03 Mar 2010
When 54-year-old Madam Susan Ong received a call on 21 Dec 2009 to come to the Hospital, she was not aware that she would become Singapore’s first dual-kidney transplant using kidneys from a deceased donor over the age of 60.
Madam Ong has been on dialysis since 2001 when she developed end-stage kidney failure from an advanced kidney disorder. She was on the waiting list for a kidney when she agreed to receive a dual kidney transplant from a 62-year-old donor. Tissue from the kidney of the older donor was sampled to determine whether there was enough functional kidney tissue for the kidneys to be placed together into one recipient or separately into two recipients. Test results showed that it was best to place two kidneys into one patient. Madam Ong then became the first recipient of both the kidneys from the same deceased donor.
Dual-kidney Transplantation from an Older Donor
A major impediment to kidney transplantation in Singapore is the current shortage of donor kidneys. Currently 460 patients with end-stage kidney failure are awaiting kidney transplantation while the number of deceased donors remain stable at approximately 25 each year in Singapore.
In a bid to further increase the number of organs available for transplant, the Ministry of Health (MOH) had lifted the upper age limit of 60 years for deceased organ donation under the Human Organ Transplant Act (HOTA) from 1 Nov 2009. It has been estimated that this would provide up to 10 to 12 additional organ donors per year, which could potentially benefit 70 more patients each year.
Dual-kidney transplantation is the procedure where a pair of kidneys with reduced functional mass are transplanted into a single patient. The rationale is that if two kidneys with reduced functional mass are given to the same recipient, this may result in as much or more functional mass as in a single kidney with optimal functional mass. The use of such kidneys may help increase transplant rates and reduce the long waiting list in Singapore.
The first dual kidney transplants from older donors were performed in the United States in 1994. Since then, transplant centres from the United States, Europe and India have performed dual kidney transplants from older donors. Their experience suggest that outcomes are just as good as a single kidney with optimal function and may help address the shortage of donor organs.
To ensure best transplant outcomes, donated organs are evaluated according to strict medical criteria, and allocation of organs from older deceased donors will depend on clinical considerations such as tissue compatibility, functional reserves, exclusion of infections or cancers and the medical fitness of the potential recipients.
"If you select the donor and recipient well, the outcomes of dual-kidney transplantation from older donors are better than if single kidneys of older donors were used. Furthermore, outcomes of dual kidney transplantation appear comparable to those using single kidneys from younger donors,” said Dr Terrence Kee, Consultant, Department of Renal Medicine, SGH.
“The challenges of a dual kidney transplant is getting the right donor, the right recipient, choosing the right side(s) to put the kidneys and using the right drugs to ensure the kidneys will function optimally,” said Dr Tan Yeh Hong, Senior Consultant, Department of Urology, SGH.
In the case of Madam Ong, doctors decided to choose a smaller size recipient whose metabolic demands will be met by the dual kidney transplant and who was judged to be at low immunological risk for rejection. Immunosuppression drugs also had to be balanced between the risks of toxicity to older kidneys versus the need to be effective enough to prevent rejection. In this case, doctors had deliberately reduced the doses of Immunosuppression drugs by half to minimize toxicity to the older kidneys.
The dual kidney transplant also presented SGH’s surgeons with some technical challenges due to the demanding and complex nature of the surgery. Lasting one to two hours longer than a single kidney transplant surgery, two senior surgeons were needed to implant the two kidneys in the recipient. There were also technical issues related to placing two kidneys on one side. An emergency CT-angiogram of the patient’s vascular supply to the leg had to be done before the surgery to ensure that implanting two kidneys on one side will not run the risk of taking blood flow away from the leg. Furthermore, surgeons also needed to work fast as older kidneys do not tolerate long storage time before surgery.
Click for pdf format
« Back to previous
page