Kidney transplantation in adults: Timing of transplantation and issues related to dialysis

 Kidney transplantation in adults: Timing of transplantation and issues related to dialysis

Mortality : Kidney transplant better than Dialysis

Preemptive Transplant is better than post dialysis transplant : graft (n = 40000) and patient survival (n = 7948)

Preemptive transplant is not suitable for 2 patients:

1) severe nephrotic syndrome: due to high risk of thrombosis perioperatively especially vascular thrombus of transplant. this patient either you dialyse first until the kidney fails and stop producing proteinuria or if you really keen on preemptive dialysis, you need to stop or plan to stop the nephrotic syndrome e.g. nephrectomy during kidney transplant, renal artery embolization or medical nephrectomy. 

2) Patient who is within 1 year of failed transplant. Such patient may benefit from a short period of dialysis prior to a second transplant. 

The longer a patient of dialysis prior to transplant , the higher risk of mortality. 

Better graft survival is due to less delayed graft function and less acute rejection. Dialysis also causes accumulation of solutes that usually cleared by kidneys -> increasing risk of atherosclerosis, malnutrition and chronic inflammation. 

>65 years who are on dialysis for 4-5 years, no survival advantage seen with living or deceased donor transplantation compared with dialysis

higher risk of cancer the longer on dialysis prior to transplant. 

No real difference between pre transplant HD and pre transplant PD. studies that supported PD were of low or very low quality evidences.

Dialysis within 24 hours prior to transplant increases the risk of delayed graft function esp if UF. another study of n = 110 found no difference. Therefore we should avoid UF 16-24 hours prior to transplant. 

Although not studied in the transplant perioperative period, a retrospective study n = 80 showed patients on chronic HD : 1.7 x higher risk of sudden death if operated within 12 hours after dialysis.  -> now I know why anaesthetist is not happy to anaesthetize if same day dialysis. 

If to perform UF prior to transplant, give enough time prior to transplantation to allow fluid to redistribute to intravascular space. only reserve for fluid overload patient. if euvolaemia, to avoid UF as risk of hypovolaemia and therefore delayed graft function due to pre renal reason. 

Complement-activating or bioincompatible membrane dialyzers (eg. cuprophane dialyzers have been associated with delayed graft function. 

20% patients require dialysis post transplant

Definition of Delayed graft function = requires dialysis post transplant regardless of the cause

Delayed graft function has been independently associated with nearly two- to threefold increases in patient death, graft failure, and death-censored graft failure

US nephrologists (uptodate team) perform HD post transplantation. they dont like PD as they worry about peritoneal membrane breach and leakage of high dextrose PD fluid. 

If the allograft demonstrates satisfactory perfusion and diuresis intraoperatively, transplant surgeons usually will remove the PD catheter during the operation. For marginal allograft appearance and/or delayed diuresis, the PD catheter remains in place in case PD is necessary postop.

Patients at high risk for peritonitis may benefit from earlier catheter removal. one retrospective study of 232 patients on PD found that a significantly increased incidence of peritonitis occurred in those with the following clinical characteristics

●An increased number of peritonitis episodes prior to surgery (median of three)

●Previous peritonitis episodes due to Staphylococcus aureus

●Male sex

●Technical problems at surgery

●More than two rejection episodes

●Permanent graft nonfunction

●Urinary leak