So she could have bled to death if you did surgery on her?
Dr. P. Roc Chen: That could be one issue. Secondly, if the brain is swollen it makes surgery extremely difficult and the surgical risk increases significantly. So the second way to do it is to use a catheter, meaning an endovascular technique, to find a way to navigate through certain blood vessel channels to get to the point where you can try to block the wrong connections. The way to block it is to use a certain liquid material. There are old materials available but now we have a newer technique using material that is similar to that, but has much better control: this Onyx “glue.” The way you inject it is to inject directly into the affected area and then watch as the liquid quickly solidifies and seals the entire blockage. Once sealed, we would be able to restore entire venous pressure. So that was the plan.
So what did you seal to make it work again?
Dr. P. Roc Chen: The DAVF (dural arteriovenous fistula), which basically blocks the venous outflow. Once you disconnect it, you reverse the entire outflow state. So even though she’s living with a limited outflow venous channel, she is much better off than when she had the continuously high pressure blood pumping into it. So that was the whole idea. A difficult part with her case was that her wrong connection, the dural AV fistula, was extremely diffused. Number two: because her outflow channel was almost completely cut off, it made it nearly impossible to access from a conventional route, to get to the point where we could try to seal those abnormal short circuits. So these were two difficult points that made this case much more troublesome. But in the end, we were able to find a way to navigate through the tiny arteries and use those tiny arteries to get to where we needed to go.
Can you use this on other people now?
Dr. P. Roc Chen: Yes. We’re using this same material for many patients who have a similar condition and arteriovenous malformations. Even in different concentrations, for short periods of time, they used it for brain aneurysm treatments, although the popularity has decreased recently. We also use it to reduce blood flow in cranial tumors prior to surgery to reduce surgical complications.
For more information, please contact:
P. Roc Chen, MD, FACS, FAANS
Mischer Neuroscience Institute