Third ventriculostomy through the lamina terminalis for intracranial pressure monitoring after aneurysm surgery: technical note

Abstract

-Objective: A new ventriculostomy technique through the lamina terminalis is described. This technique is applied mainly during aneurysm surgery at the acute stage. Method: Thirteen patients were operated on intracranial aneurysms and, during the procedure, had the lamina terminalis fenestrated. A ventricular catheter was inserted into the third ventricule, left in place and connected to an external drainage system for further intracranial pressure (ICP) monitoring and/or cerebrospinal fluid (CSF) drainage. Results: ICP readings and CSF drainage were obtained in all cases. No complication was recorded. Conclusion: Third ventriculostomy through the lamina terminalis is a simple and easy technique that can be used as an alternative to conventional ventriculostomy. This procedure can be indicated in cases where the ventricule is not reached by means of another technique, and when the decision to perform ventriculostomy is made at the end of aneurysm surgery.KEY WORDS: cerebral aneurysm, ventricular drainage, third ventricle, intracranial pressure, operative technique.Terceiroventriculostomia via lamina terminalis para monitorização de pressão intracraniana após cirurgia de aneurisma: nota técnica RESUMO -Objetivo: Uma nova técnica de ventriculostomia através da lamina terminalis é descrita para utilização durante cirurgia de aneurisma na fase aguda. Método: Treze pacientes foram operados de aneurisma cerebral e, durante o procedimento, tiveram a lamina terminalis fenestrada. Um catéter ventricular foi inserido no terceiro ventrículo e conectado a um sistema de drenagem externa para monitorização da pressão intracraniana (PIC) e/ou drenagem de líquor (LCR). Resultados: A leitura da PIC e a drenagem do LCR foram obtidas em todos os casos. Não se evidenciaram complicações. Conclusão: A terceiroventriculostomia através da lamina terminalis é uma técnica simples e fácil, que pode ser usada como uma alternativa à ventriculostomia convencional. Esse procedimento pode ser indicado em casos em que as técnicas convencionais falham, ou quando a decisão de realizar a ventriculostomia é tomada ao final da cirurgia de aneurisma. PALAVRAS-CHAVE: aneurisma cerebral, drenagem ventricular, terceiro ventrículo, pressão intracraniana, técnica operatória.

Microscopic Stucture of the Lamina Terminalis: Implications for Microsurgical Third Ventriculostomy

“…In the course of massive intracisternal hemorrhages, distension of the LT due to disturbances of circulation and efflux of cerebrospinal fluid (CSF) is a frequent intraoperative finding. In these cases, an adjunct procedure to microsurgical LT opening is indicated to improve ventricular drainage and circulation of CSF and prevent the incidence of posthemorrhagic hydrocephalus [9,18] as well as to diminish the risk of vasospasm and ischemic complication [17].…”

“…Third ventriculostomy through incision of the LT has been found to be a less invasive and relatively safe procedure [4,5,9,17]. The LT is a thin translucent membrane, which constitutes the widest inferior part of the anterior wall of the third ventricle between the optic chiasm and anterior commissure.…”

“…The LT is a thin translucent membrane, which constitutes the widest inferior part of the anterior wall of the third ventricle between the optic chiasm and anterior commissure. The recommended optimal place to fenestrate the LT is the lower portion on the midline, immediately above and posterior to the optic chiasm [4,9,15]. Possible complications during this procedure can include a risk for intraoperative bleeding or postoperative endocrine disturbances due to the proximity of hypothalamic structures and the complexity of the branches of the anterior cerebral and anterior communicating artery, supplying hypothalamic, chiasmatic and subcallosal areas [12,16,20].…”