Supplementary Material for: Postoperative complications of microscopic fenestration for middle fossa arachnoid cysts: a retrospective study of 38 cases and literature review

Introduction: Middle fossa arachnoid cyst (MFAC) is one of the most common cranial cysts in children, and the various postoperative complications following cyst fenestration represent a major concern. We conducted a retrospective study in our department and performed a systematic review of the literature to identify the risk factors for complications. Methods: A retrospective survey was conducted on 38 patients with MFAC (< 14 years) who underwent microscopic fenestration from January 2019 to December 2020. Postoperative complications, including postoperative hemorrhage/hematoma, subdural hygroma (SH), cranial nerve palsy, central nervous system infection (PCNSI), and cerebrospinal fluid (CSF) leak, were collected. A systematic PubMed search for cohort studies on surgically treated MFAC published after 1980 was performed. The postoperative complications in the included studies were illustrated. Results: The overall complication rate in our series was 7.9%, among whom, nine patients (23.7%) developed postoperative SH, one of which required cyst-peritoneal shunting. Patients who developed SH were significantly younger (4.0 ± 1.8 vs 6.3 ± 3.4 years, p = 0.012). Binary logistic analysis showed that a lower age could be a risk factor for developing SH (odds ratio: 0.738, p = 0.067). One patient developed a subdural hematoma. No cranial nerve palsy or CSF leak was observed. Eighteen studies were included in the systematic review, comprising 649 cases of MFAC. The most common complication was SH (4.9%), and the postoperative complication rates were similar between the microscopic and endoscopic techniques. Conclusion: The complication rate of MFAC fenestration is considerable. SH is the most common postoperative complication, and it mostly occurs in young children. Strict surgical indications should be applied for young children.

引言：颅中窝蛛网膜囊肿（Middle fossa arachnoid cyst, MFAC）是儿童最常见的颅内囊肿之一，囊肿开窗术后的各类术后并发症是临床关注的重点问题。本研究在我科开展了一项回顾性调研，并对相关文献进行系统综述，以明确并发症发生的危险因素。

方法：回顾性分析2019年1月至2020年12月间收治的38例年龄<14岁的MFAC患儿，所有患儿均接受显微囊肿开窗术。收集术后并发症数据，包括术后出血/血肿、硬膜下积液（subdural hygroma, SH）、脑神经麻痹、中枢神经系统感染（primary central nervous system infection, PCNSI）以及脑脊液（cerebrospinal fluid, CSF）漏。随后在PubMed数据库中系统检索1980年之后发表的关于手术治疗MFAC的队列研究，对纳入研究中的术后并发症情况进行汇总分析。

结果：本队列的总体并发症发生率为7.9%，其中9例患儿（23.7%）出现术后硬膜下积液，1例需行囊肿-腹腔分流术。发生硬膜下积液的患儿年龄显著低于未发生该并发症者（4.0±1.8岁 vs 6.3±3.4岁，p=0.012）。二元logistic回归分析显示，更低的年龄可能是发生硬膜下积液的危险因素（优势比：0.738，p=0.067）。另有1例患儿出现硬膜下血肿，未观察到脑神经麻痹或脑脊液漏病例。本次系统综述共纳入18项研究，合计涵盖649例MFAC病例。最常见的术后并发症为硬膜下积液（发生率4.9%），显微手术与内镜手术的术后并发症发生率无显著差异。

结论：MFAC囊肿开窗术的并发症发生率不容忽视。硬膜下积液是最常见的术后并发症，且多发生于幼儿群体，因此对幼儿患者应严格把握手术适应证。