Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 35
Filtrar
1.
Laryngorhinootologie ; 81(8): 568-72, 2002 Aug.
Artigo em Alemão | MEDLINE | ID: mdl-12189573

RESUMO

A rare case of adenosquamous carcinoma in a 74 year-old man is reported. Presenting as a nodule on the soft palate, diagnosis was prolonged because of the benign macroscopic aspect. CT-scan and MR-tomography showed an encapsulated lesion but biopsy and histologic examination revealed the typical features of adenosquamous carcinoma. The tumour consisted of adenocarcinoma and squamous cell carcinoma in close proximity to minor salivary glands of which the tumour seemed to have its origin. This entity, although rare in the head and neck region has been documented to be very aggressive with early regional and hematogenic metastasis. Therefore it has to be distinguished from other tumours, especially from mucoepidermoid carcinomas of the salivary glands, which have a better prognosis. Adenosquamous carcinoma is considered to have poor radiosensitivity and chemotherapeutic approaches have also not been successful in the literature. In our case radical surgical therapy was performed by excision of the whole soft palate and bilateral neck dissection. This resulted in total removal of the tumour but revealed bilateral lymph node metastases. Vital functions were saved by reconstruction of the palate with a free vascularized tensor-fasciae-latae-perforator-flap. For the first time in a case of adenosquamous carcinoma carcinoembryonic antigen in serum was monitored. A pretherapeutical 29-fold elevation resulted in a marked decrease after surgery, but supranormal values indicated remaining tumour burden which was found in metastases in the lung. Because of the limitations in therapy, early histologic diagnosis is most important in this highly malignant tumour.


Assuntos
Carcinoma Adenoescamoso , Neoplasias Palatinas , Idoso , Biópsia , Antígeno Carcinoembrionário/análise , Carcinoma Adenoescamoso/diagnóstico , Carcinoma Adenoescamoso/diagnóstico por imagem , Carcinoma Adenoescamoso/patologia , Carcinoma Adenoescamoso/cirurgia , Diagnóstico Diferencial , Seguimentos , Humanos , Neoplasias Pulmonares/secundário , Metástase Linfática , Imageamento por Ressonância Magnética , Masculino , Neoplasias Palatinas/diagnóstico , Neoplasias Palatinas/diagnóstico por imagem , Neoplasias Palatinas/patologia , Neoplasias Palatinas/cirurgia , Palato Mole/patologia , Prognóstico , Retalhos Cirúrgicos , Fatores de Tempo , Tomografia Computadorizada por Raios X , Resultado do Tratamento
2.
Wien Klin Wochenschr ; 112(17): 767-71, 2000 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-11042906

RESUMO

This prospective open study was performed to examine the relation between pathologic findings of the upper respiratory tract and the types of noncentral sleep disorders (rhonchopathy, obstructive sleep apnea). 312 men and 274 women aged between 35-75 years attended our outpatient department for relief of their nocturnal breathing disorder. About 1/3 of the patients suffered only of habitual rhonchopathy and 2/3 were obstructive. No findings of the head and neck examination could predict the degree of oxygen desaturation, although pathologies of the nose (73.68%), the soft palate (94.1%) and narrowing of the oro- and hypopharynx (74.19%) were very common in patients with sleep disorder. At least one pathology could be found in every patients. The more pathologies were found the higher was the risk of obstructive sleep apnoea with desaturation below 70%. Unrelated tonsillectomy (51.36%) did not prevent nocturnal breathing disorders.


Assuntos
Síndromes da Apneia do Sono/diagnóstico , Ronco/diagnóstico , Adulto , Idoso , Resistência das Vias Respiratórias , Índice de Massa Corporal , Interpretação Estatística de Dados , Feminino , Hemodinâmica , Humanos , Hipofaringe/fisiopatologia , Masculino , Manometria , Pessoa de Meia-Idade , Nariz/fisiopatologia , Orofaringe/fisiopatologia , Oximetria , Oxigênio/sangue , Palato/fisiopatologia , Estudos Prospectivos , Ventilação Pulmonar , Síndromes da Apneia do Sono/fisiopatologia , Ronco/fisiopatologia
3.
Wien Klin Wochenschr ; 112(14): 617-23, 2000 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-11008323

RESUMO

PURPOSE: Glutathione has been shown to be an effective chemoprotector against cisplatin-induced side effects in patients with ovarian cancer. In view of this fact, we performed a randomized clinical pilot-trial in the management of other solid tumors in order to compare application of Glutathione to intensive hydration in patients undergoing chemotherapy with a regimen including cisplatin. PATIENTS AND METHODS: Twenty patients suffering from advanced non small cell lung cancer (n = 6) or head- and neck cancer (n = 14) were enrolled in the study. All patients received 80 mg/m2 cisplatin along with etoposide or 5-fluorouracil every 4 weeks. Patients randomized to application of Glutathione (n = 11) received 5 g of Glutathione immediately before application of cisplatin followed by 2000 ml of normal saline. Patients in the control group (n = 9) received 2000 ml electrolyte infusion before and 2000 ml of normal saline with forced diuresis after cisplatin. RESULTS: The intensity of hematologic toxicity was significantly less pronounced in patients treated with Glutathione than in the control group (hemoglobin: 10.7 vs 9.5 mg% respectively, p = 0.039; white blood cell count 3.3 vs 2.2 x 103/microliter respectively, p = 0.004; platelets 167 vs 95 x 103/microliter respectively, p = 0.02), whereas in terms of non-hematologic toxicity no difference was observed. Objective remission occurred in 6 out of 11 evaluable patients from the group receiving Glutathione (55%; complete remission: 9%; partial remission: 46%), and in 4 out of 8 evaluable patients from the control group (partial remission: 50%). However, there was no statistical difference in terms of response and overall survival (13.5 months vs. 10.5 months) between the two groups. CONCLUSIONS: Application of Cisplatin and Glutathione seems to be safe and feasible and the antitumoral efficacy of cisplatin is apparently not impaired by the concomitant use of Glutathione in patients with solid tumors.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Antioxidantes/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Cisplatino/efeitos adversos , Glutationa/uso terapêutico , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Antioxidantes/administração & dosagem , Cisplatino/administração & dosagem , Feminino , Fluoruracila/administração & dosagem , Fluoruracila/efeitos adversos , Glutationa/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Estudos Prospectivos , Análise de Sobrevida , Resultado do Tratamento
4.
Ann Intern Med ; 128(9): 705-12, 1998 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-9556463

RESUMO

BACKGROUND: Accumulating evidence suggests that postmenopausal hormone use may decrease the risk for colorectal cancer. OBJECTIVE: To examine the relation of postmenopausal hormone therapy to colorectal adenoma and cancer. DESIGN: Prospective cohort and nested case-control studies. SETTING: Nurses' Health Study, a study of registered nurses recruited from 11 U.S. states. PARTICIPANTS: 59 002 postmenopausal participants in the Nurses' Health Study. MEASUREMENTS: Self-reported data on hormone use and cases of distal colorectal adenoma and colorectal cancer obtained from biennial questionnaires completed from 1980 to 1994. Cases of colorectal adenoma and cancer were confirmed by medical record review. RESULTS: 470 women developed colorectal cancer, and 838 developed distal colorectal adenomas. Current use of postmenopausal hormones was associated with a decreased risk for colorectal cancer (relative risk [RR], 0.65 [95% CI, 0.50 to 0.83]). This association was attenuated in past users (RR, 0.84 [CI, 0.67 to 1.05]) and disappeared 5 years after hormone use was discontinued (RR, 0.92 [CI, 0.70 to 1.21]). Longer duration of current use did not afford greater protection (RR with > or =5 years of use, 0.72 [CI, 0.53 to 0.96]). Even after exclusion of women who reported having screening sigmoidoscopy, the relative risk for colorectal cancer seen with current hormone use was 0.64 (CI, 0.49 to 0.82). This suggests that the apparent protection is unlikely to be due to more intensive screening among hormone users. Current users also had a lower risk for large (> or =1 cm) adenomas than did women who had never used hormones (RR, 0.74 [CI, 0.55 to 0.99]), although no overall material association was seen between colorectal adenoma and current hormone use (RR, 0.91 [CI,0.77 to 1.08]). CONCLUSIONS: The risk for colorectal cancer was decreased among women currently receiving postmenopausal hormone therapy, but the apparent reduction substantially diminished upon cessation of therapy. Hormone use was inversely associated with large colorectal adenomas but not small ones.


Assuntos
Adenoma/epidemiologia , Neoplasias Colorretais/epidemiologia , Terapia de Reposição de Estrogênios , Estrogênios/administração & dosagem , Pós-Menopausa , Adulto , Índice de Massa Corporal , Estudos de Casos e Controles , Feminino , Seguimentos , Humanos , Incidência , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Sigmoidoscopia , Inquéritos e Questionários , Fatores de Tempo , Estados Unidos/epidemiologia
5.
Int J Oral Maxillofac Surg ; 27(5): 352-5, 1998 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9804197

RESUMO

In a prospective study, a new biodegradable osteosynthesis material for the facial skeleton has been used in 27 patients with zygomatic fractures. In the six-month follow-up period, the first ten patients showed clinically and radiologically uneventful healing of bone. There were no implant-related complications. The main advantages of the new material are its malleability when heated, enabling fast adaptation to the bone surface, and the avoidance of a second operation for implant removal.


Assuntos
Implantes Absorvíveis , Placas Ósseas , Fixação Interna de Fraturas/instrumentação , Fraturas Zigomáticas/cirurgia , Adolescente , Adulto , Idoso , Materiais Biocompatíveis , Criança , Feminino , Seguimentos , Consolidação da Fratura , Humanos , Ácido Láctico , Masculino , Pessoa de Meia-Idade , Ácido Poliglicólico , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Polímeros , Resultado do Tratamento
6.
Audiology ; 37(1): 38-51, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9474438

RESUMO

Although health problems in musicians have been previously reported; not much is known about noise-induced hearing loss due to choir singing. However, there are data to show that peak levels of more than 110 dB SPL are produced in choir singing, and major parts of sound energy can be found below 1 kHz and even 500 Hz but not below 100 Hz. To find out about possible hearing loss due to professional choir singing, we measured the hearing threshold level of 62 choir singers in a large opera choir. Most publications about noise-induced hearing loss report that the high-frequency region is impaired most. However, in our study the low frequency region was affected most, when compared with normative data (especially ISO 7029). Control groups of women and men with normal auditory function did not show pure-tone hearing thresholds different from ISO 7029. The permanent threshold shifts at 250 Hz and above are most likely noise induced with choir singing as noise source. However, hearing losses at 125 Hz and possibly partial at 250 Hz are caused by some other effect. An (unproven) hypothesis is that singing might lead to increased endolymph pressure, and thus might cause hearing loss especially in the low-frequency region. Whether more choirs show similar hearing impairment and whether singing raises cerebrospinal fluid pressure will be the subject of further investigations.


Assuntos
Perda Auditiva Provocada por Ruído/etiologia , Música , Adulto , Audiometria de Tons Puros , Limiar Auditivo , Feminino , Perda Auditiva Provocada por Ruído/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Fatores Sexuais
7.
Eur Arch Otorhinolaryngol ; 254(9-10): 470-3, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9438121

RESUMO

Non-Hodgkins' lymphomas are relatively common tumors in the head and neck and should always be considered in the differential diagnosis of any mass lesion in this region, especially in cases with single enlarged lymphnodes of unknown origin and symptoms that can only be explained by metastasis. The diagnosis is usually established by multidisciplinary collaboration. We report our experience in managing a 48-year-old man who was found to have a non-Hodgkins' lymphoma in his neck that was complicated by a metastasis to his brain causing incomplete ophthalmoplegia, a rare primary complication. The differential diagnosis and the examinations leading to the diagnosis are discussed.


Assuntos
Linfoma de Burkitt/diagnóstico , Neoplasias de Cabeça e Pescoço/diagnóstico , Oftalmoplegia/etiologia , Neoplasias Encefálicas/complicações , Neoplasias Encefálicas/secundário , Linfoma de Burkitt/patologia , Neoplasias de Cabeça e Pescoço/complicações , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade
8.
Lasers Surg Med ; 20(3): 265-71, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9138255

RESUMO

BACKGROUND AND OBJECTIVE: The specifics of the ablation mechanism of the holmium:YAG laser remain largely unexplored. Following laser exposure to the oral mucosa of rats, the ultrastructural damage profile obtaining to varying degrees in blood vessels, erythrocytes, nerves, and muscle cells was examined. An attempt was made to relate the cytoplasmatic alterations to the tissue ablation modes of midinfrared lasers described in the literature. STUDY DESIGN/MATERIALS AND METHODS: The biological effects of a new pulsed holmium:YAG laser (lambda = 2,120 nm) on the oral mucosa of rats were examined by light and transmission electron microscopy. Laser incisions reaching into the muscle layer were made on different sites of the tongue of white rats. Laser energy (400 mJ, 2.5 microseconds pulse, 2 Hz) was delivered to the target via 400 microns nylon fibers. RESULTS: The fine-structural morphology of the sublingual mucosa after laser surgery of the epithelial surface revealed no carbonization layer but a 150-micron-wide zone of lacunar structures extending to the lamina propria. In the muscle cells there is partial decomposition of the cell contents resulting in the development of electron optically empty spaces within the cortical cytoplasm underneath the intact plasma membrane of the muscle cell. The organelles within the cell remain ultrastructurally intact. CONCLUSION: These features support the assumption of an additional nonthermal holmium:YAG laser-tissue interaction.


Assuntos
Terapia a Laser , Mucosa Bucal/ultraestrutura , Animais , Masculino , Mucosa Bucal/cirurgia , Ratos
9.
Laryngorhinootologie ; 75(11): 691-6, 1996 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-9063839

RESUMO

BACKGROUND: Distinguishing schwannoma from neurofibroma of the paranasal sinuses can be difficult. PATIENTS: We present the rare case of malignant peripheral nerve sheath tumor of the frontoethmoid complex that occurred in a patient who had suffered from schwannoma at the same site 7 years before. The tumor was examined clinically, histologically, and immunohistochemically. RESULTS: Although complete surgical excision of the primary tumor should have been an apparently adequate management for benign schwannoma, the tumor recurred and even metastasized into the brain. The tumor was resistant to aggressive surgical therapy combined with adjuvant irradiation and gamma knife therapy. The results of histological examinations identified schwannian features of the primary tumor and clearly outlined differentiation to solitary neurofibroma. CONCLUSIONS: Considering that schwannomas can be predominantly benign with foci of malignant areas and that there are reported cases of malignant transformation of benign schwannomas, the present consensus in management of small and low-grade malignant schwannomas is complete surgical excision with negative margins. The therapy of choice for high-grade malignant schwannomas is aggressive surgical resection, with wide tumor free margins, combined with adjuvant irradiation and chemotherapy.


Assuntos
Transformação Celular Neoplásica/patologia , Seio Etmoidal/patologia , Seio Frontal/patologia , Recidiva Local de Neoplasia/patologia , Neurilemoma/patologia , Neoplasias dos Seios Paranasais/patologia , Idoso , Biomarcadores Tumorais/análise , Terapia Combinada , Seguimentos , Humanos , Técnicas Imunoenzimáticas , Masculino , Recidiva Local de Neoplasia/terapia , Neurilemoma/terapia , Neoplasias dos Seios Paranasais/terapia , Fosfopiruvato Hidratase/análise , Proteínas S100/análise , Vimentina/análise
10.
Br J Cancer Suppl ; 27: S279-81, 1996 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8763897

RESUMO

From October 1990 to March 1994, 90 patients entered a prospectively randomised trial in head and neck cancer. All patients had verified squamous cell carcinoma and were referred for primary radiation therapy. Tumours originated in the oral cavity in 25, oropharynx in 37, larynx in 15 and hypopharynx in 13 cases. Patients' stages were predominantely T3 and T4 (71/90) and had lymph node metastases (60/90). Seventy-nine male patients and 11 female patients, with a median age of 57 years (range 37-76 years) were treated. Patients were randomised to one of three treatment options: conventional fractionation (CF) consisting of 70 Gy in 35 fractions over 7 weeks or continuous hyperfractionated accelerated radiation therapy (Vienna-CHART) or Vienna-CHART with administration of a single dose of mitomycin C on day 5 of treatment (V-CHART + MMC). By the accelerated regimen a total dose of 55.3 Gy was given in 33 fractions within 17 consecutive days. Acute mucositis was the main toxicity recorded in those patients treated by accelerated fractionation, although the overall duration of mucosal reaction did not differ in the three treatment groups. There was no influence on local toxicity if MMC was added to radiation therapy or not. Those patients treated with additional MMC experienced a grade III/IV haematological toxicity in 4/28 cases. Complete remission (CR) was recorded in 48% following CF, 79% after Vienna-CHART (P < 0.05) and 71% after Vienna-CHART + MMC. The overall local failure rates were 73%, 59% and 42% (P = NS) for patients treated by CF, Vienna-CHART and Vienna-CHART + MMC respectively.


Assuntos
Carcinoma de Células Escamosas/radioterapia , Neoplasias de Cabeça e Pescoço/radioterapia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mitomicina/efeitos adversos , Mitomicina/uso terapêutico , Estudos Prospectivos , Dosagem Radioterapêutica
11.
J Oral Maxillofac Surg ; 54(2): 156-61, 1996 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8604062

RESUMO

PURPOSE: This study evaluated whether the Augustine Guide, a device enabling blind oral intubation, carries a high risk for laryngopharyngeal trauma in routine airway management. PATIENTS AND METHODS: Telescopic laryngoscopic or microlaryngoscopic examinations were performed in 20 patients before and immediately after blind oral intubation, as well as 24 hours postoperatively. RESULTS: Intubation using the Augustine Guide was successful in all but one patient. However, 18 of 20 patients showed evidence of considerable trauma to the laryngopharyngeal region. Vallecular edema, epiglottic swelling, mucosal lacerations, and vocal cord hematomas, causing a high percentage of postoperative discomfort, occurred in a very uniform pattern. CONCLUSIONS: It was concluded that blind oral intubation using the Augustine Guide should not be used in routine airway management but should only be used in special indications.


Assuntos
Intubação Intratraqueal/efeitos adversos , Laringe/lesões , Faringe/lesões , Adulto , Feminino , Humanos , Intubação Intratraqueal/instrumentação , Intubação Intratraqueal/métodos , Intubação Intratraqueal/estatística & dados numéricos , Laringoscopia , Masculino , Pessoa de Meia-Idade , Período Pós-Operatório
12.
Lasers Surg Med ; 18(3): 271-7, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8778523

RESUMO

BACKGROUND AND OBJECTIVE: The use of conventional drilling procedures in cochlear implant surgery of ossified cochleae poses special risks to the facial nerve and the carotid artery. This study evaluated the alternate use of flexible fiberoptic endoscopy and mid-infrared laser surgery for recanalization of partially and artificially obliterated cochleae in freshly dissected human cadavers. STUDY DESIGN/MATERIALS AND METHODS: A pulsed Holmium:YAG-laser (lambda = 2120 nm) was used in the free-running mode (1180 mJ, 250 microseconds pulse, 5 Hz). A 660 microns optic quartz fiber was positioned in the center of the round window niche and slowly--endoscopically guided--advanced in contact shooting over 1.5 cm, creating by vaporization and photoablation a passage through the artificial bony occlusion in the basal segment of the cochlea. RESULTS: In all experiments, laser application (110-130 pulses) resulted in complete recanalization of the bony occlusions without damaging surrounding structures. The microendoscopy proved capable of guiding the laser fiber through the curved segment of the basal turn allowing identification of normal bone, bone cement, and laser-treated bone cement. CONCLUSION: If partial ossification of the basal turn is present, this technique could give access to place analog as well as digital implants deep within the cochlea.


Assuntos
Cóclea/cirurgia , Implantes Cocleares , Endoscópios , Terapia a Laser/instrumentação , Osso Petroso/cirurgia , Cóclea/patologia , Humanos , Microcirurgia/instrumentação , Osso Petroso/patologia
13.
Obstet Gynecol Surv ; 50(10): 739-46, 1995 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8524524

RESUMO

Vulvar melanoma is an unusual tumor with a poor prognosis. Most surgeons have abandoned radical vulvectomy as the treatment of choice. The role of elective node dissection is controversial. Currently effective adjuvant therapy is lacking. In this paper 51 sources concerning melanoma and/or melanoma of the vulva were reviewed, 43 of these sources were considered to be pertinent and current enough to include in this review. The objective was to describe current knowledge about the natural history, staging, pathology, and treatment of melanoma of the vulva. It has been found that melanoma continues to be difficult to treat when in advanced stages. Microstaging systems offer clinicians the best prognostic information. In many patients, less radical surgical treatment offers equal cure rates with decreased morbidity.


Assuntos
Melanoma , Neoplasias Vulvares , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Excisão de Linfonodo , Melanoma/epidemiologia , Melanoma/patologia , Melanoma/cirurgia , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Taxa de Sobrevida , Resultado do Tratamento , Neoplasias Vulvares/epidemiologia , Neoplasias Vulvares/patologia , Neoplasias Vulvares/cirurgia
14.
HNO ; 43(6): 389-92, 1995 Jun.
Artigo em Alemão | MEDLINE | ID: mdl-7642401

RESUMO

Hemangiomas of the upper aerodigestive tract may present a therapeutic challenge depending on their size, location and symptoms. We present a rare case of cavernous hemangioma of the aryepiglottic fold applaning in an adult. First symptoms were dysphagia and hoarseness. Surgical removal was performed with a CO2/Nd: YAG combination laser under microscopic control. After a regular postoperative course the patient has remained disease-free after a 2 year follow up period. We suggest the use of the CO2/Nd: YAG combination laser as preferred treatment in cases of exophytic hemangiomas, because of the favorable combination of excision with photocoagulation effects.


Assuntos
Hemangioma Cavernoso/cirurgia , Neoplasias Hipofaríngeas/cirurgia , Terapia a Laser/instrumentação , Adulto , Feminino , Seguimentos , Hemangioma Cavernoso/diagnóstico , Humanos , Neoplasias Hipofaríngeas/diagnóstico , Hipofaringe/patologia , Hipofaringe/cirurgia , Imageamento por Ressonância Magnética
16.
Laryngorhinootologie ; 73(3): 136-42, 1994 Mar.
Artigo em Alemão | MEDLINE | ID: mdl-8172633

RESUMO

A pulsed holmium: YAG-laser (lambda = 2120 nm) was used to reopen the basal turn of artificially obliterated human cochleas in freshly dissected cadavers for intracochlear insertion of the stimulation electrode of a cochlear implant under simulated surgical conditions. Laser energy was transmitted through a 400 microns nylon fibre via the opened facial recess directly to the round window niche. At an energy level of 500 mJ/2.5 microseconds pulse, a repetition rate of 2 Hz, and an exposure time of 20-30 s, the photo-ablative mechanism of laser-bone interaction, which has only a limited thermal component, led to recanalisation of the basal turn of the cochlea in a length of 8-10 mm without damaging the surrounding structures. Light microscopic changes in the cochlea were evaluated following laser recanalisation. The artificial bony occlusion and the recanalised basal turn of the cochlea were visualised by means of computed tomography and histological thin section technique.


Assuntos
Implantes Cocleares , Labirintite/cirurgia , Terapia a Laser , Ossificação Heterotópica/cirurgia , Cóclea/patologia , Surdez/patologia , Surdez/cirurgia , Orelha Interna/patologia , Humanos , Labirintite/patologia , Ossificação Heterotópica/patologia , Tomografia Computadorizada por Raios X
17.
Eur Arch Otorhinolaryngol ; 251(3): 165-9, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-8080636

RESUMO

A pulsed holmium:YAG laser (lambda = 2120 nm) was used to reopen the basal turn of artificially obliterated human cochleas in freshly dissected cadavers. This allowed intracochlear insertion of the stimulation electrode of a cochlear implant under simulated surgical conditions. Laser energy was transmitted through a 400-microns nylon fiber via the opened facial recess directly to the round window niche. At an energy level of 500 mJ per 2.5 microseconds pulse, a repetition rate of 2 Hz, and an exposure time of 20-30 s, the photo-ablative mechanism of laser-bone interaction led to a 8-10 mm recanalization of the basal turn of the cochlea without damaging surrounding structures. The artificial bony occlusion and the recanalized basal turn of the cochlea were visualized by means of computed tomography and studied under light microscopy, using a histologic thin-section technique.


Assuntos
Doenças Cocleares/cirurgia , Terapia a Laser , Osso Temporal/cirurgia , Silicatos de Alumínio , Cimentos Ósseos , Cóclea/diagnóstico por imagem , Cóclea/patologia , Cóclea/cirurgia , Doenças Cocleares/diagnóstico por imagem , Doenças Cocleares/patologia , Implantes Cocleares , Eletrodos Implantados , Tecnologia de Fibra Óptica/instrumentação , Cimentos de Ionômeros de Vidro , Hólmio , Humanos , Terapia a Laser/instrumentação , Nylons , Osso Petroso/patologia , Janela da Cóclea/diagnóstico por imagem , Janela da Cóclea/patologia , Janela da Cóclea/cirurgia , Osso Temporal/diagnóstico por imagem , Osso Temporal/patologia , Tomografia Computadorizada por Raios X , Ítrio
18.
Wien Klin Wochenschr ; 106(2): 45-53, 1994.
Artigo em Alemão | MEDLINE | ID: mdl-8146995

RESUMO

Laser therapy in otolaryngology--head and neck surgery using laser types working in the range of the visible and infrared part of the electromagnetic spectrum is well established. The laser types usually employed for micro- and macrosurgery of the aero-digestive tract and for microsurgery of the middle ear, involving thermal ablation of tissue and extensive areas of damage are described, as well as recent advances in laser technology for future use. The mechanisms by which non-thermal, photo-ablative pulsed solid-state crystal infrared and UV-excimer lasers and photodynamic therapy affect biological tissues are reported. The advantageous main areas of application of the different types of laser according to their physical properties are compared on the basis of the results of our own studies and the relevant literature.


Assuntos
Terapia a Laser/instrumentação , Microcirurgia/instrumentação , Otorrinolaringopatias/cirurgia , Neoplasias Otorrinolaringológicas/cirurgia , Animais , Humanos , Otorrinolaringopatias/patologia , Neoplasias Otorrinolaringológicas/patologia , Cicatrização/fisiologia
19.
Eur J Anaesthesiol ; 10(6): 433-6, 1993 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11767319

RESUMO

Laser-induced ignition of the endotracheal tube is the most morbid event that may occur during laser surgery of the upper respiratory/digestive tract. The efficacy of two new laser-resistant endotracheal tubes, the Laser-Flex stainless steel tube by Mallinckrodt and the Laser-Shield II tube with teflon-aluminium-silicone coating by Xomed-Treace, was studied under exposure to a newly introduced pulsed infrared laser (holmium:YAG, lambda = 2120 nm) in an experimental setting. The time from the onset of exposure until tube perforation was recorded. Laser exposure was continued for up to 180 s unless tube ignition occurred. Temperature during the following 30 s laser application was measured close to the target zones. The irradiance level of the holmium:YAG laser was in the range required for photoablation and plasma formation and led to laser-induced tube ignition in both types of tube. The steel tube showed greater resistance to laser-induced wall damage than the teflon-aluminium silicone tube. The maximum temperature increase following laser exposure was moderate in both tubes; the mean rise of 10 degrees C for the Laser-Shield tube and 23 degrees C for the Mallinckrodt tube correlating with the physical effects of photoablation.


Assuntos
Hólmio , Intubação Intratraqueal/instrumentação , Lasers , Alumínio , Raios Infravermelhos , Intubação Intratraqueal/efeitos adversos , Plásticos , Politetrafluoretileno , Silicones , Aço , Temperatura
20.
Oral Surg Oral Med Oral Pathol ; 76(4): 425-32, 1993 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8233420

RESUMO

The in vivo tissue ablation characteristics of a pulsed infrared laser (Hol:YAG, lambda = 2120 nm) and a pulsed excimer laser (XeCl, lambda = 308 nm) were studied in an animal model. Laser energy was delivered via nylon fibers for the Hol:YAG laser and via quartz fibers for the excimer laser. Laser incisions were made under precise reproducible conditions on the sublingual side of the tongue and the gingiva of white rats. Laser surgery was done at two different energy output settings for the Hol:YAG laser and at one setting for the excimer laser. Histologic studies revealed tissue defects with clean contours for both laser types with small zones of necrosis of the adjacent tissue (Hol:YAG: 180 microns to 640 microns; excimer: 40 microns to 160 microns) and without carbonization. Both laser types function on the principal of photoablation and permit excellent control of tissue ablation. Wound healing was studied over a 10-day period and showed complete wound closure by re-epithelialization. The in vivo tissue ablation characteristics and the surgical reliability of the two lasers are compared and discussed with respect to oral and periodontal surgery.


Assuntos
Terapia a Laser/instrumentação , Lasers , Cirurgia Bucal/instrumentação , Animais , Gengiva/cirurgia , Masculino , Ratos , Língua/cirurgia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA