Eyes on TONES

eyes on TONES: Pioneering a New Field of Brain Surgery

 

On Kris Moe’s bookshelves, pink plastic skulls exhibiting various pathologies sit side by side with antique medical texts — both testament to the surgeon’s passion for treating brain diseases and traumatic injuries.

TONES is so minimally disruptive that “patients often ask to go home the next morning.”— Kris Moe

Moe, M.D. ’89, Res. ’91, ’94, is a UW associate professor in the Department of Otolaryngology-Head and Neck Surgery and chief of the Division of Facial Plastic and Reconstructive Surgery. His desire to reduce the pain, scarring and recovery time associated with traditional open-brain surgery or transnasal surgery led him to develop a game-changing new surgical procedure. The procedure, called TONES, is performed in only two places in the United States: UW Medicine and University of California at San Diego.

“Scarless” brain surgery

In his office, Kris Moe illustrates how a TONES procedure approaches the brain through the eye socket.

TONES — transorbital neuroendoscopic surgery — enables a range of brain procedures through the eye socket, rather than through the nose or via a traditional, open craniotomy, where a section of the skull is temporarily removed to access the brain.

Using TONES, surgeons access the brain by making a small incision next to the eye or through the eyelid. While a surgical assistant holds the passage open with a retractor and suction, the surgeon enters with an endoscope — a long tube containing a light and a camera — and an ultrasonic bone aspirator to cut out a small section of the thin bone around the eyelid. With this approach, the brain does not need to be lifted in order to perform a procedure, and operating time is reduced because the skull does not need repair.

TONES has been used to repair fractures, remove tumors and abscesses, seal cerebrospinal fluid (CSF) leaks, and treat optic-nerve decompression and epistaxis (i.e., severe nosebleeds). The process reduces pain and decreases recovery time. Because the incisions are hidden in the folds around the eye, TONES generally leaves no visible scar, even in patients who have sustained extensive injuries. Often stitches are unnecessary.

In fact, TONES is so minimally disruptive that, even after major surgery, “patients often ask to go home the next morning,” Moe says. “Sometimes they’re only taking one pain pill.” Best of all, he adds, after some 150 endoscopic orbital and transorbital surgeries, “we have not had any serious complications from this procedure.”

A tale of two specialties

Moe earned an M.D. and completed residencies in surgery and otolaryngology at UW Medicine. During fellowships at the universities of Bern and Zurich in Switzerland, he developed skills in skull-base surgery and facial plastic surgery that, in the United States, would have been outside the realm of his specialty training.

Later, when Moe was performing transnasal pituitary tumor surgery and orbit-repair surgeries at the UC San Diego School of Medicine, the seeds of a new idea were sown.

“These concepts started coming to me,” Moe explains. “I had two interests — facial plastic surgery and skull-base surgery — transorbital surgery is where these intersect.” Upon his return to UW Medicine in 2006, Moe began pursuing the idea with colleagues.

Teamwork was key to developing TONES. “The UW offers a really great collaborative working environment,” says Chris M. Bergeron, M.D., Fel. ’08, assistant professor of surgery in the Division of Head and Neck Surgery at UC San Diego Health System. Bergeron trained with Moe at UW Medicine and helped develop TONES. “In doing pituitary surgeries together, we began to wonder, ‘What stands in the way of us getting to that spot in the brain?’”

Approaching the skull base or the front of the brain from above means performing a full craniotomy, resulting in a large, ear-to-ear scar. And when approaching that area from below via transnasal surgery, the size of the nostrils limits the number of instruments that can be used at one time, as well as the number of hands that can work at once.

In addition, says Manuel Ferreira, M.D., Ph.D., Fel. ’10, UW assistant professor in the Department of Neurological Surgery and co-director of Skull-base and Minimally Invasive Neurosurgery at Harborview, “the big downfall with transnasal approaches is the morbidity associated with cerebrospinal fluid leaking.”

“When you leak this fluid into a non-sterile environment, the risk of meningitis is high,” Ferreira says. While the natural barrier between the brain and the pituitary lowers this risk in transnasal pituitary tumor surgery, treating pathologies such as skull-base tumors and trauma-induced CSF leaks with transnasal surgery is more risky.

“Going through the eye, you’re going from a sterile space to a sterile space,” Ferreira explains. “You get the benefit of greater access, and the lobes of the brain hold pressure on your new construct, which helps prevent the spinal fluid leaking.”

After developing the technique on cadavers, Moe and Bergeron began using TONES on patients with post-traumatic injuries, and then on patients with other pathologies. “The results are phenomenal,” says Ferreira.

When performing TONES procedures, physicians watch a monitor to assess the progress of the endoscopes — instruments central to minimally invasive surgery.

Minimally disruptive surgery

“Every operation causes some degree of trauma to the body,” says Carlos A. Pellegrini, M.D., UW professor, chair of the Department of Surgery and Henry N. Harkins Endowed Chair in Surgery. With its small entry sites and use of miniaturized cameras, TONES keeps entry trauma to a minimum.

“We’re trying to go from open surgery to minimally invasive surgery to minimally disruptive surgery,” Moe explains. “We want to get in, do what we need to do to effect a cure, and then leave no tracks.” Key to achieving this result is the use of endoscopes, which provide increased lighting and magnification. Endoscopes dramatically improve vision compared to the naked eye and enable surgeons to see around obstructions and visualize areas of the brain that would not otherwise be visible.

“It occurred to me in repairing orbit fractures that endoscopes would be useful for TONES,” says Moe. “They are excellent for surgery and for teaching,” he says, because they allow team members and residents to observe endoscopendoscopic images on multiple monitors. In the future, flexible robotic endoscopes will further increase the effectiveness of TONES.

Before and after: saving lives, speeding recovery

“I don’t think I would be the same man I am today if I hadn’t gone to see Dr. Moe,” says William (Bill) Arnold, a resident of Peter’s Creek, Alaska.

Arnold had a chronic runny nose, but it wasn’t caused by a cold. It was a CSF leak. Nervous about the idea of a traditional craniotomy proposed by surgeons in Anchorage — “I didn’t want a shunt inside my head,” he explains — Arnold was ultimately referred to Moe in Seattle.

Moe diagnosed the cause of the CSF leak immediately: an encephalocele, or brain hernia (a protrusion of the brain through an opening in the skull). He performed a TONES procedure to remove the hernia and seal the opening.

“I don’t think I would be the same man I am today if I hadn’t gone to see Dr. Moe.”— Bill Arnold

“If you’d seen me when Dr. Moe dismissed me from the hospital, you would never know that I’d had a brain operation,” Arnold says. “I was back to work within six weeks, with no memory loss. I credit my life to this man.”

The short recovery time associated with the procedure allows other treatments to proceed with little delay. Ferreira cites the case of a patient who’d had a very large cranio-facial resection a decade ago to treat an olfactory neuroblastoma (a cancerous tumor that develops from nerve tissue). When the tumor recurred, Ferreira and Moe performed TONES, rather than a traditional craniotomy.

“If you did [a craniotomy], you’d have to wait another month to six weeks for healing before starting chemotherapy and radiation,” Ferreira explains. But after the TONES procedure, the patient was able to start radiation a few days later.

Dodging tomatoes and pushing envelopes

TONES is an adaptation of minimally invasive techniques already in use at UW Medicine, says Richard G. Ellenbogen, M.D., UW professor and chair of the Department of Neurological Surgery and the Theodore S. Roberts Endowed Chair in Pediatric Neurosurgery. “That was the beauty of it,” he says. “It wasn’t a new skill set, just a new application.”

“The next generation of physicians has to be versed in these techniques.”— Anthony M. Avellino

Together, Ellenbogen, Moe and Bergeron published the first article about TONES in the September 2010 issue of Neurosurgery.

“We’re preparing to dodge tomatoes from the establishment,” says Bergeron. “That’s how medicine works — there’s a healthy degree of skepticism about anything that’s new.” In fact, because TONES represents a paradigm shift in neurosurgery, the review process for the article included extra scrutiny.

Manuel Ferreira demonstrates transnasal endoscopic and TONES procedures to a student in the ISIS lab at Harborview Medical Center. ISIS — the UW’s Institute for Simulation and Interprofessional Studies — allows trainees and others the opportunity to hone surgical skills before working with patients.

While the Neurosurgery paper has prompted some of the larger hospitals in the country to explore the technique, currently TONES is being performed in the U.S. only at UW Medicine and at UC San Diego, where Bergeron teaches the technique to residents and is developing a program with neurosurgery. A former fellow of Moe’s, Holger G. Gassner, M.D., is also performing TONES at the University of Regensburg, Germany.

“As everything in surgery is going toward this minimally invasive route, the next generation of physicians has to be versed in these techniques,” says Anthony M. Avellino, M.D., Res. ’00, FACS, MBA, UW professor in the Department of Neurological Surgery and director of the UW Medicine Neurosciences Institute. At UW Medicine, he says, otolaryngology and neurosurgery residents and fellows rotating through Harborview are involved in TONES and other minimally invasive surgeries performed by Moe and Ferreira.

Moe, Ellenbogen, Bergeron and Ferreira have all given presentations about TONES at hospitals, meetings and conferences — locally, around the country and internationally. And a new skull-base surgery lab in the University of Washington’s Institute for Simulation and Interprofessional Studies (ISIS) will allow neurosurgeons and otolaryngologists from other hospitals to learn the technique this year.

“The real leaders in the field and young people are very excited about TONES,” says Moe. A leading endoscopic surgeon, he says, calls TONES “an entire new field of surgery.”

And, Bergeron adds, “we continue to push the envelope.”

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