Complex interventional treatment in a patient with atrial fibrillation and stroke caused by large carotid artery thrombus: a case report

The treatment option for acute ischaemic stroke depends on the duration of symptoms, the dynamics of any neurological condition changes, the aetiology of the stroke, as well as the results of angiographic and neuroimaging tests. As per current recommendations, initial considerations include reperfusion methods based on intravenous thrombolysis or, in selected cases, intra-arterial thrombolysis. Whether greater benefits are obtained from applying mechanical thrombectomy as the only form of treatment or in combination with pharmacological thrombolysis is currently the subject of research. According to updated guidelines, thrombectomy may be performed in patients with cerebral stroke induced by acute critical narrowing or occlusion of intracranial arteries, which neither qualify for, nor benefit from, intravenous thrombolysis [1]. Cerebral stroke due to acute cerebral and/or carotid artery occlusion is characterised by severe progression and poor outcome [2]. In such cases, complete arterial recanalisation after intravenous rt-PA administration is observed in as few as 10–11% of patients [3-6]. In the “carotid T-occlusion” (thrombolytic occlusion from the proximal ICA section to the ACA and MCA), the prognosis is uncertain, even if recanalisation is performed within a few hours. Brekenfeld et al. [7] report a favourable outcome in only 17% of patients in the 3rd month post-stroke (mRankin ≤ 2) despite observed ICA, MCA and ACA recanalisation in 63%, 17% and 33% of cases, respectively [7].

The extent of cerebral ischemia depends on the compensatory capabilities of collateral circulation in the Circle of Willis or leptomeningeal anastomosis, and on the capability to restore brain circulation within the therapeutic window. Endovascular interventions may be more effective than intravenous and/or intra-arterial thrombolysis [8]. Although there is no doubt that, when applied within a short time from the onset of the disease, endovascular approaches result in a more favourable prognosis, these approaches may still be implemented during the extended therapeutic window, i.e., from 8 to 12 h from the onset of the stroke [9-11]. When considering that cerebral stroke patients are often admitted to hospital beyond the thrombolytic therapeutic window, endovascular therapy is a favourable alternative for the majority of occluded arteries.

Emergency surgical embolectomy in patients with carotid artery occlusion in the acute stroke phase is rarely considered. Yet, it is worth noting that 10–20% of all strokes within the anterior part of the Circle of Willis are associated with ICA pathology [12]. In such cases, the occluded downstream intracranial vessels (e.g., MCA) may be recanalised by systemic or local thrombolysis. Unblocking intracranial vessels using a thrombolytic drug despite residual occlusion of the ICA may only result in temporary reperfusion. Achieving permanent improvement of cerebral artery patency depends on the condition of the carotid artery that feeds it. This is true especially in cases with T-occlusions, which is exemplified in the present patient. The dynamics of intravascular lesions in our patient may be tracked based on radiographic examinations. Within 2 h of the angio-CT examination upon admission to hospital and the performed procedure, an expansion of the occlusion from the level of the ICA cavernous section to the ACA and MCA occurred. Only a comprehensive reperfusion strategy, such as a CCA embolectomy with ICA thrombectomy and local thrombolysis, provided an opportunity for quick restoration of vessel patency and for preventing further progression of cerebral ischaemia, such as found here. The decision to select a mixed revascularisation treatment was based on the understanding that the effectiveness of thrombolytic treatment in the case of “old” fibrous embolic lesions is limited and that their size significantly limits the possibility of complete embolism removal. Observations to date with the use of carotid artery embolectomy in treating strokes are scarce, and their results are variable. The interpretation of those results is all the more difficult as reports involve both patients with cardiogenic carotid artery emboli and patients with an occlusion of the ICA resulting from atherosclerotic thrombosis with intracranial progression [12-14]. However, some reports describe the positive effect of thrombectomy and surgical embolectomy in patients previously not subjected to thrombolytic therapy, or where thrombolytic therapy was insufficient [12,15,16].

Perhaps because of diagnostic difficulties and the necessary time window, descriptions of surgical embolectomy of the ICA and its branches are still rare. Touho et al. [4] presented results where the CCA was effectively unblocked with the aid of surgical embolectomy in four patients, which constituted 66.7% of performed interventions. Murata et al. [17] describes three cases of effective surgical embolectomy of the common and internal carotid arteries. Finally, Inoue et al. [18] reveals positive outcomes from embolectomy following a retrospective analysis of 23 patients with occlusion of the ICA and/or its branches. There is no consensus at present on the possibility and efficacy of endovascular treatment in patients with acute ischaemic stroke due to atherosclerotic occlusion of the extracranial ICA. This type of stroke, caused by acute occlusion of the ICA, is usually associated with significant morbidity and mortality. In the study published by Papanagiotou et al. [19], the authors demonstrated a high technical success rate of carotid artery stenting in acute extracranial ICA occlusion. In their paper, the clinical outcomes of the extracranial revascularisation were evaluated in a group of 22 patients; in 18 patients, an additional intracranial occlusion of ICA or MCA was found and treated with endovascular methods. Successful recanalisation of extracranial ICA was achieved in 95% of cases and intracranial vessel recanalisation was obtained in 61% of cases with an overall recanalisation rate of 63%. During follow-up, nine of 22 patients (41%) had a modified Rankin Score of ≤2 at 90 days with observed mortality rate in the whole cohort of 13.6% at 90 days [19].

In the case described here, owing to the dynamics of clinical and radiological lesions, and the presence of a multi-level acute occlusion of both the CCA and ICA and its branches, a decision was made to proceed surgically, with subsequent intra-arterial rt-PA. The decision to undertake treatment resulted from the nature of the above-mentioned lesions. Very often, cardiogenic embolisms have the form of “hard” fibrous lesions, which considerably impacts the effectiveness of thrombolytic treatment. The effect of intravenous thrombolysis depends on the size of the embolism, while the opportunity for recanalisation of an artery with a cardiogenic embolism with a size of > 8 mm2 is slight [20]. However, because of the size and nature of the embolism (hard fibrous masses), the application of percutaneous mechanical thrombectomy was unlikely to succeed in complete removal of the embolism from the area of the CCA. Moreover, it could lead to fragmentation of the embolic material from manipulation of endovascular catheters with further transmission to smaller arteries and further cerebral ischaemia. The performance of a surgical procedure under fluoroscopic control, simultaneous application of intracranial treatment in the form of thrombectomy, and intra-arterial thrombolytic treatment made it possible to obtain quick recanalisation of treated vessels beyond the level of the primary closure.