A rare complication of autologous cranioplasty: symptomatic epidural fluid collection causing mass effect requiring removal of bone flap

Introduction and importance Cranial reconstruction after decompressive craniectomy is done usually at 20–25 per million people per year. The extra axial fluid collection is around 6% for subdural effusion and 6.1% for CSF leak and fistula. However, in Nepal, the overall complication of cranioplasty was 9% with collection of 4.1% and no any bone removal was done for epidural collection. Here I will be presenting a case that has rare complication of symptomatic epidural fluid collection after cranioplasty requiring removal of bone-flap. Case summary 45 years male underwent right Frontotemporoparietal Decompressive Craniectomy with Evacuation of Acute Subdural hematoma followed by lax duraplasty. After 2 months, he underwent autologous cranioplasty. On 5th POD, he had persistent headaches, became drowsy and GCS fell to 12 from 15. Immediate CT head revealed hypodense extradural fluid collection with midline shift and mass effect. Immediate removal of the bone flap was done and fluid was drained. He dramatically improved after operation and was discharged with GOS score of 4 after 10 days of hospital stay. Clinical discussion: Extradural fluid collection following cranioplasty is common complication but symptomatic fluid collection requiring removal of bone is not reported till date in Nepal. Conclusion Cranioplasty is common but the rare complication of symptomatic epidural fluid collection causing mass effect and requiring removal of the bone flap may occur. Prompt investigation and urgent management are crucial for the good outcome of the patient. Preventive strategies for epidural fluid collection should be taken in all cases of cranioplasty.