Vincenzo Trischitta

Endoscopic third ventriculostomy in the treatment of hydrocephalus in posterior fossa tumors in children

ObjectThe purpose of the present study is to assess the effectiveness of endoscopic third ventriculostomy (ETV) in children with hydrocephalus related to posterior fossa tumors.MethodsBetween September 1999 and December 2002, 63 children with posterior fossa tumors were treated at Santobono Hospital in Naples, Italy. Twenty-six patients had severe hydrocephalus. In order to relieve intracranial hypertension before tumor removal, 20 were treated with ETV, and 6 with ventriculo-peritoneal (VP) shunts. Twenty patients with mild hydrocephalus were treated with diuretics, corticosteroid agents, and early posterior fossa surgery, and 17 patients who did not have hydrocephalus were treated by elective posterior fossa surgery. Another 4 ETV were performed in the management of postoperative hydrocephalus.ResultsPreoperative ETV procedures were technically successful. One was complicated by intraventricular bleeding. The successful 19 preoperative ETV resolved intracranial hypertension before posterior fossa surgery in all cases. Three of these 19 patients developed postoperative hydrocephalus and were treated by VP shunt insertion after posterior fossa surgery. Out of the 4 ETV performed after posterior fossa surgery, only 2 were successful, both when the shunt malfunctioned.ConclusionsEndoscopic third ventriculostomy should be considered as an alternative procedure to ventriculo-peritoneal shunting and external ventricular draining for the emergency control of severe hydrocephalus caused by posterior fossa tumors, since it can quickly eliminate symptoms, and hence, can delay surgery scheduling if required. Even though ETV does not prevent postoperative hydrocephalus in all cases, it does protect against acute postoperative hydrocephalus due to cerebellar swelling. In addition, it eliminates the risks of cerebrospinal fluid (CSF) infection related to external drainage and minimizes the risk of overdrainage because it provides more physiological CSF drainage than the other procedures. Since postoperative hydrocephalus is very often physically obstructive, ETV should always be considered a possible treatment procedure.

Intracranial pressure monitoring and lumbar puncture after endoscopic third ventriculostomy in children.

OBJECTIVE:The aim of this study is to analyze changes in intracranial pressure (ICP) after endoscopic third ventriculostomy (ETV) performed in children affected by noncommunicating hydrocephalus. METHODS:ICP was continuously recorded for an average of 7 days in 64 children who underwent 68 ETVs for obstructive triventricular hydrocephalus of various etiology. In the first group (44 children), ETV was performed as the primary treatment; in the second group (20 children), the patients presented with shunt malfunction and underwent ETV and shunt removal. Three of the patients in the second group were reoperated for obstruction of the stoma: two were reoperated once and one was reoperated twice. RESULTS:ICP changes after ETV were not homogeneous and varied according to etiology: the highest values were observed in patients affected by posterior fossa tumors and the lowest values were seen in patients operated on during shunt malfunction and who had their shunt removed. After 31 procedures (45.6%), ICP remained normal (<20 mmHg) for the entire duration of the monitoring. After 37 procedures (54.5%), ICP was persistently high on Day 1 (mean, 29.7) and decreased very slowly in the subsequent days, remaining high for 2–9 days (mean, 4.5). After 20 of the 37 procedures with high postoperative ICP, patients presented symptoms of intracranial hypertension that resolved, in most of the cases, with one or two lumbar punctures. Lumbar puncture was noted to be effective in bringing about fast normalization of the ICP and resolution of the symptoms. In 13 patients (19.1%), ETV failed and a ventriculoperitoneal shunt was implanted. After four procedures, the stoma obstructed and the patients were treated, reopening the stoma. Postoperative ICP was not statistically significant higher in the patients in whom ETV failed. CONCLUSION:The high ICP observed in a group of patients in the early postoperative days is probably related to the slow permeation of the subarachnoid spaces by the cerebrospinal fluid flowing out of the third ventriculostomy. Management of intracranial hypertension after ETV remains a matter of controversy. The role of the lumbar puncture in the faster normalization of the ICP is examined in this article. By increasing the compliance and the buffering capacities of the spinal subarachnoid spaces, it probably decreases the cerebrospinal fluid outflow resistance from the ventricular system, facilitating the decrease of the ventricular volume and allowing faster permeation of the intracranial subarachnoid spaces. High postoperative ICP can account for persistent symptoms of intracranial hypertension and ventricular dilatation on computed tomographic scans after third ventriculostomy. A cycle of one to three lumbar punctures should always be performed in patients who remain symptomatic and who show increasing ventricular dilatation after ETV, before ETV is assumed to have failed and an extracranial cerebrospinal fluid shunt is implanted.

Hydrocephalus in aqueductal stenosis.

IntroductionThe sylvian aqueduct is the most common site of intraventricular blockage of the cerebro-spinal fluid. Clinical aspects, neuroradiological appearance, and treatment of hydrocephalus secondary to aqueductal stenosis are specific.MethodsAn extensive literature review concerning etiologic, pathogenetic, clinical, and neuroradiological aspects has been performed. Therapeutic options, prognosis, and intellectual outcome are also reviewed.ConclusionThe correct interpretation of the modern neuroradiologic techniques may help in selecting adequate treatment between the two main options (third ventriculostomy or shunting). In the last decades, endoscopic third ventriculostomy has become the first-line treatment of aqueductal stenosis; however, some issues, such as the cause of failures in well selected patients, long-term outcome in infant treated with ETV, and effect of persistent ventriculomegaly on neuropsychological developmental, remain unanswered.

Hydrocephalus in Dandy–Walker malformation

IntroductionEven if the first description of Dandy–Walker dates back 1887, difficulty in the establishment of correct diagnosis, especially concerning differential diagnosis with other types of posterior fossa CSF collection, still persists. Further confusion is added by the inclusion, in some classification, of different malformations with different prognosis and therapeutic strategy under the same label of “Dandy–Walker”.MethodsAn extensive literature review concerning embryologic, etiologic, pathogenetic, clinical and neuroradiological aspects has been performed. Therapeutic options, prognosis and intellectual outcome are also reviewed.ConclusionThe correct interpretation of the modern neuroradiologic techniques, including CSF flow MR imaging, may help in identifying a “real” Dandy–Walker malformation. Among therapeutical strategies, single shunting (ventriculo-peritoneal or cyst-peritoneal shunts) appears effective in the control of both ventricle and cyst size. Endoscopic third ventriculostomy may be considered an acceptable alternative, especially in older children, with the aim to reduce the shunt-related problems. Prognosis and intellectual outcome mostly depend on the presence of associated malformations, the degree of vermian malformation and the adequate control of hydrocephalus.

Interhemispheric and quadrigeminal cysts.

BACKGROUND Interhemispheric and quadrigeminal cysts are rare lesions, similar in their propensity to present in young babies and to be associated with other central nervous system malformations, such as corpus callosum agenesia, holoprosencephaly, encephalocele, and neuronal heterotopias. Recently endoscopy has become increasingly popular in the treatment of arachnoid cysts, but experience with cysts located in the interhemispheric fissure and in the quadrigeminal cistern is limited. METHODS This study reviews the specific anatomy of interhemispheric and quadrigeminal cysts and their relationship with the ventricular system and subarachnoid cisterns to select the most appropriated treatment. It also reviews the literature on endoscopic treatment of interhemispheric and quadrigeminal cysts. RESULTS Interhemispheric and quadrigeminal cysts are not homogeneous, they have different extensions toward surrounding regions. In most cases it is presented as an area of contiguity between the cyst and ventricular system and/or subarachnoid cisterns, making endoscopic treatment feasible. The success rate for endoscopic treatment is not different from that reported in large series of arachnoid cysts elsewhere. CONCLUSIONS Endoscopic treatment should be considered the first-line option in the treatment of such lesions, even if some complications, such as subdural collections due to thinness of the cerebral mantle or subcutaneous CSF collections due to multifactorial associated hydrocephalus, must be expected.

Lhermitte–Duclos (Section Rare Tumors)

Lhermitte–Duclos disease (LDD), also known as dysplastic cerebellar gangliocytoma, is a rare mass lesion of the cerebellum. It was first described in 1920. The lesion may be part of a syndrome and associated with congenital malformations, such as megalencephaly, hemihypertrophy, partial gigantism, and polydactyly. Its nature is controversial, and the debate whether it represents a tumor, malformation, or hamartoma is still open.