Delayed improvement in carotid artery diameter after carotid angioplasty

Staged Carotid Artery Stenting for Prevention of Hyperperfusion-Induced Intracerebral Hemorrhage in Patients with Very High-Grade Carotid Stenosis and Poor Collateral Compensation

OBJECTIVE

Hyperperfusion-induced intracerebral hemorrhage (HICH) is a relatively rare but potentially devastating event after carotid artery stenting (CAS). Staged angioplasty (SAP), a 2-stage form of CAS, has been shown to be effective for preventing cerebral hyperperfusion syndrome. The aim of our retrospective single-center study was to investigate the safety and efficacy of SAP to prevent HICH in patients with very severe carotid stenosis (90%-99%) and poor collateral compensation.

METHODS

Between November 2011 and August 2018, 153 patients presented with severe symptomatic carotid artery stenosis ≥90%; 96 were scheduled to undergo regular CAS, and 57 were scheduled for SAP. High risk of HICH were identified based on severe stenosis degree (90%-99%) and poor collateral compensation, which were determined using digital subtraction angiography and qualitative computed tomography perfusion. Patients' clinical data, procedural details, and occurrence of HICH were compared between regular CAS and SAP groups.

RESULTS

Of 57 patients scheduled for SAP, 3 were switched to regular CAS because of intraoperative dissection. The median interval between stages I and II was 8 days (IQR: 4-20 days). One patient who was switched to regular CAS experienced HICH. HICH occurred in 1 patient (1.75%; 1/57) in the SAP group and 12 patients (12.5%; 12/96) in the regular CAS group (odds ratio 0.117, 95% confidence interval 0.014-0.990, P = 0.049). Multivariate analysis showed that SAP was negatively related to cerebral hyperperfusion syndrome (odds ratio 0.117; 95% confidence interval 0.014-0.990; P = 0.049).

CONCLUSIONS

SAP is an effective treatment for avoiding HICH in patients with carotid preocclusive stenosis (90%-99%) and poor collateral compensation.

Staged carotid artery stenting in patients with severe carotid stenosis: Multicenter experience

Cerebral hyperperfusion syndrome (CHS) is serious complication after carotid artery stenting (CAS) caused by decreased cerebral vasoreactivity (CVR) due to long standing hypoperfusion of the brain. We hypothesized that partial dilatation of carotid stenosis would allow the recovery of CVR, and prevent CHS when definitive angioplasty with stent is performed afterward. In this study, we aimed to evaluate the safety and efficacy of staged CAS in patients with severe carotid artery stenosis with evident hemodynamic compromise in regard to preventing hyperperfusion syndrome. From January 2005 to February 2016, 53 patients with 55 severe carotid artery stenosis lesions showing decreased CVR and/or cerebral basal flow at the perfusion studies underwent staged CAS in three institutes. The procedure consisted of initial partial balloon angioplasty (BA), recovery period, and delayed definitive stenting (DS). We analyzed immediate results, complications, recoil and CHS related to staged CAS. We experienced no symptomatic manifestation of CHS except self-limited headache after the procedures. The median of intervals between BA and DS stages were 10 days. There was no case of severe recoil during the interval between BA and DS stage. Where perfusion imaging data was available, hyperperfusion was present in three and one patients after BA and DS stage, respectively, with no clinical symptom of CHS. In conclusion, staged CAS was feasible in patients with severe carotid artery stenosis and hemodynamic compromise, without inducing severe complication of CHS such as intracranial hemorrhage.

A clinical survey of vascular stents

As a result of the many different potential locations to be treated, it is still difficult to evaluate the indications for efficacy and safety of non-coronary percutaneous transluminal angioplasty (PTA) and stenting versus surgical methods, such as endarterectomy or bypass grafts. This paper reviews pertinent data published in the last 5-10 years and gives an overview of the main peripheral minimally invasive vascular interventional fields.

Prevention and treatment of thromboembolic and ischemic complications associated with endovascular procedures: Part II--Clinical aspects and recommendations

We reviewed the incidence, risk factors, and clinical features of thromboembolic and ischemic events associated with diagnostic cerebral angiography, endovascular treatment of aneurysms using coils or balloons, angioplasty and stent placement to treat extracranial carotid artery stenosis, and embolization of arteriovenous malformations using glue or other embolic agents. We performed a cumulative analysis to determine the frequency and characteristics of these events and a subset analysis (whenever possible) to determine the benefits of various strategies for complication avoidance. Of the 1,547 patients who underwent Guglielmi detachable coil treatment, thromboembolic events were observed for 127 (8.2%), consisting of asymptomatic events for 12 patients, transient ischemic attacks for 29, and strokes for 86. The outcomes for the 86 patients with strokes were categorized as full recovery for 15, good recovery for 27, partial recovery for 19, no recovery for 11, death for 12, and undetermined outcome for 2. Of the 834 patients who underwent carotid angioplasty and stent placement, thromboembolic events were observed for 73 (8.8%), consisting of transient ischemic attacks for 26 patients and strokes for 47. The outcomes for the patients with strokes were categorized as full recovery for 20, good recovery for 15, partial recovery for 6, no recovery for 2, and death for 4. High rates of thromboembolic events were also observed with balloon occlusion of aneurysms (11%) or parent arteries (19%) and carotid angioplasty alone (5.9%). Arteriovenous malformation embolization was associated with an ischemic event/procedure rate of 9.4%. High rates of thromboembolic and ischemic complications, with subsequent morbidity and death, are associated with most endovascular procedures. Further research and the formulation of standard preventive guidelines may help to reduce these risks and improve the overall success of these procedures.

Stent placement versus percutaneous transluminal angioplasty of human carotid arteries in cadavers in situ: distal embolization and findings at intravascular US, MR imaging and histopathologic analysis

PURPOSE

To compare endovascular stent placement with percutaneous transluminal angioplasty (PTA) of carotid arteries with respect to distal embolization and findings at intravascular ultrasonography (US), magnetic resonance (MR) imaging, and histopathologic analysis.

MATERIALS AND METHODS

PTA was performed in situ in one carotid artery, and stent placement was performed in the other, in ten cadavers (age range, 57-82 years; mean age, 68 years) with severe atherosclerosis by using fluoroscopic and intravascular US guidance. The carotid artery was connected to a pressurized tubing system in which a pulsatile pump circulated water. The effluent water was collected during the interventions, and after filtration and staining, the embolic material was analyzed histologically. After the interventions, the arteries were excised and 1.5-T spin-echo MR imaging was performed.

RESULTS

No difference in severity of distal embolization during stent placement versus during PTA was found. The embolic particles were composed mainly of intimal strips and cellular constituents of the atherosclerotic plaques. MR imaging accurately depicted postinterventional changes, and the findings correlated closely with those of intravascular US and histopathologic analysis.

CONCLUSION

Although stent placement and PTA were associated with equal distal embolization, the smooth surface and fully patent arterial lumen depicted at intravascular US and MR imaging postinterventionally may indicate that stent placement is preferable to PTA.

Percutaneous transluminal angioplasty and stent placement for recurrent carotid artery stenosis

OBJECT

Treatment consisting of percutaneous transluminal angioplasty (PTA) and stent placement has recently been proposed as an alternative to surgical reexploration in patients with recurrent carotid artery stenosis following endarterectomy. The authors retrospectively reviewed their experience after performing 25 procedures in 21 patients to assess the safety and efficacy of PTA with or without stent placement for carotid artery restenosis.

METHODS

The mean interval between endarterectomy and the endovascular procedures was 57 months (range 8-220 months). Seven arteries in five patients were treated by PTA alone (including bilateral procedures in one patient and repeated angioplasty in the same vessel in another). Early suboptimum results and recurrent stenosis in some of these initial cases prompted the authors to combine PTA with stent placement in the treatment of 18 arteries over the past 3 years. No major periprocedural deficits (neurological or cardiac complications) or death occurred. There was one periprocedural transient neurological event, and in one patient a pseudoaneurysm of the femoral artery (at the access site) required surgical repair. In the 16 patients who each underwent at least 6 months of follow-up review, no neurological events ipsilateral to the treated artery had occurred after a mean follow-up period of 27 months (range 6-57 months). Three of five patients who underwent PTA alone developed significant (>50%) asymptomatic restenoses that required repeated angioplasty in one and PTA with stent placement in two patients. Significant restenosis (55%) was observed in only one of the vessels treated by combined angioplasty and stent placement.

CONCLUSIONS

Endovascular PTA and stenting of recurrent carotid artery stenosis is both technically feasible and safe and has a satisfactory midterm patency. This procedure can be considered a viable alternative to surgical reexploration in patients with recurrent carotid artery stenosis.

Angioplasty and stenting in the carotid and vertebral arteries

Carotid and vertebral artery percutaneous transluminal angioplasty and stenting are new, experimental techniques. Their potential uses are discussed and the results and complications reported to date are reviewed.