970 resultados para Portal Vein
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OBJETIVO: Apresentar e discutir indicações e resultados iniciais de duas alternativas técnicas para reconstrução portal em receptores de transplante hepático com veia porta trombosada ou hipoplásica. MÉTODO: São apresentados três casos de transplante hepático em portadores de veia porta imprestável para revascularização do enxerto. Constatada essa inadequação, por ausência de calibre e fluxo mínimos para uma anastomose segura com a veia porta do doador, a veia gástrica esquerda (duas vezes) ou a veia mesentérica inferior do receptor foi dissecada, ligada distalmente, transposta e anastomosada com a veia porta do doador. RESULTADOS: Nos três casos, as anastomoses resultaram isodiamétricas, sem torsões ou acotovelamentos, permitindo uma revascularização do enxerto homogênea, adequada do ponto de vista macroscópico e funcional, comprovada pela evolução favorável e por fluxometria Doppler pós-operatória. CONCLUSÕES: Os autores concluem que a veia gástrica esquerda e a veia mesentérica inferior podem se constituir em boas alternativas para a reconstrução portal de receptores de transplante hepático com veia porta inadequada.
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OBJETIVO: Desenvolver um modelo experimental de formação de varizes esofágicas por hipertensão portal esquistossomótica em hamsters. MÉTODO: Utilizamos 55 hamsters divididos em dois grupos: grupo I composto de 50 animais infectados com injeção percutânea de 100 cercarias de Schistosoma mansoni da cepa BH; e grupo II composto de cinco animais sadios (grupo de controle). Foram mantidos por um período de incubação de oito semanas. Após este período os animais eram pesados e posteriormente avaliados cirurgicamente quanto à pressão portal, e aspectos macroscópicos e microscópicos do baço, fígado e esôfago tóraco-abdominal. RESULTADOS: Todos os animais do grupo I perderam peso, enquanto os animais do grupo II apresentavam um aumento do peso corporal durante o período de incubação. Vinte e seis (52%) animais do grupo I morreram. Dos 24 hamsters que permaneceram compondo o grupo I observamos uma pressão portal significativamente elevada quando comparada aos animais do grupo II (8,33 x 4,60 cm H2O respectivamente). Verificamos a presença de varizes esofágicas em 16 hamsters do grupo I (66,70%) sendo nestes animais a pressão portal significativamente mais elevada quando comparada aos animais do grupo I que não desenvolveram varizes (9,50 x 6,00 cm H2O respectivamente). CONCLUSÃO: É possível desenvolver em hamsters um modelo experimental de hipertensão portal esquistossomótica aguda com formação de varizes esofágicas.
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OBJETIVO: Avaliar a morbidade e a mortalidade no tratamento cirúrgico da hipertensão portal esquistossomótica em pacientes portadores de inversão do diâmetro entre a veia porta e veia esplênica. MÉTODOS: Estudo transversal retrospectivo, de pacientes submetidos ao tratamento cirúrgico da hipertensão no período entre setembro de 1993 e Janeiro de 2004. A população do estudo foi distribuída em dois grupos: a) Inversão - calibre da veia esplênica maior ou igual ao da veia porta) e b) grupo controle (calibre da veia porta maior que o da veia esplênica). Na análise estatística foram utilizados o teste t de student para diferença de médias, quiquadrado para diferença de proporções e o exato de Fisher para amostras reduzidas. RESULTADOS: 169 pacientes foram analisados com seguimento pós-operatório médio de 23,6 meses. 21 pacientes (12,4%) apresentavam a veia esplênica de igual ou maior calibre que a veia porta (Inversão - grupo de estudo). A média dos diâmetros pré-operatórios das veias porta e esplênica foram, respectivamente, 1,49/1,14cm no grupo controle, e 0,98/1,07cm no grupo de inversão. O diâmetro da veia porta foi significativamente maior no grupo controle quando comparado ao grupo de inversão (p<0,05). A presença de varizes de fundo gástrico foi identificada em 33,3% do grupo de inversão e em 38,5% dos pacientes do grupo controle. Recidiva hemorrágica pós-operatória ocorreu em 23,1% dos pacientes do grupo de inversão e em 13,4% no grupo controle (p>0,05). Na avaliação pós-operatória com ultrassonografia Doppler de vasos portais, não houve casos de trombose portal no grupo de inversão, e no grupo controle a trombose portal foi identificada em 16,9% dos pacientes (p<0,05). O óbito ocorreu em um (4,8%) paciente do grupo inversão, e a mortalidade foi de 4,1% no grupo controle (p>0,05). A média do nível sérico de plaquetas foi significativamente menor (65.950\mm□) no grupo de inversão do que no grupo controle (106.647\mm□) (p<0,05). CONCLUSÃO: Os resultados sugerem que a inversão do calibre veia porta\esplênica não representa uma contraindicação ao tratamento cirúrgico da hipertensão portal esquistossomótica.
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OBJECTIVE: to determine the incidence of deep vein thrombosis and prophylaxis quality in hospitalized patients undergoing vascular and orthopedic surgical procedures. METHODS: we evaluated 296 patients, whose incidence of deep venous thrombosis was studied by vascular ultrasonography. Risk factors for venous thrombosis were stratified according the Caprini model. To assess the quality of prophylaxis we compared the adopted measures with the prophylaxis guidelines of the American College of Chest Physicians. RESULTS: the overall incidence of deep venous thrombosis was 7.5%. As for the risk groups, 10.8% were considered low risk, 14.9%moderate risk, 24.3% high risk and 50.5% very high risk. Prophylaxis of deep venous thrombosis was correct in 57.7%. In groups of high and very high risk, adequate prophylaxis rates were 72.2% and 71.6%, respectively. Excessive use of chemoprophylaxis was seen in 68.7% and 61.4% in the low and moderate-risk groups, respectively. CONCLUSION: although most patients are deemed to be at high and very high risk for deep vein thrombosis, deficiency in the application of prophylaxis persists in medical practice.
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OBJECTIVE: To assess hematological and biochemical features of splenic effluent blood and their influence on the rise of hematological values after splenectomy.METHODS: we studied 20 patients undergoing surgical treatment for schistosomatic portal hypertension. We collected blood samples for CBC, coagulation, bilirubin and albumin in the splenic vein (perioperative) and peripheral blood (immediately pre and postoperative periods).RESULTS: the splenic blood showed higher values of red blood cells, hemoglobin, hematocrit, platelet count, total leukocytes, neutrophils, lymphocytes, monocytes, eosinophils and basophils, as well as reduction of laboratory coagulation parameters in relation to peripheral blood collected preoperatively. In the postoperative peripheral blood there was an increase in the overall leukocytes and in their neutrophil component, and decreased levels of basophils, eosinophils and lymphocytes. The other postoperative variables of complete blood count and coagulation tests were not different compared with the splenic blood. The albumin values were lower postoperatively when compared to preoperative and splenic blood. There were higher values of direct bilirubin in the postoperative period when compared with the preoperative and splenic blood. Postoperative indirect bilirubin was lower compared to its value in the splenic blood.CONCLUSION: hematological and biochemical values of splenic effluent blood are higher than those found in peripheral blood in the presence of schistosomal splenomegaly. However, the splenic blood effluent is not sufficient to raise the blood levels found after splenectomy.
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Objective: To evaluate the anatomic topographic relation between the sciatic nerve in relation to the piriform muscle and the posterior portal for the establishment of hip arthroscopy.Methods: We dissected 40 hips of 20 corpses of adult Brazilians, 17 male and three female, six black, six brown and eight white. We studied the anatomical relationship between the sciatic nerve and the piriform muscle with their variations and the distance between the lateral edge of the sciatic nerve and the posterior portal used in hip arthroscopy. We then classified the anatomical alterations found in the path of the sciatic nerve on the piriform muscle.Results: Seventeen corpses had bilateral relationship between the sciatic nerve and the piriform muscle, i.e., type A. We found the following anatomical variations: 12.5% of variant type B; and an average distance between the sciatic nerve and the portal for arthroscopy of 2.98cm. One body had type B anatomical variation on the left hip and type A on the right.Conclusion: the making of the posterior arthroscopic portal to the hip joint must be done with careful marking of the trochanter massive; should there be difficult to find it, a small surgical access is recommended. The access point to the portal should not exceed two centimeters towards the posterior superior aspect of the greater trochanter, and must be made with the limb in internal rotation of 15 degrees.
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OBJECTIVE: To determine the prevalence of sonographic abnormalities (SA) in the axillary vein of patients with and without post-mastectomy lymphedema. METHODS: We studied a sample of 80 women, divided into two equal groups, with and without lymphedema, with B mode ultrasound, color and pulsed Doppler. The primary variable, SA, is defined as change in the venous diameter, parietal thickening, intraluminal images, compressibility, parietal collapse at inspiration and feature of the axillary venous flow on the operated side. Secondary variables were: stage of lymphedema, surgical technique, number of radio and chemotherapy sessions, limb volume, weight and age. The differences between the proportions in the groups were determined using the Chi-square test and / or Fisher's test. For continuous variables, we used the Mann-Whitney Test. To estimate the magnitude of the associations, we used the prevalence rate of SA in both groups as a measure of frequency, and as a measure of association, the prevalence ratio (PR) obtained as a function of relative risk (RR) and estimated by the test Mantel-Haenszel homogeneity test. We adopted the statistical significance level of 5% (p < 0.05). RESULTS: only the criterion "parietal thickening" was strongly associated with the lymphedema group (p = 0.001). The prevalence of SA was 55% in patients with lymphedema and 17.5% in the group without it, with difference in prevalence of 37.5%. CONCLUSION: the prevalence of SA was higher in patients undergoing mastectomy with lymphedema than in those without lymphedema.
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OBJECTIVE: To evaluate the efficacy of surgical treatment of varicose veins with preservation of the great saphenous vein. METHODS: We conducted a prospective study of 15 female patients between 25 and 55 years of age with clinical, etiologic, anatomic and pathophysiologic (CEAP) classification 2, 3 and 4. The patients underwent surgical treatment of primary varicose veins with great saphenous vein (GSV) preservation. Doppler ultrasonography exams were carried out in the first and third months postoperatively. The form of clinical severity of venous disease, Venous Clinical Severity Score (VCSS) was completed before and after surgery. We excluded patients with history of deep vein thrombosis, smoking or postoperatively use of elastic stockings or phlebotonics. RESULTS: All patients had improved VCSS (p <0.001) and reduction in the diameter of the great saphenous vein (p <0.001). There was a relationship between VCSS and the GSV caliber, as well as with preoperative CEAP. There was improvement in CEAP class in nine patients when compared with the preoperative period (p <0.001). CONCLUSION: The varicose vein surgery with preservation of the great saphenous vein had beneficial effects to the GSV itself, with decreasing caliber, and to the symptoms when the vein had maximum caliber of 7.5 mm, correlating directly with the CEAP. The decrease in GSV caliber, even without complete abolition of reflux, leads to clinical improvement by decreasing the reflux volume.
Multiple scales analysis of nonlinear oscillations of a portal frame foundation for several machines
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An analytical study of the nonlinear vibrations of a multiple machines portal frame foundation is presented. Two unbalanced rotating machines are considered, none of them resonant with the lower natural frequencies of the supporting structure. Their combined frequencies is set in such a way as to excite, due to nonlinear behavior of the frame, either the first anti-symmetrical mode (sway) or the first symmetrical mode. The physical and geometrical characteristics of the frame are chosen to tune the natural frequencies of these two modes into a 1:2 internal resonance. The problem is reduced to a two degrees of freedom model and its nonlinear equations of motions are derived via a Lagrangian approach. Asymptotic perturbation solutions of these equations are obtained via the Multiple Scales Method.
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We apply the Bogoliubov Averaging Method to the study of the vibrations of an elastic foundation, forced by a Non-ideal energy source. The considered model consists of a portal plane frame with quadratic nonlinearities, with internal resonance 1:2, supporting a direct current motor with limited power. The non-ideal excitation is in primary resonance in the order of one-half with the second mode frequency. The results of the averaging method, plotted in time evolution curve and phase diagrams are compared to those obtained by numerically integrating of the original differential equations. The presence of the saturation phenomenon is verified by analytical procedures.
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Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014
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The vasorelaxant effects of SR 47063 (4-(2-cyanimino-1,2-dihydropyrid-1-yl)-2,2-dimethyl-6-nitrochromene), a new K+-channel opener structurally related to levcromakalim, were examined in isolated human saphenous vein (HSV) and rat aorta (RA). HSV or RA rings were precontracted with either KCl or noradrenaline and cumulative relaxant concentration-response curves were obtained for SR 47063 (0.1 nM to 1 µM) in the presence or absence of 3 µM glibenclamide. SR 47063 potently relaxed HSV and RA precontracted with 20 mM (but not 60 mM) KCl or 10 µM noradrenaline in a concentration-dependent manner, showing slightly greater activity in the aorta. The potency of the effect of SR 47063 on HSV and RA was 12- and 58-fold greater, respectively, than that reported for the structurally related K+-channel opener levcromakalim. The vasorelaxant action of SR 47063 in both blood vessels was strongly inhibited by 3 µM glibenclamide, consistent with a mechanism of action involving ATP-dependent K+-channels.
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Bone marrow contains a population of stem cells that can support hematopoiesis and can differentiate into different cell lines including adipocytes, osteocytes, chondrocytes, myocytes, astrocytes, and tenocytes. These cells have been denoted mesenchymal stem cells. In the present study we isolated a cell population derived from the endothelium and subendothelium of the umbilical cord vein which possesses morphological, immunophenotypical and cell differentiation characteristics similar to those of mesenchymal stem cells isolated from bone marrow. The cells were isolated from three umbilical cords after treatment of the umbilical vein lumen with collagenase. The cell population isolated consisted of adherent cells with fibroblastoid morphology which, when properly stimulated, gave origin to adipocytes and osteocytes in culture. Immunophenotypically, this cell population was found to be positive for the CD29, CD13, CD44, CD49e, CD54, CD90 and HLA-class 1 markers and negative for CD45, CD14, glycophorin A, HLA-DR, CD51/61, CD106, and CD49d. The characteristics described are the same as those presented by bone marrow mesenchymal stem cells. Taken together, these findings indicate that the umbilical cord obtained from term deliveries is an important source of mesenchymal stem cells that could be used in cell therapy protocols.
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The objective of the present study was to determine the levels of amino acids in maternal plasma, placental intervillous space and fetal umbilical vein in order to identify the similarities and differences in amino acid levels in these compartments of 15 term newborns from normal pregnancies and deliveries. All amino acids, except tryptophan, were present in at least 186% higher concentrations in the intervillous space than in maternal venous blood, with the difference being statistically significant. This result contradicted the initial hypothesis of the study that the plasma amino acid levels in the placental intervillous space should be similar to those of maternal plasma. When the maternal venous compartment was compared with the umbilical vein, we observed values 103% higher on the fetal side which is compatible with currently accepted mechanisms of active amino acid transport. Amino acid levels of the placental intervillous space were similar to the values of the umbilical vein except for proline, glycine and aspartic acid, whose levels were significantly higher than fetal umbilical vein levels (average 107% higher). The elevated levels of the intervillous space are compatible with syncytiotrophoblast activity, which maintain high concentrations of free amino acids inside syncytiotrophoblast cells, permitting asymmetric efflux or active transport from the trophoblast cells to the blood in the intervillous space. The plasma amino acid levels in the umbilical vein of term newborns probably may be used as a standard of local normality for clinical studies of amino acid profiles.