Effects of burr-hole surgery on MRI cerebral perfusion and stroke risk in adults with moyamoya angiopathy

Purpose. Several surgical techniques have been proposed in moyamoya angiopathy (MMA) to reduce stroke risk; nevertheless, no one has clearly demonstrated its superiority. Burr-hole surgery allows the revascularization of large frontal areas and thus is increasingly used, but it has not been systematically evaluated in adults. We assessed the effect of burr-hole surgery as the only revascularization technique on MRI brain perfusion and stroke recurrence in adult patients with MMA. Methods. Retrospective study of consecutive adults patients with MMA and predominant frontal hypoperfusion treated by burr-hole surgery in a tertiary hospital. Parenchymal hypoperfusion rate on perfusion-weighted imaging (PWI) was compared using TMax before and 6 months after surgery. Perioperative complications and long-term risk of stroke/transient ischemic attack (TIA) were reviewed. Results. A total of 19 patients (11 women, mean age at surgery ± SD 42.4 ± 8.6 years) were included. A median of 7 (4–9) burr holes/hemisphere were performed on 34 hemispheres. Perioperative cerebral infarction occurred in 3 (15.9%) patients on 3 hemispheres (8.8%/hemisphere). The volume of slightly (Tmax ˃ 4 s) and severely (Tmax ˃ 6 s) hypoperfused parenchyma significantly decreased after surgery (p = 0.003 and p = 0.008, respectively). After a median follow-up of 72 (IQR 24.6) months, 4 strokes occurred in 3 patients (11.7%/hemisphere). The 2-year survival probability free of stroke/TIA was 85%. Conclusion. In adults with MMA and predominant frontal hypoperfusion, burr-hole surgery as the sole revascularization technique improved brain perfusion as measured with Tmax. Moreover the long-term risk of ischemic events and the rate of complications seemed similar to other techniques.