Rush University Medical Center will be the first in Chicago and among the first hospitals in the nation to offer a promising new treatment for arterio-venous malformations (AVMs) following its approval by the FDA on July 21.
Onyx Liquid Embolic is a sealant to block abnormal connections between veins and arteries in the brain using minimally invasive endovascular techniques.
As a result of high blood flow and pressure imbalances, AVMs in the brain are at risk of hemorrhage, or rupture, which can lead to stroke, severe disability and even death. Onyx is a liquid polymer that fills the AVM to seal it off and reduce the risk of bleeding or rupture. The minimally invasive procedure involves snaking a catheter through the blood vessels in a very controlled manner to deliver the embolic liquid to the tangled web of abnormal arteries and veins.
"Onyx is a vast improvement over previous embolization substances which would harden too quickly requiring a number of treatment sessions to achieve AVM occlusion," said Dr. Demetrius Lopes, a neuroendovascular specialist at Rush and a member of the Chicago Institute of Neurosurgery and Neuroresearch medical group (CINN).
"Onyx is a welcome addition to the treatment of AVM in the brain. It can be of use for patients who are deemed too risky for surgery or as an adjuvant to prior radiosurgery and open surgery," said Lopes. "Endovascular embolization can reduce the size and vascularity of the AVM, thereby facilitating safer and easier surgical resection."
Patients with AVMs have a 3 to 4 percent risk per year of hemorrhage from their AVM. When a patient suffers such a bleed, there is a 10% chance of dying, and a 20% chance of a stroke and permanent neurologic problems.
AVMs are believed to be congenital and are formed prior to birth. Approximately 80 percent of the estimated 300,000 Americans with AVMs will experience few, if any, symptoms. Those who do experience symptoms vary greatly in severity. In addition to seizures and headaches, AVMs can also cause a wide range of neurological problems such a muscle weakness, loss of coordination, dizziness, memory deficits, and mental confusion.