ACG Clinical Guideline: disorders of the hepatic and mesenteric circulation

Disorders of the mesenteric, portal, and hepatic veins and mesenteric and hepatic arteries have important clinical consequences and may lead to acute liver failure, chronic liver disease, noncirrhotic portal hypertension, cirrhosis, and hepatocellular carcinoma. Although literature in the field of vascular liver disorders is scant, these disorders are common in clinical practice, and general practitioners, gastroenterologists, and hepatologists may benefit from expert guidance and recommendations for management of these conditions. These guidelines represent the official practice recommendations of the American College of Gastroenterology. Key concept statements based on author expert opinion and review of literature and specific recommendations based on PICO/GRADE analysis have been developed to aid in the management of vascular liver disorders. These recommendations and guidelines should be tailored to individual patients and circumstances in routine clinical practice.

Mesenteric hypoperfusion and inflammation induced by brain death are not affected by inhibition of the autonomic storm in rats

OBJECTIVES: Brain death is typically followed by autonomic changes that lead to hemodynamic instability, which is likely associated with microcirculatory dysfunction and inflammation. We evaluated the role of the microcirculation in the hemodynamic and inflammatory events that occur after brain death and the effects of autonomic storm inhibition via thoracic epidural blockade on mesenteric microcirculatory changes and inflammatory responses. METHODS: Male Wistar rats were anesthetized and mechanically ventilated. Brain death was induced via intracranial balloon inflation. Bupivacaine (brain death-thoracic epidural blockade group) or saline (brain death group) infusion via an epidural catheter was initiated immediately before brain death induction. Sham-operated animals were used as controls (SH group). The mesenteric microcirculation was analyzed via intravital microscopy, and the expression of adhesion molecules was evaluated via immunohistochemistry 180 min after brain death induction. RESULTS: A significant difference in mean arterial pressure behavior was observed between the brain death-thoracic epidural blockade group and the other groups, indicating that the former group experienced autonomic storm inhibition. However, the proportion of perfused small vessels in the brain death-thoracic epidural blockade group was similar to or lower than that in the brain death and SH groups, respectively. The expression of intercellular adhesion molecule 1 was similar between the brain death-thoracic epidural blockade and brain death groups but was significantly lower in the SH group than in the other two groups. The number of migrating leukocytes in the perivascular tissue followed the same trend for all groups. CONCLUSIONS: Although thoracic epidural blockade effectively inhibited the autonomic storm, it did not affect mesenteric hypoperfusion or inflammation induced by brain death. .

Crohn's disease activity assessed by doppler sonography: the role of aortic flow parameters

OBJECTIVES: Intestinal neovascularization and abnormal abdominal arterial flow rates have been reported in Crohn's disease. The aim of this study was to evaluate Doppler sonography as a method for assessing Crohn's disease activity based on changes in splanchnic hemodynamics. METHODS: Forty-eight patients with Crohn's disease, 22 healthy volunteers and 12 patients with irritable bowel syndrome were evaluated by Doppler ultrasound for flow parameters of the aorta and superior mesenteric artery. This evaluation included the cross-sectional area, maximum flow volume, peak systolic velocity, end diastolic velocity, resistance and the pulsatility index. Disease activity was classified according to the Crohn's disease activity index. RESULTS: Most measurements in the aorta and superior mesenteric artery were significantly different between Crohn's disease patients and both control groups. Only the aortic maximum flow volume (CC = 0.37, p = 0.009) and aortic peak systolic velocity (CC = 0.30, p = 0.035) showed a significant positive correlation with the Crohn's disease activity index. The determination of cut-off points for the aortic maximum flow volume and peak systolic velocity measurements increased the sensitivity (80 and 75% for flow volume and velocity, respectively), specificity (57 and 75%), accuracy (67 and 75%) and positive (57 and 68%) and negative (80 and 81%) predictive values. These cut-off values permitted the correct classification of most of the patients with Crohn's disease with respect to disease activity. None of the superior mesenteric artery measurements were able to discriminate patients in relation to disease activity. CONCLUSION: The aortic maximum flow volume and peak systolic velocity levels estimated by Doppler sonography reflected disease activity in Crohn's disease. Doppler sonography of the aorta is therefore a novel noninvasive adjunct method that may be ...

Paradoxical effects of brain death and associated trauma on rat mesenteric microcirculation: an intravital microscopic study

OBJECTIVE: Experimental findings support clinical evidence that brain death impairs the viability of organs for transplantation, triggering hemodynamic, hormonal, and inflammatory responses. However, several of these events could be consequences of brain death-associated trauma. This study investigated microcirculatory alterations and systemic inflammatory markers in brain-dead rats and the influence of the associated trauma. METHOD: Brain death was induced using intracranial balloon inflation; sham-operated rats were trepanned only. After 30 or 180 min, the mesenteric microcirculation was observed using intravital microscopy. The expression of Pselectin and ICAM-1 on the endothelium was evaluated using immunohistochemistry. The serum cytokine, chemokine, and corticosterone levels were quantified using enzyme-linked immunosorbent assays. White blood cell counts were also determined. RESULTS: Brain death resulted in a decrease in the mesenteric perfusion to 30 percent, a 2.6-fold increase in the expression of ICAM-1 and leukocyte migration at the mesentery, a 70 percent reduction in the serum corticosterone level and pronounced leukopenia. Similar increases in the cytokine and chemokine levels were seen in the both the experimental and control animals. CONCLUSION: The data presented in this study suggest that brain death itself induces hypoperfusion in the mesenteric microcirculation that is associated with a pronounced reduction in the endogenous corticosterone level, thereby leading to increased local inflammation and organ dysfunction. These events are paradoxically associated with induced leukopenia after brain damage.

Ischemia-reperfusion histopathology alterations of the rabbit intestinal wall with and without exclusion of the collateral mesenteric circulation supply / Alterações histopatológicas da parede intestinal de coelhos na isquemia-reperfusão com e sem exclusão da circulação mesentérica colateral

PURPOSE: To evaluate the histopathology alterations of the intestinal mucosa of rabbits submitted to different times of mesenteric artery ischemia and reperfusion with and without celiac artery collateral circulation supply. METHODS: Two groups of eight male New Zealand white rabbits (weight 2.2-3.5 kg) were used in this study. In the Group 1 animals, the proximal mesenteric artery was occluded for 60 min with an atraumatic vascular clamp, followed by reperfusion for 60 min. In the Group 2 animals the small bowel and mesentery were cut 30cm and 60cm far from the gastroduodenal pyloric transition before the proximal mesenteric artery occlusion. Small bowel biopsies were obtained before ischemia (control), after 30 min and 60 min of mesenteric ischemia and at 30 and 60 min. of mesenteric artery reperfusion. RESULTS: In the Group I animals, the followings histopathology grade results were observed: t1, mean 0.4 + 0.29; t2, mean 1.9 ± 0.38; t3, 1.9 ± 0.33; t4, 1.2 ± 0.36 and t5, 1.2 ± 0.32. Differences between t0 and t2 and between t3 and t4 were statistically significant (p<0.05). Differences between t2 and t3 and t4 and t5 were not significant (p>0.5). In the Group II animals, it was observed: t1, mean 1.6 ± 0.33; t2, 2.4 ± 0.36; t3, 3.0 ± 0.35; t4 3.4 ± 0.31; t5, 3 ± 031. Differences between t0 and t1, t1 and t2, and t2 and t3 were significant (p<0.05). Differences between histopathology grades results of samples t1 to t5 in Group 1 and 2 were statistically significant (p<0.5). CONCLUSION: Microscopic examination of the biopsies revealed significant evidence of worse small bowel wall ischemia-reperfusion lesions by exclusion of the celiac artery collateral circulation supply.

OBJETIVO: Avaliar as alterações histopatológicas da mucosa intestinal de coelhos submetidos à isquemia-reperfusão com e sem exclusão da circulação mesentérica colateral. MÉTODOS: Foram estudados dois grupos de oito coelhos Nova Zelândia machos com pesos variáveis entre 2,2 e 3,5 kg de peso corpóreo. Nos animais do Grupo 1, a artéria mesentérica proximal foi ocluida por pinçamento atraumático durante 60 min, seguido de reperfusão por 60 min. No Grupo 2 o intestino delgado e o mesentério foram seccionados 30 cm e 60 após a transição pilórica gastroduodenal antes da oclusão da artéria mesentérica cranial. Biópsias da parede intestinal foram obtidas antes da isquemia (controle), após 30 e 60 min. de isquemia. RESULTADOS: No Grupo I foram observados os seguintes graus de lesões: t1,média de 0.4 + 0.29; t2, média 1.9 ± 0.38; t3, 1.9 ± 0.33; t4, 1.2 ± 0.36 e t5, 1.2 ± 0.32. As diferenças entre t0 e t2 e entre t3 e t4 foram significantes (p<0.05). As diferenças entre t2 e t3 e t4 e t5 não foram significantes (p>0.5). No Group II observou-se: t1, média de 1.6 ± 0.33; t2, 2.4 ± 0.36; t3, 3.0 ± 0.35; t4 3.4 ± 0.31; t5, 3 ± 031. As diferenças entre t0 e t1, t1 e t2, e t2 e t3 foram significantes (p<0.05). As diferenças entre os resultados histopatológicos das biopsies de t1 a t5 dos Grupos 1 e 2 foram significantes (p<0.5). CONCLUSÃO: A exclusão da circulação mesentérica colateral agravou significantemente a degeneração histopatológica na isquemia-reperfusão da parede intestinal.

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.

Systemic evaluation on ischemia and reperfusion injury of splanchnic organs in rats / Alterações sistêmicas na isquemia e reperfusão de órgãos esplâncnicos em ratos

PURPOSE: To evaluate hemodynamic and systemic changes during and after splanchnic ischemia and reperfusion (I/R). METHODS: Rats were divided into two groups: a) control: animals submitted to surgery, but not to I/R, treated with saline (5 ml/kg/h) for 150 min; b) group I/R: animals continuously infused with saline, and submitted to occlusion of the celiac trunk, superior mesenteric artery (SMA), and inferior mesenteric artery for 30 min, followed by a 120-min reperfusion. Mean arterial blood pressure (MABP), venous pressure, aortic and SMA blood flow, heart rate, esophageal temperature and hematocrit were evaluated. RESULTS: During reperfusion in I/R groups, there was a progressive decrease in MABP, aortic blood flow, SMA blood flow, heart rate and esophageal temperature; vein pressure and hematocrit remained unchanged during the experiment. CONCLUSION: The model of ischemia used causes systemic changes, which are evidenced by hypotension, decrease in mesenteric blood flow, heart rate and esophageal temperature.

OBJETIVO: Avaliar as alterações hemodinâmicas e sistêmicas decorrentes de isquemia e reperfusão (I/R) esplâncnica em ratos. MÉTODOS: Vinte ratos foram divididos em dois grupos: grupo controle: os animais foram submetidos à cirurgia, mas não a I/R e foram tratados com solução fisiológica (5 ml/kg/h) por 150 minutos; grupo I/R: os animais foram submetidos à administração contínua de solução fisiológica e à oclusão do tronco celíaco, artéria mesentérica superior e artéria mesentérica inferior por 30 minutos, seguidos por 120 minutos de reperfusão. Avaliou-se a pressão arterial média, pressão venosa, fluxo sangüíneo na aorta e na artéria mesentérica superior, freqüência cardíaca, temperatura esofágica e hematócrito. RESULTADOS: Durante a reperfusão, no grupo I/R, houve uma diminuição progressiva da pressão arterial média, fluxo sangüíneo na aorta e artéria mesentérica superior, freqüência cardíaca e temperatura esofágica; pressão venosa e hematócrito não sofreram alteração. CONCLUSÃO: O modelo de isquemia provocado por oclusão da artéria mesentérica superior, artéria mesentérica inferior e tronco celíaco por 30 minutos seguidos por 120 minutos de reperfusão provoca alterações sistêmicas evidenciadas por hipotensão, diminuição do fluxo sangüíneo mesentérico, da freqüência cardíaca e da temperatura esofágica.

Effects of different peep levels on mesenteric leukocyte-endothelial interactions in rats during mechanical ventilation

INTRODUCTION: Mechanical ventilation with positive end expiratory pressure (PEEP) improves oxygenation and treats acute pulmonary failure. However, increased intrathoracic pressure may cause regional blood flow alterations that may contribute to mesenteric ischemia and gastrointestinal failure. We investigated the effects of different PEEP levels on mesenteric leukocyte-endothelial interactions. METHODS: Forty-four male Wistar rats were initially anesthetized (Pentobarbital I.P. 50mg/kg) and randomly assigned to one of the following groups: 1) NAIVE (only anesthesia; n=9), 2) PEEP 0 (PEEP of 0 cmH2O, n=13), 3) PEEP 5 (PEEP of 5 cmH2O, n=12), and 4) PEEP 10 (PEEP of 10 cmH2O, n=13). Positive end expiratory pressure groups were tracheostomized and mechanically ventilated with a tidal volume of 10 mL/kg, respiratory rate of 70 rpm, and inspired oxygen fraction of 1. Animals were maintained under isoflurane anesthesia. After two hours, laparotomy was performed, and leukocyte-endothelial interactions were evaluated by intravital microscopy. RESULTS: No significant changes were observed in mean arterial blood pressure among groups during the study. Tracheal peak pressure was smaller in PEEP 5 compared with PEEP 0 and PEEP 10 groups (11, 15, and 16 cmH2O, respectively; p<0.05). After two hours of MV, there were no differences among NAIVE, PEEP 0 and PEEP 5 groups in the number of rollers (118±9,127±14 and 147±26 cells/10minutes, respectively), adherent leukocytes (3±1,3±1 and 4±2 cells/100µm venule length, respectively), and migrated leukocytes (2±1,2±1 and 2±1 cells/5,000µm², respectively) at the mesentery. However, the PEEP 10 group exhibited an increase in the number of rolling, adherent and migrated leukocytes (188±15 cells / 10 min, 8±1 cells / 100 µm and 12±1 cells / 5,000 µm², respectively; p<0.05). CONCLUSIONS: High intrathoracic pressure was harmful to mesenteric microcirculation in the experimental model of rats with normal lungs and ...

Acid-base disarrangement and gastric intramucosal acidosis predict outcome from major trauma / Desarranjo ácido-base e acidose gástrica intramucosal predizem desfecho de trauma grave

INTRODUCTION: This prospective non-interventional study intended to assess the prognostic value of gastric intramucosal acidosis in patients with severe trauma admitted to a medical/surgical ICU. METHODS: Gastric tonometer catheters were introduced to measure air PCO2 level (Tonocap device) in forty consecutive critically ill trauma patients. Gastric intramucosal pH, air PCO2 gradient, lactate and acid-base parameters were measured at admission and at 6, 12 and 24 h thereafter. RESULTS: The median age, mean APACHE II and SOFA scores were higher in nonsurvivors than in survivors (p<0.05). There were significant differences in the PCO2 gradient between survivors and nonsurvivors at 12 and 24 hours (10±7 vs. 24±19 mmHg, 13±16 vs. 29±25 mmHg; p<0.05). Gastric intramucosal pH values were lower in nonsurvivors than in survivors, on admission and after 12 or 24 hours (p<0.05). Arterial pH and bicarbonate were lower, lactate concentration higher, and base excess more negative in nonsurvivors. Prediction of outcome (mortality and MODS) at 24 hours of ICU assessed by their ROC curves was similar (p=NS). At 24 hours, air PCO2 gradient > 18 mmHg carried a relative risk of 4.6 for death, slightly higher than a HCO3 <20 mEq/L (RR=4.29) or base excess of <-2 mmol/L (RR=3.65). CONCLUSION: Bicarbonate, base deficit, lactate, gastric intramucosal pH and PCO2 gradient discriminate survivors from nonsurvivors of major trauma. A critical air PCO2 gradient carried the greatest relative risk for death at 24 hours of ICU. Inadequate regional blood flow as detected by a critical PCO2 gradient seems to contribute to morbidity and mortality of severe trauma patients.

INTRODUÇÃO: O objetivo deste estudo prospectivo, não-intervencionista, foi avaliar o valor prognóstico da acidose gástrica intramucosal em pacientes com trauma grave admitidos numa UTI. MÉTODOS: Cateteres tonométricos gástricos foram introduzidos para medir o nível de PCO2 aéreo em 40 pacientes traumatizados. O pH gástrico intramucosal, o gradiente de PCO2 aéreo, o lactato e os parâmetros ácido-base foram medidos na admissão e 6, 12 e 24 h após a admissão. RESULTADOS: A idade mediana, o APACHE II e os escores SOFA médios foram maiores nos não-sobreviventes que nos sobreviventes (p<0.05). Não houve diferenças significativas para o gradiente de PCO2 entre sobreviventes e não-sobreviventes após 12 e 24 horas (10±7 vs. 24±19 mmHg, 13±16 vs. 29±25 mmHg; P<0.05). Os valores de pH gástrico intramucosal foram menores nos não-sobreviventes que nos sobreviventes na admissão e após 12 ou 24 horas (P<0.05). O pH arterial e o bicarbonato foram menores, a concentração de lactato maior, o excesso de base mais negativo nos não-sobreviventes. Predição do desfecho (mortalidade e FMOS) nas 24 horas de UTI acessada pelas curvas ROC foi similar (p=NS). Nas 24 horas, um gradiente de PCO2 aéreo >18 mmHg acarretou um risco relativo de 4.6 para óbito, um pouco maior que um HCO3 <20 mEq/L (RR=4.29) ou um excesso de base <-2 mmol/L (RR=3.65). CONCLUSÃO: Bicarbonato, déficit de base, lactato, pH gástrico intramucosal e o gradiente de PCO2 discriminaram os sobreviventes dos não-sobreviventes de trauma. Um gradiente crítico de PCO2 aéreo acarretou o maior risco relativo para óbito após 24 horas de UTI. Fluxo sangüíneo regional inadequado detectado por um gradiente crítico de PCO2 parece contribuir para a morbidade e mortalidade de pacientes traumatizados graves.

Low hematocrit impairs gastric mucosal CO2 removal during experimental severe normovolemic hemodilution

OBJECTIVE: The net effects of acute normovolemic hemodilution with different hemoglobin levels on splanchnic perfusion have not been elucidated. The hypothesis that during moderate and severe normovolemic hemodilution, systemic and splanchnic hemodynamic parameters, oxygen-derived variables, and biochemical markers of anaerobic metabolism do not reflect the adequacy of gastric mucosa, was tested in this study. METHODS: Twenty one anesthetized mongrel dogs (16 ± 1 kg) were randomized to controls (CT, n = 7, no hemodilution), moderate hemodilution (hematocrit 2 5 percent ± 3 percent, n = 7) or severe hemodilution (severe hemodilution, hematocrit 15 percent ± 3 percent, n = 7), through an isovolemic exchange of whole blood and 6 percent hydroxyethyl starch, at a 20 mL/min rate, to the target hematocrit. The animals were followed for 120 min after hemodilution. Cardiac output (CO, L/min), portal vein blood flow (PVF, mL/min), portal vein-arterial and gastric mucosa-arterial CO2 gradients (PV-artCO2 and PCO2 gap, mm Hg, respectively) were measured throughout the experiment. RESULTS: Exchange blood volumes were 33.9 ± 3.3 and 61.5 ± 5.8 mL/kg for moderate hemodilution and severe hemodilution, respectively. Arterial pressure and systemic and regional lactate levels remained stable in all groups. There were initial increases in cardiac output and portal vein blood flow in both moderate hemodilution and severe hemodilution; systemic and regional oxygen consumption remained stable largely due to increases in oxygen extraction rate. There was a significant increase in the PCO2-gap value only in severe hemodilution animals. CONCLUSION: Global and regional hemodynamic stability were maintained after moderate and severe hemodilution. However, a very low hematocrit induced gastric mucosal acidosis, suggesting that gastric mucosal CO2 monitoring may be useful during major surgery or following trauma.

OBJETIVO: Os efeitos da hemodiluição normovolêmica com diferentes níveis de hemoglobina na perfusão esplâncnica são pouco conhecidos. Testamos a hipótese que durante a hemodiluição moderada e acentuada, os parâmetros hemodinâmicos sistêmicos e regionais e as variáveis relacionadas ao metabolismo de oxigênio não refletem a adequação da perfusão da mucosa gástrica. MÉTODOS: Vinte e um cães anestesiados com fentanil e vecurônio (16±1 kg) foram randomizados como controles (CT, n=7, sem hemodiluição normovolêmica), hemodiluição normovolêmica moderada (Ht 25±3 por cento, n=7) ou hemodiluição normovolêmica acentuada (Ht 15±3 por cento, n=7), pela troca isovolêmica entre o sangue total e hidroxietil amido a 6 por cento, 20 mL/min até o hematócrito pré-estabelecido para cada grupo. Os animais foram acompanhados por 120 min após a hemodiluição normovolêmica. Durante todo o experimento foram medidos o débito cardíaco (CO, L/min), o fluxo de veia porta (PVF, mL/min), e os gradientes de CO2 veia porta-arterial e mucosa gástrica-arterial (PV-artCO2 and PCO2-gap, mmHg, respectivamente). RESULTADOS: O volume de sangue trocado foi de 33,9±3,3 mL/kg para hemodiluição normovolêmica moderada e de 61,5±5,8 mL/kg para a hemodiluição normovolêmica acentuada. A pressão arterial e os níveis de lactato sistêmico e regional permaneceram estáveis em todos os grupos. Houve aumentos iniciais de débito cardíaco e de fluxo de veia porta, tanto na hemodiluição normovolêmica moderada quanto na hemodiluição normovolêmica acentuada; o consumo de oxigênio sistêmico e regional permaneceram estáveis, principalmente por conta de aumentos na taxa de extração de oxigênio. O PCO2-gap apresentou aumento significativo apenas nos animais submetidos a hemodiluição normovolêmica acentuada. CONCLUSÃO: Ocorre estabilidade hemodinâmica global e regional tanto na hemodiluição normovolêmica moderada quanto na acentuada. Entretanto, o hematócrito de 15 por cento induziu acidose moderada de mucosa gástrica, o que pode ser relevante em procedimentos cirúrgicos de grande porte ou no trauma.

Management of visceral artery aneurysms

Objective: Visceral artery aneurysms, despite being uncommon, are important vascular diseases, since they frequently are life threatening, and often fatal emergencies. The purpose of this study is to review our experience with treatment of visceral artery aneurysms. Method: Between 1988 and June, 2004, 37 visceral artery aneurysms were treated in 35 patients (17 male and 18 female) with average age of 56 mais ou menos 14 years. The most common locations were the splenic artery (18), the hepatic artery (10) and the superior mesenteric artery (four), 22 patients were asymptomatic, 13 patients were symptomatic. Emergency surgery was performed on three patients, elective open surgery on 20 patients, and endovascular treatment onseven patients. Results: Perioperative mortality rate was 3,1 por cento in the surgical group. The perioperative mobidity rate was 5,7 por cento: one case of respiratory distress and one case of bilious fistula were...

Mesenteric ischemia and portal hypertension caused by splenic arteriovenous fistula.

Splenic arteriovenous fistula is rare and usually presents with features of established portal hypertension (PHT). Presentation as acute mesenteric ischemia with features of acute PHT is uncommon. We report a 35-year-old lady who presented with severe abdominal pain, diarrhea and ascites, which was found to result from mesenteric ischemia and acute PHT secondary to splenic arteriovenous fistula. She underwent resection of fistula, which resulted in complete symptom relief.

Extracranial head and neck circulation aneurysms in a case of polyarteritis nodosa.

Polyarteritis nodosa (PAN) is a rare systemic necrotising medium vessel vasculitis. The hallmark of this condition is aneurysms which are seen in visceral arteries. Aneurysms of extracranial neck and head vessels are rare. We describe a case of PAN who had such aneurysms together with characteristic aneurysms in the mesenteric circulation.

Hepatorenal syndrome.

Hepatorenal syndrome is a life-threatening complication occurring commonly in cirrhosis liver and rarely in acute liver failure. It can be precipitated by shock, infection, surgery, large volume paracentesis or nephrotoxic drugs. Type I hepatorenal syndrome which usually develops over acute liver failure is rapidly progressive and has poor outcome. Type II hepatorenal syndrome is usually associated with refractory ascites and is slowly progressive with relatively good prognosis. Peripheral vasodilation with intrarenal vasoconstriction is the main pathophysiologic change. Diagnostic criteria, ascertained by international ascites club, is helpful to reach at a proper diagnosis. Management includes pharmacologic therapy to induce splanchnic vasoconstriction which improve renal circulation. Dopamine, vasopressin analogs (ornipressin and terlipressin), midodrine, noradrenaline have been used mainly as a bridge to the liver transplant or in anticipation of improvement in hepatic function. The molecular adsorbent recycling system (MARS) have been recently used in patients with hepatorenal syndrome. Transjugular intrahepatic portosystemic shunt is also another modality which has been used as a bridge to liver transplant in such patients.

Increased expression of endothelin receptors in human cirrhosis--relationship with splanchnic hemodynamics / 华中科技大学学报（医学）（英德文版）

The purpose of the present study was to assess the correlation that likely exists among increased portal pressure (Pp), portal blood flow quantity (Qp) and ETA and ETB receptor mRNA expression in human cirrhosis. In situ hybridization and reverse-transcription polymerase chain reactions (RT-PCR) were performed to determined the expression of ETA and ETB receptor mRNA in liver tissues from traumatic subjects (n = 10) and cirrhotic patients (n = 15) in whom hepatic hemodynamic values were measured. The expression of the two transcripts was significantly higher in liver samples of cirrhotic patients than in those obtained from traumatic subjects. It has shown that ETA receptor mRNA predominantly located in hepatic stellate cells (HSCs) and vascular smooth muscle cells of intrahepatic arteries and portal veins, ETB receptor mRNA in HSCs, sinusoidal endothelial cells and Kuppfer cells. There was a highly significant direct relationship between ETA and ETB receptor mRNA and Pp and Qp in cirrhotic patients. It suggests that liver paracrine endothelin system may be overactivated in human cirrhosis accompanied with increased expression of ETA and ETB receptor mRNA which may play an important role in the pathogenesis and maintenance of splanchnic hyperdynamics.

Insuficienca vascular mesentérica / Insufficiency vascular mesenteric

Justificación y objetivos: La isquemia mesentérica aguda es una de las emergencias gastrointestinales más graves y de peor pronóstico que el cirujano debe afrontar. En Estados Unidos la enfermedad isquémica intestinal se presenta en uno de cada mil ingresos hospitalarios, con una mortalidad entre 60 por ciento y 90 por ciento. Dada la importancia del problema se intenta hacer una descripción de la presentación clínica, diagnóstico, tratamiento y evolución de la patología isquémica intestinal en el factor predisponente más frecuente. En el 66 por ciento de los casos, el diagnóstico se estableció antes de las 12 horas del ingreso mediante laparotomía exploratoria, la tasa de mortalidad en general alcanzó el 81 por ciento. Se encontró una clara subutilización de adecuados estudios imagenológicos para llegar al diagnóstico, siendo la laparotomía una forma tardía de identificación, para realizar un tratamiento oportuno.

Cateterización venosa suprahepática en cuatro casos de shock séptico severo / Suprahepatic vein oxygen saturation monitoring and gastric tonometry in the management of severe septic shock: report of 4 cases

Splanchnic hypoperfusion, with pathogenic implications for multiple organ failure, can occur during septic shock. We report four patients with septic shock in whom regional hepatosplenic splanchnic perfusion was monitored through suprahepatic vein catheterization and gastric tonometry. Suprahepatic lactate and oxygen saturation showed splanchnic hypoperfusion in all patients. These parameters improved only in the patient that survived. Gastric tonometry was more inconsistent. We conclude that suprahepatic vein catheterization could have a role in the management of septic shock

Ecotomografía Doppler duplex mesentérico: revisión bibliográfica / Doppler duplex ultrasound in mesentery: review

A review of Doppler-duplex ultrasound in the evaluation of splachnic arteries is presented. Emphasis is made on the study in pre and postprandial examination. A detailed description of the scanning technique is made

La dexametasona, un inhibidor de la expresion de la oxido nitrico sintasa inducible, no modifica el estado hiperdinamico en ratas cirroticas / Dexamethasone, an inhibitor of the expression of the inducible nitric oxide synthase, does not modify the hyperdynamic state in cirrhotic rats

El aumento de la producción de óxido nítrico juega un papel importante en la fisiopatología de la cir- culación hiperdinámica asociada a la hipertensión portal. El probable mecanismo por el cual se produce este aumento no se encuentra aún bien definido. Con el objetivo de evaluar si la isoforma inducible es la responsable de estos cambios hemodinámicos, hemos estudiado el efecto de la administración de dexametasona, un inhibidor de la expresión de la óxido nítrico sintasa II, en ratas cirróticas tras la ligadura y sección del colédoco. Se determinaron los diferentes parámetros hemodinámicos sistémicos y esplácnicos, mediante la técnica de microesferas radiactivas, luego de la administración de dexametasona (3 mg/kg/día durante 3 días, ip) o su vehículo. En los animales cirróticos el efecto glucocorticoideo se puso de manifiesto a través de una disminución significativa en la ganancia de peso corporal y un moderado aumento, pero no significativo, de la presión arterial media. La administración de dexametasona no se asoció a cambios significativos de la resistencia vascular sistémica y esplácnica como así tampoco del flujo sanguíneo portal y presión portal. Similares resultados se observaron en el grupo de animales utilizados como controles. Se detectaron niveles significativamente más elevados de endotoxina en sangre portal y sistémica en 5 de 6 animales cirróticos. Nuestros resultados muestran que la administración de dexametasona no modifica los parámetros hemodinámicos sistémicos y esplácnicos en ratas cirróticas y endotoxémicas sugiriendo que la estimulación de la sintasa inducible no juega un papel importante en el aumento de la síntesis de óxido nítrico en la cirrosis.