Ischemic stroke is the fourth leading cause of disability and mortality in the United States. The overall risk of emboli detachment from a chronically occluded internal carotid artery (COICA) is around 7% per year. Despite receiving the best available medical therapy, about 6% to 24% of these patients will subsequently suffer transient or permanent ischemic complications annually. This has been theoretically attributed to a cerebrovascular hemodynamic impairment.
The management of chronic or subacute internal carotid artery (ICA) occlusions has been challenging clinically. Carotid endarterectomy and superficial temporal artery to middle cerebral artery bypass have been studied in high risk stroke patients with results showing no benefits in symptomatic COICA patients. Consequently, some centers have employed angioplasty and stenting for the management of these challenging lesions. The main concern with the endovascular treatment of COICA patients is the significant risk of perioperative complications such as distal embolization, vessel perforation, pseudoaneurysm formation, vessel dissection, fistula formation, and hyperperfusion syndrome. In this report, we propose for the first time a COICA classification, which could offer the interventionalist a guide of the technical feasibility and safety of endovascular recanalization of symptomatic COICA. We will assess the success of this classification in predicting endovascular recanalization of symptomatic COICA in a single -institution pilot study.
Classification of Carotid Artery Occlusion:
The radiographic imaging of 100 consecutive subjects with a diagnosis of chronically occluded cervical ICA (COICA) in the interval of 2009 - 2017 were evaluated at the University of Iowa Hospitals and Clinics were analyzed. Reviewers used morphology and location of occlusion, in addition to presence or absence of reconstitution of distal cervical ICA evident of MRA, CTA, and /or DSA to stratify this cohort of subjects into 4 categories. The rational for this classification was to evaluate whether it would potentially predict which COICA subjects could be viable candidates for the revascularization procedure using endovascular techniques. Of course this classification would need to be validated in larger cohort of patients.
Type A (figure 1): The occlusion of the cervical ICA is tapered with proximal ICA lumen patent. In addition, the cavernous and/or petrous segment is reconstituted by either collaterals from the ECA and/or retrograde filling from the supraclinoid segment. This type is thought to be the most technically feasible to revascularize using endovascular techniques.
Type B (figure 1): The occlusion of the cervical ICA is not tapered but there is a stump where the proximal portion of the cervical ICA lumen is patent. In addition, the cavernous and/or petrous segment is reconstituted by either collaterals from the ECA and/or retrograde filling from the supraclinoid segment. This type is thought to be the second best after type A to technically revascularize using endovascular techniques.
Type C (Figure 1): The occlusion of the cervical ICA is at the common carotid artery bifurcation (the cervical ICA appears completely amputated at the bifurcation), and there is no ICA lumen observed. The common carotid artery continues as ECA. However, the cavernous and/or petrous segment is reconstituted by either collaterals from the ECA and/or retrograde filling from the supraclinoid segment. This type is thought to be technically difficult to revascularize using endovascular techniques.
Type D (figure 1): is the same as Type C except that there is no reconstitution of the cavernous and/or petrous segment. This type is thought to be the most difficult type to revascularize using endovascular techniques. This type should only considered for revascularization in acute ischemic stroke because this type could be encountered with tandem lesions during the acute phase.
To test whether our proposed classification could predict the technical feasibility and safety of endovascular revascularization of symptomatic COICA, we will perform a pilot study.
- Angioplasty and stenting of occluded cervical ICA Procedure
Intervention Desc: The procedure is performed under monitored anesthetic care. We will perform a thorough and complete six-vessel diagnostic angiogram to completely characterize the occlusion and presence of collaterals. A distal protection device is used unless technically can't be delivered beyond the occlusion or when the occlusion extends beyond the petrous segment of the internal carotid artery. Balloon angioplasty is performed followed by deployment of covered stents to jail the clot/organized thrombus. The carotid reconstruction is performed from the distal to the proximal segment with coronary stents that are telescoped until normal flow is encounter. The Blood pressure is managed rigorously during and after the procedure to minimize the chances of reperfusion hemorrhage. ARM 1: Kind: Experimental Label: Symptomayic chronically occluded cervical ICA
|Type||Measure||Time Frame||Safety Issue|
|Primary||brain hemorrhage||30 days post procedure|
|Secondary||Transient ischemic stroke and stroke||3 months post procedure|
|Secondary||modified Rankin Score (mRS)||3 months post procedure|
- University of Iowa Lead