15 June 2012
Team Led By Indian-Origin Researcher Raises Hopes For Bypass, Dialysis Patients
London: For the first time, scientists led by an Indian–origin researcher have successfully replaced a major blood vessel in a 10–year–old girl with a vein grown in a lab using her own stem cells.
The pioneering transplant, published in The Lancet, marks a further advance in growing body parts in laboratory and offers hopes for patients who lack suitable veins for dialysis or bypass surgery. In the landmark research, a team from the University of Gothenburg in Sweden took a vein from a dead man, stripped of its own cells and then bathed in stem cells from the girl, who was suffering from portal vein obstruction.
There was a "striking" improvement in her quality of life after the transplantation, professor Suchitra Sumitran–Holgersson, who led the research, said.
The hepatic portal vein drains the blood from the intestines and spleen to the liver. The blockage can cause serious complications like lethal variceal bleeding, enlarged spleen, developmental retardation, and even death. To date, attempts to restore portal blood flow using umbilical veins and artificial grafts to build a bridge around the blockage (called meso Rex bypass) have had mixed success.
The Swedish team took a 9cm segment of iliac (groin) vein from the dead donor and removed all living cells, leaving a tube consisting of just the protein scaffolding. This scaffolding was injected with stem cells obtained from the girl’s bone marrow. Two weeks after seeding, the graft was re-implanted during a meso Rex bypass procedure.
The girl had no complications from the operation and normal blood flow was immediately restored. In the year after the operation she gained good height and weight. But a year after the procedure, decreased portal blood flow was noted and a narrowing of the graft required a second stem cell-based graft to be done. Since, she has remained well and can walk long distances. She has not developed anti-donor antibodies despite not taking immunosuppressive drugs. PTI