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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.
11

Avaliação histológica e microtomográfica comparativa entre o aloenxerto ósseo liofilizado e o aloenxerto ósseo congelado para preenchimento na elevação do assoalho de seio maxilar / Histological and microtomografic assessment between lyophilized and fresh-frozen allogenic bone grafts for sinus lifting : Randomized Controlled clinical Trial

Marcello Roberto Manzi 15 September 2016 (has links)
O aloenxerto ósseo desmineralizado irradiado (ALD) e o aloenxerto ósseo congelado mineralizado (ACM) são alternativas ao osso autógeno para o aumento do rebordo ósseo alveolar. Individualmente, já foram testados quanto a eficiência, de certa forma, comparável aos autógenos e suas vantagens sobre eles. Entretanto, não há estudos padronizados comparando o desempenho clínico entre esses dois tipos de aloenxertos, quando utilizados em região de maxila atrófica para instalação e implantes. O objetivo deste estudo foi realizar um ensaio clínico randomizado controlado que envolve a elevação bilateral do seio maxilar empregando o osso alógeno liofilizado desmineralizado irradiado (ALD) ou o osso alógeno congelado mineralizado (ACM) e verificar comparativamente os desfechos clínicos para estabilidade de implantes, quantidade e qualidade de neoformação óssea. Dez pacientes foram submetidos a cirurgia de elevação do seio maxilar bilateral na qual foi utilizado um dos tipos de aloenxerto, de forma randômica em um dos lados. Seis a nove meses após o aumento do rebordo ósseo, no momento da instalação de implantes osseointegrados, foram obtidas amostras ósseas por meio de trefina de 2x10mm para análises microtomográficas e histológicas. A estabilidade dos implantes foi aferida por frequência de ressonância em dois momentos, imediato e após 6 meses da instalação dos implantes. Os resultados mostraram aumento do rebordo, radiograficamente detectável em todos os pacientes e grupos. Os implantes osseointegrados, inseridos em enxertos ACM, apresentaram melhor estabilidade primária, embora o acréscimo de estabilidade tenha sido mais significativo no ALD. As análises microtomográficas e histológicas revelaram mais formação óssea de melhor qualidade nos ALD do que nos ACM. Não houve resposta a corpo estranho para nenhum dos tipos de aloenxertos. Notou-se mais quantidade de material remanescente para ACM do que para ALD. Concluímos que os aloenxertos liofilizados desmineralizados irradiados (ALD) apresentaram melhor desempenho quanto aos parâmetros estudados. / Demineralized bone irradiated allograft (DFDBA) and fresh- frozen (FF) are alternative grafts to autogenous bone in alveolar ridge augmentation. Individually, these allografts have been tested for their efficiency, in a way comparable to autogenous, and so their advantages over autogenous grafts. However, there are no standardized clinical studies comparing the clinical and histological performance between these two allografts in atrophic maxilla bone augmentation for implants instalment. The aim of this study was to perform a randomized controlled clinical trial involving bilateral sinus floor elevation employing demineralized freeze-dried irradiated allograft (DFDBA) or fresh-frozen (FF) and to compare clinical and histological outcomes for stability of implants, quantity and quality of bone formation. Ten patients underwent bilateral maxillary sinus lifting surgery in which side was randomly used one of those allografts for alveolar ridge augmentation. Six to nine months after grafting, at the time of dental implants instalment, trephine 2x10mm bone core biopsies were obtained to micro computed tomographic and histological analyses. The stability of the implants was measured by resonance frequency in two stages, immediately and 6 months after implants installation. Results showed that there was an increase, radiographically detectable, in all patients and groups. The dental implants inserted in FF grafts showed better primary stability but implant stability, lately, increased significantly in DFDBA. Micro tomographic and histological analyses revealed that bone formation amount and quality was superior in DFDBA than in FF. There was no foreign body response for any of the allografts. There was a greater amount of persisting graft-materialin FF than in DFDBA. We conclude that demineralized freeze-dried irradiated allograft (DFDBA) presented a superior performance than mineralized FF.
12

Hyperspectral Imaging (HSI) of Human Kidney Allografts

Wagner, Tristan Cedric 04 January 2022 (has links)
Zusammenfassung der Arbeit /Dissertation zur Erlangung des akademischen Grades Dr. med. Hyperspectral Imaging (HSI) of Human Kidney Allografts Die HSI Bildgebung ist ein nichtinvasives Instrument zur quantitativen Bewertung der Sauerstoffanreicherung parenchymatöser Organe, der Mikroperfusion von Transplantaten sowie zur Messung der Hämoglobin- und Wasserkonzentration von Organen. Aktuell wird die HSI Bildgebung bereits in der neuronalen Funktionsdiagnostik zur detaillierten Gewebedifferenzierung genutzt18 und dient zur Überprüfung der Perfusion komplexer Anastomosen im Bereich der Ösophagus- und der Leberchirurgie31,32. Die ersten Ergebnisse zur Tumordetektion konnten ebenfalls erfolgversprechend publiziert werden20. Ziel unserer Studie war es das Potenzial dieser neuartigen Bildgebungstechnik im Rahmen der Transplantationsmedizin vorzustellen und zu beschreiben. Es sollte gezeigt werden, ob die HSI Analyse für die intraoperative Qualitäts- und Lebensfähigkeitsbewertung bei Nierentransplantationen verwendet werden kann. Generell hat sich die Komplikationsrate nach erfolgter Nierentransplantation in den letzten Jahrzehnten von bis zu 30% auf weniger als 6% verringert6. Die Einschätzung der Organqualität während der Organentnahme oder Implantation, die potentiellen Funktionalität einer Transplantatniere im Rahmen einer postmortal oder auch lebend gespendeten Niere ist jedoch fortwährend schwer33. Im Rahmen der aktuellen Studie, wurden zur Erläuterung der beschriebenen Zielsetzung 17 postmortale Nierentransplantationen mit der hyperspektralen Kamera 15 und 45 Minuten nach Reperfusion fotografiert. Hierbei wurden mithilfe der HSI- Kamera die Gewebeoxygenierung (StO2), die Perfusion (NIR-Perfusionsindex), der OHI (Organ Hämoglobin Index) und der TWI (Tissue-Water-Index, Gehalt des Wassers des Gewebes) erfasst19,31. Revisionseingriffe, wie die Ureterneuimplantation und eine Thrombektomie wurden ebenfalls begleitet und analysiert. Zwei Patienten (11,8%) entwickelten eine Delayed Graft Function (DGF). Als Ergebnis zeigte sich, dass die optisch ermittelte Oxygenierung und Mikroperfusion bei Patienten mit einer DGF in unserer Studie signifikant verringert war. Gleiches galt für den NIR Perfusionsindex. Bei einer postoperativen Ureternekrose wurde ein deutliches NIR-Perfusionsdefizite des nekrotischen Teils dargestellt. Die Bestätigung erfolgte durch die Histopathologie. Wir konnten zeigen, dass eine genaue, quantifizierbare Aussage über die Mikroperfusion im arteriellen sowie venösen Stromgebiet möglich ist. Eine sichere und nicht invasive Untersuchungsmethode ist somit während einer Nierentransplantation integrierbar ohne den Ablauf der Operation zu beeinflussen. Die hyperspektrale Bildgebung ermöglicht somit intraoperativ die Organfunktion während der Transplantation zu bewerten und eine verzögerte Transplantatfunktion vorherzusagen. Als Kritikpunkt an der neuen Methode könnte angeführt werden, dass die Technik der HSI Visualisierung eine direkte Sicht auf die Niere erfordert. Grund dafür ist, dass die derzeitige maximale Eindringtiefe für Mikrozirkulationsmessungen 4 bis 6 Millimeter beträgt. Die intraoperative Sonographie ist aktuell das Einzige vergleichbare, bildgebende, zugelassene und nicht invasive Verfahren zur Bewertung der Organe. Mit der Ultraschalldiagnostik ist die Makroperfusion darstellbar und Vasospasmen sowie Perfusionsdefizite können frühzeitige detektiert werden34. Auf die Mikrozirkulation und die Oxygenierung und mögliche noch chirurgisch behandelbare Perfusionsdefizite, kann jedoch nur bedingt eingegangen werden35. Grundsätzlich hat die Bedeutung der Ultraschalldiagnostik im prä- und postoperativen Verlauf bei Patienten nach Nierentransplantation einen hohen Stellwert. Nichtsdestotrotz könnte die Kombination von Sonographie und HSI die genaue Beschreibung von Mikro- und Makroperfusion optimieren und das Erfassen und Beschreiben der Organqualität verbessern. Grundsätzlich stünde als weitere Alternative zu Bewertung des Organs die Indocyaningrün-Angiographie zur Verfügung. Hier besticht die hyperspektrale Bildgebung jedoch, da keine intravenöse Gabe von Floreszenzen wie Indocyaningrün (ICG) benötigt wird. So sind Wechselwirkungen und allergische Reaktionen ausgeschlossen28. Zusammenfassend wäre die mögliche Weiterentwicklung der Bildgebung in ein video- gestütztes operatives Tool zur Überwachung der Reperfusion und Fertigung diverser Anastomosen ein Meilenstein in der operativen Bildgebung und könnte wegweisenden Erkenntnisse der vaskulären Versorgung generieren. Nach unseren erfolgversprechenden Ergebnissen könnte es bald möglich sein, die Maschinenperfusion, die eine Verbesserung der Graft-Funktion und auch Verbesserung des Gesamtüberlebens bei Nieren- und Lebertransplantation zeigt5,36, mit hyperspektraler Bildgebung zu observieren und noch feiner zu justieren. Die Erkenntnis der HSI Bildgebung ist in Zeiten der Organknappheit7,11 essentiell und unseren Erachtens nur vorteilhaft zu beschreiben.
13

Technické aspekty záchovných operací aortálního kořene:Strukturální změny vzniklé při různých protokolech rozmrazování na lidských kryoprezerovovaných allograftech aortálního kořene a reprodukovatelnost externí aortální anuloplastiky za použití prstence Coroneo. / Technical aspects of aortic root sparing surgery:Structural changes occurring during different thawingprotocols of cryopreserved human aortic root allografts and thereproducibility of external aortic root annuloplasty using Coroneo ring.

Novotný, Róbert January 2019 (has links)
Aortic valve-sparing procedures treating patients with aortic root aneurysm with or without aortic insufficiency and patients with ascending aortic aneurysm and aortic insufficiency are no longer experimental and unproven procedures. A successful aortic valve-sparing or repair operation aims not only to correct the failing part of the aortic root but also to restore the intro- and the inter-component relationship of the aortic root elements to optimal dimensions and relations. The avoidance of anticoagulation therapy and prosthesis-related complications makes aortic valve repair a tempting procedure. Considering the increasing rate of cusp repair reported in scientific literature, conservative aortic valve surgery seems to be developing into aortic valve repair surgery. This Dissertation Theses are devoted to the study of some specific technical aspects of aortic root sparing surgery, namely to the study of structural changes occurring in cryopreserved human aortic root allografts and the reproducibility of Coroneo ring implantation procedure. The Introduction of these Dissertation Theses deals with the general review of aortic valve- sparing operations in the light of the historical aspects of used surgical technique, dynamic anatomy and the current situation. One part of the Introduction is...
14

Immunosuppressive protocol with delayed use of low-dose tacrolimus after aortic transplantation suppresses donor-specific anti-MHC class I and class II antibody production in rats

Matia, Ivan, Fellmer, Peter, Splith, Katrin, Varga, Martin, Adamec, Milos, Kämmerer, Ines, Feldbrügge, Linda, Krenzien, Felix, Hau, Hans-Michael, Atanasov, Georgi, Schmelzle, Moritz, Jonas, Sven 12 May 2014 (has links) (PDF)
Background: Arterial allografts are used as vascular conduits in the treatment of prosthetic graft infection. Immunosuppression decreases their rupture risk rate. However, immunosuppression can be unprofitable in florid infection. Previously, we confirmed inhibition of cell-mediated destruction of rat aortic grafts by delayed use of tacrolimus. In this work, we studied the influence of this protocol on the antibody-mediated rejection.
15

Analyse der Morphologie des Myokards, der Koronararterien und der großen Gefäße von Spenderherzen für Klappenhomografts

Wiegemann, Thomas 28 April 2000 (has links)
317 pathologisch-anatomische Befundberichte über die Morphologie des Myokards, der Koronararterien, der Aorta und der Pulmonalarterien von Herzen, die in der Homograftbank des Deutschen Herzzentrums Berlin in den Jahren 1996 bis 1998 für eine potentielle Klappenspende (Aorten- und Pulmonalklappen) seziert worden waren, wurden ausgewertet. 178 dieser Herzen stammten von Herztransplantatempfängern und zeigten naturgemäß schwere pathologische Veränderungen. Sechs Herzen stammten von Leichen. 133 Herzen waren hirntoten Menschen entnommen worden. Ursprünglich hatte bei vielen dieser 133 Spenderherzen die Absicht bestanden, sie für die Transplantation zu verwenden, was aus verschiedenen Gründen nicht möglich war. Ziel der retrospektiven Studie war die Erfassung der morphologischen Situation der Organe, wobei der Schwerpunkt auf der Gruppe der Spenderherzen lag. / This work contains an analysis of 317 records with a detailed description of the morphology of myocardium, coronary arteries, aortas and pulmonary arteries of hearts dissected for the purpose of harvesting the aortic and pulmonary valves as allografts in the Heart Valve Bank of the German Heart Institute, Berlin, from 1996 through 1998. 178 hearts stemmed from patients who recieved heart transplants. Naturally these organs revealed severe pathologic findings. Cadaveric organs (non beating hearts) amounted to six. 133 hearts were taken from brain dead human beings. Many of these 133 donor organs were originally considered to be potentially usable for transplantation, but were discarded for various reasons. The objective of this retrospective study was to ascertain the morphologic state of the hearts with special focus on the 133 donor hearts.
16

Estudo das células Natural Killer (NK) em biópsias de transplante renal com diagnóstico de rejeição aguda C4d positiva ou negativa / Study of Natural Killer cells (NK) in renal transplant biopsies with positive or negative C4d acute rejection.

Santos, Daniela Cristina dos 26 September 2016 (has links)
INTRODUÇÃO: O objetivo do estudo foi avaliar o perfil de marcadores imuno-histoquímicos relacionados às células NK em biópsias de aloenxertos renais com diagnóstico anatomopatológico de rejeição aguda (mediadas por células T ou anticorpos) e estabelecer relações desses marcadores com parâmetros morfológicos de lesão à microcirculação e sobrevida do enxerto. MÉTODOS: Estudo retrospectivo histórico que revisou 74 biópsias realizadas entre janeiro de 2009 e dezembro de 2012, de pacientes com rejeição aguda mediada por células T (n=36), rejeição aguda mediada por anticorpos com expressão positiva (n=19) ou negativa (n=19) para o marcador C4d, juntamente com levantamento de dados clínicos e laboratoriais pertinentes ao estudo. Foram realizadas reações imuno-histoquímicas, para os marcadores CD56, CD57, CD16, CD68, CD3, CD8 e CD4 com ênfase para os marcadores CD56 e CD16. Foi feita análise das células positivas em toda a cortical da biópsia nos compartimento intersticial, glomerular e vascular. Testes estatísticos foram aplicados conforme os pressupostos definidos no objetivo da pesquisa. RESULTADOS: No compartimento intersticial, células CD56+ (P = 0,004) e CD57+ (P < 0,001) foram expressas em maior quantidade em biópsias negativas para dosagem sérica de anticorpos específicos anti-doador (DSA) com diagnóstico de rejeição aguda mediada por células T. CD56 intersticial foi associado estatisticamente com presença de glomerulite (g >= 1) (P = 0,02) e ausência / leve capilarite peritubular (ptc <= 1) (P = 0,003). Células intersticiais positivas para o marcador CD56 com média superior a 0,56 céls/mm2 tiveram uma pior sobrevida do enxerto renal (P = 0,028). Biópsias com contagem inferior ou igual a 0,56 cél/mm2 tiveram associação estatisticamente significante para ausência ou leve capilarite peritubular (P = 0,012) e com contagem superior a 0,56 céls/mm2, foram associadas à presença de glomerulite (P = 0,002). Foi observado maior número de células positivas para o marcador CD16 no compartimento glomerular em biópsias positivas para dosagem sérica de DSA com diagnóstico de rejeição aguda mediada por anticorpos (P = 0,03) e em biópsias com presença de glomerulite (P = 0,009). Presença de maior número de células CD16+ no compartimento intersticial associou-se com capilarite peritubular (P = 0,0001). CONCLUSÕES: Maior expressão de células CD56 positivas no compartimento intersticial das biópsias foi significantemente associada com escores relacionados à lesão na microcirculação, especialmente glomerulite, com rejeição aguda mediada por células T e pior sobrevida do enxerto renal. Células CD16 positivas, no compartimento glomerular foram associadas com rejeição aguda mediada por anticorpos e glomerulite. As variações na expressão dos marcadores de células NK nos diferentes compartimentos da biópsia renal podem sugerir presença de envolvimento das células NK em diferentes vias do sistema imune nas rejeições agudas de aloenxertos renais / INTRODUCTION: The aim of this study was to investigate the immunohistochemical profile of markers related to NK cells from renal allograft biopsies with morphological diagnosis of acute rejection (T-cells or antibodies mediated rejection) and to study associations of those markers with types of rejection, microcirculation injury morphological parameters and graft survival. METHODOLOGY: Historical retrospective study that reviewed 74 biopsies performed between January 2009 and December 2012 in patients with acute T-cell-mediated rejection (n=36) and acute antibody-mediated rejection with (n=19) or without evident C4d deposition (n=19). The study was performed with relevant clinical and laboratory data. Immunohistochemical reactions were performed for CD56, CD57, CD16, CD68, CD3, CD8 and CD4 markers with highlights for CD56 and CD16. Counting of positive cells throughout cortical biopsy was performed in glomerular, interstitial and vascular compartments. Statistical tests were applied according to assumptions set out the goal of the study.RESULTS: DSA-negative biopsies-from patients with acute T-cell mediated rejection (aTCMR) had an increased expression of CD56+ and CD57+ cells (P = 0.004 and P < 0.001) in the interstitial compartment in comparison with donor-specific antibodies ( DSA)-positive biopsies from patients acute antibody-mediated rejection with and without C4d deposition. Interstitial CD56+ cells had an increased expression for presence of glomerulitis (g >= 1) (P = 0.02) and peritubular capillaritis (ptc >= 2) (P = 0.003). Interstitial CD56 + cells with mean superior to 0.56cells/mm2 had worse allograft survival (P = 0.028). CD56+ cells in the interstitial compartment with mean inferior or equal to 0.56cells/mm2 associated with absence or mild peritubular capillaritis (P = 0.012) and mean superior to 0.56cells/mm2 was associated with presence of glomerulitis (P = 0.002). CD16+ cells was increased in the glomerular compartment in DSA-positive biopsies (P = 0.03) and in the presence of glomerulitis (P = 0.009). Interstitial CD16+ cells associated with peritubular capillaritis (P = 0.0001).CONCLUSION: CD56+ cell infiltrates in the interstitial compartment were significantly associated with microcirculation injury scores, especially glomerulitis, acute T-cell mediated rejection and clinical outcomes. CD16+ cell infiltrates in glomerular compartment was associated with acute antibody-mediated rejection and glomerulitis. Our findings showed variations in expression of NK cells markers in renal biopsy different compartments which might suggest the involvement of NK cells in different immune system pathways in acute renal allograft rejection
17

Pour une philosophie clinique des greffes de mains et de visage : histoire, épistémologie, éthique / Towards a clinical philosophy of hand and face allografts : history, epistemology, ethics

Dumont, Martin 02 December 2017 (has links)
Ce travail s’efforce d’élaborer une philosophie clinique des greffes, particulièrement des greffes de mains et de visage ; c’est-à-dire une philosophie qui repart toujours de l’expérience du soin et des patients. L’histoire de la constitution des greffes comme soin efficace, du début du vingtième siècle aux années 1960, y est examinée : elle permet de percevoir les obstacles inattendus qu’il a fallu apprendre à surmonter, et combien ces procédures reposent sur des conditions précises et contraignantes. Cette épistémologie critique permet ensuite d’aborder les questions éthiques soulevées par les greffes de tissus composites. Celles-ci ont suscité d’importants débats, auxquels la clinique a en partie apporté des réponses. Mais des questions éthiques subsistent, qui sont abordées en décrivant les conditions délicates du choix de la procédure et en interrogeant les normes qui légitiment de recourir à ce soin risqué pour le traitement de handicaps graves. / This work aims at building a clinical philosophy of transplantations, especially in regards to hand and face allografts; this means a philosophy rooted in the experience of care and that of the patients. The history of the establishment of transplantation as an efficient procedure, from the beginning of the twentieth century to the 1960s, is examined: it helps understand the unexpected challenges that had to be met, and how these procedures are subject to precise and restrictive conditions. This critical epistemology then allows to approach the ethical questions raised by composite tissue allografts. These procedures have given birth to intense debate, to which the clinic has already partially brought answers. But other ethical problems remain, which are considered by describing the delicate conditions for choosing the procedure and by interrogating the norms legitimating this risky procedure as a cure for severe handicaps.
18

Obliteração de cavidades mastoideas com aloenxerto ósseo particulado congelado em cirurgias revisionais de otite média crônica colesteatomatosa / Mastoid cavity obliteration with particulated frozen allograft bone in revisional surgery for chronic otitis media with cholesteatoma

Fonseca, Anna Carolina de Oliveira 04 May 2016 (has links)
Objetivo: Avaliar o controle da supuração de cavidades mastoideas após cirurgia revisional e obliteração de mastoide com aloenxerto ósseo particulado congelado (AOPC). Desenho do estudo: Exploratório, prospectivo, tipo série de casos. Pacientes: Dez adultos selecionados entre pacientes já submetidos à cirurgia de mastoidectomia cavidade aberta ou fechada para tratamento de otite média crônica colesteatomatosa e que tinham indicação de cirurgia revisional. Intervenção: Revisão de mastoidectomia e obliteração da cavidade com AOPC, material de preenchimento de baixo custo obtido de um banco de tecidos. Desfecho(s): Desfecho primário: controle da supuração. Desfechos secundários incluem: integração do AOPC na cavidade mastoidea, presença de colesteatoma residual ou recorrente, resultados audiológicos, complicações pós-operatórias, tais como infecção e extrusão do enxerto, e qualidade de vida após o procedimento medida com a escala de resultados de Glasgow (ERG). Resultados: O tempo médio de seguimento foi de 28 meses. Sete pacientes apresentaram o ouvido seco, em média, 8 semanas após a cirurgia. Três pacientes desenvolveram exposição do enxerto ósseo seguido de infecção e extrusão do material de preenchimento. A densidade média do enxerto ósseo no local da obliteração foi de 755.35 unidades Hounsfield medida na tomografia realizada após um tempo médio pós-operatório de 31 meses. A porcentagem do volume mastoideo obliterado foi de 75 a 100% em 6 casos e de 50 a 75% em 1 caso. Nos 7 pacientes, houve um aumento na densidade óssea durante o período de seguimento. Um paciente apresentou colesteatoma epitimpânico recorrente (0,5cm) identificado na ressonância magnética 1 ano após a cirurgia, embora este não estivesse na área de obliteração. A audição foi preservada em 80% dos pacientes 12 meses após o procedimento. A qualidade de vida melhorou em todos os pacientes, com média do escore ERG de 52, em escala que varia de -100 a +100. Conclusões: Este estudo demonstrou que o AOPC pode ser usado como material de preenchimento na obliteração mastoidea para se obter um ouvido seco, apresentando boa integração na mastoide e manutenção da densidade óssea / Objective: Assess the control of suppuration after revision surgery with mastoid obliteration for chronic otitis media (COM) with cholesteatoma using particulated frozen allograft bone (PFAB). Study Design: Exploratory, prospective, case series. Patients: Ten adults were selected from among patients who had undergone canal wall down or canal wall up mastoidectomy for COM with cholesteatoma, and had an indication for revision surgery. Intervention(s): Revision mastoidectomy with obliteration of the open cavity was performed with PFAB, a low-cost filler material obtained from a tissue bank. Main Outcome Measure(s): The main outcome measure was the control of suppuration. Secondary outcome measures included PFAB integration in the mastoid cavity, presence of recurrent or residual cholesteatoma, hearing outcomes, postoperative complications as infection and bone graft extrusion and quality of life after the procedure using the Glasgow benefit inventory (GBI) survey. Results: Mean follow-up was 28 months. Seven patients achieved a dry ear at a mean of 8 weeks postoperatively. Three patients developed bone graft exposure followed by infection and extrusion of the filler material. Mean bone density was 755.35 Hounsfield units at the obliteration site measured at computed tomography performed after a mean of 31 months postoperatively. Percentage of mastoid volume obliterated was between 75% and 100% in 6 cases and between 50% and 75% in 1 case. In all 7 patients, there was an increase in bone density postoperatively. One patient presented with recurrent epitympanic cholesteatoma (0.5 cm) at 1 year postoperatively, but it was not in the obliteration area. At 12 months postoperatively, 80% of patients had preserved hearing. All patients had an improvement of quality of life after mastoid obliteration, the average score on the GBI was 52 in a scale from -100 to +100. Conclusions: This study demonstrated that PFAB may be used to achieve a dry mastoid cavity with good bone graft osteointegration and density maintenance
19

Πειραματική συγκριτική μελέτη αναγγείων μοσχευμάτων για την πλήρωση οστικών ελλειμάτων / Comparative experimental study of nonvascular bone grafts for bone defect filling

Αθανασίου, Βασίλειος 31 March 2010 (has links)
Σκοπός αυτής της πειραματικής μελέτης είναι ο έλεγχος βιολογικής συμπεριφοράς διαφόρων τύπων μοσχευμάτων που σήμερα χρησιμοποιούνται ευρέως ως υποκατάστατα οστοών. Υλικό–Μέθοδος: Στην παρούσα μελέτη χρησιμοποιήθηκαν 90 κουνέλια Νέας Ζηλανδίας, ηλικία 3.5 μηνών και βάρους 4(0.25)kg, τα οποία χωρίσθηκαν σε 6 ομάδες, η κάθε μία εκ των οποίων περιελάμβανε 15 κουνέλια. Υπό γενική αναισθησία, με ενδομυϊκή χορήγηση κεταμίνης 35mg/kg και ξυλαζίνης 5mg/kg, δημιουργήθηκε, με πλάγια χειρουργική προσπέλαση, μια οπή με φρέζα διαμέτρου 4.5mm και βάθους 8mm, στους μηριαίους κονδύλους των 2 οπισθίων άκρων του κάθε κουνελιού (σύνολο 180 οπές). Στις οπές αυτές τοποθετήθηκαν τα ακόλουθα μοσχεύματα: Ομάδα Ι-αυτομόσχευμα, Ομάδα ΙΙ-αλλομόσχευμα (Grafton®), Ομάδα ΙΙΙ-ξενομόσχευμα (Lubboc®), Ομάδα ΙV-συνθετικό υποκατάστατο οστικών μοσχευμάτων (Ceraform®), Ομάδα V- συνθετικό υποκατάστατο οστικών μοσχευμάτων (Οsteoset®), Ομάδα VI-χωρίς μόσχευμα. Μετά την τοποθέτηση των μοσχευμάτων, τα κουνέλια θυσιάστηκαν με ενδοφλέβια νατριούχο θειοπεντάλη 5ml (pentothal) 10%, σε 1, 3 και 6 μήνες όπου έγινε λήψη δειγμάτων (το κάτω τριτημόριο του μηριαίου) για ιστολογική μελέτη. Τα δείγματα αξιολογήθηκαν με μια ιστολογική κλίμακα βαθμολόγησης 15-point για να καθοριστεί η ποιότητα της πώρωσης, η παρουσία οστικού ελλείμματος, η νέοαγγειογένεση και η αντιδραστική παρουσία κυττάρων φλεγμονής, καθώς και ο βαθμός ενσωμάτωσης και ανακατασκευής του πώρου. Αποτελέσματα: Σύμφωνα με την ιστολογική κλίμακα το αυτομόσχευμα έδειξε τα καλύτερα αποτελέσματα σε όλες τις χρονικές στιγμές. Όλοι οι άλλοι τύποι μοσχεύματος έδειξαν σημαντικά κατώτερα αποτελέσματα σε σχέση με το αυτόλογο μόσχευμα (p≤0.05). Το Lubboc είχε σημαντικά καλύτερα αποτελέσματα σε σχέση με τα άλλα τρία μοσχεύματα (Grafton, Ceraform και Osteoset). Το Ceraform είχε τα κατώτερα αποτελέσματα σε όλες τις κατιγορίες Συμπεράσματα: Το αυτόλογο μόσχευμα παραμένει το πρότυπο αναφοράς “gold standard” των μοσχευμάτων, επιδεικνύοντας εξαιρετικές ικανότητες ενσωμάτωσης. Το βόειο ξενομόσχευμα (Lubboc®) συνέβαλλε στη σύνθεση του πεταλιώδους οστού πιο αποτελεσματικά από το αλλομόσχευμα (Grafton®). Τα υποκατάστατα οστών (Ceraform® και Οsteoset®) ήταν κατώτερα από τα αλλομοσχεύματα και τα ξενομοσχεύματα / Background: Different types of bone-graft substitutes have been developed and are on the market worldwide to eliminate the drawbacks of autogenous grafting. This experimental animal study was undertaken to evaluate the different histological properties of various bone graft substitutes utilized in this hospital. Material/Methods: Ninety New Zealand white rabbits were divided into six groups of 15 animals. Under general anesthesia, a 4.5 mm-wide hole was drilled into both the lateral femoral condyles of each rabbit, for a total of 180 condyles for analysis. The bone defects were filled with various grafts, these being 1) autograft, 2) DBM crunch allograft (Grafton(R)), 3) bovine cancellous bone xenograft (Lubboc(R)), 4) calcium phosphate hydroxyapatite substitute (Ceraform(R)), 5) calcium sulfate substitute (Osteoset(R)), and 6) no filling (control). The animals were sacrificed at 1, 3, and 6 months after implantation and tissue samples from the implanted areas were processed for histological evaluation. A histological grading scale was designed to determine the different histological parameters of bone healing. Results: The highest histological grades were achieved with the use of cancellous bone autograft. Bovine xenograft (Lubboc) was the second best in the histological scale grading. The other substitutes (Grafton, Ceraform, Osteoset) had similar scores but were inferior to both allograft and xenograft. Conclusions: Bovine xenograft showed better biological response than the other bone graft substitutes; however, more clinical studies are necessary to determine its overall effectiveness.
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Obliteração de cavidades mastoideas com aloenxerto ósseo particulado congelado em cirurgias revisionais de otite média crônica colesteatomatosa / Mastoid cavity obliteration with particulated frozen allograft bone in revisional surgery for chronic otitis media with cholesteatoma

Anna Carolina de Oliveira Fonseca 04 May 2016 (has links)
Objetivo: Avaliar o controle da supuração de cavidades mastoideas após cirurgia revisional e obliteração de mastoide com aloenxerto ósseo particulado congelado (AOPC). Desenho do estudo: Exploratório, prospectivo, tipo série de casos. Pacientes: Dez adultos selecionados entre pacientes já submetidos à cirurgia de mastoidectomia cavidade aberta ou fechada para tratamento de otite média crônica colesteatomatosa e que tinham indicação de cirurgia revisional. Intervenção: Revisão de mastoidectomia e obliteração da cavidade com AOPC, material de preenchimento de baixo custo obtido de um banco de tecidos. Desfecho(s): Desfecho primário: controle da supuração. Desfechos secundários incluem: integração do AOPC na cavidade mastoidea, presença de colesteatoma residual ou recorrente, resultados audiológicos, complicações pós-operatórias, tais como infecção e extrusão do enxerto, e qualidade de vida após o procedimento medida com a escala de resultados de Glasgow (ERG). Resultados: O tempo médio de seguimento foi de 28 meses. Sete pacientes apresentaram o ouvido seco, em média, 8 semanas após a cirurgia. Três pacientes desenvolveram exposição do enxerto ósseo seguido de infecção e extrusão do material de preenchimento. A densidade média do enxerto ósseo no local da obliteração foi de 755.35 unidades Hounsfield medida na tomografia realizada após um tempo médio pós-operatório de 31 meses. A porcentagem do volume mastoideo obliterado foi de 75 a 100% em 6 casos e de 50 a 75% em 1 caso. Nos 7 pacientes, houve um aumento na densidade óssea durante o período de seguimento. Um paciente apresentou colesteatoma epitimpânico recorrente (0,5cm) identificado na ressonância magnética 1 ano após a cirurgia, embora este não estivesse na área de obliteração. A audição foi preservada em 80% dos pacientes 12 meses após o procedimento. A qualidade de vida melhorou em todos os pacientes, com média do escore ERG de 52, em escala que varia de -100 a +100. Conclusões: Este estudo demonstrou que o AOPC pode ser usado como material de preenchimento na obliteração mastoidea para se obter um ouvido seco, apresentando boa integração na mastoide e manutenção da densidade óssea / Objective: Assess the control of suppuration after revision surgery with mastoid obliteration for chronic otitis media (COM) with cholesteatoma using particulated frozen allograft bone (PFAB). Study Design: Exploratory, prospective, case series. Patients: Ten adults were selected from among patients who had undergone canal wall down or canal wall up mastoidectomy for COM with cholesteatoma, and had an indication for revision surgery. Intervention(s): Revision mastoidectomy with obliteration of the open cavity was performed with PFAB, a low-cost filler material obtained from a tissue bank. Main Outcome Measure(s): The main outcome measure was the control of suppuration. Secondary outcome measures included PFAB integration in the mastoid cavity, presence of recurrent or residual cholesteatoma, hearing outcomes, postoperative complications as infection and bone graft extrusion and quality of life after the procedure using the Glasgow benefit inventory (GBI) survey. Results: Mean follow-up was 28 months. Seven patients achieved a dry ear at a mean of 8 weeks postoperatively. Three patients developed bone graft exposure followed by infection and extrusion of the filler material. Mean bone density was 755.35 Hounsfield units at the obliteration site measured at computed tomography performed after a mean of 31 months postoperatively. Percentage of mastoid volume obliterated was between 75% and 100% in 6 cases and between 50% and 75% in 1 case. In all 7 patients, there was an increase in bone density postoperatively. One patient presented with recurrent epitympanic cholesteatoma (0.5 cm) at 1 year postoperatively, but it was not in the obliteration area. At 12 months postoperatively, 80% of patients had preserved hearing. All patients had an improvement of quality of life after mastoid obliteration, the average score on the GBI was 52 in a scale from -100 to +100. Conclusions: This study demonstrated that PFAB may be used to achieve a dry mastoid cavity with good bone graft osteointegration and density maintenance

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