By Jane Ehrhardt
Endoscopic spine surgery (ESS) has been around for decades in other parts of the world, but still lingers in its infancy in America. “If you travel to Europe—especially Germany or southeast Asia, Japan—endoscopic decompressions and discectomies are almost the gold standard,” says Daniel Kim, MD, spine surgeon with Southlake Orthopaedics and one of the first to be performing the procedure in Alabama.
The slow introduction of ESS to the U.S. likely stems from the fact that much of the development of the technique occurred in other countries. In addition, U.S. doctors are not being trained for it coming out of fellowship, and it is not something readily picked up. “Since it’s a completely different way to do spine surgery, it’s very difficult for even more experienced surgeons to just adopt it right off hand,” Kim says, who has performed over 30 procedures in the last 18 months.
Endoscopy takes minimally invasive spine surgery to its most advanced, state-of-the-art form to produce a quicker recovery time and less recurring pain for the patient. It differs from minimally invasive, micro-invasive, and laser spine surgeries. “All the work that you do at the structures of interest within the spinal canal is the same,” Kim says. “The difference is all in the collateral damage that’s required to do the job itself.”
The entry is a mere eight millimeters for endoscopy versus two or five centimeters for tubular and open portals, respectively. To reach the surgical site with the pencil-wide trocar, the surgeon enters with an intralaminar approach from the back of the spine between two laminae or the transforaminal entry from the side of the spine into the neuroforamen—a nerve passageway.
A tiny camera then inserts through the trocar and projects real-time images of the site onto a monitor in the surgeon’s direct view. “The visualization is some of the best you can have, even as opposed to a microscope because you are looking directly at the nerves, the disc, and the bony structures,” Kim says. Though the detail with the zoom function on some microscopes can match the endoscopic view, the field of view becomes very limited when using the zoom.
Once the surgeon reaches the site, the procedure mimics tubular and open surgeries for discectomies and decompressions. The tools also remain the same, but they are specially sized to fit through the small working channel.
“The freedom of motion is much less, because you’re using a single instrument through a tiny portal, so you have to learn how to navigate the equipment,” Kim says. “You can’t move the same in there because the reach is only a few centimeters from one side to the other. So you better be in the right vicinity and the right angle when you come in. That’s part of the steep learning curve with all of this.”
That learning curve grows if the surgeon chooses the transforaminal approach. “Anatomically everything looks flipped then,” Kim says, for surgeons who use the more straight-in, intralaminar entry utilized in the open and tubular options. “This is why it’s so hard to learn. It’s a whole new surgery.”
However, the small incision and smaller tools mean less trauma to the ligaments, bone, and joints—the stabilizing features of the spine—leading to a faster recovery. “There are problems that used to take weeks to months of recovery reduced to days with endoscopy,” Kim says. Most ESS procedures can be completed in about one hour with patients able to be back on their feet just a few hours after post-operative recovery.
The limitation in site access with endoscopy, though, does limit the types of procedures possible and patient candidates. ESS is not suitable for revision surgery, cases of clear spinal instability, high-grade spondylolisthesis, or cancer. Kim is also not performing fusions at this time.
Longer-term outcomes for a nerve compression problem performed using any of the three options of open, tubular, and endoscopic spine surgery appear to be similar. But the short-term recovery does differ because of far less trauma caused while reaching the surgical site. “The journey matters just as much as the end result,” Kim says. “If we can provide patients with a more comfortable and more functional recovery, that matters too.”