New studies cast doubt on the value of surgically installed ear tubes to relieve fluid buildup in children with middle-ear infections.

The surgery, which costs about $1,000, has surpassed tonsillectomy as the most common operation on U.S. children. But pediatricians are divided about the operation's safety."The adverse consequences may be significant compared to treatment with antibiotics," Dr. Michael Pichichero, of the University of Rochester, N.Y., said during the recent 28th Interscience Conference on Antimicrobial Agents and Chemotherapy.

He studied more than 100 children, about half of whom received six or more treatments with antibiotics and half of whom had received three or more sets of ear tubes for recurrent middle-ear infections.

Roughly 50 percent of the ear-tube group experienced some hearing loss - a worrisome consequence of middle-ear infections. Less than 5 percent of the antibiotic group showed hearing loss. Pichicherio doesn't yet know whether the hearing loss will be permanent. The ear-tube group also suffered eardrum damage far more often.

Doctors at Hadassah University Hospital in Jerusalem, Israel, treated 105 babies under age 1, using antibiotics, ear tubes or both. After 10 days, they found infection persisted in 63 percent of the babies who had surgery, 11 percent of the babies who received antibiotics and 13 percent of the babies who got both treatments.

However, there are cases in which there is no alternative to ear tubes, including those where children are allergic or unresponsive to antibiotics, or have had fluid in an ear for three or more months.