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Biomedical subjects

Y Kéravel

Publications and source records attributed to Y Kéravel.

10 recordsLinked to original sources
PubMed2000

A new device for endoscopic third ventriculostomy.

Since its description by Dandy in 1922, several techniques have been used to perform third ventriculostomy under endoscopic control. Except for the blunt technique, in which the endoscope is used by itself to create the opening in the floor of the third ventricle, the other techniques require more than one instrument to perforate the floor of the ventricle and enlarge the ventriculostomy. The new device described is a sterilizable modified forceps that allows both the opening of the floor and the enlargement of the ventriculostomy in a simple and effective way. The new device has the following characteristics: 1) the tip of the forceps is thin enough to allow the easy perforation of the floor of the ventricle; 2) the inner surface of the jaws is smooth to avoid catching vessels of the basal cistern; and 3) the outer surface of the jaws has indentations that catch the edges of the opening to prevent them from slipping along the instrument's jaws. The ventricle floor is opened by gentle pressure of the forceps, which is slowly opened so that the edges of the aperture are caught by the distal outer indentation of the jaws, leading to an approximately 4-mm opening of the floor. This device has been used successfully in 10 consecutive patients. This new device allows surgeons to perform third ventriculostomy under endoscopic control in a very simple, quick, and effective way, avoiding the need for additional single-use instruments.

Endoscopes↗
PubMed1998

Endoscopic management of colloid cysts.

OBJECTIVE: Several surgical approaches have been proposed for the treatment of colloid cysts, which still remains controversial. The most recent technique used is endoscopy. By its nature, endoscopy cannot offer complete removal, as compared to microsurgical techniques, but can do more than puncture. To evaluate the usefulness of endoscopy for colloid cyst surgery, a series of 15 patients who were operated on for colloid cysts under endoscopic control since 1994 was reviewed. METHODS: The presenting symptoms of our patients (10 men and 5 women) were intermittent headache (10 patients), nausea (3 patients), short-term memory loss (4 patients), coma (2 patients), gait disturbance (3 patients), blurred vision (2 patients), and mental status changes (3 patients). The sizes of the cysts ranged from 4 to 50 mm (median, 22.93 mm). Depending on the radiological appearance, the procedure was performed via a right (10 patients) or left (5 patients) precoronal burr hole. A rigid neuroendoscope was used. Initial stereotactic placement of the neuroendoscope was used in two patients who had moderate hydrocephalus. In the other patients, hand-guided endoscopy was performed using an articulated arm. The cysts were perforated with a needle. The opening was enlarged with microscissors. The cyst material was aspirated, and the remaining capsule was coagulated. RESULTS: The average follow-up was 15.26 months (range, 1-28 mo). Total aspiration of the cysts was achieved in 12 patients, as revealed by normal postoperative magnetic resonance imaging. Control magnetic resonance imaging revealed residual cysts in three patients. One patient presented with an asymptomatic recurrence at 1 year. Resolution of the symptoms was obtained in all patients except for two of the four patients with preoperative memory deficit (improvement without complete recovery). There was no mortality or morbidity. CONCLUSION: These results show that endoscopy is a safe and promising percutaneous technique for the treatment of colloid cysts of the third ventricle. Longer follow-up is, however, still required.

Adult↗
PubMed1998

[Peripheral neurotomy in the treatment of spasticity. Indications, techniques and results in the lower limbs].

INTRODUCTION: The aim of this study was to review the principle of peripheral neurotomy for the treatment of lower limb spasticity. The importance of clinical assessment is stressed (with particular focus on motor block) for determining the best surgical indications. MATERIAL AND METHOD: Between 1989 and 1997, 392 neurotomies were performed in 277 patients in the neurosurgery department of the Henri Mondor Hospital, Créteil, France. Surgical technique consisted in partial and segmental resection, involving each motor collateral branch of muscles with excessive spasticity. For the lower limb, the most frequent neurotomy was performed on collateral branches of the posterior tibial nerve (66%) for the spastic foot. RESULTS: Preoperative motor block provided the advantage of "mimicking" the effect of the neurotomy and therefore gave the patients an idea of the expected result of surgery. For the spastic foot, posterior neurotomy led to the disappearance of ankle clonus in all patients. When antagonist muscles were present, splints were no longer needed after neurotomy. Cinematic analysis showed that tibial neurotomy improved angular variations of the second rocker of the ankle during stance. CONCLUSION: Peripheral neurotomies are simple and safe procedures for the treatment of lower limb spasticity and should be routinely used in general neurosurgery practice.

Adolescent↗
PubMed1998

[Treatment of spasticity with injections of botulinum toxin. Review of the literature].

Botulinum toxin injections are a new treatment for limb spasticity. Intramuscular injections can be performed in spastic muscles; efficacy occurs one or two weeks later, with a mean duration of three months. Clinical action is related to chemical denervation of presynaptic motor end nerves by the botulinum toxin. Double blind studies versus placebo have demonstrated the improvement of limb spasticity after injections of botulinum toxin. Ashworth scales, articular angulations, pain and spasms improve both in upper and lower limb spasticity. Functional scores are not changed in the upper limb, but quality of life improves. Kinematic parameters of gait are improved in lower limb spasticity, especially in children with cerebral palsy disorders. There were no reports of serious side effects. Botulinum toxin is a safe and effective treatment of localized spasticity in adults and children.

Animals↗
PubMed1997

Peripheral selective neurotomy of the brachial plexus collateral branches for treatment of the spastic shoulder: anatomical study and clinical results in five patients.

A new type of peripheral selective neurotomy involving the collateral branches of the brachial plexus has been perfected for treatment of the spastic shoulder. Anatomical study of six cadaveric shoulders led to the specification of a surgical approach to the pectoralis major and teres major nerves, which innervate the main muscles implicated in shoulder spasticity. Between August 1994 and September 1995, five patients (four men and one woman) underwent two to four associated neurotomies of the upper limb, which included neurotomies of the pectoralis major (all five patients) and the teres major (two patients). The average follow-up period was 11 months, during which there were no local or general complications. The spasticity of the treated muscles resolved in all five patients (Held score range 3-0). The neurotomies led to statistically significant average amplitude increases in shoulder mobility, especially in abduction (+30 degrees), antepulsion (+50 degrees), retropulsion (+20 degrees), and external rotation (+20 degrees). The functionally useful active amplitude scores increased from 2.66 to 5.16/6. This functional improvements mainly involved the standing position and walking stability, as well as improvement in the range of motion of the lower limb. These results encourage the increasing use of this new type of neurotomy in treatment of the spastic upper limb.

Adult↗
PubMed1994

[Neurosurgical endoscopy. Diagnostic and therapeutic indications].

An historical review of neurosurgical endoscopy is evocated. The characteristics of the endoscopic material are discussed: flexible or rigid?, length?, diameter?, irrigation?, free-hand manipulation or fixed arm? A rigid neurosurgical endoscope (STORZ) is described which characteristics are the following: 5 mm/3.7 mm ovale diameter, working length of 21 cm (allowing its use under stereotactic conditions), 5F working channel and articulated arm for solid immobilization in the desired position. All the indications of endoscopy are described and illustrated with a series of 48 patients. Indications for diagnosis are rare and summarised in exceptional help for conventional surgery. 80% of the usual indications of endoscopy were represented by third ventriculostomy. The endoscopic guidance brings safety and allows an increasing of the ventriculostomy's indications. Endoscopic fenestrations of arachnoid cyst are described with a particular interest on suprasellar cysts. The other indications are rare: unilateral hydrocephalus, biopsies of intraventricular tumors, puncture of colloid cysts.

Brain Diseases↗
PubMed1988

[Writer's cramp and left frontal meningioma].

A 55 year-old, right-handed, man developed a progressive writer's cramp spreading to a right hemidystonia. He had a left paramedian frontal meningioma. The association of an hemidystonia with contralateral lesions in the basal ganglia has been often reported. Its occurrence with a frontal lesion appear to be much less frequent. This association suggests a possible disorder of frontostriatal connections.

Dystonia↗
PubMed1975

[Treatment of arteriovenous fistulas and of aneurysms using an inflatable and releasable balloon. Experimental principles. Application to man].

The authors have perfected a technique making possible the percutaneous introduction of a balloon filled with hydrosoluble iodine and releasable, either in an arteriovenous fistula or in an aneurysm. Experimental jugulo-carotid fistulae and experimental aneurysms in the dog were treated in this way. The technique has been used in two human patients - one with a traumatic caverno-carotid fistula and the other with a complicated vertebral fistula.

Adult↗