Title PageIntractable epidural effusion with infection after aneurysm surgery: a case report and literature reviewEthics statementWritten informed consent was obtained from the parents for the publication of this case report. The study protocol was approved by The Affiliated Huaian No.1 People’s Hospital of Nanjing Medical University.Declaration of conflicting interestThe authors declare that there is no conflict of interest.AcknowledgmentsWe express our gratitude to the patient’s family members for their co-operation.Funding informationNone.Author’s names and affiliations. Jiahui Liu :Huaian First People’s Hospital;Huaian,China; Email:1347217316@qq.com2. Kun Sun :Huaian First People’s Hospital;Huaian,China; Email:hayysk@njmu.edu.cn3. Jun Li :Huaian First People’s Hospital;Huaian,China; Email:skafpka@163.com4. Xiaodong Wang :Huaian First People’s Hospital;Huaian,China; Email:Wxdxa19800@126.com5.Corresponding author:Lianshu Ding , MD;Huaian First People’s Hospital;Huaian,China;223200Email: dlshu@163.comAuthor contributionsJiahui Liu: Conceptualization; data curation; formal analysis; methodology; project administration; resources; supervision; writing – original draft;Kun Sun: Conceptualization; data curation; formal analysis; methodology; project administration; resources; supervision; writing – review and editing.Jun Li: Conceptualization;data curation; resources;writing – review and editing. Xiaodong Wang: project administration; resources; supervision; writing – review and editing.Lianshu Ding: Conceptualization; data curation; formal analysis; investigation; methodology; project administration; resources; supervision; writing – review and editing.Key clinical messageThis case study presents a case of intractable epidural effusion combined with infection in a 53-year-old male following an aneurysm. The patient’s condition was refractory to conventional treatment, necessitating a high level of awareness, prompt recognition, and prompt debridement.KeywordsEpidural effusion, post-aneurysmal syndrome, subcutaneous effusion,epidural infection.IntroductionEpidural effusion following craniotomy is frequently observed in the context of cranial large bone flap surgery and cranial repair. In fact, the incidence may reach as high as 32.1% in posterior ethmoidal sinus approach surgery(1), particularly when the initial treatment is still unsatisfactory and intractable epidural effusion is considered. This latter condition is commonly referred to as subcutaneous effusion. It typically manifests between the second and fourteenth postoperative day, with an average time of appearance of 4.6 days. In clinical practice, cases of recalcitrant epidural effusion in patients with repositioned bone flaps after aneurysm clamping with concomitant infection are rare. It is therefore imperative to enhance awareness of recalcitrant epidural effusion with infection, to implement active prevention strategies and to ensure prompt treatment.