It works like this, Minnee explains: “When a liver has just been transplanted, it excretes many waste products that are not good for the kidneys. If the brand-new donor kidney has to process these waste products right after being transplanted, it will have a slower and more difficult start. This means that the patient will often require dialysis for the first few days”. If you wait for about 24 hours before transplanting the donor kidney, then the body has a chance to process these waste products on its own.
There is another reason to wait before transplanting the kidney. “Just after surgery, the kidney requires slightly higher blood pressure and extra fluids for effective urination. The liver, on the other hand, prefers not to have this high blood pressure and functions better with an equal fluid balance.
Furthermore, the liver makes clotting factors, but it cannot do this optimally right after the transplant. By introducing a break, you are doing both donor organs a favor.”
Annually, there are about six patients who qualify for this combined liver-kidney transplant, for example due to a metabolic disease. This is a condition, often caused by a genetic error, in which proteins or other substances accumulate in the organs. This will eventually lead to liver and kidney failure.
Initially, patients can compensate for poor kidney function by undergoing dialysis. However, once the liver has deteriorated so badly that a liver transplant is necessary to save the patient’s life, a donor kidney often has to be transplanted at the same time.
The new method was first performed and investigated in the United States. “A total of 130 patients were divided into two groups”, says Minnee. “One group had a liver and kidney transplant in a single operation, while in the second group the new kidney was connected to a perfusion pump for an average of two days before transplantation. The patients in the second group were found to recover faster and better.” But having to undergo surgery twice in such quick succession… isn’t that tough for patients? “The benefits of a break between the transplants far outweigh the disadvantages.”
Erasmus MC Transplant Institute has now performed two of these ‘delayed double transplants’. Ideally, Minnee would always prefer to perform these double transplants using the new method. “The tendency of transplant surgeons has always been to transplant an organ into the recipient as soon as possible after removal”, he explains.
However, a perfusion pump, in which a donor organ is first flushed with a perfusion fluid for a while, gives good results. The introduction of this perfusion technique made it possible to test such a delayed method. And, as has now been shown, with good results. Those results are still improving: “Current observations show that a kidney can be preserved outside the human body for no more than 48 hours when connected to the pump. But there are now indications that the results are even better if the kidney is flushed for more than 48 hours. We are getting better and better at what we do.”