目的·在量化四叠体池蛛网膜囊肿（quadrigeminal cistern arachnoid cyst，QAC）体积和脑积水的基础上，初步分析儿童QAC的临床特点和不同术式的疗效，以期提高对该疾病的认知和诊治水平。方法·选择上海交通大学医学院附属新华医院2015年1月至2025年6月期间收治的27例QAC患儿，通过头颅磁共振成像（magnetic resonance imaging，MRI）和计算机断层扫描（computed tomography，CT）检查计算QAC体积和Evans指数，回顾分析其一般资料、症状体征、影像学表现、手术情况和预后情况。结果·27例患儿年龄分布0 d~150个月，男女人数比为1.08∶1，术前QAC中位体积为34 402 （15 022，138 478）mm³，中位Evans指数为0.29（0.24，0.48）。其中12例患者无症状，多在6月龄以下；15例存在颅内压增高、抽搐、肌力下降或瞬目频繁等症状，多在6月龄以上。27例患者共进行了33次手术，其中1次手术22例，2次手术4例，3次手术1例。内镜下开窗造瘘术（endoscopic fenestration，EF）、EF联合内镜下第三脑室底造瘘术（endoscopic third ventriculostomy，ETV）、脑室腹腔分流术（ventriculoperitoneal shunt，VP）的再手术率依次为15.8%、40.0%和0。总再手术率为18.5%，其中6月龄以下的患儿行多次手术的概率更高。27例患儿随访3个月~10年，88.9%的患儿术后3个月QAC体积明显变小，92.3%的患儿临床表现明显好转。未发现EF、EF+ETV及VP手术之间存在疗效差异。术后12个月和24个月的QAC体积变化及Evans指数变化具有一定差异，术前QAC体积≥50 000 mm³的患儿上述指标更倾向于变小。结论·QAC的发生几乎无性别差异，可以肌力下降和瞬目频繁为首发症状。年龄和症状之间可能具有一定相关性。QAC再手术率较低，手术疗效显著，术后短期QAC体积明显缩小，症状多消失或改善。暂未发现EF、EF+ETV和VP手术之间具有疗效差异，术前QAC体积较大的患儿长期预后可能更好。

Objective ·To quantify the volume of quadrigeminal cistern arachnoid cysts (QACs) and hydrocephalus indicators, and analyze the clinical features of QACs in children and the efficacy of different surgical techniques, with the goal of improving understanding, diagnosis, and treatment of this condition. Methods ·A retrospective analysis was conducted on 27 pediatric patients with QACs treated at Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, between January 2015 and June 2025. The volume of QACs and the Evans index were calculated by using cranial magnetic resonance imaging (MRI) and computed tomography (CT). Clinical data, including demographics, symptoms/signs, imaging findings, surgical procedures, and follow-up outcomes, were reviewed. Results ·The cohort (age range: 0 d‒150 months; male-to-female ratio: 1.08∶1) had a median preoperative QAC volume of 34 402 (15 022, 138 478) mm³ and a median Evans index of 0.29 (0.24, 0.48). Among the cases, twelve were asymptomatic and were predominantly infants under 6 months of age, whereas fifteen symptomatic cases—presenting with intracranial hypertension, seizures, limb weakness, or frequent blinking—were mostly older than 6 months. A total of 33 surgeries were performed (one surgery: 22 cases; two surgeries: 4 cases; three surgeries: 1 case). Reoperation rates were 15.8% for endoscopic fenestration (EF), 40.0% for EF combined with endoscopic third ventriculostomy (ETV), and 0 for ventriculoperitoneal shunt (VP). The overall reoperation rate was 18.5%, with infants under 6 months having a higher probability of requiring repeat surgeries. During follow-up, 88.9% of patients showed significant QAC volume reduction at 3 months postoperatively, and 92.3% exhibited clinical improvement. No efficacy differences were found among EF, EF+ETV, and VP procedures to date. Patients with larger preoperative QACs (≥50 000 mm³) showed more pronounced reductions in QAC volume and Evans index at 12 and 24 months postoperatively. Conclusion ·QACs exhibit no gender predilection and may present with limb weakness or frequent blinking as initial symptoms. Age and symptoms may be correlated. Surgical outcomes are favorable, with low reoperation rates, significant short-term volume reduction, and symptom resolution. No difference in efficacy is observed among EF, EF+ETV, and VP procedures. Larger QACs are associated with a better long-term prognosis.