Autologous Platelet-Poor Plasma Gel for Injection Laryngoplasty

PURPOSE: To overcome the potential disadvantages of the use of foreign materials and autologous fat or collagen, we introduce here an autologous plasma gel for injection laryngoplasty. The purpose of this study was to present a new injection material, a plasma gel, and to discuss its clinical effectiveness. MATERIALS AND METHODS: From 2 mL of blood, the platelet poor serum layer was collected and heated at 100degrees C for 12 min to form a plasma gel. The plasma gel was then injected into a targeted site; the safety and efficacy thereof were evaluated in 30 rats. We also conducted a phase I/II clinical study of plasma gel injection laryngoplasty in 11 unilateral vocal fold paralysis patients. RESULTS: The plasma gel was semi-solid and an easily injectable material. Of note, plasma gel maintains the same consistency for up to 1 year in a sealed bottle. However, exposure to room air causes the plasma gel to disappear within 1 month. In our animal study, the autologous plasma gel remained in situ for 6 months in animals with minimal inflammation. Clinical study showed that vocal cord palsy was well compensated for with the plasma gel in all patients at two months after injection with no significant complications. Jitter, shimmer, maximum, maximum phonation time (MPT) and mean voice handicap index (VHI) also improved significantly after plasma gel injection. However, because the injected plasma gel was gradually absorbed, 6 patients needed another injection, while the gel remained in place in 2 patients. CONCLUSION: Injection laryngoplasty with autologous plasma gel may be a useful and safe treatment option for temporary vocal cord palsy.

Classificação de sinais de voz utilizando a transformada Wavelet Packet e redes neurais artificiais / Classification of speech signals using the wavelet packet transform and artificial neural networks

This work proposes a disphonic voice classification system using Wavelet Packet Transform (WPT) and Best Basis Algorithm (BBA) as dimension reducer and 6 Artificial Neural Network (ANN) as specialist system...

Preliminary Results of Vocal Fold Augmentation by Injection of Autologous Fascia / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Vocal fold augmentation by injection under direct visual control is a quick, easy, and accurate operation. However, when autologous fat or bovine collagen is used, both showed considerable resorption over time and gave variable results. Autologous fascia is a newly introduced graft material and has a low metablolic requirements with also a relatively stable histological characteristics. The goal of this study was to confirm the autologous fascia as a new injection material of vocal fold augmentation and assess the impact of the fascia injection on voice acoustics. MATERIALS AND METHOD: Six subjects with vocal cord palalysis and three with sulcus vocalis were analyzed after injection. The temporalis muscle fascia and abdominal fat were harvested. The fascia was cut into small pieces and injected using the pressure syringe with a 18 G needle on the lateral aspect of the vocal fold under the direct visual control. The preoperative and postoperative parameters including jitter, shimmer, signal to noise ratio, and maximum phonation time were analyzed. RESULTS: There was significant improvement in all parameters measured in the group of vocal cord palsy. But there was no definite improvement in the sulcus vocalis group. There was only one laryngeal complication, the postoperative granuloma at leakage site of injection. CONCLUSION: According to these preliminary results, it is suggested that vocal fold augmentation by injection of autologous fascia can be a stable and effective surgical treatment for vocal cord palsy.