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Biomedical subjects

M Vloeberghs

Publications and source records attributed to M Vloeberghs.

At least 19 recordsLinked to original sources

A virtual reality surgery simulation of cutting and retraction in neurosurgery with force-feedback.

A virtual-reality surgical simulator aimed at neurosurgery is presented. The simulator utilises boundary element (BE) technology to develop real-time realistic deformable models of the brain. The simulator incorporates the simulation of surgical prodding, pulling and cutting. Advanced features include the separation the cut surfaces by retractors and post-cutting deformations. The experience of virtual surgery is enhanced by implementing 3D stereo-vision and the use of two hand-held force-feedback devices.

Neurosurgery↗

Rigid-body modelling of shaken baby syndrome.

Recent reassessment of the literature on the shaken baby syndrome (SBS) has revealed a lack of scientific evidence and understanding of all aspects of the syndrome. In particular, studies have been unable to clarify the mechanisms of injury, indicating that impact, rather than shaking alone, is necessary to cause the type of brain damage observed. Rigid-body modelling (RBM) was used to investigate the effect of neck stiffness on head motion and head-torso impacts as a possible mechanism of injury. Realistic shaking data obtained from an anthropometric test dummy (ATD) was used to simulate shaking. In each study injury levels for concussion were exceeded, though impact-type characteristics were required to do so in the neck stiffness study. Levels for the type of injury associated with the syndrome were not exceeded. It is unlikely that further gross biomechanical investigation of the syndrome will be able to significantly contribute to the understanding of SBS. Current injury criteria are based on high-energy, single-impact studies. Since this is not the type of loading in SBS it is suggested that their application here is inappropriate and that future studies should focus on injury mechanisms in low-energy cyclic loading.

Acceleration↗

The role of neuroendoscopy in the management of brain tumours.

Neuroendoscopy is increasingly used in the management of brain tumours and tumour related hydrocephalus and this study reviews the efficacy of neuroendoscopic interventions in this unit in patients with brain tumours. A series of 87 neuroendoscopic operations carried out in 77 patients with brain tumours over a 6-year period is reported. The age range of the patients was from 5 months to 70 years (median 13 years). In 56 cases (64%) presentation was with a newly-diagnosed tumour and hydrocephalus. The majority of the remaining patients had varying degrees of worsening hydrocephalus on the background of a previously diagnosed tumour. Neuroendoscopic third ventriculostomy (NTV) was successful in relieving hydrocephalus in the short term in 63/66 cases (95%) and in the longer term in 55/66 cases (83%). Neuroendoscopic tumour biopsies were successful in providing a tissue diagnosis in 17/28 cases (61%) and four extensive and three partial resections of tumour were carried out. There were two deaths within 30 days of the procedure with only one of these, secondary to intraventricular haemorrhage, directly related to neuroendoscopy. Few significant complications were noted otherwise. For selected intraventricular and paraventricular tumours neuroendoscopy offers the opportunity to combine relief of hydrocephalus with tumour biopsy and sampling of CSF in a single procedure.

Adolescent↗

Changes in third ventricular size with neuroendoscopic third ventriculostomy: a blinded study.

The objective was to study the relation between changes in cerebral ventricular size and clinical outcome after neuroendoscopic third ventriculostomy (NTV) in both primary (no previous surgery) and secondary (previous CSF diversion for hydrocephalus) NTV. Changes in ventricular size were related to the need for further surgery for CSF diversion. A blinded retrospective study of the pre-NTV and post-NTV sizes of the ventricles in an unselected series of patients undergoing this procedure was done. A decrease in third ventricular size was seen in significantly more patients in the primary group than in the secondary group. Median change in third ventricle width for those who did not require further CSF diversion was significantly greater than those with no clinical benefit (p=0.01). Positive predictive power for successful outcome was highest for measures of the third ventricle; 73% and 68% for third ventricle width and height respectively, 88% for anterior to posterior commissure distance. In conclusion, third ventricular size reduces after NTV. The use of such a change as an arbiter of success in this procedure is questionable as clinically successful cases can have no change in ventricular size. It is considered that clinical outcome is the most important guide to success or failure as reduction in ventricular size is by no means guaranteed. Radiological outcomes alone may be misleading and reliance on them should be avoided.

Adolescent↗

Neuroendoscopic third ventriculostomy in dysmorphic brains.

Neuroendoscopic third ventriculostomy (NTV) has superseded shunting as the treatment of choice in non-communicating hydrocephalus. Intracranial developmental anomalies have been considered to be relative contraindications for this procedure. We present one patient with a Dandy-Walker malformation and another with septo-optic dysplasia who presented with hydrocephalus. An NTV was performed successfully in both patients using a flexible neuroendoscope and utilising transendoscopic Doppler ultrasound to ensure a safe target area for ventriculostomy.

Brain↗

The effectiveness of neuroendoscopic interventions in children with brain tumours.

OBJECT: The purpose of this study was to review the efficacy of neuroendoscopic interventions in children with brain tumours and tumour-related hydrocephalus. METHODS: In all, 61 consecutive neuroendoscopic operations carried out in 53 children with brain tumours over a 6-year period were reviewed. The patients ranged in age from 5 months to 18 years (median 9 years). Forty of 61 presentations were with a newly diagnosed tumour and hydrocephalus - the remainder predominantly had a known tumour and worsening hydrocephalus. CONCLUSIONS: Neuroendoscopic third ventriculostomy (NTV) successfully relieved hydrocephalus in the short term in 45 of 47 cases and in the longer term in 39 of 47 cases. Neuroendoscopic biopsy provided definitive tissue diagnosis in 10 of 16 cases and 5 tumours were resected. There was 1 postoperative death, which not directly related to the neuroendoscopy and few significant complications otherwise. Neuroendoscopic methods allow effective immediate and longer term control of hydrocephalus as well as the opportunity for CSF sampling and tumour biopsy in selected cases.

Adolescent↗

Neuroendoscopic third ventriculostomy for hydrocephalus in adults: report of a single unit's experience with 63 cases.

BACKGROUND: Neuroendoscopic third ventriculostomy (NTV) is becoming a first line treatment for hydrocephalus in this center. Its use in a consecutive series of adults is reported. METHOD: Initially a retrospective data collection after 7 months becoming prospective studying all patients who underwent NTV in this center. The adults (17 years or older) have been studied. RESULTS: Sixty-three patients met the criteria for inclusion: 38 male, 25 female. Mean age at first NTV 37.5 years. There was an 80% success rate (i.e., no further therapy for the hydrocephalus required). Follow-up was for a mean of 3.1 years. The largest subgroup were patients with third ventricular tumours (35%), of whom 86% were successfully treated. Mean time to failure for the whole series was 8.5 months (range immediate--30 months). Complications occurred in 17.5%; those deemed serious in 11%. There were three deaths (4.7%) within 30 days of the procedure. There were six other deaths during follow-up, five because of tumour progression and one because of pneumonia. CONCLUSIONS: This procedure lends itself to the treatment of hydrocephalus in adults and appears to be more successful than in young children. It is efficacious in both previously shunted and non shunted patients. It is now the first-line treatment for noncommunicating hydrocephalus in this center and also for patients with shunt failure who are anatomically suitable, having cerebrospinal fluid spaces large enough to admit the endoscope. The complication and mortality rates compare favorably with those for shunts.

Adolescent↗

The fate of the cerebrospinal fluid after neuroendoscopic third ventriculostomy.

This paper describes the case of a 9-year-old girl with a posterior thalamic/pineal region lesion and secondary obstructive hydrocephalus. The hydrocephalus was treated by neuroendoscopic third ventriculostomy (NTV), and she underwent simultaneous transendoscopic biopsy. The tumour biopsy was haemorrhagic, but the bleeding settled with constant irrigation. The patient remained neurologically unchanged, but subsequent imaging revealed an asymptomatic thoracolumbar spinal subdural haematoma thought to be due to blood flowing out through the NTV into the subdural space. This demonstrates the subdural location of the cerebrospinal fluid after NTV.

Biopsy↗

Improved safety of neuroendoscopic third ventriculostomy by using an operative Doppler ultrasound probe. Technical note.

In this paper the authors describe the use of a Doppler device, originally built for intravascular use, that is passed through a flexible neuroendoscope during a neuroendoscopic third ventriculostomy (NTV) procedure to treat for hydrocephalus. There was no morbidity associated with the use of this Doppler probe, and the procedure was not significantly lengthened. The Doppler probe was very accurate in locating the position of the basilar artery tip and assured the safety of NTV.

Journal Article↗

Flexible neuroendoscopic treatment of suprasellar arachnoid cysts.

Endoscopic treatment of suprasellar arachnoid cysts is now the treatment of choice. By marsupializing the roof of the cyst the condition can be cured. The perceived necessity to open both the roof and the floor is called into question by this paper. Three cases of suprasellar arachnoid cyst are described all of which have had successful marsupialisation of the cysts by flexible neuroendoscopy Flexible neuroendoscopic marsupialization of the cyst by widely opening the cyst roof only is described. This is compared with the other techniques, and also the endoscopic technique involving opening both the roof and the floor of the cyst, a more difficult and potentially dangerous method. Successful treatment of this condition is achieved by marsupialization of only the roof of the cyst. This is a much safer procedure, and has resulted in a resolution of signs and symptoms in the cases described followed-up between 24 and 28 months from the procedure.

Arachnoid Cysts↗

Sinus pericranii. Report of a case and review of the literature.

Sinus pericranii is an unusual anomaly of venous drainage from intracranial to extracranial systems via the diploë of the skull. A case and its management are presented. The aetiology, various options regarding treatment and their indications are discussed, including various surgical techniques and interventional radiology.

Abnormalities, Multiple↗

Soft tissue rapid prototyping in neurosurgery.

As part of our research into the fluid hydrodynamics of the human ventricular system, a fused deposition model of the human ventricular system was made using magnetic resonance imaging (MRI) data. This article describes the manufacturing of a positive cast of the ventricles as a first step in the construction of a hollow model. After decryption of the original MRI file (ACR-Nema format), the MRI slices were reassembled semiautomatically and a rapid prototyping station produced a resin model. Because of its ease and speed, this method harbors great potential for teaching purposes, research, and preoperative planning in complex three-dimensional soft tissue targets.

Cerebral Ventricles↗

Liliequist's membrane in minimally invasive endoscopic neurosurgery.

Liliequist's membrane, an arachnoid condensation extending from the upper border of the dorsum sellae to the anterior edge of the mammillary bodies and formerly a relatively insignificant structure, has been found to be extremely important in the neuroendoscopic management of hydrocephalus. Failure to open this membrane can lead to the failure of third ventriculostomies.

Arachnoid↗

Ruptured fusiform cerebral aneurysm in a neonate.

An 11-day-old male infant presented with subarachnoid and intraventricular haemorrhage caused by a ruptured intracranial aneurysm. Magnetic resonance (MR) angiogram and digital subtraction angiography (DSA) revealed a fusiform aneurysm 10 mm in diameter supplied by the proximal segment of the anterior cerebral artery (A1), with both distal segments (A2) arising from the aneurysm. The right A1 was aplastic. There have been 13 previous case reports of neonatal cerebral artery aneurysms, but only 1 of these has been fusiform. None of the earlier reports has mentioned dysplastic segments or other anomalies of the circle of Willis.

Aneurysm, Ruptured↗

Neuroendoscopy in the premature population.

The population born prematurely is particularly prone to hydrocephalus. Shunting techniques, whilst still the gold standard, have considerable failure rates and contribute significant morbidity and mortality. The role of neuroendoscopic techniques in the treatment of such patients is explored, and a series of 19 patients born prematurely and operated on neuroendoscopically before their 1st birthdays is described.

Cerebral Hemorrhage↗