Acute pancreatitis is an inflammatory process that initiates with the damage of the pancreatic acinar cells and can also involve other organs and peripancreatic tissues. Vascular alterations are proposed as factors that contribute significantly to the morbidity of patients with pancreatitis. However, few studies were directed to understand these alterations and the underlying mechanisms. In this way, the objective of this study was to investigate vascular changes caused by acute pancreatitis induced by common bile duct obstruction (CBDO) on the vascular reactivity of rat mesenteric artery, in order to generate scientific knowledge about the mechanisms involved in this condition and enable future approaches that lead to a better treatment of this disease in humans. For this purpose, adult male Wistar rats were used (220-300 g) and divided into two groups: (i) sham animals, which were submitted to surgery procedure without obstruction of the duct and (ii) CBDO animals which were submitted to surgery procedure and obstruction of the common bile duct. After 24 or 48 h of this surgery, animals were anesthetized and the superior mesenteric artery was removed. Serum samples were also obtained for amylase determination. Mesentery artery rings were obtained (1-2 mm) and used for in vitro reactivity experiments and measurement of nitric oxide (NO) and superoxide anion (O2 -). For the reactivity experiments, the rings were mounted in isolated organ chambers and cumulative concentration-response curves to acetylcholine or phenylephrine were obtained. For evaluating the production of NO and O2 -, rings were incubated with specific fluorescent dyes. Levels of serum amylase were augmented in animals with CBDO after 24 (p<0.05) or 48 h (p<0.001) of obstruction, when compared with sham group, confirming the induction of pancreatitis. Mesenteric rings from CBDO animals showed decreased relaxing response for acetylcholine or contractile response to phenylephrine after 24 or 48 h of induction of pancreatitis, when compared with sham group. Our data also showed an increase in NO (p<0,05) and O2 - (p<0,05) production in the rings collected after 48 h of the surgical procedure, but not after 24 h. These findings showed that acute pancreatitis induction by CBDO impaired relaxation and contractile response, possibly by mechanisms that are triggered by increased NO and O2 - production, probably associated with the inflammatory process. Additional studies are needed to identify the mechanisms underlying these vascular effects of acute pancreatitis. / A pancreatite aguda é um processo inflamatório que se desenvolve a partir de lesão dos ácinos pancreáticos e também pode envolver tecidos peripancreáticos e outros órgãos. Alterações na função vascular são propostas como fatores que contribuem sobremaneira para a morbidade dos pacientes com pancreatite, entretanto poucos estudos foram direcionados para entender estas alterações e os mecanismos subjacentes. Com base nessas premissas, o objetivo do presente estudo foi investigar as alterações vasculares provocadas pela pancreatite aguda induzida por obstrução do ducto biliopancreático (ODBP) sobre a reatividade de artéria mesentérica de ratos, com o intuito de gerar conhecimento científico sobre os mecanismos envolvidos nesta condição e permitir abordagens futuras que levem ao melhor tratamento desta doença em humanos. Para tanto, foram utilizados ratos machos adultos Wistar (220-300 g) que foram divididos em grupos falso operado (Sham), no qual somente houve a cirurgia, sem obstrução do ducto, ou ODBP, o qual foi submetido a cirurgia e obstrução do ducto biliopancreático. Em seguida, os animais dos diferentes grupos foram eutanasiados após 24 ou 48 h e a artéria mesentérica superior foi removida, bem como soro foi separado para dosagem de amilase. Desta artéria foram obtidos anéis com endotélio (1-2 mm) que foram utilizados para a realização dos experimentos de reatividade in vitro e mensuração de óxido nítrico (NO) e ânion superóxido (O2 -). Para os experimentos de reatividade, os anéis foram montados em sistema de banho de órgão isolado e foi testada sua resposta relaxante ou contrátil, mediante estimulação com acetilcolina (ACh) ou fenilefrina (Fen) respectivamente. Para avaliar a produção de NO e O2 -nos anéis dos animais dos diferentes grupos, foram utilizadas sondas fluorescentes específicas para estes radicais livres. Nos animais com ODBP foram encontradas concentrações séricas de amilase elevadas após 24 (p<0,05) ou 48 h (p<0,001), quando comparados ao grupo sham, confirmando a indução da pancreatite. Os anéis dos animais com ODBP demonstraram uma diminuição da resposta relaxante à acetilcolina ou contrátil à fenilefrina após 24 ou 48 h da indução da pancreatite, quando comparados aos animais do grupo sham. Também foi observado aumento na produção de NO (p<0,05) e de O2 - (p<0,05) nos anéis coletados após 48 h, mas não 24 h da indução da pancreatite. Estes achados mostraram que a indução da pancreatite aguda por ODBP prejudica tanto a resposta relaxante quanto a contrátil de anéis de artéria mesentérica, por mecanismos que possivelmente são desencadeados pelo aumento na produção de NO e O2 -, provavelmente associado com o processo inflamatório. Entretanto, experimentos adicionais são necessários para identificar os mecanismos pelos quais a pancreatite aguda causa estes efeitos.

Nos transplantes intervivos de fígado em adultos, o enxerto possui apenas uma artéria segmentar, cujo calibre e extensão são geralmente pequenos. Assim, a distância entre essa artéria do enxerto e a artéria hepática do receptor geralmente é grande e os calibres desproporcionais, tornando tecnicamente difícil a reconstrução arterial hepática. Nestes casos, pode-se utilizar um autoenxerto vascular de interposição para facilitar o procedimento, evitando-se assim complicações cirúrgicas. Objetivo: O presente trabalho se propôs a comparar a artéria mesentérica inferior (AMI), artéria esplênica (AE), artéria epigástrica inferior (AEI), ramo descendente da artéria circunflexa femoral lateral (ACFL) e artéria hepática própria (AHP) como opções de autoenxerto de interposição em transplantes de fígado intervivos em adultos. Método: Foram dissecados 16 cadáveres frescos e coletados as referidas artérias de cada um deles. As variáveis estudadas foram diâmetro do orifício proximal, do distal e comprimento. O diâmetro proximal da AHP e os diâmetros distais AE, AMI, AEI e ramo descendente da ACFL foram comparados ao diâmetro distal da AHD. Os diâmetros proximais e distais da AE, AEI e ramo descendente da ACFL foram comparados entre si para avaliar ganho de calibre. Resultados: Todas as artérias, exceto a AMI, apresentaram diferença estatisticamente significante em relação à AHD quanto à diâmetro. Em termos de ganho de calibre, as artérias apresentaram diferença estatisticamente significante. Todas as artérias, exceto a AHP, apresentaram comprimento de 3 cm. Conclusão: A AMI apresentou a melhor compatibilidade de diâmetro com a AHD e comprimento suficiente para uso como autoenxerto. A AHP, AE, AEI e o ramo descendente da ACFL apresentam calibre estatisticamente diferente da AHD. Destas, somente a AHP não apresentou média de comprimento suficiente para uso em transplante de fígado intervivos / In living donor liver transplantation, the graft presents only a segmental artery, which usually has small diameter and short extension. In these cases, an interpositional arterial autograft can be used in order to obtain vascular extension and better diameter compatibility, making the procedure easier and avoiding surgical complications. Aim: We compared the inferior mesenteric artery (IMA), the splenic artery (SA), the inferior epigastric artery (IEA), the descending branch of the lateral circumflex femoral artery (LCFA) and the proper hepatic artery (PHA) as options of interpositional autograft in living donor liver transplantation. Method: Segments of at least 3 cm of all five arteries were harvested from 16 fresh adult cadavers from both genders through standardized dissection. The analyzed measures were proximal and distal diameter and length. The proximal diameter of RHA and the distal diameter of SA, IMA, IEA and the LCFA were compared to the distal diameter of the RHA. The proximal and distal diameters of the SA, IEA and the LCFA were compared to study caliber gain of each artery. Results: All arteries, except the IMA, showed statistical significant difference in relation to the RHA in terms of diameter. Regarding caliber gain, the arteries demonstrated statistical significant difference. All arteries, except PHA, presented length equal to 3 cm. Conclusion: The IMA demonstrated the best compatibility with the RHA in terms of diameter and has shown sufficient length to be employed as interpositional graft. The PHA, the SA, the IEA and the LCFA presented statistically significant different diameters when compared to the RHA. Among these vessels, only the PHA did not show sufficient mean length

Abstract Endovascular aneurysm repair (EVAR) is a minimally invasive alternative to open surgery to exclude an abdominal aortic aneurysm from the circulation to avert a rupture. The aim of this thesis was to evaluate the early and mid-term results of EVAR using the Zenith® stent-graft (Cook Inc, Bloomington, IN, USA) in asymptomatic and symptomatic abdominal aortic aneurysm (AAA) patients in three Finnish university hospitals. Furthermore, the aim was to study whether preoperative embolization of the inferior mesenteric artery (IMA) before EVAR decreases the incidence of a type II endoleak or has an effect on the aneurysm sac shrinkage. Finally, the results after secondary interventions for a type II endoleak were evaluated. Two hundred six patients underwent elective endovascular repair of an intact AAA. The use of the Zenith® stent-graft was associated with good early and mid-term results. The thirty-day mortality rate (2.9%) was in accordance with other EVAR studies. Only one late aneurysm-related death occurred in this series, whilst no patients died of a late aneurysm rupture. No stent-graft migrations or fractures were observed. Endoleak, defined as persistent blood flow outside the graft and within the aneurysm sac, remains a long-term problem with EVAR. The overall endoleak incidence was 34.6%. A type II endoleak (retrograde perfusion via aortic side branches) occurred in 52 patients (25.4%). EVAR was performed for 14 patients with a symptomatic, unruptured AAA. The median delay from admission to intervention was 4 days. EVAR of a symptomatic, unruptured AAA was associated with a favourable outcome even in patients with a very high operative risk. There were no perioperative deaths. Altogether forty patients treated at Kuopio University Hospital had a patent IMA on preoperative computed tomography (CT) and were treated successfully with coil embolization before EVAR. Thirty-nine patients who underwent EVAR at Oulu University Hospital without preoperative embolization of a patent IMA served as a control group. Preoperative coil embolization of the IMA significantly reduced the incidence of type II endoleaks after EVAR, but the present study failed to show any influence on late postoperative aneurysm sac shrinkage. Overall, 14 patients underwent a secondary intervention to repair the type II endoleak. Ten patients had transarterial embolization and four patients had translumbar embolization. The results were unsatisfactory; clinical success after the first secondary intervention was achieved in only two patients in the transarterial embolization group and three patients in the translumbar embolization group. These results seem to favour direct translumbar embolization rather than transarterial embolization. In conclusion, EVAR with the Zenith® stent-graft is effective in excluding AAAs from the circulation and is associated with good mid-term results.