Specialized surgery for brain aneurysm at UTHealth Houston has patient flying aerobatics again

Mijali Munoz Proestakis, 56, is a self-admitted bit of a daredevil who loves aerobatic flying, jet surfing, mountain biking, and free diving, among other adventure sports. But he wasn’t taking any chances after he suffered a stroke out of the blue a year ago.

Proestakis, an engineer who directed the drilling operation that bore down 2,300 feet to rescue 33 trapped Chilean miners in 2010, used that same methodical mindset to get to the bottom of what caused his stroke and find a UTHealth Houston team that would make sure it wouldn’t happen again.

The Chilean businessman, whose drilling supply company does work both in Chile and the U.S., woke up in Santiago, Chile, on July 10, 2024, with what he described as a “huge pain” in the back of his neck. It had been a particularly stressful week, he said, that included the death of a beloved executive assistant who was just 31 when she coincidentally died of a stroke.

Proestakis tried and failed to get out of bed three times that morning and couldn’t move his left arm. He couldn’t even sit up, as he experienced a complete loss of balance. He rushed to the nearest emergency room for an MRI and was diagnosed with an ischemic stroke, but it was too late to administer the typical clot-busting medicine. By the next day, he had recovered enough to be able to walk, but he was grounded from flying.

Physicians at the Santiago clinic also looked for a patent foramen ovale, or PFO, which is a hole between two chambers of the heart that can let a blood clot escape and travel to the brain, causing a stroke. They discovered he had one and recommended closure, a simple surgery that he underwent by the end of that month.

He travelled back to Houston feeling better but was still suffering some pain at the back of his neck. He had a strong feeling to get a second opinion. A Chilean doctor he knew at The University of Texas MD Anderson Cancer Center recommended UTHealth Houston neurology.

In October 2024, Proestakis saw three physicians, all assistant professors, from the Department of Neurology at McGovern Medical School at UTHealth Houston: vascular neurologist Chigozirim Izeogu, MD, MPH; sports neurologist David Babbit, MD; and endovascular neurologist Michael I. Nahhas, MD.

An MRI at UTHealth Houston, ordered by Izeogu, revealed the issue: a fusiform aneurysm, which is a bulge that is shaped like a sausage and involves the entire wall of the artery. In Proestakis’ case, the aneurysm, which could dissect or rupture, was located on one of the posterior inferior cerebellar arteries (PICA) [LDM1] at the base of the brain. The shape of the aneurysm meant that it could not be corrected with a clip to section off the bulge. Furthermore, Nahhas did not think that endovascular treatment with a stent was doable or safe, in view of the location and configuration of the aneurysm.

Proestakis was referred to Jacques J. Morcos, MD, professor and chair of the Vivian L. Smith Department of Neurosurgery and a John P. and Kathrine G. McGovern Distinguished Chair at McGovern Medical School. Morcos, who is also co-director of UTHealth Houston Neurosciences, specializes in cerebrovascular and skull base neurosurgery, including arterial brain bypass surgery.

The PICA is one of the most challenging arteries for surgery because of its twisting nature. It supplies blood to the cerebellum and brain stem, and an aneurysm can lead to a brain hemorrhage or a stroke, which is what happened to Proestakis.

“If we had not treated it, the aneurysm could have ruptured into a full-blown subarachnoid hemorrhage, or it could have kept ballooning, showering off emboli and causing a stroke in the cerebellum. That is what he had on the first event,” Morcos said. “The alternative to surgery could have been to try and place a stent, but the location of the aneurysm ruled this out, as it would have either failed or caused closure of the artery and a stroke.”

Proestakis told Morcos that he felt like a ticking time bomb. “You are,” Morcos replied to him.

Of the 10,000 brain surgeries Morcos has done in his career, more than 500 have been bypasses. His approach to Proestakis’ surgery would be to create a bypass from the normal PICA artery to the other side, which runs parallel. This is called a PICA-PICA side-to-side bypass, done in addition to trapping, or isolating, the aneurysm.

“Those two arteries come close to each other in the posterior part of the brain. I connect them together with very small sutures. The thread is so small, you would have to bundle 50 of them to reach the size of a human hair. After creating the connection left-right, I can trap off the aneurysm and cure it. The blood flow is taken over from the other side,” Morcos said. “Of all the aneurysm surgeries we do, only 1% are done in this way.”

Proestakis did his homework, looking up Morcos and his extensive background as a cerebrovascular specialist. He was also impressed that Morcos was familiar with g-forces, which aerobatic pilots experience. He let Morcos know that it was important for him to be able to keep flying. The decision was an easy one to make, Proestakis said. He met with Morcos on a Monday, and the surgery was scheduled for that Thursday.

“As an engineer, what he was telling me made sense,” Proestakis said. “It was amazing watching the process and how professional they were. I had an angiogram right before surgery and another one right after surgery to make sure there were no leaks. You could see the team work and the energy flow. I told both my daughters to not worry – I would be at their weddings because I was with the best guy in the world.”

Proestakis woke up from his Nov. 14, 2024, surgery seeing double, but that resolved within half an hour. The next day, he was up walking. He was released four days later. In six weeks, he felt back to normal.

“He did super well,” Morcos said. “His balance is perfect, and that is key because the aneurysm was in the area of the cerebellum that has to do with balance. He is able to do the sports he enjoys. Most importantly, he is completely cured from his aneurysm and has returned to all activities.”

Six months after surgery, Proestakis was cleared to fly with a second pilot on board, and he was just recently cleared to fly solo again.

“I was, and am, supported by a great medical team, and I was really lucky to find them,” Proestakis said. “I want to thank them for letting me get back to life and flying with the same lifestyle I had before the stroke.”

Early in his journey to get to the root of his stroke, he made a promise to himself that he would fly in an air show in Chile with a new plane in 2026.

He’s already bought the plane.

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