3D DOC "I would rather take lower resolution in 3D than higher resolution in 2D," says Daniel D. Eun, MD.

In GI endoscopy, laparoscopic cholecystectomy, arthroscopic joint repair and other minimally invasive procedures, the image is everything. And ever since high-definition video displays made the leap from consumer entertainment to surgical standard, providers have been wondering what the next big advance in imaging will bring to the OR table.

At present, all eyes are on ultra-high definition, also known as 4K, a new video format that quadruples the resolution of "full HD" for an image composed of more than 8 million pixels. The providers pioneering the technology for clinical use say it offers even more detailed images and greater color accuracy, and medical equipment manufacturers are developing camera heads and other hardware to capture and process these pictures. But there's still a case to be made for 3D HD video, which literally adds another dimension to surgical visualization. While it hasn't taken the nation's living rooms by storm the way that HD did, 3D is transforming how surgery is done.

"It changed the fundamentals"
Surgeons suffered a huge loss of sensory input in the transition from open to minimally invasive surgery and from their eyes to endoscopic and laparoscopic cameras, not the least of which involved their suddenly flattened binocular vision.

"One of the key weaknesses of traditional laparoscopic surgery is looking through a 2-dimensional camera and at a 2-dimensional screen," says Daniel D. Eun, MD, an associate professor of urology and the director of minimally invasive robotic urologic oncology and reconstructive surgery at Temple University School of Medicine in Philadelphia, Pa. "The way you operate in the belly, every surgical motion is different because you don't have the depth of view from stereoscopic vision."

The introduction of the robotic surgical system — the camera and console of which enable binocular vision — restored surgeons' missing sense of depth perception. Manually maneuvered, dual-optic scope systems followed: with the help of lightweight, polarized sunglass-style lenses to unscramble displayed images, they made 3D HD views more affordable to surgical facilities as well as more accessible to assisting members of the surgical team.

"It changed the fundamentals of a lot of things," says Dr. Eun. "With stereoscopic and high-definition video, you get the best of both worlds, magnification and depth. I can see exactly where I am and have a greater understanding of the anatomy."

This awareness of sizes and spatial relationships on the millimeter level allows surgeons to dissect tissue or place sutures with more confidence and safety. "I wouldn't say, given what I do, that 3D HD is allowing us to do new types of operations. I don't think we're at that point yet," he says. "But for the operations I am doing, it provides important assistance. Allowing me to discriminate where different tissue is, sparing small structures, separating tiny 1 mm vessels, nerves and lymphatic tissue. Letting me know that I'm next to a critical blood vessel, so I don't want to cut too deep."

While Dr. Eun sees 3D surgical imaging becoming more of a mainstay in academic facilities, where it will have great value in teaching — "3D is a huge part of the ability to teach and see what trainees are doing," he says. "It's a lot harder to teach in 2D." — ?he adds that it is beneficial for any surgeon to get a deeper view. "I would rather take lower resolution in 3D than higher resolution in 2D," he says.

LOOK INSIDE The remote console of a robotic surgical system offers binocular vision for depth perception.

Trialing the technique
While the experiential, anecdotal testimony of users and instructors like Dr. Eun describes how 3D HD video can assist surgical technique, there is no solid proof that its visual effects will improve your patients' outcomes over the long term. Still, the technology has been the subject of clinical research worldwide. If you're not yet sold on its benefits, here are 4 other evidence-based reasons that you might want to check it out.

1. It will be easy for your surgeons to learn. In order to determine the steepness of the learning curve associated with 3D video technology, researchers at the University of Patras in Greece documented the difficulties faced by an experienced laparoscopic surgeon as the system was implemented in the OR.

They observed him performing 15 consecutive, unselected cases over the course of 30 days, including laparoscopic extraperitoneal radical prostatectomies, nephrectomies and partial nephrectomies and reported, in the Journal of Endourology online in December, that "The transition from 2D to 3D laparoscopy for the expert surgeon seemed to be very rapid without compromising the efficacy of the operation or patient safety." (tinyurl.com/q7lx6us)

2. It increases efficiency and ergonomic satisfaction. Urologists at Kansai Medical University in Japan conducted a head-to-head comparison of 3D HD's and 2D HD's abilities through the timing involved in a complex maneuver as well as surgeons' self-reported capability to complete it and their self-reported fatigue afterward.

For the multi-center study, published in the Nov. 1, 2014 issue of the journal Surgical Endoscopy, 122 patients undergoing laparoscopic radical prostatectomy were randomly assigned to a 2D or 3D group. Their surgeons were timed in their performance of vesicourethral anastomosis, "which is technically demanding and may include a number of technical difficulties considered in laparoscopic surgeries," the researchers write.

While the 3D group's mean completion times were not significantly shorter than the 2D group's (26.7 versus 30.1 minutes, respectively) and there was little difference in their self-reported fatigue, the 3D group showed higher ability and satisfaction levels.

"Using a 3D imaging system in LRP may have only limited advantages in decreasing operation times over 2D imaging systems," say the researchers "However, the 3D system increased surgical feasibility and decreased surgeons' effort levels without inducing significant fatigue." (tinyurl.com/pv3tlub)

3. 3D is faster, even among larger patients. A retrospective review of 147 total laparoscopic hysterectomy cases by physicians at the Bagcilar Education and Research Hospital in Istanbul, Turkey, found no difference in complication rates between cases conducted with 3D and 2D visualization systems.

The mean time it took to complete the surgeries, on the other hand, showed a significant difference: 134.2 minutes for 2D operations and 116.8 minutes for 3D ones. Plus, "the operation time among obese patients was significantly shorter in those in the 3D laparoscopy group than those in the 2D group," write researchers. Their study appeared in the Archives of Gynecology and Obstetrics in October 2014. (tinyurl.com/o96adh7)

4. The glasses are actually quite effective. Sure, your OR looks like a Hollywood photoshoot when your surgical team's wearing the polarized lenses to see 3D effects onscreen, but it turns out the glasses are the most effective technology, at least for now, according to a study appearing in the August 2014 issue of Surgical Endoscopy.

Researchers at Technical University Munich in Germany rated the performance of 48 participants with varying levels of laparoscopic experience when they were set to a lap suturing task using 2D HD and a 3D alternative.

"Almost all performance parameters were superior with the conventional glasses-based 3D display compared to the 2D display and the autostereoscopic display," which did not require glasses to present depth-perception, the study notes. Participants who wore glasses sutured faster, more precisely and with more economy of movement, and even "complained of impaired vision while using the autostereoscopic monitor."

And yet, the participants who used a third 3D option — ?a no-glasses display custom-built for the study that used mirrors to deliver depth perception — scored the highest of all and demonstrated how further research can further the technology of seeing into the surgical site. (tinyurl.com/nhv45cq)