Repeatability of the "flash-replenishment" method in contrast-enhanced ultrasound for the quantitative assessment of hepatic microvascular perfusion

This study aimed to evaluate the feasibility and repeatability of the flash-replenishment method in contrast-enhanced ultrasound (CEUS) perfusion imaging and assess quantitatively microvascular perfusion in the liver. Twenty healthy New Zealand rabbits were submitted to CEUS perfusion imaging with continuous intravenous infusion. Using flash-replenishment kinetics, the dynamic process of depletion and refilling of microbubble contrast agent was recorded. The hepatic microvascular perfusion parameters were calculated, including region of interest, peak intensity (PI), area under the curve (AUC), and hepatic artery to vein transit time (HA-HVTT). A consistency test was performed for multiple measurements by the same operator and blind measurements by two different operators. The hepatic perfusion imaging of 3×108 bubbles/min had minimal error and the best imaging effect and repeatability. The variability of the perfusion parameter measured at 3 cm depth under the liver capsule was at a minimum with coefficient of variation of 3.9%. The interclass correlation coefficient (ICC) of measurements taken by the same operator was 0.985, (95% confidence interval, CI=0.927-0.998). Measurements taken by two operators had good consistency and reliability, with the ICC of 0.948 (95%CI=0.853-0.982). The PI and AUC of liver parenchyma after reperfusion were lower than before blocking; and HA-HVTT was significantly longer than before blocking (P<0.05). The flash-replenishment method in CEUS perfusion imaging showed good stability and repeatability, which provide a valuable experimental basis for the quantitative assessment of hepatic microvascular perfusion in clinical practice.

Portal Vein Dopplerflowmetry in healthy sheep according to age / Dopplerfluxometria da veia portal em ovinos hígidos de acordo com a idade

Pulsed Doppler ultrasound was used to evaluate portal blood flow, portal velocity and portal congestion index in 24 healthy sheep divided into groups (lambs, yearlings and ewes), according to age. Measurements were performed at the 11th right intercostal space using ideal insonation angle and uniform insonation method. Mean values obtained in each group were compared with one-way ANOVA, followed by Tukey post-hoc test. Portal velocity and portal blood flow were statistically similar between the groups (P>0.05). Mean portal velocity were 17.75; 17.13 and 16.75; while mean portal blood flow were 26.65; 31.04 and 24.32 for lambs, yearlings and ewes, respectively. Portal congestion index was statistically distinct between the groups and values for lambs, yearlings and ewes were 0.009; 0.058 and 0.09, respectively (P<0.01). Statistical differences were observed in portal vein diameter, portal vein area and portal congestion index between the groups, presumably due to influence of weight and not to age.(AU)

A ultrassonografia com Doppler pulsado foi utilizado para avaliar o fluxo sanguíneo portal, velocidade portal e índice de congestão portal em 24 ovinos saudáveis divididos em grupos (cordeiros, borregos e ovelhas), de acordo com a idade. As medições foram realizadas no 11o espaço intercostal direito utilizando ângulo de insonação ideal e método de inclusão uniforme. Os valores médios obtidos em cada grupo foram comparados com ANOVA, seguido pelo teste post-hoc de Tukey. A velocidade portal e o fluxo de sangue portal foram estatisticamente semelhantes entre os grupos (P>0,05). A velocidade portal média foram 17,75; 17,13 e 16,75; enquanto o fluxo de sangue portal médios foram 26,65; 31,04 e 24,32 para cordeiros, borregos e ovelhas, respectivamente. O índice de congestão portal foi estatisticamente diferente entre os grupos e os valores para cordeiros, novilhos e ovelhas foram 0,009; 0,058 e 0,09, respectivamente (P<0.01). Observaram-se diferenças estatísticas nos diâmetros da veia porta, na área da veia porta e nos índices de congestão portal entre os grupos, provavelmente devido à influência do peso e não pela idade.(AU)

Doppler hepático na pré-eclâmpsia e na síndrome HELLP / Doppler ultrasonography of the liver in pre-eclampsia and HELLP syndrome

O fígado está entre os múltiplos órgãos que podem ser afetados na pré-eclâmpsia, e a função hepática pode ser gravemente prejudicada na síndrome HELLP. A ultrassonografia com Doppler constitui um método não invasivo que pode ser usado para o estudo da circulação hepática durante a gravidez. Com o objetivo de apresentar as evidências científicas disponíveis sobre as alterações do fluxo hepático na gravidez, foi realizada pesquisa da literatura mundial por meio das bases de dados MEDLINE/PubMed e LILACS. Em estudos de Dopplerfluxometria e Dopplervelocimetria, isoladamente ou associados ao eletrocardiograma e cardiografia por impedância, foram observadas alterações na circulação hepática durante a gravidez complicada por pré?eclâmpsia e síndrome HELLP. Entre os desafios para a pesquisa nesse campo destacamos a necessidade de aperfeiçoamento da técnica de exame, o estabelecimento de curvas de normalidade para as gestantes brasileiras, de indicadores de agravamento da pré?eclâmpsia e a aplicação potencial do método para o estudo da hipertensão crônica na gravidez.(AU)

The liver is among multiple organs that may be affected in pre-eclampsia, and liver function can be impaired in HELLP syndrome. Doppler ultrasonography of the liver provides a noninvasive method to study liver circulation during pregnancy. This paper reviews scientific evidence available in MEDLINE/ Pubmed and LILACS databases. Doppler studies on hepatic blood flow, flow velocities and vascular resistance indices, isolated or combined with Doppler?electrocardiography and impedance cardiography, observed changes in pregnancies complicated by pre?eclampsia and HELLP syndrome. Challenges to this research topic include improvements in Doppler examination techniques, establishment of normal values for Brazilian pregnant women, predictors for severe pre?eclampsia and potential use of hepatic Doppler use in chronic hypertension as well.(AU)

Artéria hepática acessória: incidência e distribuição / Accessory hepatic artery: incidence and distribution

As variações anatômicas das artérias hepáticas são comuns. A identificação pré-operatória dessas variações é importante para prevenir lesão inadvertida e complicações potencialmente letais durante procedimentos abertos e endovasculares. Objetivo: Avaliar a incidência, o trajeto extra-hepático e a presença de ramos laterais das artérias hepáticas acessórias definidas como um suprimento arterial adicional para o fígado na presença de artéria hepática normal. Métodos: Oitenta e quatro cadáveres humanos masculinos foram dissecados através de laparotomia mediana transperitoneal. A aorta supracelíaca, o eixo celíaco e as artérias hepáticas foram dissecados, e suas trajetórias foram identificadas para descrever os padrões dos ramos arteriais...

Anatomic variations of the hepatic arteries are common. Preoperative identification of these variations is important to prevent inadvertent injury and potentially lethal complications during open and endovascular procedures. Objective: To evaluate the incidence, extra-hepatic course, and presence of side branches of accessory hepatic arteries, defined as an additional arterial supply to the liver in the presence of normal hepatic artery. Methods: Eighty-four human male cadavers were dissected using a transperitoneal midline laparotomy. The supra-celiac aorta, celiac axis, and hepatic arteries were dissected, and their trajectories were identified to describe arterial branching...

Pathophysiology of Portal Hypertension, What's New? / 대한소화기학회지

Portal hypertension (PHT) is associated with changes in the intrahepatic, systemic and portosystemic collateral circulations. Alteration in vasoreactivity (vasodilation and vasoconstriction) plays a central role in the pathogenesis of PHT by contributing to increased intrahepatic resistance, hyperdynamic circulation and the expansion of the collateral circulation. PHT is also importantly characterized by changes in vascular structure; termed vascular remodeling, which is an adaptive response of the vessel wall that occurs in response to chronic changes in the environment such as shear stress. Angiogenesis, the sprouting of new blood vessels, also occurs in PHT, especially in the expansion of the portosystemic collateral circulation. These complementary processes of vasoreactivity, vascular remodeling and angiogenesis represent important targets in the research for the treatment of portal hypertension.

Hemodynamic alterations in cirrhosis and portal hypertension / 대한간학회지

Portal hypertension (PHT) is associated with hemodynamic changes in intrahepatic, systemic, and portosystemic collateral circulation. Increased intrahepatic resistance and hyperdynamic circulatory alterations with expansion of collateral circulation play a central role in the pathogenesis of PHT. PHT is also characterized by changes in vascular structure, termed vascular remodeling, which is an adaptive response of the vessel wall that occurs in response to chronic changes in the environment such as shear stress. Angiogenesis, the formation of new blood vessels, also occurs with PHT related in particular to the expansion of portosystemic collateral circulation. The complementary processes of vasoreactivity, vascular remodeling, and angiogenesis represent important targets for the treatment of portal hypertension. Systemic and splanchnic vasodilatation can induce hyperdynamic circulation which is related with multi-organ failure such as hepatorenal syndrome and cirrhotic cadiomyopathy.

Portal hypertensive response to kinin

Portal hypertension is the most common complication of chronic liver diseases, such as cirrhosis. The increased intrahepatic vascular resistance seen in hepatic disease is due to changes in cellular architecture and active contraction of stellate cells. In this article, we review the historical aspects of the kallikrein-kinin system, the role of bradykinin in the development of disease, and our main findings regarding the role of this nonapeptide in normal and experimentalmodels of hepatic injury using the isolated rat liver perfusion model (mono and bivascular) and isolated liver cells. We demonstrated that: 1) the increase in intrahepatic vascular resistance induced by bradykinin is mediated by B2 receptors, involving sinusoidal endothelial and stellate cells, and is preserved in the presence of inflammation, fibrosis, and cirrhosis; 2) the hepatic arterial hypertensive response to bradykinin is calcium-independent and mediated by eicosanoids; 3) bradykinin does not have vasodilating effect on the pre-constricted perfused rat liver; and, 4) after exertion of its hypertensive effect, bradykinin is degraded by angiotensin converting enzyme. In conclusion, the hypertensive response to BK is mediated by the B2 receptor in normal and pathological situations. The B1 receptor is expressed more strongly in regenerating and cirrhotic livers, and its role is currently under investigation.

Hipertensão portal é a complicação mais comum das doenças crônicas do fígado, tais como cirrose. A resistência intravascular aumentada observada na doença hepática é devida a alterações na arquitetura celular e contração ativa das células estreladas. Neste trabalho revisamos aspectos históricos do estudo do sistema calicreína-cinina e os resultados de nossos estudos do papel deste nonapeptídeo no controle do tono vascular intra-hepático em condições normais e modelos experimentais de agressão hepática usando a perfusão de fígado isolado de rato (mono e bivascular) e células hepáticas isoladas. Nós demonstramos que: 1) o aumento da resistência vascular intrahepática induzido pela bradicinina é mediado por receptores B2, envolve a participação de células endoteliais sinusoidais e células estreladas e não é alterada pela presença de inflamação, fibrose ou cirrose; 2) a resposta hipertensiva induzida pela bradicinina no sistema arterial hepático é cálcio-independente emediada por eicosanóides; 3) bradicinina não tem efeito dilatador na circulação intra-hepática; 4) após exercer efeito vasoconstritor intra-hepático, a bradicinina é degradada pela enzima conversora de angiotensina. Em conclusão, a resposta hipertensiva à bradicinina é mediada pelo receptor B2 em condições normais e patológicas. Receptor B1 é expresso mais fortemente nos fígados em regeneração e cirróticos e seu papel está sob investigação.

effects of hypothermic versus normothermic cardiopulmonary bypass on hepatic blood flow

To explore Trans-esophageal Echo [TEE] as a monitoring device for hepatic blood flow during cardiac1 surgery and to correlate between the hepatic venous blood flow measurements and the liver function tests during normothermic and hypothermic cardiopulmonary bypass. Forty patients scheduled for cardiac surgery were randomly divided into 2 groups: group 1 [Gl] undergoing normothermic cardiopulmonary bypass [CPB] and group 2 [G2] undergoing hypothermic CPB. Serum AST, ALT, billirubin and hyalurinic acid levels were measured before, during and 6 hours after the bypass. During these same phases, TEE was used to measure both cardiac index [Cl] and middle hepatic vein blood flow. During CPB there were no significant differences in demographic data, AST, ALT or billirubin levels between the 2 groups. There was, however, a significant increase [P<0.001], in both groups, in serum hyalurinic acid levels during CBP in relation to the baseline and in Cl 6 hours after bypass in relation to pre and intra bypass phases. The middle hepatic venous blood flow was significantly higher amongst Gl patients six hours following the procedure in relation to the pre and intra bypass phases, whereas G2 patients showed a significant decrease in middle hepatic venous flow during the bypass followed by a significant increase 6 hours after the procedure in relation to the baseline. Hepatic venous blood flow is reduced significantly more during hypothermic bypass than during normothermic bypass. This may cause disturbances in sinusoidal endothelial cell [SEC] function. However, this change may be well tolerated by the healthy liver. Multiplan TEE may be used to monitor hepatic blood flow during CPB

Non invasive prediction of varices in Egyptian cirrhotic patients

Cirrhotic patients frequently undergo screening endoscopy for the presence of varices. In the future, this social and medical burden will increase due to the greater number of patients with chronic liver disease and their improved survival. In this study, our aim was to develop a predictive model using independent risk factors for the presence of varices in the enrolled patients. 200 patients with liver cirrhosis with no history of variceal haemorrhage were subjected to clinical examination; laboratory investigations [CBC, Liver biochemical profile, serum urea and creatinine], modified Child-Pugh score and MELD score were calculated. Abdominal ultrasonography and Doppler study of the portal and splenic veins studying the liver size, the presence of periportal thickening, hepatic veins flow pattern, the splenic longest axis and volume, the presence of ascites and collaterals. Portal vein and splenic vein diameter, patency, cross sectional area, mean flow velocity, blood flow volume congestion index and direction of flow of portal vein were calculated. Platelets count/Splenic diameter ratio and Right liver lobe diameter/ albumin ratio were calculated for all patients. Upper endoscopy was done where oesophageal varices were graded according to modified Thakeb classification. This study revealed that 83% of patients had oesophageal varices; 52% had small sized oesophageal varices and 31% had large sized oesophageal varices. In patients with varices; 12% had biphasic and 22.9% had monophasic hepatic veins flow pattern, with p value of 0.002. Portal vein direction of flow was bidirectional in 22.9% and Hepatofugal in 9.6% with a p value of 0.004. The portal vein velocity of 9.3 +/- 2.3cm/ sec with a p value of <0.001 and the ascites was present in 77% of patients with a p value of 0.005. In patients with large sized varices; shrunken liver was present in 83.1% of patients with a p value of 0.005 and serum albumin <2.5gm/dl with a p value of 0.008. Hepatic veins flow pattern [biphasic and monophasic], portal vein direction of flow [hepatofugal and bidirectional], decreased portal vein velocity and the presence of ascites [moderate and marked] were the significant variables for prediction of presence of varices. Shrunken liver and the low serum albumin were the significant variables for prediction of large varices

Liver histological, portal flow and plasmatic nitric oxide alterations caused by biliary obstruction and drainage in rats / Alterações histológicas, do fluxo portal e do óxido nítrico plasmático em ratos submetidos à obstrução/desobstrução biliar

PURPOSE: To evaluate liver alterations caused by biliary obstruction and drainage. METHODS: Thirty-nine male Wistar rats were randomly distributed in 4 groups: BO (n=18) bile duct ligation for 20 days, with a periodic evaluation of liver histological alterations, Doppler echography portal flow and measurements of NO and malondialdehyde (MDA); BO/DB (n=13) bile duct occlusion for 20 days followed by biliary drainage by choledochoduodenal anastomosis, 5 days follow-up, same BO group parameters evaluations; group CED (n=4) sham operation and portal flow evaluation trough 20 days; CHB (n=4) sham operation, with hepatic biopsy on 25th day and followed-up trough 25 days, by the same parameters of group BO, with exception of portal flow. Direct bilirubin (DB) and alkaline phosphatase (AP) were evaluated in the group BO, BO/DB and CHB. RESULTS: The bile duct ligation led to an increase of DB and AP, development of liver histological alterations, reduction of portal flow and increase of plasmatic NO and of MDA levels. The bile duct clearing resulted in a reduction of DB, AP, NO, MDA histological alterations and increase of portal flow. CONCLUSION: The biliary occlusion resulted in cholestasis and portal flow reduction, besides the increase of plasmatic NO and of hepatic MDA levels, and histological liver alterations, with a tendency of normalization after the bile duct clearing.

OBJETIVO: Avaliar alterações hepáticas resultantes do processo de obstrução/desobstrução biliar. MÉTODOS: Trinta e nove ratos Wistar foram distribuídos aleatoriamente em 4 grupos: OB (n=18), oclusão biliar, seguimento de 20 dias, avaliação das alterações histológicas hepáticas, do fluxo portal e dosagens de NO e de malondialdeído (MDA); grupo OB/DB (n=13) oclusão biliar por 20 dias seguida de desobstrução biliar por anastomose colédoco-duodenal, seguimento por 5 dias e avaliação dos mesmos parâmetros do grupo BO; grupo CED (n=4) operação simulada, avaliação do fluxo portal e seguimento por 25 dias; grupo CHB (n=4) operação simulada com biópsia hepática no 25º dia, e seguido por 25 dias com avaliação periódica dos mesmos parâmetros do grupo BO, com exceção da ecografia Doppler. Nos grupos BO, OB/DB e CHB foram avaliadas também a bilirrubina direta (BD) e a fosfatase alcalina (FA). RESULTADOS: A oclusão do colédoco causou aumento da BD e da FA, desenvolvimento de alterações hepáticas, redução do fluxo portal, com aumentos do NO plasmático e do MDA. A desobstrução biliar resultou na redução da BD, da FA, das alterações hepáticas, aumento do fluxo portal e redução do NO e do MDA. CONCLUSÃO: A obstrução biliar resultou em colestase, alterações histológicas hepáticas, diminuição do fluxo portal, aumentos do NO plasmático e MDA hepático, com tendência à normalização após a desobstrução biliar.

Remodeling of hepatic vascular changes after specific chemotherapy of schistosomal periportal fibrosis

Hepatosplenic schistosomiasis was the first human disease in which the possibility of extensive long standing hepatic fibrosis being degraded and removed has been demonstrated. When such changes occurred, the main signs of portal hypertension (splenomegaly, esophageal varices) progressively disappeared, implying that a profound vascular remodeling was concomitantly occurring. Hepatic vascular alterations associated with advanced schistosomiasis have already been investigated. Obstruction of the intrahepatic portal vein branches, plus marked angiogenesis and compensatory hyperplasia and hypertrophy of the arterial tree are the main changes present. However, there are no data revealing how these vascular changes behave during the process of fibrosis regression. Here the mouse model of pipestem fibrosis was used in an investigation about these vascular alterations during the course of the infection, and also after treatment and cure of the disease. Animals representing the two polar hepatic forms of the infection were included: (1) "isolated granulomas" characterized by isolated periovular granulomas sparsely distributed throughout the hepatica parenchyma; and (2) 'pipestem fibrosis' with periovular granulomas and fibrosis being concentrated within portal spaces, before and after treatment, were studied by means of histological and vascular injection-corrosion techniques. Instances of widespread portal vein obstruction of several types were commonly found in the livers of the untreated animals. These obstructive lesions were soon repaired, and completely disappeared four months following specific treatment of schistosomiasis. Treatment was accomplished by the simultaneous administration of praziquantel and oxamniquine. The most impressive results were revealed by the technique of injection of colored masses into the portal system, followed by corrosion in strong acid. The vascular lesions of non-treated pipestem fibrosis were represented...

Pyruvate kinase activation and lipoperoxidation after selective hepatic ischemia in Wistar rats / Ativação da piruvato quinase e lipoperoxidação após isquemia hepática seletiva em ratos Wistar

PURPOSE: Hepatic ischemia and reperfusion can cause several problems in hepatic surgery. The aim of this study was to determine pyruvate kinase activation and lipid peroxidation after hepatic ischemia. METHODS: Twenty-four Wistar rats were submitted to 90 minutes of selective liver ischemia and 15 minutes of reperfusion. Twelve animals were submitted to selective liver ischemia and reperfusion (Group A) and the other 12 were submitted to sham operation (Group B). After 15 minutes of reperfusion, the following parameters were measured: mean arterial pressure (MAP), alanine aminotransferase (ALT), glycemia (GLY), hepatic glycogen (GH), pyruvate kinase (PK) activation, hepatic glutathione (GSH) and malondialdehyde (MDA). Analysis of the results were made by the Student t-test and has been considered significant difference for p<0.05. RESULTS: A and B were differents for all parameters analized. CONCLUSION: The animals of group A showed reperfusion syndrome with a fall in MAP, activation of glycid metabolism through the glycolitic pathway and presence of lipid peroxidation compared to group B.

OBJETIVO: A isquemia e reperfusão hepática podem causar graves repercussões hepatocelulares em cirurgias hepáticas. O objetivo deste estudo foi determinar o comportamento da piruvato EM PORTUGUES quinase e a lipoperoxidação após isquemia hepática. MÉTODOS: Foram utilizados vinte e quatro ratos Wistar machos divididos em dois grupos. Doze animais foram submetidos a 90 minutos de isquemia hepática seletiva e reperfusão hepática de por 15 minutos (pressão arterial média (PAM), alanina aminotransferase (ALT), glicemia (GLI), gicogênio hepático (GH), ativação da piruvato quinase (PQ), glutationa hepática (GSH) e malondialdeído (MDA). Os resultados foram analisados utilizando o teste t de Student sendo as diferenças consideradas significativas para p<0,05. RESULTADOS: Verificou-se diferença significativa entre os grupos em todos os parâmetros analisados. CONCLUSÃO: Verificou-se que os animais do grupo A mostraram síndrome de reperfusão com queda da PAM, ativação do metabolismo da glicose através da via glicolítica e presença de lipoperoxidação quando comparada com o grupo B.

Hepatic microcirculatory failure / Falência microcirculatória hepática

Liver ischemia has been considered a frequent problem in medical practice, and can be associated to a number of surgical and clinical situations, such as massive hepatic resections, sepsis, liver trauma, circulatory shock and liver transplantation. After restoring blood flow, the liver is further subjected to an additional injury more severe than that induced by ischemia. On account of the complexity of mechanisms related to pathophysiology of ischemia and reperfusion (I/R) injury, this review deals with I/R effects on sinusoidal microcirculation, especially when steatosis is present. Alterations in hepatic microcirculation are pointed as a main factor to explain lower tolerance of fatty liver to ischemia-reperfusion insult. The employment of therapeutic strategies that interfere directly with vasoactive mediators (nitric oxide and endothelins) acting on the sinusoidal perfusion seem to be determinant for the protection of the liver parenchyma against I/R. These approaches could be very suitable to take advantage of marginal specimens as fatty livers, in which the microcirculatory disarrangements hamper its employment in liver transplantation.

A isquemia hepática é um problema relativamente freqüente na prática clínica, sobrevindo em situações diversas como ressecções hepáticas maciças, sepse, trauma hepático extenso, choque circulatório e transplante hepático. Durante a restauração do fluxo sanguíneo, o fígado é submetido a uma agressão adicional ainda mais intensa que aquela imposta pela isquemia. Devido à complexidade dos diversos mecanismos envolvidos na fisiopatologia da lesão por isquemia e reperfusão (I/R) hepática, esta revisão se limitará a discorrer sobre os efeitos da I/R na microcirculação sinusoidal, com ênfase para as alterações microvasculares que tomam lugar no fígado esteatótico pós-isquêmico. O desarranjo microcirculatório é apontado como um importante fator para explicar a reduzida tolerância do fígado esteatótico ao insulto isquêmico. O desenvolvimento de estratégias terapêuticas capazes de interferir diretamente com os mediadores vasoativos (óxido nítrico e endotelinas) relacionados ao déficit perfusional será determinante para a proteção do parênquima hepático frente às alterações induzidas pela I/R. Esses recursos seriam de especial interesse para o aproveitamento de fígados marginais, cuja falência microcirculatória compromete sobremaneira sua utilização para o transplante hepático.

Hepatic Arterioportal Shunts: Dynamic CT and MR Features

With the increased temporal resolution available in dynamic computed tomography (CT) and magnetic resonance imaging (MRI), hepatic arterioportal shunts are now more frequently encountered than in the past. The condition occurs in various hepatic diseases in which portal or hepatic venous flow is compromised. The underlying mechanism and the degree of shunt affect its appearance at dynamic imaging. The dynamic CT and MRI findings have been summarized as early enhancement of peripheral portal veins, and wedge-shaped transient parenchymal enhancement during the hepatic arterial phase. Recognition of arterioportal shunt can suggest the presence of a previously unsuspected disorder and avoids false-positive diagnosis or overestimation of a hepatic disease. Familiarity with the pathophysiology of arterioportal shunt also allows investigation of the hepatic hemodynamic changes occurring in various hepatic diseases.

Hipertensión portal: várices esófagicas y hemorragía digestiva / Portal hypertension: esophageal varices and gastrointestinal bleeding

El alcoholismo tiene en Chile una elevada prevalencia (entre 12 y 15 por ciento de la población adulta) al igual que la cirrosis hepática en general y la de Laennec en particular. Ello explica la frecuencia que alcanza, entre nuestros pacientes, el síndrome de hipertensión portal y la importancia de las várices esófago-gástricas como causa de hemorragia digestiva alta (10 por ciento). En la presente revisión se analiza la fisiopatología de la circulación hepática y la fisiopatología de la hipertensión portal. Se destaca que, a través del tiempo, alrededor del 25 a 30 por ciento de los cirróticos tienen hemorragia digestiva alta; que la mortalidad de cada episodio de sangramiento tiene una mortalidad de 30 a 50 por ciento y que las recurrencias se presentan en el 50 a 80 por ciento de los que sobreviven al primer episodio. Se recalca que no todos los sangramientos de los cirróticos se deben a ruptura de várices sino que a otras lesiones. En el manejo del cirrótico con hipertensión portal y várices esófago-gástricas deben considerarse tres problemas o situaciones: prevención del primer sangramiento: betabloqueadores. Tratamiento de la hemorragia misma: corrección de la hipovolemia y detención del sangramiento con: escleroterapia o ligadura endoscópica de las várices. En su defecto, comprensión con balones y/o vasopresina, glipresina o somatostatina o derivación porto-sistémica transyugular intrahepática. Prevención de las recurrencias: betabloqueo o permanencia o erradicación de las várices con ligadura o escleroterapia. En suma, se han hecho grandes avances en la prevención primaria y secundaria de la hemorragia digestiva por ruptura de várices esófago-gástricas, así como en el tratamiento de los episodios de sangramiento. Por el contrario, se ha hecho poco progreso en la prevención de la cirrosis de Laennec y del alcoholismo. En este campo los esfuerzos han sido muchos menores

Territórios venosos do fígado em natimortos de termo. Estudo anátomo-cirúrgico e sua importância nas hepatectomias parciais regradas / Venous sites of the liver in stilborn at term anatomicsurgical study and its importance in ruled partial hepatectomies

Foram selecionados 45 natimortos de termo, cujos fígados ao método de injeçäo e corrosäo para a obtençäo de "cats" vasculares, visando o estudo de seus territórios venosos. Em nosso estudo, pudemos observar que 31 natimortos (68,9 por cento) apresentaram um padräo de três segmentos; 12 (26,7 por cento), um padräo de quatro segmentos; e dois (4,4 por cento), um padräo de cinco segmentos. O conhecimento dos territórios venosos tem-se mostrado indispensável para a perfeita execuçäo da cirurgia resseccional hepática