Overcoming Brain Injury and AVM: Tyler’s Story of Survival

On April 10, 2023, Tyler Herrell went to work as usual. As a CDL driver, most of his time was spent driving but, on this day, he was working alone, pouring concrete. When his coworker turned up hours later, Tyler was unconscious, and worse — he’d hit his head on a rock as he fell.

Tyler was taken straight to the emergency room where he had brain scans. He had a fractured skull and an epidural hematoma. This is a dangerous condition in which arterial blood collects between the skull and the brain’s outer layer, potentially resulting in life-threatening increases in pressure on the brain. He needed emergency surgery.

The Fracture

Tyler was transferred to OU Health University of Oklahoma Medical Center and placed under the care of Dr. Christopher Graffeo, M.D., M.S., a cranial neurosurgeon and assistant professor in the Department of Neurosurgery at the University of Oklahoma College of Medicine.

Dr. Graffeo opened Tyler’s scalp and skull to raise the fracture fragment, remove the hematoma, and reconstruct the skull using titanium mini-plates and screws.

During the workup for his injury and just prior to the operation, Dr. Graffeo discovered that Tyler’s brain harbored an arteriovenous malformation (AVM).

A Hidden Danger

Dr. Graffeo explained that brain AVMs are typically congenital lesions, in which arteries connect directly to veins without the usual tiny blood vessels (capillaries) in between, which is called “shunting.” This is dangerous because veins, which normally handle low pressure, are exposed to high arterial pressure.

Over time, this may cause the veins to rupture, resulting in a stroke. Other AVMs siphon blood flow away from the adjacent healthy brain, resulting in seizures or other neurological symptoms.

Brain AVMs are rare, occurring in less than 1% of the population. They typically present with headache, seizure, or a new neurological deficit from a seizure — although many AVMs today are found by accident during unrelated imaging.

Key Points:

• What happens: Blood flows directly from arteries to veins without passing through the tiny vessels (capillaries) that normally slow it down and deliver oxygen to brain tissue.
• Symptoms: Many patients with AVM develop headaches or seizures. If the AVM ruptures, bleeding into the brain may result in a stroke-like functional deficit.
• Cause: The exact cause is unknown, but most AVM patients are born with these abnormal blood vessels.
• Treatment: Options include microsurgical resection with or without embolization, or stereotactic radiosurgery (also known as gamma knife); observation without intervention is also appropriate for some patients.

Tyler needed to have surgery to remove the AVM, but first, he needed to recover from the surgical repair from the skull fracture and epidural hematoma.

“I planned the initial operation for the fracture and hematoma in a way that allowed us to use the same incision,” explained Dr. Graffeo. “Since he was an otherwise young healthy man with a large AVM in a relatively safe location, our recommendation was to proceed with removing the AVM since that is the more definitive treatment. However, we thought it would be safer to stage the operations, so that he would have time to recover before undergoing the AVM resection, which can be a daunting recovery on its own.”

Removal of the AVM

A month after Tyler had surgery to repair his skull, he had a cerebral angiogram. A cerebral angiogram is a minor procedure that uses a contrast dye to show detailed images of the blood vessels and the abnormal blood flow through the AVM. It is performed by physicians with interventional neuroradiology training. The procedure is important for AVM treatment planning and may also be used for other diagnostic workups or treatments, such as cerebral aneurysms, fistulas, or certain brain tumors. Angiograms show blood flow in real time, which is not possible using any other imaging technique, such as an MRI or CT scan.

The main goal of treating arteriovenous malformations (AVMs) is to stop the abnormal connection between arteries and veins while keeping nearby brain tissue healthy. Surgery is the most direct way to do this by removing the AVM entirely, but it carries higher risks and is usually reserved for AVMs that are easy to reach or have already caused bleeding. Radiosurgery, on the other hand, is a non-invasive option that uses focused radiation to gradually close off the AVM. It’s safer and less invasive but may take longer to work and isn’t always successful, sometimes requiring follow-up surgery or another round of radiation

On May 12, 2023, Dr. Graffeo performed surgery to remove Tyler’s AVM.

“On the day of his surgery Tyler was acting very brave, but we were all scared,” said his wife, Briahnna. “We just didn’t know how it would all turn out. Tyler gave me his wedding ring to hold onto, to symbolize our bond.”

In AVM surgery, the surgeon first finds and disconnects the main arteries bringing blood to the AVM. Then, they carefully separate the core of the AVM known as the “nidus” from the surrounding brain. Finally, they disconnect the vein, allowing complete removal of the AVM.

Operating on an AVM is among the most difficult neurosurgical procedures. This is because of the challenges of discerning AVM feeding vessels from normal vessels in the same region, the need for delicate microsurgical dissection in separating the AVM nidus from the brain, and the potential for significant bleeding.

“Some neurosurgeons have likened AVM resection to ‘defusing a bomb,’ which is a somewhat dramatic metaphor,” said Dr. Graffeo, “but it admittedly captures the right vibe, in terms of it being a high-stakes and very technically complex procedure.”

Recovery

Dr. Graffeo successfully removed the AVM. After two weeks in rehab Tyler went home but Briahnna noticed that his personality had changed. He was having severe memory lapses which made it difficult for him to complete simple tasks.

“It was like his brain was rebooting,” said Briahnna. “It was like a computer because he went back all the way to high school. He was talking about friends that he had in high school, and he thought that he was still doing things with them.”

Dr. Graffeo explained that the combination of Tyler’s traumatic brain injury followed by the removal of a large, high-flow AVM involving the majority of his right frontal lobe likely impacted blood flow throughout his brain, causing these temporary symptoms.

Over the following year, Tyler continued to make a strong recovery. His memory has continued to improve, and he is back at work.

“Tyler is doing well but it’s really important to keep him on a schedule to help with his memory,” said Briahnna. “We are so grateful to Dr. Graffeo and the team who looked after him so well.”

Neurosurgical Multidisciplinary Team for Treatment of Complex Cases

OU Health is renowned for its multidisciplinary approach treating complex neurosurgical cases.

Dr. Graffeo emphasizes the team's world-class expertise, with multiple surgeons trained at leading institutions such as Mayo Clinic, Harvard, Cleveland Clinic, UCSF Health, and the Barrow Neurological Institute. This diverse and highly skilled team collaborates closely to provide personalized care for each patient, ensuring that every surgery is tailored to the individual's unique needs and treatment goals.

OU Health's approach to complex neurosurgical cases including AVM resection involves using the latest tools and techniques to safely treat these abnormal and potentially quite dangerous lesions, with the ultimate goal of minimizing risks from both the disease and the treatment. Dr. Graffeo and his colleagues offer the full suite of AVM treatments, including microsurgical resection, stereotactic radiosurgery, and endovascular embolization. Above all, their program is dedicated to individualized treatment plans that honor the values and goals of each patient, bringing exceptional neurosurgical care to the people of Oklahoma.

Learn more about our neurosurgery services and treatment, request an appointment or get a second opinion, or find out more about the neurosurgical team at OU Health by calling (405) 271-4912.