Objective We aimed to analyze the angioarchitecture characters and changes after combined bypass surgery (CBS) in pediatric moyamoya disease. Methods We retrospectively analyzed our database of consecutive patients with moyamoya angiopathy who received treatment. Only pediatric MMD cases aged between 3 to 19 years old whose pre- and post-operative imaging examinations including digital subtraction angiography and magnetic resonance imaging were enrolled in this study. The main trunk vessels stenosis and the collaterals from superficial-meningeal system and deep parenchymal system were evaluated before and after CBS. Results During short term follow-up period after the unilateral CBS, the stenosis of main trunk vessels both in operative (5.72.1 vs 6.81.8; P<0.001) and non-operative hemisphere (non-operative side 4.31.9 vs 5.72.1; P<0.001) progressed obviously. During the median follow-up period of 28.5 months after CBS, the decreasing of PCA-MCA anastomoses was much more significant (26 vs 6, P<0.001) than that of the PCA-ACA anastomoses (18 vs 19, P=0.807). Meanwhile, the subependymal anastomotic network could be relieved obviously (27 vs 2, P<0.001), while the inner thalamic and striatal anastomotic network had no significant change (31 vs 25, P=0.109). Conclusions The successful CBS could decrease the collaterals from PCA-MCA leptomeningeal system and the subependymal compensations in deep parenchyma significantly, while the main trunk stenosis would aggravate rapidly both in operative and non-operative hemisphere in short term after unilateral CBS. Therefore, strict and regular follow-up for the changes of vascular architecture and prompt surgical intervention for contralateral side might of benefit to pediatric MMD.

目的分析小儿烟雾病联合搭桥手术（CBS）后血管结构特点及变化。方法 我们回顾性分析了接受治疗的烟雾病血管病患者的数据库。本研究仅纳入年龄在 3 至 19 岁的儿童 MMD 病例，其术前和术后影像学检查包括数字减影血管造影和磁共振成像。评估CBS前后主要干血管狭窄程度以及浅脑膜系统和深部实质系统的侧支。结果 单侧CBS术后短期随访期间，手术侧（5.72.1 vs 6.81.8；P<0.001）和非手术侧（非手术侧4.31.9 vs 5.7）主干血管狭窄2.1；P<0。001) 进步明显。在 CBS 后 28.5 个月的中位随访期间，PCA-MCA 吻合的减少比 PCA-ACA 吻合更显着（26 vs 6，P<0.001）（18 vs 19，P=0.807） . 同时，室管膜下吻合网络明显缓解（27 vs 2，P<0.001），而内丘脑和纹状体吻合网络无明显变化（31 vs 25，P=0.109）。结论成功的CBS可使PCA-MCA软脑膜系统侧支循环明显减少，深部室管膜下代偿明显减少，而单侧CBS术后短期内手术和非手术半球主干狭窄均会迅速加重。所以，