For the first time in the world, transplant surgeons at Toronto General Hospital, University Health Network used a new technique to repair an injured donor lung that was unsuitable for transplant, and then successfully transplanted it into a patient.
The use of this technique could significantly expand the lung donor organ pool and improve outcomes after transplantation.
In their ground-breaking research, a team of lung transplant surgeons led by Dr. Shaf Keshavjee in the Lung Transplant Program at Toronto General Hospital (TGH) developed an "ex vivo" or outside the body technique capable of continuously perfusing or pumping a bloodless solution containing oxygen, proteins and nutrients into injured donor lungs. This technique, the Toronto XVIVO Lung Perfusion System, allows the surgeons the opportunity to assess and treat injured donor lungs, while they are outside the body, to make them suitable for transplantation.
Unlike current cooling lung preservation techniques which inhibit cell metabolism and the possibility of any active repair processes prior to transplantation, the Toronto technique maintains donor lungs at a normal body temperature of 37 degrees Celsius, allowing for future organ repair and gene and cell therapy strategies to be used on them. Although lung perfusion systems have been used in Sweden and England, these systems were blood-based, short-term assessment strategies which were not capable of long-term maintenance or techniques to repair or recondition the lungs.
The Toronto System was used on donor lungs for Andy Dykstra, 56, who received his transplant on December 5, 2008. He had been waiting for a transplant since July 30, 2008, and was told of the clinical trial testing the new system on December 4, 2008. Recalling his difficulty breathing when walking to the front door in his home, Andy said that he waited only two seconds before deciding to be the first patient to receive the reconditioned lungs, which would not have been suitable for transplant without undergoing perfusion by the Toronto System. "When I was given this chance, the hair on my arms stood up, I was so excited. I knew it was right. I just had to go for it," he said, with his wife Chris standing by his side and nodding for emphasis.
Andy is part of an ongoing clinical trial which uses the novel Toronto strategy to identify donor lungs which do not meet current transplant criteria, repair them, and then transplant them into patients. To date, four patients in total have received lungs treated using this technique, and all have done well. But Andy was the first patient who received lungs which did not meet standard transplant criteria and which could not have been used if they had not been repaired first by the Toronto System. (The three others received donor lungs which met transplant criteria and which were further improved by the Toronto System.) All TGH patients waiting for a lung transplant are eligible to be part of this clinical trial, and the lung transplant team will assess all those who are interested.
"We are extremely pleased that Andy is doing so well," said Dr. Keshavjee who is Director of the Lung Transplant Program at TGH, Senior Scientist, The McEwen Centre for Regenerative Medicine, Director, Latner Thoracic Research Laboratories, and Professor and Chair, Division of Thoracic Surgery, University of Toronto, adding that Andy was able to breathe without any mechanical assistance just four days after the transplant and was discharged from hospital 12 days after the procedure. "This achievement was the result of years of research and pre-clinical planning by a large team of researchers, surgeons, physicians, nurses and other specialists. It means that many more donor lungs which we could not have used before can now potentially be used safely, and it sets the stage for more sophisticated molecular and cellular repair techniques to be applied in the Toronto XVIVO Perfusion System so that transplant outcomes can be further improved. The potential exists to immunologically pre-prepare the organ before it even sees the recipient's immune system."