AVMS before medical intervention:
AVM after medical intervention. The bulge isn't gone but is greatly reduced. The circle by the pointer is where a small coil was inserted. The blood literally clots off the blood flow past that point. Other treatments include the use of small particles that block the blood flow, used in areas where it is too small or hard to get to.
An arteriovenous fistula is an abnormal channel or passage between an artery and a vein.
An arteriovenous fistula is a disruption of the normal blood flow pattern. Normally, oxygenated blood flows to the tissue through arteries and capillaries. Following the release of oxygen in the tissues, the blood returns to the heart in veins. An arteriovenous fistula is an abnormal connection of an artery and a vein. The blood bypasses the capillaries and tissues, and returns to the heart. Arterial blood has a higher blood pressure than veins and causes swelling of veins involved in a fistula. Although both the artery and the vein retain their normal connections, the new opening between the two will cause some arterial blood to shunt into the vein because of the blood pressure difference. (What the shunting means is that the blood returns to the heart too quickly, not giving the blood time to accomplish the exchange of oxgyen and carbon dioxide.)
Fiona does not have this diagnosis because she doesn't have the platypnea (trouble breathing when laying down), clubbing (fingertips flatten out), cyanosis (turning blue), hypoxia (not enough oxgyen), and orthodeoxia (oxygen levels change with position of the body). On 100% oxygen everything is just fine. With HPS is doesn't improve with oxygen. All her pulmonary function tests are normal or near normal except the exchange test that is abnormal. She has a VERY positive bubble echo test, showing a great deal of shunting. She does have dyspnea or shortness of breath and she gets chest pains that are otherwise unexplainable.
Hepatopulmonary syndrome (HPS), increased alveolar-arterial oxygen gradient, and intrapulmonary right-to-left shunting (defined as the triad of liver disease) may occur in as many as 47% of patients with end-stage liver disease. All types of chronic liver disease may give rise to this syndrome. Approximately 80% of affected patients have signs and symptoms of end-stage liver disease before symptoms from PAVMs develop. These patients have dyspnea, platypnea, clubbing, cyanosis, hypoxia, and orthodeoxia. Pulmonary function results indicate normal lung volumes and expiratory flow rates with low diffusing capacity.
She also doesn't have Osler-Weber-Rendu syndrome or HHT. Fiona has been thoroughly examined for AVMs on her skin, nose, mouth and in her brain. All her "red spots" on her skin are on her arms, hands, legs and chest; typical of a liver patient. There is no sign at this time that she has Osler-Weber-Rendu syndrome for HHT. If this comes up again, they can do genetic testing to rule it.
HHT is a genetic disorder that causes abnormalities of blood vessels. Most blood vessels in the body of someone with HHT are normal. However, a small percentage of the blood vessels in a person with HHT have a specific type of abnormality.
Blood vessels are the tubes that carry blood around our bodies. There are two types of blood vessels: arteries and veins. Arteries carry blood under high pressure out to all areas of the body after being pumped by the heart. Veins carry blood that should be under low pressure, back to the heart. An artery does not usually connect directly to a vein. Usually there are very small blood vessels called capillaries that connect an artery to a vein.
A person with HHT has a tendency to form blood vessels that lack the capillaries between an artery and vein. This means that arterial blood under high pressure flows directly into a vein without first having to squeeze through the very small capillaries. This place where an artery is connected directly to a vein tends to be a fragile site that can rupture and result in bleeding. We usually call a blood vessel that is abnormal in this way a telangiectasia (tel-AN-jee-eck-TAZE-ee-ya), if it involves small blood vessels. We tend to call it an arteriovenous malformation (AVM) if involves larger blood vessels. So, an AVM might be thought of as a big telangiectasia. The basic abnormality in the blood vessel is the same.
Telangiectases tend to occur at the surface of the body such as the skin and the mucous membrane that lines the nose. AVMs tend to occur in the internal organs of the body. The telangiectases (plural for telangiectasia) and AVMs of HHT occur primarily in the nose, skin of the face, hands, and mouth and the lining of the stomach and intestines (GI tract), lungs, liver and brain. It is not currently known why these abnormal blood vessels tend to occur in certain parts of the body and not others.
In speaking with the pulmonologist Friday, we once again asked if this was heptopulmonary syndrome or at least a non-standard version. He said no. In fact, he continued to say that Fiona is just progressing in a very unusual manners with the lung involvement. Her oxygen levels are good except on the oxygen-exchange test. She has no clubbing of the fingers, change in oxygen levels between laying down, sitting up and standing are good. She is not a typical anything. The pulmonary AVMs she has had for at least 2 years have never explained all the breathing difficulties, shortness of breath, feeling like she is going to pass out (she has passed out twice) or the chest pains. She has developed a very fast heart rate too, which she has had 2 heart caths and 2 lung caths done. For right now, he still thinks the liver is causing the problems because she didn't have problems as a young child and this beginning to progress faster in the last year. Once again, the doctors simply don't know how to explain all of this. So all our cards are waiting to be viewed by UCLA and hopefully this time they will be able to make some sense of all of this and give us direction.
Peggy
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