Merrill Kelly knew he was in trouble when his right arm doubled in size. This was late in the summer of 2020, when nothing about a routine checkup felt routine. Kelly, a right-handed starter, was trying to stick with the Arizona Diamondbacks after they signed him off the scrap heap in South Korea. If he could gut it out, ignore the swelling, look away from the discolored skin for just one minute, maybe the issues would go away.
That’s what he hoped, at least. Then he spoke with a former teammate who mentioned thoracic outlet syndrome.
“I had a blood clot that needed to be addressed immediately,” Kelly, 34, said in June. “I couldn’t lift my arm to shower. That’s how heavy it was.”
Since undergoing TOS surgery at the end of the 2020 season, Kelly made 27 starts in 2021 and 33 in 2022, and he is on pace for more than 30 this season. He has a 3.22 ERA in 95 innings for the Diamondbacks. He was in the all-star mix, though he’s on the 15-day injured list with a calf issue.
In Washington, where Stephen Strasburg remains away from the Nationals because of nerve issues — the same nerve issues he hoped TOS surgery would fix in the summer of 2021 — it’s common to ask whether a pitcher can look like himself after a procedure that removes a rib. And while Kelly has, only getting stronger in the years following surgery, not all TOS cases are the same.
Most of them, in fact, are quite different. Strasburg had neurogenic TOS, a condition caused by nerve compression that can lead to numbness and tingling from a pitcher’s shoulder to the fingertips. Kelly, on the other hand, had venous TOS (or vascular TOS), which typically addresses a blood clot. Once in a while, he will receive a message from a younger player who heard those scary words — thoracic outlet syndrome — and headed straight to Google.
But if the player is dealing with neurogenic TOS, the more common of the two among pitchers, Kelly can’t offer much assurance. He knows the key distinctions better than most.
“I heard a lot of horror stories about guys who had TOS, then TOS surgery, and never got back to who they were,” said Kelly, who had a rib and one neck muscle removed in his procedure. “If you had to pick, you’re not really sure which one you’d rather have [between venous and neurogenic TOS]. The blood clot was not fun. They are life-threatening. But for pitchers, TOS surgery to address a blood clot is much more straightforward than nerve issues. The diagnosis is more straightforward. The recovery is more straightforward. I was lucky in that way.”
So why, exactly, is it harder for pitchers to recover from neurogenic TOS?
“They get lumped together, but venous TOS is typically clinically more acute,” said Robert Thompson, founder of the Center for Thoracic Outlet Syndrome at Washington University in St. Louis. “It presents suddenly without any preexisting symptoms. These are players who are playing normally — no pain, numbness, tingling, no nerve-type symptoms. And they suddenly get arm swelling, and there ends up being a clot in the subclavian vein.
“Neurogenic TOS is kind of a contrast because those patients typically do have somewhat long-standing symptoms, involving at least numbness and tingling, and they may have overt pain or more of an ache or fatigue. They may describe dead arm when they are throwing, particularly pitchers. And to some degree, those symptoms may have been going on a long, long time, and they’ve made compensatory changes in their posture and mechanics that may ultimately be hard to reverse. So they kind of come with a little bit more baggage.”
Strasburg would be first in line to agree. After attempting to return last summer, he missed all of spring training and has rarely been at Nationals Park since. He has been shut down from baseball activities for more than two months. It’s becoming harder and harder to imagine him pitching again.
Those long-standing symptoms Thompson described — tingling, numbness, dead arm — led Strasburg to undergo carpal tunnel surgery in 2020, a procedure he believes was unnecessary and delayed his TOS operation. His recovery has been further complicated by past injuries and the wear on the right side of his body (which is why younger pitchers have a better chance at making a full recovery). In September, when Strasburg opened up about his nerve issues, he said he couldn’t stand for long without his whole right hand going numb.
“I can’t say exactly what the outcome is going to be — I really can’t,” Dave Martinez, the Nationals’ manager, said of Strasburg in early June. “But I know that it’s been frustrating for him, and it’s been an ongoing deal. So for me, I just wish Stephen the best no matter what happens moving forward. I just want him to get healthy.”
Thompson said about 80 percent of players who undergo surgery for neurogenic TOS return to competition. As for recovery, he predicts a year for the players who rebound, similar to the timeline for Tommy John surgery.
As expected, every projection is better for those who have surgery for venous TOS. Thompson estimated that 90 to 95 percent of players return to competition. Rehabbing can take less than two months. When Kelly picked up a ball again in 2020, he kept bracing for setbacks, knowing what other pitchers had gone through. But then he was cleared to throw at full strength after just six weeks.
“That blood clot put me in a really, really dark place for a bit,” Kelly said. “But the clot was gone, the rib was gone, and there wasn’t much for me to heal. I remember thinking: ‘This is going to be a grind. This could be bleak.’ And then I get to week four and it was like, ‘So when is this supposed to get hard?’ ”