These Devices Sickened Hundreds. The New Models Have Risks, Too.

After medical instruments called duodenoscopes sickened hundreds of patients in hospital outbreaks a few years ago, the Food and Drug Administration urged health care facilities to switch to models with disposable components less likely to carry bacteria from one patient to another.

Now the agency says there are problems with those instruments, too.

Duodenoscopes are long, snakelike cameras inserted into the upper part of the small intestine through the mouth to diagnose and treat diseases of the pancreas and the bile duct. They are used in about 500,000 procedures a year in the United States, but are difficult to clean completely and can harbor disease-causing microbes like E. coli.

Olympus Medical Systems produces duodenoscopes with disposable tip covers shaped like tiny thimbles that cover the camera at the far end of the instrument.

But in scores of procedures, the tips have fallen off in patients’ mouths or stomachs, according to reports filed with the F.D.A. Some of these bits had sharp edges that cut patients, leading to internal bleeding.

In a case report dated May 20, 2021, a physician was removing a scope from a patient’s stomach “when the soft tip cover of the scope fell off into the patient’s stomach.”

“It was decided to allow the tip cover to pass naturally through the GI system than to subject the patient to further anesthesia time in attempting to remove it,” the report said.

The F.D.A. sent an inspector to the Olympus Medical Systems facility in Tokyo late last year. Agency officials warned the company this month that the inspector had found that disposable parts made for two scopes — covers for duodenoscopes and suction valves for bronchoscopes, used to examine the lungs — were adulterated or defective.

The agency said that it had received about 160 complaints about caps falling off duodenoscopes, and noted that Olympus’s own analysis had determined that the tally “was above the expected numbers for that type of complaint.”

The warning was not the F.D.A.’s first communication with the company, and the responses so far were “not adequate,” the agency said: “The F.D.A. does not agree that the risk to the patient is of a low enough risk to not warrant further action at this time.”

A spokeswoman for Olympus, Jennifer Bannan, said that while the company had already taken a number of measures to address the deficiencies, it “will further evaluate these actions” and “expand those efforts” in order to ensure that Olympus fully addresses the problems identified by the F.D.A.

“Olympus takes this Warning Letter very seriously,” Ms. Bannan said in an emailed statement. “The company is working diligently to address the issues raised in the letter in a timely manner.”

Other companies manufacture scopes with disposable components, and some are already making fully disposable duodenoscopes, which the F.D.A. first cleared in 2019. At the moment, it is not clear whether hospitals and patients should opt for those alternatives.

In January, Dr. Jeff Shuren, director of the F.D.A.’s Center for Devices and Radiological Health, issued a statement describing the problems at Olympus, but noted that the risk of infection from inadequate cleaning of duodenoscopes was relatively low.

The center did not recommend canceling or postponing procedures “without discussion of the benefits and risks” with patients, he said.

But the latest warning letter to Olympus noted other deficiencies, including wrinkles and air bubbles in the sealed packaging of single-use suction valves for bronchoscopes. The irregularities raised questions about the sterility of the valves, the F.D.A. said.

The agency also expressed concern about reports of cracked duodenoscope caps that malfunctioned during use, causing injuries.

Some of the reports filed with the F.D.A. described lacerations that caused bleeding episodes with serious consequences. In one case, a doctor noticed the patient was bleeding from the mouth after inserting the scope.

The doctor withdrew the scope, stopped the procedure and transferred the patient to another hospital, where a blood transfusion was administered. The patient experienced painful swallowing for several days afterward.

When the doctor repeated the procedure later on the same patient with an older scope lacking the disposable component, the doctor discovered a 13-centimeter-long laceration in the esophagus that was in the process of healing.