I am not totally sure about the procedure Cheney does follow. I have been a chemo nurse working in stem cell transplantations- autologous, which means patients with life threatening diseases like multiple myeloma and lymphoma, sometimes metastatic testicular cancer would go through this procedure. They would be admitted for 3-5 weeks, given chemo that would literally destroy their bone marrow, and then reinfused their own stem cells that would have been collected a month or 2 ago. The effects of the chemo were devastating on their bodies, putting them at risk of life threatening infections, and really raw GI tract, from mouth to rectum. These procedures would be used after all other treatment options would be exhausted because of the cost and risk involved.
With someone else's stem cells, even if it's placental, one has to worry about matching the donor cells to the recipient, since there is a risk of rejection.Any little variance and you have more chances to get "Graft vs host disease" which can leave you with liver, kidney, skin damage, amongst other things. It is definitly more risky and the mortality and morbidity risk is higher.
Please let me know if Cheney uses the same procedure. I am curious.