vascular medicine

2

Arteriovenous malformation (AVM) is an abnormal connection between arteries and veins, bypassing the capillary system. This vascular anomaly is widely known because of its occurrence in the central nervous system, but can appear in any location. Although many AVMs are asymptomatic, they can cause intense pain or bleeding or lead to other serious medical problems.

An AVM lacks the dampening effect of capillaries on the blood flow, which means that the AVM can get progressively larger over time as the amount of blood flowing through it increases, forcing the heart to work harder to keep up with the extra blood flow. It also causes the surrounding area to be deprived of the functions of the capillaries — removal of CO2 and delivery of nutrients to the cells. The resulting tangle of blood vessels, often called a nidus (Latin for “nest”), has no capillaries. It can be extremely fragile and prone to bleeding because of the abnormally direct connections between high-pressure arteries and low-pressure veins. The resultant sign, audible via stethoscope, is a rhythmic, whooshing sound caused by excessively rapid blood flow through the arteries and veins. It has been given the term “bruit”, French for noise. On some occasions a patient with a brain AVM may become aware of the noise, which can compromise hearing and interfere with sleep in addition to causing psychological distress.

ABDOMINAL AORTIC ANEURYSM (AAA) - Overview and Surgical Procedure Explained In Text, Picture & Video

Overview:

The aorta is the largest artery in the body, it carries oxygen-rich blood pumped out of, or away from, your heart. The aorta runs through the chest, where it is called the thoracic aorta. When it reaches the abdomen, it is called the abdominal aorta. The abdominal aorta supplies blood to the lower part of the body. In the abdomen, just below the navel, the aorta splits into two branches, called the iliac arteries, which carry blood into each leg.

When a weak area of the abdominal aorta expands or bulges, it is called an abdominal aortic aneurysm (AAA). The pressure from blood flowing through the abdominal aorta can cause a weakened part of the aorta to bulge, much like a balloon. A normal aorta is about 1 inch in diameter. An AAA can stretch the aorta beyond its safety margin as it expands. Aneurysms are a health risk because they can burst or rupture. A ruptured aneurysm can cause severe internal bleeding, which can lead to shock or even death.

Less commonly, AAA can cause another serious health problem called embolization. Clots or debris can form inside the aneurysm and travel to blood vessels leading to other organs in the body. If one of these blood vessels becomes blocked, it can cause severe pain or even more serious problems, such as limb loss.

Each year, physicians diagnose approximately 200,000 people in the United States with AAA. Of those 200,000, nearly 15,000 may have AAA threatening enough to cause death from its rupture if not treated.
______________________

Surgical Procedure:

Open Repair: The conventional open surgical repair of aneurysms involves opening the abdominal cavity in the case of an abdominal aortic aneurysm, and sewing a synthetic graft inside the aneurysm to the artery above and below it to prevent the aneurysm from rupturing. In essence, relining the weakened aorta with a sleeve of material making the aorta stronger.

Endovascular Repair: A newer approach, called an endovascular repair, involves the use of a catheter that is inserted into the groin, in a similar fashion as an aortogram, however, the catheter is used to insert a self-expanding stent graft into the aneurysm. Endovascular repair of aneurysms does not require a large incision and has a substantially shorter recovery than the conventional open surgical approach. Not all aneurysms are suitable for endovascular repair.

______________________

Pictures:

_________________________

Video:

A saphenous vein graft was placed between the common and the internal carotid arteries. The pseudoaneurysm was isolated with a vascular clamp across the proximal common carotid artery and a clip was placed in the internal and external carotid arteries.