How is a kidney (renal) transplant performed?

Grafting a kidney from a compatible donor to restore kidney functions in a recipient suffering from kidney failure is called a kidney transplant. It is also known as a kidney transplant.
The first kidney transplant was performed between identical twins in 1954 by Dr. Charles Hufnagel, a Washington surgeon.

Eligibility: Anyone with end-stage kidney disease must undergo a kidney transplant to survive and live longer. However, people who are at risk for another life-threatening disease are not eligible for a kidney transplant.

Donors: Kidney from a living donor can be used for transplant. A donor can be an identical twin, sibling, or close relative. If living donors are not available, kidneys from cadavers can be used (a cadaver is a cadaver). In fact, more than half of kidney transplants worldwide come from cadavers. Various types of kidney transplants depending on the donors are:

A kidney transplant from an identical twin is called an isogenic graft or isograft. It is always successful.
A kidney transplant from a sibling, close relative, or cadaver is called an allogeneic graft or homograft. Allografts are usually successful with the use of an immunosuppressant.
Immunosuppressants are medications that prevent rejection of the graft by the body’s immune response and may need to be taken by the recipient for life. Many kidney transplant recipients have been found to have their kidney grafts functioning for more than 20 years.
Previously, kidney transplantation was limited or successful in patients under 55 years of age. However, with the development of better techniques today, kidney grafts have been performed in selected patients even as young as 70 years old.

The general steps in a kidney transplant procedure are:

1. Pre-transplant preparation: It includes the process of hemodialysis to ensure a relatively normal metabolic state and the provision of a functional and infection-free lower urinary tract.

2. Donor selection and kidney conservation:

A kidney donor must be free of hypertension, diabetes and malignant diseases.
Emotional stability, normal bilateral renal function, absence of other systemic diseases, and histocompatibility of a living donor are also carefully evaluated.
Cadaveric kidney is obtained from a previously healthy deceased person who suffered brain death but maintained stable cardiovascular and renal functions.
After brain death, the kidneys are removed as soon as possible, washed with special cooling solutions, such as mannitol, and stored in an ice-cold solution or may be cryopreserved.
These preserved kidneys must be transplanted within 48 hours to function well.

3. Match between recipient and donor: The recipient and donor are tested for three factors:

blood group: The recipient’s blood group must be compatible with the donor’s blood group.
Human leukocyte antigen (HLA): It is a genetic marker located on the surface of leukocytes. A person inherits a set of 3 antigens from the mother and 3 from the father. A higher number of matching antigens means they are more compatible and therefore increases the chances that the kidney grafts will work and last a long time.
Antibodies: Small blood samples from the recipient and the donor are mixed in a tube and if no reaction occurs, the patient can accept the kidney.

4. Transplant procedure:

The transplant is performed under general anesthesia.
The operation lasts around 3-4 hours. A cut is made in the lower abdomen.
The donor kidney is transplanted retroperitoneally into the iliac fossa.
The artery and vein of the new kidney are connected to the iliac artery and vein of the recipient.
The ureter of the new kidney is connected to the recipient’s urinary bladder.
Often the new kidney starts making urine as soon as blood flows through it, but sometimes it can take a few weeks before it starts working.
A stay of one week in the hospital is necessary to recover from the surgery and longer if there are complications.
The new kidney takes over the work of two defective kidneys. Unless they are causing an infection or high blood pressure, old kidneys are left in place without being removed.

5. Immunosuppression:

Immunosuppression means suppressing the recipient’s immune response to graft rejection.
Prophylactic immunosuppressive therapy is initiated just before or at the time of kidney transplantation.
An ideal immunosuppressant weakens the recipient’s immune system against any foreign tissue, but maintains immunity against infections and cancer.
The drug, called cyclosporine, is one of those immunosuppressants. The use of antiserum against human lymphocytes is equally useful. It destroys T cell-mediated immune responses but prevents humoral antibody responses.

References:

Nova Anatomy and Physiology
Atlas of human anatomy. seventh edition. Philadelphia, PA, Elsevier, 2019.