Evolution of Brain Surgery to Treat Rogue Blood Vessels

Over three decades, a world-recognized medical team at UC San Diego Medical Center has spurred the evolution of a complex surgery to destroy dangerous clusters of arteries and veins in the brain. Integrating innovative approaches in radiology, anesthesia, and surgery, the team has perfected a method to systematically starve these abnormal brain lesions, artery by artery, vein by vein.

“In the late 70s and early 80s, medical teams attempted to remove these lesions during a single surgery, frequently encountering catastrophic episodes of brain swelling,” said John C. Drummond, MD, professor and anesthesiologist at UC San Diego Medical Center. “Today, with a combination of embolization, the use of a medical coma, and staging shorter surgeries, patients experience consistently good outcomes.”

The brain lesion, called an arteriovenous malformation (AVM), ranges in size from less than one to 10 centimeters in diameter. The defect can also occur in the spinal cord, and affects more than 300,000 Americans per year. While many patients show no signs of the abnormality, more than 10 percent experience debilitating symptoms. The untreated lesion can be fatal.

“The malformation looks like a wild tangle of snarled blood vessels,” said Hoi Sang “Ben” U, MD, professor and neurosurgeon at UC San Diego Medical Center. “The clustering of arteries and veins deprives the rest of the brain of blood. Risks range from painful lingering headaches to massive hemorrhage.”

As a “living” lesion that monopolizes the brain’s blood supply, the malformation is difficult to remove. Capable of recruiting blood supplies from other vessels, the abnormality is stubborn, like a tumor, and will grow back if it is not entirely removed.

In the early days of the procedure, the UC San Diego surgical team was faced with removing the growth while protecting the brain from a sudden, potentially dangerous shift in blood flow.

Reducing Blood Flow

“It wasn’t until the 80s that AVMs were addressed by radiologists as a way of pre-treating a patient to improve the results of surgery,” said Scott Olson, MD, assistant clinical professor and radiologist at UC San Diego Medical Center. “Now, using catheter-based technology, we can often shut down 50-80 percent of the blood vessels that feed the AVM. With 3D rotational imaging, thinner and more flexible catheters, and new liquid embolic agents that better penetrate the lesion, we can more accurately target and eliminate the vessels that lead into the AVM.”

Prior to surgery, neuroradiologists attack the growth by embolizing, or plugging up, abnormal blood channels with particles of glue. During the process, a thin catheter is threaded through the leg’s femoral artery and up into the brain. Once inside the brain, the catheter weaves through tiny vessels, often curving in hair pin turns, before reaching the center of the AVM. The neuroradiologist must be able to visualize the growth in a three dimensional space, making anterior and posterior turns that are only millimeters in length.