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Biomedical subjects

W Pellet

Publications and source records attributed to W Pellet.

At least 55 records · Page 3Linked to original sources
PubMed1995

Pneumocephalus after thoracotomy.

BACKGROUND: Pneumocephalus is a well-known phenomenon in which a fistula between the thoracic cavity and the subarachnoid space is one of its rare etiologies. METHODS: We report a new case of pneumocephalus after thoracotomy and review eight similar cases in the literature. RESULTS: In all cases, an operation was carried out for an intrathoracic neoplasm located at the apex with chest wall invasion. In the presence of symptoms, the diagnosis of pneumocephalus and identification of the subarachnoid pleural fistula were differently supplied by radiographic and isotopic exams. In the follow-up, one patient was affected by meningitis and two patients died. CONCLUSIONS: The occurrence of pneumocephalus must be considered when neurologic problems emerge after thoracotomy. It appears that if conservative treatment fails, surgical closure of the fistula via thoracic or neurosurgical approach is indicated.

Aged↗
PubMed1995

Role of magnetic resonance imaging in predicting late facial motor function after removal of vestibular schwannomas by the translabyrinthine approach.

Facial motor function was assessed in 61 patients 18 months after surgical resection, by the translabyrinthine approach, of vestibular schwannoma involving both the cerebellopontine angle (CPA) and the auditory canal. Pre-operative magnetic resonance imaging (MRI) was performed to measure the maximum extracanalicular diameter of the tumour between the porus and the farthest extension in the CPA on transverse slices and to calculate extracanalicular tumour volume. Post-operative facial motor function was graded according to the House and Brackmann system. There was a statistically significant relationship between late facial motor function and extracanalicular diameter. The best cut-off point for good and poor results was 20mm. There was no relationship between the tumour volume and the late post-operative facial motor function grade. In this study the best pre-operative radiological predictor of the late facial motor function in patients operated on by the translabyrinthine approach was the maximum diameter measured by MRI.

Adult↗
PubMed1995

[Chondrosarcoma of the skull base. Apropos of sphenotemporal localization and review of the literature].

The authors report a case of chondrosarcoma of the skull base with a myxoïd histology, developed from the right sphenotemporal junction. Twenty six months after enlarged tumour removal, there are no clinical or neuroradiological signs of recurrence. A review of the 180 published cases emphasizes the rarity of this tumour originating of the skull base synchondrosis and occurring in young patients. MRI forms the basis of the topographic work-up but does not formally distinguish it from chordoma. Diagnosis is confirmed by histology which establishes a prognostic scale. Immunohistochemistry eliminates chondroïd chordoma by demonstrating a mesenchymatous phenotype. Only enlarged tumour removal can prolong survival even though improvements have been made in high energy radiation therapy and radiosurgery. Cases of recurrence or rare metastasis are probably due to incomplete exeresis and in most cases linked to high grade histology tumours.

Chondrosarcoma↗
PubMed1994

Tissue-specific expression and methylation of the human CYP2E1 gene.

The level and number of CYP2E1 gene transcripts were investigated by northern blot analysis in various human adult tissues including liver, lung, placenta, skin and neurinoma. Three transcripts of 1.8, 2.6 and 4 Kb were expressed in a tissue-specific manner. The origin of the various transcripts was studied and showed that both 4 and 2.6 Kb mRNAs contained sequences from the 3' non-translated region of the gene and that the 4 Kb also contained region localized in the 5' non-translated region. Furthermore, it clearly appeared that a catalytically active CYP2E1 enzyme (as proved by NDMA demethylase activity) was only detected in tissues expressing the 1.8 Kb. The human CYP2E1 was also identified through immunohistochemical techniques. Finally, we observed a relation between the hypomethylation of the human CYP2E1 gene and the hypoexpression of the corresponding protein.

Base Sequence↗
PubMed1994

[An unusual cervical tumor: meningioma. Apropos of a case of petrous origin. Review of the literature of meningioma presenting as cervical mass].

Primary ectopic meningiomas are uncommon. The authors report a case of a 12-year-old boy with a meningioma presenting as a neck mass. The conclusion of the initial biopsy was chemodectoma, but on surgical resection, the tumour was found to have invaded the petrous bone. Post-operative follow-up was uneventful but magnetic resonance imagery revealed extension to the cerebello-pontine angle, the cavernous sinus, the tentorium and the falx. The authors discuss the main pathogenic hypotheses and the classification of ectopic meningiomas. Based on 62 similar cases reported in the literature, primary ectopic meningiomas are found most often in young subjects, with no female predominance, neurofibromatosis is often observed and angioblastic or malignant features are frequent. These tumours can be divided into 6 localizations (jugulo-carotid space, lymph nodes, parotid gland, thyroid gland, soft paravertebral tissues, skin) and into 3 pathogenic groups (solitary ectopic tumour of the neck, tumour of the neck connected to a cranial or spinal meningioma, metastasis). Meningioma of the jugulo-carotid space with connection to the skull base is the most frequent entity. Solitary ectopic meningiomas of the neck occur in only 1 out of 5 cases. In 2 out of 3 cases, the neck localization involves a connection to a cranial or spinal meningioma. In a few cases the neck mass is a metastasis. These findings suggest that a complete neuroradiological work-up is required. Prognosis depends on the completeness of the surgical resection and the histologic aggressiveness frequently encountered.

Child↗
PubMed1993

Correlation between cytogenetic and histopathological findings in 75 human meningiomas.

The correlations between cytogenetic and histopathological findings were analyzed in 75 human meningiomas. The tumors were classified according to increasing degrees of anaplasia into three grades: Grade I, benign; Grade II, atypical; Grade III, anaplastic. In 45 tumors of Grade I (benign), we more often observed a normal karyotype or monosomy 22. In 23 tumors of Grade II (atypical), we observed karyotypes with structural and/or numerical abnormalities with the presence of telomeric associations in 8 of them. These last tumors were fibroblastic. In seven Grade III tumors (anaplastic), we also observed complex abnormalities, and in one case, we observed telomeric associations. Our observations show that complex chromosome abnormalities and telomeric associations are observed in tumors that histologically display a certain degree of anaplasia. It is possible that the result of histopathological and cytogenetic correlations might represent a prognostic factor in meningiomas.

Adolescent↗
PubMed1993

[Secondary localizations of cerebral glioblastoma. Pathogenic and anatomoclinical focus apropos of a case of multiple bone metastases disclosed by vertebral involvement].

This report describes a case of a cerebral glioblastoma with multiple metastases appeared two years after craniotomy and revealed by a diffuse vertebral involvement with a lumbo-sciatic pain. The experimental and clinical data from the literature about distant localizations of glioblastoma give the arguments for the rarity and the pathogenic modes of the natural course. The distant localizations of cerebral glioblastoma, identified by immunohistochemical staining for glial fibrillary acidic protein, occurred in young patients, late in the follow-up which the duration is longer than those of classical glioblastomas; their occurrence hasten the disease course. Two distinct oncological entities might be identified: metastases, using blood or lymphatic pathways, commonly from a supra-tentorial primary tumor, are facilitated by surgical treatment; their exclusive extraneural sites are usually symptomatic; grafts, by seeding via cerebrospinal fluid pathways, are spontaneous or facilitated by tumoral removal and are disseminated along the neuraxis; they occur frequently and are usually asymptomatic; when shunts induce them, it gives rise to symptomatic peritoneal seeding; they seem to concern poor invading primary glioblastomas. The extraneural (metastasis) or neuraxial (graft) sites and the ways of occurrence (spontaneous, or facilitated by craniotomy or induced by surgical shunts) allow to classify the distant localizations of glioblastoma in six pathogenic types.

Bone Neoplasms↗
PubMed1993

[Tuberculous spondylodiscitis. Diagnostic elements and value of MRI. Apropos of a cervical localization].

The authors report a case of tuberculous spondylodiscitis with an intracanalar ant retropharyngeal involvement. This pathology is recently increasing like the immunodeficiency syndromes. Cervical tissue compression and neurological signs are the main clinical findings. Among the radiological explorations of disco-vertebral infections, the value of MRI study is now admitted. Using of T1 and T2 weighted sequences and Gadolinium injection provides the positive diagnosis, and well visualizes the extent: low signal of vertebral body, decrease and low signal of discal space, prevertebral and retrovertebral enlargement with a low signal intensity of the abscess in T1 weighted sequence and enhancement following Gd-DTPA administration; high signal intensity of vertebral body, prevertebral and epidural masses and abscess in T2 weighted sequence. The authors describe the evolutive features of Pott's disease and the value of MRI in the post-therapeutic course: T1-signal increases while enhancement following Gd-DTPA administration decreases and T2-signal decreases. The differential diagnosis with chordomas, metastasis, and pyogenic spondylodiscitis is well assessed by MRI.

Cervical Vertebrae↗
PubMed1993

[Enlarged trans-temporal crania fossa approach. Technique and indications].

The authors report their experience using an enlarged middle cranial fossa approach for the removal of 33 acoustic neurinomas and 10 cerebellopontine angle meningiomas. The Technique is defined. This approach proved suitable for stage I neurinomas, ensuring total removal in all 13 patients with stage I lesions, hearing conservation in 9 (69.2%) of these patients, grade 1 + 2 facial nerve function in 80% of patients and grade 3 function in 20% of patients. While total removal was always possible for stage II neurinomas, the functional results were poor with hearing conservation in only 3 of 15 patients (20%), grade 1 + 2 facial nerve function in 45% of patients and grade 3 function in 54% of patients. Total removal was possible in only 1 of 4 patients with stage III neurinomas. This approach proved excellent for cerebellopontine anale meningiomas, providing wide access to the tumor and protecting the acoustico-facial bundle situated behind the tumor. Among the 10 patients operated by this route, 8 had conservation of hearing and all 10 had normal facial motricity (grade I) at 3 months.

Hearing Disorders↗
PubMed1993

[Functional results of the surgery of unilateral acoustic neuroma].

The authors sent a circumstantial questionnaire to 224 surviving patients out of a 228 unilateral acoustic neurinoma operated on from June 83 to December 90 range of patients in order to assess their complaints. Seventy-two per cent of these neurinomas were Stade III or IV of Koos. Translabyrhintine approach was used for 85% and suprapetrous approach for 15%. The post-operative mortality rate is 1.75%. At the end of the procedure, the removal seemed total in 99% of cases and the anatomical facial nerve continuity was preserved in 94% of cases. Our patients kept or recovered a normal (Grade I of House--52%) or almost normal (Grade II of House--14%) facial motion in 66% of cases. A normal facial rest stretching with a complete eyelid closure but an asymmetrical facial mimic (Grade III of House) were in 20% of cases, and a more important facial palsy with incomplete eyelid closure was in 4% of cases (Grade IV of House). Patients needed an hypoglosso-facial anastomosis in 10% of cases. Always, this anastomosis restored a good facial motion near the Grade III of House. Hearing preservation was achieved for 45% of the attempts (through a suprapetrous approach) but hearing so preserved was functional (pure tone loss less than 50 db) in 37.5% of cases (5% of all the patients of this series) and only 61% of these patients kept or recovered a normal or almost normal facial motion. Varying, often regressive, complications were observed: C.S.F. leakages (7.5%) through the operative wound in two third of cases, owing to a pressure raising due to meningitis or C.S.F. circulatory constraint and usually cured by lumbar punctures and, if need be, antibiotics and, in one third of cases, through the tympanic cavity then nostril because of a hole remaining on the petrous drilled wall and usually needing a reintervention, swallowing difficulties (3%), due to a contralateral vagus nerve palsy in half of cases, postoperative hematomas (1.75%), fatal in one out of two times, brain traumatism (1.75%), meningitis (0.4%). The answers of patients were proper enough to be used for this study in 80% of cases (178). Their subjective answers about facial motion agreed with our objective assessment in 84% of cases that is emphasizing the difficulties of all attempt to this type of valuation. Our patients point out balance troubles in 67% of cases.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1992

[Giant cholesterol cysts of the petrous apex].

In connection with their two own cases, the authors deal about the giant cholesterol cysts of the petrous apex. The lesions which are to be differentiated from epidermoid cysts are cholesterol granulomas. Their petrous apex location explains their characteristic large appearance. As each cholesterol granuloma, they occur when a bony cell is obstructed. This chronic obstruction induces mucosal edema then bleedings which lead to the formation and, by the lack of drainage, to the accumulation of cholesterol crystals. These crystals initiate a non specific reaction to foreign bodies, a granuloma, which also can bleed. Thus, a continuous cycle perpetuates the growth of the lesion. This lesion, when it is localized in the petrous apex, can reach a big size before the appearance of some signs. Usually, these are otologic (sensorineural hearing loss, tinnitus, vertigo) and/or cranial nerve palsies (V, VI, VII). C.T. scan (well defined, sharply marginated bony expansible lesion with isodense to the brain central part) and M.R.I. (central region of increased intensity on both T1 and T2 weighted images and peripheral rim of markedly decreased signal intensity in all instances) features are characteristic enough to allow diagnose with other petrous apex lesions (cholesteatoma, mucocele, epithelial cyst, histiocytosis X, ...). Surgical treatment must try to evacuate and to aerate the cavity or perhaps to obliterate it with fatty pieces in order to prevent the recurrence.

Adult↗
PubMed1991

[Tumors of the cerebellopontine angle. Fortuitous association of meningioma and neurinoma].

The authors report the case of a totally accidental meningioma/neuroma association in the same internal auditory meatus, although no Recklinghausen's disease seems to be involved. In relation with this case and with the literature data, the authors review the frequency and diagnosis of meningiomas of the cerebellopontine angle. Lastly, this case helps avoiding a diagnostic error, since the imaging may lead to diagnose one tumor only.

Cerebellar Neoplasms↗
PubMed1991

[Aneurysmal temporal bone cyst. Apropos of 2 new cases].

Aneurysmal bone cyst is a well known lesion on the metaphyse of lung tubular bones or on the spine. Unusually, it is detected on the skull and more rarely again on the temporal bone. The authors, talking about the eleven cases they have found in the literature and two recent personal cases, try to describe the main diagnostic dates of this temporal lesion which one has never known if it is a real tumor or a reactional dystrophic pseudotumor secondary to an intrabone circulatory incident, perhaps a phlebitis. As for all other locations, these temporal bone forms are more frequently encountered among adolescents or young adults and, because their blowing bone effect, give clinical signs which directly result from their aggressive behavior on the surrounding structures, in this particular location: temporal fossa swelling, otologic, ophthalmologic or stomatologic symptoms, facial or trigeminal nerves troubles and rarely central neurological signs. On CT-scan, it appears as a space-occupying lesion located in the temporal fossa, with a blowing bone aspect, with intracranial and infratemporal expansions. This CT scan lesion is heterogeneous and contrast enhanced except in its center which is hypodense, as a cyst. The MRI shows comparable pictures. Its total excision, made easier by a preoperative embolization, gives a total and definitive recovery.

Adolescent↗
PubMed1991

[Screwing the odontoid process. A functional operation].

The authors describe a case of direct screw fixation of the odontoid process via an anterolateral retropharyngeal subhyoid pre-sternomastoid approach and discuss the indications for this operation. In this particular case, immobilization by a cervical collar or a halo vest was not chosen because of its constraining character and the risk of secondary displacement and pseudarthrosis. C1-C2 or occipitospinal arthrodesis, whether performed via a posterior, lateral or anterior approach, is difficult to perform and always leads to a functional handicap. The transoral approach does not allow direct screw fixation of the dens. Dens screwing via an anterior pre-sternomastoid subhyoid approach is the most logical and least disabling technique. The subhyoid approach is much simpler than the suprahyoid approach. This technique is used in fractures of the odontoid process with an ablique downward and backward fracture line, with or without arch fracture of C1, and allows screwing perpendicular to the fracture line. Considering the present results and the literature, the double screw fixation does not seem to be justified.

Adult↗
PubMed1990

[Results of surgery of acoustic neuroma via translabyrinth and suprapetrous approaches. Development of a classification by House and Brackmann based on facial function].

Two studies were conducted consecutively on two series of post-operative acoustic neurinoma patients. The first one included 104 patients over a period spanning from January 1982 through April 1986; the second one bore on 75 cases enrolled between October 1985 and April 1988. Post-operative complications, sequelae, and findings were analyzed. As far as facial function was concerned, this was assessed on the basis of a classification worked out by J.W. House and D.E. Brackmann. For the first series (93 patients tested, 86 followed up and 7 who completed and returned a form arranged from Brackmann's questionnaire), the following results were obtained: 94% with anatomically intact nerves, including 50.0% grade I; 8.6% grade II; 10.7% grade III; 12.8% grade IV; 4.3% grade V, and 2.2% grade VI cases. 10 nerve sections pertaining to grade III and grade IV surgical repair cases including 10 hypoglossofacial anatomoses were reported. In the second series, 75 patients were followed up for at least 2 years. The facial nerve condition was recorded at the end of the operation, corresponding to the beginning of the nerve recuperation period. A very tight relationship was noted between the nerve condition and the end result as reflected by facial function; such correlation was also found to exist between facial function and tumor size. Likewise, end-point facial function was strictly dependent upon the incipient recuperation phase, whenever palsy had been complete or partial post-operatively. That is to say, if recovery started out after the third month following surgery, the affected hemiface would never retrieve its normal or subnormal function (grade I and II as per J.W. House and D.E. Brackmann). In this series, facial function was restored in 45%, 15%, 21%, 11%, 1%, and 0 cases corresponding to grade I, II, III, IV, V and VI, respectively. Five grade III and IV nerve sections were repaired via five hypoglossofacial anastomosis operations. We propose a slight modification be brought to the House-Brackmann classification. The aim of this study was to accurately assess the complications and sequelae secondary to surgical ablation of unilateral acoustic neurinoma by an otoneurosurgical team utilizing almost exclusively the broadened translabyrinthic (B.TL) and medial cerebral fossa or supra-petrous (SP) approaches Despite achievements realized since W.F. House [23] described those, the main problem encountered has been-excluding major complications which are fortunately rare, remains the preservation of normal or subnormal facial function.

Adult↗
PubMed1990

[The retrolabyrinthine approach. Its value in the treatment of lesions of the lateral sinus].

The Authors conceive the petrous bone as made of four segments bounded by two vertical plans, one passing through the anterior wall of the internal auditory canal and the posterior wall of the external auditory canal, the other passing through the inner aspect of the tympanic cavity and the outer aspect of the labyrinthe. Drilling away one or several segments realizes a trans-petrous approach which always begins by drilling away the posterior-external segment, the retro-labyrinthine segment. Drilling away only the retro-labyrinthine segment realizes retro-labyrinthine approach which entirely put into sight the circumference of the bending of the lateral sinus. Thus, it is possible to perfectly and more easily deal with lesions localized in this region. The skin incision is made two fingerbreadths above and behind the external ear. The scalp uncovers the mastoid as far as the posterior ring of the external auditory canal. The superficial drilling uncovers the temporal dura, the lateral sinus and the occipital dura and between them the sinuso-dural angle. Then the mastoid is drilled away as far as the antrum is opened. Its aditus internally sided by the loop of the external semi-circular canal serves to localize the external surface of the labyrinthe. Finally, the retro-labyrinthine approach is bounded by the posterior wall of the external auditory canal anteriorly, by the external surface of the labyrinthe internally, by the dura of the superior surface of the petrous bone superiorly and by the bended part of the lateral sinus and the dura of the posterior surface of the petrous bone posteriorly. The closure is made with a dural graft then with bony dust mixed with biologic glue, then the petrectomy is plugged with under-skin fat and then the superficial planes are carefully stitched. The authors report 5 cases of meningiomas of the lateral sinus, 1 case of hemangiopericytoma and 2 dural arteriovenous fistulas which demonstrate the interest of this approach to lesions developed on this part of the lateral sinus.

Aged↗