Longer Time on Dialysis Post-Tx Associated with Worse Outcomes
LAKE LOUISE, Alberta—Patients who need a prolonged period of dialysis after receiving a kidney transplant have more post-transplant complications and lower estimated glomerular filtration rate at one year (eGFR) compared with patients who do not, a study has confirmed.
Although the majority of transplanted kidneys function right away, approximately 20%-30% of the time the kidney experiences delayed graft function (DGF) and in these cases, dialysis is needed to support the patient until the kidney begins to function. An analysis of 83 transplant patients presented at the 2013 annual meeting of the Canadian Society of Transplantation showed that those patients that needed dialysis for longer periods had a higher risk of complications and had a reduced eGFR one year after transplantation.
“It's surprising that time needed on dialysis has not been explored much in the past,” lead investigator Michael Moser, MD, told Renal & Urology News. “Anecdotally, we always thought that the kidney that took three weeks to ‘wake up' must be worse off in some way than the kidney that woke up after one week, but we wanted to formally confirm this.”
Dr. Moser, a member of the Saskatchewan Renal Transplant Program the St. Paul's Hospital in Saskatoon, Saskatchewan, and his colleagues collaborated with Patrick Luke, MD, and others in the Multi-organ Transplant Program at the London Health Sciences Centre in London, Ont. They reviewed data from 567 kidney transplants in London and 227 in Saskatoon performed between January 2004 and December 2011.
Eighty-three of the patients had delayed graft function, including 52 who were on dialysis for up to one week after transplantation, 13 who were on dialysis for between one and two weeks, and 18 who required more than two weeks of dialysis after the kidney transplant. The three groups had similar ratios of males to females, ages, donor age, type of dialysis, proportion of machine cold pulsatile perfusion, and length of cold ischemia time.
The length of time on dialysis after transplantation, number of dialysis sessions, and length of hospital stay were all significantly greater in the patients on dialysis for more than two weeks. Their eGFRs at 30 days and at one year were also significantly lower—20 and 37.3 mL/min/1.73 m2, respectively—than those from patients with shorter post-transplant dialysis times.
In addition, 44% of people who were dialyzed for more than two weeks post-transplant were still on dialysis at 30 days post-transplant compared with none of the patients who had shorter time needed on dialysis. Furthermore, 72% of patients on dialysis for at least two weeks post-transplant had at least one complication compared with 25% of those on dialysis for fewer than seven days and 54% of patients on dialysis for 7-14 days.
The investigators also found that kidneys from donors after cardiac death (DCD) who had DGF actually had markedly better eGFR's at one year compared to non-DCD kidneys experiencing DGF. This interesting finding suggests that there may be a different mechanism for DGF in the two types of donor kidney transplants.
“Our study differed from previous studies in that it included patients receiving kidneys from DCD donors and more expanded criteria donors than the early studies,” the team noted in a poster presentation. “A follow-up study has been done which looks further at the effect of DCD kidneys and length of time needed on dialysis.”