椎骨脳底動脈系頭蓋内動脈解離の全国調査（最終報告）第2報─出血発症─

To investigate the current status of management and outcomes in patients with non-traumatic hemorrhage after intracranial vertebrobasilar artery dissection (VAD), we conducted a nationwide study over a period of 1 year (2011) in Japan.<br>Of 632 patients with VAD, 193 patients were enrolled for the onset of hemorrhage. The following patient characteristics were recorded: age, gender, location of arterial dissection, radiographic findings, presence or absence of rebleeding, treatment, follow-up periods, and mid-term outcomes. The outcomes were evaluated using modified Rankin scale (mRS), and a good outcome was defined as an mRS score of 0-2.<br>Regarding disease severity, Hunt and Kosnik (HK) grade-4 or grade-5 disease was observed in 48.2% of the patients. Hydrocephalus was detected in 43.6% of the patients. Rebleeding was observed in 21.5% and usually occurred within 24 hours after the onset of hemorrhage. For the prevention of rebleeding, surgical treatment, including 33 craniotomies (group C) and 127 endovascular surgeries (group E), was administered to 160 patients (82.9%). Conservative or medical treatment was administered to the remaining 33 patients (group M). Trapping was the most frequent procedure performed for the patients in groups C and E. Bypass surgery was performed in 11 patients (6.9%). Postoperative intracranial complications occurred in 23.8%, and the most common complication was ischemic events. In group C, a higher incidence of ischemic complication was observed in patients treated with trapping than in those treated by proximal occlusion. However, in group E, the incidence of ischemic events did not differ between patients treated by trapping and those treated by proximal occlusion.<br>At the final follow-up, 56.5% of the patients achieved a good final outcome (mRS score, 0-2) and 25.9% of the patients died during the follow-up. After the treatment, 54.5% of the patients in group C, 60.6% in group E, and 42.4% in the medical treatment group showed good outcomes.<br>Advanced age, hydrocephalus, rebleeding, posterior inferior cerebellar artery dissection, and a high HK grade were associated with poor outcomes.<br>Endovascular surgery has been a highly common treatment option during last 2 decades. The outcomes and prognostic factors of hemorrhage in the VAD patients were similar to those previously reported.