Postoperative Hemorrhage in Patients with Aneurysms Associated with Arteriovenous Malformations. A Systematic Review...

To compare the rates of postoperative hemorrhages (PHs) for aneurysms associated with brain arteriovenous malformation (AVM) evaluating the lesion that was initially treated.

A systematic review of the literature was carried out following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The search was performed in PubMed, Embase, and Scopus. After the data extraction, the total numbers and percentages were calculated through summary statistics and were subject to meta-analysis. The methodological quality and risk of bias were assessed using the ROBINS-I tool and to determine the certainty of the evidence, we utilized the Grading of Recommendations, Assessment, Development, and Evaluation methodology.

Out of the 738 records screened, 28 studies were chosen for data extraction with a total of 1671 patients. Hemorrhagic presentation was observed between 38% and 100% of patients across the studies included. The pooled period prevalence of PH after intervention was 6% (95% confidence interval [CI = 0.03-0.07). Stratified analysis according to which lesion was treated first demonstrated a slightly lower rates of PH when aneurysms were treated first, compared when the AVM was managed first or if both lesions were treated simultaneously (P = 0.02). Rates of hemorrhage for lesions in the infratentorial location (0.21; 95% CI = 0.01-0.42) were much higher after intervention compared to noninfratentorial location (0.05; 95% CI = 0.03-0.07), and this difference reached statistical significance (P < 0.01).

Hemorrhage rates were lower when treating the aneurysm first, but their risk was higher when treating infratentorial lesions. The decision on which lesion should be treated first should be individualized according to the feeder vessels, the AVM and aneurysmal size, location, and overall functionality of the patients.