Technical aspects and current results of carotid stenting

Carotid Surgery Following Previous Carotid Endarterectomy Is Safe and Effective

With the perceived high risk of repeat carotid surgery, carotid angioplasty and stenting have been advocated recently as the preferred treatment of recurrent carotid disease following carotid endarterectomy. An experience with the operative treatment of recurrent carotid disease to document the risks and benefits of this procedure is presented. A review of a prospectively acquired vascular registry over a 10-year period (Jan. 1990-Jan. 2000) was undertaken to identify patients undergoing repeat carotid surgery following previous carotid endarterectomy. All patients were treated with repeat carotid endarterectomy, carotid interposition graft, or subclavian-carotid bypass. The perioperative stroke and death rate, operative complications, life-table freedom from stroke, and rates of recurrent stenosis were documented. During the study period 56 patients underwent repeat carotid surgery, comprising 6% of all carotid operations during this period. The indication for operation was symptomatic disease recurrence in 41 cases (73%) and asymptomatic recurrent stenosis? 80% in 15 cases (27%). The average interval from the prior carotid endarterectomy to the repeat operation was 78 months (range 3 weeks-297 months). The operations performed included repeat carotid endarterectomy with patch angioplasty in 31 cases (55%), interposition grafts in 19 cases (34%), and subclavian-carotid bypass in 6 cases (11%). There were three perioperative strokes with one resulting in death for a perioperative stroke and death rate of 5.4%. One minor transient cranial nerve (CN IX) injury occurred. Mean follow-up was 29 months (range, 1-1 16 months). Life-table freedom from stroke was 95% at 1 year and 90% at 5 years. Recurrent stenosis (? 80%) developed in three patients (5.4%) during follow-up, including one internal carotid artery occlusion. Two patients (3.6%) underwent repeat surgery. Repeat surgery for recurrent cerebrovascular disease following carotid endarterectomy is safe and provides durable freedom from stroke. Most patients are candidates for repeat endarterectomy with patching, but interposition grafting is often required. These results strongly support the continued role of repeat carotid surgery in the treatment of recurrent carotid disease.

Improving endothelial healing with novel chimeric mitogens

BACKGROUND

Chimeric proteins may be used to direct cell-specific activity. Heparin-binding growth-associated molecule (HBGAM) binds to cell receptors that are relatively more robust on endothelial cells, and it may confer endothelial cell selectivity to potent angiogens such as fibroblast growth factor-1 (FGF-1).

METHODS

By ligating fibroblast growth factor or its potent mutant, S130K, to HBGAM, we tested their effect on re-endothelialization after angioplasty injury by using a canine model.

RESULTS

Both HBGAM/S130K- and HBGAM/FGF-1-treated arteries had increased neointimal mitotic index and re-endothelialization rates at 30 days compared with control arteries without inducing a significant increase in the neointimal thickness or the ratio of neointimal to medial thickness between treatment and control groups.

CONCLUSION

HBGAM/S130K and HBGAM/FGF-1 facilitates endothelial healing without myointimal thickening after canine carotid artery balloon angioplasty injury. Application of these growth factors in fibrin glue may improve endothelialization clinically after angioplasty or endarterectomy.

Cardiovascular gene delivery: The good road is awaiting

Atherosclerotic cardiovascular disease is a leading cause of death worldwide. Despite recent improvements in medical, operative, and endovascular treatments, the number of interventions performed annually continues to increase. Unfortunately, the durability of these interventions is limited acutely by thrombotic complications and later by myointimal hyperplasia followed by progression of atherosclerotic disease over time. Despite improving medical management of patients with atherosclerotic disease, these complications appear to be persisting. Cardiovascular gene therapy has the potential to make significant clinical inroads to limit these complications. This article will review the technical aspects of cardiovascular gene therapy; its application for promoting a functional endothelium, smooth muscle cell growth inhibition, therapeutic angiogenesis, tissue engineered vascular conduits, and discuss the current status of various applicable clinical trials.

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.

Technical challenges in a program of carotid artery stenting

OBJECTIVES

Successful carotid artery stenting (CAS) involves gaining access to the common carotid artery, characterizing and crossing the lesion, deploying an anti-embolic device and stent, and retrieving the anti-embolic device. These steps are critical determinants of the complexity of the procedure. The frequency with which technical challenges are encountered during CAS is ill-defined. The purpose of this investigation was to review the incidence and types of technical challenges encountered during CAS and determine their effect on outcome.

METHODS

Data were prospectively collected for 194 consecutive CAS procedures (177 patients) and separated into group 1, standard CAS technique, and group 2, procedures with technical challenges requiring modifications to the technique. Technical challenges were defined as difficult femoral arterial access (aortoiliac occlusive disease), complex aortic arch anatomy (elongated or bovine arch, deep takeoff of the innominate artery, tandem stenoses (CCA, innominate artery), difficult internal carotid artery anatomy (tortuosity, high-grade stenosis), and circumferential internal carotid artery calcification. The incidence of technical challenges, types of technical modifications required, and effect on outcomes were determined.

RESULTS

Fifty technically challenging situations (26%) were encountered in 194 CAS procedures (group 2), which required advanced technical skills. Standard methods were used in the other 144 procedures (group 1, 74%). No significant differences in 30-day stroke and death rates were noted between the groups (group 1, 3.1%; group 2, 2.0%; P = .564).

CONCLUSIONS

Twenty-six percent of the procedures required a modification in the standard technique for successful CAS. Circumferential calcification and severe tortuosity continue to be relative contraindications to CAS. Recognition of these technical challenges and increasing facility with the methods to manage them will enable expanded use of CAS without increased morbidity and mortality.

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.

[Evaluation of stent-protected angioplasty for theray of symptomatic stenoses of the carotid artery. SPACE and other randomized trials]

During recent years, stent-protected angioplasty of the carotid artery (SPAC) has become an alternative to endartectomy (CEA) in many centers. Despite many case reports, case series, and open records, it has not been proven that these therapeutical regimens are comparable regarding complication rates and long-term outcome. Until now, only three randomized trials were published on this theme, two of them only as abstracts. This is not sufficient for answering the question of whether SPAC is a good alternative to CEA. At present, four major, randomized, multicenter trials are being run (EVA3S in France, CREST in the US, ICSS in Great Britain and several other countries, and SPACE in Germany and Austria). About 7,300 patients will be included in these trials. At present, 24 centers are participating in the SPACE trial, recruiting about 350 patients. It has been prospectively agreed that EVA-3S, ICSS, and SPACE will combine their results after completion of initial randomization and follow-up to conduct a combined European meta-analysis of the data. Three to 5 years are needed until these trials' final results will be published. Until then, stent-protected angioplasty should be done only under the consideration that it has not been scientifically evaluated.

Early outcome of carotid angioplasty and stenting with and without cerebral protection devices: a systematic review of the literature

BACKGROUND

Carotid angioplasty and stenting (CAS) is increasingly being used for treatment of symptomatic and asymptomatic carotid artery disease (CAD). To evaluate the efficacy of cerebral protection devices in preventing thromboembolic complications during CAS, we conducted a systematic review of studies reporting on the incidence of minor stroke, major stroke, or death within 30 days after CAS.

SUMMARY OF REVIEW

We searched for studies published between January 1990 and June 2002 by means of a PubMed search and a cumulative review of reference lists of all relevant publications. In 2357 patients a total of 2537 CAS procedures had been performed without protection devices, and in 839 patients 896 CAS procedures had been performed with protection devices. Both groups were similar with respect to age, sex distribution, cerebrovascular risk factors, and indications for CAS. In many studies the periprocedural complication rates had not been presented separately for patients with symptomatic and asymptomatic CAD. The combined stroke and death rate within 30 days in both symptomatic and asymptomatic patients was 1.8% in patients treated with cerebral protection devices compared with 5.5% in patients treated without cerebral protection devices (chi2=19.7, P<0.001). This effect was mainly due to a decrease in the occurrence of minor strokes (3.7% without cerebral protection versus 0.5% with cerebral protection; chi2=22.4, P<0.001) and major strokes (1.1% without cerebral protection versus 0.3% with cerebral protection; chi2=4.3, P<0.05), whereas death rates were almost identical (approximately 0.8%; chi2=0.3, P=0.6).

CONCLUSIONS

On the basis of this early analysis of single-center studies, the use of cerebral protection devices appears to reduce thromboembolic complications during CAS. These technical aspects should be taken into account before the initiation of further randomized trials comparing CAS with carotid endarterectomy.

Systematic versus selective stent placement after superficial femoral artery balloon angioplasty: a multicenter prospective randomized study

PURPOSE

Outcome with selective or systematic stenting with the Palmaz vascular stent was compared in patients with limb-threatening ischemia or persistent disabling claudication despite medical therapy, with less than 7 cm stenosis or occlusion of the superficial femoral artery.

METHODS

This was a multicenter prospective randomized trial with centralized allocation of treatment and independent review of vascular events. The primary end point was presence of more than 50% stenosis at 1-year angiographic follow-up. Secondary end points were survival; occurrence of vascular events in the treated leg; and number of failed procedures, defined as more than 50% stenosis or death at 1 year.

RESULTS

Two hundred twenty-seven patients were enrolled in the study, 112 in the selective stent group, and 115 in the systematic stent group. Seventeen patients (15%) in the selective stent group received a stent after suboptimal results of percutaneous transluminal angioplasty. Angiograms for 140 patients were available at 1-year follow-up and demonstrated no statistical difference between the two groups; more than 50% stenosis of the dilated site was noted in 21 of 65 patients (32,3%) in the selective stent group and 26 of 75 patients (34.7%) in the systematic stent group (P =.85, Fisher exact test). Survival in the percutaneous transluminal angioplasty and stent groups was, respectively, 92% and 96% at 1 year, 89% and 93% at 2 years, and 82% and 80% at 4 years (P =.40, log-rank test). Survival free of new vascular events in the treated limb was 77% and 65% at 1 year, 70% and 53% at 2 years, and 57% and 44% at 4 years (P =.017, log-rank test). Number of failed procedures at 1 year was 29 of 86 (33%) and 30 of 89 (34%) (P = 0.9).

CONCLUSION

Systematic stenting of short stenosis or occlusion of the superficial femoral artery is not justified. Palmaz vascular stent placement should be reserved for use in patients with suboptimal results of balloon angioplasty.

Intermediate follow-up of carotid artery stent placement

BACKGROUND

Carotid artery stent placement (CAS) is becoming more popular among various specialties for the treatment of primary and recurrent carotid artery disease. The morbidity associated with this procedure is improving but the intermediate- and long-term follow-up remains unknown. We report our restenosis rates and follow-up associated with CAS.

METHODS

Thirty-one interventions on 29 patients from May 1998 to January 2002 were reviewed. All patients have undergone serial follow-up using Doppler ultrasound at 3 and 6 months and every 6 months thereafter. Ten interventions (32%) were performed on patients with recurrent carotid artery disease and 21 (68%) on patients with primary disease.

RESULTS

Five periprocedural complications occurred (transient ischemic attack, n = 3; major stroke, n = 1; immediate intrastent restenosis requiring lysis, n = 1) for a total immediate complication rate of 16%. No deaths occurred. Follow-up was achieved in all 29 patients (mean 28 months; range 20 to 46). Twenty-seven patients (29 vessels; 94%) remain asymptomatic with less than 50% stenosis. Two vessels (6%) have been found to have a critical restenosis of greater than 90%. Both patients were symptomatic from their recurrence (transient ischemic attack, n = 1; acute stroke, n = 1). Cumulative major stroke and death rate including all follow-up was 6%.

CONCLUSIONS

CAS can be performed with an acceptable stroke/death rate (3%) in a properly selected patient population. In our small series of patients, the restenosis rate at a mean of 28 months after CAS is 6%.

Carotid artery stenting in older patients: is age a risk factor for poor outcome?

PURPOSE

To assess the impact of age on technical success and complications of carotid stenting in a prospective single-center cohort study.

METHODS

One hundred eleven consecutive patients (74 men; median age 70 years) with >or=70% symptomatic (n=33) or >or=90% asymptomatic (n=78) internal carotid artery (ICA) stenosis underwent carotid artery stent implantation. Primary technical success and periprocedural complications were compared in patients aged >75 years (n=28) to patients <75 years (n=83).

RESULTS

Patient groups below and above 75 years compared well with respect to baseline demographic and clinical data. Successful stenting was achieved in 108 (97%) patients. The combined neurological complication rate was 7% (n=8), with 1 (1%) major stroke, 1 (1%) minor stroke, and no 30-day mortality. Technical angiographic complications occurred in 8 (7%) patients. No significant differences between patients >75 years and those <75 years were observed for primary success rates (100% [28/28] versus 96% [80/83]; p=0.8), overall complications (14% [4/28] versus 16% [13/83]; p=1.0), neurological complications (7% [2/28] versus 7% [6/83]; p=1.0), or technical complications (7% [2/28] versus 4% [3/83]; p=0.6).

CONCLUSIONS

Elective carotid stenting can be performed safely in older patients with several comorbidities. Patient age does not seem to be an independent risk factor for poor outcome after endovascular treatment of internal carotid artery stenosis.

Operative intervention for recurrent stenosis after carotid stent angioplasty: a report

Carotid artery angioplasty and stenting is gaining popularity, yet the natural history and optimal treatment for recurrent stenoses within stents are not known. Recurrent stenosis rates are not well characterized, with rates between 0 and 33% reported within the first year. Treatment of these lesions with repeat angioplasty may not be feasible or desirable, leading to operative interventions. We present two cases of asymptomatic high-grade in-stent restenosis treated successfully with carotid artery bypass using PTFE.

Stent placement in common carotid and internal carotid artery stenoses with use of an open transcervical approach in a patient with previous endarterectomy

In this article, a patient with extensive cerebrovascular disease who had previously undergone bilateral carotid endarterectomy and subsequent operative revision on the left side is described. The patient developed critical restenosis at the cephalic end of the previous left patch angioplasty as well as a severe stenosis of the left common carotid artery origin, which originated from a bovine aortic arch configuration. His right common and internal carotid arteries had become occluded. Endovascular treatment with two metallic stents was successfully performed through a surgical cutdown on the immediate supraclavicular portion of the left common carotid artery to establish antegrade and subsequently retrograde vascular access.