Complications of Robotic Surgery Underreported, Study Says

September 05, 2013

More injuries and deaths are linked to da Vinci robotic surgery than meet the eye, according to a new study published online August 27 in the Journal for Healthcare Quality.

As a result, "we're not learning from our performance," study coauthor Martin Makary, MD, MPH, told Medscape Medical News.

Between January 1, 2000, and August 1, 2012, the US Food and Drug Administration (FDA) received 245 adverse event (AE) reports related to the controversial da Vinci robotic surgical system, made by Intuitive Surgical. Scouring federal court records and media accounts, Dr. Makary and colleagues found 5 more cases that were never reported. They also discovered that 3 reported cases were problematic. One was submitted 930 days after the surgery, and another 292 days after. The latter case, as well as a third dubious one, was submitted to the FDA only after a media report of the patient's death appeared.

Dr. Makary said the 8 cases uncovered by his study, including the 5 never submitted to the FDA, make up a "sampling" of a large but unknown number of unreported or misreported AEs associated with da Vinci surgery.

"We think that based on the sample, the 245 reported cases represent a small fraction of the true events out there," said Dr. Makary, an associate professor of surgery at the Johns Hopkins University School of Medicine in Baltimore, Maryland. The number of reported cases, he added, "seems very low, given the discussion of these events in the surgical community."

Intuitive Surgical did not respond to a request for comments by Medscape Medical News as of press time. In its filings with the US Securities and Exchange Commission (SEC), the company maintains that its da Vinci technology continues to be "safe and effective," as demonstrated by a growing body of scientific evidence.

Lawsuits, Regulatory Scrutiny, and Professional Skepticism

The study in the Journal for Healthcare Quality is just the latest whiplash for da Vinci robotic surgery, which faces a gauntlet of litigation, regulatory scrutiny, and professional skepticism about its safety and cost-effectiveness. The computerized technology allows a surgeon to manipulate laparoscopic instruments attached to robotic arms while viewing the procedure in 3 dimensions, just as if it were open surgery. First approved by the FDA in 2000, the da Vinci Surgical System was used to perform some 367,000 procedures in the United States last year, up from 292,000 in 2011, according to Intuitive Surgical. Roughly 8 in 10 procedures were gynecologic or urologic, with hysterectomies and prostatectomies leading the way. As of June 30, there were some 2000 da Vinci systems installed in US healthcare facilities.

With snowballing adoption of the technology has come controversy. Earlier this year, the FDA began surveying physicians using the da Vinci system about its strengths and weaknesses after the agency spotted a 34% spike in AE reports filed with the FDA's Manufacturer and User Facility Experience (MAUDE) database from 2011 to 2012. The number of da Vinci procedures during that period increased 26%.

An FDA spokesperson told Medscape Medical News that the agency is still reviewing the results of the survey.

A study published in February in JAMA reports that robot-assisted hysterectomy posted complication rates similar to those for laparoscopic hysterectomy but cost almost $2200 more per operation. The next month, the American College of Obstetricians and Gynecologists declared that robotic surgery "is not the only or the best minimally invasive approach for hysterectomy," nor is it "the most cost-efficient."

In May, the FDA issued an inspection report of the manufacturer's headquarters in Sunnyvale, California, that faulted the company for failing to disclose measures it took to guard patients from accidental electrical burns, which have been a recurring problem.

In a report filed with the SEC for the second quarter of 2013, the company said it is a defendant in roughly 30 product liability lawsuits and that plaintiffs' attorneys are spending big bucks to solicit more clients with injury claims. In May, a Washington state jury found that Intuitive Surgical was not liable for the death of a man who underwent da Vinci–style prostate surgery. Lawyers for the man's estate failed to convince the jury the company had not properly trained the surgeon on the equipment.

Device-Related Problems May Go Unreported as User Errors

Dr. Makary and colleagues point to several possible reasons for underreporting da Vinci complications. One reason is that injuries sometimes appear to result from user error, when in fact they reflect an issue with the device.

"Many surgeons believe it's easier to make errors with robotic surgery given the lack of haptic feedback," Dr. Makary told Medscape Medical News. Unable to feel how firm a blood vessel is, a surgeon may accidentally sever it, for example.

Another explanation for lowball AE figures is the MAUDE reporting system, which the authors said is neither standardized nor timely. One problem in particular is its reliance on self-reported cases. Dr. Makary said he favors a system used by the American College of Surgeons, which relies on independent nurses to identify and monitor AEs.

The 5 unreported AEs uncovered by the study in the Journal for Healthcare Quality strike one observer as "a pretty small number."

"It's a 2% error rate," said Steven Schwaitzberg, MD, an associate professor of surgery at Harvard Medical School in Boston, Massachusetts, and an editorial advisory board member and contributor to Medscape General Surgery. "It's not bad."

At the same time, Dr. Schwaitzberg said, mishaps with medical devices in general tend to be underreported. He attributes that trend not to the sinister intentions of manufacturers but to "a lack of understanding among clinicians about their reporting obligations."

He also agrees with Dr. Makary that the healthcare system needs a more robust system for tracking AEs.

"Until we build a better system, underreporting will be a problem with every medical device," he said.

The authors have disclosed no relevant financial relationships.

J Healthcare Quality. Published online August 27, 2013. Abstract


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