ABOVE: Paolo Macchiarini giving a lecture in Sweden in 2011 Stefan Zimmerman/TT, Alamy

Paolo Macchiarini, a once-lauded trachea surgeon, has been convicted in Sweden of causing felony bodily injury to one patient through negligence, but was acquitted on charges of assault related to additional surgeries on two other patients; all three died in the months and years following their procedure. The judges in the case handed down a conditional sentence of two years of probation, meaning that Macchiarini’s sentence will be reexamined if he commits another crime within that period, The Local reports. 

Elaborating on the sentencing decision, one of the judges, Björn Skånsberg, tells the Swedish news outlet SVT Nyheter that “we have in itself come to the conclusion that all three patients have suffered serious bodily injury and suffering. But we believe that no investigation has been presented that shows that Paolo Macchiarini intended to cause the effects or that he was indifferent to the patients being inflicted with these injuries,” according to a Google Translate translation.

Macchiarini was once a star surgeon in Sweden, hired by the Karolinska Institute (KI) and the Karolinska University Hospital to bolster the country’s standing in regenerative medicine innovation. His specialty was developing artificial tracheas—the first in the world—that were formed in part from a person’s own stem cells. Between 2011 and 2014, Macchiarini is known to have performed three such transplants in Sweden and five in Russia, according to Barron’s, and another—in a young girl—was carried out in the US in 2013. 

This latter case was one of three considered by the current sentencing decision. Hannah Warren, a toddler who had been born without a windpipe, was the youngest person ever to receive a bioengineered organ but died three months after her surgery. The other two patients also died following complications: The Local reports that the 2014 autopsy of one man revealed that his artificial trachea had almost entirely dislodged and become infected, while in another case, a woman underwent more than 200 corrective surgeries between her initial procedure in 2013 and her death in 2017. In total, BBC News reports that at least seven people had died following synthetic tracheal surgeries as of 2016.

In their ruling, Skånsberg and the second judge in the case, Ewa Lindbäck, said that while there was no evidence suggesting Macchiarini had acted with intentional malice, the deaths of the first two patients should have been enough to give him pause about operating on the third. This, they note in a statement translated from Swedish using Google Translate, is why he was ultimately convicted on the single count of bodily injury. “The benefit that the treatment method could be expected to bring was simply not in proportion to the risks that the procedure was associated with,” the judges write.

Even before some of the surgeries took place, concerns had arisen that perhaps Macchiarini was not acting in an ethical manner. As early as 2011, he was accused by another academic, Pierre Delaere of UZ Leuven in Belgium, of misrepresenting research findings in papers that went on to be published in prestigious journals. In 2012, Macchiarini was arrested in Italy and charged with fraud and attempted extortion. 

Several subsequent investigations by independent panels, KI, and the Swedish Research Council, among others, revealed that Macchiarini had falsified his resume, published papers based on fake or misleading data that were later retracted, and operated without proper ethical oversight, including failing to seek ethical approval for surgeries and to retrieve consent forms from patients. In 2013, the Karolinska University Hospital suspended further surgeries and refused to renew Macchiarini’s contract, Barron’s reports. After initially clearing Macchiarini of misconduct, KI fired him in 2016, after an independent investigation commissioned by the institute found that the surgeon had “engaged in conduct and research that is incompatible with a position of employment at KI.”

The Associated Press reports that in 2018, Sweden decided to reopen an investigation into the three deaths. During the investigation, officials gathered more written evidence and interviewed individuals in Sweden, Belgium, Britain, the US, and Spain. The results of the investigation led to the criminal charges of assault and negligence.

Matthias Corbascio, a cardiac surgeon at KI who testified in the trial, tells SVT Nyheter that he doesn’t believe justice has been done. “My reaction is that it is very meager. It is a terrible scandal and terrible for the patients’ families that he could get away so easily,” he says.

The saga has led to a series of resignations from people at the Karolinska Institute involved in Macchiarini’s hiring and in a guilty verdict for six of Macchiarini’s collaborators who worked with him on papers that were subsequently retracted. In 2019, Sweden also passed a law creating a board for investigating claims of research misconduct in the country. Speaking to Nature when the law first passed, Margaretha Fahlgren, a professor at Uppsala University in Sweden who led one of the inquiries into Macchiarini, said that “the research community has been very highly trusted by the public, but we had this big scandal. It changed the public image of research and researchers.”