Effect of Surgical Arachnoid Plasty on Functional Outcome in Aneurysmal Subarachnoid Hemorrhage

OBJECTIVE: Various techniques have been performed to reduce subarachnoid clotting during aneurysmal neck clipping surgery. We considered that maintaining the physiologic cerebrospinal fluid circulation by performing arachnoid plasty after clipping during surgery would lead to the accelerated clearance of the subarachnoid clot. METHODS: Patients in a prospectively maintained aneurysmal subarachnoid hemorrhage (aSAH) database at our institution and with aSAH that fulfilled the criteria were selected for this study. The incidence of delayed cerebral ischemia, angiographic vasospasm, 3-month functional outcome, and the amount of subarachnoid clot on computed tomography were compared between the 2 groups after matching. RESULTS: From 2006 through 2016, 228 clipping cases met the inclusion criteria. Using propensity score matching, 89 cases of clipping without arachnoid plasty were matched to 89 cases of clipping with arachnoid plasty. Univariate analyses showed that arachnoid plasty significantly reduced the occurrence of hydrocephalus and incidence of poor outcome. Arachnoid plasty statistically significantly reduces the occurrence of hydrocephalus (odds ratio 0.267, 95% confidence interval 0.074-0.963, P < 0.05). Multivariate analysis also showed that arachnoid plasty was the factor reducing poor outcome at 3 months after aSAH (odds ratio 0.222, 95% confidence interval 0.075-0.661, P < 0.01). CONCLUSIONS: The present study suggests that good hematoma clearance due to arachnoid formation reduced brain damage, cerebral vasospasm, and hydrocephalus, resulting in significantly fewer cases with poor functional prognosis. It therefore follows that procedures such as arachnoid plasty should be taken into consideration in order to improve outcome in surgical clipping.