Enhancing Hepatic Regeneration with Stem Cells and Portal Vein Embolization

Abstract

In patients scheduled for extended right hemihepatectomy, portal venous embolization (PVE) as an isolated modality may fail to induce an adequate hepatic volume response within a reasonable period of time. In particular, patients with very small future liver remnant volumes, compromised hepatic parenchyma or comorbidity, and impaired liver regeneration capacity may be initially considered unsuitable for resection. Hematopoietic and mesenchymal stem cells are promising candidates for cell-based approaches for the treatment of liver diseases. Possible stem cell interactions with the liver include stimulation of endogenous hepatocyte proliferation, transdifferentiation to hepatocytes, fusion of stem cells and hepatocytes, antifibrotic and immunomodulatory effects. In a new concept, autologous hematopoietic CD133+ stem cells are used to augment left lateral liver volume prior to extended liver resection. PVE was used as a strong proliferation stimulus to the nonembolized liver segments. Significantly increased hepatic growth rates and reduction of waiting time from PVE to resection surgery were found compared to a control group. No complications or side effects linked to the stem cell treatment were observed. Clinical follow-up revealed no significant differences in tumor-free survival times and recurrence rates. A randomized trial will be performed to validate the findings and to clarify if stem cells are a powerful adjunct to PVE in patients supposed to respond inadequately to PVE alone.