Primary Budd-Chiari syndrome: ultrasonic demonstration

Stenting of Inferior Right Hepatic Vein in a Patient with Budd-Chiari Syndrome: A Case Report

A Japanese man in his 20s was referred to our hospital with a two-month history of abdominal fullness and leg edema. Abdominal computed tomography revealing massive ascites and ostial blockage of the main hepatic veins, and angiographic evaluation demonstrating obstruction of the main hepatic veins yielded a diagnosis of Budd-Chiari syndrome (BCS). Diuretic agents were prescribed for the ascites but failed to provide relief. The patient was referred to our department for further evaluation and treatment. Angiography showed ostial obstruction of the main hepatic veins, with most of the portal hepatic flow draining from an inferior right hepatic vein (IRHV) into the inferior vena cava (IVC) thorough an intrahepatic portal venous and venovenous shunt. Access between the main hepatic veins and IVC was impossible, but cannulation between the IRHV and IVC was achieved. Because of the venovenous connection between the main hepatic vein and the IRHV, metallic stents were placed into two IRHVs to decrease congestion in the hepatic venous outflow. After stent placement followed by balloon expansion, the gradient pressure between the hepatic vein and IVC improved remarkably. The ascites and lower leg edema improved postoperatively, and long-term stent patency (6 years) was achieved.

Quantitative anatomy of the large variant right hepatic vein: A systematic three-dimensional analysis

Anatomical variations of the right hepatic vein, especially large variant right hepatic veins (≥5 mm), have important clinical implications in liver transplantation and resection. This study aimed to evaluate anatomical variations of the right hepatic vein using quantitative three-dimensional visualization analysis. Computed tomography images of 650 patients were retrospectively analyzed, and three-dimensional visualization was applied using the derived data to analyze large variant right hepatic veins. The proportion of the large variant right hepatic vein was 16.92% (110/650). According to the location and number of the variant right hepatic veins, the configuration of the right hepatic venous system was divided into seven subtypes. The length of the retrohepatic inferior vena cava had a positive correlation with the diameter of the right hepatic vein (rs = 0.266, p = 0.001) and the variant right hepatic veins (rs = 0.211, p = 0.027). The diameter of the right hepatic vein was positively correlated with that of the middle hepatic vein (rs = 0.361, p < 0.001), while it was inversely correlated with that of the variant right hepatic veins (rs = -0.267, p = 0.005). The right hepatic vein diameter was positively correlated with the drainage volume (rs = 0.489, p < 0.001), while the correlation with the variant right hepatic veins drainage volume was negative (rs = -0.460, p < 0.001). The number of the variant right hepatic veins and their relative diameters were positively correlated (p < 0.001). The volume and percentage of the drainage area of the right hepatic vein decreased significantly as the number of the variant right hepatic vein increased (p < 0.001). The findings of this study concerning the variations of the hepatic venous system may be useful for the surgical planning of liver resection or transplantation.

Comparison of Balloon-Occluded Thrombolysis with Catheter-Directed Thrombolysis in Patients of Budd-Chiari Syndrome with Occluded Direct Intrahepatic Portosystemic Shunt

Objectives  Direct intrahepatic portosystemic shunt (DIPS) stent placement is an effective treatment for patients with Budd-Chiari syndrome (BCS); however, thrombotic occlusion of DIPS stent remains a cause of concern. The purpose of this study is to describe a novel technique of balloon-occluded-thrombolysis (BOT) for occluded DIPS stent, and compare it with the conventional catheter-directed-thrombolysis (CDT). Methods  In this retrospective study, the hospital database was searched for BCS patients who underwent DIPS revision for thrombotic stent occlusion between January 2015 and February 2021. Patients were divided into CDT group and BOT group. The groups were compared for technical success, total dose of thrombolytic agent administered, duration of hospital stay, and primary assisted stent patency rates at 1- and 6-month follow-up. Results  CDT was performed in 12 patients, whereas 21 patients underwent BOT. Complete recanalization was achieved in 66.7% (8 of 12) patients of CDT group as compared to 81% (17 of 21) patients of BOT group (nonsignificant difference, p  = 0.420). BOT group had a short hospital stay (1.8 ± 0.7 vs. 3.5 ± 1.0 days) and required less dose of thrombolytic agent ([2.2 ± 0.4]x10 5 IU versus [8.3 ± 2.9]x10 5 IU of urokinase) as compared to the CDT group and both differences were statistically significant ( p  < 0.001). Further, 6-month patency rate was higher in BOT group as compared to CDT group ( p  = 0.024). Conclusion  The novel BOT technique of DIPS revision allows longer contact time of thrombolytic agent with the thrombi within the occluded stent. This helps in achieving fast recanalization of thrombosed DIPS stent with a significantly less dose of thrombolytic agent required, thus reducing the risk of systemic complications associated with thrombolytic administration.

Accuracy of computed tomographic angiography in the diagnosis of patients with inferior vena cava partial obstruction in Budd-Chiari syndrome

BACKGROUND AND AIM

The diagnosis of the partially obstructed inferior vena cava (IVC) in Budd-Chiari syndrome (BCS) patients has received little attention. We aimed to evaluate the diagnostic accuracy of computed tomographic angiography (CTA) for patients with BCS and a partially obstructed IVC.

METHODS

A total of 329 patients with BCS and an obstructed IVC were endovascularly treated with balloon dilation and/or stent placement. All patients underwent a CTA examination prior to endovascular treatment, and the data were retrospectively reviewed. The presence of a round, oval, irregular shape or jet sign low-density area without enhancement within the enhanced proximal IVC was considered a sign of a partially obstructed IVC. Digital subtraction angiography was used as the gold standard.

RESULTS

The results from the digital subtraction angiography revealed a partially obstructed IVC in 108 BCS patients and a complete obstruction in 221 patients. The CTA discovered a partially obstructed IVC in 99 patients and a completely obstructed IVC in 230 patients. From the CTA results, 15 were false negatives, and six were false positives. The patient-based evaluation yielded an accuracy of 93.6%, a sensitivity of 86.1%, specificity of 97.3%, positive predictive value of 93.9%, and negative predictive value of 93.5% for the detection of BCS patients with a partial IVC obstruction.

CONCLUSIONS

Computed tomographic angiography offered a high diagnostic accuracy and sensitivity in BCS patients with a partially obstructed IVC. The low-density area within the enhanced proximal IVC above the membrane in artery phase can be considered a reliable indicator of a stenotic IVC in BCS patients.

Intraoperative ultrasonographic detection of communicating veins between adjacent hepatic veins during hepatectomy for tumours at the hepatocaval confluence

BACKGROUND

The presence of communicating veins between adjacent hepatic veins may allow parenchyma-sparing hepatectomy. Taking advantage of improvements in ultrasound technology, such as e-flow modality, a study of the presence of communicating veins was conducted in patients with hepatic tumours at the caval confluence.

METHODS

Consecutive patients undergoing surgery between October 2007 and December 2009 for hepatic tumours in contact with or invading a hepatic vein at its caval confluence were included. Communicating vein mapping by means of e-flow intraoperative ultrasonography (EF-IOUS) was carried out.

RESULTS

A total of 20 patients were enrolled. Communicating veins between adjacent hepatic veins or with the inferior vena cava were detected in 16 patients. The median number of communicating veins was 1 (range 0-5). The total number of lesions removed was 126 (range 1-46). In 11 of 12 patients requiring resection of a hepatic vein, communicating veins enabled a parenchyma-sparing procedure to be performed. No patient had a formal major hepatectomy. There was no postoperative mortality or major morbidity.

CONCLUSION

EF-IOUS estimation of the frequency of communicating veins between adjacent hepatic veins suggests that such veins are common. This may facilitate parenchyma-sparing procedures in patients with hepatic tumours encroaching on major hepatic veins.

Liver cirrhosis and hepatocellular carcinoma in hepatic vena cava disease, a liver disease caused by obstruction of inferior vena cava

PURPOSE

Hepatic vena cava disease (HVD), a form of Budd-Chiari syndrome, is caused by the obstruction of hepatic portion of the inferior vena cava. It is a chronic disease characterized by the development of liver cirrhosis (LC) and hepatocellular carcinoma (HCC). As HVD occurred in areas with high incidence of hepatitis B virus (HBV) infection and some patients tested HBsAg positive, it was thought to be the cause of LC and HCC. To assess the pathogenesis of LC or HCC in HVD, a long-term follow-up study was done.

METHOD

Fifty-six patients with HVD diagnosed by ultrasound (US) and confirmed by cavography in 31 and liver biopsy in 34 were followed up for an average of 14.8 +/- 9 years. The occurrence of LC was diagnosed by US and/or liver biopsy and that of HCC by US, elevated level of alpha-fetoprotein, and liver biopsy or fine-needle aspiration cytology, or computed tomographic scan. Other risk factors for LC/HCC such as alcohol use and HBV and hepatitis C virus (HCV) infections were assayed.

RESULTS

Forty-four (78.5%) and 6 (10.7%) patients developed cirrhosis and HCC, respectively. LC/HCC occurred more frequently among those who had severe or frequent acute exacerbations (P = 0.017), but it was not related to alcohol use or HBV and HCV infections.

CONCLUSION

HVD is independent risk factors for LC and HCC. Severe and/or recurrent loss of hepatocytes caused by hepatic venous outflow obstruction and/or thrombotic obstruction of small radicals of hepatic and portal veins that occurred during acute exacerbations was considered important in the pathogenesis of LC and HCC in HVD.

Unusual hepatic-portal-systemic shunting demonstrated by Doppler sonography in children with congenital hepatic vein ostial occlusion

PURPOSE

This report describes unusual changes in the hepatic vasculature in 3 children presenting with upper gastrointestinal hemorrhage.

METHODS

The study included 3 children (ages 5-8 years) who presented with hematemesis. All had mild hepatosplenomegaly and normal liver function. Esophageal varices were demonstrated in all on upper endoscopy. Color and spectral Doppler sonography was performed to assess the hepatic vasculature, including the hepatic veins (HVs), portal vein (PV), hepatic artery (HA), and inferior vena cava (IVC).

RESULTS

The HVs were all patent but with ostial occlusion at the point of their communication with the IVC. Complete flow reversal was shown inside the HVs, with blood draining into collateral vessels at the liver surface and paraumbilical vein. In one patient, the paraumbilical vein could be traced to its communication with the right external iliac vein. In all children, the direction of flow in the PV, HA, and IVC was normal. After endoscopic sclerotherapy, all children were shown to be in good general condition and to have normal liver function for a follow-up period of 15-36 months.

CONCLUSIONS

Ostial occlusion of the HV is a rare cause of hepatic outflow obstruction in children. Doppler sonography is a valuable, noninvasive imaging technique for evaluation of the hepatic vasculature and the accompanying shunting pathways in such cases.

Doppler sonography of the native liver

Doppler sonography is being used routinely in evaluating the vascular structures of the native liver because of its ease of use, lower cost, easier availability, lack of need for X-ray and accuracy. Doppler sonography can well demonstrate the vascularization of liver tumors, portal vein thrombosis, portal vein abnormalities in patients with portal hypertension and hepatic venous findings in patients with Budd Chiari syndrome. The purpose of this article is to present information about Doppler sonography of the native liver and to show its usefulness in the evaluation of hepatic vascular diseases.

Duplex Doppler sonography in patients with Budd-Chiari syndrome

BACKGROUND

Angiography has been the mainstay for diagnosis of Budd-Chiari syndrome even though other modalities are increasingly being used. We have evaluated our findings of duplex Doppler sonography (DDS) in patients with Budd-Chiari syndrome.

METHODS

Duplex Doppler sonography was performed in 37 consecutive angiographically proven patients with Budd-Chiari syndrome.

RESULTS

Real time ultrasonography showed abnormalities of right, middle and left hepatic veins (HV) in 21, 15 and 18 patients, respectively. Duplex Doppler sonography showed abnormal flow patterns in 37, 22 and 31 patients in the right, middle and left HV, respectively, thereby increasing the diagnostic yield by 40%. An abnormal waveform in one or more HV was present in all 37 patients. Uniphasic flow was the commonest abnormality and was seen in 22, nine and 14 patients, respectively, in the right, middle and left HV, while there was no flow in five, four and seven patients in the right, middle and left HV, respectively. Intrahepatic collaterals were seen in 35 of 37 patients (94.6%). Hepatopetal flow was found in the portal vein of 21 of 23 patients (91.3%), while flow was hepatofugal in one and portal vein thrombosis was found in another.

CONCLUSION

Duplex Doppler sonography is a useful procedure which helps in the diagnosis of patients with Budd-Chiari syndrome.

Ultrasonically guided inferior vena cava stent placement: experience in 83 cases

PURPOSE

Traditionally, inferior vena cava (IVC) stent placement is performed with fluoroscopic guidance. The object of this study was to evaluate use of ultrasound (US) as guidance for IVC stent placement for the management of Budd-Chiari syndrome.

MATERIALS AND METHODS

Eighty-three patients with IVC membranous stenosis (n = 30), membranous occlusion (n = 19), segmental stenosis (n = 21), or segmental occlusion (n = 13) underwent IVC recanalization, balloon dilation, and stent placement under US guidance. Among the 83 patients, 67 had at least one patent hepatic vein, while 16 patients had three occluded hepatic veins.

RESULTS

IVC stents were successfully placed in 79 of 83 patients, with a success rate of 95%. After the procedure, the symptoms and signs of IVC obstruction disappeared or markedly improved in all patients, and the blockage of hepatic outflow was alleviated in 67 patients. Pericardial effusion, complete atrial ventricular block, and stent migration into the right atrium occurred, respectively, in one patient. During 1-46-month follow-up, stent restenosis occurred in one patient; the other stents remained open and functioned effectively.

CONCLUSION

Because of the absence of nonionizing radiation and iodinated contrast material, and its low cost, US is well suited and often preferred for guidance of IVC stent placement.

Proposal of a new nomenclature for Budd-Chiari syndrome: hepatic vein thrombosis versus thrombosis of the inferior vena cava at its hepatic portion

Budd-Chiari syndrome (BCS) was initially defined as a symptomatic occlusion of the hepatic veins, but subsequent reports on various obliterative changes that occur in the hepatic portion of the inferior vena cava (IVC) and hepatic vein orifices have resulted in a broadened and ambiguous definition. Membranous obstruction of the inferior vena cava has been regarded by many as a congenital vascular malformation, but its relation to the classical BCS has remained obscure. With modern imaging and recent histological study of new cases, membranous obstruction of the IVC is now considered to be a sequela to thrombosis. How to classify various forms of occlusion and stenosis of the IVC and hepatic vein ostia is a major challenge. In this review, we emphasize that primary hepatic vein thrombosis (classical Budd-Chiari) and an obliterative disease predominantly affecting the hepatic portion of the IVC, both of which account for most patients with venous outflow block, are clinically quite different. In the West, the former is more common than the latter, which constitutes the vast majority of cases of outflow block in developing countries such as Nepal, South Africa, China, and India. The latter is frequently complicated by hepatocellular carcinoma (HCC), and primary hepatic vein thrombosis is not. The major cause of thrombosis is a hypercoagulable state in hepatic vein thrombosis, but more of the latter cases are idiopathic. The clinical presentation of the latter is milder, and onset is frequently inapparent, whereas the former is more severe, sometimes causing acute hepatic failure. Markedly enlarged subcutaneous veins over the body trunk characterize the latter. We propose that these two disorders be clinically distinguished with a suggested term "obliterative hepato-cavopathy" for the latter against classical BCS.

Which is the best surgery for Budd-Chiari syndrome: venous decompression or liver transplantation? A single-center experience with 50 patients

The optimal treatment of Budd-Chiari syndrome (BCS) remains an open question. It is still a matter of controversial discussion whether venous decompression or liver transplantation is superior. To elucidate the role and prognosis of both surgical options in our own experience, a consecutive series of 50 patients treated between 1981 and 1993 was retrospectively analyzed. Twelve patients had different types of portosystemic shunts or local decompressive procedures, and transplantation was performed in 43 cases, including five with previous conventional surgery. The overall mortality of 18 of 50 was conventional surgery. The overall mortality of 18 of 50 was concentrated within the early postoperative period, with no patient lost after 1 year. In the venous decompression group, the success rate was only 29%, and treatment failure was closely related to the finding of cirrhosis or technical problems like vascular thrombosis. After transplantation, early complications were rejection, primary nonfunction, or graft necrosis, and contributed significantly to the risk of sepsis. Thirty of 43 liver recipients are currently alive, including four rescued after failed decompressive surgery, with 1- and 10-year survival of 69%, and excellent recurrence-free rehabilitation. These results clearly indicate that patient selection plays a dominant prognostic role in the treatment of BCS. Venous decompression and liver transplantation should both be integrated in a common therapeutic concept, and the individual decision for the preferred approach must be based on the leading clinical symptom: portal hypertension or liver failure, together with the assessment of reversibility of hepatic damage, and the potential of cure of the underlying disease.

Sonographic diagnosis of hepatic vascular disorders

Perhaps the most valuable application of duplex sonography in the abdomen is in the diagnosis of vascular disorders of the liver. Duplex sonography provides an accurate assessment of the portal and hepatic venous systems that is both noninvasive and convenient, because the examination can be conducted at the bedside. In this article, the normal features of portal and hepatic venous flow are considered as well as the sonographic manifestations of pathological conditions, including: (1) portal hypertension; (2) portosystemic collaterals; (3) portal vein thrombosis; and (4) hepatic vein thrombosis (Budd-Chiari syndrome).

Budd-Chiari syndrome: imaging with pathologic correlation

We retrospectively evaluated 21 patients with Budd-Chiari syndrome who underwent liver transplant. The pathological findings were correlated with imaging studies that included computed tomography (CT) in all cases, sonography in 20, and magnetic resonance (MR) in 15. Pathological features of Budd-Chiari syndrome in subacute or chronic form, such as parenchymal fibrosis, hemorrhage, and congestion, were found in all resected livers. These occurred usually in conjunction with restricted hepatic veins due to thrombosis or fibrosis with partially recanalized lumen. The status of hepatic veins was correctly assessed and correlated with pathology in 13 of 20 patients who had sonograms, in 12 of 15 patients who had MR, and in nine of 18 patients with contrast-enhanced CT scans. Patency of the inferior vena cava was well seen by all three modalities; parenchymal abnormalities were best visible on CT (19 of 21), while ascites, caudate lobe enlargement and collateral vessels were best detected with MR or CT. We conclude that each imaging modality offers certain values and limitations in the assessment of vascular or parenchymal findings in Budd-Chiari syndrome.

Budd-Chiari syndrome: analysis of 30 cases

The authors report their experience with 30 adult patients with Budd-Chiari syndrome (BCS), which is a rare and serious disorder, characterized by hepatic outflow obstruction caused by many different conditions. The diagnosis was based on the clinical data, ultrasonography (US), vena cavography and hepatic venography, computed tomography (CT), and liver biopsy. Behçet's disease (BD) was found in 10 patients with BCS as an underlying disease. Two patients used oral contraceptive drugs, 2 had liver tumor hepatocellular carcinoma and liver lymphoma, and 1 patient had chronic lymphocytic leukemia. Despite full investigation, the authors could not find any obvious underlying cause in the other 15 patients. The results suggest that (1) BCS must be considered as a possible complication in patients with Behçet's disease when they have hepatomegaly even if there were no cardinal manifestations of the disease at the time of admission, and BD is the most common etiologic factor in BCS (33%) in Turkey, where the incidence of Behçet's disease is relatively high. (2) Anti-aggregant treatment seems to be effective in many instances. (3) There were space-occupying lesion-like appearances in the liver of 7 cases by CT and US examination in the acute stage, and these disappeared on the follow-up CT and US in 5 patients but continued in 2. BCS should thus be differentiated from other liver lesions. (4) There were other great-vessel involvements in 43% of the cases, mostly venous, but only 1 pulmonary arterial occlusion.

Ultrasound study in the diagnosis of primary Budd-Chiari syndrome (obstruction of the inferior vena cava)

Primary Budd-Chiari syndrome, obstruction of the hepatic portion of the inferior vena cava (IVC), is a rare disorder, but relatively prevalent in the Far East, northern India and Africa. Ultrasound examination was carried out on 9 patients with primary Budd-Chiari syndrome. There were 5 men and 4 women aged 27-60 years. In all the 9 cases, the diagnosis was confirmed by cavography and liver histology. Moreover, 7 of the 9 subsequently underwent radical operation using a patch graft. Ultrasonic study showed several characteristic findings suggestive of the syndrome, and frequencies of the main findings were as follows: 1) an echogenic obstructing membrane; 22.2%, 2) segmental obstruction of the IVC; 77.8%, 3) occlusion of the major hepatic veins at the juxtacaval portion; 100%, 4) enlarged inferior right hepatic veins; 55.6%, 5) abnormal intrahepatic venous structures and collaterals; 88.9%. Of these findings, 5) was the most prominent and most characteristic in the diagnosis of the syndrome. It is necessary for early detection of this entity to evaluate carefully intrahepatic venous abnormalities and patency of either the IVC or major hepatic veins on ultrasonic examination. The careful examination for Budd-Chiari syndrome should be done in cases with cryptogenic liver cirrhosis, particularly in countries where the prevalence of the syndrome is high.

Membranous obstruction of the inferior vena cava with Budd-Chiari syndrome: MR imaging findings

Membranous obstruction of the inferior vena cava (IVC) is a curable cause of a primary type of Budd-Chiari syndrome. Magnetic resonance (MR) imaging and vena cavography were performed on nine patients with membranous obstruction of the IVC. The MR findings were retrospectively analyzed and compared with computed tomographic findings in seven patients. The morphologic features of membranous obstruction of the IVC on spin-echo MR images were a curvilinear soft-tissue membrane (five cases) or an obliterated lumen of a hepatic segment of the IVC (four cases) in transverse or sagittal views. The lumen below the obstruction revealed flow-related signal (seven cases), intraluminal thrombus (one case), and thrombotic occlusion (one case). The hepatic veins were narrow and disoriented without connection to the hepatic segment of the IVC just below the diaphragm. On T2-weighted images, inhomogeneity with high signal intensity was shown more prominently in the hepatic parenchyma in Simson type II or III membranous obstruction. Other findings were hepatosplenomegaly, enlarged caudate lobe, cirrhotic liver, associated hepatoma, and presence of various collaterals.

Diagnostic utility of ultrasonography in hepatic venous outflow tract obstruction in a tropical country

The present study was undertaken to define the role of ultrasonography (US) in screening and diagnosis of hepatic venous outflow tract obstruction. Forty-five consecutive patients clinically suspected to have hepatic venous outflow tract obstruction were included in the study for screening by US and for assessment of patency or block in the hepatic vein (HV) and/or inferior vena cava (IVC). Four patients were excluded from the study. Eleven patients had a diagnosis other than hepatic venous outflow tract obstruction and all these patients were found to have patent HV and IVC. Thirty patients were finally diagnosed to have hepatic venous outflow tract obstruction. Using US, as a screening test 27 (90%) out of 30 such cases were correctly identified as cases of hepatic venous outflow tract obstruction and in these cases the site of block in hepatic venous outflow tract (major HV and/or IVC) was correctly diagnosed in 90% of the cases. Our results indicate that US is a sensitive and accurate test and should be the initial investigation for screening and identifying the site of obstruction in patients with hepatic venous outflow tract obstruction.

Diagnosis of Budd-Chiari syndrome by pulsed Doppler ultrasound

Computed tomography and real-time ultrasonography may not be conclusive for the diagnosis of the Budd-Chiari syndrome; in many cases more information may be needed, especially on vascular alterations. Doppler ultrasonography provides qualitative data on flow direction and pattern, thereby contributing significantly to diagnosis. Eight cases in which hepatic vein patency was unclear and presence of intrahepatic vessels resembling hepatic veins raised problems of interpretation in real-time ultrasonography are described. In some cases, patency or occlusion of the upper portion of the inferior vena cava were difficult to identify with real-time ultrasonography. Doppler ultrasonographic investigation showed flow in the hepatic veins to be completely absent in two cases and reversed in another two. In the remaining four cases, a flat waveform was evident. Flow in the inferior vena cava was reversed in four cases and showed a flat waveform in three other cases. Portal vein thrombosis was detected in only one case, whereas the remaining seven patients showed slow hepatopetal flow. These findings demonstrate that absent or reversed flow in the hepatic veins and/or flat flow in the hepatic veins associated with reversed flow in the inferior vena cava may be considered diagnostic for the Budd-Chiari syndrome. For this series the sensitivity of Doppler ultrasonography was 87.5%.

Hepatic encephalopathy due to a large intrahepatic communication between the portal vein and inferior vena cava

A 59 year old man with cirrhosis presented with encephalopathy and hyper-ammonaemia. T1 weighted magnetic resonance imaging demonstrated a large void tubular structure connecting the right posterior portal vein branch and the inferior vena cava through the right hepatic lobe inferiorly, and cine-mode imaging showed a flow within this channel. Clearly in this patient a significant portion of the portal venous blood was being shunted into the inferior vena cava, causing encephalopathy. The exact origin of this channel is not known, but several possibilities are discussed. It is also predicted that similar previously unknown large intrahepatic shunts will be discovered increasingly with the availability of modern imaging techniques.

Hepatic vein thrombosis in Behçet's disease

We describe four patients with hepatic vein thrombosis caused by Behçet's disease and review the 17 previously published cases. In addition, we compared these 21 cases of hepatic vein thrombosis to our 24 cases of hepatic vein thrombosis caused by primary myeloproliferative disorders. In patients with Behçet's disease, a male predominance (male/female ratio, 19:1) contrasted with the female predominance found in patients with hepatic vein thrombosis complicating primary myeloproliferative disorders (sex ratio = 1:3). The mean age at clinical onset was younger in patients with Behçet's disease than in those with primary myeloproliferative disorders (29 vs. 35 yr). Obstruction of the inferior vena cava was found in 90% of patients with hepatic vein thrombosis caused by Behçet's disease. Inferior vena caval thrombosis appears to be the main pathophysiological mechanism of hepatic vein thrombosis in patients with Behçet's disease. Unlike patients with primary myeloproliferative disorders who often had a progressive course, one third of patients with Behçet's disease had acute liver failure and died within 2 wk of clinical onset. These findings suggest that, in patients with Behçet's disease, hepatic vein thrombosis is a sudden event usually related to the extension of a caval thrombus to the ostium of the hepatic veins.

Comparison of ultrasonography, computed tomography and 99mTc liver scan in diagnosis of Budd-Chiari syndrome

Ultrasonography, computed tomography and 99mTc liver scanning are all useful in diagnosis of patients with the Budd-Chiari syndrome. In a study to determine their comparative value characteristic findings were recorded in all nine patients at ultrasonography and in seven patients at computed tomography. In contrast 99mTc liver scan showed a characteristic pattern in only one of eight patients. In our experience intrahepatic venous abnormalities were seen better at ultrasonography than at computed tomography. In addition, abnormality in the direction of blood flow could be detected by pulsed Doppler examination. Ultrasonography is relatively inexpensive, readily accessible, does not require administration of radiation or contrast agents and therefore should be the primary non-invasive investigation of patients with Budd-Chiari syndrome, or those at risk of developing it.

Magnetic resonance imaging diagnosis of Budd-Chiari syndrome

Noninvasive imaging modalities may suggest the diagnosis of Budd-Chiari syndrome but they are rarely diagnostic. Inferior vena cavography, hepatic venography, and liver biopsy, alone or in combination, are usually necessary for definitive diagnosis. Because of its excellent depiction of blood vessels as regions of absent signal, magnetic resonance imaging has the potential to make a noninvasive diagnosis of hepatic vein thrombosis. A case illustrating the usefulness of magnetic resonance imaging in the diagnosis of Budd-Chiari syndrome is presented.

Membranous obstruction of the inferior vena cava associated with intrahepatic portosystemic shunt

Two cases of membranous obstruction of the IVC at hepatic portion associated with intrahepatic portosystemic shunts, which presumably represent the persistent vitelline sinusoids, are presented. The association of these two conditions has not been previously reported and may support the congenital etiology of the membranous obstruction of the IVC. The caval membrane was successfully dilated percutaneously with a balloon catheter in each case.

Therapeutic hepatic vein angioplasty for Budd-Chiari syndrome

The authors report a case of Budd-Chiari syndrome treated by percutaneous transluminal angioplasty (PTA). In this case, the occlusion of three major hepatic veins with a big collateral to the inferior vena cava via the right inferior hepatic vein (RIHV) and stenosis of the ostium of RIHV were seen. We performed successful PTA of this stenosis.

Risk of hepatic vein thrombosis in relation to recent use of oral contraceptives. A case-control study

In a case-control study, we evaluated the relative risk of hepatic vein thrombosis among recent oral contraceptive users as compared with nonusers. Thirty-three cases of hepatic vein thrombosis affecting women aged 15-45 yr were collected between 1970 and 1983, and individually matched to 3 or 4 controls interviewed in 1982-1984. There were 18 recent oral contraceptive users among the 33 cases, and 44 recent oral contraceptive users among the 128 case-matched controls. The relative risk of hepatic vein thrombosis was 2.37 (95% confidence interval: 1.05-5.34, p less than 0.02). The relative risk of hepatic vein thrombosis is close to that of stroke, myocardial infarction, and venous thromboembolism among oral contraceptive users as compared with nonusers.

Hepatic vein occlusion: morphologic features on computed tomography and ultrasonography

Hepatic vein occlusion causes morphologic changes that can be demonstrated by computed tomography (CT) and ultrasound. In this study the imaging findings of acute, subacute, and chronic occlusion of the hepatic veins were analyzed retrospectively in 9 patients and correlated with the histopathologic changes. The CT findings were focal or scattered hypodense parenchymal lesions of the liver before and a patchy enhancement after intravenous bolus injection of contrast material. In none of the cases could the hepatic veins be identified. Hepatomegaly with relative enlargement of the caudate lobe was almost always observed. Ultrasonography demonstrated solid material within the major hepatic veins, intrahepatic venous collaterals, and focal parenchymal lesions, which varied with the stage of the disease: a hypoechogenic area was observed in acute hepatic vein thrombosis with subsequent hemorrhagic infarction; hyperechogenic lesions corresponded with fibrotic zones in chronic disease. Ascites was shown by both methods in all patients.

Portal vein thrombosis: real-time sonographic demonstration and follow-up

Twelve patients with portal vein thrombosis (PVT) associated with various disorders were examined. In 11 the diagnosis of PVT was made primarily by ultrasound. Endovenous lesions that presented with a mainly homogenous texture pattern of different echodensity could be clearly displayed, but failed to disclose specific echographic features that allow conclusive discrimination between blood clots (n = 7; mean diameter 13 +/- 1.7 mm) and venous tumor invasion (n = 5; mean diameter 24 +/- 12 mm). Thrombus resolution on therapy as well as cavernous transformation of the portal vein following acute PVT may be visualized by serial sonograms. Secondary findings in PVT that can be displayed by sonography include splenomegaly and superior mesenteric vein obstruction with intestinal ischemia. Real-time sonography has proved to be a valuable noninvasive method for the early diagnosis and follow-up of PVT.