Deportalization, Venous Deprivation, Venous Congestion

Overview

Patients with multiple primary or secondary liver tumors have a low survival rate unless they can benefit from curative extended hepatic resections with R0 or R1 marge resection. Post-operative acute liver failure may occur after such surgery when the remnant liver is insufficient, leading to high morbimortality. The future remnant liver (FRL) preoperative evaluation is then the key consideration before performing extended liver resection. The FRL volume measurement on computed tomography (CT) imaging is the most widespread method of FRL evaluation. Threshold values of acceptable FRL volume depend on the underlying liver function, it ranges from 20-30% in healthy liver to 40% in cirrhotic liver. However, it recently appeared that the FRL function would be more valuable in predicting post-operative liver failure. 99mTc-mebrofenin hepatobiliary scintigraphy (HBS) combined with SPECT/CT enables reliable FRL function measurement with a threshold value calculated at 2.69%/min/m2, to predict post-hepatectomy liver failure. When the FRL evaluation does not reach the acceptable threshold values to avoid liver failure, portal vein embolization (PVE), consisting of portal branches occlusion of the future removed liver, can be performed. It is now the standard of care to induce FRL regeneration before surgery. Right PVE induces right hemiliver (S5-8) deportalization (portal input deprivation with hepatic venous drainage preservation) leading to left hemiliver (S2-4) regeneration. To optimize PVE results, recent effective techniques have been developed such as the simultaneous embolization of the right portal branch and the right hepatic vein (HV), and the right accessory HV if so, which is called liver venous deprivation technique. Additional simultaneous embolization of the middle HV defined the extended liver venous deprivation (ELVD) technique. ELVD induces right liver (S5-8) venous deprivation (deprivation of both portal input and venous drainage) and leads to rapid increase in FRL function. After ELVD, segment IV (S4) portal input from left portal branch is preserved while its venous drainage through the middle HV is disrupted, resulting in venous congestion. The aim of this study is to analyze the volumetric and functional evolutions after embolization procedures in deportalized liver (S5-8 after PVE), vein-deprived liver (S5-8 after ELVD) and congestive liver (S4 after ELVD).