Hereditary hemorrhagic telangiectasia (HHT) is a genetic disorder
that affects about one in 5,000 people and causes arterial blood to
flow directly into the veins, creating weakened ballooned vessels that
can rupture. Interventional radiologists are one of the few
specialists who can permanently treat this disease that affects
approximately half a million people worldwide. As vascular experts,
interventional radiologists perform embolization - blocking the blood
flow to the affected area - to prevent a life-threatening rupture.
Most patients with HHT function normally and 40 percent have brain
or lung involvement that may lead to unexpected severe complications.
Physicians treating complications often don't realize that the
underlying disorder is HHT. As a result, most patients are undiagnosed.
Overview of circulatory system and HHT
In the normal circulatory system, arteries take oxygenated blood
from the heart and push it out to all parts of the body under high
pressure, while the veins return the blood back to the heart. Small
capillaries typically connect the arteries to the veins. A person with
HHT lacks capillaries in a few blood vessels in critical locations.
Arteries connect directly into veins, creating a fragile site that can
rupture and bleed. These abnormal blood vessels are called
telangiectasis if they involve small blood vessels (nose, stomach and
small bowel) and arterioveneous malformations (AVM) if it involves a
larger blood vessel (lung, brain and liver). Telangiectases often
occur near the surface of the skin like the mucous membrane in the
nose while AVMs appear in the internal organs of the body.