abstract: Treatment of cerebral aneurysms using non-invasive methods has existed for decades. Since the advent of modern endovascular techniques, advancements to embolic materials have largely focused on improving platinum coil technology. However, the recent development of Onyx®, a liquid-delivery precipitating polymer system, has opened the door for a new class of embolic materials--liquid-fill systems. These liquid-fill materials have the potential to provide better treatment outcomes than platinum coils. Initial clinical use of Onyx has proven promising, but not without substantial drawbacks, such as co-delivery of angiotoxic compounds and an extremely technical delivery procedure. This work focuses on formulation, characterization and testing of a novel liquid-to-solid gelling polymer system, based on poly(propylene glycol) diacrylate (PPODA) and pentaerythritol tetrakis(3-mercaptopropionate) (QT). The PPODA-QT system bypasses difficulties associated with Onyx embolization, yet still maintains non-invasive liquid delivery--exhibiting the properties of an ideal embolic material for cerebral aneurysm embolization. To allow for material visibility during clinical delivery, an embolic material must be radio-opaque. The PPODA-QT system was formulated with commercially available contrast agents and the gelling kinetics were studied, as a complete understanding of the gelling process is vital for clinical use. These PPODA-QT formulations underwent in vitro characterization of material properties including cytotoxicity, swelling, and degradation behaviors. Formulation and characterization tests led to an optimized PPODA-QT formulation that was used in subsequent in vivo testing. PPODA-QT formulated with the liquid contrast agent ConrayTM was used in the first in vivo studies. These studies employed a swine aneurysm model to assess initial biocompatibility and test different delivery strategies of PPODA-QT. Results showed good biocompatibility and a suitable delivery strategy, providing justification for further in vivo testing. PPODA-QT was then used in a small scale pilot study to gauge long-term effectiveness of the material in a clinically-relevant aneurysm model. Results from the pilot study showed that PPODA-QT has the capability to provide successful, long-term treatment of model aneurysms as well as facilitate aneurysm healing. / Dissertation/Thesis / Ph.D. Bioengineering 2011

Objetivo: Desenvolver um modelo experimental de aneurisma cerebral em artéria de suínos. Secundariamente, avaliar o processo de organização do trombo e de formação de tecido fibrocelular dentro do aneurisma com o tratamento endovascular utilizando molas revestidas (Matrix) comparadas às sem revestimento (GDC). Materiais e Métodos: Em 10 suínos sadios, com peso variando entre 16 e 20 kg, sendo 6 machos e 4 fêmeas, foi realizada a cirurgia de formação de aneurisma nas carótidas bilateralmente, através de arteriotomia e anastomose término-lateral com segmento de veia jugular. O diâmetro médio dos aneurismas era de 3 mm (variação de 2 a 4mm). Procedia-se então ao tratamento endovascular dos aneurismas divididos do seguinte modo: grupo I, embolização do aneurisma da carótida esquerda com mola de platina (GDC); grupo II, embolização do aneurisma da carótida direita com mola de platina revestida com copolímero - PGLA 90/10 (Matrix). Após 14 dias, eram retiradas as lesões e analisadas microscopicamente, comparando-se a formação de trombo recente ou trombo organizado no interior de cada aneurisma. Para isso, foi criada uma escala de caracterização das fases do processo de trombose (Escores de 1 a 4). O Escore 1 era definido como a presença de trombo inicial ou recente; o Escore 2 era categorizado como a presença de leucócitos em diferenciação contendo fibrina e absorção das hemácias e plaquetas, porém intercalados com zonas contendo trombo recente. No Escore 3, observavase a presença de leucócitos em diferenciação contendo fibrina e no Escore 4, a presença de tecido fibrocelular contendo fibras de colágeno. A análise estatística foi realizada de modo pareado, através do Teste de Wilcoxon, sendo os dados processados no programa SPSS 12.0. O nível de significância mínimo adotado foi de 5%. Resultados: Um animal (macho) foi excluído do estudo devido à formação de abscesso cervical, restando, portanto, 9 animais (18 aneurismas para avaliação). Na análise do processo de organização do trombo, utilizou-se a graduação por escores, obtendo-se no grupo I, 88,8% de casos de trombo recente (Escore 1) e 11,1% de casos de trombo em organização ainda contendo coágulo (Escore 2). No grupo II, obteve-se 11,1% de casos com escore 1 , 11,1% com escore 2, 55,5% de casos de trombo organizado com tecido fibrocelular frouxo (Escore 3) e 22,2% de casos de tecido fibrocelular denso contendo colágeno (Escore 4). Houve diferença estatística a favor do grupo II, por meio do Teste de Wilcoxon (p=0,008). Conclusão: O modelo experimental de aneurisma de pequenas dimensões utilizado neste estudo foi adequado e permitiu a realização do tratamento endovascular testando dois tipos de molas. Por meio da análise histológica baseada em escala criada para avaliar a organização do trombo, pôde-se verificar diferença significativa a favor das molas com revestimento de copolímero. / Background and Objectives: To develop an experimental model in a pig that could be used for analysis of patency of cerebral aneurysms is the goal of this study. Adictionaly, it aims to evaluate the degree of thrombosis after embolization with two types of coils: copolymer-coated coils (Matrix) and uncoated platinum coils (GDC). Method: In a total of 10 Large-White pigs, small aneurysms (with a mean diameter of 3 mm) were created in both carotid arteries (6 males and 4 females) weighing 16 to 20 kg (mean: 18 kg). Embolization was performed with GDC platinum coils on the left side and with a coil coated with Matrix polymer on the right side. After 14 days, angiography was performed to confirm exclusion of the aneurysm. Before euthanasia with a lethal dose of potassium chloride, the carotid artery was removed in one piece, including the aneurysm. The specimens were cut into sections, including the mid portion of the aneurysm and the artery above and below the aneurysm, and stained with hematoxylin- eosin for histological analysis. A graduated scale with progressive scores ranging from 1 to 4 was used to evaluate the organization of the thrombus. Score 1 indicated clusters of platelets, white blood cells, and red blood cells; Score 2 showed the presence of differentiating white blood cells containing fibrin and absorption of red blood cells and platelets, interspersed with zones containing a recent thrombus; Score 3 corresponded to the presence of differentiating white blood cells containing fibrin, which characterized a loose fibrocellular tissue; and Score 4 indicated the presence of fibrocellular tissue containing collagen fibers, which characterized an incipient dense fibrocellular tissue The data were described as frequency and percentage using the Wilcoxon test for findings involving thrombosis scores. The data were analyzed using the SPSS 12.0 software, and the minimum significance level was set at 5%. Results: One animal (male) was excluded from the study due to abscess formation near the anastomosis. Therefore, 9 animals (18 aneurysms) were assessed. A score was used for analyzing the organization of the thrombus. In group I, 88.8% had score 1, 11.1% score 2, but no cases showed scores 3 and 4. In group II, 11.1% had score 1, 11.1% score 2, 55.5% score 3, and 22.2% score 4. The Wilcoxon test was applied, revealing a significant difference (p=0.008) between the scores for group I and group II in the course of 14 days. Conclusion: The experimental aneurysm developed in this study was suitable for assessing the patency of small aneurysms (measuring, on average, 3 mm) after coil embolization. The organization of the intra-aneurysmal thrombus after 14 days was verified using the progressive score, which indicated a significant difference between the group treated with the Matrix coil and that treated with GDC.

Introduction: The reason for the inability of performing the liver resection for colorectal carcinoma metastasis is usually insufficient remnant liver parenchyma after liver resection (future liver remnant volume - FLRV). The current standard method of increasing FLRV is the embolization of the branch of portal vein (portal vein embolization - PVE) on the side of the tumor, and then suspended after hypertrophy of the non-embolised lobe liver resection. Unfortunately, there are some patients who do not increase liver volume despite perfectly executed PVE. Besides that, FLRV occurs during the time necessary for hypertrophy progression of metastatic disease. Therefore, we are trying to find the appropriate way to encourage the growth of remaining liver parenchyma and accelerate hypertrophy of the contralateral liver lobe. From our previous experience (IGA MZ NS 10240), it is possible to be optimistic that there hope is the way of hematopoietic progenitor cells (HPC - adult stem cells) after previous PVE to non-embolised branches of the portal vein. These cells do not only accelerate liver regeneration, but are also able to improve its function (function of the liver) which is especially important for patients after neoadjuvant chemotherapy (steatohepatitis or steatofibrosis), and for patients with...

Objetivo: Desenvolver um modelo experimental de aneurisma cerebral em artéria de suínos. Secundariamente, avaliar o processo de organização do trombo e de formação de tecido fibrocelular dentro do aneurisma com o tratamento endovascular utilizando molas revestidas (Matrix) comparadas às sem revestimento (GDC). Materiais e Métodos: Em 10 suínos sadios, com peso variando entre 16 e 20 kg, sendo 6 machos e 4 fêmeas, foi realizada a cirurgia de formação de aneurisma nas carótidas bilateralmente, através de arteriotomia e anastomose término-lateral com segmento de veia jugular. O diâmetro médio dos aneurismas era de 3 mm (variação de 2 a 4mm). Procedia-se então ao tratamento endovascular dos aneurismas divididos do seguinte modo: grupo I, embolização do aneurisma da carótida esquerda com mola de platina (GDC); grupo II, embolização do aneurisma da carótida direita com mola de platina revestida com copolímero - PGLA 90/10 (Matrix). Após 14 dias, eram retiradas as lesões e analisadas microscopicamente, comparando-se a formação de trombo recente ou trombo organizado no interior de cada aneurisma. Para isso, foi criada uma escala de caracterização das fases do processo de trombose (Escores de 1 a 4). O Escore 1 era definido como a presença de trombo inicial ou recente; o Escore 2 era categorizado como a presença de leucócitos em diferenciação contendo fibrina e absorção das hemácias e plaquetas, porém intercalados com zonas contendo trombo recente. No Escore 3, observavase a presença de leucócitos em diferenciação contendo fibrina e no Escore 4, a presença de tecido fibrocelular contendo fibras de colágeno. A análise estatística foi realizada de modo pareado, através do Teste de Wilcoxon, sendo os dados processados no programa SPSS 12.0. O nível de significância mínimo adotado foi de 5%. Resultados: Um animal (macho) foi excluído do estudo devido à formação de abscesso cervical, restando, portanto, 9 animais (18 aneurismas para avaliação). Na análise do processo de organização do trombo, utilizou-se a graduação por escores, obtendo-se no grupo I, 88,8% de casos de trombo recente (Escore 1) e 11,1% de casos de trombo em organização ainda contendo coágulo (Escore 2). No grupo II, obteve-se 11,1% de casos com escore 1 , 11,1% com escore 2, 55,5% de casos de trombo organizado com tecido fibrocelular frouxo (Escore 3) e 22,2% de casos de tecido fibrocelular denso contendo colágeno (Escore 4). Houve diferença estatística a favor do grupo II, por meio do Teste de Wilcoxon (p=0,008). Conclusão: O modelo experimental de aneurisma de pequenas dimensões utilizado neste estudo foi adequado e permitiu a realização do tratamento endovascular testando dois tipos de molas. Por meio da análise histológica baseada em escala criada para avaliar a organização do trombo, pôde-se verificar diferença significativa a favor das molas com revestimento de copolímero. / Background and Objectives: To develop an experimental model in a pig that could be used for analysis of patency of cerebral aneurysms is the goal of this study. Adictionaly, it aims to evaluate the degree of thrombosis after embolization with two types of coils: copolymer-coated coils (Matrix) and uncoated platinum coils (GDC). Method: In a total of 10 Large-White pigs, small aneurysms (with a mean diameter of 3 mm) were created in both carotid arteries (6 males and 4 females) weighing 16 to 20 kg (mean: 18 kg). Embolization was performed with GDC platinum coils on the left side and with a coil coated with Matrix polymer on the right side. After 14 days, angiography was performed to confirm exclusion of the aneurysm. Before euthanasia with a lethal dose of potassium chloride, the carotid artery was removed in one piece, including the aneurysm. The specimens were cut into sections, including the mid portion of the aneurysm and the artery above and below the aneurysm, and stained with hematoxylin- eosin for histological analysis. A graduated scale with progressive scores ranging from 1 to 4 was used to evaluate the organization of the thrombus. Score 1 indicated clusters of platelets, white blood cells, and red blood cells; Score 2 showed the presence of differentiating white blood cells containing fibrin and absorption of red blood cells and platelets, interspersed with zones containing a recent thrombus; Score 3 corresponded to the presence of differentiating white blood cells containing fibrin, which characterized a loose fibrocellular tissue; and Score 4 indicated the presence of fibrocellular tissue containing collagen fibers, which characterized an incipient dense fibrocellular tissue The data were described as frequency and percentage using the Wilcoxon test for findings involving thrombosis scores. The data were analyzed using the SPSS 12.0 software, and the minimum significance level was set at 5%. Results: One animal (male) was excluded from the study due to abscess formation near the anastomosis. Therefore, 9 animals (18 aneurysms) were assessed. A score was used for analyzing the organization of the thrombus. In group I, 88.8% had score 1, 11.1% score 2, but no cases showed scores 3 and 4. In group II, 11.1% had score 1, 11.1% score 2, 55.5% score 3, and 22.2% score 4. The Wilcoxon test was applied, revealing a significant difference (p=0.008) between the scores for group I and group II in the course of 14 days. Conclusion: The experimental aneurysm developed in this study was suitable for assessing the patency of small aneurysms (measuring, on average, 3 mm) after coil embolization. The organization of the intra-aneurysmal thrombus after 14 days was verified using the progressive score, which indicated a significant difference between the group treated with the Matrix coil and that treated with GDC.

Made available in DSpace on 2014-06-11T19:22:54Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-07-29Bitstream added on 2014-06-13T20:10:04Z : No. of bitstreams: 1 basso_gg_me_sjrp_parcial.pdf: 127718 bytes, checksum: 3bfde1c4f9ff597bf78cc0fd338d9fe8 (MD5) Bitstreams deleted on 2015-08-28T16:08:53Z: basso_gg_me_sjrp_parcial.pdf,. Added 1 bitstream(s) on 2015-08-28T16:09:58Z : No. of bitstreams: 1 000670722.pdf: 6039395 bytes, checksum: a8326c9658e562fa0ebe828de242a31a (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Financiadora de Estudos e Projetos (FINEP) / Partículas poliméricas com tamanho e morfologia controlados e propriedades físico-químicas adequadas são amplamente utilizadas em aplicações médicas, como na embolização, uma técnica cirúrgica utilizada para tratar malformações arteriovenosas (MAVs), conter hemorragias, tratar localmente tumores hipervascularizados (THVs) e outras doenças vasculares. Este procedimento é realizado com materiais de diferentes formas e composições, sendo as partículas de poli(álcool vinílico) (PVA) freqüentemente utilizadas por apresentarem um alto grau de desempenho. Elas estão disponíveis no mercado nas morfologias esférica e não-esférica, sendo que as esféricas apresentam uma maior eficácia no tratamento. O presente trabalho objetivou desenvolver e aprimorar partículas esféricas de PVA e poli(acetato vinílico) (PVAc) para serem utilizadas em embolização. Suas sínteses foram realizadas em duas etapas: a polimerização em suspensão do monômero acetato vinílico (VAc) em PVAc e a saponificação do polímero PVAc em PVA, com variações na velocidade de agitação e na concentração da solução de hidróxido de sódio (NaOH), na etapa da saponificação. As partículas foram caracterizadas por microscopia eletrônica de varredura (MEV), difração de raios-X (DRX), calorimetria diferencial de varredura (DSC) e ressonância magnética nuclear de 13 C - cross polarization / magic angle spinning (13 C RMN CP/MAS). Foram analisadas a distribuição de tamanhos, a dimensão fractal, a determinação da biocarga, que determinou os parâmetros de esterilização por radiação gama, e a citotoxicidade, pelo teste de “Reatividade Biológica in vitro”. Os resultados indicaram que a morfologia esférica foi obtida durante a primeira etapa da síntese e que essa morfologia não foi afetada pelo segundo processo. A velocidade de agitação e a concentração de NaOH influenciaram... / Polymeric particles with controlled size and morphology and appropriated physicochemical properties are widely used in medical applications, such as embolization, a surgical technique used to treat arteriovenous malformations (AVMs), stop bleedings, treat locally hypervascular tumors (HVTs) and other vascular diseases. This procedure is performed with materials of different shapes and compositions, and the poly(vinyl alcohol) (PVA) particles are often used for presenting a high degree of performance. They are commercially available in spherical and non-spherical morphologies, and the spherical particles have a greater efficacy in the treatment. This study aimed to develop and improve spherical PVA and poly(vinyl acetate) (PVAc) particles for use in embolization. Their syntheses were performed in two stages: the suspension polymerization of vinyl acetate (VAc) monomer in PVAc and the saponification of PVAc polymer in PVA, with variations in the stirring speed and the concentration of sodium hydroxide (NaOH) solution, at the saponification step. The particles were characterized by scanning electronic microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and 13 C nuclear magnetic resonance - cross polarization / magic angle spinning (13 C NMR CP/MAS). We analyzed the size distribution, the fractal dimension, the determining of the bioburden, which determined the parameters of sterilization by gamma irradiation, and the cytotoxicity, by the “Biological Reactivity in vitro”. The results indicated that the spherical morphology was obtained during the first stage of the synthesis and that this morphology was not affected by the second process. The stirring speed and the NaOH concentration influenced the size of the particles. The commercial particles have a fractal dimension greater than the synthesized particles... (Complete abstract click electronic access below)

Resumo: Partículas poliméricas com tamanho e morfologia controlados e propriedades físico-químicas adequadas são amplamente utilizadas em aplicações médicas, como na embolização, uma técnica cirúrgica utilizada para tratar malformações arteriovenosas (MAVs), conter hemorragias, tratar localmente tumores hipervascularizados (THVs) e outras doenças vasculares. Este procedimento é realizado com materiais de diferentes formas e composições, sendo as partículas de poli(álcool vinílico) (PVA) freqüentemente utilizadas por apresentarem um alto grau de desempenho. Elas estão disponíveis no mercado nas morfologias esférica e não-esférica, sendo que as esféricas apresentam uma maior eficácia no tratamento. O presente trabalho objetivou desenvolver e aprimorar partículas esféricas de PVA e poli(acetato vinílico) (PVAc) para serem utilizadas em embolização. Suas sínteses foram realizadas em duas etapas: a polimerização em suspensão do monômero acetato vinílico (VAc) em PVAc e a saponificação do polímero PVAc em PVA, com variações na velocidade de agitação e na concentração da solução de hidróxido de sódio (NaOH), na etapa da saponificação. As partículas foram caracterizadas por microscopia eletrônica de varredura (MEV), difração de raios-X (DRX), calorimetria diferencial de varredura (DSC) e ressonância magnética nuclear de 13 C - cross polarization / magic angle spinning (13 C RMN CP/MAS). Foram analisadas a distribuição de tamanhos, a dimensão fractal, a determinação da biocarga, que determinou os parâmetros de esterilização por radiação gama, e a citotoxicidade, pelo teste de "Reatividade Biológica in vitro". Os resultados indicaram que a morfologia esférica foi obtida durante a primeira etapa da síntese e que essa morfologia não foi afetada pelo segundo processo. A velocidade de agitação e a concentração de NaOH influenciaram... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Polymeric particles with controlled size and morphology and appropriated physicochemical properties are widely used in medical applications, such as embolization, a surgical technique used to treat arteriovenous malformations (AVMs), stop bleedings, treat locally hypervascular tumors (HVTs) and other vascular diseases. This procedure is performed with materials of different shapes and compositions, and the poly(vinyl alcohol) (PVA) particles are often used for presenting a high degree of performance. They are commercially available in spherical and non-spherical morphologies, and the spherical particles have a greater efficacy in the treatment. This study aimed to develop and improve spherical PVA and poly(vinyl acetate) (PVAc) particles for use in embolization. Their syntheses were performed in two stages: the suspension polymerization of vinyl acetate (VAc) monomer in PVAc and the saponification of PVAc polymer in PVA, with variations in the stirring speed and the concentration of sodium hydroxide (NaOH) solution, at the saponification step. The particles were characterized by scanning electronic microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and 13 C nuclear magnetic resonance - cross polarization / magic angle spinning (13 C NMR CP/MAS). We analyzed the size distribution, the fractal dimension, the determining of the bioburden, which determined the parameters of sterilization by gamma irradiation, and the cytotoxicity, by the "Biological Reactivity in vitro". The results indicated that the spherical morphology was obtained during the first stage of the synthesis and that this morphology was not affected by the second process. The stirring speed and the NaOH concentration influenced the size of the particles. The commercial particles have a fractal dimension greater than the synthesized particles... (Complete abstract click electronic access below) / Orientador: José Geraldo Nery / Coorientador: Ana Paula Marques de Lima Oliveira / Banca: Rosa Sayoko Kawasaki Oyama / Banca: Moacir Fernandes de Godoy / Mestre

Objetivo: Desenvolver um modelo experimental de aneurisma cerebral em artéria de suínos. Secundariamente, avaliar o processo de organização do trombo e de formação de tecido fibrocelular dentro do aneurisma com o tratamento endovascular utilizando molas revestidas (Matrix) comparadas às sem revestimento (GDC). Materiais e Métodos: Em 10 suínos sadios, com peso variando entre 16 e 20 kg, sendo 6 machos e 4 fêmeas, foi realizada a cirurgia de formação de aneurisma nas carótidas bilateralmente, através de arteriotomia e anastomose término-lateral com segmento de veia jugular. O diâmetro médio dos aneurismas era de 3 mm (variação de 2 a 4mm). Procedia-se então ao tratamento endovascular dos aneurismas divididos do seguinte modo: grupo I, embolização do aneurisma da carótida esquerda com mola de platina (GDC); grupo II, embolização do aneurisma da carótida direita com mola de platina revestida com copolímero - PGLA 90/10 (Matrix). Após 14 dias, eram retiradas as lesões e analisadas microscopicamente, comparando-se a formação de trombo recente ou trombo organizado no interior de cada aneurisma. Para isso, foi criada uma escala de caracterização das fases do processo de trombose (Escores de 1 a 4). O Escore 1 era definido como a presença de trombo inicial ou recente; o Escore 2 era categorizado como a presença de leucócitos em diferenciação contendo fibrina e absorção das hemácias e plaquetas, porém intercalados com zonas contendo trombo recente. No Escore 3, observavase a presença de leucócitos em diferenciação contendo fibrina e no Escore 4, a presença de tecido fibrocelular contendo fibras de colágeno. A análise estatística foi realizada de modo pareado, através do Teste de Wilcoxon, sendo os dados processados no programa SPSS 12.0. O nível de significância mínimo adotado foi de 5%. Resultados: Um animal (macho) foi excluído do estudo devido à formação de abscesso cervical, restando, portanto, 9 animais (18 aneurismas para avaliação). Na análise do processo de organização do trombo, utilizou-se a graduação por escores, obtendo-se no grupo I, 88,8% de casos de trombo recente (Escore 1) e 11,1% de casos de trombo em organização ainda contendo coágulo (Escore 2). No grupo II, obteve-se 11,1% de casos com escore 1 , 11,1% com escore 2, 55,5% de casos de trombo organizado com tecido fibrocelular frouxo (Escore 3) e 22,2% de casos de tecido fibrocelular denso contendo colágeno (Escore 4). Houve diferença estatística a favor do grupo II, por meio do Teste de Wilcoxon (p=0,008). Conclusão: O modelo experimental de aneurisma de pequenas dimensões utilizado neste estudo foi adequado e permitiu a realização do tratamento endovascular testando dois tipos de molas. Por meio da análise histológica baseada em escala criada para avaliar a organização do trombo, pôde-se verificar diferença significativa a favor das molas com revestimento de copolímero. / Background and Objectives: To develop an experimental model in a pig that could be used for analysis of patency of cerebral aneurysms is the goal of this study. Adictionaly, it aims to evaluate the degree of thrombosis after embolization with two types of coils: copolymer-coated coils (Matrix) and uncoated platinum coils (GDC). Method: In a total of 10 Large-White pigs, small aneurysms (with a mean diameter of 3 mm) were created in both carotid arteries (6 males and 4 females) weighing 16 to 20 kg (mean: 18 kg). Embolization was performed with GDC platinum coils on the left side and with a coil coated with Matrix polymer on the right side. After 14 days, angiography was performed to confirm exclusion of the aneurysm. Before euthanasia with a lethal dose of potassium chloride, the carotid artery was removed in one piece, including the aneurysm. The specimens were cut into sections, including the mid portion of the aneurysm and the artery above and below the aneurysm, and stained with hematoxylin- eosin for histological analysis. A graduated scale with progressive scores ranging from 1 to 4 was used to evaluate the organization of the thrombus. Score 1 indicated clusters of platelets, white blood cells, and red blood cells; Score 2 showed the presence of differentiating white blood cells containing fibrin and absorption of red blood cells and platelets, interspersed with zones containing a recent thrombus; Score 3 corresponded to the presence of differentiating white blood cells containing fibrin, which characterized a loose fibrocellular tissue; and Score 4 indicated the presence of fibrocellular tissue containing collagen fibers, which characterized an incipient dense fibrocellular tissue The data were described as frequency and percentage using the Wilcoxon test for findings involving thrombosis scores. The data were analyzed using the SPSS 12.0 software, and the minimum significance level was set at 5%. Results: One animal (male) was excluded from the study due to abscess formation near the anastomosis. Therefore, 9 animals (18 aneurysms) were assessed. A score was used for analyzing the organization of the thrombus. In group I, 88.8% had score 1, 11.1% score 2, but no cases showed scores 3 and 4. In group II, 11.1% had score 1, 11.1% score 2, 55.5% score 3, and 22.2% score 4. The Wilcoxon test was applied, revealing a significant difference (p=0.008) between the scores for group I and group II in the course of 14 days. Conclusion: The experimental aneurysm developed in this study was suitable for assessing the patency of small aneurysms (measuring, on average, 3 mm) after coil embolization. The organization of the intra-aneurysmal thrombus after 14 days was verified using the progressive score, which indicated a significant difference between the group treated with the Matrix coil and that treated with GDC.

Introdução: Acretismo placentário é condição pouco frequente na qual há aderência anormal do tecido trofoblástico à parede uterina. É uma causa importante de hemorragia puerperal, associada a altas taxas de morbimortalidade maternofetal, grande necessidade de transfusão de hemoconcentrados. Os tratamentos propostos variam desde conduta conservadora até a histerectomia pós-parto, associada ou não a procedimentos endovasculares. Objetivo: O presente estudo visa descrever a técnica endovascular de balonamento temporário e embolização das artérias ilíacas internas durante o parto cesáreo, avaliar sua eficácia em reduzir o sangramento materno relacionado ao acretismo placentário, bem como relatar a segurança e o índice de complicações relacionadas ao tratamento endovascular. Materiais e métodos: Coorte retrospectiva de pacientes com diagnóstico pré-natal de acretismo placentário submetidas a tratamento endovascular de balonamento temporário e embolização das artérias ilíacas internas, seguido de histerectomia puerperal no nosso serviço, no período de janeiro de 2012 até novembro de 2016. Foram analisados dados relativos aos antecedentes gestacionais e cirúrgicos, achados de exames de imagem, achados histológicos, níveis de hemoglobina prévios, durante e após o parto, bem como volumes de hemoconcentrados administrados e taxa de complicações relacionadas ao procedimento endovascular. Resultados: Trinta e Siqueira FM 7 cinco pacientes foram submetidas ao manejo proposto durante o período estudado. Foi observado um volume médio de transfusão relacionado ao procedimento e perda sanguínea estimada de 540 ml e 1229 ml, respectivamente. Ocorreram complicações relacionadas ao procedimento endovascular em quatro pacientes, sendo um caso de necrose muscular glútea, um de lesão isquêmica cutânea superficial e dois casos de trombose arterial aguda de membros inferiores. Conclusão: O presente estudo demonstrou que o balonamento temporário e embolização das artérias ilíacas internas reduziu significativamente as necessidades transfusionais relacionadas ao parto nas pacientes com acretismo placentário, quando comparado com casos da literatura nos quais não foram realizadas intervenções endovasculares, com baixo índice de complicações relacionadas ao procedimento. / Introduction: Placenta accreta (PA) is the infrequent condition in which there is abnormal adherence of the trophoblastic tissue to the uterine wall. It\'s considered a major cause of puerperal bleeding, associated with high maternal morbimortality and need for blood products transfusion. Proposed treatments range from conservative to postpartum hysterectomy, combined or not to endovascular techniques. Objectives: to describe the detailed endovascular technique of temporary balloon occlusion followed by embolization of the internal iliac arteries (IIA) during cesarean section, evaluate the ability in reducing birth-related blood loss in patients with diagnosed PA and to assess safety and complications related to the endovascular procedure. Materials and methods: retrospective cohort of patients diagnosed with PA submitted to temporary balloting and embolization of the IAA followed by puerperal hysterectomy in our institution from January 2012 to November 2016. We recorded patient data such as gestational and surgical history, pre-natal radiological image findings, histopathological description, pre e postoperative hemoglobin levels and volume of blood products transfused in all patients. Follow up accounted for possible complications related to the procedure. Results: thirty-five patients were submitted to the approach during the study period. The median volume of packed red blood cells (RBC) and estimated blood loss were 540 ml and 1229 ml respectively. A total of 4 patients had complications attributed to the endovascular procedure - one case of Siqueira FM 9 deep glute tissue necrosis, one of superficial tissue necrosis and two cases of acute arterial thrombosis of the inferior limbs. Conclusion: the present study demonstrated that temporary ballooning and embolization of the IAA was able to significantly reduce birth-related blood loss and transfusion needs in patients with PA when compared to other literature series where no endovascular procedures were performed, with a low rate of procedure-related complications.

Abstract Although in Finland the incidence of maternal and neonatal mortality in labor is very low, labor carries some risks. This study focused on two major complications in labor: fetal asphyxia and maternal hemorrhage. The roles of fetal electrocardiographic ST-analysis (STAN) and pelvic artery embolization in the prevention and management of these complications were investigated. Intrapartum fetal monitoring aims at a timely detection of fetal hypoxemia. When non-selected parturients were randomly assigned to be monitored during labor either by STAN or conventional cardiotocography, no differences between the groups were detected in terms of neonatal outcome and operative delivery rates. Only the incidence of fetal blood sampling was lower in the STAN group. In the interpretation of the STAN tracings according to the guideline matrix provided by the STAN manufacturer, the interobserver agreement was moderate; in terms of clinical decision -making as to whether to intervene in the labor, this agreement varied from moderate to good among STAN-trained obstetricians. The aim of prophylactic pelvic artery occlusion balloon catheterization, with or without embolization, is to reduce hemorrhage in elective cesarean operations in patients with placenta accreta. Furthermore, pelvic arterial embolization may be performed post partum if bleeding continues after cesarean hysterectomy, or may serve as an alternative to hysterectomy. In the present study, pelvic artery catheterization and embolization did not reduce blood loss during cesarean delivery, nor did it decrease the need to perform hysterectomy in patients with placenta accreta. In the management of massive postpartum hemorrhage, pelvic artery embolization was most successful in patients with uterine atony, with a success rate of 75% in achieving hemostasis. However, the angiographic method included risk of complications, the most hazardous being thromboembolic complications. To conclude, STAN does not provide improvement in intrapartum fetal monitoring when compared to cardiotocography, but the need for fetal blood sampling is reduced. This may relate to the fact that subjective interpretation of STAN data is moderate at best. Prophylactic catheterization and embolization of pelvic arteries does not improve the surgical outcome of patients with placenta accreta. In the management of postpartum hemorrhage, pelvic artery embolization should be considered, especially in cases with uterine atony.

Introduction: The reason for the inability of performing the liver resection for colorectal carcinoma metastasis is usually insufficient remnant liver parenchyma after liver resection (future liver remnant volume - FLRV). The current standard method of increasing FLRV is the embolization of the branch of portal vein (portal vein embolization - PVE) on the side of the tumor, and then suspended after hypertrophy of the non-embolised lobe liver resection. Unfortunately, there are some patients who do not increase liver volume despite perfectly executed PVE. Besides that, FLRV occurs during the time necessary for hypertrophy progression of metastatic disease. Therefore, we are trying to find the appropriate way to encourage the growth of remaining liver parenchyma and accelerate hypertrophy of the contralateral liver lobe. From our previous experience (IGA MZ NS 10240), it is possible to be optimistic that there hope is the way of hematopoietic progenitor cells (HPC - adult stem cells) after previous PVE to non-embolised branches of the portal vein. These cells do not only accelerate liver regeneration, but are also able to improve its function (function of the liver) which is especially important for patients after neoadjuvant chemotherapy (steatohepatitis or steatofibrosis), and for patients with...