compared with combined procedures. However, several metaanalyses showed no significant difference in rates of combined morbidity and mortality for all three strategies. Total morbidity and mortality risks for combined disease tended to be higher than for isolated coronary artery bypass grafting or carotid endarterectomy procedures performed for disease in a single vascular territory.

SUMMARY

Despite a large volume of data present in the literature, the treatment indications and surgical options remain controversial. We currently advocate treatment of symptomatic territory first in favor of staged procedures and reserve combined procedures for patients with critical stenosis or symptoms in both territories.

Contemporary management of "high-risk" patients with carotid stenosis

The concept of a "high-risk" carotid endarterectomy patient has been suggested in an effort to justify the application of carotid angioplasty and stenting outside of clinical trials. Contemporary results of carotid endarterectomy in this subgroup of patients would argue against the existence of a high-risk patient. Until randomized prospective trials establish the role of carotid angioplasty and stenting in carotid bifurcation disease, this new technology should be restricted to recurrent and radiation-induced disease.

Controversies in carotid stenting

Endovascular therapies are now commonly used in many vascular sites. However, the role for carotid angioplasty and stenting (CAS) remains an unproven therapy with some potential benefits. Initial results of CAS were worse than the surgical standard of carotid endarterectomy (CEA) and did not meet American Heart Association guidelines. However, recent improvements have resulted in improved stroke morbidity rate that may approach that of CEA. Specifically, the embolic problem associated with CAS has been reduced with embolic protection devices, but the ultimate effect of these protection devices remains uncertain. Initial comparison studies of CAS to CEA showed an unacceptably high stroke morbidity rate in the CAS group. As a result, multiple randomized clinical trials have been initiated to compare the results of CAS with embolic protection to that of CEA. While these studies are underway, the authors advocate a careful application of CAS to be used as a complementary tool for the carotid surgeon to use in special circumstances when CEA cannot be undertaken with acceptable morbidity. Furthermore, since the reported stroke morbidity rate of CAS exceeds the AHA recommendation for treatment of asymptomatic patients, most nonsurgical patients with asymptomatic disease should be treated with medical therapy.