Effect of lamina terminalis fenestration on cerebral vasospasm after aneurysmal subarachnoid haemorrhage: a systematic review and meta-analysis.

BACKGROUND

Cerebral vasospasm and delayed cerebral ischaemia (DCI) remain major determinants of poor outcomes following aneurysmal subarachnoid haemorrhage (aSAH). Fenestration of the lamina terminalis (FLT) has been proposed as an adjunctive microsurgical maneuver to improve cerebrospinal fluid (CSF) circulation and facilitate clot clearance, potentially reducing the incidence of vasospasm. This systematic review and meta-analysis aimed to evaluate whether FLT performed during aneurysm clipping mitigates the occurrence of clinical vasospasm and improves postoperative outcomes.

METHODS

A comprehensive literature search of PubMed, Embase, and Google scholar databases was conducted up to January 2025, following PRISMA guidelines. Studies comparing microsurgical clipping with and without FLT in patients with ruptured intracranial aneurysms were included. Data were pooled using a random-effects model, with odds ratios (ORs) and 95% confidence intervals (CIs) calculated for clinical vasospasm.

RESULTS

Four studies encompassing 365 patients (182 FLT, 183 non-FLT) met inclusion criteria. Pooled analysis demonstrated a significant reduction in clinical vasospasm with FLT compared to non-fenestrated cases (OR 0.44; 95% CI 0.21-0.94; p = 0.03), with moderate heterogeneity (I2=52.1%). Leave-one-out sensitivity analysis confirmed the stability of these findings, with pooled odds ratios ranging from 0.33 to 0.57, all favoring FLT. Visual inspection of the funnel plot did not reveal significant publication bias. Definitions of clinical vasospasm varied across studies, and secondary outcomes (mortality, functional outcome, hydrocephalus, length of stay) were inconsistently reported, precluding quantitative synthesis.

CONCLUSION

FLT may reduce clinical vasospasm incidence after aneurysm clipping. However, limited data and heterogeneity restrict definitive conclusions, and further prospective studies are needed to determine its effect on long-term outcomes.