ALTOONA, IOWA — Laurie Featherstone says she was about to have a hysterectomy in March 2015 when her doctor asked a question she was not expecting. Did she want to have the surgeon use a robot for the procedure?

"[The doctor] said if she were me, she'd elect to have the robot," recalled Featherstone, a hairstylist from this suburb northeast of Des Moines.

The robot is the only one of its kind: the da Vinci surgical system made by Silicon Valley's Intuitive Surgical. The reasons the doctor recommended it, Featherstone recalled, included "less downtime, less scarring, and less than a 3 percent complication rate."

Featherstone, who needed the operation in part because of fibroids in her uterus, followed her doctor's advice. But a few weeks after the robot-involved procedure, complications emerged.

Excess fluids accumulated in her kidneys, an ailment called hydronephrosis. There was an injury to one of her ureters, the duct that carries urine from the kidney to the bladder. One of her doctors wrote in her medical records that he assumed "the problem is a thermal injury" and was "due to robotic hysterectomy."

Her ureter was burned and her colon damaged during the surgery, according to her medical records. Her prognosis calls for a permanent colostomy.

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"Less downtime for me turned into we are three years later and still dealing with it," said Featherstone.

Featherstone filed a lawsuit in 2017 in an Iowa county court against Intuitive and her doctor’s practice, but later voluntarily withdrew the case against Intuitive. She says she did not pursue the suit against her doctor because she ran up against the statute of limitations.

The da Vinci Surgical System is touted as a breakthrough in minimally invasive surgery. It is known to have multiple advantages, including a monitor that lets surgeons see better inside patients, a steady robotic arm allowing for more precision, and a record of faster recoveries for patients. But the da Vinci also comes with risks, including injuries like Featherstone's.

Laurie Featherstone Courtesy Laurie Featherstone

NBC News spoke to more than a dozen patients who say they were burned or otherwise injured during surgery with the da Vinci.

An NBC News analysis of adverse event reports filed in the U.S. Food and Drug Administration MAUDE database over the past 10 years showed there were more than 20,000 adverse events related to the da Vinci filed with the FDA. Intuitive Surgical, the maker of the da Vinci, filed the great majority of the reports, though some were also filed by hospitals, doctors and patients. To be sure, the da Vinci is used in a large number of surgeries and the adverse events appear to occur in a relatively small portion of the overall surgeries. The number of da Vinci surgeries performed in the U.S. has increased by 52 percent since 2013, to nearly 700,000 procedures in 2017.

More than 2,000 adverse events were categorized as involving injuries, 274 were categorized as deaths, and nearly 17,000 events were classified as device malfunctions — some minor, others more serious, including robotic arms uncontrollably going in the wrong direction and insulation cracking off and dropping inside patients' bodies.

But NBC News also found in the data that there were 12 instances of Intuitive batching large numbers of adverse events into one report. In one instance, Intuitive combined 200 injuries into a single filing.

In all, the batched filings amounted to 2,000 reports of injury of patients by the da Vinci, meaning there could be as many as 4,000 reported injuries. However, it is not known if any of the bundled injury reports duplicate injuries reported elsewhere in the MAUDE database.

The FDA told NBC News it granted permission to Intuitive Surgical to bundle multiple adverse events that are the subject of lawsuits into a single filing.

The FDA uses the database as a key tripwire to spot problems with medical devices, but it has acknowledged that the reporting system has limitations and can contain "incomplete, inaccurate, untimely, unverified, or biased data."

Medical personnel remove a donor's kidney with the da Vinci robot on March 27, 2018. BSIP / UIG via Getty Images file

At the same time, the machine has had 175 recalls in the past decade, according to an NBC News review of recalls filed with the FDA. Recalls associated with the device have steadily declined over the years, peaking in 2014 with 49 but dropped to one a year in both 2010 and 2011. There were eight in 2018. Recalls in the past two years include minor adjustments such as instruction clarifications and software updates, as well as more serious recalls such as a surgical knife that may not move when needed to cut, surgical arms that could fail, and others that could unexpectedly move.

The robot is piloted by a surgeon who sits at a console and it costs on average $1.4 million. Introduced in 2000, there are nearly 3,000 da Vincis in use in the U.S., and Intuitive has launched new models and updates throughout the past two decades.

Though companies like Google are working on rival robotic devices, the da Vinci remains alone in the marketplace. Local hospitals and surgeons promote its use, often making public pronouncements once they acquire one for their operating rooms.

In 2013 the FDA sent the company a warning letter stemming from problems like electrical arcing, in which electricity arcs from the tip of the robotic arm to the patient's flesh, causing injury, and for improperly marketing the machine for certain thyroid surgeries. The company was sued by shareholders for misleading statements about its difficulties, and in June of this year settled the class-action case for $42.5 million. The legal documents state the settlement was not an admission of fault.

In July of this year, another medical study found that payments from Intuitive appeared to "influence" doctors when they conducted research on the robot. The study found that if there was a financial relationship between the doctors in each study and Intuitive, there was a higher likelihood of studies reporting a benefit of robotic surgery.

Public records show that since 2013, Intuitive has paid over $144 million to doctors and hospitals, for education, research, and travel. The company says that the majority of the payments made to doctors were for education, such as paying doctors to train other doctors.

Dr. Robert Poston, chief of cardiothoracic surgery at SUNY Downstate Medical Center, is an avid user of the robot. He says his patients are able to recover faster, there's less blood loss, and fewer complications.

"I notice my ability to be precise is better even than with my own hands," he said.

But he also believes many surgeons begin using the da Vinci with too little training.

"It's woefully inadequate, woefully inadequate the way it's currently being done," said Poston. "We shouldn't be operating until we've done all of the training that we think is reasonable."

Surgeons operate a da Vinci Surgical robot to remove the tumor at the First Affiliated Hospital of Sun Yat-sen University in Guangzhou, Guangdong province of China on April 15, 2015. VCG / Getty Images file

Poston says while he has now done about 1,200 procedures using the da Vinci, before he did his first he had only had two hours of training on the device, and is deeply concerned that many other surgeons are inadequately trained.

"We should live in a world where we practice brutal transparency with our patients," said Poston. "So if we lived in that world we would tell the patient, ‘I’d like to operate on you, but I didn’t have the time or money to have all the training that I really think that we ought to have had. Is that okay? Is that okay? Would you be okay with that?' "

Intuitive offers a four-level training program, but cannot legally require surgeons to complete it and cannot train surgeons on patients.

In response to questions from NBC News, Intuitive Surgical said, "At Intuitive, our mission is to help surgeons safely and effectively improve patient outcomes and decrease surgical variability. Our training, systems and technologies reflect, and are informed by, our commitment to patient safety, so we offer a comprehensive, intensive training program on our technology that depends on the surgeon's capabilities — and we also strongly recommend they continue training throughout their careers. As with any medical device manufacturer, we are only permitted to train on our technology — we cannot, by law, train on clinical practice or the clinical application of our technology.

"While any surgery regardless of modality carries risk, the best evidence of the safety and efficacy of robotic-assisted surgery can be found in the more than 15,000 peer-reviewed scientific publications that are fully grounded in scientific method and that, in aggregate, support the safety and efficacy of our systems."

The FDA also said it does not have the authority to oversee training and education.

There are no national requirements regulating how much training a surgeon must have to operate using the da Vinci. The level of training is left to local hospitals and the surgeons themselves.

"The root cause here is the training," said Poston. "The willingness to sell robots to people and promote them doing surgeries when they weren’t adequately trained, the willingness of hospital credentialing committees to sign off on them and allow them to do it."

Featherstone, meanwhile, said she is concerned with making sure more patients do not get hurt and that the company improves outcomes.

"I have some guilt because I asked more questions about the shoes I put on my feet or products that I use, you know, for my skin or my hair," said Featherstone. "But I put all my faith in the doctor and didn't ask questions."

NBC News probed medical device alerts around the world as part of a global project organized by the International Consortium of Investigative Journalists, a news organization notable for its work on the Panama Papers, to examine the medical device industry. More than 250 reporters in 36 countries worked on stories that began publishing November 25, 2018.

Cynthia McFadden and Kevin Monahan reported from Iowa. Emily Siegel, Andrew W. Lehren and Pauliina Siniauer reported from New York.