Kidney Transplant | All You Need To Know About Kidney Transplant

Humans have got a pair of bean-shaped kidneys located on both sides of their spinal column. The kidneys play various important roles in keeping the body healthy including:

1. Filtration of the blood to eliminate metabolic wastes from regular bodily activities, excretion of waste as urine, and return of water and chemicals to the body as needed.
2. Blood pressure is controlled by the release of many enzymes such as renin.
3. The hormone erythropoietin is released from the interstitial cells of the kidneys to stimulate the synthesis of red blood cells.

Although kidneys are vital organs, humans can live almost normally with only one kidney. Kidney transplantation is a surgical procedure that involves removing a kidney from one person and implanting it into another one who is suffering from end-stage kidney disease. When compared to dialysis, kidney transplantation is the best therapeutic option for people with end-stage renal illness because it provides better long-term survival and quality of life.

Rates and Numbers

The number of the performed kidney transplants varies significantly among countries. A study conducted in 2019-2020 showed that Spain had the highest rate of kidney transplant procedures at 57.7 per million population followed by Denmark. Whereas Bulgaria showed a very low incidence of kidney transplantation (1.2 per million). Documentation centers in the US showed that more than 515,000 kidney transplants have been performed in the United States since 1988. In 2019, a net of 24,502 kidney transplants were done in the United States, including 6915 from living donors and 17,586 from deceased donors. In 2019, 244,000 people had a functional transplanted kidney.

The current form of kidney transplantation has resulted from a series of modifications and research which eventually lead to a higher success rate. Over the last three decades, the success rate of the performed kidney transplantation has increased significantly. At the moment, it is estimated that the survival rate of patients a year after getting kidney transplantation is 95% and up to 90% after three to five years. Although the lifespan of the patient who underwent kidney transplantation is a bit below average, it is much better than dialysis.

Life expectancy is one of the most frequently asked questions by patients who consider kidney transplantation. First of all, the expected life span of kidney recipients is variable and differs from one patient to another according to his general health condition, kidney matching, and time of transplantation. Statistically, the life expectancy for a recipient of a deceased-donor kidney is 8 – 12 years while the recipient of a living donor kidney is 12 – 20 years.

Costs & Facilitations

Costs of kidney transplantation vary considerably in a wide range. Health facilities in the US are believed to cost kidney transplantation much more than in other countries, therefore many US citizens travel abroad to get quality treatment for lower prices. In 2020, the average cost of kidney transplants in US hospitals was estimated to be 442,000 US dollars. India is well-known for its high-quality medical services with affordable prices as the costs of kidney transplantation may start from 15,000 US dollars. Not only hospitals in India but also in Turkey, Germany, and Egypt provide kidney transplantation with superior quality for lower prices.

Unfortunately, the costs of kidney transplants are expensive and unaffordable for many patients. Usually, patients with health insurance are financially supported to get transplantation. Health insurance companies have different policies and insurance plans. Most standard health insurance plans cover partially the expenses of a kidney transplant. Medicare coverage is around 80% of the costs of the pre-operative evaluation, transplant procedure, follow-up treatment, and immune-suppressive medications. Private insurance companies cover variable percent of the total fees.

Organ Donation

The donated kidney used in transplantation could be provided by a deceased organ donor or a living donor. A living donor is a healthy person who wishes to donate one of his kidneys. The living donor should be in perfect health and disease-free. The donor should also be aware of the transplantation and give written consent to the donation.

The living donor is usually siblings, relatives, and close friends. A deceased donor is a person who has just passed away but has functioning kidneys. A consent to donation is usually given by family members at the time of death, so the patient’s organs could be removed and preserved.

Indications & Candidates of Surgery

Who is a candidate for a kidney transplant? Kidneys are valuable organs, therefore nephrologists will not recommend kidney transplantation unless the patient is suffering from ESRD. End-Stage Renal Disease (ESRD) is a non-specific medical condition in which the patient’s kidneys are no longer functioning which necessitates long-term dialysis. We will summarize the most common indication for kidney transplantation.

Diabetes is believed to be the most common cause of end-stage renal disease. Diabetic nephropathy which is also known as diabetic kidney disease is a chronic deterioration of kidney function that occurs in patients with uncontrolled diabetes. Diabetic nephropathy is one of the leading causes of chronic kidney disease (CKD). Patients with diabetic nephropathy usually complain of increased frequency of urination, puffy eyelids, and swelling of the feet.
Hypertension, particularly uncontrolled hypertension, is estimated to contribute to 21% of the total end-stage renal diseases. Hypertensive nephropathy is a medical condition that involves kidney injury which is attributed to unmanaged hypertension.
Glomerulonephritis is an inflammation of the glomeruli which is the network of blood capillaries at the beginning of the nephron (the functional unit of kidneys). Glomerulonephritis could be caused by different agents such as viral infection, autoimmune disease, and exposure to toxins. Mostly, patients with glomerulonephritis respond well to treatment, yet resistant cases may necessitate kidney transplantation.
Cystic kidney diseases (CKD) are a group of diseases that form cysts (sacs filled with fluids) in or around the renal tissue. CKDs include polycystic kidney disease, medullary cystic disease, and medullary sponge kidney. Cystic kidney disease could be asymptomatic showing no manifestations for a long period until it interferes with kidneys function. Cysts not only reduce blood filtration of wastes and accumulation of toxins in the body but also get bigger and stretch the renal capsule causing flank dull-aching pain. CKD is believed to represent about 8% of the causes of a kidney transplant.
Pyelonephritis is an upper urinary tract infection that affects the kidney. Inflammatory reactions resulting from infection may damage renal tissue and cause acute kidney injury. In the case of unmanaged pyelonephritis, severe and irreversible destruction occurs to the kidney which may indicate a kidney transplant.
Congenital anomalies of the kidney are a common indication for kidney transplantation in pediatric medicine. Annual documentation of kidney transplants in the US showed that 37% of kidney transplants performed for pediatric patients are due to congenital anomalies.
Glomerulosclerosis is a medical disorder in which the fine blood capillaries of the kidneys are partially fibrosed. Although FDA hasn’t approved yet a cure for glomerulosclerosis, kidney transplantation is an available option.

Pre-operative Evaluation

Patients eligible for kidney transplantation should perform a group of special serological tests. These special blood tests are prerequisites for operation and are required to determine the type of blood and tissue. Test findings contribute to matching a donor kidney to a recipient’s kidney. These tests include:

1) Blood Typing Test

Blood typing test is a well-known procedure to find out which blood group the patient has. There are four blood groups: A, B, AB, and O. Everyone falls into one of these types. The donor, as well as the recipient, should have the same blood type or compatible blood types.

Patients with blood group O are the hardest to match because blood type O is a universal donor but can only receive from the same blood type. On the other hand, blood group AB is the easiest to match because it is a universal recipient.

2) Human Leukocyte Antigen (HLA)

HLA is a typing which is called tissue typing is used to match patients and donors before transplantation. HLA are proteins located on the majority of your body’s cells to mark them as their own body cells, not a foreign body. Without these markers, your immune system would be unable to determine which cells belong in your body and which do not. Tissue typing is the second test performed during the evaluation process.

A “perfect match” kidney is one in which the recipient’s and donor’s markers are all the same. Perfect match transplants have the highest chance of lasting a long time and the lowest risk of rejection. mostly, siblings and first-degree relatives provide the most perfect match for kidney donations. The more mismatching between donor’s and recipient’s tissue markers, the more risk of failure of the transplantation.

3) Crossmatching

This is part of blood compatibility testing, it is simply applying the two previously mentioned ideas by a simple test. Crossmatching involves mixing a sample of the recipient’s blood plasma with a sample of the donor’s red blood cells. If the crossmatch is positive, it indicates that antibodies exist against the donor.

The recipient should not get this kidney unless a specific therapy to lower antibody levels is provided prior to transplantation. If the crossmatch is negative, it suggests that the receiver has no antibodies to the donor and is subsequently able to receive this kidney.

4) Miscellaneous Serological (Blood) Tests

These are conducted to exclude the presence of endemic, chronic, and potentially transmissible diseases. both the donor and the recipients should be tested for HBV, HCV, HIV, and CMV (cytomegalovirus).

Recovery

After surgery, patients are asked to stay in the hospital for 3 to 7 days to be observed closely. The post-operative phase requires careful monitoring of kidney functions, blood pressure, and vital signs. A healthcare professional should keep a close eye on the patients to notice early signs of acute rejection. A nephrologist will prescribe a few medications such as anti-inflammatory and anti-rejection drugs. Patients will also be asked to follow a diet plan suited to fit their condition.

The most crucial phase begins once you get back home from the hospital. You will need to have regular follow-up visits to your doctor to make sure your kidney is functioning well and you are getting the suitable dose of Immuno-suppressants, especially during the first year. you may get asked to get your blood tested multiple times every week. Then, you will make fewer visits, but only enough to ensure that your kidney is healthy. Never forget that recovery is a slowly progressing process. Patients who had kidney transplants are believed to take about 2 months to get almost recovered.

Complications & Risks

As with any major surgery, kidney transplantation has potential risks and complications which patients should be aware of before undergoing the operation. The complications that may result from kidney transplantation include those related to the procedure, rejection of the donor organ, and the side effects of taking immunosuppressants required to prevent your immune system from rejecting the donated kidney. Complications of kidney transplant occur mostly in the first 2 months of the surgery. However, we will discuss the short-term and long-term complications.

Short-term complications

Blood thrombus (clot) can form in the arteries that are supplying the donated kidney. The probability of occurrence of a significant thrombus is around one out of every 100 kidney transplants. The human body is usually capable of breaking down blood clots, otherwise, thrombolytic medications should be given to resolve these clots before blocking completely the blood supply of the kidney.
Infection is a probable complication, yet operation rooms nowadays are more equipped with sterilization tools reducing the risk of infection. Fortunately, most cases of infection such as UTI, pneumonia, and nephritis are manageable.
Kidney rejection is the most undesired outcome of any transplantation. Organ Rejection is when the recipient’s immune system thinks by mistake that the implanted organ is a foreign body and attacks it. Although anti-rejection medication is prescribed, rejection could just occur. Up to 30% of patients develop a degree of kidney rejection. Rejection could occur at any time after surgery, but it most commonly occurs shortly within the first six months after the procedure. Fortunately, kidney rejection could be reversed in most cases by appropriate management.
A blocked or leaking ureter is reported to be a postoperative complication of transplantation. A ureter is a 20 to 30 cm tube that transports urine from the kidney to the urinary bladder. For some reason, the ureter may get blocked after surgery but usually, it could be unblocked by inserting in it a hollow tube called a catheter.
Excessive bleeding due to vascular injury. Patients with bleeding tendencies and clotting disorders are more susceptible to bleeding during a kidney transplant.

Long-term Complications

Long-term complications are usually caused by disturbed kidney functions or side effects of immune-suppressive (anti-rejection) medications:

Hypertension (high blood pressure) is the most common long-term complication of a kidney transplant. Kidney functions include controlling blood pressure and maintaining it in the normal range. Hypertension in adults is defined as a blood pressure exceeding 140 / 90. Most patients with hypertension are asymptomatic or just complaining of mild headaches. Patients who just had kidney transplants should schedule follow-up appointments with their nephrologist to avoid risks of high blood pressure.
Cancer is the most serious side effect of immunosuppressants. Generally, patients taking immunosuppressants don’t develop tumors unless they are genetically susceptible. Studies showed that tumor-induced immunosuppression is reported after kidney transplant, these tumors include lymphoma, melanoma, and Kaposi sarcoma.
Osteoporosis is a medical condition in which the bone matrix gets less dense and weak. It is believed that osteoporosis is a side effect of anti-rejection drugs.
Weight and acne are less common side effects of immune suppression.

What happens during the Procedure?

The transplant procedure is carried out under general anesthesia, it takes normally 2-4 hours. A kidney transplant is a heterotopic transplant, which means that the kidney is put in a different location than the existing kidneys. The surgeon makes a 2-to-5-inch incision in the lower part of one side of the abdomen where the donated kidney is placed.

Then the surgeon connects the blood vessels of the donated kidney to the patients’ blood circulation. The ureter of the new kidney is also connected to the patient’s urinary bladder. Unless the patient’s own kidneys cause serious complications such as frequent infection, high blood pressure, kidney stones, or pain, the patient keeps it.

Contraindications

Who isn’t eligible to have a kidney transplant? Some patients are contraindicated to have kidney transplantation whether to avoid the potential complications of the surgery or risks of immunosuppression. Patients with temporary contraindication could have their surgery as soon as they are free of it, while untreatable contraindications are absolute, and their patients will have to stay on dialysis for the rest of their life. These contraindications are:

Active or recurring infection that is not fully resolved. Chronic infections such as HCV and HIV are no longer an absolute contraindication of transplantation, yet patients should be carefully evaluated first.
Chronic severe cardiovascular disease is expected to affect the outcome of the transplantation.
Malignancy and history of tumors are red flags for a kidney transplant. Doctors usually recommend not performing transplantation before appropriate treatment of the tumor. Research revealed that the rate of tumor recurrence is up to 50% if transplantation is performed within the period of tumor therapy.
Substance abuse can directly affect the outcome of the transplantation and compromise its results. Although substance abuse is a relative contraindication, Patients should be treated first for drug dependence before undergoing surgery.
Chronic lung disease cause impaired ventilation and oxygenation. Such conditions significantly reduce the life expectancy of the recipient and subsequently reduce his chances of getting a donated organ.
A bleeding disorder is a controllable medical condition, yet patients diagnosed with hyper or hypocoagulability shouldn’t undergo kidney transplants until treated.
Morbid obesity is a non-favorable condition for a kidney transplant.
Pregnancy is a controversial contraindication of a kidney transplant. Generally, doctors recommend performing surgery after delivery to avoid pre-term labor. Pregnant women with end-stage kidney disease are subjected to their nephrologist evaluation and decision.