Mon Apr 18, 2005 4:07 PM ET

CHICAGO (Reuters) - The risks of stomach-stapling surgery can be minimized if it is performed in a hospital that specializes in the difficult weight-loss procedures, a report said on Monday.

Doctors at Tufts-New England Medical Center in Boston said they reached that conclusion after reviewing the records for 750 surgeries on morbidly obese patients who underwent surgery there between 1998 and 2004.

They found that for the first 100 surgeries there were complications in 26 percent of the cases and a 1 percent death rate.

But as more procedures were done, the overall complication rate fell to 15 percent and the death rate to .03 percent. The surgeons were also able to do the procedure in less time as they gained experience.

The operation studied was Roux-en-Y gastric laparoscopic bypass surgery, in which the stomach is reduced by stapling or banding off part of it and connecting the remaining stomach to the middle part of the small intestine.

"Many bariatric surgeons believe that the degree of difficulty of the procedure and the unique high-risk nature of the patient ... mandates limiting this field to centers that specialize in it and perform it on a regular basis," said the study.

"There is no dispute that the complications associated with the (the surgery) were dramatically reduced after approximately 100 cases were performed," said the report, published in the Archives of Surgery. The finding has also been supported by earlier studies.

The number of such procedures in the United States has increased by 644 percent in the last decade, the study said, but it remains a technically different operation that is performed on patients who are already at risk given their weight.

More than 140,000 gastric bypass operations were performed last year in the United States, up from 103,000 a year earlier, according to the American Society for Bariatric Surgery.

The Roux-en-Y procedure was the most common. Complications can include intestinal leaks, pulmonary embolism, blood clots or, in 0.5 percent to 1 percent of patients, death, according to the Massachusetts Public Health Department.