COLLATERAL CIRCULATION AND OUTCOME AFTER BASILAR ARTERY THROMBOLYSIS

BACKGROUND AND PURPOSE: This study was undertaken to examine the relat ionship between collateral flow and outcome after local intraarterial thrombolytic treatment for basilar artery thrombosis. METHODS: Twenty- four patients with symptomatic basilar thrombosis were treated with in traarterial urokinase. Angiograms at the time of treatment were analyz ed to characterize collateral flow. The number of posterior communicat ing arteries (PCoAs) and the degree of collateral filling of the basil ar artery were then compared with symptom duration before treatment, w ith Glasgow Coma Scale (GCS) score at the time of treatment, with 90-d ay modified Rankin score, and with 90-day survival status. RESULTS: Of the 20 patients who had carotid artery injections at the time of the thrombolytic procedure, two had no PCoA, eight had one PCoA, and 10 ha d two PCoAs. Nine had no collateral opacification of the basilar arter y, six had collateral opacification of the distal basilar artery, and five had collateral opacification of the distal and proximal basilar a rtery. Ninety-day survival was 38%; 25% of patients had good neurologi c outcomes. No correlation was found between the number of PCoAs and s ymptom duration, pretreatment GCS score, survival, or neurologic outco me. Duration of symptoms before treatment was longer in patients with collateral flow to the basilar artery. Basilar artery collateral Bow d id not correlate with survival, but it did correlate with neurologic o utcome for the 12 patients with middle or distal basilar artery thromb us in whom collateral flow to the basilar artery was assessed (83% wit h collateral flow had good neurologic outcomes, but only 17% without c ollateral flow had good outcomes). All six patients with proximal basi lar artery thrombus in whom collateral Bow was assessed died, independ ent of the collateral flow observed. CONCLUSION: In symptomatic acute basilar artery thrombosis, neurologic outcome was better after intraar terial thrombolysis in patients who had collateral filling of the basi lar artery, except in cases of proximal basilar thrombosis. Patients w ith collateral filling of the basilar artery also tolerated longer sym ptom duration.