Basal cisternostomy as an adjunct to decompressive hemicraniectomy in moderate to severe traumatic brain injury: a systematic review and meta-analysis

Background: Basal cisternostomy (BC) is a surgical technique to reduce intracranial hypertension following moderate to severe traumatic brain injury (TBI). As the efficacy and safety of BC in patients with TBI has not been well-studied, we aim to summarize the published evidence on the effect of BC as an adjunct to decompressive hemicraniectomy (DHC) on clinical outcome following moderate to severe TBI.

Methods: A systematic literature review was carried out in PubMed/MEDLINE and EMBASE to identify studies evaluating BC as an adjunct to decompressive hemicraniectomy (DHC) in moderate to severe TBI. Random effects meta-analysis was performed to calculate summary effect estimates.

Results: Eight studies reporting on 1345 patients were included in the qualitative analysis, of which five (1206 patients) were considered for meta-analysis. Overall, study quality was low and clinical heterogeneity was high. Adjuvant BC (BC + DHC) compared to standalone DHC was associated with a reduction in the length of stay in the ICU (Mean difference [MD]: -3.25 days, 95% CI: -5.41 to -1.09 days, p = 0.003), significantly lower mean brain outward herniation (MD: -0.68 cm, 95% CI: -0.90 to -0.46 cm, p < 0.001), reduced odds of requiring osmotherapy (OR: 0.09, 95% CI: 0.02 to 0.41, p = 0.002) as well as decreased odds of mortality at discharge (OR 0.68, 95% CI: 0.4 to 0.96, p = 0.03). Adjuvant BC compared to DHC did not result in higher odds of a favourable neurological outcome (OR = 2.50, 95% CI: 0.95-6.55, p = 0.06) and did not affect mortality at final follow-up (OR: 0.80, 95% CI: 0.17 to 3.74, p = 0.77).

Conclusion: There is insufficient data to demonstrate a potential beneficial effect of adjuvant BC. Despite some evidence for reduced mortality and length of stay, there is no effect on neurological outcome. However, these results need to be interpreted with caution as they carry a high risk of bias due to overall scarcity of published clinical data, technical variations, methodological differences, limited cohort sizes, and a considerable heterogeneity in study design and reported outcomes.