Long-term outcomes of moyamoya disease following indirect revascularization in middle adulthood: A prospective, quantitative study

BACKGROUND/PURPOSE:Our previous study demonstrated that indirect revascularization is effective in the treatment of adult moyamoya patients. This prospective study aims to evaluate the long-term effectiveness of indirect revascularization in moyamoya patients in middle adulthood. METHODS:From January 2013 to June 2019, moyamoya patients more than 40 years of age underwent indirect revascularizations were studied. The hypoperfusion area of brains was revascularized. The cerebral angiography and time-to-peak (TTP) scoring (ranged 0-14) of the magnetic resonance perfusion study were used to evaluate the revascularization effect. RESULTS:During the study period, 50 consecutive adult moyamoya patients underwent indirect revascularization. Seventeen patients (27 cerebral hemispheres) more than 40 years of age were included. The mean age was 47.9 ± 6.4 years, and 13 patients were female. The pre-operative Suzuki stages were I, II, III, IV, V, and VI in 1, 1, 9, 13, 0, and 3 hemispheres, respectively. After a mean follow-up period of 52.5 ± 20.6 months, all patients had improvement or stabilization of their clinical conditions. Available post-operative angiography demonstrated Matsushima grading A in 18 of 20 hemispheres. The mean TTP score of all 27 hemispheres improved from 5.0 ± 3.3 pre-operatively to 12.0 ± 2.1 after surgery (p < 0.001). The post-operative mean TTP score of the 7 hemispheres without angiographic follow-up was 10.4 ± 1.8. One patient had persistent mild motor weakness after 56-month follow-up. Transient complications with full recovery occurred in 3 patients. CONCLUSION:Indirect revascularization is a safe method with satisfactory long-term results in moyamoya patient in middle adulthood.