“When I first got drafted, that was the biggest achievement in my entire life,” said Koloko, who stands at 6 feet, 11 inches. “Every kid’s dream is to hear their name called, so it was a big moment for me and my family.”

Koloko started his career in Toronto, but his excitement was short-lived.

“During my rookie season, I started experiencing some shortness of breath and I was getting tired much more quickly than usual,” Koloko said. “I went to see my doctors with the team because I just felt like something was wrong.”

Testing found a blood clot in Koloko’s lungs. With no indication of where the clot was coming from, Koloko was placed on blood thinners, which sidelined him for most of the following season because the medication could cause severe internal bleeding if he was injured on the court. His team released him from his contract, and he was placed on the NBA's fitness-to-play panel—meaning no team could sign him until he was medically cleared.

“I went to see so many different doctors, but the response was always the same,” Koloko said. “They couldn’t find the source of the clot, so I was just going to have to be on blood thinners the rest of my life and I wouldn’t be able to play basketball anymore. After just one season, I thought my career was over.”

But Koloko and his family pressed on for answers, turning to Cedars-Sinai for another opinion. That’s where he met Ali Azizzadeh, MD, director of the Division of Vascular Surgery at Cedars-Sinai and associate director of the Smidt Heart Institute.

“When we examined Christian, we found that his left arm was three centimeters bigger in diameter than his right, which suggested a narrowing of the vein,” Azizzadeh said. “We performed a venogram that revealed a major clot in the vein draining his left arm, allowing us to diagnose venous thoracic outlet syndrome.”

Thoracic outlet syndrome (TOS) is a condition caused by pressure on blood vessels or nerves in the space known as the thoracic outlet between the neck and the shoulder. Koloko was experiencing a rarer type of TOS—known as venous TOS—in which the subclavian vein is pinched between the collarbone and first rib, causing damage and narrowing the vein.

“In Christian’s case, chronic overhead trauma likely led to scarring in the vein draining his arm. This scarring narrowed the vein and allowed clots to form,” Azizzadeh said. “We tend to see this in athletes—including basketball players, baseball players and swimmers—due to the repetitive overhead movements in their sports.”

To fix the issue, Azizzadeh and his team at Cedars-Sinai surgically removed Koloko’s first rib and some of the muscles that are connected to it to make more room for the vein. They also removed scar tissue from around the vein, placing a patch to make the vein bigger and allowing blood to flow freely. This meant Koloko could stop taking the blood thinners that were keeping him from the game—and job—he loved.

Just a few months after surgery and rehabilitation, Koloko was cleared to play by the NBA and back to his regular workouts on the court. He will kick off the 2026-27 NBA season this fall playing for the New Orleans Pelicans. With preseason just around the corner, Koloko is glad to have his health issues behind him.

“I’m just grateful for everything,” Koloko said. “Getting back to playing basketball, I’m grateful to Dr. Azizzadeh, my family and everyone who supported me during that process.”

When the season starts, Azizzadeh will be rooting for him.

“I’m glad to see Christian back on the court, and I’m looking forward to watching him play this season,” Azizzadeh said. “This is his second chance to be a true NBA star, and we’re delighted to have played a role in helping him get there.”

Read more from Cedars-Sinai Stories and Insights: Understanding Vascular Malformations

In an essay published in Variety, Malkin revealed that soon after covering the 2025 Academy Awards, he underwent surgery at Cedars-Sinai for an aortic aneurysm. Malkin, 55, is now back on the red carpet, feeling stronger by the day and advocating for preventive heart health to anyone who asks.

Malkin wants to observe Aortic Disease Awareness Month in September by sharing his story far and wide to encourage people with high risk factors—family history, smoking or muscle disease—to consider seeing a physician for screening.

“I've always said if I can help one person, that makes it worth it,” Malkin said.

An aortic aneurysm is a bulge in the large artery that runs through the center of the body. Aortic aneurysms are often found incidentally, as Malkin’s was. If an aneurysm grows to a certain size, it can tear or rupture—resulting in internal bleeding and even death.

“Marc’s case is an example of how you can be young and healthy and have an aneurysm,” said Dominick Megna, MD, surgical co-director of the Cardiac Surgery Intensive Care Unit and a cardiothoracic surgeon in the Smidt Heart Institute at Cedars-Sinai.

Aneurysms are especially dangerous because they don’t usually cause symptoms.

“Aneurysms can be asymptomatic and undiagnosed until rupture, which is why they’re often referred to as a  ‘silent killer’ or ‘time bomb,’” said Ali Azizzadeh, MD, director of the Division of Vascular Surgery at Cedars-Sinai. “We encourage all patients with risk factors or family history to get screened.”

Malkin had originally made an appointment with cardiologist Erika Jones, MD, to manage his high cholesterol and track his heart health. When Jones discovered an aortic root aneurysm in Malkin’s chest, it caught everyone by surprise.

 “I was really scared,” Malkin said. “But both my cardiologist and surgeon said ‘knowledge is power.

Malkin enrolled in the Aortic Surveillance Clinic in the Smidt Heart Institute and began meeting with surgeons, nurses and cardiologists. He underwent routine imaging and screening to measure the size of his aneurysm, which was growing to the point of requiring surgery.

“When an aneurysm grows to 5.5 centimeters in men or 5 centimeters in women, patients are usually referred for surgery,” Megna said. “Some people choose to get surgery sooner to end their worry. Each patient and their care team can make treatment choices specific to their emotional and physical needs.” 

Malkin, the senior culture and events editor at Variety, was worried the surgery might put an end to the work he loves. 

“I cried,” Malkin said. “And I’ve admitted this before: I asked my surgeon if we could wait until after the Oscars.”

Malkin underwent surgery about a week after the 2025 Academy Awards and today is focused on keeping himself healthy. He works out three times a week at the cardiac rehab center at Cedars-Sinai, where nurses and physical therapists monitor his heart activity. He encourages everyone he meets—celebrities and neighbors alike—to see a cardiologist if they have a family history of heart disease or any cardiac risk factors. 

“I tell patients they won’t feel totally differently physically, but mentally they’ll know they’ve corrected something to prevent future catastrophe,” Megna said.

Read more from Discoveries Magazine: A Pioneering Heart Procedure