Introduction: The purpose of this paper is to investigate the clinical significance of postinterventional subarachnoid hyperdensities (PSH) after endovascular mechanical thrombectomy in acute ischemic stroke.
Methods: We analysed clinical and radiological data of 113 consecutive patients who received postinterventional CT scans within 4.5 h after mechanical thrombectomy.
Results: PSH was present in 27 of 113 patients (24%). Extravasation of contrast agent was observed during intervention in only 6 of 27 cases (22%). There was consecutive haemorrhagic transformation in four patients with PSH (p = 0.209, Fisher's exact test). Preinterventional predictors for the occurrence of PSH in our series were a long interval between clinical onset and recanalization (p = 0.028), a long procedure time (p = 0.010), and a high number of recanalization attempts (p = 0.001). PSH had no significant impact on clinical outcome (modified Rankin Scale) at discharge (p = 0.419) or at 3 months (p = 0.396). There were no significant correlations between PSH and thrombectomy devices (Solitaire: p = 0.433, Trevo Pro: p = 0.124).
Conclusion: PSH after endovascular mechanical thrombectomy in acute ischemic stroke are likely to occur in complicated cases in which more than one revascularisation attempt is performed. PSH per se do not appear to be associated with an impaired clinical outcome or an elevated risk for consecutive haemorrhage.