Nasal Obstruction as a Potential Factor Contributing to Hypoxemia in Obstructive Sleep Apnea.

PURPOSE: This study aimed to evaluate the correlation between nasal resistance and oxygen desaturation to better elucidate the role of nasal obstruction in the pathophysiology of obstructive sleep apnea (OSA). PATIENTS AND METHODS: Eighty-eight OSA patients aged between 22 and 77 years were enrolled in this study. Nasal resistance was measured at pressures of 75, 150, and 300 Pa, with the patients first in the seated position than in the supine position. Relationships between the oximetric variables and nasal resistance in the seated and supine positions were analyzed. RESULTS: From seated to supine position, a statistically significant increase in nasal resistance was observed at pressures of 75 and 150 Pa (p=0.001 and p=0.006, respectively). Significant positive correlations were noted between nasal resistance in the supine position at 75 Pa (SupineNR75) and oximetry variables, including oxygen desaturation index (ODI, p=0.015) and the percentage of total time with oxygen saturation level lower than 90% (T < 90%, p=0.012). However, significant positive correlations existed only in moderate to severe OSA when the study group was further divided into two subgroups (mild vs moderate to severe OSA). Body mass index (ß = 0.476, p<0.001) and SupineNR75 (ß = 0.303, p=0.004) were identified as independent predictors for increased ODI. CONCLUSION: Nasal resistance in the supine position measured at 75 Pa significantly correlated with the severity of oxygen desaturation. Therefore, nasal obstruction may play an important role in the pathophysiology of hypoxemia in OSA patients, especially in patients with moderate to severe OSA.

Dynamic tongue base thickness measured by drug-induced sleep ultrasonography in patients with obstructive sleep apnea.

BACKGROUND/PURPOSE: The aim of this study was to determine the value of drug-induced sleep ultrasonography (DISU) for evaluating tongue base thickness (TBT) from the awake state to drug-induced sleep, to further understand the impact of dynamic changes in TBT in obstructive sleep apnoea (OSA) patients. METHODS: From May 2017 to May 2018, thirty patients with OSA were prospectively recruited. Sleep was induced with propofol via use of a target-controlled infusion (TCI) system. The depth of sedation was monitored by the bispectral (BIS) index with BIS levels ranging from 50 to 70. The dynamic change in the tongue base from the awake state to drug-induced sleep was recorded. The correlation between TBT in the awake state and in drug-induced sleep with OSA severity was analysed. RESULTS: The mean TBT in drug-induced sleep was significantly greater than that in the awake state (66.2 ± 4.8 mm vs 61.6 ± 4.6 mm, P < 0.001). TBT in drug-induced sleep was more correlated with AHI compared to TBT in the awake state (r = 0.50 vs r = 0.40). This study showed that TBT in drug-induced sleep had the largest AUC (Area Under the Curve) in the ROC (Receiver Operating Characteristics) analysis (0.875), providing a cut-off point of 63.20 mm with 95% sensitivity for diagnosis of moderate versus severe OSA. CONCLUSION: Our findings validate the use of DISU in objectively assessing the tongue base collapse in OSA patients. It provides a convenient and non-invasive way to evaluate the upper airway changes in OSA patients in the future.

The correlation between drug-induced sleep endoscopy findings and severity of obstructive sleep apnea.

OBJECTIVE: This study aimed to assess the relationship between anthropometric data, drug-induced sleep endoscopy (DISE) findings, and severity of obstructive sleep apnea (OSA). METHODS: From August 2016 to August 2017, a total of 147 surgically naïve adult patients with OSA underwent DISE. Factors that were analyzed included anthropometric data and DISE findings. RESULTS: When anthropometric data and DISE findings were analyzed with AHI by univariate analysis, the results showed that Epworth Sleepiness Scale (ESS), body mass index (BMI), neck circumference, concentric collapse of the velum, lateral oropharyngeal collapse, and anterior-posterior collapse of the tongue base were considered potentially independent predictors (p = 0.024, p < 0 .001, p < 0 .001, p < 0.001, p < 0.001, p < 0 .001, respectively, by Spearman correlation). When all important factors were evaluated in a stepwise multiple linear regression analysis, BMI, lateral oropharyngeal collapse, and anterior-posterior collapse of the tongue base were identified as significant predictors for the severity of OSA. The final model was listed as below: AHI score = 2.19 BMI + 7.56 Oropharynx/Lateral degree + 8.23 Tongue base/ Anterior-Posterior degree - 40.59. CONCLUSION: By analyzing anthropometric data and DISE findings with AHI score, the results indicated that BMI, lateral oropharyngeal collapse, and anterior-posterior collapse of the tongue base were important factors associated with the severity of OSA.

Effect of back-up head-elevated position during drug-induced sleep endoscopy in obstructive sleep apnea patients.

PURPOSE: This study aimed to evaluate the difference of upper airway collapse between the back-up head-elevated position (a 45° upward inclination) and supine position to better elucidate the role of back-up head-elevated position in reductions of obstructive sleep apnea (OSA) severity. METHODS: From August 2016 to May 2019, 198 patients aged between 18 and 70 years were recruited in this study prospectively. Drug-induced sleep endoscopy (DISE) findings were recorded with the patients first placed in the supine position then into the back-up head-elevated position with a 45° upward inclination. RESULTS: From the supine to back-up head-elevated position, a significant decrease in the severity of collapse was observed in velum anteroposterior collapse and velum concentric collapse (p < 0.001 and p < 0.001, respectively), which was more predominant in patients with mild OSA than in patients with moderate to severe OSA. On the other hand, there was no significant improvement of any other collapse at the level of oropharynx, tongue base, or epiglottis when the position was shifted from the supine into back-up head-elevated position. CONCLUSIONS: The back-up head-elevated position with a 45° upward inclination improved upper airway obstruction during DISE in velum anteroposterior collapse and velum concentric collapse. The proportion of patients with amelioration of upper airway collapse was much higher in patients with mild OSA than in patients with moderate to severe OSA. The back-up head-elevated position may be a reasonable alternative to traditional positional therapy for certain subgroups of patients with OSA.

Role of drug-induced sleep endoscopy in evaluation of positional vs non-positional OSA.

BACKGROUND: The study aimed to evaluate the anatomical differences between positional and non-positional OSA, and to identify the potential predictors for distinguishing between these two types of OSA. METHODS: A cross-sectional study of 230 consecutive patients with OSA undergoing DISE (Drug-induced Sleep Endoscopy) was carried out at a tertiary academic medical center. The factors correlating with positional and non-positional OSA were analyzed, including clinical characteristics, polysomnography data, and DISE findings. RESULTS: Univariate analysis revealed that non-positional dependency was correlated with a higher BMI (p < 0.001), neck circumference (p < 0.001), modified Mallampati score (p = 0.003), AHI (p < 0.001), degree of velum concentric collapse (p = 0.004), degree of oropharyngeal lateral wall collapse (p < 0.001), and degree of tongue base anteroposterior collapse (p = 0.004). Multivariate analysis revealed that oropharyngeal lateral wall collapse (OR = 1.90, p = 0.027) was the only anatomical factor significantly predicted non-positional dependency in OSA patients. AHI (OR = 1.04, p < 0.001), although significant, made only a marginal contribution to the prediction of non-positional dependency. CONCLUSIONS: Oropharyngeal lateral wall collapse was identified as the only anatomical predictor for non-positional dependency in OSA patients. Therefore, further treatment modalities should address the distinct anatomical trait between positional and non-positional OSA.

The Relationship Between Modified Mallampati Score, Müller's Maneuver and Drug-Induced Sleep Endoscopy Regarding Retrolingual Obstruction.

OBJECTIVES: This study explored the correlation between clinical explorations, including modified Mallampati score and Müller's maneuver, with drug-induced sleep endoscopy (DISE) findings regarding retrolingual obstruction. METHODS: One hundred forty-two obstructive sleep apnea patients were enrolled in this prospective study. All of the patients received clinical explorations including modified Mallampati scoring and Müller's maneuver in the clinic. Drug-induced sleep endoscopy was further evaluated in the operating room. RESULTS: A significant relationship was noted between modified Mallampati score and retrolingual obstruction during DISE. In contrast, no significant relationship was noted between Müller's maneuver and DISE findings regarding retrolingual obstruction. CONCLUSIONS: A significant discrepancy existed between retrolingual airway collapse evaluated by modified Mallampati score and Müller's maneuver. Modified Mallampati score is more correlated with DISE regarding retrolingual obstruction compared to Müller's maneuver. It should therefore be used as an initial evaluation of retrolingual obstruction when DISE is unavailable.

The predictive value of drug-induced sleep endoscopy for CPAP titration in OSA patients.

PURPOSE: The aim of this study was to identify possible upper airway obstructions causing a higher continuous positive airway pressure (CPAP) titration level, utilizing drug-induced sleep endoscopy (DISE). METHODS: A total of 76 patients with obstructive sleep apnea (OSA) underwent CPAP titration and DISE. DISE findings were recorded using the VOTE classification system. Polysomnographic (PSG) data, anthropometric variables, and patterns of airway collapse during DISE were analyzed with CPAP titration levels. RESULTS: A significant association was found between the CPAP titration level and BMI, oxygen desaturation index (ODI), apnea-hypopnea index (AHI), and neck circumference (NC) (P < 0.001, P < 0.001, P < 0.001, and P < 0.001, respectively, by Spearman correlation). Patients with concentric collapse of the velum or lateral oropharyngeal collapse were associated with a significantly higher CPAP titration level (P < 0.001 and P = 0.043, respectively, by nonparametric Mann-Whitney U test; P < 0.001 and P = 0.004, respectively, by Spearman correlation). No significant association was found between the CPAP titration level and any other collapse at the tongue base or epiglottis. CONCLUSIONS: By analyzing PSG data, anthropometric variables, and DISE results with CPAP titration levels, we can better understand possible mechanisms resulting in a higher CPAP titration level. We believe that the role of DISE can be expanded as a tool to identify the possible anatomical structures that may be corrected by oral appliance therapy or surgical intervention to improve CPAP compliance.

Drug-induced sleep endoscopy in children with Prader-Willi syndrome.

PURPOSE: Review drug-induced sleep endoscopy (DISE) findings in children with Prader-Willi syndrome (PWS) and correlate the patterns of airway collapse with apnea-hypopnea index (AHI) and body mass index (BMI). METHODS: A total of nine children with PWS underwent DISE. DISE findings were recorded using the VOTE classification system. The relationship between different patterns of airway collapse with AHI and BMI was analyzed. RESULTS: The majority of children with PWS were found to have multilevel obstruction (six out of nine children, 66.6 %). The velum was the most common site of obstruction (nine out of nine children, 100 %). All of the patients had positional obstructive sleep apnea (OSA). Patients with partial or complete anterior-posterior tongue base collapse were associated with a significantly higher AHI (P = 0.016) compared to patients with no anterior-posterior tongue base collapse. Apart from tongue base collapse, no other patterns of airway collapse showed a consistent association with AHI in our results. No patterns of airway collapse showed a significant association with BMI in our study. CONCLUSIONS: In our study, partial or complete anterior-posterior tongue base collapse was associated with higher AHI values in children with PWS. Therefore, careful attention should be addressed to the management of tongue base collapse. Positional therapy could be a potential treatment for patients with PWS since it may alleviate the severity of tongue base collapse.

Resected tumours of the sublingual gland: 15 years' experience.

Sublingual gland tumours are rare, and we have evaluated the clinical features and prognosis of patients treated at a tertiary medical centre in eastern Taiwan. We retrospectively reviewed the cases of nine patients with sublingual gland tumours that were resected from December 1993 to November 2008, four of whom were men and five women. The median (range) age at diagnosis was 52 (39-63) years. Seven had malignant tumours, of which adenoid cystic carcinoma was the most common. All patients with malignant tumours had neck dissections, and four had cervical lymph node metastases. The incidence of lymph node metastases was much higher in patients with advanced primary tumours (T1/2 compared with T3/4: one out of three compared with three out of four). All patients with malignant tumours were given adjuvant radiotherapy. There were no local failures. One patient had regional recurrence in the neck and had a successful further resection. Three patients developed distant metastases, and two died during the follow-up period. Our results suggest that radical resection with postoperative radiotherapy offers adequate local and regional control for malignant sublingual gland tumours. Neck dissection is beneficial, especially for T3/4 disease.

Nerve branches to the posterior cricoarytenoid muscle may complicate the laryngeal reinnervation procedure.

OBJECTIVES/HYPOTHESIS: To better understand the reason for the low success rate of posterior cricoarytenoid (PCA) muscle reinnervation, we attempted to identify the communicating branches that may exist between the nerve branch to the PCA muscle and the other laryngeal adductors in addition to the interarytenoid (IA) muscle. STUDY DESIGN: Quantitative histological assessment. METHODS: Twenty human hemilarynges from patients with laryngeal or hypopharyngeal cancer were obtained after surgery and stained with Sihler's stain, which rendered the muscle translucent while counterstaining the neuroanatomy of the recurrent laryngeal nerve (RLN) inside the larynges. RESULTS: The nerve supply to the PCA muscle was separated into two main branches. One upper branch supplied the horizontal compartment, and the lower branch supplied the vertical/oblique compartment. In 14 specimens, two nerve branches to the PCA muscle arose separately from the RLN. In six specimens, one single main branch arose from the RLN and immediately ramified into two secondary branches. In all specimens except one, the nerve branch to the horizontal compartment was connected to the IA muscle. However, no communicating branches were observed between the nerve to the PCA muscle and the other laryngeal adductors. No anastomosis between nerve branches to the horizontal and vertical/oblique compartments or other variations of nerve distribution were observed. CONCLUSIONS: The communicating branches between the nerve branches to the PCA muscle and the IA muscle may be the only branch, complicating the reinnervation procedure. More investigations are needed to identify variations in the terminal branch distribution from the RLN. LEVEL OF EVIDENCE: NA.

Suture lateralization in patients with bilateral vocal fold paralysis.

OBJECTIVES: To introduce a simplified suture lateralization (SL) technique to treat patients with bilateral vocal fold paralysis (BVFP). STUDY DESIGN: A retrospective study of surgical procedures by manual chart review. METHODS: The proposed endoscopic SL procedure was used for 20 patients operated on for BVFP between 2007 and 2013, with three attempts to remove a tracheostomy tube and 17 attempts to resolve the dyspnea. An adjustment procedure was also used to correct any excessive lateralization according to the individual's clinical symptoms, such as intolerable aspiration after SL in elderly patients and excessive breathiness of voice in socially active patients. St George's respiratory questionnaire was used to subjectively evaluate the efficacy of lateralization of vocal folds. Pulmonary function test with flow-volume loop was used to objectively evaluate the improvement of BVFP-related upper airway obstruction after surgery. Phonatory ability tests were also used to evaluate the degree of deterioration of voice quality. RESULT: Twenty patients underwent 22 episodes of SL. Two adjustment procedures were performed to correct excessive breathiness of voice or intolerable aspiration. Respiration was adequate in all 19 patients without artificial airways. Voice quality was socially acceptable in 19 of the patients and even equal to preoperative voice quality in 14 of them. Temporary mild aspiration occurred in 18 patients only in the first few days after the procedure. One decannulation failure and refusing adjustment procedure occurred in one elderly patient. All the patients were followed up for surgical outcomes for at least 9 and 33 months on average. CONCLUSION: SL is a simple, reversible, and minimally invasive reconstructive procedure for patients with BVFP. Our study supported its applicability for selected patients.

Predictors of locoregional recurrence in early stage oral cavity cancer with free surgical margins.

Locoregional recurrence in patients with early stage oral cavity squamous cell carcinoma (ESOSCC) after surgery remains a problem and can affect their survival. We sought to identify new high-risk factors in these patients, who need further adjuvant therapy. We retrospectively reviewed records for 148 patients who underwent surgery for ESOSCC between 2002 and 2006 with negative surgical margins. The primary endpoint was locoregional recurrence. Recurrence-free survival (RFS) and overall survival (OS) were calculated by the Kaplan-Meier method. Univariate and multivariate analyses were used to identify independent predictors of locoregional recurrence. All patients were grouped into the low- and high-risk groups according to the odds ratios (OR) of the predictors. Recurrence rates of the low- and high-risk groups were then predicted. Recurrence was observed in 17 of 148 (11.5%) patients at the end of this study. None of the patients received postoperative radiotherapy or chemotherapy. At 3 years, the RFS rate was 89.7% and the OS rate at 3 years was 84.1%. Univariate analysis of the RFS revealed three significant prognostic factors: lymphovascular permeation (LVP, p<0.001), perineural infiltration (PNI, p=0.08), and non-T4 muscular invasion (non-T4MI, p<0.005). Multivariate analysis demonstrated that LVP (p=0.007, OR=10.7) and non-T4 MI (p=0.001, OR=8.347) were independent predictors. The recurrence rate was 1.96% in patients without LVP or non-T4MI, and it increased to 26.47% in patients with non-T4MI, to 50% in patients with LVP, and to 50% in patients with both. According to the status of LVP and non-T4MI, patients were divided into two groups: low-risk (no factors present) and high-risk (one or both factors present) groups. The 2-year RFS was lower in the high-risk group (84.13%) than in the low-risk group (93.91%); the 3-year RFS was also lower in the high-risk group (70.49%) than in the low-risk group (91.99%) (p=0.008). Subgroup analysis revealed that elective neck dissections did not affect the outcome or change the pattern of failure. For patients with elective neck dissections, the RFS was lower in the high-risk group than in the low-risk group (p=0.03). In ESOSCC (pT1-2N0), LVP and non-T4MI significantly increased the recurrence rate. The presence of one or both factors (LVP and/or non-T4MI) should be considered as a high-risk condition for locoregional recurrence, and adjuvant therapy is needed in such cases.

Surgical outcome in patients with oral verrucous carcinoma: long-term follow-up in an endemic betel quid chewing area.

BACKGROUND/AIMS: To evaluate the clinical features and prognosis of patients with oral verrucous carcinoma (OVC) in an endemic betel quid chewing area. METHODS: A retrospective review was conducted in 39 patients with OVC treated surgically from 1991 to 2002. RESULTS: Thirty-seven patients (94.9%) were male. The median age at diagnosis was 53.8 years. All patients had been exposed to betel quid, cigarette smoking, and/or alcohol. The most common site of tumor origin was the buccal mucosa (64.1%). The tumor control rate was 97.4% after the first surgical procedure. Second/multiple primary tumors (SPTs/MPTs) were found in 21 patients. There were 13 deaths during the follow-up period, with SPTs/MPTs being the most common cause. The cancer-specific survival rate was 89.1% at 5 years, but continued to decrease thereafter. CONCLUSION: Surgery was effective for controlling OVC. However, long-term follow-up was necessary because of the high incidence of SPTs/MPTs and its impact on patient survival.

Factors affecting the bacteriology of deep neck infection: a retrospective study of 128 patients.

CONCLUSIONS: Broad-spectrum antibiotics are advocated for treating deep neck infection. Anaerobic coverage is necessary, especially in odontogenic cases. The presence of diabetes, infection of the parotid space and an obvious odontogenic source of infection can aid in determining the causative organisms. OBJECTIVES: This study aimed to analyze the bacteriology in deep neck infections and identify the factors that influenced the causative pathogens. MATERIALS AND METHODS: The records of 212 patients who were diagnosed as having deep neck infections at the National Taiwan University Hospital between 1997 and 2003 were reviewed; 128 patients with bacterial isolation from their pus cultures were enrolled. RESULTS: The cultures of 46 patients (35.9%) were polymicrobial. Viridans Streptococcus was the most commonly isolated organism (38.3%), followed by Klebsiella pneumoniae (32.0%) and Peptostreptococcus (17.2%). The most common organism in 44 diabetic patients was K. pneumoniae (54.5%), versus viridans streptococcus (48.8%) in 84 nondiabetic patients. In patients with dental sources of infections, the culture rate of anaerobes was 59.3%; in upper airway infections and other sources of infections they were 22.7% and 21.5%, respectively (Chi(2) test, p = 0.0008). The differences in age, sex, and climate did not show any significant changes in the common causative pathogens. Common pathogens in the infection of parapharyngeal, submandibular, and extended spaces were the same as viridans streptococcus, but in the parotid space K. pneumoniae was the most common pathogen.

Deep neck infection in diabetic patients: comparison of clinical picture and outcomes with nondiabetic patients.

OBJECTIVE: To compare the difference in the clinical picture and outcomes between diabetic and nondiabetic patients with deep neck infections. STUDY DESIGN AND SETTING: We retrospectively reviewed the records of patients who were diagnosed with deep neck infections and who received treatment at the Department of Otolaryngology of National Taiwan University Hospital between 1997 and 2002. One hundred eighty-five patients were included in our study. Fifty-six patients with diabetes mellitus were enrolled for further analysis (diabetic group) and compared with the other 129 patients without diabetes mellitus (nondiabetic group) in demography, etiology, bacteriology, treatment, duration of hospital stay, complications, and outcome. RESULTS: The parapharyngeal space was the space most commonly involved in both the diabetic (33.9%) and nondiabetic groups (40.3%). Odontogenic infections and upper airway infections were the 2 leading causes of deep neck infection in diabetic and nondiabetic groups. Streptococcus viridans is the most commonly isolated organism in the nondiabetic group (43.7%). However, the most common organism in the diabetic group was Klebsiella pneumoniae (56.1%). There were 89.3% of diabetic patients, versus 71.3% of nondiabetic patients, with abscess formation ( P = 0.0136). Surgical drainage was performed more frequently in the diabetic group than in the nondiabetic group (86.0% versus 65.2%, P = 0.0142). In comparison with the nondiabetic group, the diabetic group tended to have older mean age (57.2 y versus 46.2 y, P = 0.0007), longer duration of hospital stay (19.7 days versus 10.2 days, P < 0.0001), more frequent complications (33.9% versus 8.5%, P < 0.0001), and more frequent tracheostomy or intubation (19.6% versus 6.2%, P = 0.0123). CONCLUSIONS: Patients with diabetes mellitus are susceptible to deep neck infection. We should pay more attention when dealing with deep neck infections in patients with diabetes mellitus because those patients tend to have complications more frequently and a longer duration of hospital stay. Empirical antibiotics should cover K. pneumoniae in patients with deep neck infection who have diabetes mellitus.

Deep neck infection: analysis of 185 cases.

PURPOSE: This study reviews our experience with deep neck infections and tries to identify the predisposing factors of life-threatening complications. METHODS: A retrospective review was conducted of patients who were diagnosed as having deep neck infections in the Department of Otolaryngology at National Taiwan University Hospital from 1997 to 2002. Their demographics etiology, associated systemic diseases, bacteriology, radiology, treatment, duration of hospitalization, complications, and outcomes were reviewed. The attributing factors to deep neck infections, such as the age and systemic diseases of patients, were also analyzed. RESULTS: One hundred eighty-five charts were recorded; 109 (58.9%) were men, and 76 (41.1%) were women, with a mean age of 49.5 +/- 20.5 years. Ninety-seven (52.4%) of the patients were older than 50 years old. There were 63 patients (34.1%) who had associated systemic diseases, with 88.9% (56/63) of those having diabetes mellitus (DM). The parapharyngeal space (38.4%) was the most commonly involved space. Odontogenic infections and upper airway infections were the two most common causes of deep neck infections (53.2% and 30.5% of the known causes). Streptococcus viridans and Klebsiella pneumoniae were the most common organisms (33.9%, 33.9%) identified through pus cultures. K. pneumoniae was also the most common infective organism (56.1%) in patients with DM. Of the abscess group (142 patients), 103 patients (72.5%) underwent surgical drainages. Thirty patients (16.2%) had major complications during admission, and among them, 18 patients received tracheostomies. Those patients with underlying systemic diseases or complications or who received tracheostomy tended to have a longer hospital stay and were older. There were three deaths (mortality rate, 1.6%). All had an underlying systemic disease and were older than 72 years of age. CONCLUSIONS: When dealing with deep neck infections in a high-risk group (older patients with DM or other underlying systemic diseases) in the clinic, more attention should be paid to the prevention of complications and even the possibility of death. Early surgical drainage remains the main method of treating deep neck abscesses. Therapeutic needle aspiration and conservative medical treatment are effective in selective cases such as those with minimal abscess formation.