Search PubMed⌕ Search

Biomedical subjects

F Nataf

Publications and source records attributed to F Nataf.

At least 55 records · Page 3Linked to original sources
PubMed1999

Subcranial fronto-orbito-nasal approach for ethmoidal cancers surgical techniques and results.

BACKGROUND: The authors report their experience with the subfronto-orbito-nasal approach (SFON) for the treatment of 30 patients suffering from ethmoidal cancers over the past 3 years. The advantages and pitfalls of this technique are described and compared with other classic approaches. METHODS: Among 156 patients suffering from ethmoidal cancers and treated between January 1984 and January 1998, 30 patients were operated on using the SFON approach during the past 3 years. There were 27 males and 3 females, ranging in age from 15 to 77 years. Histologic composition of the lesions was as follows: 15 adenocarcinomas, 6 esthesioneuroblastomas, 3 melanomas, 2 epidermoid carcinomas, 1 nondifferentiated carcinoma, 1 neuroendocrine carcinoma, 1 villous carcinoma, and 1 cystic adenoid carcinoma (cylindroma). According to the authors' classification, 7% were T1, 6% T2, 22% T3, 38.5% T4a, and 26.5% T4b. All patients were operated on through a SFON approach, followed by removal of the tumor and reconstruction of the skull base with a pericranial flap. RESULTS: Since the mean follow-up was of short duration (12 months, ranging from 3 to 29 months), significant carcinologic results could not be obtained. However, a detailed analysis of the surgical procedure was performed. No patient died or had major complications related to the SFON approach. One cerebrospinal fluid (CSF) fistula and four oculomotricity dysfunctions were observed. Definitive anosmia was reported in all cases. CONCLUSION: The advantages of the procedure include a wide exposure of the anterior skull base through a limited approach, the possibility of modifying the approach according to the size and location of the lesion, total resection of tumors, simplified skull base reconstruction technique, and reduction of postoperative confusion and hospital stay.

Adolescent↗
PubMed1999

Radiosurgery of cerebral arteriovenous malformations: is an early angiogram needed?

BACKGROUND AND PURPOSE: Radiosurgical treatment of arteriovenous malformations (AVMs) has slow and progressive vasoocclusive effects. We sought to determine if early posttherapeutic angiography provides relevant information for the management of radiosurgically treated AVMs. METHODS: Between 1990 and 1993, the progress of 138 of 197 cerebral AVMs treated by linear accelerator (Linac) was regularly followed by angiographic study. On each posttherapeutic angiogram ("early," 6-18-month follow-up; "intermediate," 19-29-month-follow-up; and "late," > 30-month follow-up), the degree of reduction across the greatest diameter of the nidus and hemodynamic modifications were analyzed. Each cerebral AVM was qualitatively classified into one of the following categories after early angiographic study: 0%-reduced, 25%-reduced, 50%-reduced, 75%-reduced, and 100%-reduced or "complete obliteration." Vasoocclusive progress for each category was then studied over time. RESULTS: Three (10%) of the 30 0-25%-reduced, eight (38%) of 21 50%-reduced, and 27 (84%) of 32 75%-reduced cerebral AVMs showed complete obliteration after further follow-up. The three 0-25%-reduced AVMS that went on to complete obliteration underwent very early angiography (6-7 months). Fifty-five cerebral AVMs showed complete obliteration on early angiograms (40%). In this group, more follow-up, when performed, confirmed complete obliteration in all cases (n = 17). CONCLUSION: An early angiogram is needed to predict the effectiveness of radiosurgery. Important AVM changes seen on early angiograms are highly correlated with treatment success. Moreover, no or minor changes seen on early angiograms are highly predictive of radiosurgical failure. For these patients, further treatment should be discussed promptly.

Adolescent↗
PubMed1999

[Neurosurgical multicenter study of cerebral metastases (Neurosurgical departments of Paris Beaujon, Paris Sainte-Anne, Strasbourg)].

We report a multicentric outcome study of cerebral metastases in 174 patients collected consecutively in three neurosurgical centers in France. Age and condition of patients allowed surgical operation; the sex ratio was 1.67. The revelation mode was usual. However tumoral hemorrhage frequency was 3.4%. Primitive cancers were usual cancers as in oncological series with a higher proportion of radioresistant metastases. Mean dimension was 30 mm with mean of 1. 25 metastases per patient. Supratentorial localization was more frequent and the metastasis revealed cancer in 40% of cases. Global median survival was 12.1 months. Factors correlated with the survival in our series of patients with cerebral metastases were: solitary cerebral metastasis, extracerebral extension of cancer, treatment of primitive cancer, complete excision and post operative cerebral radiotherapy.

Adolescent↗
PubMed1999

[Radiosurgery for brain metastases].

This article presents the state of art in radiosurgery as a new therapeutic strategy of brain metastases. Radiosurgery of brain metastases is ten years old and we propose to make an update of the literature. X-rays and gamma-rays are commonly used for radiosurgery and does not make a difference for dosimetry and precision. Selected patients for this treatment have usually good Karnofsky status and the mean size of their metastases is about 20 mm. Mean number of metastases treated in the same procedure is 2. Most frequent primary sites are lung and breast, but also kidney and skin (malignant melanoma) which are supposed to be radioresistant and so often untreatable by other techniques. Usual dose administrated ranges between 15 and 25 Grays in center of target with a 80% isodose in peripheral. Results are quite good for local control (80% to 100%) but survival does not seem to be improved (11 months). Radiation complication rate is 4% and sometimes hemorrhagic complications occur (1 to 2%). For local control, quality of life and cost/benefit ratio, there are strong arguments in favor of radiosurgery, especially for radioresistant metastases in spite of the lack of improvement of survival duration. Moreover published studies do not allow any comparison with efficacy of surgery and radiosurgery, whole brain radiosurgery and radiosurgery of the present metastases. Evaluations are still going on in several centers. Their results will allow more precise indications of this technique.

Aged↗
PubMed1998

High-power diode laser in neurosurgery: clinical experience in 30 cases.

BACKGROUND: High-power semiconductor diode lasers were recently introduced and have been tested in ophthalmology and general surgery. These lasers are attractive from the practical and economical standpoint, and have enough power to perform most surgical procedures. They could replace other surgical lasers such as CO2, argon, 1.06 microm, and 1.32 microm Nd-YAG lasers for many applications in neurosurgery. We report our initial experience with the first available 0.805-microm surgical diode laser, the Diomed 25 (Diomed, Ltd, Cambridge, U.K.) in a series of 30 patients. METHODS: The diode laser was evaluated during surgical resection of various types of central nervous system tumors in 30 patients. It was used free-hand in 27 patients in contact and non-contact, continuous wave (cw) and pulsed modes, and during ventricular endoscopy in three patients. Average time of laser use during a procedure was 248 seconds. Output power ranged from 1 to 25 watts, with an average power per patient of 2.64 to 15.5 watts (mean, 8.78 watts). Total energy delivered ranged from 65 to 11,051 joules per patient. RESULTS: Using 600- or 400-microm non-contact optic fiber, well pigmented tumor tissue hemostasis was obtained at cw 3 to 10 watts with a defocused beam, whereas vaporization required 10-25 cw or pulsed watts with a focused beam. Soft and tough tissue section could be obtained using a sculpted cone-shaped (600-300 microm tip) contact fiber at 7-10 cw watts after fiber tip charring. Because of the deeper penetration of 0.805-microm light in non-pigmented tissues, non-contact mode is not recommended for white matter or poorly vascularized tumors. The contact mode was not efficient on very soft tissues such as edematous brain parenchyma. The contact fibers proved to be very fragile because of heat generation. CONCLUSIONS: The high power diode laser proved to be efficient for hemostasis, section and vaporization, using contact and non-contact modes, at different output powers. Economical and ergonomical advantages of this new generation of surgical lasers may cause them to replace other surgical lasers such as argon, CO2, and Nd-YAG lasers, mostly for tumor surgery.

Adolescent↗
PubMed1998

[Therapeutic strategy for cerebral arteriovenous malformations. Proposal for classification of individual hemorrhagic risk].

BACKGROUND AND PURPOSE: Therapeutic strategy for the cerebral arteriovenous malformations (cAVM) is mainly based on the assessment of hemorrhage risk. This risk is estimated between 2 and 4% according to various series. However, this is a collective risk projected upon a given population. To improve therapeutic strategy for cAVM, we propose a grading of the individual hemorrhage risk based on 5 angiographic parameters: 4 are increasing risk factors and one is a favorable index. METHOD: This grading system has been achieved by univariate then multivariate analysis by logistic regression from angiographic data of 250 consecutive patients with cAVM. Thirty angiographic parameters were studied. RESULTS: Grade I has no risk factors and has two subgrades: Ia with venous recruitment (which is the lonely favorable parameter), Ib without venous recruitment. Grade II is the presence of venous stenosis or venous reflux. Grade III is the presence of exclusive deep venous drainage. Grade IV is the presence of intra or juxta-nidal aneurysm. There were 13% of hemorrhage in grade Ia, 38% in grade Ib, 48% in grade II, 90% in grades III and IV. CONCLUSIONS: This model can be helpful for the treatment decision making and also contributes to a better understanding of the natural history of cAVM. It must be further confirmed by a prospective study.

Adolescent↗
PubMed1998

[The place of radiosurgery in the treatment of hypophyseal adenoma].

Since 1984, the neurosurgical team of Sainte-Anne Hospital in Paris has taken in charge almost 750 patients for linear accelerator radiosurgery. But only a small percentage of them were harbouring a pituitary tumor. That is why the present paper is based mostly on literature data. Pituitary adenoma radiosurgery (RS) is a second intention therapeutic method. It should be recommended only after failure of medical and/or surgical treatment. Two main methods can be used: linear accelerator-radiosurgery and Cobalt-60 gamma unit. Both procedures provide equivalent results in terms of dosimetry, accuracy and clinical data. Results of various series presented in recent and updated literature have been studied and analysed. They show and confirm the efficiency of radiosurgery on tumor and hormone secretion controls, with few cases of pituitary insufficiency. However, results were disappointing concerning visual disorders, particularly if visual dysfunction and impairment existed before radiosurgery. All authors agree nowadays on different points: a) indications: invasive adenomas, with an incomplete resection, or adenomatous recurrences, b) contraindications: tumoral size > 20 mm, distance to visual pathways < 5 mm, c) imperative precautionary measures: less than 8 Gray must be delivered on visual pathways, less than 40 Gray on oculomotor nerves. In some cases, stereotactic fractioned radiotherapy may be an alternative treatment for large tumors close to visual pathways.

Adenoma↗
PubMed1998

[Intracavernous extension of hypophyseal macroadenomas: infiltration or invagination?].

Frequency of intracavernous invasion by a pituitary adenoma varies from 9% to 40% depending on the publications. Without putting off the possibility of true intracavernous invasion, it seems less frequent than evocated on CT-Scan and/or MRI data. We studied 153 files of pituitary adenomas operated upon recently: 72 prolactinomas (47.3%), 30 GH-secreting adenomas (19.7%), 7 corticotrop adenomas (4.6%), 44 non secreting adenomas (28.3%). 108 patients (70.4%) harboured a macroadenoma (diameter > 10 mm). A suprasellar expansion was seen 90 times on CT-Scan and/or MRI views. 19 times (17.7% of macroadenomas, 12.5% of the whole series) MRI evocated an infiltration of one or both cavernous sinuses (CS). Such data were found 3 times before 1991, 16 times since 1991, i.e. since MRI is systematically performed preoperatively. Except in two patients who respectively presented with a large intraorbital or temporal expansion, we have not been able to confirm the reality of the intracavernous invasion. We think that most of CT-Scan or MRI data of so-called intracavernous invasion correspond in fact to a compression or to a fingerglove invagination of the medial wall of the CS. In fact, anatomical studies by Harris & Rhoton (1976) and by Taptas (1990) demonstrated that such an invagination of the medial wall exists in almost one third of normal pituitary glands. These data must bring up to much carefulness when considering a possible pathological CS invasion by a macroadenoma. Therefore, it should be thoroughly assessed with anatomoradiological and radio-surgical correlations.

Adenoma↗
PubMed1998

[Controversies in the management of operated pituitary macroadenomas].

BACKGROUND AND PURPOSE: Complete resection of a pituitary adenoma is feasible in almost 50 to 70% of cases. Dealing with the remnant is still controversial. Three positions can be discussed: second stage operation, radiation therapy, clinical and radiological follow-up. METHODS: Among 108 pituitary macroadenomas operated on during the last 10 years, 54 patients (50%) with partially removed tumors were studied. Three cases best illustrating the evolution of these remnants are reported. RESULTS: Late MRI performed 4 to 6 months postoperatively is more valuable than early MRI in the evaluation of these remnants, which can remain stable for a long period of time without any adjuvant treatment. CONCLUSION: MRI should be performed 4 to 6 months postoperatively. Rather than performing radiation therapy systematically for asymptomatic patients, these patients should be followed up at regular intervals and treated only in case of regrowth of the tumor.

Adenoma↗
PubMed1997

Angioarchitecture associated with haemorrhage in cerebral arteriovenous malformations: a prognostic statistical model.

The overall haemorrhagic risk of a cerebral arteriovenous malformation (cAVM) is 2-4% per year. However, the individual risk of haemorrhage has never been determined. This study was undertaken to assess the haemorrhage risk of an individual cAVM. Neuroangiographic findings of 160 cAVM were analysed retrospectively, looking at 30 angiographic features. A statistical model was established by logistic regression to evaluate the risk of an individual cAVM. We statistically correlated 15 parameters with the haemorrhage risk. The statistical model includes five independent parameters. Four are unfavourable: exclusively deep drainage, venous stenoses, venous reflux and the radio of afferent to efferent systems; one is favourable: venous recruitment. This model quantifies the individual risk of haemorrhage. When this model is applied to the population studied, the error rate is 5%. This model can contribute to therapeutic strategy, and to a better understanding of the natural history of cAVM.

Adolescent↗
PubMed1997

Congenital lumbosacral lipomas.

Congenital lumbosacral lipomas can be responsible for progressive defects. The general feeling is that tethering of roots, filum, or cord probably explains this evolution, and that untethering of these structures could prevent late deterioration. Like the vast majority of neurosurgeons, we too have routinely and systematically operated on lumbosacral lipomas, even in the absence of neurological deficits. This policy stemmed from our belief that spontaneous neurological deterioration was frequent, recovery from preoperative deficits rare, and surgery both efficient and benign in nature. After 22 years of experience, we felt that it was necessary to review our series of 291 lipomas (38 lipomas of the filum and 253 of the conus) operated on from 1972 to 1994. To reassess the value of prophylactic surgery, we attempted an accurate evaluation of (1) the risk of pathology, (2) the risks involved in surgery, (3) the postoperative outcome with respect to preoperative deficits, and (4) the postoperative outcome in asymptomatic patients at 1 year and at maximum follow-up. Special attention was paid to 93 patients whose postoperative follow-up was more than 5 years (average 8.7, median 8, range 5-23 years). Of these 93 patients, 39 were asymptomatic preoperatively (7 with lipoma of the filum and 32 with lipoma of the conus). Lipomas of the filum and of the conus are entirely different lesions and were studied separately. In 6 cases prenatal diagnosis had been possible. The mean age at surgery was 6.4 years. Low back skin stigmata were present in 89.4% of cases. Preoperative neurological deficits existed in 57% of the patients and were congenital in 22%. Clinical signs and symptoms recorded were pain in 13.3% of the patients and/or neurological deficits affecting sphincter (52%), motor (27.6%) and sensory (22.4%) functions. Deficits were progressive in 22.4% of cases, slowly progressive in 58.8% of these and rapidly progressive in the remaining 41.2%. In 36 patients (13.2%) the lipomas were seen to grow either subcutaneously or intraspinally. Among these patients, 21 were infants, 2 were obese adolescents, and 10 were pregnant women. The metabolism of the fat within the lipomas was studied in 11 patients and found to be similar to that at other sites. Lipomas were associated with various other malformations, either intra- or extraspinal. These associated anomalies were rare in the case of lipomatous filum (5.2%) but frequent with lipomas of the conus, except for intracranial malformations (3.6%). Therapeutic objectives were spinal cord untethering and decompression, sparing of functional neural tissue and prevention of retethering. Procedures used to achieve these goals were subtotal removal of the lipoma, intraoperative monitoring, duroplasty, and sometimes closure of the placode. Histologically, lipomas consisted of normal mature fat. However, 77% of them also included a wide variety of other tissues, originating from ectoderm, mesoderm, or entoderm. This indicates that lipomas are either simple or complex teratomas. The results of the study are as follows. (1) Surgery was easy and safe when performed for treatment of lipomas of the filum (no complications), but difficult and hazardous in the case of lipomas of the conus (20% local, 3.9% neurological complications). (2) All types of deficit could be improved by surgery, which was beneficial in all cases of lipoma of the filum and 50% of cases of lipoma of the conus. (3) In asymptomatic patients long-term surgical results depended on the anatomical type of the lipoma. They were excellent in lipomas of the filum. In lipomas of the conus they were good in the short term but eroded with time. At more than 5 years of follow-up only 53.1% of the patients were still free of symptoms. (4) Reoperations were performed in 16 patients (5.5%), 5 (31.2%) of whom improved postoperatively, while in 7 (43.7%) progression stopped, in 3 (18.7%) deterioration continued and in 1 (6.2%) the condition was wor

Adolescent↗
PubMed1997

Parenchymal changes after radiosurgery of cerebral arteriovenous malformations. Preliminary report of a proposed classification.

Radiosurgery of cerebral arteriovenous malformations (cAVM) can induce parenchymal changes seen on MRI. The purpose of this study was to classify these changes and to correlate them to clinical outcome and obliteration of the cAVM. 142 patients with cAVM underwent radiosurgery with a linear accelerator between 1994 and 1995. 60 clinical records, MR images, and postradiation angiograms were reviewed. Signal abnormalities and contrast enhancements were correlated with clinical deterioration and size decrease of the AVM. The Spearman nonparametric test was used for statistical correlation. MR findings allowed to differentiate between four grades: grade 1 = no parenchymal changes; grade 2 = hypersignal on T2-weighted sequences, grade 3 = grade 2 + contrast enhancement on T1-weighted sequences; grade 4 = grade 3 + central hyposignal (necrosis-like) + peripheral hyposignal surrounding the AVM on T1-weighted sequences. Grade 4 was significantly related (p < 0.001) to clinical deterioration (deficit, seizures, increased intracranial pressure). All grade 4 patients, and only them, had clinical symptoms. Most of these symptoms regressed with corticoid treatment. Grade 4 was also related to the proportion of obliteration of the cAVM at 1 year after radiotherapy: mean proportion of obliteration was 12.5% for grade 2, 25% for grade 3 and 82.2% for grade 4 (p < 0.01). The size of T2-weighted MR images was related to clinical symptom appearance (p < 0.001). Finally, contrast enhancement was not predictive of the occurrence of the clinical symptoms. This proposed classification allows one to differentiate between the various MR images, and seems to predict clinical complications and response to radiotherapy of the cAVM.

Brain↗
PubMed1997

[Malignant tumors of the ethmoid region. Neurosurgical techniques].

We describe the main neurosurgical approaches in use for removing cancers of the ethmoid region: a) the classical subfrontal procedure usually combined with a transfacial approach, b) the sub-fronto-orbito-nasal approach (SFON) now performed in a majority of procedures as long as the tumor does not present with a large intra-cranial and/or maxillary extension. The advantages and drawbacks of both techniques are discussed. The progressive simplification of techniques for anterior cranial base reconstruction is explained and warranted.

Ethmoid Bone↗
PubMed1997

[Malignant ethmoid-sphenoidal tumors. 130 cases. Retrospective study].

We report on 130 ethmoidal cancers. 96 (74%) were adenocarcinomas (ADKE). 110 were operated upon between 1984 and 1996: 9.1% T1 + T2, 27.7% T3, 36.2% T4a, 27% T4b. Neoadjuvant chemotherapy was administered in 93 patients (76 ADKE). Combined surgical route was performed 103 times, sub-fronto-orbito-nasal (SFON) route 7 times. Post-operative radiotherapy was performed in 36 patients. Complete clinical and radiological response to chemotherapy was noted in 21.5% of cases (23% of ADKE). Post-operative mortality concerned one patient who died from a pulmonary embolism during the third post-operative week. Morbidity included: 3 transient clinical rhinorrheas, 5 meningitis (one of which was responsible for heavy psycho-intellectual disability), 4 deep suppurations associated with osteitis of the bone flap and two superficial suppurations. 44 patients had a local recurrence (10 ADKE). No recurrence appeared in complete chemoresponders. Systematic preservation of intra-orbital contents did not increase the risk of local failure. Eleven patients (4 ADKE) developed cervical nodes and/or systemic metastasis. Death occurred after a mean of three months following the diagnosis of metastasis. Survival rate was: 60% at 3 years, 51.5% at 5 years, 32.5% at 10 years. ADKE survival rate was: 55% at 3 years, 51.5% at 5 years, 23% at 10 years. Survival ws related to tumoral extension: 75% at 5 and 10 years for T3, 45% at 5 years and 38% at 10 years for T4a, 40% at 3 years and null at 5 years for T4b, 5 and 10 years survival rate of complete chemoresponders are 100% whatever the tumour. Prognosis remained poor for epidermoid carcinomas (survival rate: 36% at 3 years, 0% at 5 years) and for melanomas (mean survival: 19.6 months). Post-operative radiotherapy should be indicated for large tumors T3, T4a and T4b).

Adenocarcinoma↗
PubMed1997

Cerebral arteriovenous malformations: the value of radiologic parameters in predicting response to radiosurgery.

PURPOSE: To define the morphological patterns of cerebral arteriovenous malformations (AVMs) that influence their response to radiosurgery at 2 years. METHODS: We retrospectively reviewed the yearly MR and angiographic follow-up studies in 102 patients who had radiosurgical treatment for cerebral AVMs between 1990 and 1992. Parameters studied were maximum length and volume of the nidus, position relative to the midline, anatomic structures involved, sectional anatomic location (depth within the brain tissue), angioarchitecture, and Spetzler and Martin grading. Statistical analysis determined their influence on treatment results at 2 years. RESULTS: Parameters that correlated with obliteration at 2 years were maximum length less than 25 mm, small volume, sectional location deep within brain tissue, and plexiform angioarchitecture. Ventricular and paraventricular locations correlated with nonobliteration at 2 years. CONCLUSION: This study highlights the role of two new morphological parameters in predicting the efficiency of radiosurgery in the treatment of cerebral AVMs: depth within the parenchyma and angioarchitecture. It also emphasizes the usefulness of sectional imaging in the work-up before radiosurgery.

Adolescent↗
PubMed1997

[Stereotaxic technics and clinical neurosurgery].

Stereotactic methodology developed at Sainte-Anne Hospital Center from 1947 is based on the application of a simple spatial geometry-the Talairach Ac-Pc reference system-to the cranial volume and the identification of any anatomical structure or brain lesion within this volume. Now upgraded with modern imaging techniques, this methodology is the ground for multiple applications in functional as well as lesional neurosurgery and is now a a part of the daily neurosurgical practice at Sainte-Anne Hospital. Stereotactic procedures include three steps: first, the identification of one or several target-volumes through stereotactic imaging acquisition: CT, MRI and conventional stereoscopic angiography; second, the image treatment on a dedicated workstation for stereotactic coordinates determination and surgical planning; third, the surgical procedure itself and its control. The most frequent applications for stereotactic methodology are: image-guided stereotactic biopsies of brain tumors, in order to obtain tissue pathological diagnosis and spatial configuration; linac-based radiosurgery of arterio-venous malformations and tumors with high energy collimated beams converging towards a simple or complex target volume; surgery for partial drug-resistant epilepsy including depth electrode implantation for stereo-electroencephalography and epileptogenic cortex resection; stereotactic image-guided resection of superficial or deep-seated tumors or vascular malformation; Rhenium 186 intracavitary irradiation of cystic tumors such as craniopharyngiomas.

Biopsy↗