Although renovascular diseases most often affect the elderly (and men), they can affect young women (generally those under forty) with a type of renovascular disease called fibromuscular dysplasia--which can cause severe high blood pressure. In general, renovascular conditions are diseases and disorders which affects the arteries and veins that carry blood to and from the kidneys. As the condition progresses, the blood vessels narrow or become blocked. The kidneys work as filters, removing waste material (impurities) from blood. The renal arteries carry blood into the kidneys and the filtered blood then flows out and to the rest of the body via the veins.
Common Conditions
In renal artery stenosis, the artery carrying blood into a kidney has narrowed, as opposed to renal artery occlusion in which one or both of the renal arteries has become blocked. In renal vein thrombosis, the renal veins are blocked. Renal atheroembolism affects the renal arterioles--the smallest segment of the blood vessel which feeds the capillaries. Arterial nephrosclerosis results from inflammation and cell death occurring in the renal arteries. And scleroderma renal disease is a complication of a skin disorder which has caused lesions in the arteries.
Symptoms
Because the condition generally progresses over time, there are no early warning signs; so the disease might not be diagnosed until after damage has been done. This can be especially true if the blockage is only affecting one kidney--as the other kidney is capable of doing the work for two.
In renal artery occlusion and renal vein thrombosis, when both kidneys are blocked suddenly, a person might experience back or side pain, blood in the urine, fever, nausea or vomiting. In the case of complete blockage, there might be no urine at all. With renal atheroembolism, there is a chance of having embolisms elsewhere in the body--such as in the retina.
As renovascular conditions progress, high blood pressure may appear, along with signs of kidney failure. Kidney failure symptoms include: a bad taste in the mouth, chest pain, anxiety or confusion, fatigue, itchy skin, loss of appetite and weight loss, muscle spasms or cramps, nausea, vomiting, pale or yellow-brown tinged skin and puffy (or swollen) eyes, hands and feet.
Causes
For renal artery occlusion, the problem can be an embolism totally or partially blocking an artery. An embolism (a blood clot or foreign substance in the blood) can be caused by surgery, trauma, heart disease or tumors. Yet most renovasuclar conditions are caused by artherosclerosis (hardening of the arteries) which results from cholesterol, calcium or another substances lining the artery wall.
Renal vein thrombosis is a less common occurrence. But an embolism can be caused by an injury to the back or abdomen. Nephrotic syndrome (or other kidney-related conditions) can also cause an embolism.
Artherosclerosis is the cause of renal atheroembolism. Risk factors for atheroembolism include: a family history of the condition, diabetes, high blood pressure, heart disease, high cholesterol, obesity and smoking.
Treatment
There is no treatment for renal atheroembolism. The goal is to keep the condition from worsening. So as with any renovasuclar condition, the plan is to keep blood pressure down and control diabetes. As well as eating healthy (reducing fat intake) and drinking plenty of fluids can help.
For renal artery and vein blockages, doctors have a number of treatments. In severe cases, doctors may use surgery to clean out the blockage. This is more likely to occur when the blockage is the result of some trauma rather than a disease. But if there is only a partial blockage, doctors may use balloon angioplasty or renal artery bypass surgery to improve kidney function.
Doctors may also deal with the blood clots by dissolving them with drugs called thrombolytics--such as streptokinase and urokinase. But this sort of treatment can only be done if the vein or artery is not completely blocked and the condition is treated soon after the blockage. Anticoagulants--such as warfarin or heparin--may be used to prevent further blood clots from forming and causing future blockage.
When a kidney becomes completely blocked, it is important to treat it immediately. Kidney tissue cannot survive for more than three hours without blood flow.
Additional Complications
With the high blood pressure generally caused by renovascular disease comes damage to blood vessels. There can also be congestive heart failure, heart attacks, strokes, loss of vision and kidney damage or failure. Pulmonary embolisms are possible with renal vein thrombosis in the event the blood clots move from the kidneys to the lungs.
Tags: renal artery, blood pressure, high blood, high blood pressure, vein thrombosis, artery occlusion