Histopathologic Evaluation of Hyaluronic Acid and Plasma-Rich Platelet Injection into Rabbit Vocal Cords: An...

Area of Science:

• Otolaryngology
• Regenerative Medicine
• Biomaterials Science

Background:

• Vocal cord paralysis management often involves injections.
• Ideal injection materials require specific characteristics like longevity, availability, biocompatibility, and ease of use.
• Hyaluronic acid (HYA) and platelet-rich plasma (PRP) are potential candidates for vocal cord injections.

Purpose of the Study:

• To evaluate the histopathological effects of HYA and PRP injections into the vocal cords of New Zealand rabbits.
• To compare the efficacy and safety of HYA and PRP as vocal cord injection materials.

Main Methods:

• PRP was injected into the right vocal cords of 12 rabbits (PRP group).
• HYA was injected into the left vocal cords of 6 rabbits (HYA group).
• The left vocal cords of the remaining 6 rabbits served as controls.
• Histomorphological assessments were performed after two months, evaluating parameters like inflammation, atrophy, necrosis, neovascularization, fibrosis, and foreign body reaction.

Main Results:

• No significant differences were observed in chronic inflammation, mucosal atrophy, necrosis, foreign body reaction, or muscular atrophy among the groups.
• A statistically significant increase in neovascularization was noted in both the HYA and PRP groups compared to the control group (p<0.05).
• No significant difference in fibrosis was found between groups. HYA was detected in 2/6 vocal cords after two months, while PRP was not detected in any.

Conclusions:

• Both HYA and PRP are safe for vocal cord injection.
• HYA is biocompatible and safe, but its short-term effectiveness is suggested by its limited presence after two months.
• PRP is also short-term effective, inexpensive, readily available, and inert, making it suitable for testing purposes before long-term material application.