June 27, 2006

Making surgery safer

Minimally invasive laparoscopic surgery carries little-known risks

By Lisa Marshall, Camera Staff Writer

In February 1991, Trudy Hamilton, a registered nurse and mother of two, checked into a Tampa., Fla. hospital for a routine laparoscopic test to determine what was causing her chronic pelvic pain. She assumed she'd be back to work in no time. Instead, she found herself doubled over in the emergency room eight days later, being prepped for surgery to repair life-threatening perforations in her colon and bowel.

The culprit was a little-known flaw in what has otherwise been heralded as a revolution in modern surgery techniques. Exploding in popularity since the 1980s, minimally invasive laparoscopic surgery has been credited with decreasing pain, scars, and recovery time for everything from gynecological tests to spine surgery. But in some rare cases, as in Hamilton's, the electrothermal equipment used to create incisions and control bleeding has been known to leak stray energy, burning other organs it passes on the way to the surgery site.

"These are instantaneous third- degree burns that will not heal. It takes a micro-second to cause a potentially fatal complication," says Roger Odell, chairman of Boulder-based Encision Inc.

For 16 years, O'Dell, a 30-year veteran of the medical device industry, has been working to prevent such complications, by creating and refining a device that can detect stray energy leaking from laparoscopic instruments and halt the procedure if it occurs. After a slow start in the 90s, O'Dell's company — founded as Electroscope Inc. in 1991 — has begun to make some headway, with its products now in place in roughly 400 hospitals across the nation, including Boulder Community Hospital, and many more around the country considering it.

At a time when unprecedented attention is being paid to patient safety, Encision officials say such laparoscopic surgery complications are more common than "anesthesia awareness," (people waking up during surgery), and wrong-site surgery — two issues that have received much media attention in recent months.

"Yet a lot of people have never heard of it," says Encision President Jack Serino.

More than 4.4 million laparoscopic surgeries are performed annually in the United States. Studies show that between 1 and 5 in every 1,000 will result in thermal injuries to the bowel, and many believe those numbers are underreported, because the damage is done out of the surgeon's view, and patients often don't know anything is wrong until the operation is over and they have been sent home.

One survey conducted by the American College of Surgeons found that 18 percent of members had experienced an incidence of stray energy during surgery, and 54 percent knew a colleague that it had happened to.

A burn to the bowel can be particularly dangerous, because it can lead to fecal peritonitis — a potentially fatal condition in which fecal matter leaks into the abdomen.

"If a patient sustains a burn to the bowel, they will go home feeling fine and show up a week later in the emergency room," says Serino.

During "monopolar electrosurgery" — by far the most common kind of laparoscopic surgery — a long metal rod wand is inserted into the body, accompanied by a miniature video camera that allows the surgeon to see what he or she is doing. Radio waves flowing through the wand provide the heat source that allows for cutting and bleeding control. If there is even the tiniest hole in the instrument — which can be caused by repeat trips to the autoclave for sterilization — heat can escape, resulting in burns. Even if the instrumentation is intact, a phenomenon caused "capacitive coupling" can occur, allowing electrical current to pass through intact insulation, beneath the skin and out of view of the camera.

Encision has tackled the problem on two fronts, creating wands with stronger insulation said to prevent capacitive coupling, and a patented Active Electrode Monitoring system that sounds an alarm and discontinues the current if a breach in the equipment is detected.

Over the years, the equipment has been refined, to make it easier to use and less expensive. In 15 years, O'Dell says, there has not been one confirmed stray energy burn using any of Encision's equipment.

"It makes electrosurgery safe," says Dr. Gerald Kirshenbaum, a Denver surgeon who has been using Encision's equipment since it first came out. "I don't think there is a general appreciation out there of the fact that there are problems with it."

Dr. Thomas Robinson, an assistant professor in the department of surgery at CU Health Sciences Center, says stray energy burns are definitely a concern on the radar screen of minimally invasive surgeons. But he believes recent media reports about the subject — including a recent story in the New York Times — have been a bit "dramatic."

"Do insulation failures happen? Yes. They definitely do," Robinson says. "It's talked about a lot but it is extremely rare."

Robinson says the hospitals he works at, including University of Colorado Hospital, do not use the Active Electrode Monitoring system, but there are other systems in place for doctors and nurses to inspect equipment prior to surgery to assure it is safe. He believes cost may be a factor in Encision's slow growth over the years. (The company went public in 1996 at $10.50 per share but now trades below $3.)

"The morbidity is very high, which justifies the cost even if it is very low incidence," Robinson says. "But honestly, I don't think this is going to take off like wildfire."

Encision is not the only medical device company working to address the issue of electrosurgical burns in laparoscopy. Mobile Instrument Service and Repair Inc. makes a product called InsulScan, that detects holes and cracks in equipment prior to surgery.

Hamilton, now 53, had to have part of her bowel removed and took more than eight months to recover after her surgical mishap. She still has to eat a special diet and has been hospitalized numerous times since, due to lingering health complications.

She sued her physician for malpractice and was awarded an undisclosed amount in 1994 by a jury.

Today, she continues to be an outspoken advocate for better monitoring.

"It breaks my heart that it hasn't been used more before now," Hamilton says. "That someone can prevent the kind of things that I went through and that my sons went through, but isn't doing it, really bothers me."

Contact Lisa Marshall at (303) 473-1357 or marshalll@dailycamera.com.