Stanley Yung-Chuan Liu

Peripheral endothelin A receptor antagonism attenuates carcinoma-induced pain.

In this study we investigated the role of endothelin‐1 (ET‐1) and its peripheral receptor (ET‐A) in carcinoma‐induced pain in a mouse cancer pain model. Tumors were induced in the hind paw of female mice by local injection of cells derived from a human oral squamous cell carcinoma (SCC). Significant pain, as indicated by reduction in withdrawal thresholds in response to mechanical stimulation, began at four days after SCC inoculation and lasted to 28 days, the last day of measurement. Intra‐tumor expression of both ET‐1 mRNA and ET‐1 protein were significantly upregulated compared to normal tissue, and local administration of the ET‐A receptor selective antagonist, BQ‐123 (100μM) significantly elevated withdrawal thresholds, indicating the induction of an antinociceptive effect. These findings support the suggestion that ET‐1 and ET‐A receptors contribute to the severity of carcinoma‐induced soft tissue cancer pain.

Inferior turbinate classification system, grades 1 to 4: development and validation study.

To develop a validated inferior turbinate grading scale.

Epiglottis collapse in adult obstructive sleep apnea: A systematic review.

To systematically review the international literature evaluating the role of the epiglottis in snoring and obstructive sleep apnea and to explore possible treatment options available.

Lateral pharyngeal wall collapse associated with hypoxemia in obstructive sleep apnea

Review drug‐induced sleep endoscopy (DISE) findings and correlate the patterns of airway collapse with body mass index (BMI) and objective sleep study respiratory variables, with particular emphasis on oxygen desaturation variables.

Lateral Pharyngeal Wall Tension After Maxillomandibular Advancement for Obstructive Sleep Apnea Is a Marker for Surgical Success: Observations From Drug-Induced Sleep Endoscopy

PURPOSE The efficacy of maxillomandibular advancement (MMA) for obstructive sleep apnea (OSA) with anatomic airway changes has previously been studied using static imaging and endoscopy in awake subjects. The aim of the present study was to use drug-induced sleep endoscopy (DISE) to evaluate the dynamic upper airway changes in sleeping subjects before and after MMA and their association with the surgical outcome. PATIENTS AND METHODS This was a retrospective cohort study of subjects with OSA who had undergone MMA at the Stanford University Sleep Surgery Division from July 2013 to July 2014. The subjects were included if perioperative polysomnography and DISE had been performed. The predictor variable was the perioperative DISE velum-oropharynx-tongue-epiglottis score. The outcome variables were the apnea-hypopnea index (AHI), oxygen-desaturation index (ODI), and Epworth Sleepiness Scale (ESS). A subgroup analysis was performed for the subjects who had undergone primary and secondary MMA. The statistical analyses included Cronbachs α coefficient, the McNemar test, and the independent Student t test. The P value was set at <.01. RESULTS A total of 16 subjects (15 males, 1 female) were included in the present study, with an average age of 47 ± 10.9 years and body mass index of 29.4 ± 5.1 kg/m(2). Significant post-MMA decreases were found in the AHI (from 59.8 ± 25.6 to 9.3 ± 7.1 events/hr) and ODI (from 45 ± 29.7 to 5.7 ± 4.1 events/hr; P < .001). Greater improvement in the AHI occurred in the primary MMA group (P = .022). The post-MMA change in airway collapse was most significant at the lateral pharyngeal wall (P = .001). The subjects with the most improvement in lateral pharyngeal wall collapsibility demonstrated the largest changes in the AHI (from 60.0 ± 25.6 events/hr to 7.5 ± 3.4 events/hr) and ODI (from 46.7 ± 29.8 to 5.3 ± 2 events/hr; P = .002). CONCLUSIONS Using DISE, we observed that after MMA, the greatest reduction in upper airway collapsibility is seen at the lateral pharyngeal wall of the oropharynx, followed by the velum, and then the tongue base. The stability of the lateral pharyngeal wall is a marker of surgical success after MMA using the AHI, ODI, and ESS.

Efficacy of Maxillomandibular Advancement Examined with Drug-Induced Sleep Endoscopy and Computational Fluid Dynamics Airflow Modeling.

Objectives To use drug-induced sedation endoscopy (DISE) and computational fluid dynamics (CFD) modeling to study dynamic airway and airflow changes after maxillomandibular advancement (MMA), and how the changes correlate with surgical success based on polysomnography parameters. Study Design Retrospective cohort study. Setting University medical center. Methods DISE was rated with the VOTE (velum, oropharynx, tongue, epiglottis) classification, and CFD was used to model airflow velocity and negative pressure exerted on pharyngeal wall. Changes in VOTE score by site and CFD measurements were correlated with perioperative polysomnography outcomes of apnea-hypopnea index (AHI), apnea index (AI), oxygenation desaturation index (ODI), and lowest oxygen saturation. Results After MMA, 20 subjects (17 males, 3 females) with a mean age of 44 ± 12 years and body mass index of 27.4 ± 4.6 kg/m2 showed mean decreases in AHI (53.6 ± 26.6 to 9.5 ± 7.4 events/h) and ODI (38.7 ± 30.3 to 8.1 ± 9.2 events/h; P < .001). Improvement in lateral pharyngeal wall collapse during DISE based on VOTE score correlated with the most decrease in AHI (60.0 ± 25.6 to 7.5 ± 3.4 events/h) and ODI (46.7 ± 29.8 to 5.3 ± 2 events/h; P = .002). CFD modeling showed significant positive Pearson correlations between reduction of retropalatal airflow velocity and AHI (r = 0.617, P = .04) and ODI (r = 0.773, P = .005). Conclusion AHI and ODI improvement after MMA is best correlated with (1) decreased retropalatal airflow velocity modeled by CFD and (2) increased lateral pharyngeal wall stability based on VOTE scoring from DISE.

Identifying risk factors for postoperative cardiovascular and respiratory complications after major oral cancer surgery.

Surgical resection of oral cancer can be associated with significant postoperative cardiovascular and respiratory complications that require more sensitive predictors.

Hyoid surgery alone for obstructive sleep apnea: A systematic review and meta-analysis.

The primary objective was to determine if sleep study variables (e.g., apnea‐hypopnea index [AHI] and lowest oxygen saturation) and quantitative sleepiness data improve following isolated hyoid surgery for obstructive sleep apnea (OSA).

Static craniofacial measurements and dynamic airway collapse patterns associated with severe obstructive sleep apnoea: a sleep MRI study.

Using sleep MRI, we aimed to identify static craniofacial measurements and dynamic upper airway collapse patterns associated with severe obstructive sleep apnoea (OSA) during natural sleep in age and BMI‐matched patients.

Brain abscess potentially secondary to odontogenic infection: case report

Odontogenic infections are rarely implicated in the causes of brain abscess formation. As such, there are very few reports of brain abscesses secondary to odontogenic infections in the literature. This is due partly to the relative rarity of brain abscesses but also to the difficulty in matching the causative organisms of a brain abscess to an odontogenic source. The authors report a case of a 50-year-old woman whose brain abscess may potentially have been secondary to an odontogenic infection. The patients early diagnosis, supported by imaging and microbiologic assessment, along with early minicraniotomy and extraction of infected dentition followed by a course of cephalosporins and metronidazole, contributed to a successful outcome.