Comparison of lumbar drainage and external ventricular drainage for clearance of subarachnoid clots after Guglielmi detachable coil embolization for aneurysmal subarachnoid hemorrhage.

OBJECTIVE: Subarachnoid clots play an important role in development of delayed vasospasm after subarachnoid hemorrhage (SAH). The purpose of this study was to compare clearance of subarachnoid clots using external ventricular drainage (EVD) or lumbar drainage (LD) after Guglielmi detachable coil (GDC) embolization for aneurysmal SAH. METHODS: The subjects were 51 treated with GDC coil embolization for aneurysmal Fisher group 3 SAH within 72 h of ictus. Software-based volumetric quantification of the subarachnoid clots was performed on CT scans and the hemoglobin (Hb) level was measured in CSF drained from each catheter. RESULTS: Clearance of subarachnoid clots was more rapid in patients treated with LD (n=34) compared to those treated with EVD (n=17). The Hb level in CSF was significantly higher in the LD group on Days 4-5 after onset of SAH (P<0.05), but was higher in the EVD group on Days 8-9. The incidence of symptomatic vasospasm did not differ between the two groups. The rate of occurrence of a new low density area on CT scans was higher in patients treated with EVD, but not significantly higher than the rate in the LD group. CONCLUSION: GDC embolization followed by lumbar drainage accelerates the reduction of subarachnoid clots, but EVD may contribute to stasis of hemorrhage within subarachnoid spaces.