Portal Vein Flow Research Articles

Importance of the temporary portocaval shunt during adult living donor liver transplantation

Adult living donor liver transplantation (aLDLT) is associated with surgical risks for the donor and with the possibility of small-for-size syndrome (SFSS) for the recipient, with both events being of great importance. An excessively small liver graft entails a relative increase in the portal blood flow during reperfusion, and this factor predisposes the recipient to an increased risk of SFSS in the postoperative period, although other causes related to recipient, graft, and technical factors have also been reported. A hemodynamic monitoring protocol was used for 45 consecutive aLDLT recipients. After various hemodynamic parameters before reperfusion were analyzed, a significant correlation between the temporary portocaval shunt flow during the anhepatic phase and the portal vein flow (PVF) after reperfusion of the graft (R(2) = 0.3, P < 0.001) was found, and so was a correlation between the native liver portal pressure and PVF after reperfusion (R(2) = 0.21, P = 0.007). The identification of patients at risk for excessive portal hyperflow will allow its modulation before reperfusion. This could favor the use of smaller grafts and ultimately lead to a reduction in donor complications because it would allow more limited hepatectomies to be performed.

Strategies for Successful Left-Lobe Living Donor Liver Transplantation in 250 Consecutive Adult Cases in a Single Center

Living donor liver transplantation (LDLT) using left-lobe grafts was not generally recognized as feasible due to the problem of graft size. We retrospectively evaluated strategies for successful left-lobe LDLT in 250 consecutive cases stratified into 2 eras: Era 1 (n = 121), in which surgical procedures were continually refined, and Era 2 (n = 129), in which established procedures were used. Graft volume (GV) did not affect the incidence of graft function or survival. Era 2 patients had decreased portal vein (PV) pressure at closure (16.0 ± 3.5 mmHg vs 19.1 ± 4.6 mmHg, p < 0.01), increased PV flow/GV (301 ± 125 mL/min/100g vs 391 ± 142 mL/min/100g, p < 0.01), and improved graft survival rate (1-year: 90.6% vs 81.8%. p < 0.01) despite the smaller GV/standard volume (SLV) ratio (36.2% ± 5.2% vs 41.2% ± 8.8%, p < 0.01) compared with Era 1. Patients in Era 2 had lower PV pressure and greater PV flow (y = 598-5.7 x, p = 0.02) at any GV/SLV compared with cases in Era 1 (y = 480-4.3 x, p < 0.01), representing greater graft compliance. Univariate analysis for graft survival showed that Era 1, Model for End-Stage Liver Disease (MELD) score ≥ 20, inpatient status, closing portal venous pressure ≥ 20 mmHg, no splenectomy, and operative blood loss ≥ 10 L were the risk factors for graft loss, and multivariate analysis showed that Era 1 was the only significant factor (p < 0.01). During Era 2, development of primary graft dysfunction was associated with inpatient recipient status (p = 0.02) and donor age ≥ 45 years (p < 0.01). The outcomes of left-lobe LDLT were improved by accumulated experience and technical developments.

Impact of mesocaval shunt on safe minimal liver remnant: Porcine model

To investigate the capacity of shunts to relieve portal hypertension and decrease the safe minimal liver remnant in pigs. A subtotal hepatectomy with < 60 mL blood loss and without hepatic pedicle occlusion was performed. The mesenteric venous inflow was diverted through a mesocaval shunt (MCS) constructed using the prepared left renal vein with an end-to-side running suture of 5-0 proline. All 21 animals that underwent subtotal hepatectomy and/or MCS were divided into three groups. In the 15% group, the residual volume was 14%-19% of total liver volume (TLV); in the 15%+ S group, the residual volume was also 14%-19% of TLV with a mesocaval shunt (MCS); and in the 10%+ S group, the residual volume was 8%-13% of TLV with an MCS. In the three groups, the intraoperative portal vein pressure (PVP) and portal vein flow (PVF) were monitored and compared at laparotomy and 1 h post-hepatectomy. The survival rate, sinusoidal endothelial damage, tissue analysis, and serum analysis were investigated among the three groups. The percentage residual liver volume was 15.9%, 16.1% and 11.8% in the 15%, 15%+ S, 10%+ S groups, respectively. After hepatectomy, PVF and portal-to-arterial flow ratio in the 15%+ S group significantly decreased and hepatic artery flow (HAF) per unit volume significantly increased, compared to those in the 15% group. The PVP in the 15%+ S group and 10%+ S group increased slightly from that measured at laparotomy; however, in the 15% group, the PVP increased immediately and significantly above that observed in the other two groups. The 14-d survival rates were 28.5%, 85.6%, and 14.2% in the 15%, 15%+ S, and 10%+ S groups, respectively. In the 15%+ S group, the shunts effectively attenuated injury to the sinusoidal endothelium, and the changes in the serum and tissue analysis results were significantly reduced compared to those in the 15% and 10%+ S groups. MCS can decompress the portal vein and so attenuate liver injury from hyperperfusion, and make extreme or marginal hepatectomy safer.

Cruveilhier-Baugarten syndrome: sonographic aspects

Objective: The purpose of this paper is to analyze the sonographic changes that characterize the Cruveilhier-Baumgarten syndrome and its clinical charactheristics. CruveilhierBaumgartem syndrome is characterized by a prominent paraumbilical vein, with dilatated superficial veins of the abdominal wall radiating from the umbilicus of patients with chronic liver disease and portal hypertension. Patients and methods: In a sonographic evaluation of 60 patients diagnosed with chronic liver disease with portal hypertension we found 4 cases of Cruveilhier-Baumgarten syndrome, which we studied with color doppler sonography. Results: All patients were male, in their third decade of life, with a clinical history of splenomegaly and varicose abdominal wall veins. Patients had schistosomiasis and micronodular cirrhosis on hystopathological examination. We also evaluated two patients with esophageal varices without hemathemesis. All patients had ultrasound signs of splenomegaly and chronic liver disease, with hepatopetal flow in all segments of the portal vein and hepatofugal flow in the efferent veins of the liver (paraumbilical vein in the falciform ligament and the anterior abdominal wall surface veins). Conclusion: CBS is charactherized by the association of signs of chronic liver damage with splenomegaly, distention of paraumbilical veins (portal hypertension) and blood flow towards the superficial abdominal wall veins, which are Cruveilhier-Baugarten syndrome: sonographic aspects Joao Paulo Kawaoka Matushita1, Jose de Laurentys-Medeiros2, Julieta Sebastiao Matushita3, Cristina Sebastiao Matushita4, Joao Paulo Kawaoka Matushita Jr.5 1 Professor Associado da Faculdade de Medicina da Universidade Federal de Minas Gerais. Medico Radiologista, CDI Dr. Matsushita Ltda. Belo Horizonte, MG – Brasil. 2 Professor Titular de Semiologia Medica da Faculdade de Ciencias Medicas de Belo Horizonte. Belo Horizonte, MG – Brasil. 3 Medica Radiologista. CDI Dr. Matsushita Ltda. Belo Horizonte, MG – Brasil. 4 Medica Nuclear. CDI Dr. Matsushita Ltda. Belo Horizonte, MG – Brasil. 5 Medico. Mestrando em Radiologia e Diagnostico por Imagem da Faculdade de Medicina da Universidade Federal do Rio de Janeiro-FM-UFRJ. Rio de Janeiro, RJ – Brasil. Sindrome de Cruveilhier-Baumgarten: aspectos ultrassonograficos DOI: 10.5935/2238-3182.20130010

Liver cirrhosis and portal hypertension in cystic fibrosis

As the expected survival improves in individuals with the cystic fibrosis (CF), so they may be faced with a number of medical complications. The aim of this study was to analyze the prevalence of liver cirrhosis in our CF population as well as the clinical and genetic characteristics of these patients. All patients older than 2 years (n = 96) were screened for liver disease. Liver cirrhosis was defined by ultrasonographic findings of distinct heterogeneity of liver parenchyma and nodular liver surface and/or by liver biopsy findings. Enlarged spleen, distended portal vein and abnormal portal venous flow indicated portal hypertension. Clinical and genotype data were analyzed. Sixteen patients were found to have liver cirrhosis, three of them with portal hypertension. All patients had pancreatic insufficiency. Nutritional status expressed as standard deviation score (Z score) for weight, height, and body mass index was as follows: zW = -0.40 +/- 1.24, zH = -0.83 +/- 1.02, and BMI = 20.1 +/- 2.3. CF patients with liver cirrhosis generally had mild-to-moderate lung disease, with average FVC and FEV1 values of 97.1 +/- 16.5% of predicted and 87.9 +/- 23.5% of predicted, respectively. Genetic analysis showed high frequency of F508del mutation in the group with cirrhosis (90.6%). The prevalence of liver cirrhosis in our CF population older than 2 years was 16.6%. Patients with pancreatic insufficiency and severe CFTR mutations, especially F508del, were exposed to higher risk of developing liver cirrhosis. Liver cirrhosis has no significant impact on the pulmonary function and the nutritional status, until the end-stage liver disease.

Ultrasound predictors of compensated liver cirrhosis in hemodialysis patients with hepatitis C

Ultrasound examination was performed in 80 hemodialysis (HD) patients with chronic hepatitis C in order to determine the ultrasound predictors of compensated liver cirrhosis. The ultrasound score (US) was calculated from the morphological parameters (liver size, morphology, surface, echogenicity and spleen volume) and the hemodynamic parameters (portal vein diameter and portal vein mean flow velocity). The US ranged from 0 to 200, with a cut-off value of 66, for discrimination between absence and presence of liver cirrhosis. A logistic regression model with stepwise variable selection was used to determine predictors of the progression of liver disease. According to the calculated US, patients were divided into two groups. The first group consisted of 37 (46.3%) patients with US greater than 66, indicating the presence of compensated liver cirrhosis. The second group included 43 (53.7%) patients without liver cirrhosis, with US equal to or less than 66. The value of liver morphology was significantly higher, but the portal vein flow velocity was significantly lower in patients with compensated liver cirrhosis compared with those without cirrhosis. Furthermore, rounded liver surfaces and increased liver echogenicity were significantly more frequent in patients with compensated liver cirrhosis compared with the non-compensated group. Logistic regression model with stepwise discriminant analysis identified liver morphology, liver echogenicity and portal vein mean flow velocity as independent ultrasound predictors of compensated liver cirrhosis in HD patients with chronic hepatitis C. Ultrasound examination could be used for non-invasive diagnosis of compensated liver cirrhosis, with accurate estimation of the disease severity in HD patients with chronic hepatitis C.

Extracorporeal continuous portal diversion plus temporal plasmapheresis for “small-for-size” syndrome

To investigate the effect of plasmapheresis via the portal vein for "small-for-size" syndrome (SFSS) aided by extracorporeal continuous portal diversion (ECPD). Extensive or total hepatectomy in the pig is usually adopted as a postoperative liver failure (PLF) or SFSS model. In this study, animals which underwent 85%-90% hepatectomy were randomized into either the Systemic group (n = 7) or the Portal group (n = 7). In the Systemic group, all pigs received temporal plasmapheresis (PP) via the extracorporeal catheter circuit (systemic to systemic circulation) from 24 to 30 h post-hepatectomy (PH); in the Portal group, all pigs received ECPD to divert partial portal vein flow (PVF) to the systemic circulation after hepatectomy, then converted to temporal PP from 24 to 30 h PH, and subsequently converted to ECPD again until 48 h PH. In the Portal group, the PVF was preserved at 3.0-3.3 times that of the baseline value, similar to that following 70% hepatectomy, which was regarded as the optimal PVF to the hypertrophic liver remnant. At 48 h PH, all pigs were re-opened and the portal vein pressure (PVP), PVF, and HAF (hepatic artery flow) were measured, and then diversion of the portal venous flow was terminated. After 1 h the PVP, PVF, and HAF were re-measured. The portal hemodynamic changes, liver injury, liver regeneration and bacterial/lipopolysaccharide (LPS) translocation were evaluated in the two groups. The PVP in the Portal group was significantly lower than that in the Systemic group during the time period from 2 to 49 h PH (P < 0.05). Serum alanine aminotransferase (ALT), total bilirubin (TB) and ammonia were significantly reduced in the Portal group compared with the Systemic group from 24 to 48 h PH (P < 0.05). The Portal group may have attenuated sinusoidal endothelial injury and decreased the level of HA compared with the Systemic group. In the Systemic group, there was significant sinusoidal dilation, hydropic changes in hepatocytes and hemorrhage into the hepatic parenchyma, and the sinusoidal endothelial lining was partially destroyed and detached into the sinusoidal space. CD₃₁ immunostaining revealed significant destruction of the endothelial lining. In the Portal group, there was no intraparenchymal hemorrhage and the sinusoidal endothelial cells and hepatocytes were well preserved. CD₃₁ immunostaining was mild which indicated less destruction of the endothelial lining. HA was significantly decreased in the Portal group compared with the Systemic group from 2 to 48 h PH. The rate of liver remnant regeneration was elevated, while apoptosis was attenuated in the Portal group compared with the Systemic group. Thymidine kinase activity was much higher in the Portal group than in the Systemic group at 48 h PH. The PCNA index was significantly increased and the apoptotic index was significantly decreased in the Portal group compared with the Systemic group. Bacterial translocation and endotoxin, as well as the inflammatory response, were significantly attenuated in the Portal group compared with the Systemic group. LPS, tumor necrosis factor-α and interleukin-6 levels were all significantly decreased in the Portal group compared with the Systemic group from 24 to 48 h PH, while bacterial DNA level was significantly decreased from 2 to 48 h PH. PP plus ECPD via the portal vein can attenuate toxic load and hyperperfusion injury, and should be undertaken instead of PP via the systemic circulation in SFSS or PLF.

A Case Report of Pancreatic Arteriovenous Malformation Diagnosed by Endoscopic Ultrasonography

Pancreatic arteriovenous malformations (AVMs) are rare, and most cases occur as congenital anomalies. Many patients with AVM are asymptomatic, but occasionally present with abdominal pain or gastrointestinal bleeding. The increased portal vein flow that forms these malformations can lead to portal hypertension and gastrointestinal bleeding in the absence of primary liver pathology. Early diagnosis can lead to successful surgical resection or percutaneous transarterial embolization. We report a case of a patient with pancreatic AVM in the tail of the pancreas, in which endoscopic ultrasonography was helpful. This patient presented with abdominal pain and was subsequently treated with distal pancreatectomy. (Korean J Med 2013;84:708-712)

MR-based Measurements of Portal Vein Flow and Liver Stiffness for Predicting Gastroesophageal Varices

We evaluated flow parameters measured by phase-contrast magnetic resonance (MR) imaging (PC-MRI) of the portal venous system and liver stiffness measured by MR elastography (MRE) to determine the usefulness of these methods in predicting gastroesophageal varices (GEV) in patients with chronic liver disease (CLD). In patients with CLD and controls, we performed PC-MRI on the portal (PV) and superior mesenteric veins; calculated mean velocity (V, cm/s), cross-sectional area (S, mm²), and flow volume (Q, mL/min); and determined markers of liver fibrosis (liver stiffness [kPa]) and aspartate aminotransferase (AST) platelet ratio index [APRI]). We visually assessed GEV and development of collateral pathways of the PV on routine contrast-enhanced dynamic MR imaging and compared patient characteristics, flow parameters, liver stiffness markers, and visual analysis among 3GEV groups, those with mild, severe, or no GEV with reference to endoscopic findings. Child-Pugh grade, VPV, SPV, liver stiffness, APRI, and visually identified GEV (visible GEV) differed significantly among the 3 groups (P<0.05). We investigated VPV, SPV, liver stiffness, and visible GEV as independent markers to distinguish patients with and without GEV and examined VPV and visible GEV to predict severe GEV. Visible GEV showed low sensitivity (14 to 30%) and high specificity (98%) for predicting GEV in patients with CLD. A subgroup analysis that excluded cases with collateral pathway demonstrated slightly improved diagnostic performance of VPV and liver stiffness. Portal vein flow parameters and liver stiffness can be useful markers for predicting GEV in patients with CLD.

Protocolo de monitorización hemodinámica hepática en el trasplante hepático de donante vivo en adultos

IntroductionThe recipient of an adult living donor liver transplant (ALDLT) is subjected to great haemodynamic changes that could lead to the appearance of a “small-for-size” syndrome in the post-operative period due to portal hyperflow. The aim of this article is to evaluate these changes, and try to correlate them with portal vein flow during reperfusion. Material and methodsA protocol for monitoring various liver haemodynamic data of the ALDLT recipient before, during and after surgery has been used since the year 2003. The haemodynamic outcome of the recipient after the transplant, as well as the correlation between the portal vein flow during reperfusion and the collected haemodynamic data is analysed. ResultsThere was no small for size syndrome. A significant relationship was found between the portal flow during reperfusion and the portal vein pressure at the beginning of the operation (r=0.46, P<.006) and with the portocaval shunt flow during the anhepatic phase (r=0.55, P<.001). The recipients showed a normal splanchnic hemodynamic state at 3 months after the transplant. ConclusionsHaemodynamic monitoring of the ALDLT recipient is essential to prevent portal hyperflow. The relationship between flow during reperfusion and flow through the portocaval shunt means that patients with a higher risk of hyperflow can be identified and can be modified before reperfusion.

In vivo validation of 4D flow MRI for assessing the hemodynamics of portal hypertension

To implement and validate in vivo radial 4D flow MRI for quantification of blood flow in the hepatic arterial, portal venous, and splanchnic vasculature of healthy volunteers and patients with portal hypertension. Seventeen patients with portal hypertension and seven subjects with no liver disease were included in this Health Insurance Portability and Accountability Act (HIPAA)-compliant and Institutional Review Board (IRB)-approved study. Exams were conducted at 3T using a 32-channel body coil with large volumetric coverage and 1.4 mm isotropic true spatial resolution. Using postprocessing software, cut-planes orthogonal to vessels were used to quantify flow (L/min) in the hepatic and splanchnic vasculature. Flow quantification was successful in all cases. Portal vein and supraceliac aorta flow demonstrated high variability among patients. Measurements were validated indirectly using internal consistency at three different locations within the portal vein (error = 4.2 ± 3.9%) and conservation of mass at the portal confluence (error = 5.9 ± 2.5%) and portal bifurcation (error = 5.8 ± 3.1%). This work demonstrates the feasibility of radial 4D flow MRI to quantify flow in the hepatic and splanchnic vasculature. Flow results agreed well with data reported in the literature, and conservation of mass provided indirect validation of flow quantification. Flow in patients with portal hypertensions demonstrated high variability, with patterns and magnitude consistent with the hyperdynamic state that commonly occurs in portal hypertension.

33. Feasibility study on hypothermic machine perfusion of human donor livers using a pressure controlled perfusion system: Initial results on single or dual-flow modalities

Hypothermic machine perfusion (HMP) has shown superior results to conventional cold storage method in kidney preservation. Similar promising results have been reported for HMP of livers in large animal models; however data from human livers remain scarce. The aims of this study is to establish a reproducible method of HMP of human livers using a pressure controlled system, to assess if sterility can be maintained throughout the procedure, and evaluate modes of perfusion (artery alone, portal vein alone, or both simultaneously). 16 human livers rejected for transplant by all UK centres with appropriate consent for research were randomised into four groups. Group 1: 7 h cold storage and 1 h HMP through hepatic artery (HA) alone ( n = 4). Group 2: 7 h cold storage and 1 h HMP through hepatic artery (HA) and portal vein (PV) ( n = 4). Group 3: 7 h cold storage and 1 h HMP through PV ( n = 4). Group 4: 8 h simple cold storage (CS). A pressure controlled system where flow is automatically adjusted according to resistance to maintain a constant pressure (7 mmHg for PV and 30 mmHg for HA) was used, based on the Lifeport kidney machine using Belzers KPS perfusate. Livers were perfused at 4–8 °C using KPS solution under sterile conditions. Perfusion parameters (pressure, flow, resistance and temperature) were recorded every 15 min. Perfusate samples for microbial culture and sensitivity were taken before and after the perfusion. HA pressure of 30 mmHg and PV pressure of 7 mmHg were maintained throughout the perfusion. HA and PV flow ranged from 11 to 107 ml/min (average 59.5 ml/min) and 39–199 ml/min (average 96.2 ml/min). HA and PV resistance ranged from 0.17 to 1.99 (average 0.71) and 0.07 to 0.17 mmHg/ml/min (average 0.08). Temperature was maintained between 4 and 8 °C using the supplied heat exchanger. Culture and sensitivity results from the perfusate showed that sterility was maintained throughout the procedure. Our technique proved to be a reliable and reproducible method of donor liver HMP. Resistance in HA was higher than in PV, while flow in the HA was less than the PV. Sterility could be maintained throughout the perfusion process. These data provide a basis for further evaluation of liver HMP as a method for preserving livers during clinical hepatic transplantation.

Splenomegaly Is a Risk Factor for Biliary and Artery Complications in Living Donor Liver Transplantation

Blood flow to the liver is maintained by hepatic arterial buffer response (HABR), which is an essential autoregulatory mechanism. Portal hyperperfusion impairs hepatic artery flow (HAF) due to the HABR, probably resulting in high incidence of biliary and artery complications in liver transplantation. The previous studies have reported that portal vein flow is directly correlated to the splenic volume. The aim of this study is to investigate the impact of preoperative splenomegaly, and assess the efficacy of portal modulation such as preoperative splenic artery embolization (SAE) or intraoperative splenic artery ligation (SAL) on biliary and artery complications after living donor liver transplantation (LDLT). From 2004 to 2011, 160 consecutive LDLT were retrospectively analyzed. Patients were divided into group 1 with splenomegaly (n= 128) and group 2 without splenomegaly (n=32). The overall biliary and artery complication rate was 43% (n=68) and 11% (n=17) respectively. The biliary complication rate was 48% (n=61) in group 1 and 22% (n=7) in group 2 (P=0.008). Biliary anastomotic stricture was seen in 54 patients(42%) in group 1, and 7 patients(22%) in group 2 (P=0.034), whereas biliary non anastomotic stricture was seen in 4 patients(3%) in group 1, and 0 patient in group 2 (P=0.311). 27 patients(20%) in group 1 and one patient(3%) in group 2 had early biliary stricture (≤90 days after LDLT) (P=0.024), on the other side, 33 patients(26%) in group 1 and six patients(19%) had late biliary stricture (>90 days after LDLT) (P=0.41). The artery complication rate was 13% in group 1 and 0% in group 2 (P=0.03). Hepatic arterial thrombosis (HAT) occurred in three (18%), and hepatic arterial stenosis (HAS) in four (23%), and splenic artery syndrome (SAS) in 10 patients (59%) each. The incidence of biliary complication, especially early biliary anastomotic stricture in group 1 was greater than in group 2. Similarly the incidence of artery complication was greater in group 1, and SAS was the most common artery complication in group 1. In a multivariate analysis, preoperative splenomegaly was an independent risk factor for both biliary and artery complications in LDLT. Of the 160 LDLT recipients, portal modulation such as preoperative SAE or intraoperative SAL was performed in 81. There was no significant difference in the incidence of biliary and artery complications between the patients who underwent portal modulation and those who didn‘t undergo portal modulation despite the rate of patients with splenomegaly was significantly higher in the patients who underwent portal modulation. In conclusion, preoperative splenomegaly is important to predict the risk of biliary and artery complication after LDLT. Recipient with Splenomegaly may have impaired HAF due to the HABR, resulting in high incidence of biliary and artery complications after liver transplantation. Portal modulation through preoperative SAE or intraoperative SAL may be effective in prevention of biliary and artery complications after LDLT through a decrease in portal hyperperfusion.

Ligation of Left Renal Vein for Spontaneous Splenorenal Shunt to Prevent Portal Hypoperfusion after Orthotopic Liver Transplantation: A Case Report

Low portal vein flow after orthotopic liver transplantation due to spontaneous splenorenal shunt is associated with hepatic hypoperfusion and poor allograft survival. We describe a case of recovered portal flow by ligation of the left renal vein on the first postoperative day after orthotopic liver transplantation of a 54-year-old female with alcoholic cirrhosis, chronic kidney failure and spontaneous splenorenal shunt. After reperfusion portal flows were extremely low, but because of severe coagulopathy and diffuse bleeding, ligation of the left renal vein was not attempted. A relaparotomy was performed on the first postoperative day and the left renal vein was ligated at its confluence to the inferior vena cava. Portal flows subsequently increased and the patient presented a good and stable liver function. We conclude, that patients with known preoperative splenorenal shunts should be closely monitored and if the portal flow becomes insufficient, ligation of the left renal vein should be attempted in order to optimize the portal perfusion of the liver.

Impact of localized ascites after pediatric living donor liver transplantation: report of three cases

Fluid collection is common after living donor liver transplantation (LDLT), and can include hematomas, bilomas, abscesses, and seromas. Although accumulated fluid rarely becomes infected and usually remains localized, localized ascites can sometimes be sufficiently extensive to induce vascular complications. This report presents three such cases in pediatric patients that underwent LDLT. A 33-month-old patient showed an increase in the volume of localized ascites around the hepatic vein anastomoses together with low hepatic vein flow on postoperative day (POD) 47. An 82-month-old patient showed an increase in the volume of localized ascites around the portal vein anastomoses together with low portal vein flow on POD 71. A 63-month-old patient showed an increase in the size of a localized abscess around the hepaticojejunostomy with dilatation of all of the intrahepatic bile ducts on POD 20. These cases illustrate the need for awareness of possible vascular or biliary complications due to compressive localized ascites after LDLT.

Effect of pre- and probiotics on liver regeneration after resection: a randomised, double-blind pilot study

Liver regeneration is a prerequisite for extended liver surgery. Several studies have shown that the bacterial gut flora is able to modulate liver function. Previously we observed that synbiotics could partly reverse the impaired mitosis rate of hepatocytes in a rat model of synchronous liver resection and colon anastomosis. The effect of synbiotics on liver function after hepatic resection has not been analysed yet. A prospective randomised double-blind pilot trial was undertaken in 19 patients scheduled for right hepatectomy. All patients received enteral nutrition immediately post-operatively. Comparison was made between a group receiving a combination of four probiotics and four fibres and a placebo group receiving the fibres only starting the day before surgery and continuing for 10 days. Primary study endpoint was the liver function capacity measured by 13C-methacetin breath test and indocyanine green plasma disappearance rate. Portal vein flow, liver volumetry, laboratory parameters for liver function, length of hospital stay, post-operative complications and side effects of synbiotic therapy were recorded. Liver function capacity was comparable in both groups. Complications had a negative impact on liver function. Because complications were more severe in the verum group, a sub-analysis was performed. In case of an uncomplicated course, liver function capacity was better in the patients with synbiotics. No severe side effects occurred. Synbiotics might be able to increase liver function capacity in patients after liver resection, but patient numbers were too small and the clinical courses too heterogeneous to draw any definite conclusions.

Portal Vein Aneurysm Presenting with Obstructive Jaundice

To the best of our knowledge, a portal vein aneurysm presenting with obstructive jaundice has not been reported in the literature. The preferred treatment for these aneurysms is surgical and a shunting procedure should be considered in cases with portal hypertension to preserve portal vein flow when portal hypertension is present or is secondary to the aneurysm itself. In our case, due to patient's advanced age and co-morbidities, an endoscopic biliary stent was placed which led to successful resolution of symptoms of obstructive jaundice.

Non‐cirrhotic portal hypertension in HIV mono‐infected patients

Unexplained liver injury including fibrosis and portal hypertension has rarely been reported among patients with HIV in the absence of co-infection with hepatitis B (HBV) or hepatitis C (HCV). We describe a series of HIV mono-infected patients with evidence of non-cirrhotic portal hypertension. HIV-infected patients with evidence of portal hypertension who were anti-HBV and anti-HCV negative and HBV and HCV RNA polymerase chain reaction (PCR) negative were identified from patients managed by the Victorian statewide HIV referral service located at The Alfred Hospital, Melbourne. Portal hypertension was defined as either radiological or endoscopic evidence of varices, portal vein flow obstruction, or elevated hepatic venous pressure gradient (HPVG). Five patients were found to have portal hypertension. These patients were male, aged 41 to 65 years, with known duration of HIV infection between 11 to 25 years. All had been treated with antiretroviral therapy, including didanosine. Tests for metabolic, autoimmune, and hereditary causes of liver disease failed to establish an etiology for the liver injury. All had radiological or endoscopic findings of varices, and four patients had radiological features of portal vein obstruction or flow reversal. Only one patient underwent HPVG measurement, which was elevated. Non-invasive fibrosis assessment revealed increased liver stiffness in three (out of four) patients, and no cirrhotic features were found on those who underwent liver biopsy. To our knowledge, this is the largest published series of non-cirrhotic portal hypertension in HIV mono-infected patients in Australia. Further research is needed to understand what relationship, if any, HIV or its treatments might have on liver injury over time.

Cold ischemia/reperfusion injury in a mouse model of partial liver transplantation

BackgroundInjury to partial liver grafts as a result of ischemia reperfusion remains an important factor in the outcome after transplantation in rodents. Although well described in rats, extended preservation has not been studied in a mouse model of partial liver transplantation. The aim of this study was to develop a model of cold ischemia/reperfusion injury in mouse partial liver transplantation. Materials and methodsPartial liver transplantation was performed in C57BL/6 mice. The liver grafts were stored in 4°C University of Wisconsin solution for different periods of preservation. The liver grafts were transplanted and reduced to 50% by removing the left lobe before the restoration of portal vein flow. Survival was monitored, and hepatocellular injury was examined by histopathologic staining. ResultsSurvival after partial liver transplantation was 100%, 88%, 89%, and 0% at 2 wk for cold preservation of 1, 4, 8, and 12 h, respectively. Histologic studies showed that microvascular and hepatocyte injury were limited in grafts with short preservation time (1, 4 h). Eight hours of cold ischemia led to focal necrosis. Twelve hours of storage resulted in liver graft failure in all recipients with histology showing extensive hepatic necrosis. ConclusionsThis study suggests partial liver transplantation can be performed in mice with satisfying graft survival. Increasing lengths of cold storage are associated with the progression of tissue injury and decreasing survival.

Effects of intravenous sulfide during resuscitated porcine hemorrhagic shock*

Controversial data are available on the effects of hydrogen sulfide during hemorrhage. Because the clinical significance of hydrogen sulfide administration in rodents may not be applicable to larger species, we tested the hypothesis whether intravenous Na2S (sulfide) would beneficially influence organ dysfunction during long-term, porcine hemorrhage and resuscitation. Prospective, controlled, randomized study. University animal research laboratory. Forty-five domestic pigs of either gender. Anesthetized and instrumented animals underwent 4 hrs of hemorrhage (removal of 40% of the blood volume and subsequent blood removal/retransfusion to maintain mean arterial pressure at 30 mm Hg). Sulfide infusion was started 2 hrs before hemorrhage, simultaneously with blood removal or at the beginning of retransfusion of shed blood, and continued for 12 hrs. Resuscitation comprised hydroxyethyl starch and norepinenephrine infusion titrated to maintain mean arterial pressure at preshock values. Before, immediately at the end of and 12 and 22 hrs after hemorrhage, we measured systemic and regional hemodynamics (portal vein, hepatic and right kidney artery ultrasound flow probes) and oxygen transport, nitric oxide and cytokine production (nitrate+nitrite, interleukin-6, tumor necrosis factor-α levels). Postmortem biopsies were analyzed for histomorphology (hematoxylin and eosin staining) and DNA damage (terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling staining). The progressive kidney (creatinine levels, creatinine clearance), liver (transaminase activities, bilirubin levels), and cardiocirculatory (norepipnehrine requirements, troponin I levels) dysfunction was attenuated in the simultaneous treatment group only, which coincided with reduced lung, liver, and kidney histological damage. Sulfide reduced mortality, however, irrespective of the timing of its administration. While the sulfide-induced protection against organ injury was only present when initiated simultaneously with blood removal, it was largely unrelated to hypothermia. The absence of sulfide-mediated protection in the pretreatment protocol may be due to the accumulation of sulfide during low flow states. In conclusion, sulfide treatment can be effective in hemorrhagic shock, but its effectiveness is restricted to a narrow timing and dosing window.