Short- and long-term outcomes of moyamoya patients post-revascularization

OBJECTIVE The post-bypass stroke risk factors and long-term outcomes of moyamoya patients are not well document-ed. Therefore, the authors studied 30-day stroke risks and patients' long-term physical, functional, and social well-being.METHODS This was a single-institution combined moyamoya disease (MMD) database interrogation and question-naire study. From 1991 to 2014, 1250 revascularization procedures (1118 direct bypasses, 132 indirect bypasses) were performed in 769 patients. Completed questionnaires were received from and available for analysis on 391 patients, and 6-month follow-up data were available for 96.4% (741/769) of the patients.RESULTS The patients consisted of 548 females and 221 males, with a mean age of 32 years (range 1-69 years). Three hundred fifty-eight bypasses were performed in 205 pediatric patients (73% direct bypasses), and 892 revas- cularizations were performed in 564 adults (96% direct bypasses). Fifty-two patients (6.8%) developed major strokes with a worsening modified Rankin Scale (mRS) score within 30 days postoperatively. The 30-day major stroke risk was 5.3% (41/769) and 2.6% (12/467) after the first and second bypasses, respectively. Logistic regression analysis revealed that older age, modified MRI (mMRI) score, and hemodynamic reserve (HDR) score are clearly associated with higher postoperative stroke risks. Over a mean follow-up of 7.3 years (range 0.5-26 years), the long-term stroke risk among 741 patients was 0.6% per patient-year; 75% of these patients had excellent outcomes (mRS score 0-1). The long-term out-come questionnaire study showed that 84% (234/277) of patients reported resolution or improvement in their preopera-tive headache, 83% (325/391) remained employed or in school, and 87% (303/348) were self-caring.CONCLUSIONS In this large, single-center surgical series, most of the adult and pediatric patients had direct revascu-larization, with a 4.2% per-bypass-procedure (6.8% per patient) 30-day major stroke risk and a 0.6% per-patient-year long-term stroke risk. The authors identified various risk factors that are highly correlated with postoperative morbidity (age, mMRI score, and HDR score) and are involved in ongoing work to develop the predictive modeling for future patient selection and treatment.

Automated summary

The study found that the 30-day stroke risk after bypass surgery in moyamoya patients was 4.2% per procedure and the long-term stroke risk was 0.6% per patient-year. The study also identified age, MRI score, and hemodynamic reserve score as risk factors for postoperative morbidity. These findings can contribute to the development of predictive models for patient selection and treatment.