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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Pancreaticoduodenal preservation and transplantation an experimental study /

Hee, R. van. January 1973 (has links)
Thesis (doctoral)--Katholieke Universiteit van Nijmegen.
2

Experimental studies on vascularized pancreas transplantation in the diabetic rat

Nolan, M. S. R. January 1985 (has links)
No description available.
3

Foetal pancreas transplantation in the rat

Garvey, J. F. W. January 1980 (has links)
No description available.
4

Efeitos da ligadura, livre drenagem de secreções para o peritôneo e oclusão do ducto pancreático com prolamina sobre os componentes exócrino e endócrino do pâncreas de coelhos : estudo clínico, laboratorial e histopatológico /

Kuczynski, Lauro Bogodar. January 2003 (has links)
Orientador: César Tadeu Spadella / Resumo: Nas ressecções pancreáticas por pancreatite crônica, o pâncreas remanescente poderá sofrer novos surtos de pancreatite, em gravidade variável. Nas ressecções por tumores ou pancreatite, a mais comum complicação é a fístula pancreática, com suas conseqüentes morbidade e mortalidade. Nos transplantes pancreáticos, a drenagem da parte exócrina do enxerto para o intestino ou para a bexiga, além das peculiaridades técnicas da execução, não é isenta de diversas complicações. Visando evitar ou atenuar tais conseqüências e simplificar a técnica cirúrgica, têm sido usadas outras abordagens para o tratamento do coto/enxerto pancreático: drenagem livre das secreções com o ducto pancreático aberto, ligadura ductal e oclusão do ducto com polímeros. O propósito de nossa investigação foi estudar os efeitos clínicos, laboratoriais e histopatológicos destes procedimentos sobre os componentes endócrino e exócrino do pâncreas em coelhos... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: After pancreatic ressections due to chronic pancreatitis the remnant pancreas can lead to new outbreaks of pancreatitis in variable degrees of severity. After the resections by tumors or pancreatitis, the most common complication are the pancreatic fistulas with their resultant morbidity and mortality. In the pancreas transplantation the bowel or bladder drainage of the exocrine part of the graft, beyond the technical peculiarities of the execution, is not exempt of several complications. In order to avoid or reduce such consequences and trying to simplify the surgical technique, there have been used other approaches for the treatment of the pancreatic stump/graft: free drainage of the secretions with the duct left open, ductal ligature and duct occlusion with polymers. The proposal of our investigation was to study the clinical, laboratorial and histopathological effects of these procedures in the endocrine and exocrine compounds of the rabbit pancreas... (Complete abstract, click electronic address below) / Doutor
5

Preclinical assessment of the immunosuppressive properties of an anti-CD4 monoclonal antibody (MAB) in an allogeneic foetal rat pancreatic transplantation model

Muller, Christo John Frederick 12 1900 (has links)
Dissertation (PhD)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: Introduction Despite advances in insulin therapy, the side effects associated with diabetes mellitus still remain. Pancreas transplantation has benefited diabetics with end-stage renal failure by reversing the diabetic state and preventing or reversing the progression of diabetes associated diseases. Currently the side effects associated with lifelong immunosuppression preclude pancreas transplantation as a viable treatment option for both type I and II diabetics. In the laboratory, transplanted rat foetal pancreata have been shown to be able to reverse the clinical signs of streptozotocin-induced diabetes in an isogeneic model. Reversal of diabetes by allogeneic foetal rat pancreas transplantation, although possible has proved to be more difficult due to fierce rejection of the grafts and the diabetogenic effects of conventional immunosuppressants. Aims One of the goals, focus and intentions of this laboratory study in rodents, is to contribute new information to the scientific literature. The potential to “reverse” the diabetic state by allogeneic foetal pancreatic transplantation, was the main stimulus for this study. Methods Foetal pancreata of 16-18 days gestation were transplanted into a surgically prepared renal subcapsular space. Immunosuppressive protocols used to prevent rejection of the allogeneic foetal rat pancreata included donor specific transfusion (DST), cyclosporine [a calcineurin inhibitor (CsA)], mycophenolate mofetil [a purine syntase inhibitor (MMF)], and a mouse anti-rat CD4 monoclonal antibody (W3/25). Immunosuppressants were used as monotherapies and in combination. Results Isogeneic foetal rat pancreas transplantation resulted in the growth and development of mature insulin producing islets of Langerhans at the site of engraftment. Allogeneic foetal pancreatic transplantation without immunosuppression resulted in complete rejection of the grafts at 14 days post-transplantation. Histological assessment of allografts at 14 and 30 days post-transplantation showed that CsA was able to prevent acute rejection in our rat models although graft scores and survival were improved if CsA was combined with MMF. Intraperitoneal anti-CD4 monoclonal injections were well tolerated, and if given daily effectively prolonged graft survival up to 30 days. Combining DST with anti-CD4 and CsA induction therapy provided long-term graft survival without daily immunosuppression. This combination, together with allogeneic foetal rat pancreas transplantation, was effective in reversing the clinical signs of experimentally induced diabetes. To my knowledge these are the first published results in which reversal of streptozotocin induced diabetes was achieved by fully MHC mismatched foetal rat pancreatic transplantation. Conclusion Foetal rat pancreatic transplantation is a potential source of endocrine replacement, which, with effective immunosuppression allows for the development of functional islets able to reverse the clinical signs of experimentally induced diabetes in an allogeneic rat model. An unique immunosuppressive protocol, with potential clinical relevance in the human, combines anti-CD4 mAb, CsA and DST induction therapy, which alleviates the burden of daily immunosuppression and associated side effects. / AFRIKAANSE OPSOMMING: Inleiding Ten spyte van die vordering met modeme insulienterapie bly die newe-effekte, waarmee diabetes mellitus geassosieer is, steeds ‘n probleem vir diabete. Diabetiese pasiente met eindstadium nierversaking trek geweldig voordeel uit nier-pankreasoorplantings wat die diabetes omkeer en die progressie van diabetesverwantesiektes voorkom of selfs omkeer. Die newe-effekte van lewenslange immuunonderdrukking skakel pankreasoorplanting uit as ‘n lewensvatbare behandelingsopsie vir tipe I of II diabete. In ‘n streptozotosien-gei'nduseerde diabetiese rotmodel kan isogenei'ese fetale pankreasoorplanting die kliniese tekens van diabetes omkeer. Die omkering van streptozotosien-gei'nduseerde diabetes deur allogeneiese fetale pankreasoorplanting behoort moontlik te wees indien verwerping en die diabetogeniese newe-effekte van konvensionele immuunonderdrukkers oorkom word. Doelstellings Een van die mikpunte, fokusse en oogmerke van hierdie laboratorium studie in knaagdiere, is om ‘n betekenisvolle bydrae tot nuwe kennis in die wetenskaplike literatuur, te maak. Die potensiaal om die diabetiese toestand deur allogeneiese fetale pankeasoorplanting om te keer, was die hoof stimulus vir die studie. Metodes Fetale rotpankreata van 16-18 dae gestasie was in ‘n chirurgies voorbereide spasie onder die nierkapsel oorgeplant. Immuunonderdrukkende protokolle, vir die voorkomming van verwerping van die allogeneiese fetale pankreasoorplantings, het donorspesifiekeoortappings (DST), siklosporien [‘n kalsineurien inhibitor (CsA)], mikofenolaat mofetiel [‘n purien sintase inhibitor (MMF)] en ‘n anti-rot CD4 monoklonale antiliggaam (W3/25) ingesluit. Die immuunonderdrukkers is as mono- of as kombinasieterapie gebruik. Resultate IsogeneTese fetale rotpankreasoorplanting het tot die ontwikkeling van volwasse insulienproduseerende eilande van Langerhans gelei, wat die kliniese tekens van streptozotosien-gei'nduseerde diabetes kon omkeer. Allogenei'ese fetale rotpankreasoorplanting sonder immuunonderdrukking het tot algehele verwerping van die oorplanting binnel4 dae na oorplanting gelei. Histologiese beoordeling van die oorplantings 14 en 30 dae na oorplanting het getoon dat CsA akute verwerping van fetale pankreasoorplantings in die rotmodelle voorkom. Indien CsA met MMF gekombineer word, word die oorplantings-telling en oorlewing verbeter. Intraperitoneale anti-CD4 monoklonale inspuitings was goed verdra, en indien daagliks toegedien, het dit die oorlewing van die pankreasoorplantings effektief tot 30 dae verleng. Die kombinasie van DST, anti-CD4 en CsA induksieterapie het tot langtermyn oorlewing van die pankreasoorplantings gelei sonder verdere daaglikse immuunonderdrukking. Die induksieterapie in kombinasie met allogenei'ese fetale pankreasoorplanting was effektief in die omkering van die kliniese tekens van streptozotosien-gei'nduseerde diabetes in die rot. Hierdie is, sover ek weet, die eerste keer dat omkering van streptozotosien-gei'nduseerde diabetes suksesvol met ‘n volledige MHC onverenigbare allogenei'ese fetale pankreasoorplanting behaal is. Gevolgtrekkings Fetale rotpankreasoorplanting is ‘n potensiele bron vir endokrien vervangingsterapie, wat met effektiewe immuunonderdrukking tot die ontwikkeling van funksionele eilande van Langerhans lei, wat die vermoe het om die kliniese tekens van experimenteel-ge'induseerde diabetes in ‘n allogeneiese rotmodel om te keer. ‘n Unieke immuunonderdrukkingsprotokol, met kliniese relevansie, kombineer DST met anti-CD4 mAb en CsA induksieterapie wat die las van daaglikse immuunonderdrukking en die geassosieerde newe-effekte van konvensionele immuunonderdrukking verlig.
6

Efeitos da ligadura, livre drenagem de secreções para o peritôneo e oclusão do ducto pancreático com prolamina sobre os componentes exócrino e endócrino do pâncreas de coelhos: estudo clínico, laboratorial e histopatológico

Kuczynski, Lauro Bogodar [UNESP] January 2003 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:30:52Z (GMT). No. of bitstreams: 0 Previous issue date: 2003Bitstream added on 2014-06-13T18:41:02Z : No. of bitstreams: 1 kuczynski_lb_dr_botfm.pdf: 2548402 bytes, checksum: ff27d7551d7a419be61cd511e4dedf1e (MD5) / Nas ressecções pancreáticas por pancreatite crônica, o pâncreas remanescente poderá sofrer novos surtos de pancreatite, em gravidade variável. Nas ressecções por tumores ou pancreatite, a mais comum complicação é a fístula pancreática, com suas conseqüentes morbidade e mortalidade. Nos transplantes pancreáticos, a drenagem da parte exócrina do enxerto para o intestino ou para a bexiga, além das peculiaridades técnicas da execução, não é isenta de diversas complicações. Visando evitar ou atenuar tais conseqüências e simplificar a técnica cirúrgica, têm sido usadas outras abordagens para o tratamento do coto/enxerto pancreático: drenagem livre das secreções com o ducto pancreático aberto, ligadura ductal e oclusão do ducto com polímeros. O propósito de nossa investigação foi estudar os efeitos clínicos, laboratoriais e histopatológicos destes procedimentos sobre os componentes endócrino e exócrino do pâncreas em coelhos... / After pancreatic ressections due to chronic pancreatitis the remnant pancreas can lead to new outbreaks of pancreatitis in variable degrees of severity. After the resections by tumors or pancreatitis, the most common complication are the pancreatic fistulas with their resultant morbidity and mortality. In the pancreas transplantation the bowel or bladder drainage of the exocrine part of the graft, beyond the technical peculiarities of the execution, is not exempt of several complications. In order to avoid or reduce such consequences and trying to simplify the surgical technique, there have been used other approaches for the treatment of the pancreatic stump/graft: free drainage of the secretions with the duct left open, ductal ligature and duct occlusion with polymers. The proposal of our investigation was to study the clinical, laboratorial and histopathological effects of these procedures in the endocrine and exocrine compounds of the rabbit pancreas... (Complete abstract, click electronic address below)
7

Peri-operative assessment and optimisation in simultaneous pancreas and kidney transplantation

Khambalia, Hussein January 2016 (has links)
Pancreas transplantation (PT) is considered a gold-standard cure for brittle insulin dependent diabetes mellitus. In over 90% of cases, this is conducted simultaneously with a kidney transplant, providing concurrent treatment for end-stage renal failure (Simultaneous pancreas and kidney transplantation, SPKT). However, since its inception in the 1960’s, SPKT has been associated with considerable morbidity and mortality. Despite significant recent improvements in graft and patient survival, the multi-factorial nature of the procedure has resulted in persistently high peri-operative morbidity. This thesis has identified four areas to study in the peri-operative assessment and management of these patients, potentially resulting in improved clinical outcomes. 1. Pre-operative risk-prediction scoring systems aide in the consent process and the peri-operative planning of care following major surgery. In PT, multi-system risk-prediction tools are deficient. We therefore assessed the utility of commonly used general surgical risk prediction models in PT recipients. Our finding suggested that The Waterlow Score, a multi-system tool originally developed for predicting the development of decubitus skin ulcers, identified high-risk individuals and has value in predicting outcome following SPKT.2. Peri-operative physiological optimisation (Goal-directed therapy, GDT) is well-recognised to improve outcomes following major general surgery in high-risk individuals. A randomised controlled trial was therefore performed to investigate the benefits of GDT in the peri-operative period following SPKT. The findings demonstrated improved short-term outcomes following GDT in our cohort.3. The temporal evolution of biomarkers following major physiological stresses allow for application in the diagnosis, management surveillance and treatment of diseases. In our cohort the acute evolution of inflammatory and diabetes biomarkers were delineated and correlated to clinical outcome. We identified that cold ischaemic time is significantly negatively related to early pancreatic function and CRP provides an easily measurable predictor of recipient morbidity.4. The final study aimed to evaluate the feasibility and assess the benefits of contrast enhanced ultrasound (CEUS) in the immediate post-operative period following PT. We found CEUS to be a clinically useful adjunct in the post-operative assessment of allograft morphology and perfusion, although further validation and correlation with outcomes is required.
8

Métodos seccionais de imagem na avaliação do transplante de pâncreas / Sectional imaging evaluation on pancreas transplantation

Guimarães Junior, Paulo Ivan Ferreira 02 June 2017 (has links)
Introdução: O transplante de pâncreas é uma opção terapêutica para pacientes portadores de diabetes mellitus, quando bem indicado, com objetivo de restaurar a normoglicemia sem necessidade de uso de insulina, sendo que a técnica mais utilizada é o transplante simultâneo pâncreas-rim. Houve aumento da indicação e realização deste procedimento em todo o mundo nos últimos anos, crescendo a importância de se conhecer os aspectos de imagem no pré e pós-transplante de pâncreas. Objetivos: Avaliar e discutir o papel das diferentes modalidades de exames de imagem empregadas na avaliação no pré e pós-transplante de pâncreas enfatizando os achados normais e das possíveis complicações. Propor um fluxograma para realização de exames de imagem para o programa de transplante de pâncreas considerando a casuística apresentada. Metodologia: Levantamento retrospectivo dos métodos de imagem com as indicações e os achados pré e pós-procedimento em todos os pacientes submetidos a transplante de pâncreas no Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto, da Universidade de São Paulo. Resultados: Foram estudados 14 casos com indicação de transplante simultâneo pâncreasrim, 13 destes submetidos ao transplante no período 2010-2016, os quais apresentaram idade média de 37,6 +/- 6,2 anos (variando entre 24 e 51 anos), sendo 8 (57%) do sexo masculino e 6 (42%) do sexo feminino. Um (7,2%) paciente não pode receber o enxerto pancreático devido a procedimento cirúrgico frustro resultante de diagnóstico intra-operatório de placa ateromatosa extensa. As complicações pós-transplante mais comuns foram: coleções na 7 cavidade abdominal (6/13 casos (46,1%)), pancreatite (6/13 (46,1%)) e complicações vasculares (4/13 (30,8%)). O US com Doppler foi realizado no pós-operatório em todos os casos. Conclusões: há necessidade de avaliação vascular pré-operatória por imagem do receptor, de rotina, para evitar problemas no momento do transplante. O TSPR tem alto risco de complicações, sendo necessária a retirada do enxerto em número relativamente grande dos casos. A avaliação pelos métodos de imagem foi fundamental para o diagnóstico e planejamento do tratamento das complicações, sendo que o US com Doppler se mostrou suficiente como primeiro exame. A correlação com angioTC e(ou) angioRM foi necessária nos casos com suspeita de complicação vascular, permitindo confirmar a suspeita em todos os casos. / Introduction: Pancreas transplantation is a therapeutic option for patients with diabetes mellitus, when well indicated, to restore normoglycemia with no need of insulin, and the most commonly used technique is simultaneous pancreas-kidney transplantation. There has been an increase in the indication and performance of this procedure worldwide in recent years, increasing the importance of knowing the aspects of imaging in the pre- and posttransplantation of pancreas. Objectives: To evaluate and discuss the role of the different imaging modalities used in the assessment in the pre- and post transplantation of the pancreas emphasizing the normal findings and the possible complications. To propose a flowchart to perform imaging tests for the pancreas transplantation program considering the presented case series. Methodology: Retrospective survey of imaging methods with pre and post-procedure indications and findings in all patients undergoing pancreas transplantation at Hospital das Clínicas, Ribeirão Preto Medical School, University of São Paulo. Results: We studied 14 cases with simultaneous pancreas-kidney transplantation, 13 of them undergoing transplantation in the period 2010-2016, which presented a mean age of 37.6 +/- 6.2 years (ranging from 24 to 51 years), of which 8 (57%) were male and 6 (42%) were female. One (7,2%) patient could not receive the pancreatic graft due to the frustrating surgical procedure resulting from an intraoperative diagnosis of extensive atheromatous plaque. The most common post-transplant complications were collections in the abdominal 9 cavity (6/13 cases (46.1%)), pancreatitis (6/13 (46.1%)) and vascular complications (4/13 (30.8% )). The US with Doppler was performed postoperatively in all cases. Conclusions: There is a need for routine preoperative vascular imaging of the recipient to avoid problems at the time of transplantation. TSPR has a high risk of complications, requiring removal of the graft in a relatively large number of cases. The evaluation by the imaging methods was fundamental for the diagnosis and planning of the treatment of the complications, and the US with Doppler was sufficient as the first examination. Correlation with angioTC and (or) angioRM was necessary in cases with suspected vascular complications, allowing confirmation of suspicion in all cases.
9

Contribuição do meio de contraste ultra-sonográfico na avaliação do pâncreas transplantado / Contribution of sonographic contrast media in assessment of pancreatic transplantation

Antonio Sergio Zafred Marcelino 25 February 2008 (has links)
INTRODUÇÃO: O transplante de pâncreas é a opção definitiva para a manutenção do estado normoglicêmico permanente nos portadores de diabetes mellitus tipo 1. O meio de contraste de ultra-som é uma metodologia capaz de avaliar a perfusão tecidual, mas não há um estudo para a avaliação do padrão de perfusão do pâncreas transplantado normal e patológico. A importância da avaliação da perfusão do enxerto e a aplicação do meio de contraste por microbolhas foram os motivos para a realização desta pesquisa. Este estudo, desenvolvido no Instituto de Radiologia do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo no período de novembro de 2004 a setembro de 2006 objetivou: A) estabelecer os padrões de vascularização do enxerto nos pacientes normais e naqueles com suspeita de complicações; B) comparar os achados de exames laboratoriais, uso ou não de insulina exógena e situação clínica dos pacientes com os achados da ultra-sonografia modo-B e com meio de contraste por microbolhas; C) Estabelecer o valor da ultra-sonografia com meio de contraste de microbolhas (USMCM) na avaliação do pâncreas transplantado. CASUÍSTICA e MÉTODOS: Vinte e seis pacientes foram submetidos ao exame de ultra-sonografia com contraste em um total de trinta estudos, 20 (66,7%) em homens e 10 (33,3%) em mulheres. A idade dos pacientes variou de 25 a 51 anos, com média de idade de 40 anos (+ 7,3 anos). O tempo médio da realização do transplante até a realização do estudo variou de um dia a 63 meses (mediana de 24 meses). Ao modo-B, o pâncreas foi analisado quanto a ecogenicidade, dimensões (avaliação qualitativa e quantitativa) e contornos. Após a administração do meio de contraste, observou-se o tempo de chegada do meio de contraste no pâncreas, o padrão e a intensidade de realce. Após esta avaliação foi realizada uma classificação baseada nos achados do modo-B e contraste nas seguintes possibilidades: padrão de perfusão normal, alterações agudas (rejeição, pancreatite ou trombose) ou alterações crônicas (rejeição crônica). RESULTADOS: Observou-se associação estatisticamente significante entre a ecogenicidade e a situação clínica (p=0,010); ecogenicidade e uso de insulina (p= 0,021); dimensões (avaliação qualitativa) e situação clinica (p=0,011); dimensões (avaliação qualitativa) e uso de insulina (p=0,028); padrão de realce (p=0,024) e intensidade do realce com a situação clínica (p=0,039). Houve associação estatisticamente significante também entre o uso ou não de insulina exógena com a perfusão do enxerto (p=0,014) e a hipótese diagnóstica (ultra-som) (p=0,001). CONCLUSÃO: Os padrões de vascularização do pâncreas transplantado normais e naqueles com suspeita de complicações foram estabelecidos. Os critérios de ecogenicidade e a avaliação qualitativa das dimensões do pâncreas ao ultra-som modo-B se mostraram adequados na diferenciação entre estudos normais e alterados. A ultra-sonografia com meio de contraste de microbolhas foi útil na diferenciação entre estudos normais e alterados do pâncreas transplantado, utilizando os critérios de padrão do realce, intensidade do realce e perfusão do enxerto na fase arterial. / INTRODUCTION: Pancreatic transplantation is the long-term therapeutic option for maintaining normoglycemic status in patients with type 1 diabetes mellitus. Sonographic contrast medium allows to evaluate tissue perfusion but there are no studies comparing this parameter in normal and pathologic pancreatic grafts in the literature at the time of this writing. The importance of assessment of graft perfusion and the potential role of contrast-enhanced sonography with microbubbles in this regard were the reasons for this research. The study conducted at the Instituto de Radiologia do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo between November, 2004 and September, 2006 had the following objectives: A) to establish patterns of graft vascularization in normal patients and in those with suspected abnormalities; B) to compare grayscale mode and contrastenhanced sonographic findings with clinical status, laboratory results, and need for exogenous insulin; C) to define the role of contrast-enhanced sonography with microbubbles in the evaluation of pancreatic transplantation.MATERIALS AND METHODS: Twenty-six patients underwent a total of 30 sonographic examinations with microbubbles, 20 (66.7%) men and 10 (33.3%) women. Age range was 25 to 51 years, with a mean of 40 years (+ 7.3 years). Time elapsed between transplantation and imaging ranged from 1 day to 63 months (median, 24 months). Using grayscale mode, pancreas was assessed for echogenicity, dimensions (both quantitatively and qualitatively) and contours. Following intravenous contrast medium administration, time for enhancement of the pancreatic graft, pattern and intensity of enhancement were documented. A classification system based on grayscale and contrast-enhanced sonographic findings was designed, with the following categories: normal perfusion pattern, acute changes (rejection, pancreatitis or thrombosis) and chronic changes (chronic rejection). RESULTS: There was a statistically significant association between echogenicity and clinical status (p=0.010); echogenicity and need for exogenous insulin (p=0.021); dimensions (qualitative criteria) and clinical status (p=0.011); dimensions (qualitative criteria) and need for exogenous insulin (p=0.028); pattern (p=0.024) and intensity of enhancement versus clinical status (p=0.039). There was also statistically significant association between need for exogenous insulin and graft perfusion (p=0.014), and sonography-based diagnosis (p=0.001). CONCLUSION: The study provided patterns of vascularization in normal pancreatic grafts and in patients with suspected abnormalities. Distinction of normal and abnormal pancreatic grafts was possible using echogenicity and qualitative analysis of graft size on grayscale mode. Contrast-enhanced sonography with microbubbles also contributed to differentiation between normal and abnormal pancreatic grafts, using pattern and intensity of enhancement and perfusion of the graft during the arterial phase.
10

Contribuição do meio de contraste ultra-sonográfico na avaliação do pâncreas transplantado / Contribution of sonographic contrast media in assessment of pancreatic transplantation

Marcelino, Antonio Sergio Zafred 25 February 2008 (has links)
INTRODUÇÃO: O transplante de pâncreas é a opção definitiva para a manutenção do estado normoglicêmico permanente nos portadores de diabetes mellitus tipo 1. O meio de contraste de ultra-som é uma metodologia capaz de avaliar a perfusão tecidual, mas não há um estudo para a avaliação do padrão de perfusão do pâncreas transplantado normal e patológico. A importância da avaliação da perfusão do enxerto e a aplicação do meio de contraste por microbolhas foram os motivos para a realização desta pesquisa. Este estudo, desenvolvido no Instituto de Radiologia do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo no período de novembro de 2004 a setembro de 2006 objetivou: A) estabelecer os padrões de vascularização do enxerto nos pacientes normais e naqueles com suspeita de complicações; B) comparar os achados de exames laboratoriais, uso ou não de insulina exógena e situação clínica dos pacientes com os achados da ultra-sonografia modo-B e com meio de contraste por microbolhas; C) Estabelecer o valor da ultra-sonografia com meio de contraste de microbolhas (USMCM) na avaliação do pâncreas transplantado. CASUÍSTICA e MÉTODOS: Vinte e seis pacientes foram submetidos ao exame de ultra-sonografia com contraste em um total de trinta estudos, 20 (66,7%) em homens e 10 (33,3%) em mulheres. A idade dos pacientes variou de 25 a 51 anos, com média de idade de 40 anos (+ 7,3 anos). O tempo médio da realização do transplante até a realização do estudo variou de um dia a 63 meses (mediana de 24 meses). Ao modo-B, o pâncreas foi analisado quanto a ecogenicidade, dimensões (avaliação qualitativa e quantitativa) e contornos. Após a administração do meio de contraste, observou-se o tempo de chegada do meio de contraste no pâncreas, o padrão e a intensidade de realce. Após esta avaliação foi realizada uma classificação baseada nos achados do modo-B e contraste nas seguintes possibilidades: padrão de perfusão normal, alterações agudas (rejeição, pancreatite ou trombose) ou alterações crônicas (rejeição crônica). RESULTADOS: Observou-se associação estatisticamente significante entre a ecogenicidade e a situação clínica (p=0,010); ecogenicidade e uso de insulina (p= 0,021); dimensões (avaliação qualitativa) e situação clinica (p=0,011); dimensões (avaliação qualitativa) e uso de insulina (p=0,028); padrão de realce (p=0,024) e intensidade do realce com a situação clínica (p=0,039). Houve associação estatisticamente significante também entre o uso ou não de insulina exógena com a perfusão do enxerto (p=0,014) e a hipótese diagnóstica (ultra-som) (p=0,001). CONCLUSÃO: Os padrões de vascularização do pâncreas transplantado normais e naqueles com suspeita de complicações foram estabelecidos. Os critérios de ecogenicidade e a avaliação qualitativa das dimensões do pâncreas ao ultra-som modo-B se mostraram adequados na diferenciação entre estudos normais e alterados. A ultra-sonografia com meio de contraste de microbolhas foi útil na diferenciação entre estudos normais e alterados do pâncreas transplantado, utilizando os critérios de padrão do realce, intensidade do realce e perfusão do enxerto na fase arterial. / INTRODUCTION: Pancreatic transplantation is the long-term therapeutic option for maintaining normoglycemic status in patients with type 1 diabetes mellitus. Sonographic contrast medium allows to evaluate tissue perfusion but there are no studies comparing this parameter in normal and pathologic pancreatic grafts in the literature at the time of this writing. The importance of assessment of graft perfusion and the potential role of contrast-enhanced sonography with microbubbles in this regard were the reasons for this research. The study conducted at the Instituto de Radiologia do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo between November, 2004 and September, 2006 had the following objectives: A) to establish patterns of graft vascularization in normal patients and in those with suspected abnormalities; B) to compare grayscale mode and contrastenhanced sonographic findings with clinical status, laboratory results, and need for exogenous insulin; C) to define the role of contrast-enhanced sonography with microbubbles in the evaluation of pancreatic transplantation.MATERIALS AND METHODS: Twenty-six patients underwent a total of 30 sonographic examinations with microbubbles, 20 (66.7%) men and 10 (33.3%) women. Age range was 25 to 51 years, with a mean of 40 years (+ 7.3 years). Time elapsed between transplantation and imaging ranged from 1 day to 63 months (median, 24 months). Using grayscale mode, pancreas was assessed for echogenicity, dimensions (both quantitatively and qualitatively) and contours. Following intravenous contrast medium administration, time for enhancement of the pancreatic graft, pattern and intensity of enhancement were documented. A classification system based on grayscale and contrast-enhanced sonographic findings was designed, with the following categories: normal perfusion pattern, acute changes (rejection, pancreatitis or thrombosis) and chronic changes (chronic rejection). RESULTS: There was a statistically significant association between echogenicity and clinical status (p=0.010); echogenicity and need for exogenous insulin (p=0.021); dimensions (qualitative criteria) and clinical status (p=0.011); dimensions (qualitative criteria) and need for exogenous insulin (p=0.028); pattern (p=0.024) and intensity of enhancement versus clinical status (p=0.039). There was also statistically significant association between need for exogenous insulin and graft perfusion (p=0.014), and sonography-based diagnosis (p=0.001). CONCLUSION: The study provided patterns of vascularization in normal pancreatic grafts and in patients with suspected abnormalities. Distinction of normal and abnormal pancreatic grafts was possible using echogenicity and qualitative analysis of graft size on grayscale mode. Contrast-enhanced sonography with microbubbles also contributed to differentiation between normal and abnormal pancreatic grafts, using pattern and intensity of enhancement and perfusion of the graft during the arterial phase.

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