Fig. 4

The proportion of each treatment for patients with S–M grade III AVMs in the first and second periods of our study (a). The blue gridded area indicates the proportion of treatments including microsurgery (b), and the yellow gridded area indicates the proportion of treatments including stereotactic radiosurgery (c). Treatments including microsurgery decreased significantly (p = 0.003), and treatments including stereotactic radiosurgery increased significantly (p = 0.011) when comparing the first and second periods of our study. S: microsurgery, E: endovascular embolization, R: stereotactic radiosurgery, M: medical treatment