The circumstances in which a baby girl died some months after undergoing what was hoped would be life-saving surgery to fix a heart defect were described at an inquest in Co Donegal yesterday.
The inquest found that medical misadventure was the cause of death of six-month-old Molly Markey.
Her mother, Maria Markey, said she was pleased "the evidence shows Molly's valve was contaminated, which tragically led to her death".
The Coroner's Court in Carndonagh, Co Donegal heard how Molly, who was born on May 10th, 2005, in Derry's Altnegalvin Hospital, had a rare heart disease - Type I truncas arteriosis - which affects one in every 10,000 babies born in the Republic.
On July 6th, 2005, the baby underwent surgery at the Royal Belfast Hospital, where she was referred, to have a heart valve, made by American company Shelhigh, inserted.
A postmortem examination was carried out by consultant histopathologist Dr Michael McDermott, who found that Molly died from a large ventricular aneurysm - a ballooning of a blood vessel in the ventricle - which was blocked with a blood clot.
The court also heard how he discovered she had an infection in the valve.
The parents' lawyer, Raymond Bradley, asked Dr McDermott if the infection was present as a result of an unsterile valve. He replied: "I would think that is the most likely explanation." He said no other sites in Molly's body were found carrying the infection.
After Molly's death, the Irish Medical Board (IMB) launched an inquiry into use of the Shelhigh product, which has seen more than 26,000 units distributed in the EU since 1999. It has not been used in the Republic since 2001. Anne O'Connor, the board's medical devices director, told coroner Dr John Madden an inquiry was conducted by the Spanish medical authorities into its safety licence.
A working group was set up to look into the case. She said they examined the product batch and were satisfied it was sterile.
Mr Bradley then revealed the IMB had investigated the wrong batch.
Mr Bradley told the court Shelhigh had been under investigation in the US by the Food and Drug Administration since 2000 for issues centred on quality control and sterility. Shelhigh products had since been seized by the Food and Drug Administration.
Mr Bradley criticised the IMB for solely relying on the Spanish authorities and not liaising with the US investigation.
Because Molly was born in Derry and had her treatment in Belfast, which Mr Bradley said was simply due to the "geography", no evidence was given by the cardiologist because Molly died in a different jurisdiction.
Ms Markey, along with Molly's father Paul Gregan, said: "I think it speaks volumes that the jury said they were happy that the Shelhigh valve was not to be used in the Republic. It's use in Northern Ireland should seriously be re-examined."
Dr Madden said: "To lose a family member is a very hard thing for any family to put up with but to lose a child sadly is doubly hard and unnatural. But to lose a child who has fought so well and bravely through surgery and who you thought was on the up and up - well, to lose her then it is a terrible tragedy and triply hard."
The jury spokesperson said they were pleased the Shelhigh valve was not used in the Republic and urged the authorities in the North to look into it.