BACKGROUND: Opening the arachnoid membrane causes leakage of the cerebrospinal fluid (CSF). CSF spillage and collection in the subdural, epidural, and/or subcutaneous space are occasionally seen on a postoperative CT scan. Closure of the arachnoid membrane is considered to be unnecessary because most of the fluid in the extracerebral space is temporary and disappears spontaneously. However, in some cases, this CSF collection results in serious complications such as brain compression, extracerebral hematoma, intractable meningitis, and skin problems. In this study for prevention of CSF leakage, the arachnoid membrane was tightly closed with 10-0 nylon after a small opening was made for cerebrovascular bypass surgery. METHODS: The arachnoid membrane closure was performed in 18 patients (20 sides) after bypass surgery between 1994 and 1995. As a control, 51 patients (57 sides) had conventional bypass surgery without the arachnoid membrane closure. RESULTS: The radiological findings revealed that only one (5%) of the patients had a small fluid collection after arachnoid membrane closure, which was significantly lower than the control (49%). CONCLUSION: Arachnoid membrane closure is a simple technique and is effective for prevention of postoperative extracerebral CSF collection.
BACKGROUND: Opening the arachnoid membrane causes leakage of the cerebrospinal fluid (CSF). CSF spillage and collection in the subdural, epidural, and/or subcutaneous space are occasionally seen on a postoperative CT scan. Closure of the arachnoid membrane is considered to be unnecessary because most of the fluid in the extracerebral space is temporary and disappears spontaneously. However, in some cases, this CSF collection results in serious complications such as brain compression, extracerebral hematoma, intractable meningitis, and skin problems. In this study for prevention of CSF leakage, the arachnoid membrane was tightly closed with 10-0 nylon after a small opening was made for cerebrovascular bypass surgery. METHODS: The arachnoid membrane closure was performed in 18 patients (20 sides) after bypass surgery between 1994 and 1995. As a control, 51 patients (57 sides) had conventional bypass surgery without the arachnoid membrane closure. RESULTS: The radiological findings revealed that only one (5%) of the patients had a small fluid collection after arachnoid membrane closure, which was significantly lower than the control (49%). CONCLUSION:Arachnoid membrane closure is a simple technique and is effective for prevention of postoperative extracerebral CSF collection.