NEW YORK (Reuters Health) - In patients with large liver tumors requiring extensive hepatectomy, pulmonary vein embolization (PVE) plus infusion of bone marrow stem cells into the portal vein prior to resection accelerates and augments hepatic regeneration compared with PVE alone, according to a small study conducted in Germany.

Transhepatic percutaneous PVE has the potential to increase future liver remnant volume to some extent prior to resection, the researchers explain in the April issue of Radiology. Evidence suggests that hematopoietic stem cells participate in hepatic regeneration.

Against this backdrop, a team at Heinrich-Heine-University of Duesseldorf led by Drs. Gunter Furst and Jan Schulte am Esch prospectively compared the effect of PVE and CD133+ bone marrow stem cell administration to the liver segments to be retained, with PVE alone, in 13 patients with large central liver malignancies.

"They all were selected for PVE before scheduled extended right liver resection, because future liver remnant volume ranged below the margin that is required for sufficient liver function subsequent to surgery," co-investigator Dr. L. Benjamin Fritz noted in comments to Reuters Health.

Dr. Fritz and colleagues report that the relative gain in future liver remnant volume was significantly higher in the six patients in the PVE/stem cell group compared with the seven patients in the PVE-only group (77.3% vs 39.1%).

In addition, the mean daily hepatic growth rate was more than a twofold higher in the stem cell arm. "This resulted in a reduction in the time to surgery by an average of 18 days," the investigators report.

"By shortening the waiting time to a curative liver resection, the risk for these patients to experience a tumor advance beyond resectability prior to lifesaving surgery is minimized," Dr. Fritz noted.

"If these data can be confirmed in the upcoming randomized controlled trial, this novel therapeutic approach should be evaluated for other scenarios of liver damage and regeneration," Dr. Fritz said.