Efficacy of STA-MCA bypass surgery in moyamoya angiopathy: long-term follow-up of the Caucasian Krupp Hospital cohort with 81 procedures

Despite the consensus on the efficacy of revascularizing surgery in moyamoya angiopathy (MA) in Asia, the indication in Caucasian moyamoya patients is controversially discussed. The efficacy of revascularizing surgery in adult European patients with MA should be clarified. This study retrospectively analyzed the rate of further strokes and hemorrhages as well as MRI and Duplex ultrasound features during long-term follow up after STA-MCA bypass. Eighty-one STA-MCA bypass procedures in 54 patients with MA operated in one single German institution were analyzed. All 54 patients (100%) were Caucasians. After two diffusion restricted spots in MRI perioperatively (2.5%) and short-lasting symptoms directly after surgery, no patient experienced further new symptoms related to stroke or hemorrhages nor no new gliotic scars or microbleeds on MRI for 38.2 months. Duplex ultrasound 3 months after surgery documented bypass patency in 100% and sonographic sign for good relevance of the bypass in 96.2%. In addition, the diameter of the donor vessel had increased in 89.9% as an indicator for the relevance of the bypass. Semi-quantitative analysis of perfusion changes in the operated hemispheres demonstrated an increase in perfusion in the MCA territory in 56 of 74 (75.7%) hemispheres 36.7 months after surgery. In MRA images, a reduction of typical moyamoya collaterals was found in 65 of 79 hemispheres (82.3%) after a mean of 37.2 months. Direct STA-MCA bypass is an effective therapy in Caucasian patients with hemodynamically compromised MA.