In a first-of-its-kind study, Mount Sinai researchers have discovered a novel technique to monitor laryngeal and vagus nerve function while patients are under anaesthesia during otolaryngology and neurosurgery procedures. The findings could save patients from vocal paralysis, maintain their swallowing function, and transform the way doctors perform surgeries.
Laryngeal nerve injuries following thyroid or anterior cervical spine surgeries affect approximately 10 percent of patients. To prevent these injuries, doctors typically monitor these nerves intermittently by stimulating them at various times through the procedure. But with intermittent monitoring, a possible nerve injury can be missed. Continuous stimulation allows doctors to see damage before it occurs and take preventative measures, but until now the only method of continuous monitoring has required doctors to place an electrode around the vagus nerve in the neck (this cranial nerve extends from the brainstem to the abdomen and helps supply voice and swallowing functions and control heart, lungs and digestion), which is invasive for the patient and can cause surgical complications.
Mount Sinai researchers recently developed a new, less invasive technique to continuously oversee the nerve function throughout thyroid procedures and cervical spine fusions. This novel technique relies solely on a special type of breathing or endotracheal tube, inserted by the anaesthesiologist at the start of the surgical procedure. They use the tube to both stimulate and monitor nerve responses during the entire surgery, which has never been done before. This technique allows surgeons to see how different surgical manoeuvres affect nerve function, and then change their approach to prevent post-surgical voice and swallowing complications resulting from nerve dysfunction during the procedure. According to their research results, this technique may improve patient outcomes and lower complication rates.
"This simple technique will likely have wide-reaching effects by greatly enhancing our ability to monitor the vagus nerve in the head and neck during neurosurgical and cardiothoracic surgeries. It requires no equipment other than a monitored breathing tube, and this type of tube is generally already used in most of these surgeries," said lead investigator Catherine Sinclair, MD, FRACS, Assistant Professor, Otolaryngology, Icahn School of Medicine at Mount Sinai. "Never before have we been able to monitor both sensory and motor branches of the vagus nerve. The ability to monitor sensory function for the first time is a huge breakthrough and will hopefully translate into improved patient outcomes."