Every year, an estimated 4,000 cases of "retained surgical items," as they are known in the medical world, are reported in the United States. These are items left in the patient's body after surgery, and the vast majority are gauzelike sponges used to soak up blood. During a long operation, doctors may stuff dozens of them inside a patient to control bleeding.

The core of the problem, experts say, is that surgical teams rely on an old-fashioned method to avoid leaving sponges in patients. In most operating rooms, a nurse keeps a manual count of the sponges a surgeon uses. But in that busy and sometimes chaotic environment, miscounts occur, and a sponge can remain.

In recent years, new technology and sponge-counting methods have made it easier to remedy the problem. But many hospitals have resisted, despite the fact that groups like the Association of Operating Room Nurses and the American College of Surgeons have called on hospitals to update their practices. So patients are left at risk.

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