Teodor P. Grantcharov, a professor of surgery at the University of Toronto, said the use of recording equipment in operating rooms helps physicians. “If we don’t know what we’re doing wrong, we’ll never improve,” he said. (St. Michael's Hospital of Toronto)

Chris Nowakowski’s wife died in Wisconsin during what should have been a routine procedure on her pacemaker. Danny Long’s wife in North Carolina suffered catastrophic neurological injury during a surgery to relieve numbness in her extremities. A doctor perforated the colon and esophagus of Deirdre Gilbert’s daughter in Texas, then operated on her after she was dead.

In each case, the families still don’t know the full story of what happened to their loved ones because of a lack of documentation and an inability to pursue a costly lawsuit. They are relatives of an estimated 400,000 a year people who die in the United States of preventable medical errors, the third-leading cause of death after heart disease and cancer. But the families say they could have known much more if cameras had been installed in the operating rooms, recording the actions and movements of the doctors and staffers involved.

They are enthusiastic supporters of a growing movement that is seeking to require hospitals and surgical suites to have video and audio recording capability. Now, a surgeon in Toronto has built a “black box” that synchronizes a patient’s physical data with video and audio recordings of an operation, enabling doctors to review their work the same way athletes watch video of their performances. And he said he has lined up two U.S. hospital systems to take part in the first testing of the system.

“If we don’t know what we’re doing wrong, we’ll never improve,” said Teodor P. Grantcharov, a professor of surgery at the University of Toronto. “This is what many other ­high-performance industries have been using for decades.”

A bill that would require cameras in every operating room in Wisconsin has been introduced in the state legislature, and supporters say that lawmakers in other states are closely watching the bill’s progress. The proposed legislation, known as the “Julie Ayer Rubenzer Law,” is named for a Wisconsin woman who died after she was given excessive amounts of propofol — the same anesthesic that killed singer Michael Jackson in 2009 — during breast-enhancement surgery.

Rubenzer’s brother, Wade Ayer, founded the National Organization for Medical Malpractice Victims and helped draft the bill, which is supported by patient-advocate groups around the country. Ayer said video and audio recordings can capture the reasons behind “adverse events,” as the medical industry terms them, and deter inept or simply bad behavior by medical personnel — such as the anesthesiologist in suburban Washington who can be heard harshly criticizing her patient in an audio recording made by the patient. The physician was hit with a $500,000 jury verdict.

Currently, re-creating what went wrong in an operating room involves a mixture of memories and whatever notes were taken at the time or shortly afterward, a vague combination that vexes families trying to get to the truth about a failed procedure or a fatal complication. Recording surgeries “offers transparency, truth and accuracy,” Ayer said, “in collecting data for the medical record and testimony. It offers data and insight for medical boards and even prosecutors. It offers oversight and policing.”

The medical industry is treading cautiously. The American Hospital Association, the American Medical Association and the American College of Surgeons all declined to comment for this article. In 2005, the AMA adopted a policy on filming patients in health-care settings — it encouraged the practice for educational purposes — but focused on patient privacy and on filming only those who give their consent.

But the health-care industry has flexed its muscle where needed, sometimes driven by concerns about the effects that video recordings could have on medical malpractice lawsuits as well as the cost of installing and maintaining complex recording systems. A bill in Massachusetts that would require hospitals to allow recording by a licensed videographer, at the patient’s expense, has repeatedly failed in recent years in the face of opposition from hospitals, according to news media reports.

In Wisconsin, Ayer said he has encountered opposition from the medical industry. But state Rep. Christine Sinicki (D) has pressed ahead with what would be the first law in the country to require cameras in operating rooms. “After hearing stories from families affected by malpractice,” Sinicki said in an interview, “a lot of people felt the way to rein this in and catch it is to record everything in the operating room.”

But there are “fantastic privacy issues” with cameras in operating rooms, not only with patients but also with doctors and staffers, according to Bruce A. Cranner, a medical malpractice defense lawyer in New Orleans who is a former chair of the Defense Research Institute’s Medical Liability and Health Care Law Committee. “Health-care providers have a justified right to be able to talk among themselves about a patient without fear that [they are] going to be second-guessed or overheard.”

Cranner also suggested that cameras would not necessarily capture the key parts of an operation and that “we are going to have to have somebody explaining for the TV what’s going on, like PBS’s ‘Nova’. That’s not what medicine’s for; it’s not Hollywood.”

Ayer said Cranner is wrong. “They already have cameras in operating rooms,” he said. “That’s how they train medical students.” Although cameras may not always be conclusive on the finer points of a surgery, Ayer said, they would clearly show who was present during a procedure and when, details that often are at issue.

Ayer has also begun lobbying members of Congress in order to judge interest in a federal law regarding surgical cameras. He also is pushing for a national database of doctors who have had their licenses taken away after they made medical errors. The license of the doctor whose actions killed Ayer’s sister was revoked in Florida, but he now practices in Pennsylvania, public records show.

Some advocates for operating-room cameras say the devices can only help. They add that tort reform in many states limits damages in malpractice cases, discouraging lawyers from taking on cases without clear-cut evidence — such as video.

“The medical records of what happened during surgery are often incomplete,” said John T. James of Patient Safety America, whose 19-year-old son died as a result of medical errors in Texas in 2002 and who authored a study that estimated that 400,000 people die of adverse medical events a year. “Cameras push us in the direction of the truth,” he said. “And if the surgical team knows they’re being videotaped, they’re going to do better.”

And that was the impetus for the University of Toronto’s Grantcharov to create a “black box” to record operations: improving surgeons’ performance. “The initial idea wasn’t to make it available to be used in the courts,” he said. “This is a way for our profession to reflect critically on what we do” and share knowledge industry-wide, not simply where cameras are being used.

He said that in one pilot project involving 54 procedures, there were adverse events in 38 of them, and 75 percent of the problems were not noticed by the surgical team. Using the video, audio and patient data from an operation can help surgeons learn from their mistakes, he said.

“In the majority of cases,” Grantcharov said, “the data will protect doctors in court. We will see a reduction of malpractice claims.” But he said that cameras and data must be rolled out carefully. “If it’s used for destructive purposes, the profession will shut it down. It’s a very delicate topic right now.”