Liver Volume Restoration and Hepatic Microarchitecture in Small-for-Size Syndrome

We investigated preoperative parameters that could work as markers of liver regeneration (LR), and tried to create an algorithm for therapeutic decision-making, looking at the clinical setting of post-hepatectomy liver failure (PHLF) after major liver resection for malignancies (LRM) and of the small-for-size syndrome (SFSS) after adult-to-adult living related liver transplantation (LRLT), considering PHLF and SFSS a single clinical entity.

The clinical data of 2 series of 10 consecutive patients who experienced liver-specific complications after LRLT or LRM between 2008 and 2013 were analyzed. LR was evaluated by multidetector computed tomography (MDCT) and hepatic parenchymal findings with specific re-examinations of liver biopsies. The analysis was done according to demographics, tumor characteristics, and postoperative complications occurring within 90 days of surgery and codified within the Clavien classification.

A total of 13 cases of SFSS occurred in 8 LRLT recipients (61.5%) and in 5 patients after LRM (38.5%). The incidence of SFSS was significantly associated with a greater spleen volume/future remnant liver volume ratio (1.08±0.5; P=0.02) and a reduced number of hepatic tumors (0.58±0.6; P=0.04). A greater degree of LR was not associated with a lesser likelihood of developing SFSS (P=0.31). SFSS incidence and re-examination of post-operative liver biopsies differed according to the evidence of focal endothelial denudation in the portal vein and centrilobular hepatocanalicular cholestasis. We found an association between SFSS incidence and the immunohistochemical overexpression of cytological proliferation marker Ki-67 (29.3±29.8%; P=0.007), which was a significant predictor of poor post-operative survival (OR=1.12, C.I.: 1.013; 1.242).

SFSS is a rare but dangerous clinical entity characterized by anarchic hepatic regeneration. We suggest focusing on early diagnosis in order to establish non-surgical modulation of the portal inflow, in conjunction with optimization of medical management.