Are there any US based forms of health insurance that allow medical tourism

I was reading this

http://www.atimes.com/atimes/South_Asia/FH31Df04.html

The CII study estimated that “heart surgery in the US costs $30,000, while it costs $6,000 in India. Bone marrow transplants cost $250,000, while they are $26,000 in India.” Figures vary, but a general rule of thumb puts the difference in costs of services in the West at one-fifth to one-tenth. It is this disparity on which India is trying to capitalize.

And it made me think. Aren’t there any US based insurance companies that offer insurance for medical tourism instead of a domestic indemnity, PPO or HMO plan? It would seem like a good way to insure those with major health problems.