Treating Atrial Fibrillation: Over 1 Million Cryoballoon Ablation Procedures

March 29, 2022

Soon to be a cardiologist, Paul Wang, now Professor of Medicine at Stanford, had an idea to make the treatment of heart rhythm problems simpler and safer.   That was 1985; now in 2022, 1 million patients will have been treated by this innovation.

Wang took an early interest in cardiology and in particular heart rhythm problems, many of which required open heart surgery to treat.  He went to watch open heart surgery by a pioneering heart surgeon.  Wang noticed that the surgeon used a metal instrument that was able to freeze the part of the heart that was responsible for creating the heart rhythm problem.   He reasoned that if this was the favored method by a surgeon perhaps a method that he did not require open heart surgery could be developed.

The search began- how could a system be developed to treat patients in such a novel way?  About 10 years earlier the first recording the electrical signal of the heart had been made using a small plastic tube called a catheter inserted from a leg or arm vein.  Wang reasoned that maybe a catheter could be developed to freeze the heart to treat heart rhythm problems.  But the heart surgeon’s tool was about the size of one’s thumb, much wider than could be inserted through a vein to the heart.  It was also a long distance to go from the vein to the heart.

Cardiac Cryoablation Catheter

Wang, about to start his training in cardiology, went to his mentor Peter Friedman, an expert in heart rhythm problems, and together they started to invent the catheter that would be called a cryoablation catheter. Cryoablation was the process of freezing tissue and had been used to treat a large range of medical problems using the same system used by the heart surgeon.  A cryoablation catheter would be entirely new invention – needing to prevent freezing along the course of the catheter in the body and yet

able to achieve temperatures of -60 to -70 degrees C, far below the temperature to freeze water or even antifreeze fluid.

Wang and Friedman went to a professor at MIT.  They made the first designs of the cryoablation catheter that they would ultimately patent.  

No company had the expertise to create catheters and perform cryoablation so a separate company, CryoCath, was created.  The first catheters were straight tubes and used to treat heart rhythm problems that are localized in small regions of the heart.   The first patient treated was by Marc Dubuc in Montreal, Canada.  It would be several years later that cryoablation catheters were developed to treat atrial fibrillation, the most common heart rhythm problem, occurring in 30 million patients worldwide. Finally, nearly 10 years later the cryoablation balloon catheter was developed and FDA approved.  Wang reported the first experiment on cryoablation balloon and has co-authored papers on the best practices using the cryoablation balloon.  

There have now been over 1 million cryoballoon ablation procedures performed globally.  

Dr. Paul Wang