Pneumocephalus after surgical evacuation of chronic subdural hematoma: Is it a serious complication?

Background: Pneumocephalus is commonly encountered after surgical evacuation of chronic subdural hematoma (CSDH). This study was done to study the incidence, clinical presentation, and management of patients who developed pneumocephalus after surgical evacuation of CSDH. Materials and Methods: This prospective study was carried out on consecutive 50 patients who had received surgical treatment for CSDH. All the patients included were followed-up postoperatively with regular clinical and computed tomography (CT) examinations immediately postoperatively, before discharge, and 2 months after surgery. Pneumocephalus was classified into simple and tension, based upon the clinical and radiological criteria. The neurologic grading system of Markwalder et al was used to evaluate the surgical results. Results: The immediate postoperative CT scan showed pneumocephalus in 22 patients (44%). Tension pneumocephalus was found in two patients who did not require any further surgery. There was statistically significant increase in the incidence of pneumocephalus (immediate and postoperative) in the patients aged over 60 years as well as those presenting with a midline shift more than 5 mm in their CT scan. With regard to the 22 cases of pneumocephalus, good postoperative results were found in 16 patients (73%), while bad results were found in 6 patients (27%). No statistically significant difference in the outcome between patients who had pneumocephalus after surgery and those who had not. Conclusion: Pneumocephalus after surgical evacuation of CSDH is a common finding in the immediate CT scan as well as at time of discharge. Tension pneumocephalus may not require surgical intervention and simple aspiration of air using a syringe may be sufficient.