Formation of an aneurysm at the anastomosis site is a rare complication of superficial temporal artery-middle cerebral artery (STA-MCA) bypass for moyamoya disease (MMD). All 5 previously reported cases were treated with craniotomy, and no case of endovascular treatment has been reported to date. Here, we report a case in which endovascular treatment was performed for an anastomotic aneurysm that developed after STA-MCA bypass surgery for MMD. A 46-year-old woman with no relevant medical history developed a cerebral hemorrhage and was diagnosed with MMD. Bilateral STA-MCA bypass was performed to prevent recurrence of bleeding, and a de novo aneurysm was found at the right anastomosis site 1 year after the surgery. After a 2-year follow-up period, the size of the aneurysm and the diameter of the STA increased; therefore, treatment was initiated. Endovascular treatment was performed using the double-catheter technique. After coil embolization, the aneurysm was no longer visible, and no complications were observed. Anastomotic aneurysms after STA-MCA bypass can be safely and effectively treated with endovascular therapy.
Ikezawa et al. (Wed,) studied this question.