Search PubMed⌕ Search

Biomedical subjects

D Le Gars

Publications and source records attributed to D Le Gars.

At least 19 recordsLinked to original sources
PubMed2006

[Terminovertebral aneurysm arising from basilar artery fenestration].

A case of ruptured middle saccular aneurysm arising from basilar artery fenestration is reported. Defects of the medial wall at the junctures of the fenestrated segments explain the association between vertebrobasilar aneurysms and basilar artery fenestration. A 47 year-old woman had a perimesencephalic subarachnoid hemorrhage. Immediate angiography revealed a ventral vertebrobasilar aneurysm and an endovascular coil occlusion was performed. Embryological development, pathogenesis and therapeutic difficulties are discussed.

Adult↗
PubMed2006

[Cerebrospinal fluid flow imaging in the meningeal hemorrhage].

BACKGROUND AND PURPOSES: Cerebrospinal fluid (CSF) flow oscillations are synchronized with cerebral blood flow and are also involved in the control of variations of intracranial pressure during the cardiac cycle. The aim of this study was to investigate the possible alterations of CSF flow dynamics during the acute phase of meningeal hemorrhage (MH). METHODS: Eleven patients with MH confirmed by computed tomography (CT) scan were examined by MR imaging, which comprised morphological sequences and flow dynamic sequences for quantification of CSF oscillations and cerebral blood flow rates. CSF oscillations were recorded at the cerebral aqueduct and C2-C3 subarachnoid space (SAS), where a vascular sequence was also performed to quantify artery blood flow. These results were compared to oscillations of a population of 44 control subjects and a difference of at least two standard deviation was used to define a hyperdynamic or hypodynamic appearance of CSF flow. Dilatation of the ventricular system was determined on radiographs by two neuroradiologists and a neurosurgeon. RESULTS: Only four patients presented normal ventricular CSF flow, one patient presented hypodynamic flow and five patients presented hyperdynamic flow. Five patients had normal cervical CSF flow and five patients presented hyperdynamic flow. The two patients with ventricular dilatation both presented hyperdynamic ventricular CSF flow associated with normal cervical CSF flow. One patient was excluded. CONCLUSION: Abnormal CSF flow dynamics were shown suggesting the hypothesis that bleeding increases intracranial volume and induces a reduction of cerebral compliance and an increase of intracranial pressure. The increased oscillations in the ventricular system would therefore predispose to dilatation.

Adult↗
PubMed2006

Lhermitte-Duclos disease and Cowden's syndrome. Report of two cases.

OBJECTIVE AND IMPORTANCE: Lhermitte-Duclos disease, or dysplastic cerebellar gangliocytoma is a rare entity characterized by a hamartomatous lesion in the posterior fossa. Cowden's syndrome, or hamartoma-neoplasia syndrome is a rare underdiagnosed autosomal dominant genodermatosis with high incidence of malignant tumors. Several recent reports suggest that Lhermitte-Duclos disease may be a component of Cowden's syndrome. CLINICAL PRESENTATION: We report two cases of Lhermitte-Duclos and Cowden disease occurring in adult patients. A 40-year-old woman had symptoms of raised intracranial pressure and macrocephaly. She displayed the stigmata of fibrocystic breast disease, thyroid goitre. Clinical examination showed mucocutaneous lesions. Her mother, brother and uncle had manifestations of Cowden's disease. An asymptomatic 38-year-old male had bilateral optic nerve drusen related to a cerebellar neoplasm. He exhibited manifestations of Cowden's syndrome and his familial history confirmed this hypothesis. INTERVENTION: The first patient was operated on for Lhermitte-Duclos disease. A conservative strategy was performed for the second patient and the clinical and imaging follow-ups were uneventful over 5 years. CONCLUSION: We stress the possibility that Lhermitte-Duclos and Cowden disease might be a peculiar form of phakomatosis. A conservative strategy can be chosen without neurological signs because of slow tumor growth. However, these patients should be carefully examined and followed up because of the risk of future malignancy.

Adult↗
PubMed2006

[MRI localization of paraclinoid carotid aneurysms].

AIM: The distal dural ring plane (DDRP) separates the intracavernous from the supracavernous paraclinoid internal carotid artery. The purpose of this MRI protocol is to evaluate the position of this plane for the characterization of paraclinoid aneurysms. METHOD: The protocol uses a T2 weighted sequence in two orthogonal planes (diaphragmatic and carotid planes) and two correlation lines in each plane. These lines pass through anatomo-radiological reference points correlated with the medio-lateral and antero-posterior margins of the DDRP. We use the intersection angle of these lines as the inferior radiological limit of the DDRP curve. RESULTS: An aneurysm located above this angle is supracavernous; an aneurysm located below this angle is intracavernous; an aneurysm crossing this angle is transitional. CONCLUSION: In difficult cases, this MRI protocol could help better characterize the exact localization of paraclinoid aneurysms on both sides of the cavernous sinus roof.

Carotid Artery Diseases↗
PubMed2006

Value of phase contrast magnetic resonance imaging for investigation of cerebral hydrodynamics.

OBJECTIVE: Phase Contrast Magnetic Resonance Imaging (PCMRI) is a noninvasive technique that can be used to quantify variations of flow during the cardiac cycle. PCMRI allows investigations of blood flow dynamics in the main arteries and veins of the brain but also the dynamics of cerebrospinal fluid. These cerebral flow investigations provide a description of the regulation mechanisms of intracranial pressure during the cardiac cycle. The objective of this paper is to describe the contribution of this technique in diseases related to disorders of cerebral hydrodynamics in the light of 5 clinical cases. METHOD: Flow measurements were performed using PCMRI sequences on a 1.5 Tesla MR imager in 4 patients with symptomatic ventricular dilation and 1 patient with a syringomyelic cavity. RESULTS: Flow quantification in these 5 patients, representative of the diseases mainly concerned by cerebral hydrodynamics, is useful to guide the indication for ventricular shunting in patients with hydrocephalus, to demonstrate obstruction of the cerebral aqueduct, to demonstrate recirculation of ventricular CSF after ventriculostomy and to characterize the dynamic features of CSF inside a spinal cavity. CONCLUSION: PCMRI, now available to neurosurgeons, is complementary to morphological MR and provides quantitative information on cerebral hydrodynamics. This information is mainly used to confirm alteration of CSF flow in the cerebral and spinal compartments. PCMRI is also a functional tool to better understand the pathophysiology of hydrocephalus and syringomyelia.

Adult↗
PubMed2005

[Anatomical basis of the extraspinal cord compression].

Knowledge of anatomical landmarks of the spinal cord within the vertebral foramen is essential to understand the pathogenesis of spinal cord compression by tumor growth. The spinal cord can spread in the intervertebral foramen, the epidural space, the vertebral body, and the posterior neural arch. The morphology of the spinal cord, the relations of the spinal roots with the vertebrae, the principal fiber tracts, the spinal membranes, and the arterial and venous distribution are described in order to explain and analyze signs and disorders caused by the most frequent tumors involved in spinal cord compression.

Humans↗
PubMed2005

[Duplication of the inferior vena cava: anatomical dissection and clinical implications].

The duplication of the inferior vena cava is often incidentally discovered during radiological studies. The presence of this anomaly can be mistaken for retroperitoneal adenopathy. Its knowledge allows to avoid hemorrhagic complications during retroperitoneal surgery. An anatomical dissection of a duplication of the inferior vena cava is presented. Embryogenesis and variations are described. Radiological and clinical implications are discussed.

Aorta, Abdominal↗
PubMed2005

Melanocytic schwannomas. Report of three cases.

OBJECTIVE AND IMPORTANCE: Melanocytic tumors are rare. The literature reports less than 40 cases and suggests that they behave aggressively, can recur and progress to malignancy. CLINICAL PRESENTATION: We report three patients with melanocytic schwannomas located in the cervical spine, in the thoracic spine and in the lumbar spine. In the two first cases, these symptoms were a spinal cord compression whereas the last patient presented symptoms of cruralgy. IMAGING: MRI always showed an extramedullary intradural tumor arising from the root destroying the intervertebral foramen. INTERVENTION: The patients underwent laminectomy and the excision was complete. Immunohistochemical stains were positive to S100 and HMB45 antibodies. The evolution was unfavourable for two patients with local recurrence and leptomeningeal metastasis. CONCLUSION: These three cases demonstrate that melanocytic schwannomas have a guarded prognosis because of their metastatic potential, especially for young people.

Adult↗
PubMed2004

[Aneurysmal rupture during embolization with Guglielmi detachable coils].

OBJECTIVE: The purpose of this study is to determinate the frequency, causes, management and outcome of aneurysmal rupture occurring during embolization. We present our experience with this severe and feared complication. METHODS: We retrospectively reviewed 314 acute cerebral aneurysms that were treated with endovascular coiling. These patients were identified and the management and outcomes were recorded. The literature was reviewed. RESULTS: Six patients had an intraprocedural aneurysmal rupture. This complication occurred sporadically. Prevalence was 1.9%. Of these six, four were women and two were men. The mean age was 68 years (range: 43-74 years). Four aneurysms were located in the anterior circulation and two in the posterior circulation. Perforation occurred during microcatheterization of the aneurysm in one case and during coil deposition in five cases. In these five patients, aneurysmal rupture resulted from detachment of the first coil in three patients and detachment of the third and last coil in two patients. Hemodynamic changes were noted for one patient. The Glasgow Outcome Scale score at last follow-up examination was 1 in three patients and 3 in one patient (fair recovery). Mortality was 33% and morbidity was 16.7%. CONCLUSION: Aneurysmal perforation during embolization is a rare event (1.8 to 4.4%). When perforation is recognized, embolization can be completed immediately with further coil deposition and reversal of anticoagulation therapy.

Adult↗
PubMed2004

[Contribution of percutaneous acrylic vertebroplasty for tumor-related spinal cord compression].

We report two cases of spinal cord compression due to vertebral hemangioma in the first patient and myeloma in the other. Vertebroplasty was performed in both patients, combined with surgery for the first and radiotherapy for the second. Postprocedural pain decreased within 24 hours. Indications for percutaneous vertebroplasty are limited to aggressive vertebral hemangiomas, malignant spinal tumors including metastasis, multiple myeloma and solitary bone plasmocytoma. Vertebroplasty consolidates the vertebral body and reduces the risk of hemorrhage. It allows provides a rapid analgesic effect, radicullomedullary decompression associated with neurosurgery, spinal stabilization and can restrict progression of vascular malformations or tumors. Incidents and complications appear to be rare.

Aged↗
PubMed2003

The dural crossing of the vertebral artery.

The aim of this study was to present the anatomic and macroscopic aspects of the vertebral artery at the level of the dural crossing. Twenty vertebral arteries in 10 cadavers were dissected. The preparations were photographed and all the samples at the level of the dural crossing were submitted to a histologic study. Macroscopic results allow specification of the relationships between the dural crossing of the vertebral artery and the nervous elements (C1 and C2 nerves, mixed nerves), the vascular elements (postero-inferior cerebellar artery), the dural sheath and the first two dentate ligament tips. Microscopic results show the intricate relationship of the different layers of the vertebral artery with the dura at its crossing. Dural fibers reinforce the adventitial fibers not only by continuing them in their contact, much as the pages of a book, but also by being encrusted into the adventitia up to the tunica media, thus creating a very efficient mooring system. This work provides some information for an understanding of the symptoms induced by foramen magnum meningiomas and the onset of clinical signs after the surgical excision of these tumors. It also explains why dissections of the suboccipital segment of the vertebral artery stop at the level of the dural crossing, and never spread towards the intracranial segment.

Dura Mater↗
PubMed2003

Postoperative bilateral vertebral artery dissection: a case report.

With the improvement of medical imaging and surgical techniques, surgery on cervical vertebral is more frequent. Some cases of complications of this type of surgery have been described. We report a case of postoperative bilateral vertebral artery dissection. It concerns a 58 year-old woman who suffered from a left cervico-brachial C6 neuralgia with paresthesiae of the thumb. She underwent discectomy at C5-C6 and C6-C7 followed by setting up intersomatic cages. In subsequent days, an irreversible coma developed. Supra-aortic echographic study revealed bilateral vertebral artery thrombosis. CT scan revealed ischemic lesions of the brain stem and cerebellum. Cerebral death was declared five days after the operation. Autopsy was performed to determine whether death was the consequence of the intervention. The cause of death was determined to be ischemic brain injury of the brain stem and cerebellum resulting from bilateral traumatic occlusion of the vertebral arteries caused by the surgery.

Journal Article↗
PubMed2003

[Combined transfacial and neurosurgical approach for the treatment of ethmoid cancers].

OBJECTIVES: The purpose of this work was to examine the indications for the combined transfacial and neurosurgical approach to ethmoid cancers. PATIENTS AND METHODS: Fifteen patients with ethmoid cancers underwent surgery via the combined approach between 1990 and 2000 at the Amiens University Hospital. The transfacial approach alone was reserved for elderly patients. RESULTS: The histological diagnosis was adenocarcinoma in 10 patients. There was one postoperative death. Mean follow-up was 45 months (range 3 - 129). Six patients died from local or metastatic recurrence. At last follow-up eight patients were disease free, two had local or metastatic recurrence. CONCLUSION: We compared systematic use of the combined approach for curative surgery with surgical strategies adopted by other teams. The combined approach is indicated for T3 or T4 tumors and for all other tumors with a posterior or superior extension. Anterior and unilateral tumors may be treated with the transfacial access alone. Limited tumors without extension to the orbit or cribiform plate may be managed endoscopically. The role of histological diagnosis and the choice of the surgical approach remain to be evaluated.

Adenocarcinoma↗
PubMed2003

[Transarticular atlanto-axial screw fixation for treatment of C1-C2 instability].

Posterior transarticular screw fixation of the C1-C2 complex has become an accepted method of arthrodesis for patients requiring posterior C1-C2 fusion. Since 2000, four patients (2 males and 2 females) were treated with this surgical approach for management of atlantoaxial instability, including odontoid fracture with unilateral C1-C2 luxation, odontoid pseudarthrosis, complex congenital malformation of the craniovertebral junction and rheumatoid arthritis. All patients underwent stabilization with 2 transarticular C1-C2 screws, without any posterior interspinous graft. Patients were maintained in a rigid cervical orthesis 3 months postoperatively. Results were good, without any complication, after a short mean follow-up (8 months). Technical aspects of the technique are reported, The risk of screw malpositioning and vertebral artery or neural injury is minimal and can be lowered by using preoperative CT scan and MRI, and by using intraoperative fluoroscopy. Transarticular C1-C2 screw fixation proves to be a major surgical approach for treatment of atlantoaxial instability.

Aged↗
PubMed2002

Three-dimensional imaging of the petrous bone for the middle fossa approach to the internal acoustic meatus: an experimental study.

The goal of this study was to highlight the feasibility of creating three-dimensional (3D) pictures of the petrous bone from a routine CT examination which can be used for a middle fossa approach to the internal acoustic meatus, in order to secure this operation. The surgical aim is to reach the roof of the internal acoustic meatus directly without injuring the adjacent functional structures of the petrous bone. Two heads of embalmed cadavers were scanned every millimeter with a slice thickness of 1 mm centered on the petrous bones. The horizontal reference was the Frankfurt line and the frontal and sagittal planes were perpendicular to this line. This method is similar to routine examinations for surgical patients. The pictures were first loaded on an optical disk, then into a computer (Silicon Graphics System). Amira software was used to create 3D pictures. The anatomy of the temporal bone could easily be identified, notably the surgical landmarks of the middle fossa approach. Three-dimensional computer-assisted imaging can reveal the anatomy of the petrous bone in a realistic view. The main anatomic structures for a middle fossa approach can be recognized easily. This realistic view may be very useful for surgeons, and 3D images deserve to be developed further.

Head↗
PubMed2000

[Introduction and history of surgery of the third ventricle].

In this annual report of the Société de Neurochirurgie de Langue Française, the authors reviewed in a retrospective study 262 cases of tumors exclusively located in the third ventricle (thalamic, chiasmatic and pineal tumors were excluded). Modern neuroradiology easily discloses these lesions, and therapeutic management represents the main challenge : most of the patients present with few symptoms, and even in some cases the lesions are diagnosed fortuitously. Neuropsychological assessment appears necessary to evaluate the long-term outcome of the patients : unfortunately few cases in this series were informative for these data. Walter Dandy described the operative approach of these tumors in 1922, and he also reported the benefits of endoscopy. Almost 80 years later, technical advances such as CSF shunts, stereotaxis, neuronavigation have improved the results of the neurosurgical treatment of these deep-seated lesions.

History, 20th Century↗
PubMed2000

[Fundamental anatomy of the third ventricle].

Comparative anatomy of the third ventricle shows that this diencephalic cavity is present in most vertebrates. In humans, the roof of the third ventricle has thinned and most of its diverticles have disappeared. Human embryology underlines the development of hemispheric vesicles and interhemispheric commissures, and both of these structures progressively dissimulate the third ventricle deep within brain tissue. The anatomy of the third ventricle, particularly the roof of the ventricle and the interventricular foramen are described, with special references to their relationship with surrounding structures and vessels. The knowledge of these anatomical landmarks is essential to operative approaches to the third ventricle.

Humans↗