Management of in-sent restenosis after carotid artery stenting in high-risk patients

Influence of vessel size and tortuosity on in-stent restenosis after stent implantation in the vertebral artery ostium

PURPOSE

Percutaneous transluminal angioplasty and stenting is emerging as an alternative for treating atherosclerotic stenosis in the vertebral artery ostium. However, in-stent restenosis (ISR) still remains a critical issue to be addressed. Little is known about the relationship between anatomic characteristics of the artery and ISR after stent implantation. In this study, we have evaluated influential factors for ISR in a cohort of the patients with stenting in the vertebral artery ostium.

METHODS

Sixty-one patients with 63 symptomatic lesions in vertebral artery ostium treated with stenting were enrolled onto this study. An average of 12.5 months' clinical and angiographic follow-up results were analyzed retrospectively. The possible influential factors for ISR, including conventional risk factors of cerebrovascular diseases and morphological characteristics of target lesions, were evaluated by univariate and multivariate regression analysis.

RESULTS

Technical success was achieved in all 63 interventional procedures. Stenosis was reduced from (mean±standard deviation) 75.5±12% before to 1±3.6% after the procedure. During the mean 12.5-month angiographic follow-up, ISR was detected in 17 treated vessels (27.0%), with 2 treated arteries (3.2%) resulting in occlusion, and a stent fracture in 1 case (1.6%). Multivariate Cox regression analysis showed that the tortuosity of V1 (hazard ratio 3.54, P=0.01) and smaller diameter of the stent (hazard ratio 3.8, P=0.04) were independent predictors of ISR.

CONCLUSIONS

Angioplasty and stenting for symptomatic stenosis in the vertebral artery ostium stenosis seem to be feasible and effective. Tortuosity and smaller diameter may affect ISR after stent implantation.

Carotid artery interventions for restenosis after prior stenting: is it different from interventions of de novo lesions? Results from the carotid artery stent (CAS)--registry of the Arbeitsgemeinschaft Leitende Kardiologische Krankenhausärzte (ALKK)

OBJECTIVE

To compare characteristics and outcome of patients with re-stenoses after prior carotid artery stenting (CAS) treated with repeat carotid interventions (Re-CI) with CAS for de novo lesions.

BACKGROUND

The treatment of re-stenosis is a major problem in vascular interventions. Patients with re-stenoses after prior CAS treated with Re-CI are not well defined.

METHODS

We analyzed data from the prospective ALKK CAS Registry.

RESULTS

Out of 3,817 CAS procedures 95 were intended in 93 patients (2.5%) for a restenosis after prior CAS and 3,722 CAS in 3,655 patients (97.5%) for a de novo stenosis. There was no difference in age (p = 0.302) or distribution of gender (p = 0.545) between the two groups. Patients treated for a restenosis after CAS were less likely to be treated for a symptomatic lesion (22.7 vs. 40.1%, p = 0.001). Coronary heart disease (p = 0.017), peripheral arterial disease (p < 0.001) as well as diabetes mellitus (p = 0.004) were more prevalent in the restenosis group. Lesions were less complicated in restenosis patients, with less ulcers (7.4 vs. 19.9%, p = 0.003) and less severe calcifications (7.4 vs. 23.6%, p < 0.001). The intended interventions were more often not performed in the Re-CI group (9.5 vs. 3.3%; p = 0.001). In-hospital, the stroke or death rate was 0% in the Re-CI group as compared to 3.1% in the de novo group (p = 0.115).

CONCLUSIONS

Patients treated with Re-CI for repeat stenoses after prior CAS represent 2.5% of current CAS patients. Although representing a subgroup with more concomitant diseases, Re-CI seems to be associated with lower event rates as compared to CAS for de novo lesions.

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.

Fate of the external carotid artery following carotid interventions

OBJECTIVE

The external carotid artery (ECA) is an important collateral pathway for cerebral blood flow. Carotid artery stenting (CAS) typically crosses the ECA, while carotid endarterectomy (CEA) includes deliberate ECA plaque removal. The purpose of the present study was to compare the long-term patency of the ECA following CAS and CEA as determined by carotid duplex ultrasound.

METHODS

Duplex ultrasounds and hospital records were reviewed for consecutive patients undergoing CAS between February 2002 and April 2008, and were compared with those undergoing CEA in the same time period. Preoperative and postoperative ECA peak systolic velocities were normalized to the common carotid artery (CCA) as ECA/CCA ratios. A significant (80% or greater) ECA stenosis was defined as an ECA/CCA ratio of 4.0. A change of ratio by more than 1 was defined as significant. Data were analyzed using Student's t test and χ(2) analysis.

RESULTS

A total of 86 CAS procedures in 83 patients were performed (81 men, mean age 69.9 years). Among them, 38.4% of patients had previous CEA, 9.6% of whom had contralateral internal carotid artery occlusion. Sixty-seven CAS and 65 CEA patients with complete duplex data in the same time period were included in the analyses. There was no difference in the incidence of severe ECA stenosis on preoperative ultrasound evaluations. During a mean follow-up of 34 months (range four to 78 months), three postprocedure ECA occlusions were found in the CAS group. The likelihood of severe stenosis or occlusion following CAS was 28.3%, compared with 11% following CEA (P<0.025). However, 62% of CEA patients and 57% of CAS patients had no significant change in ECA status. Reduction in the patient's degree of ECA stenosis was observed in 9.4% of CAS versus 26.6% of CEA patients. Overall, immediate postoperative ratios of both groups were slightly improved, but there was a trend of more disease progression in the CAS group during follow-up.

CONCLUSION

CAS is associated with a higher incidence of post-procedure ECA stenosis. Despite the absence of neurological symptoms, a trend toward late disease progression of ECA following CAS warrants long-term evaluation.

Cutting balloon angioplasty in percutaneous carotid interventions

PURPOSE

To report a prospective feasibility study of cutting balloon angioplasty (CBA) applied in the predilation phase of carotid artery stenting (CAS) in highly calcified lesions.

METHODS

From January 2003 to February 2007, 178 consecutive patients (109 men; mean age 73.1+/-7.3 years) with highly calcified carotid lesions underwent CAS with CBA applied as a pre-specified strategy in the predilation phase of the procedure. All steps in the procedure were performed under cerebral filter protection. The cutting balloon ranged in diameter from 3 to 4 mm and was inflated at nominal pressures in the target lesion. Pre-CBA dilation with a low-profile coronary balloon was performed only when the cutting balloon was not able to cross the lesion. Selection of the filters and stents was at the operator's discretion. Primary endpoints were the all stroke and death rates at 30 days and 6 months. Secondary endpoints included cutting balloon success (positioning and full balloon inflation), CAS technical success (residual angiographic stenosis <30%), CAS procedural success (technical success and no complications), and in-hospital major complications.

RESULTS

Cutting balloon success was achieved in all 178 patients. In 32 (18.0%), pre-CBA dilation was necessary due to inability to cross the lesion with the cutting balloon initially. CAS technical success was achieved in all patients. One (0.6%) patient suffered transient neurological intolerance due to flow cessation from massive debris in the distal filter; this event was completely resolved after the filter was removed (CAS procedural success 99.4%). One patient suffered a major stroke at day 15 (0.6% 30-day all stroke and death rate). At the 6-month follow-up, 174 (97.7%) patients were evaluated; 1 patient died from myocardial infarction at day 35, and 2 patients died from non-neurological or cardiac causes at days 103 and 158. The cumulative all stroke and death rate was 2.2%.

CONCLUSION

These data suggest that CBA performed during the predilation phase of CAS in highly calcified lesion is a safe and useful method to prepare this lesion subset for stenting.

Cutting balloon angioplasty for carotid artery in-stent stenosis supported by three-dimensional rotational angiography with automated vessel analysis software

In-stent stenosis is a possible long-term complication of carotid artery stenting. A simple and safe technique of cutting balloon angioplasty is described for carotid in-stent stenosis. The stented vessel is imaged by three-dimensional (3D) rotational angiography, the acquired projection images are transferred to a workstation, and the stenotic lesion and implanted stent are reconstructed. The diameter of the implanted stent in the stenotic region is measured by automated analysis software. Cutting balloon angioplasty carries the risk of vessel injury by the cutting balloon microblades, but the implanted stent acts as a barrier to protect the vessel. Therefore, cutting balloon inflation up to the stent diameter is safe and results in maximal vessel dilation. The key to success is precise measurement of the stent diameter and choice of a cutting balloon catheter of the appropriate size. 3D rotational angiography provides high-quality images of the vasculature of a stented vessel and a reference for intervention based on absolute measurements. Cutting balloon angioplasty supported by 3D rotational angiography with automated vessel analysis software should be considered as a treatment strategy for high-grade carotid artery in-stent stenosis.

Cutting balloon angioplasty for carotid in-stent restenosis: case reports and review of the literature

Percutaneous stenting techniques are becoming more commonly used for treatment of carotid artery disease. One outcome of particular concern is in-stent restenosis. Indications for treatment of in-stent restenosis are not clearly defined. Use of traditional balloon angioplasty with or without stent placement is still considered the first option. Cutting balloon angioplasty has recently been used as an alternative treatment option for revascularization of in-stent restenosis with higher procedural success rates and without the use of additional stents. We report our experience with cutting balloon angioplasty in treating 2 patients with carotid in-stent restonosis, and review previous cases reported in the literature. A total of 16 patients have been treated with cutting balloon angioplasty. Among 11 patients for whom the clinical and angiographic information were available, 63% of patients were asymptomatic at the time of treatment, and more than 90% of patients showed either complete angiographic resolution or residual stenosis of less than 30%. Additional stent placement or angioplasty was required in only half of the patients, and 1 patient had recurrent stenosis. The review suggests that the procedure is safe and effective.

Recurrent carotid stenosis after CEA and CAS: diagnosis and management

Carotid endarterectomy (CEA) is the preferred method for cerebral revascularization in patients with symptomatic and asymptomatic high-grade extracranial carotid artery stenosis. Carotid artery stenting (CAS) has recently emerged as a less invasive alternative to endarterectomy. Carotid stenting has been demonstrated to be technically feasible and safe in high-risk patients. It has been approved as an acceptable method for revascularization in circumstances where CEA yields suboptimal results. While the final role of CAS in carotid revascularization will be determined on the basis of ongoing randomized trials, it is clear that stenting will continue to be performed in subgroups of patients with carotid stenosis. Therefore, it is anticipated that there will be a corresponding increase in the number of in-stent restenosis cases. Considerable controversy exists regarding the clinical significance, natural history, threshold for management, and appropriate intervention of recurrent carotid stenosis after endarterectomy and after stenting. This review analyzes current information on this important clinical problem and presents evidence-based recommendations for the diagnosis and management of recurrent carotid stenosis.

Duplex scan surveillance after carotid angioplasty and stenting: A rational definition of stent stenosis

OBJECTIVE

A duplex ultrasound (DUS) surveillance algorithm used after carotid endarterectomy (CEA) was applied to patients after carotid stenting and angioplasty (CAS) to determine the incidence of high-grade stent stenosis, its relationship to clinical symptoms, and the outcome of reintervention.

METHODS

In 111 patients who underwent 114 CAS procedures for symptomatic (n = 62) or asymptomatic (n = 52) atherosclerotic or recurrent stenosis after CEA involving the internal carotid artery (ICA), DUS surveillance was performed <or=30 days and every 6 months thereafter. High-grade stenosis (peak systolic velocity [PSV] >300 cm/s, diastolic velocity >125 cm/s, internal carotid artery stent/proximal common carotid artery ratio >4) involving the stented arterial segment prompted diagnostic angiography and repair when >75% diameter-reduction stenosis was confirmed. Criteria for >50% CAS stenosis was a PSV >150 cm/s with a PSV stent ratio >2.

RESULTS

All 114 carotid stents were patent on initial DUS imaging, including 90 (79%) with PSV <150 cm/s (94 +/- 24 cm/s), 23 (20%) with PSV >150 cm/s (183 +/- 34 cm/s), and one with high-grade, residual stenosis (PSV = 355). During subsequent surveillance, 81 CAS sites (71%) exhibited no change in stenosis severity, nine sites demonstrated stenosis regression to <50% diameter reduction, and five sites developed velocity spectra of a high-grade stenosis. Angiography confirmed >75% diameter reduction in all six CASs with DUS-detected high-grade stenosis, all patients were asymptomatic, and treatment consisted of endovascular (n = 5) or surgical (n = 1) repair. During the mean 33-month follow-up period, three patients experienced ipsilateral, reversible neurologic events at 30, 45, and 120 days after CAS; none was associated with severe stent stenosis. No stent occlusions occurred, and no patient with >50% CAS stenosis on initial or subsequent testing developed a permanent ipsilateral permanent neurologic deficit or stroke-related death.

CONCLUSION

DUS surveillance after CAS identified a 5% procedural failure rate due to the development of high-grade in-stent stenosis. Both progression and regression of stent stenosis severity was observed on serial testing, but 70% of CAS sites demonstrated velocity spectra consistent with <50% diameter reduction. The surveillance algorithm used, including reintervention for asymptomatic high-grade CAS stenosis, was associated with stent patency and the absence of disabling stroke.

Smooth muscle cell signal transduction: implications of vascular biology for vascular surgeons

Vascular smooth muscle cells exhibit varied responses after vessel injury and surgical interventions, including phenotypic switching, migration, proliferation, protein synthesis, and apoptosis. Although the source of the smooth muscle cells that accumulate in the vascular wall is controversial, possibly reflecting migration from the adventitia, from the circulating blood, or in situ differentiation, the intracellular signal transduction pathways that control these processes are being defined. Some of these pathways include the Ras-mitogen-activated protein kinase, phosphatidylinositol 3-kinase-Akt, Rho, death receptor-caspase, and nitric oxide pathways. Signal transduction pathways provide amplification, redundancy, and control points within the cell and culminate in biologic responses. We review some of the signaling pathways activated within smooth muscle cells that contribute to smooth muscle cell heterogeneity and development of pathology such as restenosis and neointimal hyperplasia.

Carotid angioplasty and stenting versus redo endarterectomy for recurrent stenosis

BACKGROUND

Carotid angioplasty and stent (CAS) is an alternative to redo carotid endarterectomy (RCEA) for recurrent carotid stenosis (RCS). The purpose of this study was to evaluate the outcomes of CAS in the treatment of RCS.

METHODS

In an 8-year period, all patients presenting for treatment of RCS were followed-up prospectively. Logistic regression analysis was performed to identify variables associated with unfavorable outcomes.

RESULTS

There were 45 CAS and 46 RCEA procedures performed in 75 patients. One patient in each group suffered a stroke. There were no deaths. The hospital length of stay was significantly shorter for CAS. Secondary recurrence was higher after RCEA (14% vs 6.1%) and failure to take beta-blockers was an independent predictor for multiple recurrences.

CONCLUSIONS

CAS is a safe and effective method to treat patients with RCS and may become the procedure of choice for this disease.

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.

Risk factors for restenosis after carotid artery angioplasty and stenting

OBJECTIVES

With carotid artery stenting (CAS) becoming an ever-increasing procedure, we sought to determine risk factors for in-stent restenosis after CAS.

METHODS

Consecutive patients undergoing CAS between January 2002 and October 2004 at a tertiary care hospital were retrospectively reviewed. Patient, filter, and stent selection were left to the discretion of the attending surgeon. High-risk patients were defined by significant comorbidities or a hostile neck (prior surgery or radiation, or both), and risk factor analysis was performed. In-stent restenosis was defined as >60%, and selective angiography was performed on patients with an in-stent restenosis >80% by duplex ultrasound imaging.

RESULTS

Reviewed were 101 patients (55 men, 46 women) who underwent 109 CAS procedures. Comorbidities were typical for patients with atherosclerosis. In addition, 38% (n = 41) of procedures were performed in patients who had prior neck surgery, of which 29% (n = 32) had previous ipsilateral carotid endarterectomy. Seventeen patients (16%) had a history of neck cancer, and all had prior neck radiation. Median follow-up was 5 months (range, 0 to 30 months). Neurologic complications included three transient ischemic attacks (2.8%) and one nondisabling stroke (0.9%). There were two myocardial infarctions (1.9%) and no periprocedural deaths (30 days), for a combined stroke, myocardial infarction, and death rate of 2.9%. Asymptomatic in-stent restenosis developed in 12 carotids (11%), five of which required endovascular intervention, with a mean of 6 months to restenosis. Univariate Cox proportional hazard regression models were used to determine risk factors for the development of restenosis. Prior stroke, transient ischemic attack, amaurosis fugax, and prior neck cancer were all significant risk factors. When these significant risk factors from univariate analysis were put into multivariate analysis, however, the only marginally significant risk factor was prior neck cancer (P = .06). Kaplan-Meier analysis revealed a cumulative freedom from in-stent restenosis at 24 months of 88% +/- 6% in patients without neck cancer compared with 27% +/- 17% (P = .02) in patients with neck cancer.

CONCLUSIONS

CAS has been shown to be safe and effective in high-risk patients, with minimal adverse events.

Endovascular Treatment of In-Stent Restenosis After Carotid Artery Stenting: Immediate and Midterm Results

PURPOSE

To evaluate the immediate and midterm outcome and analyze the debris captured after repeat endovascular intervention for the treatment of in-stent restenosis after carotid artery stenting (CAS).

METHODS

Thirty-one consecutive patients (27 men; mean age 63.7+/-13.0 years, range 53- 81) underwent repeat endovascular intervention (balloon angioplasty and provisional stenting) for the treatment of 32 in-stent restenoses following CAS.

RESULTS

Procedural success was achieved in all patients. An additional stent was implanted in 10 (31%) cases. No procedural complication was observed. Filter analysis was performed in 17 (53%) procedures; on 12 (71%), macroscopically visible material was captured. The histomorphometric analysis performed on 6 (19%) filters showed fibrin nets entrapping erythrocytes, leucocytes, platelets, and in 2 cases, fibrous hypercellular tissue fragments. At 30 days and during follow-up (mean 17+/-5 months), no deaths, transient ischemic attacks, or strokes were observed. In 1 (3.1%) patient, asymptomatic recurrence of ISR was found on Doppler ultrasonography and successfully treated with balloon angioplasty.

CONCLUSION

Repeat endovascular intervention using balloon angioplasty with provisional stenting and routine cerebral protection appears to be a feasible, safe, and clinically effective strategy for the treatment of in-stent restenosis after CAS.