Voice and Swallowing Outcomes after Vocal Fold Medialization in Patients with Unilateral Vocal Fold Paralysis

Abstract

Background

Unilateral vocal fold paralysis (UVFP) is a common condition that may have varying economical and personal consequences for those afflicted by it. Patients often have dysphonia as a primary concern and may also experience aspiration in certain cases. This research aimed to assess the voice and swallowing results after injection laryngoplasty and medialization thyroplasty in patients with UVFP.

Methods

This prospective study was carried out on 20 consecutive patients suffering from moderate to severe dysphonia with or without aspiration, with ages ranging from 22 to 61 years old, with clinical criteria of UVFP with glottic gap approximately ≥ 2 mm not responding to voice therapy at least 6 months after the onset of paralysis.

Results

All patient showed improvement in their symptoms evaluated by objective (acoustic and aerodynamic), subjective (GRBAS scale and VHI 10) voice assessment and swallowing parameters. MT showed significant improvement when compared to injection laryngoplasty (IL) at 3 months post-operative in contrast to nearly similar outcome at 2 weeks post-operative.

Conclusions

Significant short-term improvements in dysphonia and aspiration were obtained with medialization thyroplasty and injection laryngoplasty. Patients with mild to moderate gaps who complained of dysphonia alone preferred to start with injection, while patients with moderate to large gaps who complained of dysphonia + aspiration preferred MT (±)AA. Even at short time evaluation, medialization thyroplasty is superior to IL for patients with aspiration.

Introduction

Unilateral vocal fold paralysis (UVFP) is a common illness that may have various effects on individuals’ quality of life. Patients often have dysphonia as their main concern and may sometimes have issues with aspiration. The most frequent causes often occur after surgical trauma (thyroidectomy), as well as cases of unknown origin (idiopathic). Symptoms of UVFP is treated by various techniques including injection laryngoplasty, medialization laryngoplasty (ML) with or without arytenoid adduction (AA) [1].

Isshiki et al. and Neterville have made more progress in the field of (AA) This technique has been especially effective in cases where there is a significant posterior glottic gap and/or a high vagal lesion involving the superior (SLN) and recurrent laryngeal nerve (RLN), or when there is a difference in level [2–4].

Various materials, such as carved sialastic, Gore-Tex, prefabricated commercial sialastic implants, hydroxyapatite, and titanium, have been used for medializing the vocal folds.

On the other hand, hyaluronic acid (HA), collagen, methylcellulose, calcium hydroxyapatite and fat have been used in injection laryngoplasty [5–9].

The purpose of this research is to assess the voice and swallowing abilities of patients with unilateral vocal cord paralysis after undergoing injection laryngoplasty, medialization thyroplasty, with or without AA, using both subjective and objective measures.

Materials and Methods

This prospective nonrandomized study included 20 consecutive patients, 7 males and 13 females with their ages ranging from 22 to 61 years old, all patients had glottic gap approximately ≥ 2 mm and suffered from moderate to severe symptoms including dysphonia and sometimes aspiration at least 6 months after the onset of paralysis with trial of voice therapy was done.

The research was conducted under clearance from the Ethical Committee of Tanta University Hospitals, Egypt, with the assigned (approval code: 35405/4/22). A well-informed written permission was acquired from either the patient or the patient’s family.

Exclusion criteria: unfit for surgery including (bleeding disorder, compromised immune status and multiple comorbidities, upper aero digestive tract malignancy either under treatment or not cured, poor chest condition as COPD).

Patients were divided into two groups: Group A (injection laryngoplasty) included 30% males and 70% females with ages ranging from 27 to 65 years old, while Group B (medialization laryngoplasty) included 40% males and 60% females with ages ranging from 22 to 61 years old.

Local Examination

Endoscopic examination involves rigid 6 mm 70 degree and flexible naso-laryngoscopy.

Voice Assessment

1. Perceptual voice analysis (GRBAS) including five grades from normal to severe. (G) Overall Grade, (R) Roughness, (B) Breathiness, (A) Asthenic, and (S) Strained.

2. Acoustic measures such as jitter, shimmer, and noise-to-harmonic ratio (NHR) provide an objective evaluation of the patient’s voice quality.

3. Maximum phonation time (MPT) is used as quantitative measures of aerodynamic performance. The MPT is considered normal when it is more than 10 s, mild decrease when it is 8 to 10 s, moderate when it is between 5 and 7 s, and severe when it is less than 5 s.

4. The voice handicap index (VHI): modified Arabic form of VHI10 using Egyptian accent [10].

Swallowing Evaluation (FEES)

A fibre-optic endoscopic evaluation of swallowing (FEES) [11].

Analysis

variations from the normal anatomy and physiology, Endo laryngeal sensation can also be assessed, bolus flow during swallow, bolus holding, laryngeal aspiration and penetration [8-Point Penetration- Aspiration scale (PAS)], and post-swallow residue should be documented [12].

Contraindications

drowsy or unable to cooperate patients, history of bronchospasm or laryngospasm, vasovagal response, cardiac instability, severe epistaxis or a physical obstruction to the passing of the scope. Adverse reactions to the topical anaesthetic are rare, but clinicians should take an adequate case history, adhere to recommended doses and have resuscitation measures available.

In our study, 2 patients in IL group and 5 patients in MT group were complaining of dysphonia and mild aspiration to fluids while 3 patients in medialization group were complaining of Severe dysphonia and aspiration with mild dysphagia.

Office Based Vocal Fold Injection

The injectable material used in our study when attempting local vocal fold injection was HA 2% which is approved by the Egyptian ministry of health to be used for intraocular or intralaryngeal injection. At first local xylocaine pump spray 4% was to numb the mucous membranes of the oropharynx and larynx, then an injection of 2 cc of lidocaine HCL 2% was administered into the subcutaneous tissue at the mid portion of cricothyroid membrane. Patients are carefully observed for a short period of time immediately after VFI to identify any possible complication. Figure 1.

Fig. 1.

A: Local vocal cord injection, using the trans-cervical approach via cricothyroid membrane and B: pre injection glottic gap. C: injection continued and observed by flexible laryngoscope help in confirming the needle site and observing the injection results

Injection Laryngoplasty Under General Anaesthesia

When the patient could not tolerate or refused local anaesthesia, the general anaesthesia was used. We used HA 2% in three patients and paraumbilical processed fat was used in two patients, the fat was collected by plastic fat transfer suction cannula and processed by micro fat filter.

All patients underwent evaluation using the assessment procedures mentioned above at two weeks and three months following the injection to measure the treatment’s progress. Figure 2.

Fig. 2.

A: The collected fat is prepared using fat transfer microfilter to filter blood, serum, and fatty acids B: Direct laryngoscopy used for transoral vocal fold injection lateral to the left thyroarytenoid muscle, the needle is inserted close to the inner thyroid perichondrium

Medialization Thyroplasty Technique

The procedure was performed under local anaesthesia by the same surgeon. This procedure needs the patient’s cooperation at certain intervals throughout the process. A small incision in skin crease roughly at mid thyroid cartilage level from 1 cm paramedian on the unaffected side to 1 cm lateral from posterior margin of thyroid cartilage on the affected side. Retractors are used to retract the strap muscles. The thyroplasty window is created with important aspects (1) the anterior incision is set back at least 5 mm from the midline, (2) the window is centred on the lower half of the thyroid cartilage to avoid medialization of the false vocal folds. During the medialization, the surgeon decides the implant size inserted by acoustic feed-back by asking the patient to produce a voice with appropriate pitch, devoid of strained or breathy voice and by visual feedback from monitoring by flexible laryngoscopy. We used routinely a thin sheet of Gore-Tex used in vascular surgery and we preserved the cartilage of the window to avoid migration of the implant and if it is loose or broken, we shift to carved sialastic block to secure the implant in place which occurred in three patients. Figure 3.

Fig. 3.

(A) Strap muscle retraction showing thyroid cartilage. (B) A window created on the lower half of thyroid cartilage. (C) window landmarks (D) A thin sheet of Gore-Tex is gradually layered through the window

Statistical Analysis

The statistical analysis was conducted using SPSS v26 software (IBM Inc., Chicago, IL, USA). The quantitative variables were expressed as the mean and standard deviation (SD) and compared between the two groups using an unpaired Student’s t-test.

Results

Our study included 20 patients, 7 males and 13 females, with ages ranging from 22 to 61 years old (44.45 ± 12.65 years). Group A included 30% males and 70% females, with ages ranging from 27 to 65 years old (Mean ± SD 43.60 ± 13.02 years), while Group B included 40% males and 60% females, with ages ranging from 22 to 61 years old (Mean ± SD 45.30 ± 12.29 years).

Eight patients were injected with HA (5 under local anesthesia and 3 under general anesthesia) while the remaining two patients were injected with filtered fat. We used carved sialastic block in 3 patients and Gore-Tex sheet in 7 patients. Table 1.

Table 1.

Materials used in medialization

		Group A (n = 10)	Group B (n = 10)
Material used	H. A	8 (80%)	0%
	Autologous fat	2 (20%)	0%
	Gore-Tex sheet	0%	7 (70%)
	Carved silastic block	0%	3 (30%)

2 patients underwent MT + AA (patients with very wide gap and malpositioned arytenoid, 6 patients underwent previous injection in medialization group according to patient’s preference despite wide gap. Table 2.

Table 2.

Distribution of the studied cases according to previous Surgery, type of surgery, aspiration pneumonia in medialization thyroplasty

Previous Surgery (n = 10)
No	4 (40.0%)
Previous hyaluronic acid injection	4 (40.0%)
Multiple hyaluronic acid injections	1 (10.0%)
Previous radiesse	1 (10.0%)
Type of surgery ( n  = 10)
MT	8 (80%)
Medialization + AA	2 (20%)

Data are presented as number (%)

Etiology of UVFP in our study has been found to be 40% after thyroidectomy, 20% idiopathic, 10% after excision of vagal schwannoma, 5% following trauma, 5% cured bronchogenic carcinoma, 5% following COVID-19, and 5% after cervical spine surgery. Table 3.

Table 3.

Distribution of the studied cases according to etiology of UVFP in each group

Etiology	Total (n = 20)	Injection (n = 10)	Medialization (n = 10)
Post-thyroidectomy	8 (40%)	5 (50%)	3 (30%)
Idiopathic	4 (20%)	3 (30%)	1 (10%)
Post central lesion	2 (10%)	0 (0%)	2 (20%)
Post vagal schwannoma	2 (10%)	0 (0%)	2 (20%)
Post covid-19 infection	1 (5%)	1 (10%)	0 (0%)
After neck trauma	1 (5%)	0 (0%)	1 (10%)
Post cervical spine surgery	1 (5%)	0 (0%)	1 (10%)
Bronchogenic carcinoma	1 (5%)	1 (10%)	0 (0%)

Data are presented as number (%)

Comparison between the two groups according to (glottic gap, VHI10, MPT), pre-treatment vs. post-treatment at 2 weeks and 3 months. Medialization thyroplasty showed significant improvement when compared to injection laryngoplasty (IL) at 3 months post-operative and more, in contrast to nearly similar outcome in both groups at 2 weeks post-operative as showed in Table 4.

Table 4.

Comparison between the two studied groups according to (glottic gap, VHI10, MPT) preoperatively, 2 weeks and 3 months postoperatively

		Group A ( n  = 10)
		Pre-operative	After 2 weeks	After 3 months
Glottic gap (mm)		2.10 ± 0.21	0.50 ± 0.33	1.30 ± 0.82
p1			0.010*	0.264
		Group B ( n  = 10)
		Pre-operative	After 2 weeks	After 3 months
Glottic gap (mm)		3.25 ± 0.54	0.20 ± 0.42	0.55 ± 0.44
p2			< 0.001	0.005*
p3			0.075	0.035*
VHI10
Group A ( n  = 10)
VHI10	Pre-operative		After 2weeks	After 3 months
	23.40 ± 3.24		12.30 ± 4.08	11.80 ± 4.44
p1			0.001*	< 0.003*
Group B ( n  = 10)
	Pre-operative		After 2 weeks	After 3 months
VHI10	19.30 ± 11.23		13.0 ± 8.08	5.40 ± 5.46
p2			0.025 *	0.00*
p3			0.684	0.02 *
MPT
Group A ( n  = 10)
	Pre-operative		After 2weeks	After 3 months
MPT	5.25 ± 1.12		8.65 ± 1.71	8.37 ± 2.12
p1			< 0.001*	0.003*
Group B ( n  = 10)
	Pre-operative		After 2 weeks	After 3 months
MPT	4.10 ± 0.81		7.61 ± 1.26	10.30 ± 0.97
p2			0.025*	< 0.001*
p3			0.143	0.011*

P1: p value compared to pre-operative in group A, P2: P compared to pre- operative in group B, P3: P between group A and group B. *: Statistically significant at p ≤ 0.05

Regarding the GRBAS scale analysis among group A (injection), the overall grade of dysphonia (G) showed stationary improvement results along the three months of the follow-up, while B (breathiness), A (asthenia) showed initial significant improvement at two weeks then got slight worsening again at three months, while R (roughness) was slightly improved but not reached significant level. On the other hand, all values in group B (medialization) showed significant improvement at two weeks, and the improvements continued at three months and beyond except for straining which showed no improvement. Table 5.

Table 5.

Comparison between the two studied groups according to GRBAS scale

GRBAS scale
Overall grade of dysphonia (G)
	Group A	Group B	p  value
Preoperative evaluation	2.50 ± 0.53	2.40 ± 0.52	0.739
2 weeks post-operative	1.30 ± 0.48	1.40 ± 0.52	0.739
3 months post-operative	1.30 ± 0.82	0.70 ± 0.82	0.001*
Roughness of voice (R)
Preoperative evaluation	1.60 ± 0.70	1.10 ± 0.32	0.123
2 weeks post-operative	1.30 ± 0.48	1.0 ± 0.0	0.280
3 months post-operative	0.90 ± 0.74	0.80 ± 0.42	0.853
Breathiness of voice (B)
Preoperative evaluation	1.60 ± 1.17	2.50 ± 0.53	0.089
2 weeks post-operative	0.70 ± 0.48	0.40 ± 0.70	0.218
3 months post-operative	1.20 ± 0.79	0.30 ± 0.48	0.019 *
Asthenic voice (A)
Preoperative evaluation	0.80 ± 1.03	0.80 ± 0.79	0.912
2 weeks post-operative	0.40 ± 0.52	0.20 ± 0.42	0.481
3 months post-operative	0.50 ± 0.71	0.10 ± 0.32	0.247
Strained voice (S)
Preoperative evaluation	0.0 ± 0.0	0.10 ± 0.32	0.739
2 weeks post-operative	0.80 ± 0.63	0.70 ± 0.48	0.796
3 months post-operative	0.0 ± 0.0	0.20 ± 0.42	0.481

Data are presented as Mean ± SD, *: Statistically significant at p ≤ 0.05

Regarding acoustic parameters (Jitter, Shimmer, and NHR), only jitter showed significant improvement at 3 months after MT (p value = 0.015). Moreover, postoperative shimmer and NHR improved but without statistical significance differences at 2 weeks, 3 months (p value 1.000, 0.173), (p value 0.105, 0.426) respectively, that led to improvement of acoustic parameters without significant difference between the two studied groups. Therefore, acoustic parameters are not recommended in voice assessment.

Evaluation of swallowing was done by FEES for patients with any degree of aspiration by using aspiration penetration scale. two patients (20%) complain of dysphonia with mild aspiration to fluids. While in medialization group, two patients (20%) complain of dysphonia, five patients (50%) dysphonia with mild aspiration, and three patients (30%) complain of severe dysphonia with aspiration with dysphagia. In the medialization group, there was a significant improvement in aspiration at 2 weeks and 3 months postoperative (p2 = 0.034 & 0.025). On the other hand, there was no significant improvement with (p = 0.135) in the injection group due to the relative mild symptoms preoperative. Table 6.

Table 6.

Comparison between the two studied group according to complaints

Complaint	Injection (n = 10)	Medialization (n = 10)
Dysphonia	8 (80.0%)	2 (20.0%)
Dysphonia and mild aspiration to fluids	2 (20.0%)	5 (50.0%)
Severe dysphonia and aspiration with mild dysphagia	0 (0.0%)	3 (30.0%)

Data are presented as number (%)

Discussion

Unilateral Vocal fold paralysis represent one of the common laryngeal morbidities that affects the patient’s life extremely when not compensated. In our study we compared the short-term voice and to lesser extent swallowing outcome in patients with chronic UVFP presenting with moderate to severe symptoms.

Regarding the injection by HA or fat, both techniques showed temporary improvement for few months which decreased again as the short acting materials is slightly absorbed over time and mostly disappear after 6 months. In our study we did not use slightly longer time substances like Calcium Hydroxyapatite (CAHA- Radiesse) which last for about 18 months as the health insurance in our area couldn’t afford its cost. However, fat is considered as Permanent material with a variable duration due to absorption. We have study showed that fat injection laryngoplasty is of the same efficacy as HA and due to shortage of materials, some patients can’t afford the cost of injectable material, we used fat injection [13].

In our study we detected significant improvements in the mean MPT among IL patients at 2 weeks (8.65 s) and at 3 months (that decreased to 8.37 s) postoperative when compared to pre-treatment measurement (5.25 s) (p value < 0.001*, p value 0.003* respectively).

Conversely, the average duration before surgery for the MT group was 4.1 s, whereas it improved to 10.3 s three months after the operation. The observed difference was statistically significant (p value < 0.001). In the long term follow up MT seems to show stable and better outcome.

When comparing both groups to each other there was no significant difference at 2 weeks’ period. But there was statistically significant difference at 3 months’ period (p3 < 0.011) for MT group. This concurs with Tsai et el [14]., Lundy et al. [15], Dworkin et al. [16]. In contrast to, Umeno et el [17]. who showed that a significant increase in MPT after both MT and IL.

Benninger et al. [18] stated that Objective voice tests and video-endoscopic measures are insufficient for evaluating the extent of handicapping experienced by a patient due to their voice problem that’s why we used multiple methods for evaluation of the voice.

Malki et al. reported that the Arabic VHI questionnaire was effectively administered to the Arabic-speaking community, since it enabled patients to accurately assess the extent of their voice-related issues.

The patients in the present study experienced notable enhancement in their subjective vocal quality during the initial follow-up (after 2 weeks), which persisted for up to 3 months as observed during the subsequent follow-up in the medialization group. However, among the injection group, four patients expressed late dissatisfaction (at three months and more) also they experienced vocal impairment, with two of them scheduled for reinjection. These patients affected our result that made comparison between the 2 groups showed significant difference at 3 months (p value 0.023). Cantillo-Banos et el [19]., Hartl et al. [20] reported that there was an improvement in VHI scores without significant difference between the two studied groups.

Not every patient in the Morgan et al. [21] study had a VHI evaluation. only six patients in the injection group and three patients in medialization group.

By reviewing the literature regarding the swallowing evaluation by FEES, most studies didn’t evaluate swallowing [17, 19, 22, 23]. This encouraged us to do a simple routine and rapid evaluation of swallowing by FEES for the included patients.

Lundy et al. [15] found that, patients in the IL group who had transcervical injections with fibreoptic guidance in an outpatient setting, showed significant improvement in all metrics from pre-treatment to 1-month after therapy, which seems to be a very short time to evaluate the improvement even if we used a temporary short term material that is why we considered the minimum follow-up in our study to be three months.

Morgan et al. [21] made a retrospective evaluation on 19 patients with UVFP, which revealed that both injection and medialization laryngoplasty resulted in a comparable improvement in the three voice outcomes that were assessed (VHI 30, SRI, and GRBAS scale). The post-treatment assessments were conducted at varying intervals between 1 and 9 months, and not all patients were assessed simultaneously.

In our study, we evaluated the voice via many subjective and objective parameters to decrease the bias of the evaluation, although we had a somewhat shorter follow-up time. Furthermore, our research anticipated that MT could produce very long-term improvements in voice characteristics, as evidenced by subsequent follow-up.

Wang CC et al. [15]. conducted A comprehensive review and meta-analysis to assess the efficacy of HA IL as a therapy for individuals with UVFP. The findings indicated that HA IL has the potential to enhance patients’ glottal closure, extend maximum phonation time, improve perceptual assessments of voice quality, and enhance overall quality of life. However, the duration of these therapeutic effects differed across various investigations, but generally the effect is short for few months.

Regarding the acoustic parameters (jitter, shimmer, and NHR), medialization group showed statistically significant reduction in jitter value only, so it seems to be not highly recommended in voice assessment of patients with unilateral vocal fold paralysis.

Swallowing also was assessed by FEES through flexible fibreoptic laryngoscopy with methylene blue liquid swallow. There was no statistically significant difference among injection group unlike the medialization group.

In our hospital, we used to treat UVFP with cut silastic blocks. However, with time, we discovered that it is harder to manipulate and difficult to do fine adjustment of patient’s voice quality, while the vascular Gore-Tex sheet is easy to manipulate and to adjust, moreover it can be removed easily and readjusted either during the procedure or later on, however it carries more risk of migration.

While the vascular Gore-Tex sheet is easy to manipulate and adjust, it can also be easily removed and readjusted either during the procedure or later on. However, it carries a higher risk of migration. In recent years we tried to overcome the migration risk of the Gore-Tex sheet by using a trap door technique and by fixing the cartilage window at the end, and we kept the carved sialastic block for the condition when the cartilage window is broken.

Our study had limitations as a small sample size with a relatively short duration of follow-up. Therefore, we recommend conducting further studies with a larger patient group and a long-term follow-up to provide more support for the outcomes and complication rates of both techniques. Additionally, the duration of vocal fold paralysis should be taken into consideration when making decisions.

Conclusions

Significant short-term improvements in dysphonia and aspiration were obtained with medialization thyroplasty and injection laryngoplasty. Patients with mild to moderate gaps who complained of dysphonia alone preferred to start with injection, while patients with moderate to large gaps who complained of dysphonia + aspiration preferred MT(±) AA. Even at short time evaluation, medialization thyroplasty is superior to IL for patients with aspiration.

Author Contributions

All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by [Mahmoud Hamouda], [Kamal Ebeid] and [Mohamed Elsayed Darwish]. The first draft of the manuscript was written by [Emad Mohammed Shehata] and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.

Funding

No funding was received for conducting this study.

Data Materials and/or Code Availability

Data is available upon reasonable request from corresponding author.

Declarations

Conflict of Interest

The authors have no financial or proprietary interests in any material discussed in this article.

Ethical Approval

The research was conducted under clearance from the Ethical Committee of Tanta University Hospitals, Egypt, with the assigned (approval code: 35405/4/22).

Consent

A well-informed written permission was acquired from either the patient or the patient’s family.