Objective: Symptomatic "non-acutely" occluded internal carotid artery (NAOICA) results in stroke, cognitive impairment, and hemicerebral atrophy through cerebral hypoperfusion and artery-to-artery embolism. Atherosclerosis is the main cause of NAOICA. Conventional one-stage endovascular recanalization showed effectiveness but was plagued by many challenges. This retrospective analysis reports the technical feasibility and outcomes of the staged endovascular recanalization in patients with NAOICA.
Methods: Eight consecutive patients with atherosclerotic NAOICA and ipsilateral ischemic stroke within 3 months between January 2019 and March 2022 were retrospectively reviewed. The patients (all males, with a mean age of 64.6 years) underwent staged endovascular recanalization 13 to 56 days after documented occlusion by imaging techniques (mean 28.8 days); the mean follow-up period was 20 months (range: 6-28). The approach of the staged intervention was as follows. In the first stage, the occluded ICA was successfully recanalized using the simple small balloon dilation technique. In the second stage, angioplasty with a stent implant was performed with >50% residual stenosis in the initial segment or ≥70% residual stenosis in the C2-C5 segment. The technical success rate, the incidence of clinical adverse events (any stroke, death, cerebral hyperperfusion), and long-term in-stent stenosis (ISR) and reocclusion rates were evaluated.
Results: Technical success was achieved in seven patients, with early reocclusion occurring in one patient after the first-stage intervention. There were no adverse events observed within 30 days (0%), and long-term reocclusion and long-term ISR rates were both 14% (1/7). However, all patients developed iatrogenic arterial dissections during the first stage, indicating the challenge of reaching the true lumen through the occlusion site without damaging the intima. Based on the National Heart, Lung and Blood Institute (NHLBI) classification, there were two type A, four type B, three type C, and two type D dissections. The mean time interval between the two stages was 46.1 days (21-152 days). All type A and B dissections resolved spontaneously after ≥3 weeks of dual antiplatelet therapy, whereas most type C and all type D dissections did not heal spontaneously before the second stage. Also, one type C dissection led to reocclusion. This observation suggested that dissections without flow limit and persistent vessel staining or extravasation could be clinically observed, while severe dissections (characterized as type C or greater) required prompt stenting rather than conservative treatment. Performing high-resolution MRI preoperatively to exclude fresh thrombus in the occluded vessel segment is indispensable in selecting appropriate candidates for endovascular recanalization. This could avoid downstream embolism during the interventional procedure.
Conclusions: This retrospective study found that staged endovascular recanalization for symptomatic atherosclerotic NAOICA may be feasible with an acceptable technical success rate and a low complication rate in the selected candidates.
Keywords: Subacute occlusion; chronic occlusion; iatrogenic dissection; internal carotid artery; recanalization; staged endovascular treatment.