A year ago we wrote about bronchial thermoplasty, a new asthma treatment that works by searing off part of the airway muscles which enlarge and restrict breathing during an asthma attack. A device was developed to do this, Alair, and then purchased by Boston Scientific for $193,500,000. Executives estimated it would become a billion dollar industry by 2020.

But few people are getting the procedure.

Why? It mostly has to do with health insurance. The procedure costs $20,000 and many of the largest insurers, including Cigna Corp. and Anthem Inc., won’t pay for it. According to Anthem spokesperson Jill Becher, “Bronchial thermoplasty is considered investigational and not medically necessary for the treatment of asthma. This procedure has real and significant complications and the ongoing concern is the relative safety as compared to the benefit.”

It’s hard to say whether insurance companies are genuinely concerned about the safety of the procedure, which has a lot of medical backing, or if they simply want to avoid paying the bill. Either way, the procedure can have negative side effects including congestion, bronchospasm, and worsening airway hyperreactivity. But it also has some amazing benefits, including reducing asthma attacks by 44% and reducing emergency room visits by 78% (at least according to a company-funded study).

Christi Thompson, a home ec teacher from Ohio, had the procedure two years ago. Initially, she reacted poorly and had to spend two days recovering in the hospital (most patients go home the same day). Even so, the procedure was worth it for her. She now has severe asthma symptoms far less frequently. “I don’t have to use my nebulizer as many times a day as I did prior to the surgery, and I don’t feel I’ve had to take as many bouts of steroids,” Thompson said.