Ming W. Liu

Immediate and Late Clinical Outcomes of Carotid Artery Stenting in Patients With Symptomatic and Asymptomatic Carotid Artery Stenosis

Background—Carotid stenting is a less invasive percutaneous procedure than carotid endarterectomy for the treatment of carotid stenosis. Reports suggest that it can be performed with periprocedural complication rates similar to those of carotid endarterectomy. The purpose of this study was to determine short- and long-term outcomes in the largest prospective cohort of carotid stenting patients. Methods and Results—This study followed 528 consecutive patients (604 hemispheres/arteries) undergoing carotid stenting. There was a 0.6% (n=3) fatal stroke rate and 1% (n=5) nonstroke death rate at 30 days. The major stroke rate was 1% (n=6), and the minor stroke rate was 4.8% (n=29). The overall 30-day stroke and death rate was 7.4% (n=43). Over the 5-year study period, the 30-day minor stroke rate improved from 7.1% (n=7) for the first year to 3.1% (n=5) for the fifth year (P<0.05 for trend). The best predictor of 30-day stroke and death was age ≥80 years. After the 30-day period, the incidence of fatal and nonf...

Predictors of Stroke Complicating Carotid Artery Stenting

BACKGROUND The evolving technique of carotid stenting is being evaluated as an alternative to endarterectomy. Identification of the factors that predispose a patient to neurological complications would facilitate further refinement of the technique and optimize patient selection. METHODS AND RESULTS We analyzed the impact of various clinical, morphological, and procedural determinants on the development of procedural strokes in 231 patients who underwent elective (primary) stenting of 271 extracranial carotid arteries. The mean age of the patients was 68.7+/-10 years, 165 (71%) were males, and 139 (60%) had symptoms attributed to the lesion treated. This series represented a high-risk subset with 164 patients (71%) having significant coronary artery disease, 91 (39%) having bilateral disease, and 28 (12%) having contralateral carotid occlusion. Of the treated vessels, 59 (22%) had prior carotid endarterectomy, 66 (24%) had ulcerated plaques, and 87 (32%) had calcified lesions. Only 37 treated vessels (14%) would have been eligible for inclusion in the North American Symptomatic Carotid Endarterectomy Trial (NASCET). There were 17 (6.2%) minor and 2 (0.7%) major strokes during and within 30 days of the procedure. NASCET-eligible patients had a low (2.7%) risk of procedural strokes after carotid stenting. The results of multivariate analysis revealed advanced age (P=.006) and presence of long or multiple stenoses (P=.006) as independent predictors of procedural strokes. CONCLUSIONS During this procedural developmental phase of carotid stenting, neurological complications were highly dependent on patient selection. Advanced age and long or multiple stenoses were independent predictors of procedural stroke.

Elective Stenting of Symptomatic Basilar Artery Stenosis

BACKGROUND AND PURPOSE Percutaneous angioplasty of the intracranial arteries still carries the risk of dissection, with acute closure and embolization. Stenting has been shown to improve the safety and durability of angioplasty in every circulatory bed in which it has been applied. However, stenting of the intracranial arteries has been limited by the availability of stents that can be reliably deployed intracranially. METHODS Twelve patients underwent elective stenting of the basilar artery after episodes of vertebrobasilar ischemia. In all patients, either medical therapy had failed or the patient had a contraindication for long-term anticoagulation. Information from independent neurological examinations, quantitative angiography, and clinical follow-up was collected. Differences between pretreatment and posttreatment degree of stenoses were subjected to 1-way ANOVA for repeated measures. RESULTS There were 10 men and 2 women, all white, aged 40 to 82 years (mean age, 62.6 years). Stent placement was successful in all patients, leading to statistically significant changes in the degree of stenosis, from 71. 4% (range, 53% to 90%) to 10.3% (range, 0% to 36%) (P<0.0001). There were no deaths, stent thromboses, perforations, ruptures, or myocardial infarctions. Clinical follow-up was available for 0.5 to 16 months (mean, 5.9 months). One patient had nonspecific symptoms, and another had a transient ischemic attack. All other patients remained asymptomatic. CONCLUSIONS Elective stenting of the basilar artery is feasible, with minimal risk to the patient. Its impact on long-term stroke prevention and its durability are unknown and will require further study.

Safety, efficacy, and durability of carotid artery stenting for restenosis following carotid endarterectomy: a multicenter study.

Purpose: To present the results of a multicenter registry established to collect data on carotid stent procedures in patients with restenosis following carotid endarterectomy. Methods: The procedural details, outcomes, and late follow-up results were collected from 14 centers in the United States. Thirty-day and late stroke and death rates were analyzed. Results: Three hundred and thirty-eight patients (201 men; 71 ± 8 years) underwent carotid stenting in 358 arteries. The average duration from carotid endarterectomy was 5.5 ± 7.3 years. Sixty-one percent of the patients were asymptomatic. The overall 30-day stroke and death rate was 3.7%. The minor stroke rate was 1.7% (6/358), and the major nonfatal stroke rate was 0.8% (3/358). The fatal stroke rate was 0.3% (1/358), and the nonstroke-related death rate was 0.9% (3/338). There was 1 (0.3%) fatal and 1 (0.3%) nonfatal stroke during the follow-up period. The overall 3-year rate of freedom from all fatal and nonfatal strokes was 96% ± 1% (±SE). Conclusions: Carotid artery stenting can be performed in patients with restenosis following carotid endarterectomy with 30-day complication rates comparable to those of most published studies on repeat carotid endarterectomy. Results of late follow-up suggest that this technique is durable and efficacious.

Predictors of Thrombotic Complications After Placement of the Flexible Coil Stent

The balloon-expandable, stainless steel, flexible coil stent is a useful device for managing acute or threatened closure after percutaneous transluminal coronary angioplasty.1–5 Use of the device is associated with thrombosis of the stented vessel in a small but important group of patients.3,6–10 The clinical, angiographic, and procedural factors associated with stent thrombosis with this device are still unknown. The objective of this study was to define predictors of stent thrombosis occurring within the ftrst month after stenting with this device.

Carotid stenting for severe radiation-induced extracranial carotid artery occlusive disease.

PURPOSE To present our experience with carotid artery stenting as an alternative treatment to endarterectomy in patients with radiation-induced carotid artery occlusive disease. METHODS AND RESULTS Fourteen patients (10 males; mean age 61 years, range 52 to 79) underwent percutaneous stenting of 15 carotid arteries for severe radiation-induced extracranial stenoses. Technical success was achieved in all patients, with reduction of the mean stenosis from 77% +/- 6% to 8% +/- 2%. In 2 patients, ipsilateral vertebral artery lesions were stented concomitantly. One patient had a minor stroke after the procedure but recovered fully in 2 days. No other complications were encountered. Nine (64%) patients had 6-month follow-up imaging (angiography or duplex scanning) that showed no evidence of restenoses (obstruction > or = 50%). At 18 +/- 2 months, 3 (21%) patients had died from unrelated causes. No neurological events occurred, and no repeat carotid artery interventions were required in the remaining patients. CONCLUSIONS Carotid stenting is an effective treatment option for severe radiation-induced carotid artery occlusive disease.

Utilization of the Coronary Balloon-Expandable Coil Stent Without Anticoagulation or Intravascular Ultrasound

BACKGROUND The balloon-expandable coil stent has been proved effective in the management of acute and threatened closure after coronary balloon angioplasty and has been shown to reduce restenosis in patients with suboptimal results after coronary balloon angioplasty. Coronary artery stenting has been limited by the occurrence of stent thrombosis and comorbidity related to anticoagulation. This study was undertaken to determine whether anticoagulation may be removed from poststenting protocols, thus reducing comorbidity without increasing stent thrombosis. METHODS AND RESULTS Between September 1994 and May 1995, 369 patients received balloon-expandable coil stents in native coronary arteries at our institution. Of these patients, 216 were selected for a protocol of aspirin and ticlopidine (for 1 month) without anticoagulation. Eligibility for this protocol followed satisfaction of certain procedural and angiographic criteria. These criteria included adequate coverage of intimal dissections, absence of residual filling defects, and normal (TIMI grade 3) flow in the stented vessel after high-pressure balloon inflations. Intravascular ultrasound was not used to guide stent deployment. The stenting procedure was planned in 37% of patients and unplanned in 63% of patients, including 25 (12%) for acute or threatened closure. During the 30-day follow-up period, stent thrombosis occurred in 2 patients (0.9%), there was 1 death (0.5%), and 2 patients (0.9%) underwent coronary bypass surgery. Vascular access-site complications occurred in 4 patients (1.9%), and bleeding that required blood transfusion occurred in 4 patients (1.9%). CONCLUSIONS Patients who receive the coronary balloon-expandable coil stent with optimal angiographic results without intravascular ultrasound guidance can be managed safely with a combination of aspirin and ticlopidine without anticoagulation.

Comparison of aspirin alone versus aspirin plus ticlopidine after coronary artery stenting

This prospective nonrandomized study was performed comparing aspirin alone (n = 46) versus aspirin and ticlopidine (p = 338) following native coronary artery stenting. There were significantly more stent thrombosis events in the aspirin-only group than in the aspirin and ticlopidine group (6.5% vs 0.9%, p = 0.02) and significantly more Q-wave myocardial infarctions and cardiac-related deaths in the aspirin-only group than in the aspirin and ticlopidine group (6.5% vs 0%, p = 0.002 and 4.4% vs 0.3% p = 0.02, respectively).

Efficacy of coronary stenting in the management of cardiac allograft vasculopathy.

We undertook a study to determine the efficacy of stents in reducing restenosis in cardiac allograft vasculopathy. The result shows that coronary stenting significantly reduces restenosis in cardiac allograft vasculopathy compared with balloon angioplasty alone.

Immediate and late outcomes of subclavian artery stenting.

Stenting for subclavian artery occlusive disease is being increasingly utilized. To determine the immediate and late outcome of subclavian artery stenting, we studied 38 consecutive patients in whom the procedure was attempted. Technical and clinical success was achieved in 35 patients without complications. Failures occurred only in completely occluded arteries. Late clinical success was demonstrated in 31 patients. Three patients had recurrent symptoms. Two had angiographic restenosis within 4 months of the procedure; both were successfully redilated. The third patient had a new lesion, which was successfully stented. One patient died from lung cancer 10 months after the procedure. We conclude that stenting for subclavian artery occlusive disease has favorable immediate and late clinical outcomes and may be considered as a primary therapy. Cathet. Cardiovasc. Intervent. 46:169–172, 1999.