RESUMO
INTRODUCTION: Multilevel cervical myelopathy without surgical treatment is generally poor in the neurological deficit without surgical decompression. The two main surgical strategies used for the treatment of multilevel cervical myelopathy are anterior decompression via anterior corpectomy or posterior decompression via laminctomy/laminoplasty. PRESENTATION OF CASE: We present the case of a 62 year-old lady, harboring rheumatoid artritis (RA) with gait disturbances, pain, and weakness in both arms. A C5 and C6 somatectomy, C4-C7 discectomy and, instrumentation and fusion with telescopic distractor "piston like", anterior plate and expandable screws were performed. Two days later the patient complained dysfagia, and a cervical X-ray showed hardware dislocation. So a C4 somatectomy, telescopic extension of the construct up to C3 with expandible screws was performed. After one week the patient complained again soft dysfagia. New cervical X-ray showed the pull out of the cranial screws (C3). So the third surgery "one stage combined" an anterior decompression with fusion along with posterior instrumentation, and fusion was performed. DISCUSSION: There is a considerable controversy over which surgical approach will receive the best clinical outcome for the minimum cost in the compressive cervical myelopathy. However, the most important factors in patient selection for a particular procedure are the clinical symptoms and the radiographic alignment of the spine. the goals of surgery for cervical multilevel stenosis include the restoration of height, alignment, and stability. CONCLUSION: We stress the importance of a careful patients selection, and invocated still the importance for 360° cervical fixation.
Assuntos
Vértebras Lombares/cirurgia , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Doenças da Coluna Vertebral/cirurgia , Fusão Vertebral/métodos , Humanos , Procedimentos Cirúrgicos Minimamente Invasivos/tendências , Radiografia , Doenças da Coluna Vertebral/diagnóstico por imagem , Fusão Vertebral/tendênciasRESUMO
INTRODUCTION: Laminoplasty has been proposed as a treatment for cervical stenotic myelopathy (CSM) as an alternative to standard laminectomy as this has been considered directly associated with an increased risk of postoperative deformity. METHODS: We retrospective reviewed postoperative results of open door laminoplasty (unilateral approach technique) compared with laminectomy in terms of clinical/electophysiological results (somatosensory evoked potentials - SSEP, and motor evoked potentials - MEP); in addition the rate of subsequent spinal deformities was analyzed in both techniques. RESULTS: Postoperative results in terms of late follow up neurological assessment and neurophysiological improvement was substantially comparable in both groups. Postoperative dynamic cervical X-rays showed a kyphotic deformity in (12.5%) in patients undergoing laminectomy; none was unstable. No case of kypothic deformity occurred in patients undergoing open door laminoplasty. Complication rate was similar in both groups. DISCUSSION AND CONCLUSIONS: Standard laminectomy seems to be associated to late cervical spine deformities in a more relevant percentage of patients, possibly leading to severe forms of kyphosis and segmental instability over time compared with open-door expansive laminoplasty. The unilateral approach represents an evolution to standard open door technique that further spares posterior elements, may decrease the incidence of progressive spinal deformity and prevent the need for subsequent spinal stabilization.
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Vértebras Cervicais/cirurgia , Laminectomia , Laminoplastia , Estenose Espinal/cirurgia , Adulto , Idoso , Vértebras Cervicais/diagnóstico por imagem , Feminino , Humanos , Cifose/diagnóstico por imagem , Cifose/etiologia , Laminectomia/efeitos adversos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/diagnóstico por imagem , Complicações Pós-Operatórias/etiologia , Radiografia , Estenose Espinal/diagnóstico por imagem , Resultado do TratamentoRESUMO
The purpose of this paper is to present the effectiveness of aerosol administration of TG in a group of oncological patients. Thiamphenicol is an antimicrobial agent active in the treatment of infection of different etiology and localisation due to its broad spectrum of antimicrobial activity as well as its pharmacokinetic properties. The data of the retrospective study analysis of the activity of TG, administered to oncological patients affected by infections of the respiratory tract, showed that TG administered alone or in association with other antibiotics was globally effective in more than 95% of patients. These positive results were obtained in immunologically compromised patients. The therapeutic advantages of using TG are: ease of use - aerosol therapy permits good local action; tolerability - no adverse reaction or intolerance; the possibility of using it in an ideal association with other antibiotics to combat the infectious pathology.
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Antibacterianos/administração & dosagem , Neoplasias de Cabeça e Pescoço/complicações , Infecções Respiratórias/tratamento farmacológico , Tianfenicol/análogos & derivados , Adulto , Aerossóis , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Tianfenicol/administração & dosagem , Tianfenicol/efeitos adversos , Tianfenicol/farmacologiaRESUMO
The meaning of nodal metastases in well-differentiated thyroid carcinoma is controversial. The Authors analyse the impact of lymphatic spread reviewing 1503 cases of well-differentiated thyroid carcinoma treated at the National Cancer Institute of Rome between 1988 and 2005, in order to detect significant prognostic factors through multivariate analysis. Overall, 462 cases of locally advanced well-differentiated thyroid carcinoma, were considered. A multivariate analysis of a subgroup, comprising 97 N+ consecutive cases of well-differentiated thyroid carcinoma, previously untreated, was performed to study prognostic factors for local (N+) and distant (M+) metastasis in well-differentiated thyroid carcinoma. Of the 97 cases, 88 were submitted to surgery for a large well-differentiated thyroid carcinoma, 9 for occult differentiated thyroid carcinoma. After surgery, 12 patients were lost to follow-up, 8 resulted pathologically negative, therefore only 77 cases of pN1 well-differentiated thyroid carcinoma were studied. Considering all cases of well-differentiated thyroid carcinoma, 10-year-overall survival was 58.7% for locally advanced well-differentiated thyroid carcinoma, compared to 94.8% in low stage cases. Neck dissection, margin infiltration and extra-capsular spread were significant prognostic factors. The Authors present a retrospective study of 77 patients with primary differentiated thyroid carcinoma, submitted to thyroidectomy and neck dissection aimed at analysing distribution of nodal metastases according to Robbins' levels classification and defining their prognostic value. All N1b cases, retrospectively reviewed (n. 77), presented clinical and histological evidence of neck nodes metastases from differentiated thyroid carcinoma; histological reports indicated tumour localisation and topographical distribution of metastases; papillary carcinoma was the most common type (72 cases), followed by follicular carcinoma (5 cases). Surgical treatment always comprised total thyroidectomy and 6(th) level dissection. Overall 52 cases were submitted to monolateral neck dissection, 25 to bilateral neck dissection. Treatment of the lateral neck was postero-lateral neck dissection (n. 53), selective lateral neck dissection (n. 20), modified radical and radical (n. 29). Cervical level IV was the most frequently involved (52%), extra-capsular spread of metastases was identified in 22% of the cases. Statistically significant prognostic factors for distant metastases and recurrence on the neck were follicular carcinoma (p < 0.01) and extra-capsular spread (p < 0.001). Age, pT, sex, number of positive nodal metastases, T-extension and the number of nodal positive levels were not significant. In the Authors' experience, histological grade of differentiation, wide tumour excision and neck dissection, in cases of N1b well-differentiated thyroid carcinoma, without residual disease (R1, R2), in the central and lateral neck, are determinant prognostic factors. Extracapsular spread in particular, was found to be a highly predictive factor either of distant metastasis or regional recurrence.
Assuntos
Carcinoma Papilar/secundário , Neoplasias da Glândula Tireoide/patologia , Adenocarcinoma Folicular , Adolescente , Adulto , Idoso , Carcinoma Papilar/cirurgia , Feminino , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/epidemiologia , Prognóstico , Estudos Retrospectivos , Neoplasias da Glândula Tireoide/secundário , Neoplasias da Glândula Tireoide/cirurgia , Adulto JovemRESUMO
Further understanding of the mechanisms involved in cellular and intracellular delivery of transgene is needed to produce clinical applications of gene therapy. The compartmental and computational model designed in this work is integrated with data from previous experiments to quantitatively estimate rate constants of plasmid translocation across cellular barriers in transgene delivery in vitro. The experimental conditions between two cellular studies were held constant, varying only the cell type, to investigate how the rates differed between cell lines. Two rate constants were estimated per barrier for active transport and passive diffusion. Translocation rates of intact plasmid across the cytoplasmic and nuclear barriers varied between cell lines. CV1 cells were defined by slower rates (0.23 h(-1) cytoplasmic, 0.08 h(-1) nuclear) than those of the HeLa cells (1.87 h(-1) cytoplasmic, 0.45 h(-1) nuclear). The nuclear envelope was identified as a rate-limiting barrier by comparing the rate of intact plasmid translocation at each barrier. Slower intact plasmid translocation in CV1 cells was correlated with a reduced absolute capacity for transgene efficiency in comparison with HeLa cells. HeLa cells were three times more efficient than CV1 cells at producing green fluorescent protein per intact plasmid delivered to the nucleus. Mathematical modeling coordinated with experimental studies can provide detailed, quantitative understanding of nonviral gene therapy.
Assuntos
Simulação por Computador , Terapia Genética/métodos , Modelos Genéticos , Translocação Genética , Linhagem Celular , Expressão Gênica , Células HeLa , Humanos , Plasmídeos , TransgenesRESUMO
During strenuous exercise in sheep, lung lymph flow increases within seconds and rises to levels 7- to 10-fold over baseline. Concomitant with the flow increase, the lymph protein content rapidly decreases to levels consistent with severe capillary hypertension. This pattern of clearance of filtered fluid is quite different than is seen with the passive capillary hypertension that results from mechanical obstruction of the mitral valve. In passive capillary hypertension, the increase in lymph flow and reduction in lymph protein content develop over several hours. The purpose of this study was to discover if these observed differences in edema clearance are related to the hyperpnea that accompanies exercise. Sheep were instrumented for continuous measurement of pulmonary arterial, left atrial, and systemic pressures, cardiac output by ultrasound, lung lymph flow, and ventilation. First, hemodynamics, ventilatory, and lymph clearance variables were measured during moderate exercise at 2.8 mph on a treadmill. Second, on a separate occasion, sheep were induced to hyperventilate to the same minute ventilation as during exercise, using modest CO2 stimulation. Lymph flow and hemodynamics were unaffected by this hyperpnea. The third arm of the experiment was to raise pulmonary microvascular pressure at rest to the level seen with exercise by means of a balloon catheter placed in the mitral valve. Lymph flow rose and protein content decreased slowly and to a lower degree than seen with exercise despite a comparable microvascular pressure. Finally, left atrial hypertension and induced hyperpnea were combined in sheep at rest, and the resulting lymph flow and protein content were the same as seen with exercise at similar pressures and ventilation. We conclude that hyperpnea is a major mechanism of interstitial liquid clearance during exercise, and may be largely responsible for preventing pulmonary edema that might occur at the high microvascular pressures of strenuous exercise.
Assuntos
Hiperventilação/fisiopatologia , Pulmão/fisiologia , Linfa , Condicionamento Físico Animal/fisiologia , Animais , Hemodinâmica , OvinosRESUMO
OBJECT: A modified technique of open-door laminoplasty for cervical stenotic myelopathy (CSM) is described, and the role of evoked potential monitoring in selecting patients for surgery and evaluating results is discussed. METHODS: Between October 1992 and October 1996, 33 patients with CSM underwent open-door laminoplasty. After surgery, in 27 patients (81.8%) different levels of clinical improvement were demonstrated, and in five of them (15%) full recovery was observed. The Japanese Orthopaedic Association score increased from 5 to 12 (mean 9.8) preoperatively to 8 to 14 (mean 11.6) postoperatively. At 1-year follow up, the N13 cervical response was restored in nine (75%) of 12 patients with isolated presurgical abnormality and in 57.1% of those with combined abnormalities of both N13 and P14 response. Although significant clinical improvement was observed in 82% of the cases, in 24 of 33 patients motor evoked potential abnormalities persisted at least at one explored level. CONCLUSIONS: Of several laminoplasty techniques, the one described here offers some advantages: preservation of biomechanical function of posterior muscular-ligamentous complex, prevention of laminar collapse, smaller degrees in reduction of range of cervical motion, stabilization of the spine with no postoperative malalignment, and maintenance of decompressive effect that avoids recurrent stenosis. Neurophysiological studies sometimes clarified neurological disorders that were only suspected on the basis of history and/or clinical examination, leading to early diagnosis.
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Vértebras Cervicais/patologia , Vértebras Cervicais/cirurgia , Potencial Evocado Motor , Potenciais Somatossensoriais Evocados , Monitorização Fisiológica/métodos , Procedimentos Ortopédicos/métodos , Idoso , Placas Ósseas , Vértebras Cervicais/fisiopatologia , Constrição Patológica/diagnóstico , Constrição Patológica/fisiopatologia , Constrição Patológica/cirurgia , Eletromiografia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Síndrome , Titânio , Tomografia Computadorizada por Raios XRESUMO
OBJECTIVE: To reduce antiparkinsonian medication in parkinsonian patients with bilateral high frequency subthalamic nucleus (STN) stimulation. BACKGROUND: Parkinsonian syndromes are characterized by hyperactivity of the STN. Preliminary data indicate that functional inactivation of the STN may reduce the requirement for dopaminergic therapy in PD. METHODS: Bilateral quadripolar leads were implanted stereotactically in the STN of seven patients with advanced PD (mean age, 57.4 years; mean disease duration, 15.4 years). High-frequency stimulation was applied for 24 hours a day. Following implantation, antiparkinsonian medication was reduced to the minimum possible and stimulation was gradually increased. The patients were evaluated in the practically defined "off" and "on" conditions using the Unified Parkinson's Disease Rating Scale (UPDRS) and the Schwab & England scale. The average follow-up was 16.3+/-7.6 months. A battery of neuropsychological tests was applied before and 9 months after the implant. RESULTS: Parkinsonian features improved in all patients--the greatest change seen in rigidity, then tremor, followed by bradykinesia. Compared with the presurgical condition, off-drug UPDRS motor scores improved by 41.9% on the last visit (p = 0.0002), UPDRS activities of daily living (ADL) scores improved by 52.2% (p = 0.0002), and the Schwab & England scale score improved by 213% (p = 0.0002). The levodopa-equivalent daily dose was reduced by 65%. Night sleep improved in all patients due to increased mobility at night, and in five patients insomnia was resolved. All patients gained weight after surgery and their appetite increased. The mean weight gain at the last follow-up was 13% compared with before surgery. During the last visit, the stimulation amplitude was 2.9+/-0.5 V and the total energy delivered per patient averaged 2.7+/-1.4 W x10(-6). The results of patient self-assessment scales indicated a marked improvement in five patients and a moderate improvement in the other two. The neuropsychological data showed no changes. Side effects were mild and tolerable. In all cases, a tradeoff between the optimal voltage and the severity of side effects made it possible to control parkinsonian signs effectively. The most marked side effects directly related to STN stimulation consisted of ballistic or choreic dyskinesias of the neck and the limbs elicited by contralateral STN stimulation above a given threshold voltage, which varied depending on the individual. CONCLUSIONS: Parkinsonian signs can be controlled by bilateral high-frequency STN stimulation. The procedure is well tolerated. On-state dyskinesias were greatly reduced, probably due to the reduction of total antiparkinsonian medication. Bilateral high-frequency STN stimulation compensated for drug reduction and elicited dyskinesias, which differ from those observed following dopaminergic medication. ADL improved significantly, suggesting that some motor tasks performed during everyday chores, and that are not taken into account in the UPDRS motor score, also improved.
Assuntos
Antiparkinsonianos/uso terapêutico , Terapia por Estimulação Elétrica , Doença de Parkinson/terapia , Núcleos Talâmicos/fisiopatologia , Relação Dose-Resposta a Droga , Terapia por Estimulação Elétrica/efeitos adversos , Seguimentos , Humanos , Pessoa de Meia-Idade , Movimento , Doença de Parkinson/fisiopatologia , Índice de Gravidade de Doença , Sono , Fatores de Tempo , Aumento de PesoRESUMO
The management of early-stage squamous cell carcinoma (SCC) of the supraglottic larynx is still controversial. Supraglottic laryngectomy as well as irradiation alone is correlated with good oncological and functional results. In order to evaluate the results and prognostic factors influencing the successful using radiotherapy (RT), the authors performed a retrospective study of 100 consecutive T1-T2 N0 M0 cases of SCC of the supraglottic larynx, treated at a single institution between 1983 and 1992. RT was delivered with 60Co or 6 MeV photons through two lateral parallel opposed portals encompassing the primary laryngeal tumor and the upper and mid-neck nodes (Robbins' levels II, III and V). Supraclavicular nodes (level IV) were electively irradiated in 54 patients with T2 N0 tumors only, using an anterior field with midline block. Sixty-three patients received conventional fractionation (2 Gy/fraction, once-a-day, five times a week), while 37 patients were irradiated according to a twice-a-day fractionation regimen (1.5 Gy/fraction, twice a day with six-hour interval, five days a week). The median total tumor dose delivered was 67 Gy. A multivariate analysis showed that performance status, tumor grade and fractionation modality were the only statistically significant variables influencing disease-free survival. Acute and late radiation reactions were relatively low. This retrospective study confirms that conservative management of T1-T2 N0 supraglottic cancer using RT can achieve good cure rates with the possibility of larynx preservation for the majority of the patients. The decision between different conservative treatment modalities may be influenced by several factors correlated to the patient's conditions, tumor characteristics, but especially treatment modalities.
Assuntos
Carcinoma de Células Escamosas/radioterapia , Neoplasias Hipofaríngeas/radioterapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/diagnóstico , Intervalo Livre de Doença , Relação Dose-Resposta à Radiação , Feminino , Humanos , Neoplasias Hipofaríngeas/diagnóstico , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Estadiamento de Neoplasias , Radioterapia/efeitos adversos , Estudos RetrospectivosRESUMO
BACKGROUND AND OBJECTIVE: The extent of thermal injury during laser prostatectomy is dependent on the light distribution in laser-irradiated tissue. As tissue is irradiated, the optical properties change as a function of temperature due to an alteration of molecular and cellular structure. The purpose of the present study was to determine how the exposure of both fresh and previously frozen canine prostate tissue to elevated temperatures affects the optical properties. STUDY DESIGN/MATERIALS AND METHODS: Optical properties were measured by using a double integrating sphere spectrophotometer with an inverse adding-doubling algorithm. Measurements were made at two wavelengths (1,064 nm and 633 nm) on samples heated in a waterbath in 5 degree-10 degree increments for 10 min through a 50 degrees C temperature range. RESULTS: Upon coagulation, the absorption coefficient of fresh tissue decreased from the baseline measurement for both wavelengths (0.027 +/- 0.003 to 0.019 +/- 0.002 for lambda = 1,064 nm; 0.073 +/- 0.007 to 0.061 +/- 0.006 for lambda = 633 nm). However, the scattering coefficient increased sharply from the baseline measurement following coagulation (3.06 +/- 0.26 to 6.05 +/- 0.29 for lambda = 1,064 nm; 4.89 +/- 0.23 to 7.22 +/- 0.30 for lambda = 633 nm). Thermal coagulation occurred during exposure to temperatures between 60 degrees C and 70 degrees C. CONCLUSION: Data obtained in this study indicate that thermal coagulation of tissue alters the optical properties. The extent to which these changes occur was found to be dependent on wavelength and freshness of tissue. These results are significant because they suggest how thermally induced changes in the optical properties may limit the depth of light penetration in tissue thus compromising treatment.
Assuntos
Temperatura Alta/efeitos adversos , Óptica e Fotônica , Próstata/química , Próstata/lesões , Ondas de Rádio/efeitos adversos , Algoritmos , Análise de Variância , Animais , Anisotropia , Criopreservação , Técnicas de Cultura , Modelos Animais de Doenças , Cães , Relação Dose-Resposta à Radiação , Humanos , Escala de Gravidade do Ferimento , Fotocoagulação a Laser/efeitos adversos , Masculino , Próstata/efeitos da radiação , Sensibilidade e Especificidade , Especificidade da Espécie , EspectrofotometriaRESUMO
Reconstruction following excision of tumors of the orbital-maxillary region represents a challenge to the head and neck surgeons. Microvascular techniques have significantly improved the possibilities of an adequate three-dimensional repair. Among the different available options, the latissimus dorsi myocutaneous flap (LDMF) has been considered, as it seems to fulfill the requirements for a functional obliterations of the orbital-maxillary cavity and to restore the facial contour. Two cases of large orbital-maxillary defects repaired with a LDMF are reported; in one of them the intraoral palatal competence and lining were achieved through a temporalis muscle flap. Technical remarks are presented and discussed as well as the indications and possibilities for more sophisticated reconstructions, aimed at a better cosmetic outcome.
Assuntos
Neoplasias de Cabeça e Pescoço/cirurgia , Maxila/cirurgia , Órbita/cirurgia , Retalhos Cirúrgicos , Carcinoma Basocelular/cirurgia , Carcinoma de Células Escamosas/cirurgia , Neoplasias de Cabeça e Pescoço/reabilitação , Humanos , Músculo Esquelético/transplante , Transplante de PeleRESUMO
This is a report of clinical manifestation, physical findings, neurophysiological data, magnetic resonance imaging, and results after surgery in a 71-years-old man with cervical abscess. Magnetic resonance imaging after two weeks of empiric antibiotic therapy demonstrated the persistence of an anterior cervical epidural collection and signs of spondylodiscitis at the C5-C6 and C6-C7 levels. Surgery was performed by posterior endoscopy assisted key-hole approach at the C2-C3 level to drain the abscess and to decompress the spinal cord. Postoperative specific medical treatment was then administered. A successful outcome, at 24 months follow-up, was achieved by surgery with complete clinical recovery, resolution of the abscess and healing of the spondylodiscitis. After unsuccessful blind medical therapy the minimally invasive microsurgical technique allowed us to keep the surgical injury of the healthy tissue to a minimum while producing the maximum therapeutic effect.
Assuntos
Abscesso/cirurgia , Vértebras Cervicais/cirurgia , Endoscópios , Microcirurgia/instrumentação , Doenças da Coluna Vertebral/cirurgia , Abscesso/diagnóstico , Idoso , Vértebras Cervicais/patologia , Discite/diagnóstico , Discite/cirurgia , Espaço Epidural , Seguimentos , Humanos , Imageamento por Ressonância Magnética , Masculino , Doenças da Coluna Vertebral/diagnósticoRESUMO
A modification of the Talairach stereotactic system is described which is able to incorporate CT data and provides both co-ordinate calculations, directly from the CT console screen and by a fiducial reference system. The device maintains the original base plate, thus allowing its interfacing with all the accessories of the early apparatus and its direct use in the stereotactic operating room. The instrument has shown great reliability in the localisation of brain lesions and considerable flexibility in many stereotactic operations such as biopsy procedures, brachytherapy, radiosurgery and stereotactically assisted resections.
Assuntos
Técnicas Estereotáxicas/instrumentação , Tomografia Computadorizada por Raios X/instrumentação , Desenho de Equipamento , HumanosRESUMO
OBJECTIVE: This study compares in vivo pulmonary blood flow patterns and shear stresses in patients with either the direct atrium-pulmonary artery connection or the bicaval tunnel connection of the Fontan procedure to those in normal volunteers. Comparisons were made with the use of three-dimensional phase contrast magnetic resonance imaging. METHODS: Three-dimensional velocities, flows, and pulmonary artery cross-sectional areas were measured in both pulmonary arteries of each subject. Axial, circumferential, and radial shear stresses were calculated with the use of velocities and estimates of viscosity. RESULTS: The axial velocities were not significantly different between subject groups. However, the flows and cross-sectional areas were higher in the normal group than in the two patient groups in both pulmonary arteries. The group with the bicaval connection had circular swirling in the cross section of both pulmonary arteries, causing higher shear stresses than in the controls. The disorder caused by the connection of the atrium to the pulmonary artery caused an increase in some shear stresses over the controls, but not higher than those found in the group having a bicaval tunnel. CONCLUSIONS: We found that pulmonary flow was equally reduced compared with normal flow in both patient groups. This reduction in flow can be attributed in part to the reduced size of the pulmonary arteries in both patient groups without change in axial velocity. We also found higher shear stress acting on the wall of the vessels in the patients having a bicaval tunnel, which may alter endothelial function and affect the longevity of the repair.
Assuntos
Técnica de Fontan , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Artéria Pulmonar/fisiopatologia , Veias Cavas/cirurgia , Adolescente , Adulto , Anastomose Cirúrgica , Velocidade do Fluxo Sanguíneo , Criança , Pré-Escolar , Feminino , Átrios do Coração/patologia , Átrios do Coração/fisiopatologia , Humanos , Masculino , Artéria Pulmonar/patologia , Atresia Pulmonar/diagnóstico , Atresia Pulmonar/cirurgia , Estresse Fisiológico/fisiopatologia , Sístole , Valva Tricúspide/anormalidades , Valva Tricúspide/cirurgiaRESUMO
In this study, an application was developed to measure three-dimensional blood flow in the main, right, and left pulmonary arteries of seven healthy volunteers using phase contrast magnetic resonance imaging (MRI). Presently, no other noninvasive technique is capable of providing this information. Flow, mean velocity, kinetic energy, and cross-sectional area were measured at multiple phases of the cardiac cycle and were consistent with previously reported values measured with one-dimensional velocity encoded MRI and Doppler echocardiography. Additionally, axial, circumferential, and radial shear stresses near the wall of the vessel at multiple phases of the cardiac cycle were estimated using the in-plane velocities. All three shear stresses were relatively constant along the vessel wall and throughout the cardiac cycle (approximately 7 dyn/cm2). This three-dimensional characterization of normal pulmonary blood flow provides a base line to which effects of altered pulmonary artery flow patterns in disease can be compared. [Morgan, V. L., T. P. Graham, Jr., and C. H. Lorenz. Circulation Suppl. 94:I-417 (abstract), 1996].
Assuntos
Angiografia por Ressonância Magnética/métodos , Artéria Pulmonar/fisiologia , Adolescente , Adulto , Fenômenos Biomecânicos , Engenharia Biomédica , Velocidade do Fluxo Sanguíneo/fisiologia , Feminino , Humanos , Masculino , Modelos CardiovascularesRESUMO
A three-dimensional magnetic resonance imaging (MRI) method to measure pulmonary edema and lung microvascular barrier permeability was developed and compared with conventional methods in nine mongrel dogs. MRIs were obtained covering the entire lungs. Injury was induced by injection of oleic acid (0.021-0.048 ml/kg) into a jugular catheter. Imaging followed for 0.75-2 h. Extravascular lung water and permeability-related parameters were measured from multiple-indicator dilution curves. Edema was measured as magnetic resonance signal-to-noise ratio (SNR). Postinjury wet-to-dry lung weight ratio was 5.30 +/- 0.38 (n = 9). Extravascular lung water increased from 2.03 +/- 1.11 to 3.00 +/- 1.45 ml/g (n = 9, P < 0.01). Indicator dilution studies yielded parameters characterizing capillary exchange of urea and butanediol: the product of the square root of equivalent diffusivity of escape from the capillary and capillary surface area (D1/2S) and the capillary permeability-surface area product (PS). The ratio of D1/2S for urea to D1/2S for butanediol increased from 0.583 +/- 0.027 to 0.852 +/- 0.154 (n = 9, P < 0.05). Whole lung SNR at baseline, before injury, correlated with D1/2S and PS ratios (both P < 0.02). By using rate of SNR change, the mismatch of transcapillary filtration flow and lymph clearance was estimated to be 0.2-1.8 ml/min. The filtration coefficient was estimated from these values. Results indicate that pulmonary edema formation during oleic acid injury can be imaged regionally and quantified globally, and the results suggest possible regional quantification by using three-dimensional MRI.
Assuntos
Edema Pulmonar/patologia , Algoritmos , Animais , Água Corporal/fisiologia , Permeabilidade Capilar/fisiologia , Cães , Pulmão/patologia , Imageamento por Ressonância Magnética , Microesferas , Ácido Oleico , Edema Pulmonar/induzido quimicamente , Síndrome do Desconforto Respiratório/induzido quimicamente , Síndrome do Desconforto Respiratório/patologiaRESUMO
In this study, lung filtration coefficient (Kfc) was measured in eight isolated canine lung preparations by using three methods: standard gravimetric (Std), blood-corrected gravimetric (BC), and optical. The lungs were held in zone III conditions and were subjected to an average venous pressure increase of 8.79 +/- 0.93 (mean +/- SD) cmH2O. The permeability of the lungs was increased with an infusion of alloxan (75 mg/kg). The resulting Kfc values (in milliliters . min-1 . cmH2O-1 . 100 g dry lung weight-1) measured by using Std and BC gravimetric techniques before vs. after alloxan infusion were statistically different: Std, 0.527 +/- 0.290 vs. 1. 966 +/- 0.283; BC, 0.313 +/- 0.290 vs. 1.384 +/- 0.290. However, the optical technique did not show any statistical difference between pre- and postinjury with alloxan, 0.280 +/- 0.305 vs. 0.483 +/- 0. 297, respectively. The alloxan injury, quantified by using multiple-indicator techniques, showed an increase in permeability and a corresponding decrease in reflection coefficient for albumin (sigmaf). Because the optical method measures the product of Kfc and sigmaf, this study shows that albumin should not be used as an intravascular optical filtration marker when permeability is elevated. However, the optical technique, along with another means of measuring Kfc (such as BC), can be used to calculate the sigmaf of a tracer (in this study, sigmaf of 0.894 at baseline and 0.348 after injury). Another important finding of this study was that the ratio of baseline-to-injury Kfc values was not statistically different for Std and BC techniques, indicating that the percent contribution of slow blood-volume increases does not change because of injury.
Assuntos
Aloxano/farmacologia , Pulmão/fisiologia , Testes de Função Respiratória/métodos , Animais , Pressão Sanguínea/efeitos dos fármacos , Pressão Sanguínea/fisiologia , Barreira Alveolocapilar/efeitos dos fármacos , Barreira Alveolocapilar/fisiologia , Corantes , Cães , Azul Evans , Técnicas In Vitro , Técnicas de Diluição do Indicador , Pulmão/efeitos dos fármacos , Modelos Biológicos , Permeabilidade/efeitos dos fármacos , Testes de Função Respiratória/instrumentaçãoRESUMO
A relatively recent method for reconstruction of the oral cavity after tumor removal employs the use of revascularized free flaps. In particular, the Radial Forearm Flap has gained significant international recognition. After a review of the history of this procedure, the authors describe the essential aspects of the technique including what is involved in removal as well as in microanastomosis and reconstruction. In addition, the paper also deals with operative patient monitoring, prevention and treatment of any complications. Finally, a series of 10 cases is presented all of which underwent surgery at the E.N.T. Division of the Varese Hospital. The case study presents the oncological and functional results and emphasizes the technical details of the entire sampling. The purpose of this work has been to demonstrate that this procedure can be used by an E.N.T. surgical staff without requiring input from an outside team of specialists. Although this technique is difficult and somewhat limited, it must be considered one of the most innovative proposals in the field of plastic, reconstructive surgery of the head and neck.