Inferior Vena Cava Type Research Articles

Variants of the Inferior Vena Cava

Abstract Abnormalities of the inferior vena cava (IVC) and its tributaries are rare anomalies detected more frequently by computed tomography scans with intravenous contrast. Its importance lies in identifying them by the possible clinical and surgical implications. They originate from the persistence or regression of the three embryonic veins (posterior cardinal, subcardinal, and supracardinal) and their anastomosis. There are three cases, the first with double IVC type I, which has a prevalence of 0.2%–3%. The second case has a left vena cava, which has a 0.2%–0.5% prevalence. The third case is with retroaortic left renal vein, which has a prevalence of 3.4%.

Budd-Chiari Syndrome: The “inferior vena cava reverse-flow” sign and “jet-blood” sign on CT and MRI

ObjectiveTo investigate the CT and MR features of “inferior vena cava(IVC) reverse-flow” sign and “jet-blood” sign in Budd-Chiari Syndrome (BCS). MethodsThe liver CT and/or MRI plain scan and dynamic enhancement of 107 cases of BCS diagnosed by DSA and/or clinic were collected, including 17 patients with hepatic vein obstruction type, 79 patients with IVC obstruction type, and 11 patients with mixed type. The manifestations of IVC reverse-flow sign and jet-blood sign in the latter two type BCS (90cases) imaging were analyzed. Results1) The incidence of IVC reverse-flow sign in the IVC obstruction type and mixed type was 93.3 %(83/90), which was manifested as: The contrast agent was shown below the level of renal veins in the hepatic arterial phase enhancement, while no contrast agent was shown above it at the same time. 2) The incidence of jet-blood sign in membrane-perforated subtype was 100 %(15/15) or 16.7 %(15/90), which was manifested as: The low density/signal dots appeared within full of contrast agent at the superior liver segment IVC on axial slices in arterial phase of CT/MRI enhancement, or the low signal line within agent presented above the IVC membrane on coronal image in equilibrium phase of MR enhancement. 3) Other imaging findings: 75 cases of membrane, 18 cases of membrane calcification, 27 cases of abnormal hepatic vein, 76 cases of abnormal structure of IVC, 18 cases of thrombus/cancer embolus in hepatic vein and/or IVC. There were 65 cases of abnormal liver appearance; 71 cases of abnormal liver enhancement; 21 cases of hepatic vein unsynchronous enhancement. Anastomotic branches among the hepatic veins open with comma sign in 54 cases; dilatation of intraspinal and paravertebral veins, azygos and hemiazygos veins in 90 cases(100 %, 90/90) or 96 cases(89.7 %, 96/107). ConclusionsThe “IVC reverse-flow” sign is a specific CT and MR sign of IVC type and mixed type BCS, and the “jet-blood” sign is a characteristic CT and MR sign of membrane-perforated subtype BCS.

Effects of low-dose energy spectrum scanning combined with adaptive statistical iterative reconstruction on the quality of imaging in Budd-Chiari syndrome.

ObjectiveTo assess the quality and diagnostic accuracy of monochromatic images combined with adaptive statistical iterative reconstruction (ASIR) performed via spectral computed tomography (CT) in patients with Budd-Chiari syndrome (BCS).MethodsSixty-two patients with BCS underwent pectral CT with upper abdominal two-phase contrast-enhanced scanning to generate a 60keV monochromatic energy level combined with ASIR (ranging from 0% -100%) during the portal venous phase (PVP) and the hepatic venous phase (HVP). One-way ANOVA was used to compare vessel-to-liver contrast-to-noise ratio (CNR) for the portal vein (PV), hepatic vein (HV), and inferior vena cava (IVC). Subjective evaluations of the images in the three groups were conducted by image quality assessors and compared via Kruskal-Wallis H test.ResultsThe CNR values of the PV trunk, HV, IVC, liver parenchyma and pancreas were within ASIR (ranging from 0% - 100%) weight, and the difference were statistically significant (p <0.05). The highest overall image score was distributed at 50% ASIR weight value. Higher CNR values of HV, hepatic parenchyma and pancreas were obtained in the IVC type than in mixed and HV types (respective p values = 0.035, 0.019 and 0.042). Higher CNR values of the IVC were obtained in the HV type than in mixed and IVC types (p = 0.032). The CNR value of the IVC in the mixed type was less than that of the HV type (p = 0.028). The CNR values of the HV and liver parenchyma in mixed type were lower than those of the IVC type (p = 0.016 and 0.038, respectively). The CNR value of pancreas in IVC type was higher than that of the HV type (p = 0.037). The diagnostic value of CNR in patients with the IVC type was higher than that in patients with mixed and HV type, while the diagnostic value of CNR was found to be the lowest for the HV type (p = 0.043).ConclusionA monochromatic energy level of 60 keV with 50% ASIR can significantly improve image quality in cases of BCS.

Iatrogenic diversion of IVC to left atrium after surgical closure of ASD

Iatrogenic diversion of the inferior vena cava (IVC) to the left atrium during surgical closure of an atrial septal defect (ASD) is a very rare complication in the era of cardiopulmonary bypass. The eustachian valve could be mistaken for the margin of the ASD. We report a case with this complication after closure of a sinus venosus ASD of the IVC type.

To restrict indication for stenting of the inferior vena cava and liver transplantation in patients with Budd-Chiari syndrome

The Budd-Chiari syndrome (BCS) used to be a very rare disorder and lacked a means of relieving. However, various shuntings and radical procedures have emerged in the last three decades with quite encouraging outcomes. Recent minimally invasive therapies, such as stenting of the inferior vena cava (IVC), are simple and easy to handle. However, it has been realized that the IVC stent may compromise the hepatic veins and cause catastrophic consequences, thus the indication for IVC stenting should be reevaluated and especially not to be overused. Instead, it should be applied by percutaneous transangiography (PTA) only, which may be repeated when necessary. The BCS in China predominantly belongs to the IVC type rather than the intrahepatic type in Western; the outcome from its conventional therapy, at least for the moment, is better than that of liver transplantation. It is thus suggested that, before liver transplantation is decided, the conventional means for managing BCS be considered. The final suggestion is to restrict the indication both for stenting of the IVC and liver transplantation. In this paper, ten examples are given with figures.