Japanese Registry Studies Endovascular Therapy for Asymptomatic Unruptured Intracranial Aneurysms

July 30, 2013—Tomoyoshi Shigematsu, MD, et al, on behalf of the JR-NET (Japanese Registry of Neuroendovascular Therapy) investigators, have conducted an analysis of the short-term outcomes of endovascular therapy (EVT) in treating asymptomatic unruptured intracranial aneurysms (UIAs). In Japan, the current status and outcomes of neuroendovascular therapy are determined by national registration studies, JR-NET and JR-NET2. The JR-NET findings on UIA are available online ahead of print in Stroke.

The investigators concluded that the radiographic results of EVT for asymptomatic UIAs in Japan were acceptable, with low mortality and morbidity rates.

As summarized in Stroke, the investigators extracted periprocedural information regarding EVT for 4,767 asymptomatic UIAs from 31,968 registered procedural records of all EVTs in the JR-NET and JR-NET2 databases. They assessed the features of the aneurysms and procedures, immediate radiographic findings, procedure-related complications, and clinical outcomes 30 days after the procedures.

The investigators reported in Stroke that they located 80% of UIAs in the anterior circulation, and the most frequent type were paraclinoid. The diameter of 2.5%, 32.9%, 51.9%, 12%, and 0.7% of the UIAs were < 3 mm, 3–4 mm, 5–9 mm, 10–19 mm, and > 20 mm, respectively. EVT failed in only 2.1% of cases. Adjunctive techniques were applied in 54.8% of procedures. Pre- and postprocedural antiplatelet agents were prescribed in 85.6% and 84% of the procedures, respectively. The immediate radiographic outcomes of 57.7%, 31.9%, and 10% of the UIAs comprised complete occlusion, residual necks, and residual aneurysms, respectively. Complications that were associated with 9.1% of procedures comprised 2% hemorrhagic incidents and 4.6% ischemic incidents, and the 30-day morbidity and mortality rates were 2.12% and 0.31%.