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J P Chirossel

Publications and source records attributed to J P Chirossel.

At least 19 recordsLinked to original sources
PubMed2001

Clinical results of percutaneous pelvic surgery. Computer assisted surgery using ultrasound compared to standard fluoroscopy.

This study presents early results of clinical experience with the application of Computer Assisted Surgery (CAS) to percutaneous iliosacral screwing, with comparison to a historical series of patients treated using percutaneous fluoroscopy. Four patients were instrumented using a CAS system, with 10 screws being inserted. Thirty patients were treated by percutaneous fluoroscopic screwing, with 51 screws being inserted. The follow-up assessment included the following criteria; operative time, parameters of radiation exposure, neurological examination, screw placement evaluation on CT-scan, antalgic drug consumption, pain, Majeed grading, and loosening of implants. In the CAS group, the average radiation time was 0.35 min per patient and 0.14 min per screw. No trajectories outside the bone and no postoperative neurological deficits were found. In the fluoroscopic group, the average radiation time was 1.03 min per patient and 0.6 min per screw. Twelve screws had outside-bone trajectories, and iatrogenic neurological deficits were found in seven patients. The average operative time was 50 min in the CAS group and 35 min in the fluoroscopic group. The present CAS technique shows better placement of iliosacral screws, with no outside-bone trajectories and lower radiation exposure.

Adult↗
PubMed2001

[Computer-assisted video-endoscopic endonasal surgery].

UNLABELLED: To make the surgical procedure safer and more precise in FESS, a non-invasive markerless computer-assisted system (CAS) is described for intra-operative navigation whenever the critical regions may be affected by surgical manipulation. PATIENTS AND METHODS: Twenty patients with benign diseases of the paranasal sinuses were treated by Computer Assisted Video-endoscopic surgery, between December 1997 and March 1998. For the determination of accuracy and reproducibility of the system, ten anatomical landmarks on each side of the paranasal sinuses were chosen and measured. All of these points were identified on the direct live video-endoscopy image and compared to those obtained with the Optical Digitizing System (Flashpoint 5000(R)), on axial, coronal and sagittal view. The Optical Localizer we used detects the position of the relative coordinates of two rigid bodies made of IR-LED's each, one rigid body is secured to the head' of the patient with a headset, so that patient motion can be tracked, and the second rigid body attached to the operating instrument, leading to direct localization of the tip of the instrument. We use a markerless, skin surface-based registration method, which has the advantage to avoid doing a second CT scan examination usually performed to process the position of the fiducial markers. We register the data from the patient's usual paranasal CT scan. RESULTS: Computer-assisted surgery does not increase significantly the duration of the operation. Our markerless skin surface points registration method is reliable enabling of the movements patient's head during the procedure. Computer assistance can be used in almost any type of endoscopic sinonasal procedure. We obtained a registration and calibration accuracy of less than 1.5 mm in 89.2% of cases. CONCLUSION: CAS enables the surgeon to have a more thorough understanding of the complicated anatomy of paranasal sinuses, and may be especially helpful in revision surgery when normal anatomic landmarks are lacking. Due to the passive optical technology (Passive Polaris(R)), we are continuing clinical studies in ENT surgery in order do improve the system and to simplify its current management.

Adult↗
PubMed2001

Clinical validation of computer assisted pelvic surgery using ultrasound. A percutaneous safe technique with low radiation exposure.

This study presents early results of the clinical experience of computer assisted surgery (CAS) applied to percutaneous iliosacral screwing. The results of these 10 first cases (4 patients) are compared to an historical series of 51 cases (30 patients). The CAS technique shows better screw placement without outside bone screw and a very low radiation exposure.

Adolescent↗
PubMed2000

Management of craniocervical junction dislocation.

The discovery of a craniocervical junction malformation requires management in three steps: (1) The patterns must be recognized using tomographic measurements (Chamberlain's line, Wackenheim's line). Dynamic flexion-extension studies are necessary to assess stability or instability. Stable patterns range from platybasia to basilar invagination, with gradual deformation, and are frequently associated with Chiari malformation. Unstable patterns characterized by odontoid instability are the equivalent of an odontoid fracture. The origin is malformative (hypoplasia, aplasia of the dens, os odontoidum), but the last may be difficult to distinguish from an old odontoid fracture. They are found in many syndromes (Down, Morquio, etc.). Unstable atlantoaxial patterns with atlas assimilation are hardly reducible; they evolve toward progressive instability. (2) The neurological consequences must be defined from the clinical features of the spinal cord and the cranial nerves. Both static and dynamic MRI scans must be performed; in this way identification of the neural abnormalities (hydromyelia, Chiari, etc.) and of the osseous compression is possible. (3) The most appropriate operative procedure must be selected: stable platybasia with a nervous compression by Chiari is cured only by posterior decompression; odontoid instability is cured by reduction and posterior fixation, using hooks and autologous bone grafts on the posterior arches of C-1 and C-2. Sometimes a transarticular screw fixation of C1-2 is necessary if there is a defect on the C-1 posterior arch. Craniocervical dislocations with assimilation of the atlas require posterior occipito-vertebral bony fixation with grafts and external halo immobilization or internal fixation with hooks or screws, with anterior transoral decompression in a second step.

Arnold-Chiari Malformation↗
PubMed1999

Elastic reinforcement and thickness of the joint capsules of the lower cervical spine.

Mechanical studies have shown the major strength of the joint capsules of the lower cervical spine, especially in its ventrolateral part. The aim of this study was to examine the structure of the joint capsules in order to discover if there is a correspondence between biomechanical properties and descriptive anatomy. Ten transverse sections and 4 sagittal sections obtained from 6 cadavers were observed under light microscopy at X 25 to X 250 magnification. Standard stains and specific elastic fiber stain were used for histologic preparation. The data were the thickness of the joint capsules in the different quadrants, and the topography and direction of the elastic fibers. The results showed that the ventrolateral part of the joint capsules is thick and reinforced by oblique elastic fibers. The dorsal part is thin. The authors suggest that the descriptive anatomy of the joint capsules confirms their mechanical properties. They note that the role of the ventrolateral part is supplemented by that of the posterior longitudinal ligament for the stability of the functional cervical spinal unit.

Aged↗
PubMed1998

Percutaneous iliosacral screw placement using image guided techniques.

A computer assisted technique of iliosacral screw placement that is applicable to unstable pelvic ring fractures is proposed. The goals are to operate noninvasively with a percutaneous procedure to decrease the complications of surgical exposure and to provide greater accuracy in locating the close neurovascular structures. Preoperative computed tomographic images of the pelvis are provided and a computed tomography three-dimensional model is built. In this model, the optimal trajectories for the drilling are planned. An ultrasound based registration is performed intraoperatively. This registration is the most original part of this work. After performing the passive drilling guidance step, the surgeon places the screws. The accuracy of the ultrasound based registration is checked by comparison with a standard surface based registration at the end of the test experiment. Each screw position is verified by a computed tomographic examination. Four human anatomic specimen pelves were tested with three screw insertions for each pelvis (12 screws). All of the screws were considered to be placed correctly. The method is safe and encourages the start of clinical application.

Bone Screws↗
PubMed1998

[Unusual approaches to hypophyseal adenomas].

For pituitary adenomas surgery, rhinoseptal transsphenoidal approach is used in 98 to 99% of the cases. Although this approach is fitting for microadenomas and the majority of macroadenomas, some of them develop extensions in the nasal fossas, the posterior cranial fossa, the suprasellar region, or into the cavernous sinus and will require other approaches. For the superior routes, the frontopterional approach gives good control of the suprasellar region, the anterior and middle base of the skull. The tumor dissection is performed inside the concavity of the chiasm and between the internal carotid artery and the optic nerve (optico-carotid approach). The frontopterional approach is used for superolateral extensions, especially in the lateral fissure. The bifrontal basal inter hemispheric approach, through a medial frontal bone flap tangential to the base, gives a good route to the suprasellar region and behind the dorsum, and also for tumors extended in the third ventricle in case of prefixed chiasm. For the inferior routes, the participation of ENT or craniofacial surgeons is a great help. The transfacial or transethmoidal approach performs a hollowing of the nasal fossas and gives a large interorbital tunnel adapted for tumors extended in the rhinopharynx and the ethmoid. The Le Fort I maxillary osteotomy offers also a large approach for adenomas extending in the rhinopharynx. The transcavernous approach from Dolenc, for adenomas progressing in the cavernous sinus requires a long and difficult procedure. The progression of some adenomas in many directions may require a combined approach in one or two procedures.

Adenoma↗
PubMed1996

Severe head injuries: an outcome prediction and survival analysis.

OBJECTIVE: To identify the predictors determined early after admission and associated with unfavorable outcome or early (within 48 h) death after severe head injury. DESIGN: Prospective cohort study. SETTING: A neurosurgical intensive care unit in a university hospital. PATIENTS: 198 consecutive comatose patients hospitalized from 1989 to 1992. RESULTS: Logistic regression showed that a combination of age, best motor response score from the Glasgow Coma Scale, and hypoxia provided a good prediction model of unfavorable outcome (sensitivity = 0.93). The length of participation of survivors was 6 to 61 months (median 27.1). The Cox model demonstrated age, motor score less than 3, mydriasis, and hypoxia as poor prognosis factors. CONCLUSIONS: Clinicians can determine the odds of a good outcome from the combination of three easily measurable factors using a simple diagram constructed from logistic regression. Survival analysis showed that motor score adjusted values greater than 3 had the same prognosis.

Adult↗
PubMed1996

Femoral neuralgia due to degenerative spinal disease. A retrospective clinical and radio-anatomical study of one hundred cases.

We report a study of 100 patients admitted to the Grenoble Regional Teaching Hospital between July 1985 and February 1994 for femoral neuralgia due to degenerative spinal disease. A herniated disk resulting in nerve root impingement was found in 79 patients (83 herniated disks) and lumbar spinal stenosis in 21. The level of nerve root compromise was L2-L3 in eight cases, L3-L4 in 35 cases, and L4-L5 in 40 cases. Herniated disks were divided into several groups based on their location with regard to the intervertebral foramen: posterolateral herniations were entirely contained within the spinal canal (n = 12; 14.5%), whereas far lateral, or foraminal, herniations (n = 71; 85.5%) involved the intervertebral foramen. Twenty-nine foraminal herniations (34.9%) had a component located within the spinal canal (medioforaminal herniations), 33 (39.8%) were entirely contained within the foramen (pure foraminal herniations), and nine (10.8%) were located lateral to the foramen (lateroforaminal herniations). As compared with posterolateral herniations, foraminal herniations were associated with shorter symptom duration at admission (p < 0.05), a greater likelihood of nocturnal exacerbation of pain (p < 0.001) and of a positive femoral stretch test (p < 0.01), and failure of the pain to worsen during Valsalva maneuvers (p < 0.01).

Adult↗
PubMed1996

When is spinal fusion warranted in degenerative lumbar spinal stenosis?

This study, conducted by a group of neurosurgeons who devote a large portion of their professional time to the treatment of degenerative lumbar spine lesions, was prompted by the dramatic increase in the number of lumbar spinal fusion procedures performed over the last few years in a broad spectrum of disorders ranging from chronic incapacitating low back pain to lumbar spinal stenosis. In the authors' experience, lumbar spinal fusion is rarely warranted and often of dubious efficacy. To investigate this contradiction, the authors reviewed the medical literature on lumbar spinal fusion for the treatment of degenerative spinal stenosis. They have defined lumbar instability as objectively as possible, reviewed clinical and roentgenographic features, described spinal fusion techniques with the drawbacks of each, and evaluated outcomes of surgery for degenerative lumbar spinal stenosis with or without fusion. Findings demonstrate that spinal fusion is a technique of unproven benefit that should be used only in carefully selected patients until results of reliable, prospective, comparative clinical trials become available. In the authors' opinion lumbar spinal fusion should be used as the first-line treatment only in young patients with clinical manifestations directly related to lumbar instability as defined in this study, when decompression requires removal of both facet joints and of the disk (which is rarely the case) or when simple decompression is followed by a recurrence of symptoms ascribable to worsening vertebral slippage.

Adult↗
PubMed1995

Percutaneous intradiscal radio-frequency thermocoagulation. A cadaveric study.

STUDY DESIGN: This study examined the effect of radio-frequency thermocoagulation on cadaveric disc material. Radio-frequency lesions are induced to decompress the nerve root by coagulating the nucleus pulposus. OBJECTIVES: The purpose of this study was to assess the potential of the radio-frequency lesion technique for treating lumbar disc herniation percutaneously. The effect of radio-frequency thermocoagulation on cadaveric disc material was studied. SUMMARY OF BACKGROUND DATA: An intradiscal bipolar electrode is used for the thermocoagulation of the nucleus pulposus. METHODS: Lumbar discs of 27 adult cadavers were used for the experiments within 72 hours of donors' deaths. The physical and thermal parameters of intradiscal radio-frequency thermocoagulation were determined experimentally. Acute macroscopic and histologic changes before and after thermocoagulation were investigated. The temperature distribution of the tissue surrounding the disc was measured during the operation using thermocouples to evaluate potential heat damage. Also, computed tomography and magnetic resonance imaging of the disc were performed before and after thermocoagulation. RESULTS: Macroscopic observation showed that the lesion induced by radio-frequency thermocoagulation is homogeneous and intense without necrosis, and is limited to the nucleus pulposus. Histologically, the endplates and vertebral bodies were unaffected and an architectural disorganization of the stroma of the nucleus pulposus was seen. The temperature increase of the tissue surrounding the discs did not exceed 3-4 C. CONCLUSION: A bipolar electrode and a radio-frequency alternating current permits percutaneous intradiscal thermocoagulation for destruction of a portion of disc material in a cadaveric spine.

Adult↗
PubMed1995

Blood supply of the olfactory nerve. Meningeal relationships and surgical relevance.

The authors report the results of a series of dissections and anatomic sections of the fronto-basal region of the brain and of the anterior cranial fossa in human cadavers. The constant presence of an arachnoidal cistern above the olfactory nerve was verified. The arachnoid separates from the pial membrane and forms a bridge with the ventral part of the olfactory bulb and tract, from the lateral edge of the olfactory sulcus to the medial edge of the gyrus rectus. The cistern is wide in its anterior portion, between the gyrus rectus and the olfactory bulb, and is reduced to a virtual slit in its posterior portion where the tract is lodged in the olfactory sulcus. The olfactory nerve can be separated without damaging fronto-basal arachnoidial adhesions over several centimeters. Dissection of this region after intravascular injection of colored media shows the constant presence of an artery destined to the olfactory bulb and tract. It originates either from the lateral surface of the anterior cerebral a. (segment A2), or from the medial fronto-basal a., and consistently provides terminal branches in front of the olfactory trigone in the medial olfactory sulcus. At their ventral extremity, the olfactory structures are therefore vascularised independently for several centimeters, from the lower face of the frontal lobe. The independent vascularisation of the olfactory nerve, the tenuous and easily detachable adhesions, and the actual presence of a true arachnoidal cistern all contribute to enabling surgical techniques which conserve olfactory function during anterior approaches.

Arachnoid↗
PubMed1993

[Corneatopic evaluation in the trigeminal ganglion of the rat].

Cornea is only innervated by free nerve endings. A corneal scarification exposes free nerve endings which are able to transport True Blue and Fast Blue dyes by retrograde axonal transport. These tracers label the perikaryon. A few days later, the rats are sacrificed and perfused with an intra cardiac 10% formaldehyde perfusion in a phosphate buffer. The analysis of ipsilateral semi lunar (trigeminal) ganglion with a Leitz Dialux fluorescence Microscope shows fluorescent blue cells. The organization of these cells in the volume of the ganglion has been determined by selective labelling of each corneotopic zone in the supero-internal quarter of the rat trigeminal ganglion. Data from the literature about the somatotopic organisation of the other parts of the rat face are in agreement with these results.

Animals↗
PubMed1993

[Evaluation of dermatomes in the hind paw of the rat using retrograde axonal transport].

UV light fluorescent tracers (True Blue and Fast Blue) are placed in contact with sensitive receptors after dermabrasion. The abraded surfaces are limited to two hemidorsal areas and two hemi plantar areas on the animals' foot. A five days survival is allowed to enable the axonal retrograde transport of the tracers, then the animals are sacrificed and perfused with an intracardiac injection of 10% formaldehyde in phosphate buffer at 7.4 pH. The lumbar spinal ganglions are immediately dissected out, examined as a whole with a Leitz Dialux fluorescence microscope, then frozen and cut with a cryotome. The results of this analysis show that: i-only ipsilateral dorsal root ganglions are labeled by blue dye. ii-the number of fluorescent cells varies between 20 to 60 per ganglion. iii-a map of the distribution of the dermatomes on the rat hind foot can be deducted from the study of the labelled ganglions. They spread from L2 to L5 from the cranial to the caudal part, and from the medial to the lateral side of the rat foot, on both dorsal and plantar areas.

Amidines↗