Cystic kidney disease consists of a group of similar (heterogeneous) disorders that result in the development of cysts on the kidney. The cysts are irregular sacs that can be filled with gases, fluids, or solids. If microscopic, treatment may not be necessary. But, if quite large and impacting the function of one (unilateral) or both (bilateral) kidneys, surgery and dialysis are two viable options. While the kidneys are mainly affected in cystic kidney disease disorders, the liver is may too be impacted, showing enlargement and damage.
Cystic Kidney Disease Treatable Symptoms
No drugs can treat cystic kidney disease directly. Instead, treatment (often lifelong) aims to ease symptoms, slow the progress of kidney failure, and prolong life. Treatable symptoms include:
- Pulmonary hypoplasia: With autosomal recessive polycystic kidney disease (ARPKD), if the mother shows low levels of amniotic fluid during pregnancy, there is an increased likelihood the baby will have underdeveloped lungs (pulmonary hypoplasia). In the most serious cases, the mother may be injected with betamethasone (a steroid with anti-inflammatory and immunosuppressive properties) during pregnancy to help stimulate lung development. After birth, newborns are given supportive therapy, including being put on a ventilator to assist breathing. They may also be given a surfactant, a drug that helps prevent the collapse of the tiny air sacs directly involved in oxygen exchange between the lungs and the blood. Despite these treatments, doctors have great difficulty treating pulmonary hypoplasia in babies with ARPKD. Fewer than 50 percent of babies with ARPKD and pulmonary hypoplasia live more than a week.
- High blood pressure: Controlling blood pressure, often with a multi-drug regimen like angiotensin-converting enzyme inhibitors and angiotensin receptor blockers, can help slow kidney damage and the disease’s progression. Lifestyle choices such as exercising, eating a healthful diet, and not smoking can also help manage blood pressure as well.
- Delayed or slow development: Because kidney function is essential to early physical development, children with ARPKD often have growth problems and are smaller than average. In general, this problem is treated with a high-calorie, nutritious diet. Recent studies suggest that maintaining nutrition is more important in managing ARPKD than limiting protein intake. The kidney enlargement seen in ARPKD often leads to early gastric satiety (feeling full quickly) and gastric reflux, which can inhibit appetite and physical development. A dietician may recommend supplements such as vitamin D and iron. In some cases, injections of human growth hormone (HGH) can be used to stimulate growth. And in rare instances, children with ARPKD may need to have meals supplemented with a feeding tube.
- Edema: One of the less severe symptoms of cystic kidney disease is edema or swelling, caused by decreased efficiency of the kidneys. Limiting salt consumption and taking a loop diuretic (which helps increase urine output) can help manage this symptom.
- Pain: Chronic pain, caused by expended tissue around the kidney or infected or bleeding cysts, is common in cystic kidney diseases. Mild back or flank pain can be treated with over-the-counter drugs like ibuprofen or acetaminophen, but doses may need to be monitored carefully since some types of cystic kidney disease can also cause liver problems. In cysts are large and painful, a doctor may suggest surgery to drain or remove them.
- Infections: Frequent cyst or urinary tract infections are a common symptom and are often treated with antibiotics to kill bacteria and inhibit their growth. If urinary tract infections (UTIs) occur regularly, a doctor may prescribe a regular, low dose of preventive antibiotics. If cysts become infected, the recommended treatment is usually lipid-soluble antimicrobials.
- Anemia: Children with chronic kidney disease may also develop anemia, or low red blood-cell count. This is initially treated with iron supplements. If it becomes critical, blood transfusions or injections of erythropoietin, the hormone that stimulates red blood cell formation, may be necessary.
- High phosphate levels: Excessively high phosphate levels can cause calcium to leach out of bones. This can lead to rickets, poor growth, and bone fractures. Phosphate binders can help prevent the buildup of excess phosphate in the blood.
Cystic Kidney Disease Dialysis
As kidney function declines, people with cystic kidney disease may require dialysis to remove the wastes that the kidneys normally filter out of the blood. Many patients remain on dialysis on a long-term basis, sometimes for the rest of their lives. Usually this takes the form of hemodialysis, in which blood is transferred from the body into a dialysis machine that then filters out waste products and excess fluids. The filtered blood is returned to the body. Hemodialysis is usually done in an outpatient center three times a week, with each session lasting about four hours.
Cystic Kidney Disease Surgery
Surgery can be used to drain infected or painful kidney cysts, to create access points for dialysis, or to remove and replace the kidneys and/or liver.
- Drainage: For patients with pain that cannot be managed with drugs, enlarged and painful cysts can be drained by percutaneous aspiration, sclerotherapy with alcohol or, seldom, surgical drainage.
- Dialysis access: In preparation for dialysis, peritoneal dialysis (PD) surgery or arteriovenous (AV) fistula surgery may be performed. With PD surgery, a small incision is made in the abdomen so that a catheter tube can be inserted into the cavity, which allows dialysis fluid to enter. With AV surgery, an artery and vein in the forearm are connected to increase blood flow.
- Transplantation: If total kidney failure occurs and dialysis fails, a patient will need a kidney transplant. A large incision is made in the lower abdomen. If possible, the patient’s own kidneys are left in place and the donor kidney is connected to the arteries and veins in the lower abdomen. But if the kidneys are extremely enlarged or have had multiple infected cysts, they must be removed (a process called nephrectomy). Children with hereditary types of cystic kidney disease, like ARPKD, also develop some amount of liver scarring. If it's severe, liver function degrades and a combined liver/kidney transplant may be required.
Cystic Kidney Disease Prognosis
Prognosis for cystic kidney disease depends on the type of associated disorder and its severity. For example, with ARPKD, between 20-30 percent of infant patients die within the first few hours or days of birth, mainly due to breathing complications caused by having underdeveloped lungs, an attribution to a deficiency of amniotic fluid in the womb. Those who reach age 10 most often have kidney failure and require dialysis or transplantation, and those who survive to adulthood also develop kidney failure along with congenital hepatic fibrosis and bile duct expansion. Additionally, the liver may be enlarged, damaged, and have cysts.
Those with autosomal dominant polycystic kidney disease (ADPKD), clinical symptoms do not usually appear until the age of 30. Still, approximately 50 percent will develop kidney failure and enter end-stage kidney disease between the age of 57-73. Despite this, most deaths are caused by cardiovasular complications and infections, making timely treatment necessary to allay the symptoms and slow the progression of the disease.
References
Palmer, J.S., ed. (2011). Pediatric urology: A general urologist’s guide. Humana Press.
Bisceglia, M., et al. (2006). Renal cystic diseases: a review. Advances in Anatomic Pathology.
