The duodenoscope is a very handy invention which allows physicians to see “inside” a patient’s digestive tract and makes it easier to diagnose pancreatic diseases and gall bladder issues. However, there is one major problem. They are virtually impossible to sterilize.

Because of this, thousands of patients have contracted serious bacterial diseases. Now, medical experts in the U.S. are calling upon the Food and Drug Administration to have them removed from the market and require medical device manufacturers to come up with designs that allow for full sterilization.

Estimates indicate that duodenoscopes are used to examine at least half a million patients yearly. These devices, which are essentially flexible fiber-optic tubes with a small camera at the end, enables doctors to diagnose and treat illnesses such as pancreatic cancer and gall bladder inflammation without having to resort to invasive surgery.

The problem is that a duodenoscope is a complicated device with a large number of components. Without thorough cleaning and disinfecting, it is possible for bacteria from one patient’s tissues or bodily fluids to be transferred to the next.

Herein lies the problem. Because of the delicate parts that make up the mechanism, a duodenoscope cannot undergo the normal sterilization procedures. Instead, the devices are washed by hand, then run through what is essentially a dishwasher as per manufacturer’s instructions. This fails to remove all bacteria.

Last April, the FDA required manufacturers to test their duodenoscopes after undergoing the recommended cleaning process. These tests revealed that at least 5% of all duodenoscopes were still infected with bacteria including e. coli even after they were cleaned – over ten times what was expected. Some types of bacteria that can be transmitted through a duodenoscope are resistant to antibiotics and can be nearly impossible to treat.

Numerous medical experts are now demanding that the FDA force manufacturers to recall existing products and come up with designs that can be properly sterilized. The advantages of the duodenoscope have turned out to be the very reason they cannot be fully sterilized. Most surgical instruments are placed in an autoclave, which uses high temperatures and steam pressure in order to completely kill off all microbes that may remain on their surfaces. However, because of their delicate mechanism and complex construction, a duodenoscope cannot be placed in an autoclave. Cleaning by hand or washing is a problem as well, because the instruments have many small “nooks and crannies” in which bacteria can survive.

Major duodenoscope manufacturers such as Olympus, Pentax, and Fuji claim that the devices are safe, provided the facilities are sterile and all cleaning instructions are followed. They also recommend that duodenoscopes be returned to the factory at least once a year for servicing.

Nonetheless, an investigation by the U.S. Senate Committee on Health, Education, Labor and Pensions has found dozens of cases of patients that have been sickened by contaminated duodenoscopes – even when these devices have been cleaned according to manufacturer guidelines. For example, 30 patients in Seattle hospitals who underwent duodenoscopy between 2012 and 2014 became seriously ill as a result of an antibiotic-resistant bacteria known as Carbapenem Resistant Enterobacteriaceae(CRE). More than one-third of the patients died.

The increase of antibiotic-resistant “superbugs” has made the issue all the more urgent. Although the FDA has been aware of the problem for the past 4 years, no serious action has been taken. In 2018, Pentax recalled a number of defective duodenoscopes after virulent bacteria was discovered in “clean” instruments that had been returned to the factory for servicing.

There are similar instruments, such as bronchoscopes, intended for single use only, that are becoming available. However, a single-use, disposable duodenoscope has yet to be approved. There is also a possibility that new, low-temperature sterilization methods using gas, ultraviolet light, and ozone could ultimately be used. In the meantime, patients who face duodenoscopy should be aware of the risks of serious infections from these medical devices.

K.J. McElrath is a former history and social studies teacher who has long maintained a keen interest in legal and social issues. In addition to writing for The Ring of Fire, he is the author of two published novels: Tamanous Cooley, a darkly comic environmental twist on Dante's Inferno, and The Missionary's Wife, a story of the conflict between human nature and fundamentalist religious dogma. When not engaged in journalistic or literary pursuits, K.J. works as an entertainer and film composer.