Anatomy of retrohepatic segment of inferior vena cava and termination of hepatic veins

Gravity assistance enables liver stiffness measurements to detect liver fibrosis under congestive circumstances

BACKGROUND

As survival has been prolonged owing to surgical and medical improvements, liver failure has become a prognostic determinant in patients with congestive heart diseases. Congestive hepatopathy, an abnormal state of the liver as a result of congestion, insidiously proceed toward end-stage liver disease without effective biomarkers evaluating pathological progression. Regular measurements of shear wave elastography cannot qualify liver fibrosis, which is a prognosticator in any type of chronic liver disease, in cases of congestion because congestion makes the liver stiff without fibrosis. We hypothesized that the effects of congestion and fibrosis on liver stiffness can be dissociated by inducing architectural deformation of the liver to expose structural rigidity.

AIM

To establish a strategy measuring liver stiffness as a reflection of architectural rigidity under congestion.

METHODS

Two-dimensional shear wave elastography (2dSWE) was measured in the supine (Sp) and left decubitus (Ld) positions in 298 consecutive cases as they were subjected to an ultrasound study for various liver diseases. Regions of interest were placed at twelve sites, and the median and robust coefficient of variation were calculated. Numerical data were compared using the Mann-Whitney U or Kruskal-Wallis test followed by Dunn's post-hoc multiple comparisons. The inferior vena cava (IVC) diameters at different body positions were compared using the Wilcoxon matched pairs signed rank test. The number of cases with cardiothoracic ratios greater than or not greater than 50% was compared using Fisher's exact test. A correlation of 2dSWE between different body positions was evaluated by calculating Spearman correlation coefficients.

RESULTS

The IVC diameter was significantly reduced in Ld in subjects with higher 2dSWE values in Ld (LdSWE) than in Sp (SpSWE) (P = 0.007, (average ± SD) 13.9 ± 3.6 vs 13.1 ± 3.4 mm) but not in those with lower LdSWE values (P = 0.32, 13.3 ± 3.5 vs 13.0 ± 3.5 mm). In 81 subjects, SpSWE was increased or decreased in Ld beyond the magnitude of robust coefficient of variation, which suggests that body postural changes induced an alteration of liver stiffness significantly larger than the technical dispersion. Among these subjects, all 37 with normal SpSWE had a higher LdSWE than SpSWE (Normal-to-Hard, SpSWE - LdSWE (∆2dSWE): (minimum-maximum) -0.74 - -0.08 m/sec), whereas in 44 residual subjects with abnormal SpSWE, LdSWE was higher in 27 subjects (Hard-to-Hard, -0.74 - -0.05 m/sec) and lower in 17 subjects (Hard-to-Soft, 0.04 - 0.52 m/sec) than SpSWE. SpSWE was significantly correlated with ∆2dSWE only in Hard-to-Soft (P < 0.0001). ∆2dSWE was larger in each lobe than in the entire liver. When Hard-to-Hard and Hard-to-Soft values were examined for each lobe, fibrosis-4 or platelet counts were significantly higher or lower only for Hard-to-Soft vs Normal-to-Hard cases.

CONCLUSION

Gravity alters the hepatic architecture during body postural changes, causing outflow blockage in hepatic veins. A rigid liver is resistant to structural deformation. Stiff-liver softening in the Ld position suggests a fibrous liver.

Reconstruction of Inferior Right Hepatic Veins in Living Donor Liver Transplantation

BACKGROUND

A proper knowledge of the anatomy of the liver (including its vascular particularities) is mandatory in cases which are going to be submitted to major hepatic resection, including living donor liver transplantation.

CASE REPORT

We present the case of a living donor liver transplantation in which a particularity of the anatomy of the hepatic veins was reported for the donor: two inferior hepatic veins for segments 5 and 6. This particularity imposed the need for creation of a supplemental anastomosis in the recipient: a phleboplasty of the two inferior veins followed by direct re-implantation into the inferior cava vein. However, the postoperative course was uneventful for both the donor and the recipient.

CONCLUSION

In certain cases presenting vascular particularities such as two inferior hepatic veins, phleboplasty followed by reimplantation into the inferior cava vein might be needed in order to provide a good vascular outflow of the liver graft.

Is the absence of Right Hepatic Vein opening into Inferior Vena Cava a contraindication for right lobe liver donation in Living Donor Liver Transplantation? Common hepatic venous trunk-A rare hepatic vein anomaly: A case report and review

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A rare hepatic venous variation in the voluntary liver donor and the surgical challenge faced by the transplant surgeon.

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Review of the variations of hepatic venous drainage and their significance in the context of living donor liver transplantation.

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Surgical maneuver employed in dealing with such a rare variation of hepatic vein in the living donor.

Introduction

In majority of the living liver donors, the left and the middle hepatic veins form a common trunk and the right hepatic vein drains by a separate trunk into the IVC forming two ostial openings. Presentation of Case: This report presents a rare challenge to the operating surgeon in which the three major hepatic veins form a common trunk and drain into the IVC through a single ostial opening. It was detected preoperatively by the routine donor imaging studies.

Discussion

To our knowledge, this type of rare venous anatomy in the setting of living donor liver transplantation has not been described in the literature before. A few studies have described similar anatomy in the cadaveric liver specimen of some particular ethnicity.

Conclusion

This type of a rare anomaly poses challenge to the donor operation and requires a sound expertise on the knowledge of hepatic venous anatomy to perform the donor hepatectomy with the appropriate maneuvering.