The use of robotic surgical systems is expanding rapidly, but hospitals, patients and regulators may not be getting enough information to determine whether the high tech approach is worth its cost.

Problems resulting from surgery using robotic equipment—including deaths—have been reported late, inaccurately or not at all to the Food and Drug Administration, according to one study.

The study, published in the Journal for Healthcare Quality earlier this year, focused on incidents involving Intuitive Surgical’s da Vinci Robotic Surgical System over nearly 12 years, scrubbing through several data bases to find troubled outcomes. Researchers found 245 incidents reported to the FDA, including 71 deaths and 174 nonfatal injuries. But they also found eight cases in which reporting fell short, including five cases in which no FDA report was filed at all.

The FDA assesses and approves products based on reported device-related complications. If a medical device malfunctions, hospitals are required to report the incident to the manufacturer, which then reports it to the agency. The FDA, in turn, creates a report for its Manufacturer and User Facility Device Experience database.

The use of surgical robots has grown rapidly since it was first approved for laparoscopic surgery (a type of surgery that uses smaller incisions than in traditional surgery) by the FDA in 2000. Between 2007 and 2011 the number of da Vinci systems installed increased by 75 percent in the United…