Virtual Reality Helps Describe the Progression of Thyroid Cartilage Calcification

OBJECTIVES

Thyroid cartilage (TC) calcifications may impact surgical planning and clinical management. However, few studies to date have implemented virtual reality (VR) to evaluate these calcifications. This study assessed the feasibility of evaluating TC calcifications in various regions and measuring their volumes through VR models generated from computed tomography scans. We also investigated age and gender-related differences in calcification patterns.

METHODS

Ninety-two participants were categorized into younger, middle-aged, and older age groups. Calcification patterns (degree in Hounsfield units and volume of calcification in cm3) in different TC regions were identified by VR analysis, which enabled comparisons between age groups and genders.

RESULTS

Significant differences in calcification patterns were observed between males and females, particularly in the middle right, middle left, bottom left, and vertex regions. Age-related differences in the vertex region showed increased calcification in the older age group.

CONCLUSION

This study points to the contribution of VR in the evaluation of complex anatomical structures. The findings revealed significant gender and age patterns in TC calcification. These insights can inform surgical planning and highlight the potential of using VR to gain a better understanding of TC calcification clinically.

Lowered hyoid bone overlapping the thyroid cartilage in CT angiograms

BACKGROUND

The ventral enclosure of the thyroid cartilage by a collapsed hyoid bone (CHB) is poorly encountered in previous research. It was aimed to observe whether or not these malformations could be found and detailed anatomically in a consistent lot of computed tomography (CT) files.

METHODS

Two hundred archived CT angiograms were explicitly observed for the CHB anatomical variant.

RESULTS

Different possibilities of CHB were found in 6/200 cases, five males and one female. The symmetrical overlap of the thyroid cartilage by the hyoid body was found in one male case. In three cases, two males and one female, there was asymmetrical overlapping due to tilted hyoid bones. In one male case with such asymmetrical CHD, an ossified anterior longitudinal ligament was noted: the tips of the superior horns of the thyroid cartilage reached lateral to it, thus being retropharyngeal. A different male case had a lowered hyoid with a greater horn fused to the superior horn of the thyroid cartilage, with an interposed ossified triticeal cartilage. In the last male case, the right greater horn collapsed laterally to an ossified triticeal cartilage fused with the thyroid cartilage's superior horn.

CONCLUSIONS

The CHB is an undeniable anatomical possibility of an atavism that alters conventional anatomical and surgical landmarks. Different anatomical components of the hyoid bone can descend uni- or bilaterally.

Favourable swallowing outcomes after subtotal glossectomy with laryngeal suspension

Subtotal or total glossectomy for advanced tongue cancer has an adverse impact on swallowing. The purpose of this retrospective study was to analyse postoperative swallowing outcomes and to determine the ideal reconstruction method in these patients. The clinical and swallowing data of patients with tongue cancer who underwent subtotal glossectomy at the study institution between 2005 and 2019 were reviewed retrospectively. Data were available for 101 patients. The most common reconstruction method was a free rectus abdominis musculocutaneous flap (69 cases). The postoperative feeding tube dependency rate was 11.1% at discharge and 9.4% at 1 year. During the study period, laryngeal suspension and/or a cricopharyngeal myotomy was performed in 39 patients (38.6%), with 25 of these operations performed after 2017. Patients treated in 2017-2019 were significantly more able to take thin liquid (P < 0.001) and lost less weight (P = 0.015) compared to those treated in 2005-2016. Multivariate analysis of 61 patients who did not undergo laryngeal suspension and/or cricopharyngeal myotomy showed significant feeding tube dependency in those aged 65 years and older (P = 0.004). Thin liquid intake was significantly improved after subtotal glossectomy with laryngeal suspension, which led to better postoperative swallowing and improved quality of life.

Spontaneous longitudinal rupture of the thyroid cartilage: A management of the rare clinical case

INTRODUCTION AND IMPORTANCE

Non-traumatic rupture or other injuries to the larynx are very rare disorder. According to the published series, there are only 15 cases reported with such kind of injury to the larynx. Despite the rarity of the non-traumatic larynx fracture, it is important to elucidate adequate management for the patients with such emergency. The aim of the study is to demonstrate the features of clinical manifestations, examination, and surgical treatment of a case of spontaneous longitudinal rupture of the thyroid cartilage.

PRESENTATION OF CASE

A 54-year-old male patient presented with chief complaints of pain in the front surface of the neck, difficulty swallowing and breathing during physical exertion, hyperemia of the skin on the front surface of the neck, and the presence of subcutaneous emphysema. 20 h after the onset of the symptoms, the patient reported breathing difficulties that appeared during physical exertion, and the patient walked to the hospital. Computed tomography revealed a longitudinal rupture of the thyroid cartilage, emphysema of the neck, and the presence of air in the anterior-upper mediastinum. The defect of the ruptured thyroid cartilage was treated by suturing as well as by myoplasty using sternocleidomastoid muscle.

CLINICAL DISCUSSION

Our case report is in line with others, showing that patient with spontaneous rupture of the thyroid cartilage is the surgical emergency. Our approach of using myoplasty was not presented before.

CONCLUSION

This case report adds evidence and knowledge about such rare disorders as spontaneous rupture the thyroid cartilage rupture. It is useful to apply the technique of myoplasty with sternocleidomastoid muscle flaps, ensuring reliable sealing of the damaged area reducing the risk of failure, and inflammatory complications, and supporting neck functions in the postoperative period.

Systematic review of laryngohyoid fractures in fatal falls: A potential mimicker of strangulation

Fractures of the laryngohyoid complex are classically associated with deaths due to strangulation. Recent studies, however, indicate the possible presence of such fractures in fatal falls. The primary focus of this systematic review is to analyze the characteristics of laryngohyoid fractures in the context of falls to aid in a more accurate interpretation of autopsy findings. Search for relevant literature occurred on PubMed on the 26th of October 2022, and Embase and Web of Science on the 5th of November 2022. Inclusion criteria included being a primary study, published in English, involving fatal falls and injuries to the laryngohyoid complex, and presenting sufficient details about the relevant cases. Four case reports and six descriptive retrospective studies were included in the final analysis yielding a sum of 38 cases. The risk of bias was assessed using the Joanna Briggs Institute (JBI) critical appraisal tools. Potential limitations of this study include the inclusion of case reports and studies published in English only. The cumulative male-to-female ratio was 23:15 with a mean age of 48 years old. The fall height ranged from standing height to 60 m. Forty-three fractures to the laryngohyoid complex were identified with the thyroid cartilage most commonly affected, followed by fracture of the hyoid bone, and finally the cricoid cartilage. While cases of falls did indeed display hallmark laryngohyoid findings classically displayed in strangulation, they also featured unique presentations such as fractures of the clavicle and a reduced prevalence of conjunctival petechiae.

Equivalence of the top-down manoeuvre and bottom-up manoeuvre in speed and accuracy of identifying the cricothyroid membrane: a prospective randomised cross-over study

BACKGROUND

Accurate identification of the cricothyroid membrane is crucial for successful cricothyrotomy; however, a manoeuvre that helps identify it both accurately and quickly remains unclear. The effectiveness of the so-called 'bottom-up manoeuvre' has never been investigated. This study aimed to examine whether the bottom-up manoeuvre is as rapid and accurate as the conventional 'top-down manoeuvre' at identifying the cricothyroid membrane.

METHODS

This study was a prospective randomised cross-over trial conducted at an academic medical centre between 2018 and 2019. Fifth-year medical students participated. The students were trained in the use of either the top-down manoeuvre or the bottom-up manoeuvre first. Each student subsequently performed the technique once on a volunteer. The students were then taught and practiced the other manoeuvre as well. The accuracy of cricothyroid membrane identification and the time taken by successful participants only were measured and compared between the manoeuvres using equivalence tests with two one-sided tests.

RESULTS

A total of 102 medical students participated in this study and there was no missing data. The accuracy of identification and time required for success were similar between the top-down manoeuvre and the bottom-up manoeuvre (65.7% vs. 70.6%, taking 13.8 s [interquartile range (IQR): 9.4-17.5] vs. 15.5 s [IQR: 11.5-19.9], respectively). The success rate was statistically equivalent (rate difference, 4.9%; 90% confidence interval [CI], -5.8 to 15.6; equivalence margin, -20.0 to 20.0). The time required for success was also statistically equivalent (median difference, 1.7 s; 90% CI, -0.2 to 3.3; equivalence margin, -4.0 to 4.0).

CONCLUSION

Among students first trained in both manoeuvres for identifying the cricothyroid membrane, the speed and accuracy of identification were similar between those using the bottom-up manoeuvre and those using the top-down manoeuvre.

Evaluation of morphological features of palatopharyngeus insertion into the thyroid cartilage

The attachment of the palatopharyngeus extended from the posterior end of the thyroid cartilage to the posterior margin of the inferior constrictor attachment that might contribute to successive swallowing movements. Laryngeal elevation is essential for proper swallowing and breathing. Recently, clinical research has demonstrated that the palatopharyngeus, a longitudinal muscle of the pharynx, is involved in the elevation of the larynx. However, the morphological relationship between the larynx and palatopharyngeus remains unclear. In the present study, we analyzed the attachment site and characteristics of the palatopharyngeus in the thyroid cartilage. We evaluated 14 halves of seven heads from Japanese cadavers (average age: 76.4 years); 12 halves, anatomically and two halves histologically. A part of the palatopharyngeus, which originated from the inferior aspect of the palatine aponeurosis, was attached to the inner and outer surfaces of the thyroid cartilage through collagen fibers. The attachment area extends from the posterior end of the thyroid cartilage to the posterior margin of the attachment site of the inferior constrictor. The palatopharyngeus may elevate the larynx with the suprahyoid muscles and contribute to successive movements of swallowing with surrounding muscles. Based on our findings and previous studies, palatopharyngeus with various muscle bundle directions may be essential for the coordination of continuous swallowing events.

The first report of the buckled thyroid cartilage in a human cadaver

We present the first case of buckled thyroid cartilage identified in a human cadaver. This rare anatomical variant, in patients, often produces dysphonia and is a potential source for diagnostic confusion. In the cadaveric case described, the laryngeal prominence is deviated to the left without deviation of the internal structures of the larynx, such as vocal folds and vocalis muscles. The medical history of the patient is not known. Finally, a review of current literature on the buckled thyroid cartilage is presented. Such a case represents a rare opportunity to visualize this deformity via anatomical dissection.

Relationship of Recurrent Laryngeal Nerve with Inferior Horn of Thyroid Cartilage, Berry's Ligament and Zuckerkandl's Tubercle

During neck surgery; Zuckerkandl's tubercle, Berry's ligament, the inferior horn of thyroid cartilages have become crucial anatomical landmarks in order to protect the integrity of the recurrent laryngeal nerve. Forty-two male postmortem human cadavers were used. The proximal part of the recurrent laryngeal nerve, before the inferior thyroid artery arises from its source has been observed in 87% inside the tracheoesophageal groove and in 13% running laterally to the trachea. The recurrent laryngeal nerve was encountered passing behind and through the branches of the inferior thyroid artery in 92% and 8% respectively. At all sides; the nerve was piercing the larynx 0.6 ± 0.1 mm below the inferior horn of thyroid cartilage, passing next to the inner-lower side of Berry's ligament and running under the lower middle part of Zuckerkandl's tubercle. These landmarks and their upper mentioned distances to the laryngeal nerve can be taken into consideration as important surgical guides.

Variables predictive of surgical outcomes after hyoid myotomy with suspension to thyroid cartilage

OBJECTIVES

To evaluate variables predicting improvement in obstructive sleep apnea (OSA) with hyoid suspension to thyroid cartilage 4-suture technique.

METHODS

Sixty adult patients (age range 23-78 years) with OSA underwent hyoid suspension to thyroid cartilage with or without concurrent multi-level surgery over an eight-year period from 2011 to 2019 at a tertiary academic center. All patients had a preoperative apnea hypopnea index (AHI) ≥ 5. Changes in mean AHI, Epworth Sleepiness Scale (ESS), and lowest oxygen saturation (LSAT) were measured with paired Student t-test. Linear and logistic regression models were used to predict change in AHI and surgical success respectively with respect to body mass index (BMI), age, sex, previous sleep surgery, concurrent retrolingual surgery, concurrent palatopharyngoplasty, and preoperative AHI.

RESULTS

The mean AHI demonstrated a significant improvement from a preoperative AHI of 39.0 ± 25.5 to a postoperative AHI of 31.2 ± 23.4 (p = 0.005). The mean Epworth Sleepiness Score (ESS) significantly improved from 13.1 ± 6.0 to 9.2 ± 5.7 (p = 0.000012). Surgical success, defined as a 50% reduction in preoperative AHI to a postoperative AHI ≤ 20, was obtained in 18/60 (30.0%) patients. Preoperative BMI significantly correlates with variation of change in AHI in multivariable linear regression model (p = 0.003). Preoperative AHI was significant predictor of surgical success in multivariable logistic regression model.

CONCLUSION

The magnitude of improvement in polysomnographic parameters after hyoid suspension to thyroid appears to be more significant in patients with lower BMI. Even patients with an obese BMI and severe OSA achieve significant improvement from this procedure.

Age related changes in thyroid and cricoid cartilages: An autopsy based radiological analysis

Forensic age estimation is an invaluable aspect of human identification. Out of these many means of age estimation, few regions with untapped potential for assistance in forensic age estimation are the age-related changes in the laryngeal cartilages. As the age advances, the thyroid and cricoid cartilages undergo gradual calcification in an individual. These age-related changes can be visualized in both the living and the dead using conventional radiography and can be objectively assessed. The objective of the present study was to evaluate the age-related changes in the laryngeal cartilages and the results may be utilized for age estimation in forensic examinations. The laryngeal cartilages were carefully dissected using standard procedures from 75 cadavers of age ranging from 17 to 65 years, during the post-mortem examination. The laryngeal cartilages were radiographed and replaced in the body cavity before culminating the post-mortem examination. The calcification of both cartilages was studied by using the standard grading method. Calcification scores of individual regions of both the laryngeal cartilages show a statistically significant positive correlation with chronological age (P < 0.05). Regression models derived from the degree of calcification of thyroid and cricoid cartilages showed standard error of estimates that ranged between 9.90 and 11.07 years. Considering the standard error of estimates of the regression analysis, the present study concludes that these regression models can be used in adjunct with other methods of age estimation such as the skeletal and dental age or when such methods are not viable as in cases of charred or mutilated remains.

Experience performing partial fistulectomy through a single incision to treat pyriform sinus fistula in children

BACKGROUND AND OBJECTIVES

The surgical treatment of pyriform sinus fistula (PSF) is improving. The aim of this study was to investigate the effect of partial fistula excision in children with PSF assisted by using methylene blue.

METHODS

According to the method used to treat PSF infection, the patients were divided into a conservative treatment group, a single incision group (the children drained the abscess through the incision at the dermatoglyph of the cricothyroid joint), and a non single incision group (the children drained the abscess through the incision in the most obvious area of the abscess or ulceration). The data were retrieved from the electronic medical records (EMRs) and hospital information system （HIS）. The patient and observer scar assessment scale (POSAS) scores at 6 months after fistula resection were compared.

RESULTS

A total of 239 patients diagnosed with PSF underwent partial resection of the fistula through cervical approach with methylene blue. The success rate of the operation was 100%. The average operation time was 32 ± 13.2 min. The average hospital stay was 1 ± 0.2 days. There were 2 cases of transient hoarseness and 6 cases of wound infection. There were 17 patients in the conservative treatment group, 81 patients in the single incision group and 145 patients in the nonsingle incision group. The average POSAS scores of the three groups were 2.56 ± 0.6, 3.12 ± 0.84 and 4.56 ± 1.56, respectively, with significant differences among the three groups (P < 0.05).

CONCLUSIONS

Partial fistulectomy assisted by using methylene blue through a single incision in the neck for the treatment of PSF in children yields a high success rate, fewer postoperative complications and greater comfort than traditional surgery. This alternative surgery can be used to treat PSF in children.

Modeling one-handed grip strangulation: Intentionality of the gesture and age influence

Strangulation is a violent act which can be lethal and is often studied in forensic context. The neck includes several anatomical elements that can evolve with aging. We therefore created a numerical human neck model including the main anatomical elements and simulated one-handed grip strangulation cases. In addition, we created 3 models each representing age groups: 20-30 years old, 30-50 years old and over 50 years old. The main changes between the different age groups are the ossification of the cartilages and the muscles mechanical properties. Several initial and boundary conditions have been tested to perform a realistic simulation of one-handed grip strangulation. Stress analysis and fracture observation were compared with the grip strength of an average man, 552 N, to look at the intentionality of the gesture. In each age group, the results show no model fracture for a force of 552 N. It is necessary to reach a minimum of 1406 N before observing a first fracture on the hyoid bone. However, it is possible to get stresses on the hyoid bone and on the thyroid cartilage way before 552 N. It thus appears that the force created by one-handed grip strangulation is not sufficient to cause fractures of the bony elements of the neck, but it remains sufficient to compress the larynx and at least reduce airflow.

The clinical significance of remnant thyroid tissue in thyroidectomized differentiated thyroid cancer patients on 131I-SPECT/CT

BACKGROUND

To explore the ¹³¹I-SPECT/CT characteristics of remnant thyroid tissue (RTT) in differentiated thyroid cancer (DTC), further assess the risk factors and clinical significance.

METHODS

52 DTC patients after total thyroidectomy had undergone neck ¹³¹I-SPECT/CT before ¹³¹I ablation. The diagnosis of RTT was based on SPECT/CT and follow-up at least 3 months. The anatomic locations and features of SPECT/CT of RTT were assessed by reviewers. The risk factors of RTT with CT positive were analyzed by the chi-square test.

RESULTS

A total of 80 lesions of RTT were diagnosed in this study, most of them were mainly located in the regions adjacent to trachea cartilage (37/80) or lamina of thyroid cartilage (17/80). On SPECT/CT of RTT, low, moderate and high uptake were respectively noted in 10, 24 and 46 lesions, definite positive, suspected positive and negative CT findings were respectively noted in 10, 21 and 49. The RTT lesions with definite positive CT findings were mainly located adjacent to lamina of thyroid cartilage (5/10). Primary thyroid tumor (P = 0.029) and T stage (P = 0.000) were the effective risk factors of CT positive RTT.

CONCLUSIONS

RTT has certain characteristic distribution and appearances on SPECT/CT. Most of RTT with definite CT abnormalities located adjacent to lamina of thyroid cartilage, which suggest surgeons should strengthen the careful removal in this region, especially primary thyroid tumor involving bilateral and T4 stage. This study can provide a certain value for the improvement of thyroidectomy quality in DTC patients.

Incidence and factor analysis of laryngohyoid fractures in hanging individuals-computed tomography study

OBJECTIVES

Although laryngohyoid fracture indicates the applied neck pressure and is an important finding in hanging individuals, the reported rate varies widely and its true incidence remains controversial. We used computed tomography (CT) studies to investigate the incidence of laryngohyoid fracture in hanging individuals and identify factors contributing to such fractures.

METHODS

Considered for inclusion in this study were 107 attempted or successful hanging individuals subjected to CT studies between 2005 and 2019. After excluding 19 whose images were inadequate for evaluation, 88 subjects were included. Body suspension was complete in 20, partial in 49, and unknown in 19; 54 (61.4%) individuals died. Two radiologists performed image analysis and recorded the presence and site of laryngohyoid fractures. Multiple logistic regression analysis was used for factor analysis of laryngohyoid fractures; it included the gender, the age (< or ≧ 40 years), the type of suspension (complete or incomplete), and the outcome (death or survival).

RESULTS

Of the 88 subjects, 35 (39.8%) presented with laryngohyoid fractures on CT images; the superior horn of the thyroid cartilage was fractured in 32 (91.4%) of the 35. Age was the only factor significantly related to laryngohyoid fracture (odds ratio = 2.85, 95% confidence interval = 1.08-7.52).

CONCLUSIONS

In hanging individuals, the incidence of laryngohyoid fracture on CT images was 39.8%. The superior horn of the thyroid cartilage was the most frequent fracture site.

KEY POINTS

• The incidence of laryngohyoid fracture on CT images of hanging individuals was almost 40%; the superior horn of the thyroid cartilage was the most frequent fracture site. • In older hanging individuals, attention must be paid to laryngohyoid fractures on CT images.

Forceful sneeze: An uncommon cause of laryngeal fracture

Laryngeal fractures are generally induced by direct blunt or penetrating trauma to the neck. Coughing vigorously or sneezing forcefully is extremely rare causes of laryngeal fractures, with only 4 cases found after thorough literature search. Herein we present a case of a 34-year-old male presenting to the ENT emergency room with throat pain, odynophagia, dysphagia, and hoarseness. Following primary evaluation, through physical examination and imaging he was diagnosed with thyroid cartilage fracture and treated conservatively. The triad of odynophagia, dysphagia, and dysphonia after a severe episode of coughing or sneezing in a young adult male patient should prompt suspicion of a laryngeal fracture.

CT-based radiomics features in the prediction of thyroid cartilage invasion from laryngeal and hypopharyngeal squamous cell carcinoma

Background

Laryngeal and hypopharyngeal squamous cell carcinoma (LHSCC) with thyroid cartilage invasion are considered T4 and need total laryngectomy. However, the accuracy of preoperative diagnosis of thyroid cartilage invasion remains lower. Therefore, the purpose of this study was to assess the potential of computed tomography (CT)-based radiomics features in the prediction of thyroid cartilage invasion from LHSCC.

Methods

A total of 265 patients with pathologically proven LHSCC were enrolled in this retrospective study (86 with thyroid cartilage invasion and 179 without invasion). Two head and neck radiologists evaluated the thyroid cartilage invasion on CT images. Radiomics features were extracted from venous phase contrast-enhanced CT images. The least absolute shrinkage and selection operator (LASSO) and logistic regression (LR) method were used for dimension reduction and model construction. In addition, the support vector machine-based synthetic minority oversampling (SVMSMOTE) algorithm was adopted to balance the dataset and a new LR-SVMSMOTE model was constructed. The performance of the radiologist and the two models were evaluated with receiver operating characteristic (ROC) curves and compared using the DeLong test.

Results

The areas under the ROC curves (AUCs) in the prediction of thyroid cartilage invasion from LHSCC for the LR-SVMSMOTE model, LR model, and radiologist were 0.905 [95% confidence interval (CI): 0.863 to 0.937)], 0.876 (95%CI: 0.830 to 0.913), and 0.721 (95%CI: 0.663–0.774), respectively. The AUCs of both models were higher than that of the radiologist assessment (all P < 0.001). There was no significant difference in predictive performance between the LR-SVMSMOTE and LR models (P = 0.05).

Conclusions

Models based on CT radiomic features can improve the accuracy of predicting thyroid cartilage invasion from LHSCC and provide a new potentially noninvasive method for preoperative prediction of thyroid cartilage invasion from LHSCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40644-020-00359-2.

Dynamic 3D-CT angiography during swallowing for diagnosing hyoid bone or thyroid cartilage compression-induced thromboembolism

A 76-year-old man was admitted because of visual loss in his right eye, and was diagnosed with central retinal artery occlusion. Brain MRI revealed asymptomatic acute infarctions in the right middle cerebral artery territory. The proximal right internal carotid artery had migrated into a retropharyngeal location, presenting a 50% stenosis with calcified plaques, and was compressed by the hyoid bone and thyroid cartilage during swallowing on dynamic 3D-CT angiography. Partial resection of the hyoid bone and thyroid cartilage was performed and the postoperative course was uneventful. This case supports the utility of dynamic 3D-CT angiography during swallowing for diagnosing hyoid bone or thyroid cartilage compression-induced thromboembolism.

An Unusual Case of Simultaneous Cricoid and Thyroid Cartilage Metastases from Prostatic Adenocarcinoma on 68Ga-PSMA PET/CT

Although prostate cancer can metastasize to any part of the body, laryngeal cartilage metastasis is extremely rare and few cases have been published so far. Here we present the case of a 65-year-old male patient, recently diagnosed with prostate adenocarcinoma, referred for staging with ⁶⁸Ga-PSMA PET/CT. He was found to have extensive skeletal metastasis along with cartilage metastasis involving both thyroid and cricoid cartilages.

[The application of thyroid alar cartilage in the reconstruction of subglottic stenosis for children]

Objective: To explore the application value of thyroid alar cartilage(TAC) in the laryngotracheal reconstruction of subglotticstenosis in the paediatric population. Methods: Twelve patients(7 males,5 females; range from 2.3 to 12.0 years) with subglotticstenosis who had undergone laryngotracheal reconstruction procedures at our hospital fromSeptember 2016 to July 2018 were analyzed retrospectively.The degree of stenosis was classified according to Myer-Cotton classification system:grade Ⅱ(n=4),grade Ⅲ(n=6) and grade Ⅳ(n=2). The stenosis planes were subglotticbut did not exceed the 3rd tracheal cartilage ring. Results: Of all 12 patients, 11 were decannulated and 1 failed. All patients with grade Ⅱ and Ⅲ patients were decannulated at one procedure. There were no severe complications such as tube dislogement,asphyxia and unhealed wound. Conclusions: The TAC for widening laryngotracheal lumen is relatively simple and reliable for laryngotracheal reconstruction in the pediatric population with subglottic stenosis. This would't cause any structural damage to the laryngeal cavity.

Biomechanical study of the thyroid cartilage: A model of bi-digital strangulation

The presence of fracture on neck elements is an indication of violence. Both the hyoid bone and the larynx can be damaged by a strangulation mechanism. Thyroid cartilage, more specifically, may present lesions in response to this mechanical stress. These lesions result in fractures at the bases of the horns of the thyroid cartilage. This study focuses on the thyroid cartilage behavior in cases of bi-digital strangulation, using an anthropometric and biomechanical approach. To develop a biomechanical model, we performed an anthropometric study taking into account 14 distances measurements as well as 3 measurements of angles. These measures allowed us to determine a significant sexual dimorphism between individuals. Then, we define 6 morphologies models, composed of 3 females and 3 males individuals. In order to visualize the ossification of the cartilage, each model has been tested with bone properties. Strangulation cases were simulated by applying an imposed velocity of 0.4m/s then 1m/s. We observed different behaviors of the thyroid cartilage according to the sex and the morphology.

In silico investigation of sneezing in a full real human upper airway using computational fluid dynamics method

BACKGROUND AND OBJECTIVE

Sneezing is one of the most critical conditions that can occur in the human upper airway. As some reports confirm the injury to the human upper respiratory airway while sneezing. Therefore, the accurate study of the distribution of pressure and velocity in this case is of great importance.

METHODS

In the present study, using a real human upper airway model, the pressure and velocity of the airflow generated in the tract during the sneezing have been investigated. Also, considering the results from a spirometer device as a boundary condition in the simulation process, the calculations have become reliable.

RESULTS

According to the results, during sneezing, taking into account that the average outlet flow rate from the mouth is 4.79 L/s, the velocity of outlet airflow from the mouth and nose reaches 5.3 and 8.4 m/s, respectively. These values were 11.5 and 19, respectively, when the desired maximum flow rate was 10.58 L/s. It can be concluded that the increasing of trachea flow rate, leads to higher percentage of the outlet flow rate from the nose . The highest average pressure and velocity have been occurred in the trachea. Among other salient results of this report, increased average static pressure of larynx to approximately 10 kPa can be pointed which indicates that this area is critical so that the thyroid cartilage defect is likely to occur. It is also noteworthy that the increase of speed at nasopharynx is up to 125 m/s so that the cross-section changing in this area leads the fluid acts as a jet flow. Due to the specific geometry of the nasal cavity, some streams similar to poor shocks are formed, these shocks get stronger by increasing of the flow rate. The thyroid cartilage and nasal cavity are exposed to maximum static pressure extremums, respectively.

CONCLUSIONS

We introduced a model simulating a normal sneezing for two cases using a healthy 30-year-old male person. We believe that the model should be applied for different persons and an atlas of data could be obtained from different cases. This may help the medical system to have more data about the sneezing process.

Unilateral and bilateral agenesis of the upper thyroid horns - A morphometric analysis of the larynx

The agenesis of one or both upper thyroid horns (UTH) cannot be considered rare with an incidence ranging between 0.8-9.4%. Studies so far have mostly described frequencies, yet surveys on its morphology and traumatology are missing. It is unknown to what extent this anatomical variant impacts the overall symmetry of the larynx. For the trauma reconstruction after cervical trauma this knowledge is required as an asymmetric larynx can show a different fracture pattern. In this investigation, larynxes with unilateral (n=21)/bilateral (n=5) agenesis of the upper thyroid horn(s) and a control group with regular larynxes (n=23) were juxtaposed. Various measurements were taken after μ-CT scanning. In total 10 distances/angles for the thyroid cartilage and 8 for the cricoid cartilage were compared. Using intra-individual and matched pair comparisons the symmetry was assessed. The results of this investigation showed significant differences in the intra-individual and pairwise comparison for the opening angle and the length of the thyroid alae although the lateral inclination of the thyroid alae showed no significant difference. Combining these three parameters into one symmetry score, the comparison was not significant. This research demonstrates that neither unilateral nor bilateral agenesis of the UTH is related to a structural disbalance of the larynx. Thus, different fracture patterns or vulnerabilities are not to be expected.

Morphological Evaluation of Thyroid Cartilage Invasion in Early Glottic Tumors Involving the Anterior Commissure

INTRODUCTION

The anterior commissure is an area of glottic cancer infiltration, even in early stages.

OBJECTIVE

To evaluate the invasion by tumors into the anterior commissure cartilage in surgical specimens of frontolateral laryngectomy.

METHODS

Forty-eight patients who had undergone frontolateral laryngectomy for T1b/T2 squamous cell carcinoma were included. Epidemiological and clinical aspects as well as morphological histopathological analysis were evaluated.

RESULTS

Of the 48 patients, 42 (87.5%) had T1b lesions and 6 (12.5%) had T2. Thirty-four cases (70.8%) showed healthy tissue between the tumor and the thyroid cartilage, 10 cases (20.8%) had a tumor in close proximity to the cartilage, and in 4 cases (8.3%) there was cartilage invasion. There was no major risk of adverse outcome in the groups with infiltration or tumor adjacent to the cartilage. Level of differentiation, mitotic index, nuclear irregularity, and the presence of nucleolus and tumor necrosis were not related to cartilage invasion.

CONCLUSION

The infiltration of thyroid cartilage occurred in 8.3% of tumors and did not change the outcome in patients submitted to frontolateral laryngectomy. The morphological characteristics did not present any statistical significance.

Laryngeal anatomical variants and their impact on the diagnosis of mechanical asphyxias by neck pressure

The aims of this investigation were to determine the characteristics and prevalence of anatomical variants of the larynx apparatus and to evaluate the impact of these variants on the accurate diagnosis of laryngeal fractures. A population-based study was carried out, analyzing a series of 207 consecutive autopsied cases in the Institute of Legal Medicine of Galicia (Northwestern Spain). The prevalence of triticeal cartilage was 52.7% and that of agenesis of thyroid horns 10%. Calcification of the stylo-hyoid ligament accounted for 1.4%. We identified three new anatomical variants: the terminal segmentation of the thyroid horns (11.6%), ectopic superior thyroid horns (8%) and lateral thyrohyoid ossification (5.3%). These three names, based on anatomical criteria, are the author's proposal to solve the lack of uniformity in the designation of these variants. Agenesis of thyroid horns were related to the presence of ectopic superior thyroid horns in 93% of cases, either uni or bilateral. The combination of variants was present in 6.8% of the cases, being the terminal segmentation of the thyroid horns in association with triticeal cartilage the most frequent (3.8%). The probability of misdiagnosis due to the presence of anatomical variations in deaths by pressure on the neck was high in this population (71.5%). The prevalence of triticeal cartilage in more than half of the sample, determined an important rate of potential errors (46.4%), followed by the mistaken diagnoses induced by terminal segmentation of thyroid horns (7.3%) and by ectopic superior thyroid horns (6.3%). The likelihood of a misdiagnosed laryngeal fracture was greater if the thyroid cartilage was affected, with a higher proportion of false positives comparing to the hyoid bone (p<0.001). The higher frequency of thyroid fractures in neck pressure together with the prevalence and location of triticeal cartilage on the lower third of the lateral thyrohyoid ligament are the main reasons for these results. Further studies should be done with larger samples to expand epidemiological data and consolidate these results and their influence on the diagnosis of mechanical asphyxias.

Normal radiological anatomy of thyroid cartilage in 600 Chinese individuals: implications for anterior cervical spine surgery

Background

Thyroid cartilage is an important barrier in anterior cervical approach surgery. The objective of this study is to establish normative values for thyroid cartilage at three planes and to determine their significance on preoperative positioning and intraoperative traction in surgery via the anterior cervical approach.

Methods

Neck CT scans were collected from 600 healthy adults who did not meet any of the exclusion criteria. Transverse diameters (D1, D2, and D3) of the superior border of the thyroid cartilage (SBTC), inferior border of the thyroid cartilage (IBTC), and the trachea transverse diameters of the inferior border of the cricoid cartilage (IBCC) were measured on a horizontal plane.

Results

All measured variables had intra-class correlation coefficients (ICCs) of ≥ 0.7. The differences in transverse diameters on the same plane between males and females were significantly different (all p < 0.001). The SBTC is most often at C4 in women (59.5%) and C4/5 in men (36.4%), the IBTC is most often at C5 in women (48.1%) and men (46.2%), and the IBCC is primarily located at C6 in women (45.2%) and C6 or C6/7 in men (34.4%) (all p < 0.001).

Conclusion

We present normative values for thyroid cartilage at three planes of SBTC, IBTC, and IBCC in Chinese individuals. The individual and gender differences in the location of the thyroid cartilage and the size of the thyroid cartilage and the cricoid cartilage provide an anatomical basis to localize the skin incision, to predict the difficulty of intraoperative exposure and retractor pulling, and to identify that the thyroid cartilage protected the pharyngoesophageal wall.

Can thyromental distance be measured accurately?

Using the thyromental distance (TMD) measured based on the ultrasonographic location of the thyroid cartilage prominence as the criterion, we investigated the accuracy of TMD measurement by surface landmark identification of the thyroid cartilage prominence. Twenty-nine anesthetist resident volunteers were recruited, including 10 first-year residents, 9 second-year residents and 10 third-year residents. Each volunteer measured the other 28 volunteers’ TMD. Then, the thyroid cartilage prominence of each volunteer was identified by ultrasonography of the junction of the vocal cord and thyroid cartilage, and the TMD was measured precisely. The error of the TMD measurement was determined by the minimal detectable difference (MDD) compared to the ultrasound measurement. A difference of greater than 5.4 mm between the TMD measured by volunteers and that based on ultrasound localization was defined as a measurement error. The measurement error rate of females’ TMD was significantly higher than that of males’ (50 vs 10%, P < 0.001). The error rates of anesthetist residents of first-year, second-year and third-year were 34, 27, and 31%, respectively, and were not significantly different. The error of TMD measurement by surface landmark identification is often, especially for women. More clinic experience don’t improve it.

Buckled Thyroid Cartilage: An Anatomic Variant

OBJECTIVE

Anatomic abnormalities in the larynx can cause significant and bothersome symptoms. Identified here is an anatomical variant of the thyroid cartilage.

STUDY DESIGN

This study is a retrospective case series of 11 subjects diagnosed with an anatomic variant of the thyroid cartilage.

METHODS

Patients with an anatomic inward buckling of the thyroid cartilage, termed here as buckled thyroid cartilage, were identified through a 20-year retrospective chart review of a tertiary care laryngology practice.

RESULTS

We describe 11 patients with fullness or asymmetry in the area of the false vocal fold and an associated inward buckling of the thyroid cartilage on computed tomography scan. All patients presented with a bothersome voice-related complaint. The most common presenting complaints were hoarseness (54%), globus sensation (45%), or vocal fatigue (27%). One patient was found to have a history of known laryngeal trauma. Surgical correction through an external approach on one patient was successfully performed with subsequent resolution of symptoms.

CONCLUSION

We postulate that deformity and protrusion of the false vocal fold can result in a dampening effect on the vibratory capacity of the vocal fold that can lead to symptomatic hoarseness and vocal fatigue. Buckled thyroid cartilage is, therefore, an important anatomical variant to be aware of and be able to recognize.

[Diagnostic value of enhanced CT/MRI for thyroid cartilage invasion by malignant tumor]

Objective: To evaluate the values of enhanced CT and MRI for the diagnosis of thyroid cartilage invasion by laryngeal and hypopharyngeal cancer. Methods: One hundred and ninety-seven patients with primary laryngeal or hypopharyngeal cancer treated with surgery between January 2013 and December 2014 were included in this study. All patients underwent enhanced CT and MRI before surgery. With MRI using the techniques of fast recovery fast spin echo (FRFSE), spin echo echo planar imaging (SE-EPI) and diffusion weighted imaging (DWI), thyroid cartilage invasion was evaluated and the results of postoperative histopathological examination was used as a gold standard for the determination of thyroid cartilage invasion. The sensitivity, specificity, positive predictive value and negative predictive value of enhanced CT or MRI in detecting thyroid cartilage invasion by laryngeal and hypopharyngeal cancer were evaluated. Data were analyzed with SPSS17.0 software. Results: Among 197 patients, there were 35 cases with supraglottic laryngeal cancer, 92 cases with glottic laryngeal cancer, 9 cases with subglottic laryngeal cancer, and 61 cases with hypopharyngeal cancer. Postoperative pathologycal examinations showed that 63 (32.0%) of 197 patients had thyroid cartilage invasion by tumor. Based on TNM classification of AJCC (American Joint Commission for Cancer, 2010), there were 36 cases at T2 stage, 109 cases at T3 and 52 cases at T4; 117 cases with N0, 46 cases with N1 and 34 cases with N2. The sensitivity, specificity, positive predictive value and negative predictive value of CT for the detection of thyroid cartilage invasion were respectively 57%, 86%, 65% and 81%, and those of MRI were respectively 94%, 87%, 78% and 97%. Kappa values were 0.45 for CT and 0.77 for MRI in diagnosis of thyroid cartilage invasion, with statistically significant difference (χ(2)=6.78, P<0.05). Conclusion: MRI (FRFSE and SE-EPI DWI) has more advantages than CT in the diagnosis of thyroid cartilage invasion by laryngeal or hypopharyngeal cancer.

A large giant cell tumor of the larynx: case report and review of the literature

BACKGROUND

Giant cell tumors (GCTs) are typically found in the metaphyseal-epiphyseal area of long bones but can also occur in the head and neck region. GCT of the larynx is a rare entity with only 42 reported cases in the international literature. Furthermore, to the best of our knowledge this is the largest laryngeal GCT reported in the literature to date. GCT of the larynx can present with dysphonia, dyspnea, and/or dysphagia and should be considered in the differential diagnosis of a neck mass.

CASE PRESENTATION

This case report describes a giant cell tumor of the left thyroid cartilage in a 30-year-old man who initially presented with dysphonia and dysphagia. Computed tomography (CT) revealed a 5 × 5.7 cm mass centered on the left thyroid cartilage, which was further diagnosed by histopathology as giant cell tumour by open biopsy. The patient was counselled on treatment options and it was decided to proceed with a surgical approach. The patient consented to and successfully underwent a total laryngectomy (TL). Currently the patient has no evidence of disease at 13 months follow-up, has an optimal prosthetic voice, and is able to tolerate all textures of foods.

CONCLUSION

GCTs of the larynx have a good prognosis and can be treated successfully through complete resection of the tumor, negating the need for adjunctive therapy such as radiation, chemo or denosumab therapy.

Hemilaryngeal Microsomia: An Anatomic Variant

OBJECTIVES

This study aims to describe a congenital laryngeal structural variant, hemilaryngeal microsomia (HLM), and to correlate identification on physical examination with computerized tomography scan (CT) and laryngoscopy findings.

METHODS

The study was conducted at a tertiary care center. Six patients presenting with hoarseness were admitted to a tertiary care otolaryngology office. These patients had asymmetrical thyroid cartilage prominence on palpation during physical examination. A diagnosis of HLM was made. All patients underwent laryngostroboscopy and CT scan. Four control patients with normal thyroid cartilage anatomy on physical examination, CT, and stroboscopy results were included for comparison.

RESULTS

Disparities in thyroid cartilage angles correlated with documented physical examination findings for six out of six HLM patients. On CT scan, the average difference in left and right thyroid laminar angles was 30.2° ± 18.3° in HLM patients vs 4.00° ± 1.63° in control patients (P = 0.023). Strobosocopic findings also correlated with HLM. The arytenoid cartilage was anteriorly or medially displaced on the microsomic side in all six HLM patients. Three patients had anterior placement of the vocal process resulting in shortening of the vocal fold on the microsomic side of the larynx.

CONCLUSIONS

HLM is a congenital structural anomaly of the larynx that may be palpated on physical examination. HLM found on physical examination can be correlated with asymmetries found on CT scan and endoscopy. There is no evidence that the structural features of HLM were causally related to voice symptoms, but the findings on HLM may lead to misdiagnosis. A larger study is indicated to confirm laryngeal structural differences between patients with HLM on physical examination and the general population. Whether or not HLM affects clinical or surgical outcomes remains to be studied.

Lateral thyroid cartilage thyrotomy approach to an embedded paraglottic fishbone

Fishbones are of particular interest to otolaryngologists. Most fishbones can be removed transorally or via endoscopic guidance. Transcervical neck exploration is occasionally necessary, especially in cases of an embedded foreign body. Computed tomography is the most sensitive and specific imaging modality for identifying embedded fishbones. To our knowledge, this is the first reported case of a laryngeal foreign body embedded in the paraglottic space that was removed using an open approach via a lateral thyroid cartilage window.

Cyst-like change in the thyroid cartilage: A developmental variant in children

Neck sonography is frequently encountered on ultrasound lists in the paediatric patient population. Anecdotally, one of the most frequent clinical indications is the investigation of a neck lump. While performing an ultrasound of the neck, structures other than those routinely assessed, such as the thyroid cartilage and mandibular cortex also come into view. Occasionally, pathology in these structures is also encountered, albeit less frequently. The purpose of this case report and review is to illustrate the ultrasound, computed tomography and magnetic resonance imaging appearances of cyst-like changes in the thyroid cartilage that are encountered in children, particularly in early adolescence.

Is there a role for PET/CT parameters to differentiate thyroid cartilage invasion from penetration?

BACKGROUND

Assessment of thyroid cartilage invasion (tumor extension through inner cortex) and thyroid cartilage penetration (tumor involving both the inner and outer cortices of thyroid cartilage) may be challenging with CT (Computed Tomography) and MR imaging (Magnetic Resonance Imaging). Positron Emission Tomography/Computed Tomography (PET/CT) is a non invasive imaging modality that provides both anatomic and metabolic information. Quantitative data obtained from PET/CT, also known as PET/CT parameters, include maximum, mean or peak standardized uptake values (SUVmax, SUVmean, SUVpeak), metabolic tumor volume (MTV), total lesion glycolysis (TLG), standardized added metabolic activity (SAM) and normalized standardized added metabolic activity (NSAM). Our aim was to examine if FDG PET/CT parameters could differentiate thyroid cartilage invasion from penetration.

METHODS

50 patients who underwent PET/CT before laryngectomy for squamous cell carcinoma of the larynx, had SUVmax, SUVmean, SUVpeak, TLG, MTV, SAM and NSAM calculated on a dedicated workstation. Univariate and multivariate analysis was performed. ROC analysis was used to determine the ability of PET/CT parameters to predict pathologically proven thyroid cartilage invasion or penetration.

RESULTS

Of the 50 patients, 50% (25/50 patients) had history of prior radiation therapy. Among the previously irradiated group, 24% had thyroid cartilage invasion and penetration. 8% of the patients in this group had thyroid cartilage invasion only. Among the non-irradiated group, 76% had thyroid cartilage invasion and penetration, 8% had thyroid cartilage invasion without penetration. ROC analysis revealed that none of the PET/CT parameters had enough power to predict thyroid cartilage penetration, but TLG, MTV and SAM had enough power to predict thyroid cartilage invasion in non-irradiated patients. TLG, MTV, SAM and NSAM had enough power to predict thyroid cartilage invasion and penetration in irradiated group.

CONCLUSION

TLG, MTV and SAM have enough power to predict thyroid cartilage invasion and penetration in irradiated patients. PET/CT parameters do not have enough potential to differentiate thyroid cartilage invasion from penetration.

Extraosseous chondroma of anterior neck in pediatric patient

Extraosseous chondroma (EC) is uncommon soft tissue tumor composed of hyaline cartilage without connection to bone or periosteum. The frequent sites of EC are the hands and feet and rarely reported in the pediatric population and anterior neck lesion. We present an extremely rare case of anterior neck mass in a 5-year-old male who underwent total resection, with the final diagnosis of EC. The review of the literature showed that all cases of EC in anterior neck lesion have been found in young age and preoperative diagnosis was difficult.

Surface Landmarks do not Correspond to Exact Levels of the Cervical Spine: References According to the Sex, Age and Height

Objective

A general orientation along the cervical spine could be estimated by external landmarks, and it was useful, quick and less exposable to radiation, but, sometimes it gave reference confusion of target cervical level. The authors reviewed the corresponding between the neck external landmarks and cervical levels.

Methods

Totally 1,031 cervical lateral radiographs of different patients were reviewed in single university hospital. Its compositions were 534 of males and 497 females; 86 of second decades (10-19 years-old), 169 of third decades, 159 of fourth decades, 209 of fifth decades, 275 of sixth decades, and 133 of more than seventh decades (>60 years-old). Reference external landmarks (mandible, hyoid bone, thyroid cartilage, and cricothyroid membrane) with compounding factors were reviewed.

Results

The reference levels of cervical landmarks were C2.13 with mandible angle, C3.54 with hyoid bone, C5.12 with thyroid cartilage, and C6.01 with cricothyroid membrane. The reference levels of cervical landmarks were differently observed by sex, age, and somatometric measurement (height) accordingly mandible angle from C1 to C3, hyoid bone from disc level of C2 and C3 to C5, thyroid cartilage from disc level of C3 and C4 to C7, and cricothyroid membrane from C4 to disc level of C7 and T1.

Conclusion

Surface landmarks only provide general reference points, but not correspond to exact levels of the cervical spine. Intraoperative fluoroscopy ensures a more precise placement to the targeted cervical level.

Anatomical characterisation of the cricothyroid membrane in females of childbearing age using computed tomography

BACKGROUND

In the event of failure to secure the airway by conventional means, it may be necessary to perform invasive airway access via the cricothyroid membrane. No studies have addressed anatomy of this structure in the obstetric population. We aimed to review the anatomical variation of this structure in a population of childbearing age.

METHODS

We searched the radiology database for computed tomography studies of the neck performed in a 13-month period in consecutive patients aged 15-55 years. Studies on 18 females and 22 males were reviewed. Male patients were included for comparison. Data were reconstructed using a high spatial frequency algorithm to optimise spatial resolution. Five parameters were measured: distance from the skin to the membrane, maximum midline height of the membrane in the vertical plane, maximum transverse diameter of the membrane, neck diameter and cartilaginous calcification.

RESULTS

The distance (mean range) from skin to the membrane was similar in females and males (16.2 [3-33] vs. 13.9 [3-37] mm, P = 0.42). The vertical height (9.9 [7-17] vs. 11.4 [8-15] mm, P = 0.04) and maximum width of the membrane (14.5 [10-17] mm vs. 12.5 [10-15] mm, P < 0.01) were greater in males. Cartilaginous calcification was low and did not differ between genders.

CONCLUSIONS

The cricothyroid membrane is not necessarily a superficial structure and consequently may be difficult to palpate. The smallest dimensions of the membrane indicate that smaller than recommended cricothyroidotomy devices may be required in some patients as the external diameter of commercial trocar devices and tracheal tubes may exceed 7 mm.

Hypopharyngeal Wall Exposure within the Surgical Field : The Role of Axial Rotation of the Thyroid Cartilage during Anterior Cervical Surgery

OBJECTIVE

Esophageal/hypopharyngeal injury can be a disastrous complication of anterior cervical surgery. The amount of hypopharyngeal wall exposure within the surgical field has not been studied. The objective of this study is to evaluate the chance of hypopharyngeal wall exposure by measuring the amount of axial rotation of the thyroid cartilage (ARTC) and posterior projection of the hypopharynx (PPH).

METHODS

The study was prospectively designed using intraoperative ultrasonography. We measured the amount of ARTC in 27 cases. The amount of posterior projection of the hypopharynx (PPH) also was measured on pre-operative CT and compared at three different levels; the superior border of the thyroid cartilage (SBTC), cricoarytenoid joint and tip of inferior horn of the thyroid cartilage (TIHTC). The presence of air density was also checked on the same levels.

RESULTS

The angle of ARTC ranged from -6.9° to 29.7°, with no statistical difference between the upper and lower cervical group. The amount of PPH was increased caudally. Air densities were observed in 26 cases at the SBTC, but none at the TIHTC.

CONCLUSION

Within the confines of the thyroid cartilage, surgeons are required to pay more attention to the status of hypopharynx/esophagus near the inferior horn of the thyroid cartilage. The hypopharynx/esophagus at the TIHTC is more likely to be exposed than at the upper and middle part of the thyroid cartilage, which may increase the risk of injury by pressure. Surgeons should be aware of the fact that the visceral component at C6-T1 surgeries also rotates as much as when the thyroid cartilage is engaged with a retractor. The esophagus at lower cervical levels warrants more careful retraction because it is not protected by the thyroid cartilage.

Comparative Analysis of Efficiency of Injection Laryngoplasty Technique for with or without Neck Treatment Patients: A Transcartilaginous Approach Versus the Cricothyroid Approach

Objectives

These days, the main injection laryngoplasty technique is cricothyroid (CT) approach. However, patients who have previously undergone other neck treatments, such as thyroidectomy or neck dissection have distorted anatomical landmark makes this approach more difficult. The aim of this study is to determined the efficiency of transcartilaginous (TC) approah as compared with CT approach for unilateral vocal fold paralysis patients, especially for previously neck treated patients.

Methods

From March 2005 to February 2008, 137 consecutive injection laryngoplasties were performed in patients with unilateral glottic insufficiency. Percutaneous injection was performed under local anesthesia into the vocalis muscle, using disposable 25 G 4 cm long needles through the cricothyroid membrane or directly through the thyroid cartilage. Of the 137 patients, 124 completed acoustic, perceptual, stroboscopic, and subjective evaluations prior to the injection and at 3 months after the injection.

Results

In the 124 patients, the CT and TC approaches were used in 94 and 30 patients, respectively. Acoustic and perceptual parameters (GRBAS, MPT, jitter, shimmer), voice handicap index, and grades of mucosal waves and glottic closure were significantly improved after the injection in both the CT and TC groups (P<0.05). Only two patients (6.6%) had penetration difficulties, because of ossification of the thyroid cartilage. The overall success rates of the CT and TC approaches were 86.2%, 93.3%, respectively. However, the success rate of the TC approach in patients who had previously undergone neck treatments was significantly higher than that of the CT approach (100% vs. 65% P<0.05).

Conclusion

Based on the preliminary results of this trial, injection laryngoplasty using a TC approach was an effective alternative to the CT approach, especially in patients who had previously undergone neck surgeries.