Neuroendoscopic surgery for unilateral hydrocephalus due to inflammatory obstruction of the Monro foramen

Article Arq Neuropsiquiatr 2011;69(2-A):227-231 Neuroendoscopic surgery for unilateral hydrocephalus due to inflammatory obstruction of the Monro foramen Francisco A. Vaz-Guimarães Filho1, Clauder O. Ramalho2, Ítalo C. Suriano3, Samuel T. Zymberg4, Sérgio Cavalheiro4 ABSTRACT Objective: Unilateral hydrocephalus (UH) is characterized by enlargement of just one lateral ventricle. In this paper, the authors will demonstrate their experiences in the neuroendoscopic management of this uncommon type of hydrocephalus. Method: The authors retrospectively reviewed a serie of almost 800 neuroendoscopic procedures performed from September 1995 to July 2010 and selected seven adult patients with UH. Clinical and radiological charts were reviewed and analyzed. Results: Six patients had intraventricular neurocysticercosis and one patient had congenital stenosis of the foramen of Monro. Headaches were the most common symptom. A septostomy restored cerebrospinal fluid circulation. During follow-up period (65.5 months, range 3-109) no patient has presented clinical recurrence as well as no severe complications have been observed. Conclusion: UH is a rare condition. A successful treatment can be accomplished through a neuroendoscopic approach avoiding the use of ventricular shunts. Key words: foramen of Monro, unilateral hydrocephalus, neuroendoscopy, neuro cysticercosis. Cirurgia neuroendoscópica para tratamento da hidrocefalia unilateral secundária à obstrução inflamatória do forame de Monro Correspondence Francisco de Assis Vaz-Guimarães Filho Rua Doutor Diogo de Faria 1202 / cj. 31 04037-004 São Paulo SP - Brasil E-mail: RESUMO Objetivo: Hidrocefalia unilateral (HU) é caracterizada pelo alargamento de apenas um dos ventrículos laterais. Neste estudo, os autores demonstraram sua experiência no manejo deste tipo incomum de hidrocefalia. Método: Foram revisados, de uma série de quase 800 cirurgias neuroendoscópicas realizadas entre Setembro de 1995 e Julho de 2010, sete pacientes adultos com diagnóstico de HU. Dados clínicos e radiológicos foram analisados. Resultados: Seis pacientes tinham neurocisticercose intraventricular e um apresentava uma estenose congênita do forame de Monro. Cefaléia foi o sintoma clínico mais comum. Uma septostomia restabeleceu o fluxo liquórico. Durante o seguimento (65,5 meses, de 3-109), nenhum paciente apresentou recorrência clínica assim como nenhuma complicação grave foi observada. Conclusão: HU é uma condição rara. O tratamento satisfatório pode ser alcançado por meio de uma abordagem neuroendoscópica evitando, desta maneira, o uso de sistemas de derivação ventricular. Palavras-chave: forame de Monro, hidrocefalia unilateral, neuroendoscopia, neuro cisticercose. Received 29 June 2010 Received in final form 4 November 2010 Accepted 12 November 2010 Department of Neurology and Neurosurgery, Division of Neurosurgery, Federal University of São Paulo, São Paulo SP, Brazil: 1 MD, Assistant Neurosurgeon; 2MD, Resident in Neurosurgery; 3MSc, Staff Neurosurgeon; 4PhD, Professor of Neurosurgery. 227 Neuroendoscopic surgery: unilateral hydrocephalus Vaz-Guimarães Filho et al. Arq Neuropsiquiatr 2011;69(2-A) Blockage of normal cerebrospinal fluid (CSF) pathways causing obstructive hydrocephalus is often a lifethreatening condition. Most cases present as acute intracranial hypertension syndrome. To date, neuroendoscopic management is considered the “gold-standard” treatment1. Different etiologies could be responsible for this blockage. Neoplastic, infectious, vascular and congenital diseases can interrupt the CSF flow at any point of the ventricular system1-3. By neuroendoscopic means, the neurosurgeon can create an “artificial” pathway that restores CSF circulation4. If the site of obstruction is located in the third or fourth ventricles, enlargement of both lateral ventricles will occur. Otherwise, if the blockage is located around one of the foramen of Monro, an enlargement of just one lateral ventricle will occur5-11. This condition is recognized as unilateral hydrocephalus (UH). The clinical manifestations are commonly mild or slowly progressive and the diagnosis is often delayed. Treatment of UH includes ventricular shunting8 and neuroendoscopic approach4,5,7 through fenestration of the septum pellucidum or foraminal plasty of the foramen of Monro12. In this paper, the authors will demonstrate their experience in the neuroendoscopic management of this uncommon type of hydrocephalus in adult patients and discuss relevant clinical and surgical data. METHOD In the Division of Neurosurgery of Federal University of São Paulo, almost 800 patients underwent neuroendoscopic surgery between September 1995 and July 2010. From this group, we identified seven adult patients (four females and three males, mean age 41 years, range 22-72 years) with the diagnosis of UH. Medical charts were reviewed and clinical data analyzed (Table 1). UH in pediatric patients was not included because, in the author’s opinion, the main etiologies (posthemorrhagic, congenital abnormalities) should be discussed in another specific study. All patients had radiologic evaluation with magnetic resonance imaging (MRI). Enlargement of one lateral ventricle confirmed the diagnosis of UH. At this point, special attention was directed to find out the cause of the ventriculomegaly. All patients underwent neuroendoscopic surgery. The entry point was determined by the side of the ventricular enlargement. Furthermore, this point was located 2 cm anterior to coronal suture and related with the external orbital line. This position could provide a more comfortable approach to the midline structures (foramen of Monro, septum pellucidum). After tapping ventricular cavity, a rigid 0-degree neuroendoscope was inserted and ventricular anatomy recognized by direct observation. The foramen of Monro and the septum pellucidum were carefully examined and the surgical decision (fenestration or plasty) made. Postoperative follow-up was accomplished with MRI and clinical evaluation. All patients signed an informed consent for this study. RESULTS Six patients had intraventricular neurocysticercosis and one patient had congenital stenosis of the foramen of Monro. Headaches were the most common clinical presentation (six patients) followed by vertigo (four patients) and papiledema (three patients). The time from initial clinical manifestations to diagnosis was 11 months (range 6-20 months). MRI studies showed unilateral ventricular enlargement with signs of increased pressure such as a shifting of the septum pellucidum and CSF periventricular transudation. In one patient with cysticercosis, the cyst was loose in the ventricular cavity and easily removed. On the other hand, one patient developed UH after medical treatment of neurocysticercosis. During surgical procedure, a thin membrane was identified in the region of the foramen of Monro leading to ventricular enlargement (Fig 1). A septostomy and a foraminal p (...truncated)