Kidney Dysplasia Causes and Treatment

The kidneys are a pair of bean-shaped organs that filter fluid and wastes from the blood to form urine. Urine flows from the kidneys to the bladder through tubes called ureters. Kidney dysplasia is a condition that can occur in babies while they are growing in the womb.

Other terms that health care providers and scientists use to describe this condition are renal dysplasia and multicystic dysplastic kidney (MCDK).

In kidney dysplasia, the internal structures of one or both of the baby’s kidneys do not develop normally. Fluid-filled sacs called cysts replace normal kidney tissue.

Kidney dysplasia usually happens in only one kidney. A baby with one working kidney can grow normally and has few, if any, health problems.

Babies with kidney dysplasia affecting both kidneys generally do not survive pregnancy, and those who do survive need dialysis and kidney transplant very early in life.

How does kidney dysplasia happen?

Ureters are tubes that grow into the kidneys and branch out to form a network of tubules that will collect urine when the fetus is developing in the womb.

In kidney dysplasia, the tubules fail to branch out completely. The urine that would normally flow through small tubules has nowhere to go, so it collects inside the affected kidney and forms cysts.

What are the signs or complications of kidney dysplasia?

The affected kidney may be enlarged at birth. Abnormalities in the urinary tract may lead to urinary tract infections. Children with kidney dysplasia may develop high blood pressure, but only rarely.

Children with kidney dysplasia may have a slightly increased risk for kidney cancer. Chronic kidney disease and kidney failure may develop if the child has urinary problems that affect the normal kidney.

Many children with kidney dysplasia in only one kidney have no signs or symptoms.

How is kidney dysplasia diagnosed?

Kidney dysplasia is often found during a fetal ultrasound, also called a sonogram, during pregnancy. Fetal ultrasound uses sound waves to create images of the baby growing in the womb.

However, the condition is not always detected before the baby is born.

After birth, an enlarged kidney may be detected during an examination for a urinary tract infection or other medical condition.

How is kidney dysplasia treated?

If the condition is limited to one kidney and the child has no symptoms, no treatment may be necessary. Regular checkups should include blood pressure measurements, blood tests to measure kidney function, and urine testing for protein.

Usually the child is monitored with periodic ultrasounds to look at the affected kidney and to make sure the other kidney continues to grow normally and doesn’t develop any other problems

. Children with urinary tract infections may need to take antibiotics.

Removal of the kidney should be considered only if the kidney

  • causes pain
  • causes high blood pressure
  • shows abnormal changes on ultrasound

What causes kidney dysplasia?

Kidney dysplasia may be caused by the mother’s exposure to certain drugs or by genetic factors. Pregnant women should talk with their health care providers before taking any medicine during their pregnancy.

Drugs that may cause kidney dysplasia include prescription medicines, such as drugs to treat seizures and blood pressure medicines called angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs).

A mother’s use of illegal drugs-such as cocaine-can also cause kidney dysplasia in her unborn child.

Kidney dysplasia can also have genetic causes. The disorder appears to be an autosomal dominant trait, which means one parent may pass the trait to a child.

When kidney dysplasia is discovered in a child, an ultrasound examination may reveal the condition in one of the parents.

Several genetic syndromes that affect other body systems may include kidney dysplasia as one part of the syndrome.

A syndrome is a group of symptoms or conditions that may seem unrelated but are thought to have the same cause-usually a genetic cause.

A baby with kidney dysplasia might also have problems of the digestive tract, nervous system, heart and blood vessels, muscles and skeleton, or other parts of the urinary tract.

What are the signs or complications of kidney dysplasia?

The affected kidney may be enlarged at birth. Abnormalities in the urinary tract may lead to urinary tract infections. Children with kidney dysplasia may develop high blood pressure, but only rarely.

Children with kidney dysplasia may have a slightly increased risk for kidney cancer. Chronic kidney disease and kidney failure may develop if the child has urinary problems that affect the normal kidney.

Many children with kidney dysplasia in only one kidney have no signs or symptoms.

How is kidney dysplasia diagnosed?

Kidney dysplasia is often found during a fetal ultrasound, also called a sonogram, during pregnancy. Fetal ultrasound uses sound waves to create images of the baby growing in the womb.

However, the condition is not always detected before the baby is born.

After birth, an enlarged kidney may be detected during an examination for a urinary tract infection or other medical condition.

Medical Care

The role of nephrectomy in multicystic dysplasia of the kidney (MCDK) is controversial. Prior to the availability of modern ultrasonography, nephrectomy was often required to establish the diagnosis.

A survey by Bloom et al revealed that 65% of pediatric urologists recommended nephrectomy for multicystic dysplastic kidney, compared with more recent data that indicate only 40% of pediatric urologists recommend nephrectomy.

The traditional reasons to consider nephrectomy are to treat or prevent abdominal or flank pain, urinary tract infection (UTI), hypertension, or renal malignancy.

If a child has significant abdominal or flank discomfort that can be attributed to the pressure effects of multicystic dysplastic kidney, the abnormal kidney should be removed.

If a child has evidence of a UTI, consider a nephrectomy only if the UTI involves the kidney with multicystic dysplastic kidney.

The presence of ipsilateral vesicoureteral reflux (VUR), pyelonephritis in the contralateral kidney, or recurrent episodes of cystitis are not sufficient justification for a nephrectomy in multicystic dysplastic kidney.

If a child has hypertension, consider a nephrectomy only if the hypertension can be shown to be due to the kidney with multicystic dysplastic kidney.

The presence of a renal malignancy is an indication for nephrectomy.

The main controversy regarding the indications for nephrectomy is whether this procedure prevents a renal malignancy.

Determining whether a renal malignancy is present in individuals with multicystic dysplastic kidney might be difficult.

The retroperitoneal location precludes physical detection of a small mass, and the lack of urine output from the affected kidney does not allow for cytologic examination.

The evidence for the presence of a renal malignancy must be based on diagnostic imaging changes, and because cysts can be noted in renal malignancy, differentiation might be difficult.

Beckwith’s mathematical analysis does not recommend nephrectomy based on the calculated incidence of Wilms tumor, but the calculation does not consider the incidence of renal carcinoma (see Complications).

Whether the risk of renal malignancy in those individuals who show involution is different compared with the risk in those who do not is unknown.

Some concern surrounds the possibility that the intervening stroma of a kidney affected by multicystic dysplastic kidney might not undergo complete involution and might provide a focus for malignant degeneration.

However, no increased risk of Wilms tumor has been demonstrated in patients with multicystic dysplastic kidney. A systemic review of 26 studies demonstrated no cases of Wilms tumor in 1041 children with unilateral multicystic dysplastic kidney.

These data are consistent with an earlier study by the American Multicystic Kidney Disease Registry that found no cases of renal neoplasia in 260 patients with multicystic dysplastic kidney.

Some authors recommend nephrectomy only in patients who do not show involution over a defined period, such as the first 5 years of life.

Because the peak incidence of Wilms tumor is in infancy and declines after age 5 years, this approach seems less scientific.

A poll of insurance companies revealed that only 15% issue life insurance if the multicystic dysplastic kidney–affected kidney is left in situ, compared with 70% if the kidney is removed.

The role of laparoscopic nephrectomy for multicystic dysplastic kidney is controversial.

Individuals with multicystic dysplastic kidney should undergo renal ultrasonography every 6-12 months until age 5 years or until involution is noted.

Individuals with multicystic dysplastic kidney and contralateral VUR should receive antibiotic prophylaxis during infancy and early childhood, the ages during which the risk for scarring due to pyelonephritis is highest. Miller et al reported on 75 children with multicystic dysplastic kidney.

Nineteen (26%) had VUR. After a median follow-up of 4.4 years, spontaneous resolution occurred in 89% of patients with grades I and II VUR, compared with only 50% of patients with grades III and IV VUR (P = .14). The presence of

VUR did not affect the sonographically measured growth of the contralateral kidney.

Lifetime follow-up is required whether or not involution has occurred or a nephrectomy has been performed because long-term studies of patients with a single kidney report hypertension in 27-47% of patients, proteinuria in 23-47% of patients, and renal insufficiency in 3-13% of patients.

Sporadic clinical reports have documented the development of proteinuria and focal glomerulosclerosis in patients with a single kidney.

Follow-up should include routine and ambulatory measurement of the blood pressure, urinalysis, and periodic assessments of kidney filter function.

The presence of associated urinary and nonurinary abnormalities might require specific follow-up.

Source & More Info: Medicine Net and E Medicine

>>VIDEO

.

Leave a Comment