Repeat endoscopic third ventriculostomy: is it worth trying?

OBJECT: The goal of this study was to evaluate the safety, efficacy, and indications for repeat endoscopic third ventriculostomies (ETV). METHODS AND RESULTS: We reviewed the records of 20 patients who had undergone repeat ETV from 1987 to 1999. Their ages ranged from 8 months to 53 years (mean 17 years). The primary etiologies of hydrocephalus were: primary aqueductal stenosis (9 cases), tumor (5), Chiari malformation (2), prior infection (2), prior intraventricular hemorrhage (1), and blocked foramen of Monro (1 patient). The interval between the first and second ETVs ranged from 8 days to almost 6 years (mean 12.8 months). The intraoperative findings at repeat surgery were: occlusion of the primary orifice by scar (10 cases), virginal floor of the third ventricle (5 cases), pinhole ventriculostomy (3 cases), incompletely penetrated membrane (1 case), and blood clot occluding the orifice (1 case). The follow-up period ranged from 3 to 47 months (median 20 months). Repeat ETV was successful in 13 patients (65%). These patients did not require further shunting or other procedures during follow-up. Seven patients (35%) required placement of a shunt after repeat ETV. Several complications were observed in 1 patient (5%), including seizures, elevated ICP, bilateral pulmonary edema, and cardiac arrhythmia. This patient ultimately recovered fully; the ETV was successful, and the patient did not require a shunt. CONCLUSIONS: Based on the experience of this group of patients, repeat ETV is as effective and as safe as a primary ETV procedure, and should be attempted in selected patients.

Application of the orbito-cranial approach in pediatric neurosurgery.

OBJECTIVE: This study evaluates the benefits of and indications for the orbito-cranial approach (OCA) in pediatric patients. METHODS AND RESULTS: The authors report their recent experience of using the OCA in 9 pediatric patients, 6 boys and 3 girls. The patients' ages ranged from 3 to 17 years (mean 9.6+/-5.16 years). Follow-up periods varied between 6 and 21 months (mean 12.6+/-5.9 months). Five patients were operated on for craniopharyngiomas, 2 for chiasmatic-hypothalamic astrocytomas, 1 for a recurrent hypothalamic gangliocytoma, and 1 for a hypothalamic hamartoma. In 7 cases a neuronavigation system (BrainLab) was utilized. The lesions were removed totally in 5 patients, near-totally in 1, subtotally in 2, and partially in 1 patient. An average increase of 30% in the area of vertical exposure significantly decreased the need for brain retraction. There was no mortality in this series. The only complications connected with the surgical approach were transient subgaleal cerebro-spinal fluid collections in 7 of 9 children and a subgaleal-peritoneal shunt placement in another patient. CONCLUSIONS: Our experience with this series of patients suggests that the OCA is as safe and beneficial in pediatric patients as it is in adults. It facilitates tumor removal by providing shorter access to and better exposure of the suprasellar area, thereby minimizing brain retraction.

Outlet fenestration for isolated fourth ventricle with and without an internal shunt.

Conventional shunting of isolated fourth ventricle is notorious for leading to frequent and severe complications. We present four patients with isolated fourth ventricle who have been treated with open posterior fossa surgery together with either outlet fenestration alone or outlet fenestration and a fourth ventricle-spinal subarachnoid space (SSS) shunt. A survey of the relevant literature did not yield any other case reports of fourth ventricle shunting to the SSS under such circumstances. This paper discusses the reasons for choosing this mode of treatment. The main advantage of this technique is that the catheter is inserted along the anatomical long axis of the fourth ventricle. This positioning lessens the possibility of irritating or penetrating the brain stem. Moreover, as a more physiological solution, the shunt does not require a valve system. Because of these advantages, internal fourth ventricle-SSS shunting is proposed as a valid alternative to the "classic" fourth ventriculo-peritoneal shunt.

Ascites following ventriculoperitoneal shunting in children with chiasmatic-hypothalamic glioma.

OBJECT: Optic pathway gliomas in children can involve the optic nerve, chiasm, and hypothalamus. This uncommon, slowly growing tumor can cause hydrocephalus, which usually requires placement of a ventriculoperitoneal (VP) shunt. Symptomatic ascites may occasionally develop as a complication of the VP shunt procedure. The purpose of this study was to assess the risk factors associated with CSF ascites in children with optic pathway gliomas. METHODS: Twenty-two children (ages 4 months to 20 years) with chiasmatic-hypothalamic optic gliomas participated in this study. Four children were diagnosed with a chiasmatic glioma, 7 with a hypothalamic glioma, and 11 with a glioma involving both the optic chiasm and hypothalamus. Twelve children (55%) developed hydrocephalus and required VP shunt placement. Of the 12 shunted children, 4 (33%) developed CSF ascites. The incidence of ascites was not associated with infection, tumor metastasis, or multiple shunt revisions. There was no correlation with the size of the tumor. All 4 children with ascites had tumor involving the optic chiasm or optic nerve. None of the 5 children with pure hypothalamic glioma who underwent VP shunt placement have developed ascites. Among the 7 children suffering from chiasmatic or optic nerve gliomas who developed hydrocephalus, the risk of developing ascites as a complication of VP shunt placement was 57% (4/7). Ventriculoatrial (VA) shunt was the treatment of choice for children with VP shunt-induced ascites. After placement of a VA shunt the ascites subsided. The children did not develop further complications. CONCLUSION: We conclude that glioma involving the optic chiasm or nerve is associated with a high risk of developing ascites following VP shunt placement. VA shunt may be the treatment of choice for children with chiasmatic or optic nerve gliomas who require a CSF diversion procedure.

No evidence of epilepsy following endoscopic third ventriculostomy: a short-term follow-up.

Patients with ventriculo-peritoneal shunts are predisposed to various complications, including the appearance of seizures over time. The high rate of complications prompted an interest in alternative procedures such as endoscopic third venticulostomy (ETV) in selected patients. From 1996 to 1998, 42 patients underwent ETV in our center. Of the 27 operated children who were followed for an average of 32 months, none experienced seizures during that time. We conclude that, in addition to other benefits, ETV minimizes the risk of epilepsy following shunt insertion, probably due to the lack of direct cortical insult.

Surgical treatment of hypothalamic hamartoma and refractory seizures: a case report and review of the literature.

Refractory gelastic seizures are often associated with hypothalamic hamartoma (HH). Presurgical evaluation in such children often points to a distinct cortical region as the source of the seizures. A case of a child with HH and refractory seizures is presented. Video-EEG monitoring revealed a well-defined epileptic focus in the left frontal region. In accordance with the current understanding of the nature of hamartoma-related seizures, the hamartoma was resected. Follow-up evaluations revealed a marked improvement in seizure frequency and global functioning.

Increasing chronic subdural hematoma after endoscopic III ventriculostomy.

OBJECT: Endoscopic III ventriculostomy (ETV) is an effective and a rather safe treatment for noncommunicating hydrocephalus secondary to aqueductal stenosis and other obstructive pathologies. Though not devoid of risk, ETV is increasingly replacing shunt operations, and it prevents related complications, including overdrainage. METHODS: We report a rare case of a large chronic subdural hematoma (ChSDH) after ETV in a patient with aqueductal stenosis. Three weeks after he was shunted elsewhere, he presented to us with clinical symptoms of intracranial hypotension and overdrainage. ETV was performed and the shunt removed uneventfully. On routine postoperative MRI a few weeks later, a large ChSDH was noted, the patient being totally asymptomatic. Since the ChSDH grew significantly, causing a mass effect on the follow-up MRI, it was finally drained. Large and increasing ChSDHs have previously been reported secondary to overdrainage after shunt placement, but not after ETV. CONCLUSIONS: We conclude that though rare, a ChSDH may evolve even after ETV, if there is a substantial decrease in previously elevated intracranial pressure.