Kidney Transplantation: Thinking Outside the Box
Kidney transplantation has come a long way since the first successful transplant between identical twins in 1954. Since then, improvements in surgical technique, medical management, and immunosuppressive therapy have facilitated transplants from family members, genetically unrelated living donors, and deceased donors.
In 2005, over 16,400 kidney transplants were performed in the U.S., approximately 60% from deceased donors and the remainder from living donors.
Success rates have increased steadily, and now exceed 90% at one year and 50% at ten years.
Despite this extraordinary success, however, many challenges remain.
Topping the list is the chronic shortage of organs, which creates dilemmas about fairly allocating kidneys to patients with varying degrees of need, risk, and potential benefit.
Another major challenge is medical in nature finding safe and effective ways of overcoming the bodyís natural tendency to reject the new kidney.
At NewYork-Presbyterian Hospital/Columbia University Medical Center, the Renal and Pancreatic Transplantation Program is leading the nation in addressing both of these critical areas.
"Our goal is to successfully transplant as many patients as possible so they can return to normal, productive lives," says Lloyd E. Ratner, MD, Director.
"We are not content to accept the status quo."
Meeting the challenge of organ shortage
To meet the high demand for donor organs in the New York metropolitan area, the program has developed new ways to safely use more organs than ever for transplantation.
First, it has implemented new protocols for using extended criteria organs that may not meet the usual criteria for transplantation, but are healthy enough for a successful transplant.
Donor kidneys that might go unused in regions with fewer people on the organ waiting list can be matched with appropriate candidates in areas with greater demand, according to Dr. Ratner.
Organs in this category include those from donors who are older, have hypertension or diabetes, or who at the time of their death suffered mild kidney injury.
As is the case with heart, liver, and lung transplantation, the use of extended criteria kidneys is proving highly successful, especially among older recipients and those doing poorly on hemodialysis.
Second, the program has developed strategies to address immunologic issues that, until recently, were thought to preclude transplantation.
Using new methods to "clean" mismatched antibodies from the recipientís blood, the program now performs incompatible donor transplantation of kidneys into recipients whose immunologic makeup would normally result in rapid rejection of the new organ.
The long-term survival rate for incompatible transplants is exactly the same as for compatible transplants at NewYork-Presbyterian/Columbia, one of of the few institutions in the world offering this option today.
To further maximize transplant opportunities, the program has instituted an aggressive approach to its waiting list.
Its Top 40 List identifies the ten patients from each of the four blood groups who are most likely to receive a kidney transplant in the near future.
These patients are specially evaluated so that any medical or psychosocial problems, or new financial or insurance issues that would affect transplantation, can be addressed.
Patients unfit for transplantation are placed on the inactive list while these issues are resolved.
This process is repeated every two to four weeks, ensuring that all patients on the list are "optimized" healthy, ready, and available to undergo transplant when a kidney becomes available.
A study by nurse coordinator Johanna Camacho-Rivera, RN, which won the Quality Assurance/Improvement prize at the UNOS Transplant Management Forum in April 2006, found that during the strategyís first year, waiting time for transplantation at Columbia was better than halved, from about six to two or three years.
Dr. Ratner has pioneered still other creative strategies to make use of a potentially viable donor organ.
He is the first physician to perform dual renal transplantation, the transplant of two adult kidneys into a single recipient.
"If one suboptimal kidney would not provide sufficient function, two may give excellent renal function," says Dr. Ratner.
In another first, Dr. Ratner performed the first paired kidney exchange ("swap") in New York City in 2004. Kidney swaps entail trading the healthy and willing, but incompatible, donors of two patients, enabling both patients to receive compatible kidneys.
A unique procedure, kidney swapping requires four simultaneous operations (the two donations and two transplants).
Moving from a double to a triple swap, the team performed the regionís first three-way kidney exchange, which required six concurrent operations, on May 30, 2006.
Three-way kidney transplant allows three patients with no compatible donor to receive life saving kidneys. Pictured: one of six operating rooms used for a 3-way transplant conducted at NewYork-Presbyterian Hospital/Columbia on May 30, 2006.
"The beauty of this approach is that by simply working out the logistics, we can give people straightforward transplants, with excellent results," explains Dr. Ratner.
"There is an urgent need for donors," according to Joan Kelly, RN, Renal Transplant Coordinator.
"We hear from 50 people every month who need transplants.
Often family members would be willing to donate, but donít realize they can be donors."
To provide the best care possible for those considering donating a kidney, the program has established an extremely thorough and exemplary system of living donor evaluation and advocacy.
Preventing rejection after transplant
Investigators in the Departments of Surgery and Medicine are now testing new immunosuppressant drugs with fewer uncomfortable side effects.
"It is critical to develop new and better ways to prevent rejection," says Mark A. Hardy, MD, Director Emeritus and founder of the Renal and Islet Transplantation program.
Dr. Hardy is Principal Investigator of a multicenter clinical trial exploring a combination of two immunosuppressant drugs, sirolimus and tacrolimus.
"Both of these drugs prevent the activation of T-cells," says Dr. Hardy.
He and colleague David J. Cohen, MD, Medical Director of Renal Transplantation, hope this combined medical therapy will reduce rejection episodes and lead to improved kidney function in the long term.
In another study, they are evaluating new classes of immunosuppressive medications which hold great promise in avoiding many of the side effects of currently used drugs.
They are also investigating methods of induction therapy, which promotes tolerance to the foreign kidney, including Campath 1-H, thymoglobulin and monoclonal antibodies for Il2R, and HLA allopeptides.