Mechanisms of hepatic regeneration following portal vein embolization and partial hepatectomy: A review

Background: Portal vein embolization (PVE) improves outcome following major hepatectomy, and basic studies have presented evidence related to the mechanisms responsible for hepatic regeneration. Hemodynamic changes following PVE are similar to, but slightly different from, those of partial hepatectomy (PH) because arterial flow to the embolized lobe is preserved. However, the process of hepatic regeneration is essentially the same after both PVE and PH. A number of mediators are involved in PVE or PH-induced hepatic regeneration. These include inflammatory cytokines, vasoregulators, growth factors, eicosanoids, and various hormones. These mediators activate a complex network of signal transduction that promotes hepatic regeneration. A variety of conditions have been shown to modulate the function of these mediators and inhibit regeneration. These include biliary obstruction, diabetes, chronic ethanol consumption, malnutrition, gender, aging, and infection. Conclusion: Optimizing these factors, where possible, before PVE or PH, is essential to maximize hypertrophy of the liver. A fuller understanding of hepatic physiology and pathophysiology following PVE or PH may lead to greater functional capacity of the remaining liver and extend the indications for hepatectomy in patients who require large liver volume resection.