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Biomedical subjects

D Renier

Publications and source records attributed to D Renier.

At least 91 records · Page 5Linked to original sources
PubMed1995

No evidence of genetic heterogeneity in Crouzon craniofacial dysostosis.

Crouzon craniofacial dysostosis (CFD) is an autosomal dominant form of craniosynostosis characterized by an abnormal skull shape, with hypertelorism, prominent eyes and midfacial retrusion. Recently, a gene for CFD has been mapped to chromosome 10q25-q26 and mutations in exon B of the fibroblast growth factor receptor 2 (FGFR2) gene have been identified. Here, we report the mapping of a CFD gene to chromosome 10q by close linkage to probe AFMa197wb1 at locus D10 S1483 in six unrelated families of French ancestry (Zmax = 4.69 at theta = 0) and provide additional evidence of genetic homogeneity of this condition. In addition, we report a novel mutation in exon B of the FGFR2 gene (Cys 342 Trp) in familial CFD and describe recurrent mutations at codon 342 as a particularly frequent event in CFD. Since mutations in the extracellular domain of the FGFR2 gene are observed in a few clinically distinct craniosynostosis syndromes (CFD, Jackson-Weiss, Apert and Pfeiffer), the present study gives support to the variable clinical expression of FGFR2 mutations in humans.

Chromosome Mapping↗
PubMed1995

Prognosis for mental function in scaphocephaly.

Three hundred ninety-six children with scaphocephalies were prospectively studied to analyze the correlation between age, intracranial pressure (ICP), and mental function outcome. The ICP measurements and the early and late psychometric assessments were compared. The influence of surgery, when performed, was analyzed. In most cases, the mental function outcome of the patients was good whether or not they had undergone surgery. The mental level and the frequency of increased ICP both correlated with patient age. A correlation was found between the early and late psychometric assessments in all patients. Thus, the main predictive factor of mental function outcome appears to be the initial developmental level.

Brain↗
PubMed1995

Hydrocephalus associated with intramedullary low-grade glioma. Illustrative cases and review of the literature.

Over the past 15 years, eight children affected by intramedullary low-grade gliomas associated with hydrocephalus were treated at l'Hôpital des Enfants Malades. In all cases the diagnosis of hydrocephalus was made prior to that of the spinal tumor. Neuroradiological examination of all patients revealed contrast enhancement of the intracranial subarachnoid spaces. In six cases this was progressive, suggesting subarachnoid spread of the tumor, which was confirmed in two cases by histological examination. The authors analyzed 38 cases of intramedullary low-grade glioma associated with hydrocephalus that were reported in the literature. Fifteen of the cases had intracranial leptomeningeal seeding. Several hypotheses have been proposed to explain this unusual association, such as 1) increase in cerebrospinal fluid (CSF) viscosity because of elevated fluid protein content; 2) obliteration of the cisterna magna due to a rostral extension of the tumor; and 3) blockage of the spinal subarachnoid pathways of CSF resorption. Two other theories seem of particular interest. Bamford and Labadie suggested that the abnormal presence of fibrinogen in the CSF and its transformation into fibrin at the level of the basal cisterns and Pacchioni's granulation may alter CSF hydrodynamics. This mechanism alone is sufficient to induce hydrocephalus of the communicating type. In addition, as suggested by Maurice-Williams and Lucey, the resulting leptomeningeal fibrosis might predispose secondary implantation of neoplastic elements in the subarachnoid spaces of the intracranial compartment.

Adolescent↗
PubMed1995

Chronic tonsillar herniation in Crouzon's and Apert's syndromes: the role of premature synostosis of the lambdoid suture.

The incidence of chronic tonsillar herniation (CTH) was evaluated with magnetic resonance imaging in 44 patients with Crouzon's syndrome and 51 with Apert's syndrome; the incidence was 72.7% in Crouzon's syndrome and 1.9% in Apert's syndrome. All the patients with Crouzon's syndrome and progressive hydrocephalus had CTH, but of 32 individuals with Crouzon's syndrome and CTH, only 15 had progressive hydrocephalus. Five patients with Apert's syndrome were treated for progressive hydrocephalus; none had CTH. The patterns of suture closure in these two groups of patients were studied, and significant differences in coronal, sagittal, and lambdoid sutures were found between patients with Crouzon's and Apert's syndromes. In Crouzon's syndrome, significant differences in the pattern of lambdoid suture closure were found between the groups with and without CTH; in the group with CTH, the lambdoid closure appeared earlier. The authors propose that the high incidence of individuals with CTH who have Crouzon's syndrome is related to the premature synostosis of the lambdoid suture in the first 24 months of age.

Acrocephalosyndactylia↗
PubMed1995

Evaluation of the effect of early mobilization of the supraorbital bar on the frontal sinus and frontal growth.

Consequences of early frontocranial remodeling are controversial. It has been said that secondary operations are more difficult and that the frontal sinus does not develop well, with an adverse effect on forehead aesthetics. Some illustrative cases are presented, among 820 operated craniosynostoses, to demonstrate that (1) an early, well-performed frontal advancement and/or remodeling is followed by satisfactory reossification and permits easy secondary surgery, (2) frontal sinus development, which is always impaired in anterior craniosynostosis, is only moderately diminished by early supraorbital bar remodeling (when the frontal bar is repositioned after remodeling, as with trigonocephaly, the frontal sinus develops in 83 percent of cases, whereas when the advancement is significant, as with brachycephaly, the development of the frontal sinus is observed in only 50 percent of the cases), and (3) forehead aesthetics are not linked closely to the development of the frontal sinus. After a significant advancement, even if the sinus does not develop, the frontal bar projection can remain satisfactory.

Child↗
PubMed1994

Timing of treatment for craniosynostosis and facio-craniosynostosis: a 20-year experience.

The timing of surgery for craniosynostosis is still controversial. Having used the same basic techniques since 1973, and having done follow-up on the growth of our 983 operated patients, we thought it useful to report our protocol. Early frontocranial remodelling is performed between 2 and 4 months for brachycephalies, but the other craniosynostoses are operated on between 6 and 12 months of age. When diagnosis is made later, we perform the same operations until 4 years of age, with some modifications, such as a tongue in groove advancement for brachycephalies, and a complete closure of the bony defects after 2 years of age. Later on, facial distortion and frontal sinus development complicate the surgery. For syndromal craniofacial synostosis, we prefer to perform a two-step operation: forehead advancement first, facial advancement later, to avoid the risk of frontal osteitis. The frontofacial monobloc is indicated, in our opinion, for severe exorbitism in infancy but otherwise we prefer a two-stage procedure. Facial bipartition is necessary to narrow the upper face and widen the maxilla in Apert's syndrome.

Acrocephalosyndactylia↗
PubMed1994

Surgical approach to children with craniopharyngiomas and severely impaired vision: special considerations.

A series of 30 children with craniopharyngiomas is presented, analyzing visual sequelae following surgery. All were operated on with the goal of total removal. Surgical routes used were subfrontal prechiasmatic or translamina terminalis, pterional interopticocarotid, transcallosal, or a combination of these various avenues. The choice of the approach depended upon the type, pre- or retrochiasmatic, of the tumor expansions. Children with large cysts and preoperatively low vision, or vision at risk of rapid deterioration, were submitted to a protocol aiming to preoperatively decompress the visual pathway by repeated aspirations of the cyst with the hope this would improve vision before surgery and limit risks of postoperative visual deterioration. In these cases, the removal of the tumor was postponed until vision had reached a stable new level. The authors emphasize the interest of this procedure in reducing the rate of postoperative visual sequelae. However, they also point out that the interopticocarotid route carries a nonnegligible risk of postoperative visual worsening.

Adolescent↗
PubMed1994

[Development of the frontal sinus after frontocranial remodeling for craniostenosis in infancy].

General considerations about frontal sinus development are discussed. This retrospective radiological study concerns 90 craniosynostoses among 850 cases operated in the Cranio-Facial Unit (1976-88, Hôpital Necker des Enfants Malades, Paris, France). The incidence of frontal sinus development is compared between a control group and the craniosynostoses group with a mean age at surgery of 3 years and a mean follow-up of 6.5 years. Pneumatization of the frontal bone seemed to vary according to the type of surgery and the age at review, but was not linked to sex and age at surgery. A classification of fronto-cranial remodelling is suggested.

Adolescent↗
PubMed1994

[Glabellar morphology after frontocranial remodeling for craniosynostosis in infancy].

This retrospective clinical and radiographic study concerns 75 cases of craniosynostoses among 850 cases operated in the Craniofacial Unit of Necker's Hospital for Sick Children (1976-1988, Paris, France). The correlation between frontal sinus development and glabellar morphology was analyzed. When there was a significant advancement of the supraorbital ridge the projection of the glabella was satisfactory without any frontal sinus. When no significant advancement was performed, the pneumatization of the frontal bone was as frequent as in the general population and was dependent upon the underlying frontal sinus.

Adolescent↗
PubMed1994

Development of the frontal sinus and glabellar morphology after frontocranial remodeling for craniosynostosis in infancy.

General considerations about frontal sinus development are first discussed. We include retrospective clinical and radiographical studies dealing with 90 craniosynostoses among 850 patients operated in the Craniofacial Unit of Necker's Hospital for Sick Children (1976-1988; Paris, France). The incidence of frontal sinus development is analyzed: The pneumatization of the frontal bone seemed to develop according to the type of surgery and to the age at which review was realized, but was not linked to the age at which surgery was performed. The surgery consisted of fronto-orbital remodeling after supraorbital bar mobilization. The median age at surgery was approximately 3 years, and the median length of the postoperative follow-up was 6.5 years, depending on the type of pathology. The correlation between frontal sinus development and glabellar morphology are also analyzed: When there was a significant advancement of the supraorbital bar, the projection of the glabella was satisfactory without any frontal sinus. When no significant advancement was performed, pneumatization of the frontal bone was as frequent as in the general population and was dependent on the underlying frontal sinus. A classification of the different type of frontal advancement is proposed.

Adolescent↗
PubMed1993

Malignant hemispheric tumors in childhood.

Sixty-four malignant hemispheric tumors in children less than 15 years old were treated in the pediatric neurosurgical department of the Hôpital des Enfants Malades between 1970 and 1989. (1) These tumors evolved rapidly in most cases. However the pre-operative evolution in 20% of the patients had a duration of more than 6 months, which favors the hypothesis that at least one-fifth of these tumors result from malignant transformation of a benign lesion. This observation should prompt neurosurgeons to operate on all benign hemispheric tumors as soon as they are diagnosed. (2) Five of the 64 patients had two successive malignant diseases. In four cases the other malignant disease was an acute lymphoblastic leukemia. (3) Among the malignant hemispheric tumors, the grade III and IV astrocytomas had a dismal prognosis. As it is known from previous studies that grade I and II astrocytomas have a good prognosis in children, it can be concluded that grading these tumors is essential. By contrast, almost one out of two patients with malignant ependymoma was alive 5 years after treatment. This implies that the grading of ependymomas is of modest prognostic values. (4) The harmful effect of radiotherapy was evaluated by comparing the functional outcome of children operated for a benign hemispheric tumor to that of children operated and irradiated for a malignant hemispheric tumor.

Adolescent↗
PubMed1993

Blood loss during repair of craniosynostosis.

Surgical repair of craniosynostosis carries a high risk with large blood losses. Over a 2-yr period, we have managed 115 patients undergoing craniosynostosis repair with peroperative haemodilution to achieve a final PCV of 0.28-0.35. Measurements of PCV allowed calculation of estimated blood losses and transfused volumes in terms of red blood cell mass. Total estimated red cell volume lost was 91 +/- 66% of patient's estimated red blood cell volume during the peroperative period. The type of skull deformation and surgical procedure determined the extent of peroperative bleeding. Peroperative transfusion was satisfactory in 48% of patients and slight overtransfusion was noted in 32%. During the postoperative period, liberal administration of blood led to overtransfusion and possibly unnecessary transfusion in 74% of patients. Because of the well known risks of transmission of infectious disease, strict volume compensation with development of haemodilution and autotransfusion procedures should be used to limit these risks.

Age Factors↗
PubMed1993

Surgical management of brain-stem tumors in children: results and statistical analysis of 75 cases.

A study was made of 75 children treated between 1970 and 1990, with partial, subtotal, or total removal of three intrinsic and 72 exophytic or surface brain-stem tumors. In all cases, the goal of surgery was to remove as much tumor as possible. Extent of removal was defined according to data obtained from postoperative computerized tomography or magnetic resonance imaging, and was considered partial when only a small amount of tumor was removed, subtotal when a few cubic millimeters of tumor was left, and total when no residual tumor was seen on postoperative radiological investigations. An ultrasonic aspirator was used for the 43 most recent operations. Among tumor removals without the aspirator, 24 (75%) were partial, eight (25%) subtotal, and none total; with the use of the aspirator, the number of partial removals decreased to 44.5% while that of subtotal and total removals increased to 32% and 23.5%, respectively. There were 69 gliomas (92%) and 47 benign tumors (62.6%). Forty-nine patients were irradiated postoperatively, and 14 of the 23 patients whose benign tumors were removed totally or subtotally did not undergo irradiation. This study showed that: 1) the overall prognosis of patients with malignant tumors was poor and was not improved by surgery; 2) the survival rate of those with benign tumors was significantly (p < 0.01) lower after partial removal than after total or subtotal removal (52% and 94%, respectively, at 5 years); 3) comparison of means and proportions (Student's and chi-squared tests) between benign and malignant tumors showed a significant difference relating to patient age (p < 0.03), peritumoral hypodensity (p < 0.001), and preoperative duration of symptoms (p < 0.001); 4) stepwise logistic regression analysis confirmed that two of these three variables were related to malignancy: namely, patient age at surgery (p < 0.03) and presence of peritumoral hypodensity (p < 0.001); and 5) routine postoperative irradiation was contraindicated after total or subtotal removal of benign tumors.

Adolescent↗
PubMed1993

Lack of ossification after cranioplasty for craniosynostosis: a review of relevant factors in 592 consecutive patients.

The Center for Craniofacial Anomalies of Necker-Enfants-Malades Hospital presents a retrospective study of the outcome of 592 patients who were operated on for craniosynostosis between 1976 and 1991. The quality of ossification 1 year after operation is reported, with a focus on influencing factors. The lack of ossification rate was 5% (30 of 592). Three parameters are identified as increasing the risk of poor osseous wound healing: local postoperative infection; forehead advancement, especially when accomplished with resorbable osteosynthesis; and brachycephaly. In contrast, repaired tears of the dura mater do not seem to pose a risk. Seventy-five percent of patients with local infection and 12.4% with forehead advancement presented a lack of ossification, which is statistically significant (p < 0.001). Lack of ossification can compromise aesthetic and functional results. Decreasing postoperative infection and stable fixation may help promote ossification.

Adolescent↗
PubMed1992

[The value of CT and MRI in the assessment of basal encephaloceles in children].

Basal cephaloceles of the child are rare pathologies which require accurate preoperative imaging work-up. The CT and MR studies of six children with surgically proven basal cephalocele were retrospectively reviewed to evaluate the role of CT and MR in the preoperative work-up of a basal cephalocele of the child. In five patients, MR allowed to define the nature and topography of the cephalocele, and allowed an accurate depiction of the optic tract, ante- and post-hypophysis and associated agenesis of corpus callosum when present. 3-D CT allowed in one case a more precise depiction of the basal bony defect. MRI allows in a non invasive and non ionising way the best depiction of herniating meninges, brain or ventricles as well as associated cerebral anomalies.

Child↗
PubMed1992

Intracranial pressure and intracranial volume in children with craniosynostosis.

Intracranial volume and intracranial pressure have been measured in 66 children with craniosynostosis, 48 boys and 18 girls. The premature fusion of skull sutures is assumed to restrict skull growth and predispose to elevated intracranial pressure. Thirteen children (20 percent) had raised intracranial pressure and demonstrated a significant restriction of skull growth. In this series, volume measurement alone, however, did not serve as a reliable predictor that the intracranial pressure was raised.

Adolescent↗