The long-term focus of our research is to design, test and implement innovative surgical strategies for safe and effective restoration of vocal fold (vocal cord) impairments and injuries (Figure1). Historically, physicians have implanted various materials into damaged vocal folds in an attempt to restore voice. Those implants have allowed only limited success since many are temporary, some cause unfavorable reactions and some migrate out of where they are placed. It is therefore our goal to try to produce an ‘ideal’ implant that will more completely facilitate return of normal voice in patients. An ‘ideal’ substrate for implantation into the vocal fold is one that is: safe, tissue compatible, durable, exhibits similar viscoelasticity to the native vocal fold, readily available, easy to deliver, and affordable.
Figure 1: View of normal dog vocal folds (VF’s) looking down the throat
Our work introduces the use of local tissue engineering for implantation, where native tissues from the external larynx (voice box) are delivered into the superficial layers of the vocal fold. This local implant is showing promise as an ideal implant. This is due mostly to the fact that the blood supply to the implant remains intact- greatly enhancing its durability and the locally derived tissues will not induce tissue rejection. Additionally we are looking to develop biodegradable nanofibers (absorbable suture materials that are spun into extremely thin fibers and shaped into useful forms) that act as a scaffold to be implanted into the vocal fold alone or impregnated with growth factors, stem cells or other pharmaceuticals that enhance its effectiveness.
To evaluate the performance of our implants, we utilize state of the art diagnostic equipment, including but not limited to: endoscopy, high speed digital imaging, acoustic evaluation, laser doppler, histochemistry, immunohistochemistry, immunofluorescence (Figure 2), rheology, and high resolution MRI (Figure 3). We, along with our collaborators, are pioneering the invention and use of suture anchors in the cartilage of the vocal fold to secure our implants in place, the use of temporary and permanent biologic tissue dyes for histologic identification weeks to months post-implantation, and the invention and streamlining of vocal fold cannulation and dilatation instrumentation.
Figure 2: Immunoflourescence staining of an implanted dog vocal fold at 20x
Figure 3: Examples of high resolution Magnetic Resonance (MR) images from our
The outcome of our research has the potential to provide long term, viable solutions to vocal fold defects in human patients, greatly improving their quality of life and their ability to communicate.
Additional Research Projects
We are also striving to improve and further current knowledge about the following technologies and conditions:
The Laryngeal Dissection and Surgery Guide
Dr. Seth Dailey and his collaborative efforts with Dr. Sunil Verma and others produced a fine addition to the literature in Otolaryngology-Head & Neck Surgery, The Laryngeal Dissection and Surgery Guide (Thieme Publishers).
|*Figure 1:* View of normal dog vocal folds (VF’s) looking down the throat through an endoscope. Arrow shows endotracheal tube. *Figure 2:* Immunoflourescence staining of an implanted dog vocal fold at 20x magnification. Clockwise presentation: Arrowhead points to red cells undergoing regeneration, the narrow arrow illustrates black areas of fat within the implant, squiggly arrow shows otherwise unstained cells (counter-stained for contrast), thick arrow illuminates one of the blood vessels of the implant (bright green circles), and the curved arrow shows small shadows created by the tattoo ink used to outline the perimeter of the implant. *Figure 3:* Examples of high resolution Magnetic Resonance (MR) images from our research. The first image shows the complete structure of a normal dog vocal fold in 2D. The pink image illustrates only the muscular component of a normal dog vocal fold in 3D. The green image illustrates areas of fat (light green areas) in a normal dog vocal fold in 3D.|