The safety of an increasingly popular surgical robot is yet again being called into question, with new research revealing that some mishaps associated with the system are going unreported.

Called the da Vinci system and made by Intuitive Surgical Inc., the multi-armed robot has been introduced in more than a quarter of US hospitals since first being approved by the Food and Drug Administration (FDA) in 2000. Since then, however, the robot has been implicated in one controversy after another. And now, a study out of Johns Hopkins University suggests that mishaps during da Vinci procedures are "vastly underreported" to the FDA: a total of 247 injuries or deaths have been filed with the agency since 2000, but researchers uncovered another five such incidents that never made it onto the FDA's radar. They also concluded that three reports weren't submitted in a timely manner — with one incident being filed with the FDA nearly three years following the surgery.

"We have this haphazard smattering of reports."

An additional five mishaps might sound insignificant, but some suggest that the finding still underestimates the number of da Vinci incidents that have gone unmentioned: reports filed with the FDA are merely "the tip of the iceberg" where surgical complications are concerned, according to Diana Zuckerman with the National Research Center for Women and Families. And without accurate data on how often robotic surgeries are going wrong — and why — improving their safety will remain a challenge. "In health care ... we have this haphazard smattering of reports that relies on voluntary self-reporting with no oversight, no enforcement and no consequences," study co-author Martin Makary, MD, told the New York Times.

Representatives for Intuitive Surgical say that any perceived uptick in errors can be attributed to more surgeries: da Vinci robots performed around 100,000 procedures in 2008, compared to 367,000 last year. And adverse incidents, a company spokesperson notes, are diligently reported to the FDA. "We take this requirement very seriously and make every effort to account for all reportable events — even those from several years prior."

Some surgeons have lauded the system

The da Vinci, which is often used for prostate removal surgeries and hysterectomies, is by no means autonomous. Instead, the robot is operated by a surgeon using hand controls and monitoring the surgical procedure from a computer screen. Some surgeons have lauded the system for its efficacy in performing delicate procedures in hard-to-reach places, and have also noted that da Vinci offers unparalleled consistency and precision. But detractors argue that the robot, which has spurred several lawsuits, is no better than traditional laparoscopic surgery — and might even be more dangerous, either because surgeons aren't properly trained to use it or because of unexpected system malfunctions.

As robotic surgeries become more popular, some researchers are trying to ensure that such malfunctions don't occur. Teams at Carnegie Mellon and Johns Hopkins are working to improve the identification of bugs and defects in robotic hardware and software.