The Karolinska Institute in Stockholm has decided that surgeon Paolo Macchiarini is not guilty of scientific misconduct in his treatment of three patients with tissue-engineered tracheas. The decision, announced this morning by Vice-Chancellor Anders Hamsten, disagrees with the conclusion of a report by an independent investigator, released in May, which did find that Macchiarini had committed misconduct.
Macchiarini, a visiting professor at the Karolinska, led teams that transplanted artificial tracheas into three patients at the Institute’s hospitals. The patients had suffered damage to their tracheas due to cancer or side effects from another surgery.
The tracheas were made of a polymer scaffold which was seeded with the patients' own stem cells. The stem cells were supposed to grow into and over the scaffold to create a functional trachea. The first patient survived for 2 years after the operation. The second patient died a few months after receiving his transplant; the cause of his death was never made public. The third patient has been in intensive care at Karolinska since receiving her transplant in August 2012.