Altered hepatic hemodynamics caused by temporary occlusion of the right hepatic vein: evaluation with Doppler US in 14 patients

Partial Hepatic Vein Occlusion and Venous Congestion in Liver Exploration Using a Hyperspectral Camera: A Proposal for Monitoring Intraoperative Liver Perfusion

INTRODUCTION

The changes occurring in the liver in cases of outflow deprivation have rarely been investigated, and no measurements of this phenomenon are available. This investigation explored outflow occlusion in a pig model using a hyperspectral camera.

METHODS

Six pigs were enrolled. The right hepatic vein was clamped for 30 min. The oxygen saturation (StO₂%), deoxygenated hemoglobin level (de-Hb), near-infrared perfusion (NIR), and total hemoglobin index (THI) were investigated at different time points in four perfused lobes using a hyperspectral camera measuring light absorbance between 500 nm and 995 nm. Differences among lobes at different time points were estimated by mixed-effect linear regression.

RESULTS

StO₂% decreased over time in the right lateral lobe (RLL, totally occluded) when compared to the left lateral (LLL, outflow preserved) and the right medial (RML, partially occluded) lobes (p < 0.05). De-Hb significantly increased after clamping in RLL when compared to RML and LLL (p < 0.05). RML was further analyzed considering the right portion (totally occluded) and the left portion of the lobe (with an autonomous draining vein). StO₂% decreased and de-Hb increased more smoothly when compared to the totally occluded RLL (p < 0.05).

CONCLUSIONS

The variations of StO₂% and deoxy-Hb could be considered good markers of venous liver congestion.

Color Doppler Intraoperative Ultrasonography Evaluation of Hepatic Hemodynamics for Laparoscopic Parenchyma-Sparing Liver Resections

BACKGROUND

Tumors involving the hepatic veins at the hepatocaval confluence often require major or extended hepatectomies. Color Doppler intraoperative ultrasonography (CD-IOUS) evaluation of liver hemodynamics to assess congestion in the veno-occlusive parenchyma provides real-time information helpful in parenchyma-sparing surgery (PSS). This study evaluated the feasibility of CD-IOUS in patients undergoing laparoscopic liver resections for such tumors and its capacity to allow PSS.

METHODS

Consecutive patients undergoing laparoscopic liver resection for tumors at the hepatocaval confluence requiring resection of at least one hepatic vein between January 2010 and August 2020 were included. Patients were divided in 3 groups: (A) patients not assessed with CD-IOUS because it would not change the scheduled operation; patients assessed with CD-IOUS and treated with (B) PSS and (C) no-PSS. Portal blood flow in the veno-occlusive parenchyma was assessed using CD-IOUS at baseline and after clamping the concerned hepatic vein.

RESULTS

The study included 43 out of 47 patients with tumors at the hepatocaval confluence. There were 19 patients in group A. Among patients assessed with CD-IOUS, the resection of 26 hepatic veins was planned: 25 were resected, and 1 was spared. Group B included 22 patients treated with PSS, whereas group C included 2 patients with resection of all veno-occlusive parenchyma. No postoperative mortality or major morbidity was observed. The median length of hospital stay was 5 days.

CONCLUSIONS

Selected patients with tumors involving the hepatocaval confluence can be safely approached using laparoscopy. CD-IOUS evaluation of the veno-occlusive area can increase the success rate of PSS.

Hepatic Arterioportal Fistulas: A Retrospective Analysis of 97 Cases

BACKGROUND AND AIMS

Hepatic arterioportal fistulas (HAPFs) are abnormal shunts or aberrant functional connections between the portal venous and the hepatic arterial systems. Detection of HAPFs has increased with the advances in diagnostic techniques. Presence of HAPFs over a prolonged period can aggravate liver cirrhosis and further deteriorate liver function. However, the underlying causes of HAPFs and the treatment outcomes are now well characterized. This study aimed to summarize the clinical characteristics of patients with HAPFs, and to compare the outcomes of different treatment modalities.

METHODS

Data of 97 patients with HAPFs who were admitted to the Second Xiangya Hospital between January 2010 and January 2020 were retrospectively reviewed. Demographic information, clinical manifestations, underlying causes, treatment options, and short-term outcomes were analyzed.

RESULTS

The main cause of HAPF in our cohort was hepatocellular carcinoma (78/97, 80.41%), followed by cirrhosis (10/97, 10.31%). The main clinical manifestations were abdominal distention and abdominal pain. Treatment methods included transcatheter arterial embolization (n=63, 64.9%), surgery (n=13, 13.4%), and liver transplantation (n=2, 2.1%); nineteen (19.6%) patients received conservative treatment. Among patients who underwent transcatheter arterial embolization, polyvinyl alcohol, lipiodol combined with gelatin sponge, and spring steel ring showed comparable efficacy.

CONCLUSIONS

Hepatocellular carcinoma and cirrhosis are common causes of HAPFs. Transcatheter arterial embolization is a safe and effective method for the treatment of HAPFs, and polyvinyl alcohol, lipiodol combined with gelatin sponge, and spring steel ring showed comparable efficacy in our cohort.

Long-term follow-up study in Budd-Chiari syndrome: single-center experience in 22 years

GOALS

We aimed to present our long-term surveillance experience in patients with Budd-Chiari syndrome (BCS), and we retrospectively evaluated the natural history, results of thrombophilia studies, and the factors related to mortality.

BACKGROUND

Primary BCS is a rare form of vascular disease, secondary to underlying thrombophilia. Because of its rarity and heterogeneous nature, there is a scarcity of knowledge about the natural history of the disease.

STUDY AND RESULTS

In 22 years, a total of 62 patients with primary BCS were followed in our tertiary hospital. We identified an acquired cause of BCS in 40 out of 62 patients (64.5%), whereas in 6 patients (9.7%), we found no identifiable cause. One or more thrombophilia causes were identified in 56 patients (90.3%). In 19 patients with myeloproliferative disease, 15 had Janus tyrosine kinase 2 mutation analysis and Janus tyrosine kinase 2 positivity was found in 10 patients. In regression analysis, portal vein thrombosis was found to be the only indicator of mortality, with an estimated instantaneous risk of 8.4.

CONCLUSIONS

In this study, we present one of the largest series of BCS in the English literature. We have shown that the multifactorial nature of underlying thrombophilia should be thoroughly investigated. In a patient with BCS, a clinician should be alert for the development or coexistence of portal vein thrombosis due to its deleterious effect on mortality.

Detection of intrahepatic veno-venous shunts by three-dimensional venography using multidetector-row computed tomography during angiography

PURPOSE

The hepatic vein (HV) can be removed during hepatectomy if there is an effective intrahepatic veno-venous shunt (vv-shunt). We evaluated the efficacy of vv-shunt detection by three-dimensional (3D) venography reconstructed from multidetector-row computed tomography (MDCT) during angiography.

METHODS

3D venography was reconstructed using computer software in 88 patients with intrahepatic tumors.

RESULTS

We found that 12 patients had one shunt [4 right hepatic vein (RHV)-middle hepatic vein (MHV) and 12 RHV- inferior right hepatic vein (IRHV)] and 1 patient had 2 shunts (RHV-MHV and -IRHV), confirming a clinically efficient vv-shunt in 14.8% of the patients. In one patient with an RHV-IRHV shunt, the preserved RHV-IRHV shunt worked well and prevented congestion of the postero-caudal subsegment after central bisegmentectomy with partial resection of the RHV ventral trunk for huge hepatocellular carcinoma (HCC).

CONCLUSIONS

Although the vv-shunt detection rate by 3D venography is low, a visualized vv-shunt proved to be efficient. Thus, invasive occlusion venography is avoidable if a vv-shunt is seen on 3D venography.

Hepatic venous occlusion during cardiopulmonary bypass in patients with heterotaxy syndrome: a safe but underutilized option

Direct intracardiac drainage of separate right and left hepatic veins remote from each other (independent hepatic veins) in heterotaxy patients complicates procedures requiring cardiopulmonary bypass (CPB). Temporary occlusion of such independent hepatic veins during CPB is an alternative to cannulation but is rarely used because of concerns about acute congestive hepatopathy. Consequently, temporary single hepatic venous occlusion has not been well described as a safe and simple alternative to hepatic venous cannulation during CPB. We report 2 patients with the polysplenia variant of heterotaxy in whom independent hepatic veins were safely occluded for 55 and 86 minutes, respectively, in the course of intracardiac repair. Temporary hepatic venous occlusion simplified the CPB technique and minimized clutter of the operative field. The intrahepatic hemodynamics during CPB using temporary hepatic venous occlusion is illustrated.

Takao Hiraki’s work on interventional radiology

Dr. Takao Hiraki is a scientist carrying out interventional radiology research in the Department of Radiology at Okayama University Medical School, Japan. He has conducted animal and human clinical studies on interventional radiology for various conditions. For example, he clarified the hepatic hemodynamic changes caused by hepatic venous occlusion. He also developed new devices, such as hydrogel coils for the occlusion of the aneurismal sac after an endovascular stent-graft of an aortic aneurysm to prevent endoleakage and small intestinal submucosa-covered stents for transjugular intrahepatic portosystemic shunts. Further, he performed a number of studies on the radiofrequency ablation of lung cancer, mediastinal lymph node metastasis, and computed tomography-fluoroscopy-guided lung biopsies. He intends to continue to dedicate his academic career to expand the role of interventional radiology in clinical medicine.

Radiological assessment of hepatic vein invasion by hepatocellular carcinoma using combined computed tomography hepatic arteriography and computed tomography arterial portography

PURPOSE

The aim of this study was to elucidate computed tomography hepatic arteriography (CTHA) and CT arterial portography (CTAP) findings characteristic of hepatocellular carcinoma (HCC) with large hepatic venous invasion (HVI) and then to examine whether the presence of minute HVI can be diagnosed based on each finding.

MATERIALS AND METHODS

Combined CTHA and CTAP of 106 HCCs were examined. Two radiologists analyzed the radiological findings of five nodules with large HVI (group vv2). The remaining 101 nodules were classified into two groups: group vv1, positive minute HVI; group vv0, negative HVI. They examined whether each finding observed in group vv2 could be detected in groups vv1 and vv0.

RESULTS

Analysis of group vv2 identified (a) tumor thrombus, (b) early inflow of the contrast into the hepatic vein proximal to the invaded site, and (c) partially decreased portal venous flow in the peripheral parenchyma subject to the involved hepatic vein. Findings (b) and (c) were observed in 16% of group vv1. A significant difference in frequency of finding (c) was obtained between groups vv1 and vv0. The positive and negative predictive values of finding (c) were 66.7% and 77.9%, respectively.

CONCLUSION

Findings (b) and (c), especially the latter, may partly contribute to the radiological diagnosis of minute HVI.

Analysis of intrahepatic venovenous shunt by hepatic venography

BACKGROUND

The necessity of preserving hepatic venous drainage in hepatectomy and liver transplantation has recently been accepted; however, the hepatic vein (HV) can be removed when an effective intrahepatic venovenous shunt (VV shunt) exists.

METHODS

Occlusion venography of the right HV (RHV) was performed in 51 patients to investigate the VV shunt characteristics.

RESULTS

Twenty patients had a shunt between the RHV and large HVs whose root diameters were >3 mm, such as the superficial or inferior RHV, or the middle HV. Twenty patients had a shunt between the RHV and small HVs with root diameters < or =3 mm. Eleven patients had no shunt. The change in anterior portal vein blood flow after RHV occlusion, evaluated by Doppler ultrasonography, was minimal (5 +/- 3%) in patients with a shunt between the RHV and large HVs, and less than in patients with a shunt between the RHV and small HVs (38% +/- 18%) or without a shunt (50% +/- 17%; P < .0001). A shunt between the RHV and large HV was less frequently seen in those patients with cirrhosis (3/20) than in those without cirrhosis (17/31; P = .0044). The existence of the shunt between the RHV and large HVs was unpredictable, however, from computed tomographic findings or laboratory data.

CONCLUSION

A hemodynamically significant VV shunt between the RHV and large HV was observed in fewer than half of the patients and less frequently in cirrhotic patients. Preservation of hepatic venous drainage should be considered in patients without a hemodynamically significant VV shunt in liver surgery.

Early changes of the portal tract on microcomputed tomography images in a newly-developed rat model for Budd-Chiari syndrome

BACKGROUND AND AIM

The effect of increased sinusoidal pressure on the portal tract in Budd-Chiari syndrome (BCS) is as yet not elucidated. Our aim was to investigate portal changes in a newly-developed rat model for BCS.

METHODS

We created an outflow obstruction in Sprague-Dawley rats (n = 6) by diameter reduction of the inferior vena cava. Left and right liver lobes with portal vein contrast were scanned using microcomputed tomography, and volumes of the portal tree and liver parenchyma were computed by the ANALYZE software program.

RESULTS

Portal branching density was significantly lower in BCS than the shams, and decreased over time (P < 0.01). There was a significant drop in volume of both parenchyma and the portal tree in the left but not right lobes. At 6 weeks post-surgery, the perfusion index (i.e. ratio between both volumes) became equal to (left) or even higher than (right) the shams, suggesting a new equilibrium with preserved portal perfusion. Histological findings were consistent with those observed in humans.

CONCLUSION

As early as day 2, a significant loss of peripheral portal branches was seen, which progressed over time. Inter-lobar differences in vascular abnormalities suggest compensatory mechanisms. Despite a decrease in both liver and portal vein volume, relative portal perfusion appeared spared.

Advances in imaging diagnosis of Budd-Chiari syndrome

Budd-Chiari syndrome (BCS) is very easy to be misdiagnosed due to the lack of specificity in clinical manifestation. With the improvement of multiple imaging diagnostic devices and methods, the detection rate of BCS is raised. The noninvasive imaging examination methods, such as ultrasound, multi-slice computed tomography (MSCT), magnetic resonance imaging (MRI), are able to clearly display hepatic vein (HV), inferior vena cave (IVC), and the location and type of stenosis. Therefore, they are useful for the clinical treatment and result observation.

Hepatic Venous Congestion After Right-lobe Living-donor Liver Transplantation

PURPOSE

To describe and determine the additional value of delayed-phase imaging of hepatic venous congestion after living-donor liver transplantation.

MATERIALS AND METHODS

Twenty-eight patients who had surgical ligation of the middle hepatic vein (HV) in living-donor liver transplantation underwent 3-phase computed tomography scans. Two radiologists analyzed in consensus the presence and pattern of the hepatic attenuation difference and the opacification of the HV in the congested areas of the liver during each phase of the initial and follow-up computed tomography scanning. The imaging findings were correlated with the serum bilirubin level.

RESULTS

Opacification of the HV was observed more frequently in 22 (92%) of 24 hyperattenuating areas on delayed-phase (DP) scans than in 2 (50%) of 4 hypoattenuating areas in the congested areas of the liver. Patients with persistent hypoattenuatation in the congested areas on all phases (14%) showed significantly persistent hyperbilirubinemia after postoperative 4 weeks and showed a higher mortality rate (50%) than did the other patients with hyperattenuation on DP scans.

CONCLUSIONS

A hypoattenuating area of the liver during DP scans indicates severe hepatic congestion and is correlated with hyperbilirubinemia and a high mortality rate.

Doppler study of hepatic vein in cirrhotic patients: Correlation with liver dysfunction and hepatic hemodynamics

AIM: To elucidate the significance of Doppler measurements of hepatic vein in cirrhotic patients and to correlate with liver dysfunction and hepatic hemodynamics.

METHODS: One hundred patients with liver cirrhosis and 60 non-cirrhotic controls were studied. Doppler waveforms were obtained from right hepatic vein and flow velocity measured during quiet respiration. Doppler measurements were also obtained from portal trunk, right portal vein and proper hepatic artery.

RESULTS: Hepatic vein waveforms were classified into three classical patterns. Flat waveform was uncommon. Mean hepatic vein velocity was significantly higher in cirrhotic patients (12.7 ± 6.4 vs 5.1 ± 2.1 and 6.2 ± 3.2 cm/s; P < 0.0001). The poorer the grade of cirrhosis, the higher was the mean velocity. Maximum forward velocity was never greater than 40 cm/s in controls. Degree of ascites was found to be highly correlated with mean velocity. “Very high” group (≥ 20 cm/s) presented clinically with moderate to massive ascites. Correlations between right portal flow and mean velocity was significant (P < 0.0001, r = 0.687).

CONCLUSION: Doppler waveforms of hepatic vein, which is independent of liver dysfunction, should be obtained during normal respiration. Mean hepatic vein velocity reflects the change in hepatic circulation associated with progression of liver cirrhosis. It can be used as a new parameter in the assessment of liver cirrhosis.

Hepatic arterioportal shunts: dynamic CT and MR features

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