What is Visceral Ultrasound?
Visceral ultrasound is the process of using high-pitched
sound waves to study the blood vessels of the renal arteries.
An ultrasound image is a useful way of evaluating the body's
circulatory system.
Ultrasound images are captured in real-time, so they can
help monitor the blood flow to organs and tissues throughout
the body, as well as evaluate the placement and success of
repair, such as arterial bypass surgery.
Ultrasound images help identify blockages (stenosis) and
abnormalities like blood clots, plaque or emboli and help
plan for their effective treatment.
What are Renal Arteries?
The renal arteries are vessels that carry blood to the
kidneys. These arteries can become obstructed, causing
reductions in blood flow to the kidneys which can often result in
hypertension (high blood pressure) and loss of kidney function.
The three diseases most likely to cause renal artery blockages are:
Developmental narrowings, occurring during fetal growth (before birth).
Fibrodysplasia, being abnormal scar tissue encroaching on the interior of the artery, invariably affecting women less than
45 years old.
Arteriosclerosis with cholesterol and plaque build-up, similar to that seen in the coronary arteries of the heart, the
carotid arteries to the brain, and the leg vessels. The most common age at diagnosis is 55 years. Men are affected twice
as often as women.
When these blockages become severe, the kidney releases a substance (a hormone called renin) that enters the blood stream and narrows all of the smaller vessels in the body. This causes the blood pressure to rise (renovascular hypertension). In addition when the blockages progress the kidney has difficulty in clearing the body's waste products and kidney failure may occur. The manifestations of renovascular hypertension are:
High blood pressure that is difficult to treat with medicines, especially in childhood and women less than 45 years
of age.
Deterioration of the kidney's ability to clear the body's waste products when high blood pressure medicines are
needed, especially ACE inhibitors like Captopril.
Unaccountable nose bleeds (epistaxis), ringing in the ears (tinnitus), and headaches early in the morning involving
the back of the head (occipital cephalgia). These are manifestations of severe hypertension.
If untreated, renovascular hypertension may contribute to a number of serious cardiovascular and kidney problems, including:
Stroke.
Thickening of the heart muscle (hypertrophy) to the degree that the heart becomes "muscle bound" and heart
failure evolves.
Acceleration of arteriosclerosis (hardening of the arteries) in all of the body's arteries. Thus increasing the risk of
stroke, heart attacks, aneurysms, and other vascular disease.
Renal failure requiring dialysis.
What is Mesenteric Disease?
The mesenteric arteries supply blood to the large and small intestines.
Ischemia (restriction of blood supply) occurs when blood cannot flow through
the arteries as well as it should, and the intestines do not receive the
necessary oxygen to perform normally. Mesenteric ischemia usually involves
the small intestine.
Mesenteric ischemia occurs when one or more of the mesenteric arteries
narrows or becomes blocked. When this blockage occurs, patients can
experience severe abdominal pain and, over time, the blockage causes
tissues in your intestine to die because they lack enough blood flow.
Mesenteric ischemia oftentimes occurs in people 60 years or older.
Patients who smoke or have a high cholesterol level may be more likely to
experience mesenteric ischemia.
Mesenteric ischemia can be either chronic or acute. Chronic means the
condition and symptoms have been lingering over a relatively long period of
time. Acute means the symptoms begin abruptly and become serious in a
very short period of time. Chronic mesenteric ischemia can progress quickly,
without warning, to acute mesenteric ischemia.
What are the Symptoms?
Chronic mesenteric ischemia may cause severe pain in the abdomen 15 to 60 minutes after eating. The pain can occur in any part of the abdomen, but most commonly in the middle to upper part. The pain may last for as long as 60 to 90 minutes and then disappear. Unfortunately, it may return the next time you eat. Many people with chronic mesenteric ischemia begin losing weight because, although they may feel hungry, they do not want to eat because they experience the pain.
Symptoms of chronic mesenteric ischemia can sometimes be vague and can be similar to those of other conditions. In addition to abdominal pain and weight loss, other symptoms that you might experience include:
Diarrhea;
Nausea
Vomiting
Flatulence or
Constipation.
With acute mesenteric ischemia, patients may experience sudden and severe stomach pain. Narcotic pain medications may not adequately alleviate the pain associated with mesenteric ischemia. With acute mesenteric ischemia, you may also experience nausea or vomiting.
What Causes Mesenteric Ischemia?
Atherosclerosis, which slows the amount blood flowing through your arteries, is a frequent cause of chronic mesenteric ischemia. Your arteries are normally smooth and unobstructed on the inside, but as you age, a sticky substance called plaque forms in the walls of your arteries. Plaque is made of fats and other materials circulating in your blood. As more plaque builds up, your arteries can narrow and stiffen. Eventually, enough plaque builds up to reduce blood flow through your arteries.
A clot, called an embolus, which travels to one of the mesenteric arteries and suddenly blocks the blood flow, is a common cause for acute mesenteric ischemia. These clots often originate in the heart and are more common among patients with an irregular heartbeat or heart disease.
Other conditions that may lead to mesenteric ischemia include:
Low blood pressure
Congestive heart failure
Aortic dissection, which is a tear in the aorta's inner layer; or
Occlusion or blockage of the veins in the bowel, or '
Coagulation disorders
Mesenteric ischemia is a serious condition that may come on and worsen quickly. It is extremely important that you go to your physician or the emergency room if you experience any of the symptoms.
