Analysis Backs FDA Duodenoscope Cleaning Advice

Christopher Almario, MD, MSHPM

New cleaning guidelines recommended by the U.S. Food and Drug Administration (FDA) for duodenoscopes offer the most cost-effective strategy for reducing the transmission risk of the bacteria CRE, or carbapenem-resistant enterobacteriaceae, according to a new Cedars-Sinai study.

Duodenoscopes — flexible, lighted tubes that are threaded through the mouth, throat and stomach into the small intestine — are used in more than 500,000 procedures each year in the US, according to the FDA. Those procedures, known as endoscopic retrograde cholangiopancreatography (ERCP), are performed for patients with symptomatic common bile duct stones and related conditions. The FDA has identified evidence that duodenoscopes have contributed to the transmission of infections, including antibiotic-resistant infections such as CRE, to patients.

The health economic analysis, from the Cedars-Sinai Center for Outcomes Research and Education, evaluated four strategies for reducing the risk of CRE transmission in ERCP. The researchers compared the new FDA cleaning guidelines with three other approaches: sampling after ERCP for bacterial growth and keeping the devices out of service for 48 hours until cultures are negative; using ethylene oxide gas to sterilize the equipment; and halting the use of ERCP in favor of surgical and interventional radiology procedures.

The Cedars-Sinai study confirmed that the FDA instructions describe the most cost-effective method to lower transmission risk in patients with bile duct stones who undergo ERCP. The analysis was published online Nov. 3 in the American Journal of Gastroenterology.

The FDA issued its new guidelines in March after several hospitals, including Cedars-Sinai, reported CRE infections in patients who underwent ERCPs. Cedars-Sinai infection-control specialists announced the same month that they had identified four patients with CRE transmission linked to ERCP. The same duodenoscope was used in all four patients, who underwent procedures from August 2014 to January 2015.

The duodenoscope used with the patients has a recessed elevator channel that allows for the placement of guide wires, catheters and other features. The FDA's new instructions called for additional brushing of the recessed channel with a smaller cleaning brush, as well as additional flushing of the device's shaft.

Cedars-Sinai has meticulously followed the FDA's disinfection procedures. It also has gone above and beyond the manufacturer's recommendations since learning in February that the company's guidance might not be sufficient to protect patients.

"We view CRE as a risk that every hospital faces, and we hope our research serves to advance the science and health economic discussion around a problem that hospitals must solve," said Christopher Almario, MD, MSHPM, a Cedars-Sinai health services researcher and the first author on the study.

In evaluating the three alternatives to the FDA guidelines, the researchers determined that the "culture and hold" strategy was most cost effective in institutions with a high CRE prevalence. They also determined that the use of ethylene oxide was not cost-effective under most circumstances, even though it is believed to offer the best chance of sterilizing duodenoscopes. In addition, they found that the surgical alternative is unlikely to replace ECRP as the preferred method to manage symptomatic common bile duct stones in settings where the prevalence of CRE is low.

Several Cedars-Sinai physicians and research scientists were involved in the analysis. The team included Kapil Gupta, MD, MPH, MBA; Laith H. Jamil, MD, associate director of the Cedars-Sinai Endoscopy Service; Simon K. Lo, MD, director of the Interventional Endoscopy Service; Rekha Murthy, MD, medical director of the Hospital Epidemiology Department and professor of Medicine; and Brennan Spiegel, MD, MSHS, director of the Cedars-Sinai Center for Outcomes Research and Education and professor of Medicine.

Ultimately, the researchers said they hope their work will serve as a resource as hospitals evaluate procedures for keeping patients safe.

"We view this research as an example of how Cedars-Sinai can learn from a difficult situation and advance the science for others," Spiegel said.

Citation: American Journal of Gastroenterology: 2015 November: Cost Utility of Competing Strategies to Prevent Endoscopic Transmission of Carbapenem-Resistant Enterobacteriaceae