Can we delineate preoperatively the right and ventral margins of caudate lobe of the liver?

Abstract

Purpose: Complete removal of the caudate lobe, which is sometimes necessary, is accomplished via isolated caudate lobectomy or hepatectomy that includes the caudate lobe. It is impossible, however, to confirm the right and ventral margins of the caudate lobe by preoperative imaging. This study was undertaken to determine whether we could identify the right and ventral margins of the caudate lobe preoperatively using Synapse 3D visualization software.

Methods: Ninety-four preoperative 3-dimensional (3D) computed tomographic images (1-mm slices) of the liver from candidate donors were examined. The images of the caudate lobe were subjected to a counter-staining method according to Synapse 3D to delineate their dimensions. We first examined whether the right margin of the caudate lobe exceeded the plane formed by the root of the right hepatic vein (RHV) and the right side of the inferior vena cava (IVC). Second, we determined whether the ventral margin of the caudate lobe exceeded the plane formed by the root of the middle hepatic vein (MHV) and the root of the RHV.

Results: For the right margin, 17 cases (18%) exceeded the RHV-IVC plane by a mean of 10.2 mm (range, 2.4-27.2 mm). For the ventral margin, 28 cases (30%) exceeded the MHV-RHV plane by a mean of 17.4 mm (range, 1.2-49.1 mm).

Conclusion: Evaluating the anatomy of caudate lobe using Synapse 3D preoperatively could be helpful for more precise anatomical resection of the caudate lobe.

Keywords: Caudate lobe of liver; Liver anatomy; Preoperative; Three-dimensional imaging.

Fig. 1. The caudate parenchyma was delineated using a counter-staining technique. Hepatic veins, hepatic arteries, and bile ducts are hidden to identify images more easily. (A) By hiding the hepatic parenchyma, the portal vein branch of the paracaval portion can be seen (star). (B) By clicking on the portal vein branch of the paracaval portion, the parenchyma of caudate lobe is shown (yellow). (C) In the same case, we clicked on the left portal vein (square), right anterior portal vein (circle), and right posterior portal vein (diamond), respectively, which then showed the corresponding parenchyma of the liver. (D) The shape of the remnant liver parenchyma is the same as in panel B.

Fig. 2. The methods to define the right and ventral margins are shown. (A) IVC and RHV can be identified after hiding the hepatic parenchyma other than the caudate lobe. (B) RHV-IVC plane can be seen (translucent brown) by connecting the RHV from the root + 3 cm and the right border of the IVC. (C) RHV-IVC plane can be seen (yellow) by connecting the RHV from the root + 3 cm and the right border of the IVC. (D) MHV and RHV can be identified after hiding the hepatic parenchyma. (E) MHV-RHV plane can be seen (translucent yellow) by connecting the MHV from the root + 3 cm and RHV from the root + 3 cm. (F) MHV-RHV plane can be seen (yellow) by connecting the MHV from the root + 3 cm and RHV from the root + 3 cm. IVC, inferior vena cava; RHV, right hepatic vein; MHV, middle hepatic vein.

Fig. 3. Right and ventral margins of the caudate lobe are shown. The relations between the caudate lobe and right hepatic vein and inferior vena cava (RHV-IVC) plane and the middle and right hepatic veins (MHV-RHV) plane is shown in Synapse 3-dimensional images. (A) Caudate lobe is located on the right side of the RHV-IVC plane (yellow). (B) The parenchyma of the caudate lobe exceeds the RHV-IVC plane (yellow) is outlined in red. We calculated that the distance exceeds the right margin is 5.6 mm in this case. (C) Caudate lobe is ventrally located in the MHV-RHV plane (yellow). (D) The parenchyma of the caudate lobe exceeds the MHV-RHV plane (yellow) is outlined in red. We calculated that the distance exceeds the ventral margin is 10.6 mm. IVC, inferior vena cava; RHV, right hepatic vein; MHV, middle hepatic vein.