In Vitro Evaluation of Biomaterials for Vocal Fold Injection: A Systematic Review

Vocal fold injection is a preferred treatment in glottic insufficiency because it is relatively quick and cost-saving. However, researchers have yet to discover the ideal biomaterial with properties suitable for human vocal fold application. The current systematic review employing PRISMA guidelines summarizes and discusses the available evidence related to outcome measures used to characterize novel biomaterials in the development phase. The literature search of related articles published within January 2010 to March 2021 was conducted using Scopus, Web of Science (WoS), Google Scholar and PubMed databases. The search identified 6240 potentially relevant records, which were screened and appraised to include 15 relevant articles based on the inclusion and exclusion criteria. The current study highlights that the characterization methods were inconsistent throughout the different studies. While rheologic outcome measures (viscosity, elasticity and shear) were most widely utilized, there appear to be no target or reference values. Outcome measures such as cellular response and biodegradation should be prioritized as they could mitigate the clinical drawbacks of currently available biomaterials. The review suggests future studies to prioritize characterization of the viscoelasticity (to improve voice outcomes), inflammatory response (to reduce side effects) and biodegradation (to improve longevity) profiles of newly developed biomaterials.

Dysphagia Severity and Outcomes Following Iatrogenic High Vagal Nerve Injury

Objective: To examine severity of dysphagia and outcomes following iatrogenic high vagal nerve injury. Methods: Retrospective chart review of all patients with iatrogenic high vagal nerve injury that were seen at a tertiary referral center from 2012 to 2020. Results: Of 1304 patients who met criteria for initial screening, 18 met all inclusion criteria. All 18 required intervention to address postoperative dysphagia. Eleven required enteral feeding tubes with 7 eventually able to advance to exclusively per oral diets. Fourteen underwent vocal fold injection and 6 underwent laryngeal framework surgery. Sixteen pursued swallowing therapy with speech language pathology. Patients lost a mean of 8.6 kg of weight in the 6 months following the injury. Swallowing function on the Functional Outcome Swallowing Scale (FOSS) and Functional Oral Intake Scale (FOIS) was 4.4 and 2.4 respectively immediately following the injury and improved to 1.9 and 5.3 at the last follow-up. No patients had complete return of normal swallowing function at last follow up. Conclusion: Iatrogenic high vagal injury causes significant lasting dysphagia which improves with intervention but does not completely resolve. Interventions such as vocal fold injection, medialization laryngoplasty, cricopharyngeal myotomy, or swallowing therapy may be required to reestablish safe swallowing in these patients.

Vocal Fold Injection Augmentation for Post-Airway Reconstruction Dysphonia: A Case Series

Objectives: Post airway reconstruction dysphonia (PARD) is common and has a significant effect on the quality of life of patients. Vocal fold injection augmentation (VFIA) is one treatment that can be used to improve glottic insufficiency in some patients. The goal of this study was to characterize the use and outcomes of VFIA for PARD. Methods: Retrospective chart review from January 2007 to July 2018 at a tertiary pediatric care center. Consecutive patients with PARD who underwent VFIA, who had a preoperative voice evaluation and a follow-up evaluation within 3 months after VFIA (fat, carboxymethylcellulose gel, hyaluronic acid). Results: Thirty-four patients (20 female) underwent VFIA. The mean age at the time of the injection was 13.6 years (SD 6.1). Twenty patients (58.8%) had a history of prematurity and a mean of 1.8 open airway surgeries. After injection, 29/34 patients (85.3%) noted a subjective voice improvement. The baseline Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V) overall severity score decreased by a mean of 5.7 (SD = 19.6) points, P = .12. Total pediatric Voice Handicap Index (pVHI) improved by 6.0 (SD = 19.5) points, from 57.4 (SD = 20.0) to 51.4 (SD = 17.2), P = .09. Functional pVHI subscore demonstrated a significant improvement, with a decrease of 3.4 (SD = 7.3) points, P = .02. All procedures were performed as an overnight observation and no complication occurred. Conclusion: Patients with PARD represent a complex subset of patients. VFIA is a straightforward intervention that may improve voice perception. Many patients reported subjective improvement despite minimal objective measurement. Further work is warranted to elucidate the role of injection in management of PARD

Outcomes versus complications in patients undergoing different modalities of injection laryngoplasty

Background Glottal insufficiency results in glottal gap between the two vocal folds, which in turn might cause dysphonia, dysphagia, and breathing problems. Vocal fold injection is considered a safe, reliable, and highly effective method of treatment. The purpose of the present study was to assess voice outcomes and complication rates in patients with glottal insufficiency undergoing injection laryngoplasty (IL) under local versus general anesthesia before, 1 week then 1 month after IL. Results Examined patients were 13 males and 12 females, suffering from dysphonia due to glottal insufficiency with mean age 43.68 ± SD 14.55. Unilateral vocal fold paralysis (UVFP) was diagnosed in seventeen cases, vocal fold scarring in six cases, presbylarynx in one case, and sulcus vocalis in one case. IL was performed in 18 cases under local anesthesia, and 7 under general anesthesia. Hyaluronic acid was injection material in 23 cases and calcium hydroxylapatite in two cases. IL by either local or general anesthesia has improved the patients’ auditory perceptual analysis of voice quality as assessed by “GRBAS” scale and Voice Handicap Index (VHI). There were four (16% of all injections) minor and self-limited complications (12% under local and 4% under general anesthesia). Conclusion Injection laryngoplasty performed under local and general anesthesia offers similar voice outcomes, but with slightly higher self-limited complications in IL under local anesthesia.