The feasibility of performing multiple burr hole surgery in pediatric moyamoya patients as a response to failed mEDAS.

Objective To investigate the feasibility and clinical effectiveness of performing multiple burr hole surgery in pediatric moyamoya patients as a response to failed modified encephaloduroarteriosynangiosis (mEDAS). Methods From January 2014 to May 2018, multiple burr hole surgery (MBS) was conducted on 16 hemispheres in 12 patients as a secondary treatment following mEDAS. The male-to-female ratio was 1:2 and the average age at the time of mEDAS was 6 years old. The average patient age was 9 ± 3 years olds (range 7-17) at the time of MBS which occurred an average of 46 months after mEDAS. An average of 10 ± 1 holes (range 8-13) were made. Time-to-peak (TTP) magnetic resonance images (MRI) were taken along 20 axial cuts. Of these cuts, two consecutive cuts on the lateral ventricle were selected to calculate the average value of the region of interest (ROI). The value of the cerebellum was subtracted from the average value of two consecutive cuts. The ROI value was analyzed using a paired t test by SPSS 20 (SPSS Inc., Chicago, IL, USA). Results All 16 cases presented improvement of clinical symptoms as determined by ROI analysis of the TTP MRI images. The average ROI value was 5.03 ± 6.36 before MBS and - 15.54 ± 9.42 after MBS. The average change in the ROI value was - 20.58 ± 12.59. The ROI value decreased in all cases after MBS. Magnetic resonance angiography (MRA) also showed a positive effect on vascularization. Conclusion In pediatric moyamoya patients, MBS is recommended as secondary option as a response to failed mEDAS. Its clinical effectiveness was shown by analyzing TTP images and assisted by MRA and digital subtraction angiography.