Effect of Cisternal Drainage after Early Operation for Ruptured Intracranial Aneurysms
The effect of postoperative drainage of cerebrospinal fluid (CSF) was assessed in 132 patients who underwent early surgery for ruptured aneurysms. For comparison of cisternal drainage (n=101) versus no drainage (n=31), we paid particular attention to long-term outcome (morbidity and mortality) and the occurrence of cerebral vasospasm and hydrocephalus. Present results demonstrated that cisternal drainage could contribute to lessening of mortality in preoperative clinical (Hunt & Kosnik) grade IV patients and of morbidity in grade III patients, and to the relatively low incidence of vasospasm even in the patients whose CT scans showed large subarachnoid clots. CSF drainage has been recommended as a useful procedure because it has been shown to improve the prognosis through prophylaxis and relief of vasospasm and removal of blood-contaminated CSF. However, hydrocephalus and shunting operation were most frequent in the group with cisternal drainage. This difference suggest that the establishment of drainage might aggravate subarachnoid fibrosis and impair CSF absorption. In addition, the incidence of hydrocephalus in the group with high-volume drainage was three times that in the group without drainage (p>0.05) and twice that in the group with low-volume drainage (Table). Thus, present study suggest that it would be important to regulate the flow and or pressure of CSF drainage after early operation for ruptured aneurysms.