Kidney Transplantation or Renal Transplantation

Kidney transplantation or renal transplantation is the organ transplant of a kidney into a patient with end-stage renal disease. Kidney transplantation is typically classified as deceased-donor (formerly known as cadaveric) or living-donor transplantation depending on the source of the donor organ. Living-donor renal transplants are further characterized as genetically related (living-related) or non-related (living-unrelated) transplants, depending on whether a biological relationship exists between the donor and recipient.

Indications

The indication for kidney transplantation is end-stage renal disease (ESRD), regardless of the primary cause. This is defined as a glomerular filtration rate < 15ml/min/1.73 sq.m. Common diseases leading to ESRD include malignant hypertension, infections, diabetes mellitus, and focal segmental glomerulosclerosis; genetic causes include polycystic kidney disease, a number of inborn errors of metabolism, and autoimmune conditions such as lupus. Diabetes is the most common cause of kidney transplantation, accounting for approximately 25% of those in the US. The majority of renal transplant recipients are on dialysis (peritoneal dialysis or hemofiltration) at the time of transplantation. However, individuals with chronic renal failure who have a living donor available may undergo pre-emptive transplantation before dialysis is needed.

Procedure

In most cases the barely functioning existing kidneys are not removed, as this has been shown to increase the rates of surgical morbidities. Therefore, the kidney is usually placed in a location different from the original kidney, often in the iliac fossa, so it is often necessary to use a different blood supply:

There is disagreement in surgical textbooks regarding which side of the recipient's pelvis to use in receiving the transplant. Campbell's Urology (2002) recommends placing the donor kidney in the recipient's contralateral side (i.e. a left sided kidney would be transplanted in the recipient's right side) to ensure the renal pelvis and ureter are anterior in the event that future surgeries are required. In an instance where there is doubt over whether there is enough space in the recipient's pelvis for the donor's kidney the textbook recommends using the right side because the right side has a wider choice of arteries and veins for reconstruction. Smith's Urology (2004) states that either side of the recipient's pelvis is acceptable, however the right vessels are "more horizontal" with respect to each other and therefore easier to use in the anastomoses. It is unclear what is meant by the words "more horizontal". Glen's Urological Surgery (2004) recommends putting the kidney in the contralateral side in all circumstances. No reason is explicitly put forth; however, one can assume the rationale is similar to that of Campbell's—to ensure that the renal pelvis and ureter are most anterior in the event that future surgical correction becomes necessary.