Flaws in adverse event reporting kept power morcellators in use

In 2015, the Government Accountability Office announced an investigation into power morcellators, bladed, drill-shaped devices used to remove uterine fibroids in minimally invasive procedures. Now, the results are in—and they’re not good.

The FDA’s passive adverse event reporting system depends on individuals to flag problems associated with medical devices. In the case of power morcellators, the GAO found, doctors and hospitals did not tell the FDA about the risk of spreading cancer via power morcellation.

The GAO reported that the FDA has known since it approved the first power morcellator in 1991 that the devices could potentially spread tissue, cancerous and noncancerous, around the body. Based on information available at the time, the agency believed the risk of spreading undetected cancers to be low, the GAO reported. The risk was thought to be between 1 in 500 and 1 in 10,000, according to The New York Times.

In 2014, the FDA upped its estimate, saying the risk of cancer spread was much higher—one in 350—and issued a new safety guidance, advising against the use of the devices in the “majority” of women undergoing a hysterectomy or uterine fibroid removal.

But why did it take the FDA 25 years to take action?

In 2013, the agency received its first adverse event report about a patient whose undiagnosed cancer had spread after undergoing a hysterectomy. By September 2016, the FDA had received 285 adverse event reports about the spread of cancer.

As more reports flooded in, a Columbia University study involving more than 36,000 women treated with morcellators at 500 U.S. hospitals found that one in 370 women who had undergone a hysterectomy also had a hidden uterine cancer.

“The passive reporting of adverse events is a weak system,” Marcia Crosse, director for healthcare at the GAO, told The New York Times.

In the case of power morcellators, some healthcare providers told the GAO they would not have interpreted the spread of an undetected cancer as an adverse event. They understood “adverse event” to relate strictly to the device’s function, that is, cutting up and removing tissue. So the problem went unreported.

To address the limitations of its adverse event reporting system, the FDA announced in 2016 that it would work with hospitals to develop a system that "quickly identifies life-threatening problems caused by medical devices." It also pledged to keep evaluating new devices, such as morcellation containment systems, which aim to reduce the likelihood that tissue is distributed around the body during a morcellation procedure.