Professor Anders Hamsten announced his resignation in an article in Sweden's Dagens Nyheter on Saturday, arguing that staying would hurt the institute's “credibility”.
“The chorus of voices raised to demand my resignation is so multifarious and strident that I realise it will be difficult for me to continue working as Vice Chancellor of Sweden's most successful university,” he wrote.
Hamsten controversially exonerated Italian surgeon Paolo Macchiarini from charges of scientific misconduct last summer, despite a growing storm over his ground-breaking synthetic trachea transplants.
“Today I can see that I completely misjudged Paolo Macchiarini and that he and KI should have gone their separate ways far earlier,” Hamsten wrote. “KI failed to see the warning signs early enough and did not pay enough attention to the warnings that came from doctors working close to Paolo Macchiarini.”
He said that he now believed that Macchiarini had committed “scientific misconduct, which in plain language means research fraud.”
The resignation came as the institute announced that it would re-open the fraud investigation Hamsten oversaw last year.
The ”Macchiarini affair” burst back into life last month, when a documentary, The Experiment, was broadcast on Sweden's public television channel SVT, which suggested that Macchiarini hadn't fully informed his patients about the risks of his pioneering trachea implants.
Most of the patients died, including at least one-a woman treated in Krasnodar, Russia-who was not seriously ill before the surgery.
”We have now analysed the images shown in the documentary by Swedish Television and this brings us a whole new picture of the process after the surgery on the patient,” Jan Carlstedt-Duke, professor and adviser to the vice-chancellor at Karolinska Institutet, said. “This strengthens the suspicions of scientific misconduct by Paolo Macchiarini.”
Carlstedt-Duke said that the institute had also recently received a report alleging scientific misconduct in two of Macchiarini's articles on transplants in rats.
“When looking at images in those articles several of them seem to be very similar. That leads us to clearly suspect that data published in those publications is incorrect,” he said. “We will now investigate this thoroughly and get an independent review of this data.”
Lars Leijonborg, chairman of the institute's board, thanked Hamsten for his three years in the position.
“The recent period has been difficult for both KI and him. I have the deepest respect for his decision to resign,” he said.
He reiterated the institute's plan to launch an external investigation into its handling of the case led by Sten Heckscher, a prominent Swedish lawyer and Social Democrat politician.