Impact of head movements on morphology and flow in the internal carotid artery after carotid angioplasty and stenting versus endarterectomy

"Whiplash" cervical trauma with fracture and migration of carotid stent fragments

Background:

Angioplasty using a carotid stent is a treatment modality for carotid stenosis, with results similar to those obtained with endarterectomy, as demonstrated by important studies. The increasing use of this procedure has also led to a larger number of reports of complications, stent fractures among those. Stent fracture is a rare manifestation and hence needs further studying so that its actual prevalence can be determined, as well as its associated risk factors and proper clinical management. The current study reports the case of a patient who had previously undergone angioplasty with a carotid stent and, after an automobile accident, presented with a stent fracture and distal embolization of fragments thereof with neurological manifestation.

Case Description:

A male patient, 40 years old, presented with a history of previously stent carotid angioplasty. He had been involved in an automobile accident and suffered a stent fracture with distal fragment migration. As he was an asymptomatic patient (NIHSS 0, Rankin zero), we opted for a conservative treatment with oral anticoagulant.

Conclusion:

Angioplasty is an effective treatment for extracranial atherosclerosis and, albeit rare, stent fractures can result in the migration of fragments thereof. This occurrence should be suspected in patients who have sustained severe neck injuries due to sudden deceleration and may be associated with thromboembolism.

Anatomical Considerations for Endovascular Intervention for Extracranial Carotid Disease: A Review of the Literature and Recommended Guidelines

Patient selection for endovascular intervention in extracranial carotid disease is centered on vascular anatomy. We review anatomical considerations for non-traumatic disease and offer guidelines in patient selection and management. We conducted a systematic literature review without meta-analysis for studies involving anatomical considerations in extracranial carotid intervention for non-traumatic disease. Anatomical considerations discussed included aortic arch variants, degree of vessel stenosis, angulation, tortuosity, and anomalous origins, and atheromatous plaque morphology, composition, and location. Available literature suggests that anatomical risks of morbidity are largely secondary to increased procedural times and difficulties in intervention system delivery. We recommend the prioritization of endovascular techniques on an individual basis in cases where accessible systems and surgeon familiarity provide an acceptable likelihood of rapid access and device deployment.

Delayed cerebral infarction due to stent folding deformation following carotid artery stenting

We report a case of delayed cerebral infarction due to stent longitudinal folding deformation following carotid artery stenting using a self-expandable stent with an open-cell design. The stented segment of the left common carotid artery was divided into two different lumens by this folding deformation, and the separated lumens became restricted with in-stent thrombosis. Although no established method of managing this rare complication exists, a conservative approach was taken with administration of anticoagulant and dual antiplatelet therapy. No neurological symptoms were observed during several months of clinical follow-up after discharge.

Carotid false aneurysm after carotid stent fracture: report of a surgical solution

Stent fracture has been well documented in the Literature and in the majority of cases arises from the exposition of the stent to unfavourable stresses and biomechanical forces. We report a case of carotid false aneurysm after stent placement for post-surgery restenosis. Stent fracture is a clinical reality that sometimes should be considered prior to stent deployment and may require monitoring or treatment after occurrence.

Carotid stent fracture and restenosis management

We report an unusual case of asymptomatic accelerated right carotid artery in-stent restenosis in a patient referred for revascularization of a de novo stenosis of her left internal carotid artery.

Clinical relevance and treatment of carotid stent fractures

OBJECTIVE

To review all published reports and investigate the clinical relevance and need for treatment of carotid stent fractures.

METHODS

Electronic and hand-searching of the published literature and the Manufacturer and User Facility Device Experience (MAUDE) database.

RESULTS

Thirteen articles were published. There are 10 case reports and 3 clinical studies. There are 26 reports of fractured stents in the MAUDE database. Fifty-five cases of carotid stent fractures are reported in total. A total of 201 carotid stents were examined in the 3 studies, and the incidence of fractures was 8.9% (18/201). Fractured stents were 22 Xact, 20 Acculink, 6 Precise, 2 Exponent, 1 Nexstent, 1 Genesis, 1 Symbiot, and 2 nonspecified nitinol self-expandable stents. Twenty-seven of the treated carotid lesions were atherosclerotic, 3 restenoses after carotid endarterectomy, 2 postradiational, 1 pseudoaneurysm, and 22 lesions of unknown pathology. Calcification was reported in 15 of the 27 atherosclerotic lesions (55.5%). Time from implantation to fracture ranged from 0 days (fracture during implantation) to 37 months. In 55% of the cases, stent fracture was associated with restenosis. Six patients presented with symptoms. Treatment was reported for 32 patients: 14 patients underwent de novo stent placement, 2 balloon angioplasty, 2 carotid endarterectomy, 2 bypass graft (1 vein, 1 polytetrafluoroethylene), 1 anticoagulation, and 11 patients were followed up.

CONCLUSION

Carotid stent fractures are mainly reported in self-expandable nitinol stents. Plaque calcification may be a risk factor for stent fractures. No difference was observed between open and closed-cell design. Stent fractures were often associated with restenosis and usually were asymptomatic. The actual incidence, clinical relevance, and optimal treatment remain to be clarified from larger prospective studies designed to investigate the issue.

Carotid stent fracture: diagnosis and management

With increasing numbers of carotid stent implantations, stent fractures likely will be detected in this vessel region. The authors report two cases of stent fracture: one balloon expandable and one self expandable stent fractured and caused symptoms. CT angiography identified the stent fractures. One partial stent fracture in the internal carotid artery caused a significant restenosis. One complete stent fracture in the common carotid artery caused neurological symptoms, but no significant restenosis. Computerized tomographic angiography (CTA) findings were confirmed by conventional angiography and treated by repeated stent implantation. In a 12-month follow-up period, both patients remained further neurologically asymptomatic and there was no restenosis in duplex sonography or CTA.

Delivery and release of nitinol stent in carotid artery and their interactions: a finite element analysis

Carotid angioplasty and stenting (CAS) has emerged as an effective alternative to carotid endarterectomy, and nitinol stents are commonly used in CAS. To evaluate biomechanical properties of nitinol carotid stents and their interactions with carotid arteries, a finite element method (FEM) model was built which is composed of a stenotic carotid tissue, a segmented-design nitinol stent and a sheath. Two different stents were considered to show the influence of stent design on the stent-vessel interactions. Results show that the superelastic stents were delivered into the stenotic vessel lumen through the sheath and self-expanded in the internal and common carotid artery. The stent with shorter struts may have better clinical results and the different stent designs can cause different carotid vessel geometry changes. This FEM can provide a convenient way to test and improve biomechanical properties of existing carotid stents and give clues for new nitinol carotid stent designs.

Carotid artery dynamics after carotid angioplasty and stenting

Carotid angioplasty and stenting (CAS) has emerged as an alternative treatment for carotid artery occlusive disease. As initial results in patients with an increased surgical risk appeared promising, the popularity of CAS has increased substantially over the last years and CAS has more often been advocated as an alternative to the gold standard, carotid endarterectomy (CEA). Several controlled trials comparing CAS with CEA are currently being conducted. However, long-term results of CAS are still sparse and several issues regarding the inherent differences between treatment modalities have not yet been elucidated. Interestingly, to date, very little attention has been directed towards the mobile features of the carotid artery and the implications of stent placement on carotid artery dynamics.