Relationship between preoperative external ventricular drainage and preoperative rebleeding in aneurysmal subarachnoid hemorrhage: A meta-analysis

Objective: To analyze published evidence on the relationship between preoperative external ventricular drainage (preop-EVD) and preoperative rebleeding (preop-rebleeding) in aneurysmal subarachnoid hemorrhage (aSAH). Method: A comprehensive search of three databases (PubMed, Ovid EMBASE, and The Cochrane Library) was conducted from their commencement to March 31, 2022. We collected studies reporting preop-EVD of rupture aneurysms while preop-rebleeding events were documented in these studies. We also extracted information on risk factors for preop-rebleeding from the studies and used Review Manager version 5.3 software to analyze. Results: A total of 3671 cases from 14 articles were enrolled in this meta-analysis. Preop-rebleeding rate was 11.04 % (106/960) and 9.22 % (250/2711) in preop-EVD group and control group, respectively. The study lacked power to conclude a clinically significant increase in preop-rebleeding risk (OR=1.60, 95 %CI:0.82-3.22). Fisher> 2 (OR=1.86), modified Fisher> 2 (OR=7.57), World Federation of Neurological Surgeons (WFNS)> 2 (OR=4.39) and aneurysm size > 1 cm (OR=3.01) were risk factors of preop-rebleeding. Patients with Hunt-Hess (HH)> 2 showed a higher preop-rebleeding trend compared to HH <= 2, but the result did not reach a statistical difference (OR=6.79, P = 0.06). No difference in preop-rebleeding risk between anterior circulation aneurysms and posterior circulation aneurysms. Hydrocephalus had also been shown to be unrelated to higher preoprebleeding rate. Conclusions: Current evidence does not support that preop-EVD significantly increases the risk of rebleeding prior to aneurysm repair. Patients with poorer clinical status on admission and aneurysms size > 1 cm are at a higher risk of preop-rebleeding.

Automated summary

This study analyzed the relationship between preoperative external ventricular drainage (preop-EVD) and preoperative rebleeding in aneurysmal subarachnoid hemorrhage. The results showed that preop-EVD does not significantly increase the risk of preoperative rebleeding prior to aneurysm repair. Patients with poorer clinical status on admission and aneurysms larger than 1 cm are more likely to experience preoperative rebleeding.