Portal Venous Flow Research Articles

The effects of exercise on portal venous system in splenectomized adults

This study was designed to assess the effects of exercise on the portal venous system in splenectomized adults. Splenectomy is a surgical intervention commonly performed at surgery clinics and recognized as a cause of portal vein thrombosis. Intensive exercise increases blood flow to the contracting muscles, causes hypercoagulability and vasoconstriction in the splanchnic area, hence the portal vein diameter, blood flow velocity and discharge decrease. Forty adults participated in this investigation. Subjects were trained to run for twenty minutes on a treadmill at a velocity of 6 km/h and ten-degree elevation. We compared the white blood cell count, portal vein diameter, portal venous blood flow velocity and discharge of splenectomized and healthy adults before and after exercise. After exercise, the blood leukocyte count was significantly increased and the portal vein diameter was significantly reduced in both groups (p<0.001) but there were no statistically significant differences between the two groups. The portal venous blood flow rate in splenectomy group were significantly lower than in the control group (p<0.001). Furthermore the portal venous blood flow rates in both groups were significantly reduced after exercise (p<0.001). Exercise in splenectomized individuals can cause serious problems in form of decreasing splanchnic flow and increasing blood viscosity. After splenectomy, both healthy individuals and patients with hematologic diseases ought to avoid intensive exercises (Tab. 2, Ref. 16).

The responses of the hepatic and splanchnic vascular beds to vasopressin in rats

Vasopressin, a vasoactive peptide, causes vasoconstriction via V1a vasopressin receptors. Unlike other vasoconstrictor agents, vasopressin also has vasodilatory properties. The purpose of this study was to determine the effect of vasopressin on hepatic and splanchnic circulation in Sprague- Dawley rats. The experiments were conducted in not only isolated blood- and constant flowperfused livers but also anesthetized spontaneously breathing rats. In anesthetized rats, portal venous pressure (Ppv), systemic arterial pressure (Psa), central venous pressure, and hepatic blood flow (HBF) of combined portal venous and hepatic arterial blood flow were continuously measured, and splanchnic vascular bed resistance (Rspl) defined by (Psa - Ppv) / HBF was determined. In perfused livers, vasopressin at 0.1-1,000 nM caused weak venoconstriction as evidenced by small increase in Ppv. In anesthetized rats, when vasopressin was injected into the portal vein as a bolus consecutively at 0.01-100 nmol/kg, Psa increased dose-dependently with the peak increment of 60 ± 18 mmHg at 100 nmol/kg. Ppv and HBF decreased, with resultant increase in Rspl, indicating splanchnic vasoconstriction. In conclusion, hepatic venoconstrictor action of vasopressin was weak in rats. Vasopressin causes splanchnic vasoconstriction, resulting in a decrease in HBF and Ppv in anesthetized rats.

Wilson Disease: Canadian Perspectives on Presentation And Outcomes from an Adult Ambulatory Setting

Wilson disease (WD) is a rare disorder of copper metabolism. To describe the authors' clinical experience with a cohort of 48 adult patients followed in an ambulatory setting. A retrospective chart review of patients with a diagnosis of WD was performed. Fifty-nine charts were identified and 11 were excluded on further review. At diagnosis, 14 patients were asymptomatic, with 13 hepatic, 15 neurological and six mixed hepatic⁄neurological presentations. Ceruloplasmin levels were low (<0.20 g⁄L) in 94%, and 24 h urinary copper levels high (>0.60 µmol⁄L) in 95% of cases. D-penicillamine was the most common initial therapy (48%), with zinc the most common at review (65%). Overall, biopsy and ultrasound reports documented cirrhosis in 53%. Portal hypertension, defined as splenomegaly (>12.0 cm), reversed portal venous flow on ultrasound or varices⁄gastropathy on endoscopy was seen in 63%. At last review, 39% had elevated aspartate aminotransferase (>34 U⁄L) and⁄or alanine aminotransferase levels (>40 U⁄L). One death and one transplant occurred, while three patients had encephalopathy, two became jaundiced, two developed ascites and one experienced variceal bleed. Of 21 neurological presenting patients, 14 improved compared with baseline, with four making almost complete recovery. Eleven patients experienced documented episodes of neurological decline, including four with non-neurological presentation. Diagnostic magnetic resonance imaging showed basal ganglia (64%), brainstem (64%) abnormalities and atrophy (36%); follow-up showed basal ganglia lesions (50%) and atrophy (55%). WD is a diverse chronic disease with generally favourable outcomes for patients who respond to initial therapy, which can be managed predominantly in an ambulatory setting.

Orthotopic Liver Transplantation: Reversible Doppler US Findings in the Immediate Postoperative Period

Orthotopic liver transplantation (OLT) is the only definitive treatment for irreversible acute liver failure and chronic liver disease. In the immediate postoperative period after OLT, patients are closely monitored with Doppler ultrasonography (US) to detect treatable vascular complications and ensure graft survival. The first postoperative Doppler US examination is performed fairly early on the first postoperative day, before surgical wound closure has been performed. The immediate postoperative images, obtained when the effects of surgery are very recent, often reveal an array of findings that may appear alarming but that tend to normalize within a few days and are compatible with changes related to the surgery itself. These findings include a starry-sky appearance of reperfusion hepatic edema, transient foci of increased echogenicity, pneumobilia, small fluid collections, perihepatic hematomas, pleural effusion, temporary elevation of hepatic arterial velocity, transient elevation of resistive index (RI), decreased RI with tardus parvus waveform, increased portal venous flow and mono- or biphasic waveforms of the hepatic veins. Most of these changes revert to normal in the first postoperative week; deterioration atypical of transient changes requires further evaluation.

Percutaneous Transsplenic Access to the Portal Vein for Management of Vascular Complication in Patients with Chronic Liver Disease

To evaluate the safety and feasibility of percutaneous transsplenic access to the portal vein for management of vascular complication in patients with chronic liver diseases. Between Sept 2009 and April 2011, percutaneous transsplenic access to the portal vein was attempted in nine patients with chronic liver disease. Splenic vein puncture was performed under ultrasonographic guidance with a Chiba needle, followed by introduction of a 4 to 9F sheath. Four patients with hematemesis or hematochezia underwent variceal embolization. Another two patients underwent portosystemic shunt embolization in order to improve portal venous blood flow. Portal vein recanalization was attempted in three patients with a transplanted liver. The percutaneous transsplenic access site was closed using coils and glue. Percutaneous transsplenic splenic vein catheterization was performed successfully in all patients. Gastric or jejunal varix embolization with glue and lipiodol mixture was performed successfully in four patients. In two patients with a massive portosystemic shunt, embolization of the shunting vessel with a vascular plug, microcoils, glue, and lipiodol mixture was achieved successfully. Portal vein recanalization was attempted in three patients with a transplanted liver; however, only one patient was treated successfully. Complete closure of the percutaneous transsplenic tract was achieved using coils and glue without bleeding complication in all patients. Percutaneous transsplenic access to the portal vein can be an alternative route for portography and further endovascular management in patients for whom conventional approaches are difficult or impossible.

Effect of transjugular intrahepatic portosystemic shunt on glycometabolism in cirrhosis patients

Patients with liver cirrhosis suffer from hyperinsulinemia, hyperglucagonemia and a certain degree of insulin resistance, and portosystemic shunts may be involved in the etiology. A transjugular intrahepatic portosystemic shunt (TIPS) as a treatment for the complications of portal hypertension leads to hemodynamic changes. The objective of the present study is to evaluate whether TIPS can also affect glycometabolism in cirrhosis patients. Forty-six liver cirrhosis patients (experimental group [EG]) without diabetes who underwent TIPS were evaluated. Portal venous pressure (PVP), cardiac output (CO) and blood flow in the shunt (BFS) were measured or calculated before TIPS, after 15 minutes and, finally, after 90 days. Twenty-five liver cirrhosis patients without diabetes and without TIPS were included as the control group (CG). Oral glucose tolerance tests (OGTTs) were carried out at 0, 1, 7, 30 and 90 days after TIPS or after inclusion in the study. Indices related to glycometabolism and liver function, which included biochemical values, were also investigated. PVP changed immediately from 39.43 ± 1.29 cmH(2)O to 21.43 ± 1.42 cmH(2)O and remained stable thereafter. A pronounced increase in CO was observed after TIPS, while BFS did not change significantly. Also, glycosylated hemoglobin A(1c) (HbA(1c)), fasting plasma glucose (FPG), fasting plasma C-peptide (FPC), glucagon-like peptide-1 (GLP-1) and 2-h post-challenge plasma glucose (2 hPG) were non significantly increased after the shunt. Statistically significant hyperinsulinemia and hyperglucagonemia persisted for 90 days after TIPS. In addition, TIPS was followed by an increase in insulin resistance (IR) and β-cell function. Thirty-four patients in the EG and 15 in the CG were diagnosed with diabetes or prediabetes after 90 days. No significant differences in biochemical values were observed 90 days after the shunt. In addition to causing hemodynamic changes, TIPS augments hyperglucagonemia because of increased secretion and decreased clearance of glucagon in the liver, whereas IR deteriorates after the procedure. However, glycemic control does not worsen after TIPS, and the procedure is not associated with a higher risk of diabetes largely because of the simultaneous increase in insulin.

Dynamic contrast-enhanced magnetic resonance imaging with Gd-EOB-DTPA for the evaluation of liver fibrosis in chronic hepatitis patients

To develop a non-invasive MRI method for evaluation of liver fibrosis, with histological analysis as the reference standard. The study protocol was approved by the Institutional Review Board for Human Studies of our hospital, and written informed consent was obtained from all subjects. Seventy-nine subjects who received dynamic contrast-enhanced MRI (DCE-MRI) with Gd-EOB-DTPA were divided into three subgroups according to Metavir score: no fibrosis (n = 30), mild fibrosis (n = 34), and advanced fibrosis (n = 15). The DCE-MRI parameters were measured using two models: (1) dual-input single-compartment model for arterial blood flow (F (a)), portal venous blood flow, total liver blood flow, arterial fraction (ART), distribution volume, and mean transit time; and (2) curve analysis model for Peak, Slope, and AUC. Statistical analysis was performed with Student's t-test and the nonparametric Kruskal-Wallis test. Slope and AUC were two best perfusion parameters to predict the severity of liver fibrosis (>F2 vs. ≦F2). Four significantly different variables were found between non-fibrotic versus mild-fibrotic subgroups: F (a), ART, Slope, and AUC; the best predictor for mild fibrosis was F (a) (AUROC:0.701). DCE-MRI with Gd-EOB-DTPA is a noninvasive imaging, by which multiple perfusion parameters can be measured to evaluate the severity of liver fibrosis.

Terlipressin: An Asset for Hepatologists!

Terlipressin: An Asset for Hepatologists!

Chronic Liver Disease: Systemic and Splanchnic Venous Flow Mapping with Optimized Cine Phase-Contrast MR Imaging Validated in a Phantom Model and Prospectively Evaluated in Patients1

To validate magnetic resonance (MR) imaging cine phase-contrast blood flow mapping in vitro and in patients with chronic liver disease, with or without portal hypertension, and to assess the accuracy of azygos, splanchnic, and systemic blood flow measured with MR imaging in the detection of high-risk esophageal varices and compare these measurements with endoscopic evaluation, the reference standard. The local ethics committee approved this study. Patients gave written informed consent. Two phantoms were used to validate the MR imaging phase-contrast flow sequence. Patients with liver cirrhosis (n = 59), chronic liver disease without cirrhosis (n = 12), and nodular regenerative hyperplasia (NRH) (n = 11), and healthy control subjects with no liver disease (n = 25) were included. The patients underwent upper digestive system endoscopy. Mean abdominal aorta, portal venous, and azygos blood flow was measured on MR images, which were reviewed by two blinded observers to determine the presence and grade of esophageal varices. The reproducibility and intra- and interobserver variability of the blood flow measurements were assessed with intraclass correlation coefficients (ICCs). The performance of the MR blood flow measurements in staging high-risk varices was determined with receiver operating characteristic curve analysis. The correlation between MR visual analysis and endoscopic grading was assessed by using κ statistics. MR flow rate measurements had excellent correlations with actual flow values in vitro (ICC > 0.990 for phantoms 1 and 2). Mean aortic flow was significantly higher in patients with cirrhosis than in control subjects (P < .001). Mean azygos flow was significantly higher in patients with cirrhosis than in patients with chronic liver disease without cirrhosis (P = .005) and control subjects (P < .001). Low intra- and interobserver variability (ICC > 0.990 for each blood flow type) and high reproducibility (ICC > 0.850 for each blood flow type) were demonstrated. The optimal cutoff mean azygos flow value was 2.3 mL/sec for varices with grades of 2 or higher. MR imaging azygos flow measurement appears to be a promising technique for detecting high-risk esophageal varices in patients with portal hypertension.

Four‐dimensional velocity mapping of the hepatic and splanchnic vasculature with radial sampling at 3 tesla: A feasibility study in portal hypertension

To demonstrate the feasibility of PC-VIPR (Phase Contrast Vastly undersampled Imaging with Projection Reconstruction) for the depiction and hemodynamic analysis of hepatic and splanchnic vessels in patients with portal hypertension. Twenty-four cirrhotic patients (55.9 ± 10.4 years) were scanned using 5-point PC-VIPR for high spatial resolution imaging with large volume coverage at 3 Tesla (T) using a 32-channel body coil. Vessel segmentation and hemodynamic visualization included color-coded three-dimensional (3D) streamlines and particle traces. Segmentation quality was compared with contrast-enhanced multi-phase liver imaging. Flow pattern analysis was performed in consensus of three readers. The MELD score was calculated to estimate disease severity and was correlated to image quality. Good to excellent visualization quality was achieved in 23/24 cases. All arterial vessels and 144/168 vessels of the portal venous (PV) circulation were unambiguously identified. No correlation with the MELD score was found. Eight of 148 vessels of the PV circulation demonstrated reverse (hepatofugal) flow. Hepatofugal flow in small tributaries to PV flow were present in three cases despite hepatopetal flow in the PV. This feasibility study demonstrates the feasibility of PC-VIPR for simultaneous morphological and hemodynamic assessment of the hepatic and splanchnic vasculature in cirrhosis and portal hypertension. Future studies with quantitative analyses are warranted.

Congenital extrahepatic portosystemic shunt (Abernethy malformation) treated endovascularly with vascular plug shunt closure

A 3-year-old boy, who presented with progressive cyanosis and hypoxia, was diagnosed with a large congenital extrahepatic portosystemic shunt, interrupted IVC with azygos continuation, and multiple congenital anomalies. Traditionally open and laparoscopic surgical techniques have been used to treat this malformation. Endovascular repair using a 16-mm Amplatzer vascular plug (AGA Medical Corporation, Golden Valley, Minnesota, USA) was used to occlude the shunt. Immediate post-placement venography demonstrated cessation of flow within the shunt and increased portal venous flow. The patient's hypoxia and cyanosis decreased significantly, and he was discharged on the 5th post-procedure day in stable clinical condition. Three months follow-up evaluation demonstrated the vascular plug in place, unchanged in position.

Accurate perioperative flow measurement of the portal vein and hepatic and renal artery: A role for preoperative MRI?

BackgroundQuantification of abdominal blood flow is essential for a variety of gastrointestinal and hepatic topics such as liver transplantation or metabolic flux measurement, but those need to be performed during surgery. It is not clear whether Duplex Doppler Ultrasound during surgery or MRI before surgery is the tool to choose. ObjectiveTo examine whether preoperative evaluation of abdominal blood flow using MRI could prove to be a useful and reliable alternative for the perioperative sonographic approach. MethodsIn this study portal and renal venous flow and hepatic arterial flow were sequentially quantified by preoperative MRI, preoperative and perioperative Duplex Doppler Ultrasound (DDUS). 55 Patients scheduled for major abdominal surgery were studied and methods and settings were compared. Additionally, average patient population values were compared. ResultsMean (±SD) plasmaflow measured by perioperative DDUS, preoperative DDUS and MRI, respectively was 433±200/423±162/507±96ml/min (portal vein); 96±70/74±41/108±91ml/min (hepatic artery); 248±139/201±118/219±69ml/min (renal vein). No differences between the different settings of DDUS measurement were detected. Equality of mean was observed for all measurements. Bland Altman Plots showed widespread margins. Hepatic arterial flow measurements correlated with each other, but portal and renal venous flow correlations were absent. ConclusionsSurgery and method (DDUS vs. MRI) do not affect mean flow values. Individual comparison is restricted due to wide range in measurements.Since MRI proves to be more reliable with respect to inter-observer variability, we recommend using mean MRI results in experimental setups.

Deconvolution assessment of splenic and splanchnic contributions to portal venous blood flow in liver cirrhosis

To devise a noninvasive imaging method for resolving the relative contribution of splenic and splanchnic blood flow to portal venous flow and derive quantitative estimates for parameters pertaining to splenic and portal hemodynamics. Tracer concentration-time curves of the aorta, portal vein, and spleen can be extracted from dynamic contrast-enhanced (DCE) CT or MR images. A combination of two tracer analysis approaches, namely arterial-venous sampling and residual tracer deconvolution, is proposed to model these concentration-time curves and derive hemodynamic parameters pertaining to splenic and portal circulation. Clinical feasibility of the proposed method was explored using DCE CT datasets of eight cirrhotic patients. Monte Carlo simulations were performed to evaluate the confidence of the parameter estimates. Portal blood flow was estimated to be 763.8 +/- 438.1 ml/min in cirrhotic patients and the splenic contribution was found to be elevated (0.75 +/- 0.22). Estimates of splenic blood flow (582 +/- 420 ml/min) and transit time (15.3 +/- 10.1 s) in cirrhotic patients were consistent with reported values obtained using duplex Doppler ultrasound and dynamic scintigraphy, respectively. This study shows the feasibility of noninvasive assessment of splenic and portal hemodynamic parameters by DCE imaging using a combination of tracer kinetics modeling techniques.

Ischemic liver injuries after hepatic artery embolization in patients with delayed postoperative hemorrhage following hepatobiliary pancreatic surgery

Many collateral pathways to the liver are dissected during hepatobiliary pancreatic surgery and, if the arterial bleeding is massive and a hematoma becomes larger, the adjacent portal vein can be compressed with impairment of the portal venous flow. To evaluate the frequency and severity of ischemic liver injuries after hepatic artery embolization in patients with delayed postoperative arterial hemorrhage after hepatobiliary pancreatic surgery. Eighteen patients undergoing proper or common hepatic artery embolization for delayed postoperative arterial hemorrhage after hepatobiliary pancreatic surgery achieved hemostasis. To evaluate the frequency and severity of ischemic liver injuries, the liver enzyme levels and CT findings before and after hepatic artery embolization were retrospectively compared and the clinical outcomes after hepatic artery embolization were analyzed. Angiographic findings were also analyzed to reveal any association with development of ischemic liver injuries after hepatic artery embolization. Ischemic liver injuries were observed in 15 (83%) of 18 patients undergoing hepatic artery embolization for postoperative hemorrhage. Injuries included hepatic infarction combined with abscess in one (5%) patient, hepatic infarction in 12 (67%) patients, and transient hepatic ischemia/dysfunction in two (11%). As for the extent of hepatic infarction, lobar infarction developed in two patients and subsegmental infarction in 11. One patient with right hepatic lobar infarction died of hepatic failure 11 days after hepatic artery embolization. In the other 14 patients with ischemic liver injuries, the elevated liver enzymes returned to baseline levels within two weeks. All of the four patients with portal vein stenosis, four patients with no hepatic arterial flow on post-embolization angiogram, and one patient with both had hepatic infarction after hepatic artery embolization. No ischemic liver injuries developed after hepatic artery embolization in three patients with no portal vein stenosis and bilobar hepatic arterial flow via the left hepatic artery aberrantly arising from the left gastric artery or from the common hepatic artery. Ischemic liver injuries can develop in most patients undergoing hepatic artery embolization for postoperative arterial hemorrhage after hepatobiliary pancreatic surgery; hepatic infarction appears to be the most frequent type of ischemic liver injury. Hepatic artery embolization for postoperative arterial hemorrhage after hepatobiliary pancreatic surgery may carry a great risk of ischemic liver injury if a patient has portal vein stenosis or no aberrant hepatic artery.

Arterial blood flow predicts graft survival in liver transplant patients

Proper liver perfusion is essential for sufficient organ function after liver transplantation. The aim of this study was to determine the effects of portal and arterial blood flow on liver function and organ survival after liver transplantation. The arterial and portal venous blood flow was measured intraoperatively by transit time flow measurement after reperfusion for 290 consecutive liver transplants. The graft survival, hepatic cell damage (alanine aminotransferase and aspartate aminotransferase), and liver function (prothrombin ratio and bilirubin) were determined. Grafts were stratified into groups according to arterial blood flow measurements [<100 mL/minute for arterial blood flow group I (ART I), 100-240 mL/minute for ART II, and ≥ 240 mL/minute for ART III] and portal venous blood flow measurements (<1300 mL/minute for portal venous blood flow group I and ≥ 1300 mL/minute for portal venous blood flow group II). With multivariate analysis, the impact of blood flow on graft survival was determined, and potential confounders were considered. Decreased portal venous blood flow was associated with significantly less organ survival in univariate analysis but not in multivariate analysis. In contrast, the arterial blood flow was significantly correlated with organ survival after liver transplantation in univariate and multivariate analyses [hazard rate ratio = 2.5, confidence interval = 1.6-4.1, P < 0.001, median survival = 56.6 (ART I), 82.7 (ART II), or 100.7 months (ART III)]. Moreover, low arterial blood flow resulted in impaired postoperative organ function and higher rates of primary nonfunction. Biliary complications were not affected by blood flow. Other risk factors for graft failure that were identified by multivariate analysis included retransplantation, histidine tryptophan ketoglutarate solution versus University of Wisconsin solution, and donor treatment with epinephrine. Impaired arterial blood flow after reperfusion represents a significant predictor of primary graft nonfunction and is associated with impaired graft survival. Whether the intraoperative measurement of hepatic arterial flow is predictive of graft survival should be evaluated in a prospective trial.

Critical Physiological and Surgical Considerations for Hydrodynamic Pressurization of Individual Segments of the Pig Liver

Hydrodynamic gene delivery to the liver is a promising approach for liver gene therapy in the clinic, but levels of gene expression in larger species have been much less than in rodents. The development of surgical techniques for pressurizing individual liver segments and the establishment of whether hepatic vascular anatomy in fact permits pressurization of individual segments are critical issues that need to be addressed. We have evaluated these issues using hydrodynamic delivery to individual segments of the pig liver, via branches of both portal and hepatic veins. Our objective was to develop surgical techniques that achieve elevated vascular pressures within individual liver segments with small volumes, but without interruption of portal blood flow or reduction in venous return to the heart. We report that, without specific surgical interventions to obstruct outflow of DNA solution from the targeted liver segment, little or no increase in intrahepatic vascular pressure occurs. We demonstrate, for the first time, that selective pressurization of individual liver segments is possible without compromising portal venous flow or venous return to the heart. Thus, hydrodynamic gene delivery to individual liver segments is technically achievable in a clinical setting, but will require open abdominal surgery rather than minimally invasive techniques.

Portal blood flow via the peribiliary vascular plexus demonstrated by contrast‐enhanced ultrasonography with Sonazoid

We report two cases in which portal blood flow via the peribiliary vascular plexus (PBP) was clearly demonstrated using contrast-enhanced intra-operative ultrasonography (CE-IOUS). Two patients who underwent hemihepatectomies were investigated using CE-IOUS. Before injection of the contrast medium, both the hepatic arterial and portal venous flows of the hemiliver to be resected were interrupted by ligating those corresponding vessels at the hepatic hilum. Subsequently, the perfluorobutane microbubbles were injected intravenously. In the early vascular phase, a remarkable intermittent flow was visualized in the lumen of the portal branches whose inflows were interrupted. The flow of the portal vein then disappeared as a result of ligating the hepatic duct concomitantly with the surrounding connective tissue. We considered that the portal venous flow appearing under the condition of total disruption of original inflow was supplied from the hepatic artery through the PBP. This is the first report of blood flow via the PBP in human liver visualized by dynamic image study.

Portal Hypertension: Pathophysiology, Diagnosis, and Treatment

Portal hypertension (PH) is the result of increased vascular resistance in the portal circulation, increased portal venous blood flow, or both. In veterinary medicine, where portal pressure is seldom measured directly, the diagnosis of PH often is inferred from identification of associated complications including multiple acquired portosystemic shunts, ascites, and hepatic encephalopathy. Likewise, treatment of PH primarily is aimed at controlling these complications. The goal of this review is to provide an update on the pathophysiology, diagnosis, and treatment of PH. The review draws from information in the veterinary hepatology literature, reviews, and consensus statements in human hepatology and the literature on experimental models of PH.

Experience With Duplex Sonographic Evaluation of Meso-Rex Bypass in Extrahepatic Portal Vein Obstruction

Meso-Rex bypass is a surgical procedure for managing extrahepatic portal vein obstruction in children. Although duplex sonography has been used for assessing the patency of the bypass graft and the changes in the intrahepatic portal venous system after the surgery, there was little sonographic description of functioning and dysfunctioning bypass grafts found in the literature. In this case series, we retrospectively evaluated duplex sonography of functioning and dysfunctioning bypass grafts in 5 pediatric patients who received meso-Rex bypass grafts. Sonography was performed preoperatively and postoperatively within 48 hours, 1 to 2 weeks later, and at follow-up 1 month and up to 3 years later. Changes in the direction and velocity of the flow in the intrahepatic portal veins and bypass grafts and diameters of the grafts and the left portal veins were analyzed. Preoperative sonography revealed varied extension of extrahepatic portal vein occlusion with cavernous transformation and diminished intrahepatic portal venous flow, whereas postoperative studies showed a rapid increase of the intrahepatic portal flow via the meso-Rex bypass graft in all cases. A patent graft with reversed flow in the left portal vein was a predominant feature of a functioning graft. In contrast, absent flow in the graft with diminished flow or an altered flow direction in the left portal vein indicated graft failure. It is believed that duplex sonography provides a valuable tool for monitoring the hemodynamic changes in the portal venous system and detecting graft malfunction.

Reversible Decrease of Portal Venous Flow in Cirrhotic Patients: A Positive Side Effect of Sorafenib

Portal hypertension, the most important complication with cirrhosis of the liver, is a serious disease. Sorafenib, a tyrosine kinase inhibitor is validated in advanced hepatocellular carcinoma. Because angiogenesis is a pathological hallmark of portal hypertension, the goal of our study was to determine the effect of sorafenib on portal venous flow and portosystemic collateral circulation in patients receiving sorafenib therapy for advanced hepatocellular carcinoma. Porto-collateral circulations were evaluated using a magnetic resonance technique prior sorafenib therapy, and at day 30. All patients under sorafenib therapy had a decrease in portal venous flow of at least 36%. In contrast, no specific change was observed in the azygos vein or the abdominal aorta. No portal venous flow modification was observed in the control group. Sorafenib is the first anti-angiogenic therapy to demonstrate a beneficial and reversible decrease of portal venous flow among cirrhotic patients.