A vast and intricate network composes the inner workings of the human body's blood vascular system. As sophisticated as our vascular system is, the weakening of blood vessel walls give rise to an aneurysm, a balloon that grows from a blood vessel and continues to grow as more blood flows through, eventually reaching a size where it may rupture.
Dr. Fady Charbel, professor and head of the Neurosurgery Department at UIC Medical Center, described an aneurysm with a bubblegum analogy: "Imagine you're blowing a [bubble with] bubble gum. When you blow a bubble, the bubble may burst right away or it may take a while until the bubble is really thin and really large for it to burst."
Although an aneurysm may not rupture right away, the larger the aneurysm grows, the higher risk there is for it to explode.
Nancy Bell, a former firefighter from Twin Lakes, was diagnosed with a cerebral aneurysm after experiencing blurred vision, severe headaches and pain in her left eye. Despite previous procedures aimed at sealing off blood flow from her aneurysm, her problems persisted.
Bell's aneurysm would be a typical candidate for a standard bypass procedure wherein the aneurysm is clamped off at either side, a grafted blood vessel (usually the Great Saphenous vein from the patient's leg) is sutured on either end of the recipient blood vessel (the artery with the aneurysm), and then the ends of the blood vessel would be sutured to reroute the blood flow away from the aneurysm.
Because this procedure temporarily cuts off blood supply, the patient is at risk for a stroke (cutting off blood supply clots blood and when blood flow resumes, the clotted blood could dislodge), and there could also be tissue damage from the momentary disruption of blood flow.
The standard bypass is high-risk, especially when this type of aneurysm is in the brain.
However, Dr. Charbel had the answer for Bell's medical problem. ELANA (Excimer Laser Assisted Nonocclusive Anastomosis) was developed by neurosurgeon Cornellius Tulleken in the Netherlands in the 1990s. "Anastomosis" refers to the connection of blood vascular networks that are not normally joined. Bell was treated by Dr. Charbel and was the first patient to receive this experimental procedure in the Midwest.
Remember that the standard bypass procedure involved clamping, grafting then stitching. ELANA requires no clamping - meaning no disrupted blood flow. Instead, ELANA grafts a donor blood vessel and sutures this on top of the recipient blood vessel, on either end of the aneurysm. Once this is accomplished, a laser is inserted into the grafted vessel in order to bore a hole into the recipient vessel. In this way, blood flow is rerouted from passing underneath the aneurysm to flowing through the new donor vein. The grafted veins are then sutured together, creating a bypass surrounding the aneurysm.
"We don't usually remove the aneurysm. Say you have a bad bridge - you can leave that bridge alone and build a new one and block the traffic on the old bridge. It doesn't get used and the new bridge takes over," Dr. Charbel analogized.
Although it is still unknown why aneurysms form, doctors know that aneurysms form in "areas of stress - bifurcations [points where vessels split], around bends - where blood pulsation increases and the stress on the vessel is higher," explained Dr. Charbel. High stress on vessel walls causes a weak point in the artery which inevitably leads to a ballooning in one area of the vessel - this is the formation of the aneurysm.
Veins have thinner walls while arterial walls are usually thicker and more durable because of the higher pressure of blood flow, and because of this, arteries are the only blood vessels where aneurysms form. Grafted blood vessels, however, are almost always veins. Why not graft arteries if their walls are more durable and would probably prevent weakening of vessel walls?
Dr. Charbel reasoned that "arteries are precious. Veins are more common. Sometimes surgeons will use the radial artery, but it's usually the Saphenous vein that gets harvested."
Although ELANA is still an experimental procedure, Dr. Charbel feels that there is a good possibility that this new procedure could replace the standard bypass surgery. Even if patients could be offered both the standard bypass procedure and the new ELANA procedure, wouldn't the newly-developed laser surgery be more costly for the patient? "If there's less risk, it's less costly," said Dr. Charbel.
In healthcare, the benefits should always outweigh the costs. Fortunately, in the case of patients with cerebral aneurysms, while their options were limited prior to the development of ELANA, they are now given options with benefits that could and would outweigh both financial and health costs.
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