Effect of a Single Injection of Basic Fibroblast Growth Factor into the Vocal Folds: A 36-Month Clinical Study

Prospective Outcomes After Serial Platelet-Rich Plasma (PRP) Injection in Vocal Fold Scar and Sulcus

OBJECTIVE

Vocal fold scar and sulcus pose significant treatment challenges with no current optimal treatment. Platelet-rich plasma (PRP), an autologous concentration of growth factors, holds promise for regenerating the superficial lamina propria. This study aims to evaluate the potential benefits of serial PRP injections on mucosal wave restoration and vocal function.

METHODS

In a prospective clinical trial across two institutions, patients with vocal fold scar underwent four serial PRP injections, one month apart. Blinded independent laryngologists and expert listeners used pretreatment and one-month post-fourth injection videostroboscopy and CAPE-V assessments to evaluate mucosal wave and voice quality changes, respectively. Additionally, patient reported outcome measures (PROMs) were evaluated.

RESULTS

In the study, 15 patients received 55 PRP injections without adverse effects. Eight patients (53.3%) had mild, three patients (20%) had moderate, and four patients (26.7%) had severe scar. There was an average reduction of 8.7 points in post-treatment VHI-10 scores (p = 0.007). The raters observed an improvement in post-treatment voice in 73.4% of cases, and CAPE-V scores showed a reduction of 18.8 points on average (p = 0.036). The videostroboscopic VALI ratings showed an improvement in mucosal wave rating from 2.0 to 4.0. On average, the raters perceived the post-PRP exams to be better in 56.7% of cases.

CONCLUSIONS

PRP has been validated as a safe autologous option for treatment of vocal fold scar. While results for mucosal wave and voice quality varied, there was a consistent improvement in PROMs.

LEVEL OF EVIDENCE

Level 3: Prospective cohort study, with blinded analysis Laryngoscope, 2024.

Long-term outcomes of bilateral medialisation thyroplasty in patients with vocal fold atrophy with or without sulcus

OBJECTIVE

Evaluate long-term voice outcome after bilateral medialisation thyroplasty in glottic insufficiency due to vocal fold atrophy with or without sulcus.

METHODS

Patients after medialisation thyroplasty for vocal fold atrophy with or without sulcus were identified. Long-term post-operative subjective voice outcomes (> 1 year) using Voice Handicap Index-30, subjective ratings on voice aspects and study-specific questionnaire were compared to pre-operative and shorter-term (1 year) values.

RESULTS

Thirty-six patients were identified, of which 26 were included (16 atrophy, 10 sulcus) with median follow up of 6.7 years. Mean Voice Handicap Index score at > 1 year (40.0) showed clinically relevant (≥ 15 for groups) and statistically significant improvement compared to pre-operative score (58.1) and remained stable compared to post-operative score (35.7) at one year. Ten patients (56 per cent) reported clinically relevant improvement (≥ 10) after more than five years.

CONCLUSION

Long-term improvement in subjective voice outcomes is attainable in a significant proportion of patients undergoing bilateral medialisation thyroplasty for atrophy with or without sulcus.

The use of basic fibroblast growth factor to improve vocal function: A systematic review and meta-analysis

OBJECTIVES

This systematic review and meta-analysis examines if intralaryngeal injection of basic fibroblast growth factor 2 (FGF2) can improve voice outcomes in those with vocal disability.

DESIGN

A Systematic review of original human studies reporting voice outcomes following intra-laryngeal injection of basic fibroblast growth factor 2 in those with vocal dysfunction. Databases searched were Medline (1946-July 2022), Embase (1947-July 2022), Cochrane database and Google Scholar.

SETTING

Secondary or tertiary care centres that undertook the management of voice pathology Hospital.

PARTICIPANTS

Inclusion criteria were original human studies reporting voice outcome measurements following intralaryngeal injection of FGF2 to treat vocal fold atrophy, vocal fold scarring, vocal fold sulcus or vocal fold palsy. Articles not written in English, studies that did not include human subjects and studies where voice outcome measures were not recorded before and after FGF2 injection were excluded from the review.

MAIN OUTCOME MEASURES

The primary outcome measure was maximum phonation time. Secondary outcome measures included acoustic analysis, glottic closure, mucosal wave formation, voice handicap index and GRBAS scale.

RESULTS

Fourteen articles were included out of a search of 1023 and one article was included from scanning reference lists. All studies had a single arm design without control groups. Conditions treated were vocal fold atrophy (n = 186), vocal cord paralysis (n = 74), vocal fold fibrosis (n = 74) and vocal fold sulcus (n = 56). A meta-analysis of six articles reporting on the use of FGF2 in patients with vocal fold atrophy showed a significant increase of mean maximum phonation time of 5.2 s (95% CI: 3.4-7.0) at 3-6 months following injection. A significant improvement in maximum phonation time, voice handicap index and glottic closure was found following injection in most studies assessed. No major adverse events were reported following injection.

CONCLUSIONS

To date, intralaryngeal injection of basic FGF2 appears to be safe and it may be able to improve voice outcomes in those with vocal dysfunction, especially vocal fold atrophy. Randomised controlled trials are needed to further evaluate efficacy and support the wider use of this therapy.

Evaluation of Safety After Intracordal Basic Fibroblast Growth Factor Injection

OBJECTIVES

Although there are many reports of voice improvement with intracordal trafermin (a basic fibroblast growth factor) injections under local anesthesia, few papers have documented the safety of trafermin. Therefore, we aimed to investigate whether trafermin is safer than control drugs (triamcinolone acetonide) early after intracordal injection under local anesthesia.

METHODS

We conducted a retrospective review from the medical records of patients who underwent intracordal injection with trafermin and triamcinolone acetonide under local anesthesia at our institution. Early postinjective complications were defined as changes in vital signs and chief complaints early after intracordal injection.

RESULTS

A total of 699 and 297 patients underwent intracordal injection under local anesthesia with trafermin and triamcinolone acetonide, respectively. Of these, 227 and 130 patients had early postinjective complications with trafermin and triamcinolone acetonide, retrospectively. The most common complications occurring with trafermin was increased blood pressure in 39 cases (5.58%): 17 cases (2.43%) of blood pressure increase of ≥20 mm Hg. Other complications included pharyngeal discomfort in 37 (5.29%), lightheadedness in 33 (4.72%), and phlegm discharge in 29 (4.15%). Triamcinolone acetonide caused pharyngeal discomfort in 28 patients (9.43%), phlegm discharge in 17 patients (5.72%), lightheadedness in 12 patients (4.04%), sore throat in 11 patients (3.70%), increased blood pressure in 10 patients (3.37%): 7 cases (2.36%) of blood pressure increase of ≥20 mm Hg, and dizziness in seven patients (2.36%). Statistical analysis of the complications between trafermin and triamcinolone acetonide showed no significant differences.

CONCLUSIONS

The proportion of early postinjective complications from intracordal injection of trafermin is no significant difference in that of triamcinolone acetonide. The results suggest that the early postinjective complications are not due to the drug action of trafermin, but rather to complications from the intracordal injection procedures. Intracordal trafermin injection may be safe in the short term.

Changes in serum basic fibroblast growth factor concentration following intracordal injection

Objective

Although many studies have reported improvements in voice outcomes with intracordal trafermin injection, there is a lack of data documenting its changes in serum basic fibroblast growth factor (bFGF) blood concentration. This study examined whether serum bFGF concentrations change after intracordal trafermin injection.

Methods

This retrospective study was conducted at Tokyo Voice Center. We investigated serum bFGF concentrations before and after injection in 40 patients who underwent intracordal trafermin injection. There were 26 males and 14 females, with an age ranging from 13 to 88 years (average 53.25 years). They were diagnosed with paralysis (15 patients), atrophy (15 patients), sulcus (8 patients), and others (2 patients: scar and functional), presenting with severe hoarseness that interfered with daily life.

Results

The mean pre- and post-injective serum bFGF concentration of the 40 patients was 6.689 and 4.658 pg/mL, respectively. The difference in mean serum bFGF concentration between pre- and post-injective was -2.031 pg/mL. The Pearson correlation coefficient was calculated to evaluate the correlation between dosage of trafermin and post-injective serum bFGF concentration, and a moderate correlation was found at r = 0.52. Generalized linear model regression analysis was performed for the purpose of adjusting for confounding among variables. The only variable that showed a statistically predominant association with post-injective serum bFGF concentrations was the dosage of trafermin, with an estimated regression coefficient of 0.048.

Conclusion

In this study, the dosage of trafermin we injected and post-injective serum bFGF concentrations were dose-dependent but the amount of changes in the serum bFGF concentration was negligible within the physiological range. Therefore, as with subcutaneous and wound administration, intracordal trafermin injections may be safe.

Level of Evidence

Level IV.