Ron Zimmerman

April 06, 2011

April 6, 2011 (San Antonio, Texas) — Surgeons at Maimonides Medical Center in Brooklyn, New York, have devised a method to project a "laser roadmap" intraabdominally to visually guide surgeons in precisely placing mesh and transfascial sutures to repair ventral hernias, investigators reported here at the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) 2011 Annual Scientific Session and Postgraduate Course.

Good outcomes in laparoscopic ventral herniorrhaphy (LVH) require precise mesh and suture placement. Despite this, LVH is routinely performed using only visual estimations, which may explain why so many of these procedures have a high recurrence rate, requiring additional surgeries, according to Matthew Dixon, MD, a general surgery resident at Maimonides Medical Center and one of the study investigators.

Dr. Matthew Dixon

Dr. Dixon explained to Medscape Medical News that ventral hernias are common, representing about 10% of all hernias. "There are about 150,000 ventral hernias repairs done every year in the [United States]," he said. "Regardless of whether you are using a laparoscopic or open technique, they have a high rate of recurrence — up to 12% at 5 years, and up to 23% at 13 years. So recurrence really represents a serious problem. And with increasing attempts at repairing the same hernia, you have a progressively increased chance of recurrence."

Employing an external laser projector and an internal spherical convex mirror at the end of a cannula, Dr. Dixon and colleague and principal investigator Danny Sherwinter, MD, bounced a 2-dimensional grid or "roadmap" off the inside of a patient's abdomen. The peritoneal surface and the projected interperitoneal laser map were viewed intraabdominally, through the laparoscope. The map indicates the precise center of the hernia, the correct mesh overlap, and the proper transfascial suture position and corresponds precisely to printed markers on the mesh.

Dr. Dixon explained that his laser-guided positioning system is designed to overcome the current shortcomings of LVH repair. "They may fail because of a lack in the surgeon's experience, or inadequate overlap of the mesh covering the hernia defect, or inaccurate placement of your transfascial sutures," he said. "Our idea was that if we could develop a roadmap that could be projected on the interior abdominal wall, that would increase our accuracy of [placement of] transfascial sutures, [and] may decrease recurrence rates of these hernias."

He added, "In our procedure, you would have this cannula delivering the laser image actually going through the defect in the abdominal wall where the hernia is coming out of. So after you've reduced the hernia back into the abdomen, you create a hole in the defect, and you stick the cannula through that defect — you create the roadmap that way. In the future prototypes, it may be advantageous to create another incision. Also, you don't have to go through the defect itself."

The procedure has been successful in simulation models and in dogs, but Dr. Dixon explained that his team needed to overcome a major obstacle: "Using a laser was a big frustration of ours — coming up with a way to be able to see the images inside without being blown out by the lights from the laparoscope itself. We solved the problem in a way I can't discuss. But that was a big hurdle for us that we were able to overcome, and that may be the reason why other people haven't tried internal laser guided maps."

Gyusung Lee, MD, a surgeon from the University of Maryland, Baltimore, has some reservations about the current prototype, but he foresees widespread eventual adoption of the laser-guided system.

"It's not there yet," Dr. Lee said, "because one doctor asked if it's manipulatable, to change the location and things like that, but the presenters told us the prototype doesn't have that because of the fixed nature of the mirror. Future development will consider that, to make it where the cannula doesn't come from the hernia side but from another place, and also have the mirror manipulation capability, so that the projection can be adjusted accordingly."

He continued, "I think once they work out these problems, that it will be useful for surgery, particularly for younger surgeons who do not yet have a lot of experience with hernia repairs. It's very difficult for junior surgeons to estimate the size of the hernia and the fixation location for the mesh at the repair site, so the laser-guided map will be very beneficial. In orthopedics you have image-guided surgery, which wasn't done before, but with the guides now available, it's very helpful in reducing errors and making it easier for the surgeon to perform."

Dr. Sherwinter, Dr. Dixon, and Dr. Lee have disclosed no relevant financial relationships.

Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) 2011 Annual Scientific Session and Postgraduate Course: Abstract ET003. Presented April 1, 2011.