Modulation of physiological hemostasis by irrigation solution: comparison of various irrigation solutions using a mouse brain surface bleeding model.

OBJECT: Intraoperative bleeding often obscures the surgical field and may cause neurological damage. The irrigation fluids used during surgery might affect physiological hemostasis because they modulate the extracellular fluid composition of the bleeding area directly. The authors therefore investigated the influence of irrigation fluid on hemostasis in a mouse brain surface bleeding model. METHODS: The cerebral cortices of ddY strain mice were exposed under irrigation with normal saline, lactated Ringer (LR) solution, or artificial CSF (ACF-95). To investigate the influence of electrolytes, calcium, potassium, or both were also added to the saline. After 10 minutes of irrigation at 100 ml/hour, sequential photographs of the surgical area were taken with a microscope, and the number of bleeding points was counted visually. Irrigation and counting were performed in a masked manner. RESULTS: There were significantly more bleeding points after irrigation with normal saline than with ACF-95; LR solution had a similar effect on physiological hemostasis as ACF-95. Saline augmented with calcium or potassium and calcium was superior to normal saline in terms of hemostasis. CONCLUSIONS: The authors demonstrated that the irrigation fluid used in neurosurgery affects bleeding at the surgical site. To avoid surgical site bleeding, ACF-95 and LR solution should be used as irrigation fluids instead of normal saline. The calcium and potassium content of irrigation solutions seems to be important in hemostasis.

Management and prognosis of cysts developed on long-term follow-up after Gamma Knife radiosurgery for intracranial arteriovenous malformations.

BACKGROUND: Delayed cyst formation is a well-recognized complication after radiosurgery for intracranial AVM. The objective of the present study was the evaluation of the different management options for these lesions and the corresponding prognosis of patients. METHODS: Between 2000 and 2005, 12 patients with intracranial AVM initially treated by GKR were reevaluated at Tokyo Women's Medical University because of delayed cyst formation in the vicinity of the target area. There were 7 men and 5 women. The mean age of the patients was 31.8 years at the time of GKR and 41.1 years at the time of complication. The average period between treatment and diagnosis of the complication constituted 6.7 years. All AVMs had lobar location and showed complete angiographic obliteration after GKR. RESULTS: The most common neurological signs and symptoms at the time of cyst presentation were headache (10 cases) and seizures (4 cases). Two patients were asymptomatic. Three patients underwent surgery soon after the diagnosis of the cyst, whereas initial observation was done in another 9. Among the latter, 5 patients had to be treated surgically thereafter because of persistent or aggravated neurological symptoms associated with radiological cyst expansion. Four other patients, including both asymptomatic ones, are in stable condition without surgery. Follow-up after treatment of the cyst varied from 7 to 60 months (average, 34.3 months). All patients are in good condition. CONCLUSIONS: Although delayed formation of cysts after GKR for intracranial AVM should be considered as a complication of the radiosurgical treatment, it has a relatively good prognosis. Observation can be recommended as initial option for compensated and asymptomatic patients.

Neurofiberscopic biopsy of tumors of the pineal region and posterior third ventricle: indications, technique, complications, and results.

OBJECTIVE: Evaluation of results of the neurofiberscopic biopsy of tumors of the pineal region and posterior third ventricle. METHODS: From 2001 to 2004, 23 patients (mean age, 30.6 yr) with tumors located in the pineal region or posterior third ventricle underwent neurofiberscopic biopsy with simultaneous third ventriculostomy. The procedure was indicated for verification of the histological diagnosis of the neoplasm, which was planned to be treated by radiotherapy and/or chemotherapy without open surgery (eight patients), establishment of the pathological diagnosis for further choice of the most appropriate treatment strategy (11 patients), differentiation of the recurrent neoplasm and radiation necrosis (two patients), and decompression of the large tumor-associated cyst (two patients). In six previously shunted patients, substitution of the ventriculoperitoneal shunt on the third ventricle stoma was performed. RESULTS: There was no postoperative mortality or permanent morbidity. In all cases, the obtained tissue sample was sufficient for pathological diagnosis. Transient postoperative complications included fever (15 patients), nausea and vomiting (three patients), and diplopia (one patient). On the long-term follow-up, delayed third ventricular stoma failure caused by tumor regrowth and scar formation was found in one patient, and dissemination of the malignant glioma through the subarachnoid space was found in another patient. CONCLUSION: Neurofiberscopic biopsy represents a useful method for sampling of tumors of the pineal region and posterior third ventricle, which can be effectively used in both previously shunted and shunt-free patients.

Neurofiberscope-guided management of slit-ventricle syndrome due to shunt placement.

OBJECT: The purpose of this study was to evaluate an original neurofiberscope-guided strategy for the management of slit-ventricle syndrome that occurs after shunt placement. METHODS: Between 1995 and 2003 15 patients with slit-ventricle syndrome (mean age 14.2 years) underwent endoscopic third ventriculostomy (ETV) and shunt removal. During the initial surgical procedure a neurofiberscope with a small outer diameter was inserted along the shunt tube into the collapsed ventricle for endoscopically controlled removal of the ventricular catheter and evaluation of brain compliance. If the latter was sufficiently preserved, primary ETV and shunt removal were performed (four cases). If brain compliance seemed to be significantly reduced, endoscopically controlled replacement of the ventricular catheter and implantation of the Codman-Hakim programmable valve shunt device were performed (11 cases). In these patients, delayed ETV and shunt removal were performed later (mean period of 16.3 months). No medical or surgical complications occurred in any case. Follow up ranged from 6 to 84 months (mean 31.1 months; median 22 months). All patients became shunt independent and 13 became symptom free. Overall, the size of the ventricles returned to normal in five cases, became slightly dilated in nine, and moderately dilated in one. CONCLUSIONS: Neurofiberscope-guided treatment of slit-ventricle syndrome involving shunt removal and ETV appears to be beneficial; all patients in this series were symptom free and shunt independent at the end of follow up.

Double-endoscopic approach for management of convexity arachnoid cyst: case report.

BACKGROUND: Controversy exists about the best treatment modality for arachnoid cysts. Widely accepted neurosurgical options include craniotomy with open resection of the cyst walls, shunting procedures and stereotactic fenestration of the cyst cavity. Recently, neuroendoscopic approach showed its effectiveness for treatment of these lesions. CASE DESCRIPTION: In the presented case the large convexity arachnoid cyst was diagnosed in a 22-year-old woman with head dullness and local bone bulging. No neurologic signs were found. Surgery was performed by double-neuroendoscopic approach with simultaneous use of two flexible ventriculofiberscopes, which permitted wide resection of the inner cyst wall. Complete resolution of symptoms was noted soon after surgery. CONCLUSION: Double-endoscopic approach might be useful for complex neuroendoscopic procedures that need different simultaneous surgical actions, particularly for cases of large arachnoid cysts.

Histologic diagnosis and management of hypothalamic tumors in children by the use of newly developed flexible neuroendoscopes.

Hypothalamic tumors are difficult to treat surgically, and chemotherapy and/or radiation are given based on the histology and the neuraxis staging of the tumors. We have developed flexible neuroendoscopes (Yamadori-type 8 and 9) which have excellent image quality and maneuverability as well as capabilities for biopsy and electrocoagulative debulking of the cystic tumors. We report the successful application of the neuroendoscopes to 10 children with hypothalamic tumors diagnosed with computed tomography or magnetic resonance imaging. Histologic diagnosis was obtained from all the patients. Cystic tumors were evacuated, hydrocephalus managed with endoscopic operations, and some benign tumors were removed totally. The relatively non-invasive approach reported here would represent a significant technical advance in the diagnosis and management of hypothalamic and other ventricular tumors.