Sage Journals: Discover world-class research

Abstract

Objective:

This review set out to examine the applicability of transcutaneous laryngeal ultrasonography (TLUSG) for the assessment of laryngeal function after thyroidectomy.

Methods:

An integrative review of the literature was performed using Medline/PubMed, LILACS, and SciELO databases. The methodological quality of the studies was analyzed using the appraisal tool for cross-sectional studies.

Results:

All 8 included articles investigated laryngeal function with regard to the risk of vocal fold immobility after thyroidectomy. The results regarding the diagnostic power of TLUSG for this assessment are controversial, and there is a tendency to use this examination as a screening procedure for subsequent confirmation by flexible laryngoscopy.

Conclusions:

Transcutaneous laryngeal ultrasonography is a viable, noninvasive, and useful tool to assess laryngeal function after thyroidectomy, but current available evidence suggests that it does not replace flexible laryngoscopy for the diagnosis of vocal fold immobility.

Keywords

ultrasonography ultrasonics thyroidectomy larynx vocal cords

Introduction

Ultrasonography (USG) is a technique in which high-frequency acoustic echoes are reflected inside the human body and converted into graphic signals that, in turn, are electronically decoded on a displayed image that can be recorded and used for immediate or later analysis.¹ Overtime, advancements in USG have allowed more detailed investigations that can be assessed both quantitatively and qualitatively, not only from a morphological point of view but also from a functional one.²

Transcutaneous laryngeal ultrasonography (TLUSG) is a technique that specifically assesses the neck structures.^3

-6 It is considered to have an applicability index of over 90%⁴ and does not expose the patient to radiation.^7,8 According to some studies, TLUSG can be used as an alternative to fiberoptic flexible laryngoscopy⁹ and can provide real-time imaging to examine laryngeal function.^8,10 In this regard, TLUSG has become an alternative to investigate laryngeal sequelae in surgical cases involving the anterior cervical region, such as a thyroidectomy.^3,4,7

Thyroidectomy is the preferred surgery for the treatment of certain thyroid diseases¹¹ and is one of the most frequently performed procedures in the world. Although it is considered a safe procedure, with low morbidity and mortality close to 0%,¹² it can cause laryngeal immobility or vocal fold immobility as iatrogenic factors, which compromise the vocal pattern, impair swallowing, and lead to significant complications in the patient’s quality of life.¹³ It is also evident in the literature that this type of iatrogenesis occurs in 1.8% of cases, 1.4% of which are transient and 0.4% permanent, and in many cases results in dysphonia, dysphagia, and dyspnea.¹⁴

Laryngeal examination using a flexible laryngoscope is still considered the reference standard to assess vocal fold function before and after thyroidectomy.^15,16 By contrast, TLUSG is not invasive, uncomfortable, or painful and has been described by some studies as a viable and reliable examination to assess laryngeal function.^4,17,18 Since the test may be performed in real-eating situations and even at the bedside, TLUSG has also been used for the assessment of some biomechanical swallowing parameters to complement the functional assessment of patients with oropharyngeal dysphagia.^19,20

Although the literature describes TLUSG as an alternative to assess the functional integrity of the larynx, it is still necessary to better understand the situations in which this examination can be effectively included in thyroidectomy clinical routine. Therefore, the aim of this study was to seek scientific evidence for the applicability of TLUSG to assess laryngeal function after thyroidectomy.

Materials and Methods

This integrative literature review utilizing the following steps²¹: (1) preparation of the research question; (2) definition of the descriptors and keywords; (3) selection of articles according to the eligibility criteria; (4) collection, data extraction, reading, and critical analysis of articles; (5) interpretation and discussion of the results; and (6) synthesis of the information and presentation of the review.

Search Strategy

The article search was based on the following research question: “What is the applicability of TLUSG for the assessment of laryngeal function after thyroidectomy?” The Medline/PubMed, LILACS, and SciELO databases were consulted. The articles were obtained by cross-referencing the following search terms: (“ultrasonography” OR “ultrasonics” OR “laryngeal ultrasonography” OR “TLUSG” OR “laryngeal ultrasound” OR “ultrasound” OR “transcutaneous laryngeal ultrasonography”) AND (“thyroidectomy” OR “thyroid-surgery”). The search considered articles published between January 2008 and July 2018 in Portuguese, English, and Spanish.

Eligibility Criteria

Articles were included that addressed TLUSG as a diagnostic tool for laryngeal function in patients undergoing partial or total thyroidectomy. The following publication and study types were excluded: literature reviews, editorials, letters to the editor, and conference proceedings; studies using TLUSG only for the diagnosis of thyroid nodules or therapeutic purposes; animal studies; studies that indicated the use of TLUSG in the methods, but did not describe the examination’s findings in the results; and studies that included patients in the sample who underwent other types of surgery in the neck region.

Data Collection and Analysis Procedures

Initially, 2 reviewers independently conducted a database search and selected articles by reading the title and abstract. Duplicate articles were excluded, and the remainder were read in their entirety. In cases of disagreement, a third reviewer was asked to make a decision. After defining studies that met the eligibility criteria, the following data were extracted to comprise the analysis matrix: author, year of publication, place of origin, study objectives, sample characteristics, methodological procedures (including examinations performed, time of assessment, type and positioning of the transducer used, and blinding of evaluators), and conclusions. The methodological quality of the studies was analyzed by appraisal tool for cross-sectional studies (AXIS), a critical analysis tool used to assess the quality and risk of bias in cross-sectional studies.²² This was followed by analysis and critical discussion of the results, together with a synthesis of the information obtained and presentation of the review in this article.

Results

A total of 2697 articles were initially located. After applying the eligibility filters, the final sample comprised 8 articles. The selection process is shown in Figure 1.

Figure 1.

Article selection flowchart.

The selected studies were analyzed according to the findings presented in the analysis matrix (Table 1). The methodological quality of the studies included in this review is presented in Table 2, according to the AXIS tool criteria.

Table 1.

Summary of Studies Using Transcutaneous Laryngeal Ultrasonography (TLUSG) to Assess Laryngeal Function After Thyroidectomy.

Author, Year, Place	Objectives	Sample	Methodological Procedures	Conclusions
Dubey et al,⁶ 2018, India	To define the ideal diagnostic approach for vocal fold mobility via TLUSG, considering subjective assessment, calculation of vocal fold displacement speed (VFDS) or a combination of both, in addition to comparing TLUSG and flexible laryngoscopy (FL) in patients undergoing thyroidectomy.	100 patients (67 women and 33 men) undergoing thyroidectomy. Mean age 45 (33-54) years.	Preoperative and postoperative TLUSG + laryngoscopy Blinded evaluators 6-13 MHz linear transducer, positioned transversely	TLUSG can reliably assess vocal fold changes, with FL reserved for diagnostic confirmation or in doubtful cases. Preoperatively, subjective assessment of vocal fold mobility using TLUSG is sufficient. However, in cases of high risk of vocal fold injury, VFDS should also be used. Postoperatively, VFDS estimation should be added to the subjective assessment by TLUSG when the findings disagree with the preoperative data.
Kılıç et al,¹⁷ 2018, Turkey	To determine the efficacy of TLUSG in assessing vocal fold functionality in patients undergoing thyroidectomy and to assess whether the examination can be a reliable alternative to direct flexible laryngoscopy (DFL).	325 patients (255 women and 70 men) undergoing thyroidectomy. Mean age 48.2 (18-75) years	Preoperative and postoperative TLUSG + laryngoscopy Evaluators not blinded 6-13 MHz broadband linear transducer, positioned according to the anterior and lateral approaches	The high rates of sensitivity (84%), specificity (93.3%), and accuracy (98%) showed that TLUSG is a reliable diagnostic test to assess vocal fold function in patients undergoing thyroidectomy. However, its efficacy is limited in elderly patients and men due to high rates of nonassessable vocal folds. Therefore, TLUSG seems to be more useful in selected patients, such as young people, women, and those who refuse DFL.
Miguel et al,²³ 2017, Spain	To assess the accuracy of TLUSG for the diagnosis of vocal fold paralysis in the immediate postoperative period following total thyroidectomy.	93 patients (73 women and 20 men) undergoing total thyroidectomy. Age older than 18 years. Does not report the mean age.	Preoperative and postoperative TLUSG + video-laryngostroboscopy (VLS) Blinded evaluators 5-10 MHz linear transducer, positioned in the anterior region; when the vocal folds could not be visualized, the lateral position was used	The high sensitivity (93.3%), specificity (96.1%), and predictive value (positive, 82.3; negative, 98.6) of TLUSG when detecting vocal fold paralysis immediately after total thyroidectomy makes this a viable alternative to VLS and video-laryngoscopy for use in the immediate postoperative period. Although previous training in the technique is required, TLUSG seems to be an accurate, sensitive, noninvasive, and inexpensive procedure to assess vocal fold mobility after total thyroidectomy.
Borel et al,²⁴ 2016, France	To assess the efficiency of TLUSG as an alternative to DFL in the early postoperative screening of vocal fold paralysis after total thyroidectomy.	103 patients (18 women and 85 men) undergoing thyroidectomy. Mean age of 51 years.	Preoperative and postoperative TLUSG + laryngoscopy Blinded evaluators 8 MHz high-frequency linear transducer positioned in the anterior region	Nonvisualization of the vocal folds occurred in 27.2% of cases and was associated with male gender, age, weight, surgery time, postoperative drainage, and thyroid weight. Of these, only male gender and age were found to be independent risk factors. In the group of women younger than 50 years, TLUSG had a sensitivity of 50% and a positive predictive value of 97.4%. The sensitivity (33%) of TLUSG is insufficient for early screening of postoperative vocal fold paralysis following thyroid surgery. The USG diagnosis of vocal fold paralysis should be confirmed with direct laryngoscopy.
Wong et al,²⁵ 2015, South Korea and China	To assess vocal fold movement through TLUSG using passive (silent breathing), active (phonation), and Valsalva maneuvers and comparing the visualization rate and diagnostic accuracy between the 3, and to assess whether performing TLUSG with more maneuvers provides better results.	342 patients undergoing elective thyroidectomy Center 1: 142 (112 women and 30 men) Center 2: 200 (155 women and 45 men) Mean age Center 1: 48 (16-75) years Center 2: 55 (18-89) years	Preoperative and postoperative TLUSG + laryngoscopy Blinded evaluators Transducer not reported but positioned according to the transverse approach	TLUSG can be used as a screening tool associated with the Valsalva maneuver due to its higher specificity and high visualization rate when compared to the results of direct laryngoscopy. The passive maneuver has a greater ability to differentiate between mobile and paralyzed vocal folds (passive: 0.942, active: 0.863, Valsalva: 0.893). TLUSG with more maneuvers did not improve the sensitivity or specificity of the examination.
Wong et al,⁴ 2014, South Korea and China	To prospectively assess the importance of 3 reference points (true vocal folds, false vocal folds, and arytenoids) in postoperative vocal fold assessment and to compare the visualization rate and diagnostic accuracy between examinations with 3 points visualized and those with less than 3 points visualized.	245 patients undergoing elective thyroidectomy with or without a concomitant procedure on the neck. Center 1: 118 (95 women and 23 men) Center 2: 127 (104 women and 23 men) Mean age Center 1: 53 (24-84) years Center 2: 48 (20-82) years	Preoperative and postoperative TLUSG + laryngoscopy Blinded evaluators Linear transducer Center 1: 5-10 MHz Center 2: 3-10 MHz Positioned according to the transverse approach	TLUSG is a noninvasive and reproducible tool with high assessment capacity (>90%) for the evaluation of vocal fold paralysis before and after thyroidectomy. Regardless of which of the 3 reference points is identified, the assessment of passive or active vocal fold movement appears to have similar diagnostic accuracy. Finding all 3 reference points did not improve diagnostic accuracy. The assessment of vestibular fold or arytenoid movement in TLUSG was clinically more relevant in the vocal fold assessment.
Wong et al,¹⁸ 2013, China	To assess the accuracy of TLUSG to assess vocal fold functionality.	204 patients (63 women and 161 men) undergoing elective thyroidectomy. Mean age 52 (20-85) years.	Preoperative and postoperative TLUSG + direct laryngoscopy Blinded evaluators 5-10 MHz linear transducer positioned in the anterior region	Postoperative TLUSG had a sensitivity, specificity, positive predictive value, and negative predictive value of 93.3%, 97.8%, 77.8%, and 99.4%, respectively. Of the 175 patients diagnosed with normal movement of both vocal folds by TLUSG, only 1 (<1%) showed unilateral reduction of vocal fold movement by direct laryngoscopy. TLUSG is a noninvasive tool and is useful to select patients for direct laryngoscopy before and after thyroidectomy.
Dedecjus et al,³ 2010, Poland	To find a noninvasive in vivo method to quantify vocal fold functionality with minimal unpleasant effects.	50 patients (41 women and 9 men) selected for thyroidectomy Does not report the mean age	Doppler ultrasound before surgery and 2 days after	When analyzing the vocal folds separately using Doppler, a decrease in the vocal fold mucosal vibration velocity was observed, which was measured through the acoustic signals generated in Doppler B mode. This result coincides with the laryngoscopic findings.

Abbreviations: DFL, direct flexible laryngoscopy; FL, flexible laryngoscopy; VLS, video-laryngostroboscopy.

Table 2.

Classification of Methodological Quality of the Studies Using the Appraisal Tool for Cross-Sectional Studies (AXIS).^a

AXIS Items	Dubey et al⁶	Kiliç et al¹⁷	Miguel et al²³	Borel, et al²⁴	Wong et al²⁵	Wong et al⁴	Wong et al¹⁸	Dedecjus et al³
Introduction
1. Were the aims/objectives of the study clear?	+	+	+	+	+	+	+	+
Methods
2. Was the study design appropriate for the stated aim(s)?	+	+	+	+	+	+	+	+
3. Was the sample size justified?	−	−	−	−	−	−	−	−
4. Was the target/reference population clearly defined? (Is it clear who the research was about?)	+	+	+	+	+	+	+	+
5. Was the sample frame taken from an appropriate population base so that it closely represented the target/reference population under investigation?	+	+	+	+	+	+	+	+
6. Was the selection process likely to select participants who were representative of the target/reference population under investigation?	+	+	+	+	+	+	+	+
7. Were measures undertaken to address and categorize nonresponders?	−	−	−	−	−	−	−	−
8. Were the risk factor and outcome variables measured appropriate to the aims of the study?	+	+	+	+	+	+	+	+
9. Were the risk factor and outcome variables measured correctly using instruments/measurements that had been trialed, piloted, or published previously?	+	+	+	+	+	+	+	+
10. Is it clear what was used to determined statistical significance and/or precision estimates? (eg, P values, confidence intervals)	+	+	+	+	+	+	+	−
11. Were the methods (including statistical methods) sufficiently described to enable them to be repeated?	+	+	+	?	+	+	+	−
Results
12. Were the basic data adequately described?	+	+	+	+	+	+	+	−
13. Does the response rate raise concerns about nonresponse bias?	−	+	+	+	+	?	+	−
14. If appropriate, was information about nonresponders described?	−	+	+	+	+	−	−	−
15. Were the results internally consistent?	+	+	+	+	+	+	+	+
16. Were the results presented for all the analyses described in the methods?	+	+	+	+	+	+	+	+
Discussion
17. Were the authors’ discussions and conclusions justified by the results?	+	+	+	+	+	+	+	+
18. Were the limitations of the study discussed?	+	+	+	+	+	+	+	+
Others
19. Were there any funding sources or conflicts of interest that may affect the authors’ interpretation of the results?	?	+	+	+	?	?	?	?
20. Was ethical approval or consent of participants attained?	+	+	+	?	+	+	+	+

^a + meets the requirements of the item, − does not meet the requirements of the item, and ? partially meets the requirements of the item or unclear data.

Discussion

This review included 8 studies conducted in Eastern and Western European and Asian countries that involved research using TLUSG to assess laryngeal function after thyroidectomy. Two of these were partnerships between institutions in South Korea and China,^4,25 and 1 was based in China,¹⁸ 1 in Japan, 1 in Turkey,¹⁷ 1 in Spain,²³ 1 in France,²⁴ 1 in Poland,³ and 1 in India.⁶ No studies based on the Americas were found.

With regard to the year of publication, the first article was published in 2010.³ There was 1 article published in 2013,¹⁸ 1 in 2014,⁴ 1 in 2015,²⁵ 1 in 2016,²⁴ 1 in 2017,²³ and 2 in 2018.^6,17 Starting in 2013, publications in this field emerged on an annual basis, which demonstrates the scientific community’s interest in contributing more systematic data on laryngeal function after thyroidectomy to find an alternative method of performing this investigation.

With regard to gender and age, the diagnosis of thyroid diseases is prevalent in females and those with advanced age.²⁶ Therefore, a predominance of female and elderly volunteers was expected in all studies included in this review.

In general, the studies used TLUSG after thyroidectomy to investigate vocal fold mobility with regard to the risk of immobility associated with the surgical procedure. Thyroidectomy is one of the most common surgeries in the world, and recurrent laryngeal nerve (RLN) paralysis is a significant complication²⁷ that has a negative impact on voice, swallowing, and quality of life.^13,28

Most studies compared the results of TLUSG with laryngoscopic assessment using flexible or rigid fiberscopes,^{4,6,17,18,24,25} which was expected because laryngoscopic examination is the reference standard when assessing RLN function and vocal fold mobility before and after thyroidectomy. Only 1 study used videostroboscopy for this purpose.²³

In terms of methodology, blinding attempts to eliminate possible biases that may arise due to the behavioral and psychological aspects involved in human research. In most of the studies included in this review,^{4,6,18,23,24,25} the evaluators were blinded to the results of the examinations, which is a necessary precaution when determining the actual sensitivity and specificity rates required to reliably diagnose vocal fold immobility.

Overall, the methodological quality of the studies included in this review was satisfactory according to the AXIS tool criteria. Items that were not properly covered will require attention in future studies on the subject, especially with regard to the description of sample size calculation and the approach to nonresponders or nonassessed patients. Such information is important to leverage evidence and was omitted in some articles. Even fundamental issues such as the existence of funding sources, conflicts of interest, and the participants’ ethical approval were also unclear in some studies.^{3,4,6,18,24,25}

The transducer type used in the studies was linear, but the bandwidth varied, ranging from approximately 5 to 10 MHz. The most common position was transverse in the anterior or lateral region, but vertical positioning has also been proposed in other studies. Positioning appears to be a variable that should be better studied in TLUSG, given that some researchers²⁹ state that the viewing rate of a lateral vertical procedure is better than that of a middle transverse procedure. The authors argue that the reference points used for the transverse approach are the true vocal folds and that these are more difficult to visualize due to the poor ultrasonic permeability of air. Moreover, the transverse approach uses the viewing of arytenoid cartilage as a reference. Instead of being classified according to the reduction in vocal fold mobility, RLN paralysis or paresis is classified based on fixation of the muscular process of the arytenoid cartilage. The limitation of this procedure is the impossibility of synchronous observation of the right and left vocal fold movements, which increases the examination time and presents greater difficulty in detecting differences in vocal fold movements.²⁹

More studies are needed to further the discussion on the tasks requested during the examination. One study showed that the Valsalva maneuver permitted a better viewing rate and specificity.²⁵ This same study compared this and 2 other maneuvers: a passive maneuver (normal breathing) and an active maneuver ([a] vowel phonation). It was found that TLUSG can be used as a screening tool when using the Valsalva maneuver, which avoids subjecting patients to direct laryngoscopy.²⁵

Two studies^13,18 assessed the accuracy of TLUSG for the diagnosis of vocal fold immobility after total thyroidectomy. De Miguel et al²³ investigated the accuracy in the immediate postoperative period. The examination was performed with the transducer positioned transversally, and a passive maneuver (slow breathing) and active maneuver ([a] vowel phonation) were used. When the vocal folds were not visible, the lateral approach was used. Transcutaneous laryngeal ultrasonography was performed after the surgical procedure in the postanesthetic recovery room. The results showed that TLUSG is a viable option compared to direct laryngoscopy and videostroboscopy, with a sensitivity of 93.3% and specificity of 96.1%, and can be performed in the immediate postoperative period.

Wong et al¹⁸ used the same methodology proposed in the study described above²³ at between 7 and 10 days after thyroidectomy. They found that TLUSG is a noninvasive and useful tool, with a sensitivity of 93.3% and specificity of 97.8% for selecting patients to undergo direct laryngoscopy. The results of these 2 studies showed that TLUSG is feasible and useful, both in the immediate and late postoperative periods, for patients undergoing thyroidectomy.

In contrast, the results of 2 other studies^18,24 showed that TLUSG is insufficient for the definitive diagnosis of vocal fold immobility after thyroidectomy. Borel et al²⁴ assessed the efficiency of this examination as an alternative to direct flexible laryngoscopy in the first or second postoperative day. Due to the relatively poor performance of TLUSG for the diagnosis and assessment of vocal fold paralysis, with a sensitivity of 33%, a specificity of 95%, a positive predictive value of 42%, and a negative predictive value of 89%, the authors reported that diagnosis by TLUSG should always be confirmed by direct flexible laryngoscopy and that it may be useful only as a means of screening for subsequent referral to laryngoscopy.

Another study¹⁸ evaluated the accuracy of TLUSG to assess pre- and post-thyroidectomy vocal fold function. It revealed that when the examination was performed after surgery, it had a sensitivity, specificity, positive predictive value, and negative predictive value of 93.3%, 97.8%, 77.8%, and 99.4%, respectively. Despite the high values, the study has some limitations, such as the low number of patients with vocal fold immobility. The authors suggested that TLUSG should be used as a tool for patient selection before and after thyroidectomy and should not be used as an alternative to direct laryngoscopy.

Only one study³ reported a sensitivity of TLUSG of 100% when comparing the preoperative and postoperative period. The assessment criterion was a 50% reduction in vocal fold displacement velocity between the preoperative and postoperative examination. This method detected all patients with postoperative vocal fold immobility. However, this was a pilot study with a small number of cases, and the authors were unable to clearly define the association between the vocal fold displacement speed values and a diagnosis of vocal fold immobility.

Because the results regarding the diagnostic power of vocal fold immobility by TLUSG are controversial, there is a tendency to consider TLUSG as a screening procedure^18,24,25 for subsequent diagnostic confirmation by direct laryngoscopy, thus avoiding the need for an invasive procedure in cases where it would not be necessary. Laryngoscopy, whether direct or flexible, remains the most specific test to confirm the diagnosis of vocal fold immobility, with a success rate of 99%.²⁴

Some studies indicate that the male gender and advanced age are variables that may interfere with good visualization during the TLUSG examination.^17,24 The different angle in men and calcification of the structures in the elderly patients are factors that limit the performance of the test and that are strongly associated with the number of patients with vocal folds classified as nonassessable by TLUSG.

Although TLUSG is noninvasive and readily available,⁶ it requires acquisition of knowledge, practice, and accumulating experience to achieve an efficient, accurate, and proficient examination.³⁰ A study by Wong et al³⁰ investigated the learning curve of TLUSG in vocal cord assessment. After a short standardized training program, 8 surgical residents with no previous experience in ultrasound technique were able to master TLUSG skills after 7 examinations and assess vocal cord function consistently and accurately after 40 TLUSG.³⁰ Apart from being an easy-to-learn examination,⁶ TLUSG requires initial training to gain proficiency in performing the technique.^6,23 In view of this, there is a limitation if no professional with experience is available to perform the training.

The studies included in this review investigated laryngeal function after thyroidectomy and considered vocal fold immobility as a major negative impact on the voice, which affects patients’ social relationships and quality of life. This review found no evidence from the selected studies on the applicability of TLUSG for other purposes, even though the literature indicates the use of TLUSG in other populations as a noninvasive method to assess parameters related to swallowing, such as tongue thickness³¹ and hyolaryngeal displacement.^19,32,33 Only one study²³ briefly discussed the relationship between vocal fold immobility and dysphagia, which is characterized by episodes of increased tracheal aspiration. In addition to the voice, swallowing can be affected after thyroidectomy,³⁴ that is, TLUSG may be a promising procedure for the investigation of this function in these patients.

Conclusions

Transcutaneous laryngeal ultrasonography is a viable, noninvasive, and useful method to assess laryngeal function after thyroidectomy, especially changes in vocal fold mobility. However, it is not possible to confirm that TLUSG can replace direct flexible laryngoscopy for the diagnosis of vocal fold immobility. Although the results are controversial, TLUSG provides a good viewing rate of laryngeal structures, which should encourage further research, including the use of this procedure for other purposes such as analyzing swallowing-related parameters.

Footnotes

Declaration of Conflicting Interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

ORCID iD

Leandro Pernambuco

References

Santos

HCO

Amaral

Tacon

KCB

. A história da ultrassonografia no Brasil e no mundo [in Portuguese]. EFDeportes.com Rev Digit. 2012;17(167). http://www.efdeportes.com/efd167/ahistoria-da-ultrassonografia.htm. Accessed March 28, 2018.

Scarborough

Waizenhofer

Siekemeyer

Hughes

. Sonographically measured hyoid bone displacement during swallow in preschool children: a preliminary study. J Clin Ultrasound. 2010;38(8):430–434.

Dedecjus

Adamczewski

Brzeziński

Lewiński

. Real-time, high-resolution ultrasonography of the vocal folds—a prospective pilot study in patients before and after thyroidectomy. Langenbecks Arch Surg. 2010;395(7):859–864.

Wong

Woo

Youn

Chow

Lee

Lang

. The importance of sonographic landmarks by transcutaneous laryngeal ultrasonography in post thyroidectomy vocal cord assessment. Surgery. 2014;156(6):1590–1596.

Woo

Suh

Song

, et al. A novel lateral-approach laryngeal ultrasonography for vocal cord evaluation. Surgery. 2016;159(1):52–56.

Dubey

Mittal

Jaipuria

Arora

Dewan

Pahade

. Functional analysis of vocal folds by transcutaneous laryngeal ultrasonography in patients undergoing thyroidectomy. Acta Anaesthesiol Scand. 2018;63(2)178–186.

Cheng

Lee

Liu

Lee

Liu

. Preoperative ultrasonography assessment of vocal cord movement during thyroid and parathyroid surgery. World J Surg. 2012;36(10):2509–2515.

Barberena

Brasil

Melo

Mezzomo

Mota

Keske-Soares

. Ultrasound applicability in speech language pathology and audiology. CoDAS. 2014;26(6):520–530.

Kandil

Deniwar

Noureldine

, et al. Assessment of vocal fold function using transcutaneous laryngeal ultrasonography and flexible laryngoscopy. JAMA Otolaryngol Head Neck Surg. 2016;142(1):74–78.

10.

Tsui

Wan

Chen

. Ultrasound imaging of the larynx and vocal folds: recent applications and developments. Curr Opin Otolaryngol Head Neck Surg. 2012; 20(6):437–442.

11.

Boehm

Wichmann

Mozet

Dietz

. Current therapy options in recurrent head and neck cancer [in German]. HNO. 2010;58(8):762–769.

12.

Fortuny

Guigard

Karenovics

Triponez

. Surgery of the thyroid: recent developments and perspective. Swiss Med Wkly. 2015;145:w14144.

13.

Alvarenga

EHL

Cruz

OLM

. . Paralisia laríngea. In: Carrara-De-Angelis

Fúria

CLB

Mourão

Kowalski

. A atuação fonoaudiológica no câncer de cabeça e pescoço [in Portuguese]. São Paulo, Brazil: Editora Lovise; 2000;81–88.

14.

Geraldini

. Avaliação do efeito imediato de técnicas vocais na imobilidade unilateral de prega vocal [in Portuguese]. 2017. http://accamargo.phlnet.com.br/MESTRADO/2017/BrunaGeraladini/BrunaGeraladini.pdf. Accessed June 27, 2018.

15.

Richardson

Bastian

. Clinical evaluation of vocal fold paralysis. Otolaryngol Clin Nutri Am. 2004;37(1):45–58.

16.

Steffen

Moschetti

Steffen

Hanayama

. Unilateral vocal fold paralysis: association and correlation between maximum phonation time, position and displacement angle. Rev Bras Otorrinolaringol. 2004;70(4):450–455.

17.

Kılıç

MÖ

Terzioğlu

Gülçek

Sarı

. The role of ultrasonography in the assessment of vocal cord functions after thyroidectomy. J Invest Surg. 2018;31(1):24–28.

18.

Wong

Lang

Cheung

Chan

. A prospective assessor-blind evaluation of surgeons-performed transcutaneous laryngeal ultrasonography in vocal cord examination before and after thyroidectomy. Surgery. 2013;154(6):1158–1164.

19.

Lynch

Chammas

Mansur

Cerri

. Sonographic evaluation of swallowing biomechanics: a preliminary study. Radiol Bras. 2008;41(4):241–244.

20.

Leite

KKA

Mangilli

Sassi

Limongi

SCO

Andrade

CRF

. Ultrasonography and swallowing: a critical review of the literature. Audiol Commun Res. 2014;19:412–420.

21.

Mendes

KDS

Silveira

RCCP

Galvão

. Revisão integrativa: método de pesquisa para a incorporação de evidências na saúde e na enfermagem. [in Portuguese]. Texto Contexto Enferm. 2008;17(4):758–764.

22.

Downes

Brennan

Williams

Dean

. Development of a critical appraisal tool to assess the quality of cross-sectional studies (AXIS). BMJ Open. 2016;6(12):011458.

23.

De Miguel

Pelaez

Caubet

Gonzalez

Velasco

Rigual

. Accuracy of transcutaneous laryngeal ultrasound for detecting vocal cord paralysis in the immediate postoperative period after total thyroidectomy. Minerva Anestesiol. 2017;83(12):1239–1247.

24.

Borel

Delemazure

Espitalier

Spiers

Mirallie

Blanchard

. Transcutaneous ultrasonography in early postoperative diagnosis of vocal cord palsy after total thyroidectomy. World J Surg. 2016 40(3):665–671.

25.

Wong

Woo

Lee

Youn

Lang

. Using transcutaneous laryngeal ultrasonography (TLUSG) to assess post-thyroidectomy patients’ vocal cords: which maneuver best optimizes visualization and assessment accuracy? World J Surg. 2015;40(3):652–658.

26.

AMBNS: Associação Médica Brasileira e Agência Nacional de Saúde Suplementar. Doença Nodular de Tireóide: diagnóstico [in Portuguese]. 2011. http://www.projetodiretrizes.org.br/ans/diretrizes/doenca_nodular_da_tireoide-diagnostico.pdf. Accessed April 20, 2018.

27.

Randolph

Kamani

. The importance of preoperative laryngoscopy in patients undergoing thyroidectomy: voice, vocal cord function, and the preoperative detection of invasive thyroid malignancy. Surgery. 2006;139(3):357–362.

28.

Dralle

Lorenz

Machens

. Verdicts on malpractice claims after thyroid surgery: emerging trends and future directions. Head Neck. 2012;34(11):1591–1596.

29.

Fukuhara

Donishi

Matsuda

Koyama

Fujiwara

Takeuchi

. A novel approach to the assessment of vocal cord movement by ultrasonography. World J Surg. 2018; 42(1):130–136.

30.

Wong

Lang

Lam 2

Au KP

Chan

Kotewall

. Determining the learning curve of transcutaneous laryngeal ultrasound in vocal cord assessment by CUSUM analysis of eight surgical residents: when to abandon laryngoscopy. World J Surg. 2016 40(3):659–664.

31.

Tamura

Kikutani

Tohara

Yoshida

Yaegaki

. Tongue thickness relates to nutritional status in the elderly. Dysphagia. 2012;27(4):556–561.

32.

Kuhl

Eicke

Dieterich

Urban

. Sonographic analysis of laryngeal elevation during swallowing. J Neurol. 2003;250(3):333–337.

33.

Yabunaka

Sanada

, et al. Sonographic assessment of hyoid bone movement during swallowing: a study of normal adults with advancing age. Radiol Phys Technol. 2011;4(1):73–77.

34.

Scerrino

Tudisca

Bonventre

, et al. Swallowing disorders after thyroidectomy: what we know and where we are. A systematic review. Int J Surg. 2017;41(suppl 1):S94–S102.

Transcutaneous Laryngeal Ultrasonography for the Assessment of Laryngeal Function After Thyroidectomy: A Review

Abstract

Objective:

Methods:

Results:

Conclusions:

Keywords

Introduction

Materials and Methods

Search Strategy

Eligibility Criteria

Data Collection and Analysis Procedures

Results

Discussion

Conclusions

Footnotes

Declaration of Conflicting Interests

Funding

ORCID iD

References