The SNUBH team develops a faster and safer method of vocal cord correction
Researchers at Seoul National University Bundang Hospital (SNUBH) have found that when performing “vocal cord injections” to improve patients’ voice by correcting their vocal cords, the use of a method guided by light is easier and more efficient.
According to the research team, led by Professor Cha Won-jae from the ENT department, the vocal cords can be damaged by paralysis, aging or surgery. If good contact with the vocal cords is not maintained, chronic hoarse voices or the inability to produce sounds properly may occur. Therefore, doctors inject loads of hyaluronic acid into the vocal cords to increase their volume. Vocal cord injection is a treatment that helps both sides of the vocal cords maintain contact for standing.
It is usually performed in a minimally invasive way. Yet even with an endoscopic camera, it is not easy to precisely locate the needle tip in the vocal cords due to the anatomical structure of the larynx. As a result, only a few trained professionals can perform this procedure in Korea due to the precision required.
To overcome these problems, medical scientists have developed “light-induced vocal cord injection” technology to guide the injection location with a light source device connected to the needle with precision.
Professor Cha’s team performed photo-induced vocal cord injection in 40 patients with unilateral vocal cord paralysis. As a result, none of the patients had acute complications related to the treatment equipment, and the average injection time needed to inject and position the needle was reduced.
Additionally, the operator can perform the procedure safely and accurately by gaining depth and direction information based on changes, such as the location of the light seen through an endoscope and the brightness of the needle as it enters the vocal cords. After four weeks, they also found that the treatment effect showed significant improvements on the GRBAS scale (Grade, Roughness, Breathiness, Asthenia, Strain) to assess hoarseness and roughness of voice. Additionally, aerodynamic tests such as maximum vocalization time and average exhalation rate showed significant improvement.
“This study is important because it has established clinical evidence that photoinductive vocal cord injection can compensate for the shortcomings of the original procedure,” Professor Cha said.