Membranous Structures Affecting the Success of Endoscopic Third Ventriculostomy in Adult Aqueductus Sylvii Stenosis

Abstract

Background: The purpose of the present study was to observe Liliequist's membrane (LM) and membranous structures located in the prepontine cistern via 3-Tesla magnetic resonance imaging (MRI) with 3D driven equilibrium radio frequency reset pulse (DRIVE) sequence and multiplanar reformat (MPR) images and to evaluate the success of endoscopic third ventriculostomy (ETV) by assessing these membranes in adult aqueduct stenosis.

Patients: 29 patients (17 female, 12 male) with primary aqueductus sylvii stenosis were included in the study. 19 patients were diagnosed as long-standing overt ventriculomegaly in adults (LOVA) and patients had severe ventriculomegaly, macrocephalus, and aqueduct stenosis on MR imaging. 10 patients were diagnosed as aqueduct stenosis presented with acute onset of hydrocephalus with symptoms of raised ICP. All patients in the study group were analyzed with conventional and cine MRI before and after treatment. We performed 3D DRIVE sequence and MPR at 3-T MR equipment to determine the membranous structures in 3 dimensions. We correlated the success of the procedure considering the preoperative, postoperative MRI and intraoperative images.

Results: 5 patients (26.3%) with LOVA and 2 patients (20%) with aqueduct stenosis, in total 7 patients (24.1%), did not respond to ETV. Cerebrospinal fluid (CSF) flow was blocked by membranous structures located in the prepontine cistern in 4 of 8 patients. In 2 patients, CSF through the stoma was blocked either by the LM or closed tuber cinerum. In 1 patient insufficient CSF flow was observed through the stoma and the LM accompanying prepontine membranes.Totally closed membranes were observed in the prepontine cistern in 5 patients (17.24%) according to the postoperative MRI. LM was verified in all patients intraoperatively that were also demonstrated in the preoperative MRI.

Conclusion: 3D sequences with MPR may help to observe not only the LM but also other membranes located through the prepontine cistern, which may be the reason of failed ETV.

Key words

endoscopic third ventriculostomy - aqueductal stenosis - Liliequist's membrane - hydrocephalus - MRI

References

• 1 Fushimi Y, Miki Y, Takahashi JA. et al . MR imaging of Liliequist's membrane.  Radiat Med. 2006;  24 85-90
• 2 Oi S, Sato O, Matsumoto S. Neurological and medico-social problems of spina bifida patients in adolescence and adulthood.  Childs Nerv Syst. 1996;  12 181-187
• 3 Oi S, Shimoda M, Shibata M. et al . Pathophysiology of long-standing overt ventriculomegaly in adults.  J Neurosurg. 2000;  92 933-940
• 4 Ciftci E, Anik Y, Arslan A. et al . Driven equilibrium (drive) MR imaging of the cranial nerves V–VIII: comparison with the T₂-weighted 3D TSE sequence.  Eur J Radiol. 2004;  51 234-240
• 5 Tisell M, Almstrom O, Stephensen H. et al . How effective is endoscopic third ventriculostomy in treating adult hydrocephalus caused by primary aqueductal stenosis?.  Neurosurgery. 2000;  46 104-110
• 6 Amini A, Schmidt RH. Endoscopic third ventriculostomy in a series of 36 adult patients.  Neurosurg Focus. 2005;  19 E9
• 7 Feng H, Huang G, Liao X. et al . Endoscopic third ventriculostomy in the management of obstructive hydrocephalus: an outcome analysis.  J Neurosurg. 2004;  100 626-633
• 8 Vanneste J, Hyman R. Non-tumoural aqueduct stenosis and normal pressure hydrocephalus in the elderly.  J Neurol Neurosurg Psychiatry. 1986;  49 529-535
• 9 Gangemi M, Mascari C, Maiuri F. et al . Long-term outcome of endoscopic third ventriculostomy in obstructive hydrocephalus.  Minim Invas Neurosurg. 2007;  50 265-269
• 10 Rekate HL, Nadkarni TD, Wallace D. The importance of the cortical subarachnoid space in understanding hydrocephalus.  J Neurosurg Pediatr. 2008;  2 1-11
• 11 Laitt RD, Mallucci CL, Jaspan T. et al . Constructive interference in steady-state 3D Fourier-transform MRI in the management of hydrocephalus and third ventriculostomy.  Neuroradiology. 1999;  41 117-123
• 12 Hoffmann KT, Lehmann TN, Baumann C. et al . CSF flow imaging in the management of third ventriculostomy with a reversed fast imaging with steady-state precession sequence.  Eur Radiol. 2003;  13 1432-1437
• 13 Peretta P, Cinalli G, Spennato P. et al . Long-term results of a second endoscopic third ventriculostomy in children: retrospective analysis of 40 cases.  Neurosurgery. 2009;  65 539-547
• 14 Singh I, Haris M, Husain M. et al . Role of endoscopic third ventriculostomy in patients with communicating hydrocephalus: an evaluation by MR ventriculography.  Neurosurg. 2008;  31 319-325
• 15 Bhadelia RA, Bogdan AR, Wolpert SM. Analysis of cerebrospinal fluid flow waveforms with gated phase-contrast MR velocity measurements.  AJNR. 1995;  16 389-400
• 16 Enzmann DR, Pelc NJ. Normal flow patterns of intracranial and spinal cerebrospinal fluid defined with phase-contrast cine MR.  Radiology. 1991;  178 467-474
• 17 Lev S, Bhadelia RA, Estin D. et al . Functional analysis of third ventriculostomy patency with phase-contrast MRI velocity measurements.  Neuroradiology. 1997;  39 175-179
• 18 Froelich SC, Abdel Aziz KM, Cohen PD. et al . Microsurgical and endoscopic anatomy of Liliequist's membrane: a complex and variable structure of the basal cisterns.  Neurosurgery. 2008;  63 (1 Suppl 1) ONS1-ONS8 discussion ONS8–ONS9
• 19 Buxton N, Vloeberghs M, Punt J. Liliequist's membrane in minimally invasive endoscopic neurosurgery.  Clin Anat. 1998;  11 187-190
• 20 Dincer A, Kohan S, Ozek MM. Is all “communicating” hydrocephalus really communicating? Prospective study on the value of 3D-constructive interference in steady state sequence at 3T.  AJNR Am J Neuroradiol. 2009;  30 1898-1906
• 21 Bargalló N, Olondo L, Garcia AI. et al . Functional analysis of third ventriculostomy patency by quantification of CSF stroke volume by using cine phase-contrast MR imaging.  AJNR Am J Neuroradiol. 2005;  26 2514-2521
• 22 Parkkola RK, Komu ME, Kotilainen EM. et al . Cerebrospinal fluid flow in patients with dilated ventricles studied with MR imaging.  Eur Radiol. 2000;  10 1442-1446
• 23 Stivaros SM, Sinclair D, Bromiley PA. et al . Endoscopic third ventriculostomy: predicting outcome with phase-contrast MR imaging.  Radiology. 2009;  252 825-832
• 24 Cinalli G, Sainte-Rose C, Chumas P. et al . Failure of third ventriculostomy in the treatment of aqueductal stenosis in children.  J Neurosurg. 1999;  90 448-454

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