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Biomedical subjects

D Renier

Publications and source records attributed to D Renier.

At least 163 records · Page 9Linked to original sources
PubMed1979

A new surgical approach to the third ventricle with interruption of the striothalamic vein.

In the removal of tumours that develop within the third ventricle, most approaches are not entirely satisfactory. Therefore, a new approach has been devised: transfrontal exposure of the anterior portion of the frontal horn; coagulation and section of the striothalamic vein in order to open up the roof of the third ventricle; use of a blunt spatula introduced in the foramen of Monro and pushed backwards under the choroïd plexus. This approach has been used in ten cases. Postoperative mortality has been nil; the surgical approach has not apparently been responsible for any sequelae. It is simple and gives a good view of the third ventricle.

Adolescent↗
PubMed1978

Influence of the use of a surgical isolator on the rate of infection in the treatment of hydrocephalus.

Two series of patients treated for hydrocephalus (101 original shunt insertions, 81 revisions and 35 reinsertions after infections) have been operated on in the same location, 146 with a surgical isolator (SI), 71 without a SI. Due to temporary poor technical conditions, the use of a SI was decided because, the overall rate of acute postoperative infections had suddenly increased from 9 to 19.7%. Then, although these technical conditions remained unchanged, the use of the SI immediately reduced the overall rate of acute postoperative infections from 19.7 to 7.4%. In original shunt insertions, this rate decreased from 24.9 to 5.8% and in revisions from 10.7 to 5.5%. In reinsertions after infection, it only fell from 27.2 to 16.6%. With the SI, the rate of peroperative contamination is almost nil. If postoperative contaminations due to wound disruption or scalp necrosis, and shunt reinsertions after infection are not taken into account, the rate of acute postoperative infection is 0.8%. The data presented indicate the efficiency of the SI. This results from elimination by the SI of airborne contamination and errors in aseptic technique. These two factors are probably the main sources of infection in shunt insertions for hydrocephalus.

Cerebrospinal Fluid Shunts↗
PubMed1978

[Study of the relationship between intracrânial pressure and paradoxal sleep in the cat (author's transl].

The present study reports on the modification of the intracranial pressure (ICP) during rapid eye movements (REM) sleep in seven chronic cats. 1. REM sleep episodes were characterized by a succession of short lasting (9 +/- 4 seconds) oscillations of the ICP. Peaks amplitude represented a hundred percent increase of the pressure as compared to its resting level. 2. These oscillations either arose from an ICP level similar to that recorded during the preceding slow wave sleep period or were seen to overide a wave of raised ICP that lasted throughout the REM period. 3. Eighty eight percent of the phasic oscillation coincided with a burt of eye movement characteristic of REM sleep. 4. Cerebral pulse wave amplitude can vary for identical ICP mean value in the course of a same REM period.

Animals↗
PubMed1978

[Fronto-cranial remodeling for craniostenosis with mobilisation of the supra-orbital barr (author's transl)].

33 cases of fronto-cranial remodeling by osteotomies are reported by the authors. Since 1973, 19 oxycephalies have been operated according to an original technique based on two principles:--rocking and advancement of the supra-orbital barr, with an easy lateral retention by a Z-bony cut.--transposition of free bone flaps to rebuild a forehead of the appropriate curvature. The good results obtained have encouraged the authors to operate on young children or even babies in order to solve simultaneously the functionnal and the aesthetic problems. Three plagiocephalies, two trigonocephalies have thus been treated, as well as 5 facio-craniostenosis for whom a 2 cm forehead advancement has been done, the following results being very encouraging.

Child↗
PubMed1978

[Measuring intracranial pressure with a fontanelle palpation transducer (author's transl)].

The accuracy and reliability of a non-invasive method for the measurement of intracranial pressure through the fontanelle without puncture was tested during 12 or even 24 hours recordings. Wealthall and Smallwood modified aplanation transducer was first used. A metal frame had to be developed in order to secure the transducer rigidly over the fontanelle so that the recording could take place with the infant in any position and completely free of its movements. Simultaneous recordings of extradural or intraventricular pressure have shown the measurements were accurate to about 1 or 2 cm H2O in a neurosurgical environnement (i.e large fontanelles with pressure over 10 cm H2O). For smaller fontanelles or low or even negative intracranial pressure, a smaller transducer seems to be needed. The preliminary test of a plane strain gauge transducer that partially fills this need is shown.

Circadian Rhythm↗
PubMed1978

[Medulloblastoma in childhood. Survival rates and functional results (author's transl)].

The authors report on a series of 57 medulloblastomas operated upon in children from 1964 ot 1976. Among these children, 44 completed the treatment with radiotherapy of the whole central nervous system. The post-operative mortality rate in 10,5%. Postoperative death occurred mainly in infants or when the tumor involved the brain stem. The five years survival rate is 46,6% in the whole series. It raises up to 50% in the series of the patients who completed the treatment with radiotherapy. The study shows that the life of survivals is frequently impaired by mental or behavioural disturbances. I.Q. varies from 70 to 90 in 66% of the children; it is below 70 in 20%. Behavioural disturbances are found in 91% of cases, wrong space orientation, speech or writing disabilities in 87%. In order to evaluate the responsibility of ray therapy in the development of these sequelae, the results have been compared to those of a series of cerebellar astrocytomas surgically removed, but not irradiated. The comparison shows that radiotherapy is at least partially responsible for the mental and behavioural disturbances.

Adolescent↗
PubMed1977

[Angioventriculography in the study of deep arteriovenous aneurysms].

The authors discuss the value of angioventriculotomography before surgery in deep arteriovenous malformations. This new procedure was performed in 2 infants and 3 children. In all cases, it was possible to know the precise relations of the lesions to deep structures of the central nervous system. Surgery was then contra indicated in two patients. In the remaining three patients, it not only proved to be of great value before deciding surgery, but it also determined the entire surgical procedure. The only incident encountered in this series was a rapidly regressive convulsive seizure in an infant of 3 months.

Adolescent↗
PubMed1975

[Role of the ventriculocisternostomy in the treatment of non-communicating hydrocephalus].

44 ventriculo-cisternostomies were carried out on infants and children who manifested non communicating hydrocephalus. They were performed through perforation of the floor of the 3th ventricle with the aid of a leukotomy trochar which was introduced through a frontal ventriculography burr hole, and then guided under X ray control. The study of this group showed that the operation is benign, although the mortality is not null, and is effective except in the case where non communicating hydrocephalus develops after meningeal haemorrhage of meningitis. The late results seem good, but the time lapse is too short for a final conclusion. The preoperative radio-isotopic cisternography does not unable prediction of the cases which will be failures; it does however sometimes make it possible to foresee those which will be successful. The post-operative radio-isotopic cisternography is useful in checking on the permeability of the shunt.

Cerebral Ventricles↗
PubMed1975

[Neurosurgery under strict asepsis. Effect of the surgical isolator on the level of infections after valve shunts for hydrocephalus].

The authors report on two groups of 75 shunts for hydrocephalus. Each group includes both cases in which the shunt was implanted for the first time and cases in which the repair of a former shunt was necessary either for mechanical or infectious complications. The operations within the first group were performed with traditional techniques; those of the second group were carried out during the same period of time and by the same team, but with the use of a surgical isolator. The overall rate of early infections was greatly reduced in the second group. Careful analysis of the infections which still occured with the surgical isolator indicated that they were related to the reappearance of a preoperative infection or to secondary contamination through post-operative cutaneous complication. In this second group using the surgical isolator, no contamination occured during the operation itself.

Antisepsis↗
PubMedDate not supplied

Craniosynostosis.

Craniosynostosis affects approximately one infant out of one thousand. Increase of intracranial pressure and risks of functional problems are more frequent than previously thought, especially in single-suture synostosis. Frontocranial remodeling will correct both functional and esthetic consequences of craniosynostosis. The best time for surgery is the first year of life, 2-3 months of age for the brachycephalies, and 6-9 months of age for the other craniosynostoses. Not only does growth not deteriorate after forehead remodeling, but the adjacent orbitonasal areas improve with time. In Crouzon's disease and Apert's syndrome, early frontal advancement does not prevent the midface retrusion, and a radical frontofacial advancement may be occasionally indicated in very severe cases. Frontocranial remodeling is also indicated in children presenting with sequelae of classical neurosurgical treatment or those who have had no treatment.

Adult↗
PubMedDate not supplied

New aspects of craniofacial surgery.

The concept of craniofacial surgery, introduced by a French plastic surgeon named Paul Tessier, has completely transformed the treatment of facial deformities affecting the skeleton. Two of the more spectacular operations are correction of teleorbitism by orbital mobilization, and correction of facial retrusion by facial or fronto-facial advancement. These operations have evolved with the bipartition principle and the monobloc and splitting techniques. Craniofacial techniques applied in infancy for correction of craniosynostosis have proved very successful in most cases. The increasing use of miniplate fixation and utilization of cranial bone grafts are mentioned, as well as advances made in genetic and fetal diagnosis.

Bone Transplantation↗
PubMedDate not supplied

The influence of molecular weight on the biological activity of heparin like sulphated hyaluronic acids.

Sulphated hyaluronic acids having a sulphation degree of 3.5 per disaccharide unit, HyalS3.5, were prepared with different molecular weights corresponding to 21 x 10(3), 320 x 10(3) and 3500 x 10(3). The thrombin inhibition in plasma and in the presence of purified molecules, i.e. fibrinogen, antithrombin III (AT III) and heparin cofactor II (HC II), were studied for the three different MW compounds at different concentrations. The thrombin time in plasma depended on the length of the chain, and the two lower MW HyalS3.5 inhibited thrombin both by direct aspecific interaction and via HC II, whereas the activity of the highest MW compound was mainly related to the electrostatic interaction with HC II. The inactivation of FXa serine protease was only attributed to HyalS3.5-AT III complex.

Antithrombin III↗
PubMedDate not supplied

Surgical management of the hand in Apert syndrome.

In patients with Apert syndrome, the hands demonstrate many disturbances of soft tissue and bony structures. These include a short thumb with radial clinodactyly, complex syndactyly with a bony fusion involving the index, long and ring fingers, symphalangism and simple syndactyly of the fourth web space. The soft tissue anomalies involve the intrinsic muscles, the extrinsic tendon insertions and the neurovascular bundles. We have reviewed 52 patients who underwent surgical reconstruction of their hands. The aim of this study is to propose a better surgical management in the light of recent publications and to improve our understanding of the syndrome, attempting to reduce the number of procedures and to select the best possible procedures for each patient.

Acrocephalosyndactylia↗
PubMedDate not supplied

Mechanical complications in shunts.

A retrospective study was conducted on 1,719 hydrocephalic patients, treated between 1974 and 1983 at the Hospital for Sick Children (Toronto) and l'Hôpital des Enfants Malades (Paris), in order to better understand shunt failure. The statistical analysis demonstrates the following: (1) A probability of occurrence of shunt malfunction of 81% at 12 years of follow-up. (2) A high prevalence of shunt obstruction (56.1% of all malfunction) and fracture or disconnection of the tubings (13.6%). (3) A higher risk of proximal occlusion with flanged ventricular catheter. (4) Less malfunction with proximal-non-slit valves as compared to distal-slit valves. (5) The importance of pressure-flow characteristics of the shunt; because of an indirect relation between overdrainage and proximal occlusion. (6) A correlation between connectors and migration or fracture of the shunt. (7) Less distal obstructions when an open-ended distal-catheter was used. These complications were of some clinical, psychological and economical consequences. Their rate could be lowed.

Cerebrospinal Fluid Shunts↗
PubMedDate not supplied

A craniometric study of bicoronal craniosynostosis (BCC).

We compared 20 cases of bicoronal craniosyntosis (BCC) using the linear and angular values of the normal statistical material for the same age and sex. The skull in BCC is significantly shortened and flattened but with normal width. The height of the frontal arch (FNBR) is significantly decreased. The base of the skull is depressed with angle AB2 significantly increased, and angle NTNO significantly decreased and, even in some cases, with negative angular values. This is inducing a sinking of LEA (length from N to T), and in some cases LEA is lower than the line LNO (distance from N to O). The cephalic index (CI) was significantly increased, and the calculated cranial capacity (CC) was significantly decreased. Bregma (BR) is moving anteriorly in BCC, inducing an anterior movement of the calvaria with a bulge around BR. In this anterior movement we designate lack of positive occipital rotation. In BCC there is an evident lack of positive occipital rotation. Superimposing our drawings on the reference line NBA, we found for the first time a movement of anatomical landmarks similar to that observed in the negative occipital rotation in vestibular orientation.

Cephalometry↗
PubMedDate not supplied

A craniometric study of sagittal craniosynostosis (SC).

Twenty cases of sagittal craniosynostosis (SC) were compared with the linear and angular values of the normal statistical material for the same age and sex. There were significantly increased values of the length of the skull (LI) and the height of the frontal arch (FNBR) and significantly decreased width (WI) and height of the skull (HI) as well as the depth of the cerebellar fossa (PEP). The length of the anterior cerebral fossa (LEA) remained within normal limits and the distance BRPI between bregma (BR) and the internal protuberance (PI) was within normal limits or increased. The angular value of the basal angle (angle NT-BA, AB2) decreased significantly and the angle NTNO (angle between the lines NT and NO) and the angle BRTPI (the angle between the lines TBR and TPI) were significantly increased. The cephalic index (CI) was significantly decreased. The cranial capacity (CC) is normal or decreased. There is demonstrated an occipital over-rotation of the skull.

Cephalometry↗