BANGALORE -- Hair tucked into a surgical cap, eyes hidden behind thick-framed magnifying glasses, Devi Shetty leans over the sawed open chest of an 11-year-old boy, using bright blue thread to sew an artificial aorta onto his stopped heart.

As Dr. Shetty pulls the thread tight with scissors, an assistant reads aloud a proposed agreement for him to build a new hospital in the Cayman Islands that would primarily serve Americans in search of lower-cost medical care. The agreement is inked a few days later, pending approval of the Cayman parliament.

Dr. Shetty, who entered the limelight in the early 1990s as Mother Teresa's cardiac surgeon, offers cutting-edge medical care in India at a fraction of what it costs elsewhere in the world. His flagship heart hospital charges $2,000, on average, for open-heart surgery, compared with hospitals in the U.S. that are paid between $20,000 and $100,000, depending on the complexity of the surgery.

The approach has transformed health care in India through a simple premise that works in other industries: economies of scale. By driving huge volumes, even of procedures as sophisticated, delicate and dangerous as heart surgery, Dr. Shetty has managed to drive down the cost of health care in his nation of one billion.

His model offers insights for countries worldwide that are struggling with soaring medical costs, including the U.S. as it debates major health-care overhaul.