Dr. Sung is a laryngologist in the Department of Otolaryngology — Head & Neck Surgery who specializes in voice, swallowing and airway disorders, and is also the Residency Program Director.

Dr. Sung graduated from Harvey Mudd College in Claremont, CA with a bachelor’s of science degree in chemistry with a minor in music. He earned a master’s of science degree in organic chemistry from the University of Pennsylvania. He attended the State University of New York – Downstate Medical Center and obtained his MD in 2004.

He completed his internship in general surgery at Mt. Sinai School of Medicine in New York City in 2005. He continued at Mt. Sinai to finish his residency in otolaryngology – head & neck surgery in 2009. Following residency, he completed a fellowship in laryngology at Harvard Medical School – Massachusetts Eye and Ear Infirmary with Ramon A. Franco, Jr., MD in 2010.

Dr. Sung joined the Stanford faculty in 2010 as Assistant Professor. He is also a staff physician at the Veteran’s Administration Palo Alto Health Care System.

In addition to his medical training, Dr. Sung worked extensively as a professional singer and actor for several years. He attended drama academy in New York City and performed in productions off-Broadway, in regional theaters, and in national and international tours. He has also performed with the Stanford University Symphonic Choir. He regularly lectures to voice and vocal pedagogy students in the Department of Music, in which he holds a courtesy appointment.

His clinical interests include the care of professional voice users; phonomicrosurgery; treatment of vocal fold paralysis with laryngeal framework surgery and injection techniques; diagnosis and Botox treatment of spasmodic dysphonia; office-based laser surgery; treatment of recurrent laryngeal papilloma; treatment of essential laryngeal tremor; and treatment of laryngeal cancer.

Clinical Focus

  • Otolaryngology
  • Laryngology
  • Voice Disorders
  • Hoarseness
  • Singers
  • Vocal Cord Paralysis
  • Spasmodic Dysphonia
  • Laryngeal Cancer
  • Laryngeal Laser Thearapy
  • Swallowing Disorders
  • Airway Disorders

Academic Appointments

  • Associate Professor - University Medical Line, Otolaryngology (Head and Neck Surgery)
  • Associate Professor - University Medical Line (By courtesy), Music

Administrative Appointments

  • Residency Program Director, Stanford University School of Medicine, Dept. of Otolaryngology - Head & Neck Surgery (2019 - Present)
  • Director of Otolaryngology Medical Student Clerkship, Stanford University School of Medicine, Dept. of Otolaryngology - Head & Neck Surgery (2011 - 2017)
  • Medical Student Admissions Reviewer, Stanford University School of Medicine (2012 - 2013)
  • Laryngology & Bronchoesophagology Education Committee, American Academy of Otolaryngology – Head and Neck Surgery (2011 - 2017)
  • Home Study Course Laryngology & Bronchoesophagology Working Group, American Academy of Otolaryngology – Head and Neck Surgery (2011 - 2017)
  • Course Director of Otolaryngology - Head & Neck Surgery Grand Rounds, Stanford University School of Medicine, Dept. of Otolaryngology (2011 - 2015)

Honors & Awards

  • Bay Area Top Doctors, San Francisco Magazine (2017-2024)
  • Honor Award, American Academy of Otolaryngology - Head & Neck Surgery (2023)
  • Patient-Centeredness Honoree, Stanford Health Care (2018-2019)
  • J. Arthur Campbell Award for Chemistry, Harvey Mudd College (1989)
  • Phi Lambda Upsilon, University of Pennsylvania (1989)
  • Outstanding Teaching Award, Department of Chemistry, University of Pennsylvania (1990)
  • Alpha Omega Alpha, SUNY Downstate Medical Center (2003)
  • Award for Outstanding Academic Achievement, Department of Otolaryngology, SUNY Downstate Medical Center (2004)
  • Magna Cum Laude, SUNY Downstate Medical Center (2004)
  • Third Prize, Metropolitan New York Resident Research Day Symposium (2007)
  • Travel Award, Triological Society (2007, 2009)
  • First Prize Proffered Paper Session, New York Head and Neck Society (2008)

Boards, Advisory Committees, Professional Organizations

  • Member, American Academy of Otolaryngology - Head & Neck Surgery (2005 - Present)
  • Diplomate, American Board of Otolaryngology (2010 - Present)
  • Member, Society of University Otolaryngologists (2012 - Present)
  • Member, American Broncho-Esophagological Association (ABEA) (2013 - Present)
  • Member, Otolaryngology Program Directors Organization (2019 - Present)

Professional Education

  • Internship: Icahn School of Medicine at Mount Sinai Department of Surgery-Division of General Surgery (2005) NY
  • Fellowship: Massachusetts Eye and Ear Infirmary Dept of Otolaryngology (2010) MA
  • Residency: Icahn School of Medicine at Mount Sinai Dept of Otolaryngology (2009) NY
  • Board Certification: American Board of Otolaryngology, Otolaryngology (2010)
  • Fellowship, Harvard Medical School - Massachusetts Eye & Ear Infirmary, Laryngology (2010)
  • Residency, Mt. Sinai School of Medicine, Otolaryngology (2009)
  • Internship, Mt. Sinai School of Medicine, General Surgery (2005)
  • MD, State University of New York - Downstate Medical Center, Medicine (2004)
  • MS, University of Pennsylvania, Organic Chemistry (1992)
  • BS, Harvey Mudd College, Chemistry (1989)

Current Research and Scholarly Interests

- Development of office-based laryngeal surgical methods and instrumentation.
- Clinical outcomes after treatment of glottic insufficiency.
- Clinical outcomes after treatment of benign vocal fold pathology.
- Medical student and resident training curriculum development.

2023-24 Courses

All Publications

  • Impact of Obesity on Timing of Tracheotomy: A Multi-institutional Retrospective Study. The Laryngoscope Yousef, A., Soliman, S. I., Solomon, I., Panuganti, B. A., Francis, D. O., Pang, J., Klebaner, D., Asturias, A., Alattar, A., Wood, S., Terry, M., Bryson, P. C., Tipton, C. B., Zhao, E. E., O'Rourke, A., Santa Maria, C., Grimm, D. R., Sung, C. K., Lao, W. P., Thompson, J. M., Crawley, B. K., Rosen, S., Berezovsky, A., Kupfer, R., Hennesy, T. B., Clary, M., Joseph, I. T., Sarhadi, K., Kuhn, M., Abdel-Aty, Y., Kennedy, M. M., Lott, D. G., Weissbrod, P. A. 2024


    To examine the impact of increased body mass index (BMI) on (1) tracheotomy timing and (2) short-term surgical complications requiring a return to the operating room and 30-day mortality utilizing data from the Multi-Institutional Study on Tracheotomy (MIST).A retrospective analysis of patients from the MIST database who underwent surgical or percutaneous tracheotomy between 2013 and 2016 at eight institutions was completed. Unadjusted and adjusted logistic regression analyses were used to assess the impact of obesity on tracheotomy timing and complications.Among the 3369 patients who underwent tracheotomy, 41.0% were obese and 21.6% were morbidly obese. BMI was associated with higher rates of prolonged intubation prior to tracheotomy accounting for comorbidities, indication for tracheotomy, institution, and type of tracheostomy (p = 0.001). Morbidly obese patients (BMI ≥35 kg/m2) experienced a longer duration of intubation compared with patients with a normal BMI (median days intubated [IQR 25%-75%]: 11.0 days [7-17 days] versus 9.0 days [5-14 days]; p < 0.001) but did not have statistically higher rates of return to the operating room within 30 days (p = 0.12) or mortality (p = 0.90) on multivariable analysis. This same finding of prolonged intubation was not seen in overweight, nonobese patients when compared with normal BMI patients (median days intubated [IQR 25%-75%]: 10.0 days [6-15 days] versus 10.0 days [6-15 days]; p = 0.36).BMI was associated with increased duration of intubation prior to tracheotomy. Although morbidly obese patients had a longer duration of intubation, there were no differences in return to the operating room or mortality within 30 days.III Laryngoscope, 2024.

    View details for DOI 10.1002/lary.31586

    View details for PubMedID 38895915

  • A Scoping Review of Artificial Intelligence Detection of Voice Pathology: Challenges and Opportunities. Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery Liu, G. S., Jovanovic, N., Sung, C. K., Doyle, P. C. 2024


    Survey the current literature on artificial intelligence (AI) applications for detecting and classifying vocal pathology using voice recordings, and identify challenges and opportunities for advancing the field forward.PubMed, EMBASE, CINAHL, and Scopus databases.A comprehensive literature search was performed following the Preferred Reporting Items for Systematic Reviews and Meta-analyses Extension for Scoping Reviews guidelines. Peer-reviewed journal articles in the English language were included if they used an AI approach to detect or classify pathological voices using voice recordings from patients diagnosed with vocal pathologies.Eighty-two studies were included in the review between the years 2000 and 2023, with an increase in publication rate from one study per year in 2012 to 10 per year in 2022. Seventy-two studies (88%) were aimed at detecting the presence of voice pathology, 24 (29%) at classifying the type of voice pathology present, and 4 (5%) at assessing pathological voice using the Grade, Roughness, Breathiness, Asthenia, and Strain scale. Thirty-six databases were used to collect and analyze speech samples. Fourteen articles (17%) did not provide information about their AI model validation methodology. Zero studies moved beyond the preclinical and offline AI model development stages. Zero studies specified following a reporting guideline for AI research.There is rising interest in the potential of AI technology to aid the detection and classification of voice pathology. Three challenges-and areas of opportunities-for advancing this research are heterogeneity of databases, lack of clinical validation studies, and inconsistent reporting.

    View details for DOI 10.1002/ohn.809

    View details for PubMedID 38738887

  • Parosteal Lipoma Overlying an Osteochondroma of the Hyoid Bone: A Case Report and Literature Review. The Laryngoscope Green, A., Wei, E. X., Chang-Graham, A., Holmes, B., Smith, A., Sung, C. K. 2023


    Parosteal lipomas and osteochondromas of the head and neck are uncommon benign tumors, constituting a small fraction of lipoma and bone tumor cases. We present a unique case of a 66-year-old male with a parosteal lipoma overlying an osteochondroma in the anterior midline neck, causing dysphagia. Surgical excision confirmed the diagnosis, and a literature review revealed similar cases predominantly adjacent to the mandible or calvaria. This case emphasizes the need to have parosteal lipoma and osteochondroma on the differential diagnosis for patients presenting with a firm mass of the central neck, especially with a history of trauma. Laryngoscope, 2023.

    View details for DOI 10.1002/lary.31192

    View details for PubMedID 37965970

  • Factors Associated With Otolaryngologists Performing Tracheotomy. JAMA otolaryngology-- head & neck surgery Soliman, S. I., Panuganti, B. A., Francis, D. O., Pang, J., Klebaner, D., Asturias, A., Alattar, A., Wood, S., Terry, M., Bryson, P. C., Tipton, C. B., Zhao, E. E., O'Rourke, A., Santa Maria, C., Grimm, D. R., Sung, C. K., Lao, W. P., Thompson, J. M., Crawley, B. K., Rosen, S., Berezovsky, A., Kupfer, R., Hennesy, T. B., Clary, M., Joseph, I. T., Sarhadi, K., Kuhn, M., Abdel-Aty, Y., Kennedy, M. M., Lott, D. G., Weissbrod, P. A. 2023


    Tracheotomies are frequently performed by nonotolaryngology services. The factors that determine which specialty performs the procedure are not defined in the literature but may be influenced by tracheotomy approach (open vs percutaneous) and other clinicodemographic factors.To evaluate demographic and clinical characteristics associated with tracheotomies performed by otolaryngologists compared with other specialists and to differentiate those factors from factors associated with use of open vs percutaneous tracheotomy.This multicenter, retrospective cohort study included patients aged 18 years or older who underwent a tracheotomy for cardiopulmonary failure at 1 of 8 US academic institutions between January 1, 2013, and December 31, 2016. Data were analyzed from September 2022 to July 2023.Tracheotomy.The primary outcome was factors associated with an otolaryngologist performing tracheotomy. The secondary outcome was factors associated with use of the open tracheotomy technique.A total of 2929 patients (mean [SD] age, 57.2 [17.2] years; 1751 [59.8%] male) who received a tracheotomy for cardiopulmonary failure (652 [22.3%] performed by otolaryngologists and 2277 [77.7%] by another service) were analyzed. Although 1664 of all tracheotomies (56.8%) were performed by an open approach, only 602 open tracheotomies (36.2%) were performed by otolaryngologists. Most tracheotomies performed by otolaryngologists (602 of 652 [92.3%]) used the open technique. Multivariable regression analysis revealed that self-reported Black race (odds ratio [OR], 1.89; 95% CI, 1.52-2.35), history of neck surgery (OR, 2.71; 95% CI, 2.06-3.57), antiplatelet and/or anticoagulation therapy (OR, 1.74; 95% CI, 1.29-2.36), and morbid obesity (OR, 1.54; 95% CI, 1.24-1.92) were associated with greater odds of an otolaryngologist performing tracheotomy. In contrast, history of neck surgery (OR, 1.36; 95% CI, 0.96-1.92), antiplatelet and/or anticoagulation therapy (OR, 0.80; 95% CI, 0.56-1.14), and morbid obesity (OR, 0.94; 95% CI, 0.74-1.19) were not associated with undergoing open tracheotomy when performed by any service, and Black race (OR, 0.56; 95% CI, 0.44-0.71) was associated with lesser odds of an open approach being used. Age-adjusted Charlson Comorbidity Index score greater than 4 was associated with greater odds of both an otolaryngologist performing tracheotomy (OR, 1.26; 95% CI, 1.03-1.53) and use of the open tracheotomy technique (OR, 1.48, 95% CI, 1.21-1.82).In this study, otolaryngologists were significantly more likely than other specialists to perform a tracheotomy for patients with history of neck surgery, morbid obesity, and ongoing anticoagulation therapy. These findings suggest that patients undergoing tracheotomy performed by an otolaryngologist are more likely to present with complex and challenging clinical characteristics.

    View details for DOI 10.1001/jamaoto.2023.2698

    View details for PubMedID 37796485

  • End-to-end deep learning classification of vocal pathology using stacked vowels. Laryngoscope investigative otolaryngology Liu, G. S., Hodges, J. M., Yu, J., Sung, C. K., Erickson-DiRenzo, E., Doyle, P. C. 2023; 8 (5): 1312-1318


    Advances in artificial intelligence (AI) technology have increased the feasibility of classifying voice disorders using voice recordings as a screening tool. This work develops upon previous models that take in single vowel recordings by analyzing multiple vowel recordings simultaneously to enhance prediction of vocal pathology.Voice samples from the Saarbruecken Voice Database, including three sustained vowels (/a/, /i/, /u/) from 687 healthy human participants and 334 dysphonic patients, were used to train 1-dimensional convolutional neural network models for multiclass classification of healthy, hyperfunctional dysphonia, and laryngitis voice recordings. Three models were trained: (1) a baseline model that analyzed individual vowels in isolation, (2) a stacked vowel model that analyzed three vowels (/a/, /i/, /u/) in the neutral pitch simultaneously, and (3) a stacked pitch model that analyzed the /a/ vowel in three pitches (low, neutral, and high) simultaneously.For multiclass classification of healthy, hyperfunctional dysphonia, and laryngitis voice recordings, the stacked vowel model demonstrated higher performance compared with the baseline and stacked pitch models (F1 score 0.81 vs. 0.77 and 0.78, respectively). Specifically, the stacked vowel model achieved higher performance for class-specific classification of hyperfunctional dysphonia voice samples compared with the baseline and stacked pitch models (F1 score 0.56 vs. 0.49 and 0.50, respectively).This study demonstrates the feasibility and potential of analyzing multiple sustained vowel recordings simultaneously to improve AI-driven screening and classification of vocal pathology. The stacked vowel model architecture in particular offers promise to enhance such an approach.AI analysis of multiple vowel recordings can improve classification of voice pathologies compared with models using a single sustained vowel and offer a strategy to enhance AI-driven screening of voice disorders.3.

    View details for DOI 10.1002/lio2.1144

    View details for PubMedID 37899847

    View details for PubMedCentralID PMC10601590

  • Tracheal stenosis and airway complications in the Coronavirus Disease-19 era. Annals of thoracic surgery short reports Krishnan, A., Guenthart, B. A., Choi, A., Trope, W., Berry, G. J., Pinezich, M. R., Vunjak-Novakovic, G., Shaller, B., Sung, C. K., Liou, D. Z., Damrose, E. J., Lui, N. S. 2023


    Severe Coronavirus Disease 2019 (COVID-19) infection is associated with prolonged intubation and its complications. Tracheal stenosis is one such complication that may require specialized surgical management. We aimed to describe the surgical management of post-COVID-19 tracheal stenosis.This case series describes consecutive patients with tracheal stenosis from intubation for severe COVID-19 infection at our single, tertiary academic medical center between January 1st, 2021, and December 31st, 2021. Patients were included if they underwent surgical management with tracheal resection and reconstruction, or bronchoscopic intervention. Operative through six-month, symptom-free survival and histopathological analysis of resected trachea were reviewed.Eight patients are included in this case series. All patients are female, and most (87.5%) are obese. Five patients (62.5%) underwent tracheal resection and reconstruction (TRR), while three patients (38.5%) underwent non-resection-based management. Among patients who underwent TRR, six-month symptom free survival is 80%; one patient (20%) required tracheostomy after TRR due to recurrent symptoms. Two of the three (66.7%) of patients who underwent non-resection-based management experienced durable relief from symptoms of tracheal stenosis with tracheal balloon dilation, and the remaining patient required laser excision of tracheal tissue prior to experiencing symptomatic relief.The incidence of tracheal stenosis may increase as patients recover from severe COVID-19 infection requiring intubation. Management of tracheal stenosis with TRR is safe and effective, with comparable rates of success to TRR for non-COVID-19 tracheal stenosis. Non-resection-based management is an option to manage tracheal stenosis in patients with less severe stenosis or in poor surgical candidates.

    View details for DOI 10.1016/j.atssr.2023.05.013

    View details for PubMedID 37360840

    View details for PubMedCentralID PMC10246306

  • Safety and Utility of Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE) for Laser Laryngeal Surgery. Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery Khan, N. C., Vukkadala, N., Saxena, A., Damrose, E. J., Nekhendzy, V., Sung, C. K. 2023


    OBJECTIVE: Transnasal humidified rapid-insufflation ventilatory exchange (THRIVE) is gaining acceptance as a safe method for apneic ventilation and oxygenation during laryngeal procedures, but remains controversial during laser laryngeal surgery (LLS) due to the theoretical risk of airway fire. This study describes our experience with THRIVE during LLS.STUDY DESIGN: Retrospective cohort study.SETTING: Stanford University Hospital, October 15, 2015 to June 1, 2021.METHODS: Retrospective chart review of patients ≥18 years who underwent LLS involving the CO2 or KTP laser with THRIVE as the primary mode of oxygenation.RESULTS: A total of172 cases were identified. 20.9% were obese (BMI≥30). Most common operative indication was subglottic stenosis. The CO2 laser was used in 79.1% of cases. Median lowest intraoperative SpO2 was 96%. 44.7% cases were solely under THRIVE while 16.3% required a single intubation and 19.2% required multiple intubations. Mean apnea time for THRIVE only cases was 32.1minutes and in cases requiring at least one intubation 24.0minutes (p<.001). Mean apnea time was significantly lower for patients who were obese (p<.001) or had a diagnosis of hypertension (p=.016). Obese patients and patients with hypertension were 2.03 and 1.43 times more likely to require intraoperative intubation, respectively. There were no intraoperative complications or fires since the institution of our LLS safety protocol.CONCLUSION: By eliminating the fuel component of the fire triangle, THRIVE can be safely used for continuous delivery of high FiO2 during LLS, provided adherence to institutional THRIVE-LLS protocols.

    View details for DOI 10.1002/ohn.324

    View details for PubMedID 37021493

  • Diagnosis and Management of Vocal Complications after Chondrolaryngoplasty. The Laryngoscope Nuyen, B., Qian, Z. J., Rakkar, M., Thomas, J. P., Erickson-DiRenzo, E., Sung, C. K. 2022


    OBJECTIVE: Transfeminine patients (transwomen/feminine nonbinary folks assigned male at birth) can undergo chondrolaryngoplasty ("tracheal shave") to feminize their neck appearance. While isolated cases of vocal complications have been reported following the procedure, aggregated outcomes have not been quantitatively studied. We present acoustic and stroboscopic data to describe a patient cohort with vocal complications after chondrolaryngoplasty and discuss reparative surgical technique.METHODS: Subjective and objective data, including videostroboscopy, were collected from patients with voice complaints after chondrolaryngoplasty. Dislocated anterior commissures were reconstructed with feminization laryngoplasty. Postoperative voice data were recorded and statistically compared to preoperative data using paired t-tests.RESULTS: On consecutive chart review, of the 94 transfeminine women with prior outside history of chondrolaryngoplasty, 27 (29%) reported chronic postoperative hoarseness, deepened pitch, or loss of upper register. On endoscopy, short, lax vocal folds with persistent anterior glottic gap and phase asymmetry were commonly noted; anterior commissure dislocation was confirmed in-office by using needle localization through absent thyroid cartilage. After open resuspension of the anterior commissure with feminization laryngoplasty, post-repair modal-speaking, minimum, and maximum fundamental frequencies (F0) increased on average by 7, 8, and 5 semitones, respectively (p<0.01), when compared to pre-repair values. On average, perioperative maximum phonation time did not change significantly (p=0.15). Average self-assessment of vocal femininity increased by 48% (p<0.01).CONCLUSION: Anterior commissure dislocation should be suspected with signs of vocal impairment after chondrolaryngoplasty. Following proper diagnosis, resuspension of the anterior commissure via feminization laryngoplasty approach can be an effective reparative technique.LEVEL OF EVIDENCE: This work represents a 2011 OCEBM Level 4 evidence as a case series Laryngoscope, 2022.

    View details for DOI 10.1002/lary.30518

    View details for PubMedID 36576093

  • Social Perception of External Laryngeal Anatomy Related to Gender Expression in a Web-based Survey. The Laryngoscope Kiessling, P., Balakrishnan, K., Fauer, A., Sanan, A., McDonald, D., Thomas, J., Erickson-Direnzo, E., Sung, C. K., Nuyen, B. 2022


    To quantify the effect of laryngeal prominence size on socially perceived attributes relating to gender expression. Chondrolaryngoplasty ("tracheal shave") is a common procedure performed for transgender women to feminize neck appearance. The extent of thyroid cartilage resection needed to convey socially-perceived feminine gender expression without destabilizing the voice is incompletely understood.Cross-sectional evaluation of a randomized allocation of images of varying laryngeal prominence to a non-repeated, random sample from November 2021 to December 2021. Photos of laryngeal prominence were isolated against a constant neck baseline with lateral, oblique, and frontal views. The images were embedded into a web-based survey with visual analog scales to capture perceived scaled gender expression (masculinity, femininity) and social traits (e.g., attractiveness, friendliness, leadership). We performed bivariate and multivariate analyses relating the laryngeal prominence to perceived gender expression and social traits.The analytic sample included 1,026 respondents. Laryngeal grades similar to the demonstrated "grade M" in this study and smaller demonstrated similar perceptions of increased femininity and decreased masculinity. Grades larger than M demonstrate significantly increased perceived masculinity and significantly decreased perceived femininity. The lateral and oblique views of the neck appear to be the most gender-informative.This crowd-sourced analysis of external laryngeal anatomy by a large population of observers provides clear, reproducible insights into social perceptions of gender identity and specifically femininity. These data will meaningfully inform patient counseling and surgical planning for gender-affirming interventions by establishing normative data representing the general public's perceptions.N/A Laryngoscope, 2022.

    View details for DOI 10.1002/lary.30498

    View details for PubMedID 36453533

  • Clinicodemographic Predictors of Tracheotomy Tube Size and Decannulation: A Multiinstitutional Retrospective Cohort Study on Tracheotomy. Annals of surgery Panuganti, B. A., Pang, J., Francis, D. O., Klebaner, D., Asturias, A., Alattar, A., Wood, S., Terry, M., Bryson, P. C., Tipton, C. B., Zhao, E. E., O'Rourke, A., Maria, C. S., Grimm, D. R., Sung, C. K., Lao, W. P., Thompson, J. M., Crawley, B. K., Rosen, S., Berezovsky, A., Kupfer, R., Hennesy, T. B., Clary, M., Joseph, I. T., Sarhadi, K., Kuhn, M., Abdel-Aty, Y., Kennedy, M. M., Lott, D. G., Weissbrod, P. A. 1800


    OBJECTIVE: We aimed to discern clinico-demographic predictors of large (≥8) tracheostomy tube size placement, and, secondarily, to assess the effect of large tracheostomy tube size and other parameters on odds of decannulation before hospital discharge.SUMMARY OF BACKGROUND DATA: Factors determining choice of tracheostomy tube size are not well-characterized in the current literature, despite evidence linking large tracheostomy tube size with posttracheotomy tracheal stenosis. The effect of tracheostomy tube size on timing of decannulation is also unknown, an important consideration given reported associations between endotracheal tube size and probability of failed extubation.METHODS: We collected information pertaining to patients who underwent tracheotomy at 1 of 10 U.S. health care institutions between 2010 and 2019. Tracheostomy tube size was dichotomized (≥8 and <8). Multivariable logistic regression models were fit to identify predictors of (1) large tracheostomy tube size, and (2) decannulation before hospital discharge.RESULTS: The study included 5307 patients, including 2797 (52.7%) in the large tracheostomy cohort. Patient height (OR = 1.060 per inch; 95% CI 1.041-1.070) and obesity (1.37; 95% CI 1.189-1.579) were associated with greater odds of large tracheostomy tube; otolaryngology performing the tracheotomy was associated with significantly lower odds of large tracheostomy tube (OR = 0.155; 95% CI 0.131-0.184). Large tracheostomy tube size (OR = 1.036; 95% CI 0.885-1.213) did not affect odds of decannulation.CONCLUSIONS: Obesity was linked with increased likelihood of large tracheostomy tube size, independent of patient height. Probability of decannulation before hospital discharge is influenced by multiple patient-centric factors, but not by size of tracheostomy tube.

    View details for DOI 10.1097/SLA.0000000000005356

    View details for PubMedID 35001037

  • Feminization Laryngoplasty: 17-Year Review on Long-Term Outcomes, Safety, and Technique. Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery Nuyen, B. A., Qian, Z. J., Campbell, R. D., Erickson-DiRenzo, E., Thomas, J., Sung, C. K. 2021: 1945998211036870


    OBJECTIVES: Transfeminine patients can experience significant gender dysphoria in vocal communication. Feminization laryngoplasty (FL) is a gender-affirming surgery developed to elevate speaking vocal range, as well as alter vocal resonance and laryngeal cosmesis. The purpose here was to appraise FL's long-term voice outcomes across a 17-year review period.STUDY DESIGN: Level III, retrospective study and description of technique.SETTING: A single-institution transfeminine voice clinic.METHODS: Voice data (speaking fundamental frequency [F0], lowest F0, highest F0, F0 range in both Hertz and semitones, and maximum phonation time [MPT]) were collected and assessed. Self-assessment of voice femininity and complications were documented.RESULTS: The 162 patients, all transfeminine women, had a mean age of 40 years with 36-month mean follow-up. There were significant increases in mean speaking F0 (Delta = 50 ± 30 Hz, Delta = 6 ± 3 semitones; P < .001) and mean change in lowest F0 (Delta = 58 ± 31 Hz, Delta = 8 ± 4 semitones; P < .001). There was no significant difference in mean change in highest F0 or MPT. There was significant improvement (Delta = 60% ± 39%; P < .001) in perceptual self-assessment of vocal femininity. There was a 1.2% rate of major postoperative complications requiring inpatient admission or operative intervention. There were no differences in vocal outcomes between those patients who had less than 1-year follow-up and those who had 5-year follow-up.CONCLUSION: FL in this cohort was a safe and effective technique for increasing mean speaking F0, mean lowest F0, and voice gender perception over a prolonged follow-up period. These findings add to the possible treatments aimed at addressing the morbid dysphoria related to voice and communication for our transfeminine patients.

    View details for DOI 10.1177/01945998211036870

    View details for PubMedID 34399638

  • Mainstream Cigarette Smoke Impacts the Mouse Vocal Fold Epithelium and Mucus Barrier. The Laryngoscope Erickson-DiRenzo, E., Easwaran, M., Martinez, J. D., Dewan, K., Sung, C. K. 2021


    OBJECTIVES/HYPOTHESIS: Cigarette smoke (CS) is a primary risk factor for the development of numerous benign and malignant laryngeal diseases. The epithelium and mucus lining the vocal folds (VF) are the first barriers against CS. The primary objective of this study was to investigate epithelial and mucus barrier changes in the mouse laryngeal mucosa upon exposure to subacute CS. The secondary objective was to compare mucus barrier changes in mice and human smokers and nonsmokers. Study Design Animal model.METHODS: Mice were exposed to CS for 4weeks for 4hours (N = 12, high dose [HD]) or 1hour (N = 12, low dose [LD]) per day. Air-exposed mice were used as a control group (N = 10). Larynges were harvested and VF epithelial barrier integrity was evaluated including cellular proliferation and expression of cell junctions. We also investigated mucus production by examining mucus cell area and mucin expression in mice and human smokers and nonsmokers.RESULTS: HD CS increased VF epithelial cellular proliferation but did not alter the expression of cell junctions. HD CS also induced hypertrophy of the mucus-producing submucosal glands. However, only LD CS increased MUC5AC gene expression. MUC5AC staining appeared elevated in laryngeal specimens from smokers, but this was not significant as compared to nonsmokers.CONCLUSIONS: These findings help us identify potential adaptive mechanisms to CS exposure as well as set the foundation for further study of key aspects of epithelial and mucus barrier integrity that may be implicated in laryngeal disease development following prolonged smoking.LEVEL OF EVIDENCE: NA Laryngoscope, 2021.

    View details for DOI 10.1002/lary.29572

    View details for PubMedID 33864646

  • Operative and Conservative Management of Laryngeal Contact Granuloma: A Network Analysis and Systematic Review JOURNAL OF VOICE Tsai, S., Ma, Y., Shih, L., Tsou, Y., Sung, C. 2021; 35 (2): 300–306
  • Otolaryngology Residency Interviews in a Socially Distanced World: Strategies to Recruit and Assess Applicants. Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery Chou, D. W., Pletcher, S. D., Bruss, D., Sung, C. K., Diaz, R. C., Liang, J., Durr, M. L. 2020: 194599820957961


    Due to concerns surrounding travel during the COVID-19 pandemic, the 2020-2021 otolaryngology residency application cycle will be conducted virtually for the first time. Residency programs should consider the logistics of video interviews, drawing on experiences of other programs that have successfully performed virtual interviews in the past. The lack of in-person interviews will create challenges in assessing applicants, and we recommend that programs develop structured and targeted questions and even consider having candidates answer standardized questions prior to the virtual interview day. From an applicant perspective, gauging the intangibles of individual residency programs, such as resident camaraderie, program culture, and program location, will be difficult. To address this, programs should consider hosting informal virtual gatherings, create videos that highlight the resident experience, and ensure that program websites are up-to-date. Ultimately, adaptability, resilience, and innovation will allow residency programs to achieve a successful 2021 otolaryngology match.

    View details for DOI 10.1177/0194599820957961

    View details for PubMedID 32870721

  • The Clinical Course of Idiopathic Bilateral Vocal Fold Motion Impairment in Adults: Case Series and Review of the Literature JOURNAL OF VOICE Abu Ghanem, S., Junlapan, A., Tsai, S., Shih, L., Sung, C., Damrose, E. J. 2020; 34 (3): 465–70
  • A Preliminary Study of Vocal Health Among Collegiate A Cappella Singers JOURNAL OF VOICE Baird, B. J., Mokhtari, T. E., Sung, C., Erickson-DiRenzo, E. 2020; 34 (3)
  • Vocal Hygiene in Collegiate Singers-Does Formal Training Relate to Practices? Journal of voice : official journal of the Voice Foundation Santa Maria, C., Sung, C., Baird, B. J., Erickson-DiRenzo, E. 2020


    BACKGROUND: Vocal hygiene is vitally important for protecting vocal quality and promoting vocal longevity. It includes adequate hydration, avoidance of environmental irritants, and refraining from phonotraumatic behaviors such as screaming, excessive talking, and throat clearing. Formal singing training in addition to enhancing singing techniques, is also assumed to promote good vocal hygiene. Consequently, we investigated whether collegiate singers with formal training are more likely to practice good vocal hygiene habits than untrained collegiate singers.METHODS: We completed a prospective cohort study, where collegiate singers at Stanford University were voluntarily enrolled in an annual vocal health clinic. Full laryngeal exams were performed and demographic information, formal vocal training status, and information on vocal hygiene habits were obtained through questionnaires. The results were then analyzed by grouping singers as "untrained" if less than 1 year of formal training, and "trained" if greater than a year.RESULTS: A total of 82 singers were included for analysis, with 49 (59.8%) having greater than one year of formal training. Trained singers were more likely to employ a primary musical singing style of classical or operatic singing compared to untrained singers who were more likely to utilize "R&B" (P < 0.001). No significant differences were found between groups for hydration practices (P=0.20), caffeine consumption (P=0.73), warm up practices (P=0.08), and phonotraumatic behaviors. Alcohol consumption, smoking tobacco, marijuana, e-cigarette usage was similar between groups. Overall, 11% of our sample reported intermittent less than daily marijuana use, with one singer reporting daily consumption. None of the singers in this sample used e-cigarettes. These rates are noticeably lower than the agematched United States population. Perceptions of cigarettes, marijuana, electronic cigarettes, alcohol, and caffeine were also the same between groups, with the vast majority of singers perceiving these agents as harmful to the voice (64%-100% depending on the agent). No laryngeal pathology was identified during laryngeal examination of any singers.CONCLUSIONS: Vocal hygiene habits are similar between trained and untrained collegiate singers. This likely relates to a desire for vocal longevity irrespective of prior training. This may dispel the long-held assumption that formal training was necessary to develop good vocal habits. We do however, present a very homogenous, highly educated sample of collegiate singers from Stanford University, having significantly less at-risk behavior than their aged-matched counterparts in the general US population. A lack of laryngeal pathology despite extensive vocal demands may also be reflective of good vocal hygiene habits.

    View details for DOI 10.1016/j.jvoice.2020.03.014

    View details for PubMedID 32362576

  • Intraoperative Evaluation of Essential Vocal Tremor in Deep Brain Stimulation Surgery. American journal of speech-language pathology Erickson-DiRenzo, E., Sung, C. K., Ho, A. L., Halpern, C. H. 2020: 1–13


    Purpose Essential vocal tremor (EVT) is a prevalent and difficult-to-manage voice disorder. There is evidence that deep brain stimulation (DBS) of the ventral intermediate nucleus (Vim) of the thalamus may be beneficial for treating EVT. The objective of this preliminary investigation was to conduct intraoperative voice assessments during Vim-DBS implantation in order to evaluate immediate voice outcomes in medication-refractory essential tremor patients with co-occurring EVT. Method Seven adult subjects diagnosed with EVT undergoing Vim-DBS surgery participated in this investigation. Voice samples of sustained vowels were collected by a speech-language pathologist preoperatively and intraoperatively, immediately following Vim-DBS electrode placement. Voice evaluation included objective acoustic assessment of the rate and extent of EVT fundamental frequency and intensity modulation and subjective perceptual ratings of EVT severity. Results The rate of intensity modulation, extent of fundamental frequency modulation, and perceptual rating of EVT severity were significantly reduced intraoperatively as compared to preoperatively. Moderate, positive correlations were appreciated between a subset of acoustic measures and perceptual severity ratings. Conclusions The results of this study demonstrate a speech-language pathologist can conduct intra-operative evaluation of EVT during DBS surgery. Using a noninvasive, simple acoustic recording method, we were able to supplement perceptual subjective observation with objective assessment and demonstrate immediate, intraoperative improvements in EVT. The findings of this analysis inform the added value of intraoperative voice evaluation in Vim-DBS patients and contribute to the growing body of literature seeking to evaluate the efficacy of DBS as a treatment for EVT.

    View details for DOI 10.1044/2019_AJSLP-19-00079

    View details for PubMedID 32073285

  • Multiparametric laryngeal assessment of the effect of thalamic deep brain stimulation on essential vocal tremor. Parkinsonism & related disorders Erickson-DiRenzo, E. n., Kuijper, F. M., Barbosa, D. A., Lim, E. A., Lin, P. T., Lising, M. A., Huang, Y. n., Sung, C. K., Halpern, C. H. 2020; 81: 106–12


    EVT is a refractory voice disorder that significantly affects quality of life. This work aims to conduct a multiparametric assessment of the effect of deep brain stimulation (DBS) of the thalamic ventral intermediate nucleus (VIM) on essential vocal tremor (EVT) and investigate the relation between DBS lead location and EVT outcomes.Nine participants underwent DBS for essential tremor and were diagnosed with co-occurring EVT in this prospective cohort study. Objective measurements including acoustic evaluation of vocal fundamental frequency (F0) and intensity modulation and subjective measurements including physiologic evaluation of the oscillatory movement of the laryngeal muscles and vocal tract and perceptual ratings of tremor severity were collected PRE and POST DBS. Finally, we investigated the relation between DBS lead location and EVT outcomes.Acoustic modulations of F0 and intensity were significantly improved POST DBS. Physiologic assessment showed a POST DBS reduction of oscillatory movement in the laryngeal muscles and vocal tract, but not significantly. Listener and participant perception, of EVT severity was also significantly reduced. Finally, our results indicate better EVT control with increased distance to midline of left VIM thalamic stimulation.By employing a battery of objective and subjective measures, our study supports the benefit of DBS for the treatment of EVT and specifies the acoustic and physiologic mechanisms that mediate its positive effect. We further provide preliminary results on the relation between lead location and EVT outcomes, laying the foundation for future studies to clarify the optimal DBS target for the treatment of EVT.

    View details for DOI 10.1016/j.parkreldis.2020.10.026

    View details for PubMedID 33120071

  • Coronavirus Disease 2019: Challenges Associated with the Treatment of Head and Neck Oncology and Laryngology Patients in the Coronavirus Disease 2019 Era. Otolaryngologic clinics of North America Baird, B. J., Sung, C. K. 2020


    This review explores the changes to practice associated with COVID-19 for providers treating patients with head and neck cancer and laryngeal pathology. The aim of the review is to highlight some of the challenges and considerations associated with treating this patient population during the pandemic. Additionally, it seeks to discuss some of the areas of concern related to ramping up clinical volume.

    View details for DOI 10.1016/j.otc.2020.08.004

    View details for PubMedID 33039099

  • Early Injection Laryngoplasty After Surgery: 30 Cases and Proposed Aspiration Assessment Protocol JOURNAL OF VOICE Abu-Ghanem, S., Rudy, S., Deane, S., Tsai, S., Shih, L., Damrose, E. J., Sung, C. 2020; 34 (1): 121–26
  • Autologous fibroblasts for vocal scars and age-related atrophy: A randomized clinical trial. The Laryngoscope Ma, Y., Long, J., Amin, M. R., Branski, R. C., Damrose, E. J., Sung, C., Achlatis, S., Kearney, A., Chhetri, D. K. 2019


    OBJECTIVES/HYPOTHESIS: To assess the safety and efficacy of autologous cultured fibroblasts (ACFs) to treat dysphonia related to vocal fold scar and age-related vocal atrophy (ARVA).STUDY DESIGN: Randomized, double-blinded, placebo-controlled, multi-institutional, phase II trial.METHODS: ACFs were expanded from punch biopsies of the postauricular skin in each subject; randomization was 2:1 (treatment vs. placebo). Three injections of 1-2*107 cells or placebo saline was performed at 4-week intervals for each vocal fold. Follow-up was performed at 4, 8, and 12 months. The primary outcome was improved mucosal waves. Secondary outcomes included Voice Handicap Index (VHI)-30, patient reported voice quality outcomes, and perceptual analysis of voice.RESULTS: Fifteen subjects received ACF and six received saline injections. At 4, 8, and 12 months after ACF treatments, a significant improvement in mucosal wave grade relative to baseline was observed in both vocal scar and ARVA groups. Relative to control group, mucosal waves were significantly improved in the ARVA group at 4 and 8 months. Perceptual analysis significantly improved in the vocal scar group 12 months after ACF treatments compared to controls. Vocal scar group reported significantly improved vocal quality from baseline. VHI and expert rater voice grade improved in both groups, but did not achieve significance. No adverse events related to fibroblast injections were observed.CONCLUSIONS: In this cohort, injection of ACFs into the vocal fold lamina propria (LP) was safe and significantly improved mucosal waves in patients with vocal scar and ARVA. ACF may hold promise to reconstruct the LP.LEVEL OF EVIDENCE: 1 Laryngoscope, 2019.

    View details for DOI 10.1002/lary.28453

    View details for PubMedID 31804729

  • Operative and Conservative Management of Laryngeal Contact Granuloma: A Network Analysis and Systematic Review. Journal of voice : official journal of the Voice Foundation Tsai, S. W., Ma, Y. F., Shih, L. C., Tsou, Y. A., Sung, C. 2019


    OBJECTIVE: Laryngeal contact granuloma is a disease of benign hypertrophic granulation tissue at the medial side of vocal process. Numerous studies of conservative and surgical management have reported effectiveness, yet optimal treatment has not been standardized. We compared primary and secondary outcomes of conservative and surgical treatment using endoscopic grading, Voice Handicap Index-10 (VHI-10), maximum phonation time (MPT), and recurrence rate.METHODS: We performed literature searches of MEDLINE, PubMed, and EMBASE from November 1985 to October 2017, with randomized controlled trials and case control studies of at least three months follow-up as the inclusion criteria. Outcomes included laryngoscopic findings, MPT, and VHI-10. Data regarding study design, outcome analysis, follow-up time, and disease remission were systematically collected.RESULTS: A total of 1069 patients were abstracted from 19 papers. With conservative treatment, 98% of patients' laryngeal granuloma resolved within three months, and 84% for the surgical group. There was a decrease in VHI-10 of 2.69 (95% credible interval (CI) -9.52 to 3.82) and 6.48 (95% CI -15.00 to 1.94) for conservative and surgical management, respectively. MPT improvement was 1.27 s (95% CI: 2.03-5.84) for conservative treatment and 5.02 s (95% CI: 0.78-8.07) for surgical. For all 19 studies, absolute recurrence risk for control, conservative, and surgical measures were respectively 4%, 16%, and 29%.CONCLUSIONS: Most patients treated conservatively or surgically alone responded to treatment, but conservative management was favored. VHI-10 and MPT improvement in surgical patients were noted, but only the latter was statistically significant. In regard to recurrence, conservative management had better outcome than surgical. Taken together, the results suggest that minimally symptomatic granulomas have higher response rate and lower recurrence risk when treated conservatively, while larger, symptomatic granulomas may favor surgical excision followed by medical management to reduce risk of recurrence.

    View details for DOI 10.1016/j.jvoice.2019.08.019

    View details for PubMedID 31628044

  • Outcomes in modified transoral resection of diverticula for Zenker's diverticulum EUROPEAN ARCHIVES OF OTO-RHINO-LARYNGOLOGY Junlapan, A., Abu-Ghanem, S., Sung, C., Damrose, E. J. 2019; 276 (5): 1423–29
  • Treatment of early-stage laryngeal cancer: A comparison of treatment options ORAL ONCOLOGY Baird, B., Sung, C., Beadle, B. M., Divi, V. 2018; 87: 8–16
  • Improvement in the Reflux Symptom Index Following Surgery for Cricopharyngeal Dysfunction JOURNAL OF VOICE Jiang, N., Sung, C. K., Damrose, E. J. 2017; 31 (1): 86-89


    Gastroesophageal reflux may contribute to the development of cricopharyngeal dysfunction and Zenker's diverticulum. Common dictum suggests that if upper esophageal sphincter tone is reduced through cricopharyngeal myotomy, symptoms of laryngopharyngeal reflux may worsen. We hypothesized that patients who undergo myotomy should show decreased dysphagia symptoms with concurrent worsening of reflux symptomatology and that these changes would be greater in those patients undergoing complete versus partial myotomy.A retrospective chart review was performed for patients who underwent endoscopic or open cricopharyngeal myotomy, with or without Zenker's diverticulectomy. Preoperative and postoperative reflux symptomatology was subjectively measured with the Reflux Symptom Index (RSI), and dysphagia symptomatology was measured with the Eating Assessment Tool 10 (EAT-10). Patients who underwent partial myotomy via endoscopic stapling of Zenker's diverticulum were compared with patients who underwent complete myotomy (either endoscopic laser-assisted or via an open transcervical approach). The patients were further subdivided into three groups for data analysis: endoscopic staple diverticulotomy, laser cricopharyngeal myotomy, and open approach.A total of 41 patient charts were reviewed. Of these 41 patients, 17 underwent endoscopic stapler-assisted diverticulotomy, 4 underwent endosopic laser-assisted cricopharyngeal myotomy, and 20 underwent open transcervical cricopharyngeal myotomy, with diverticulectomy as indicated. Mean pre- and postoperative RSIs were 21.8 and 8.9, respectively (P < 0.001). Mean pre- and postoperative EAT-10 scores were 19.1 and 5.0, respectively (P < 0.001).Patients' reflux symptoms significantly improved after cricopharyngeal myotomy, with significant improvement in dysphagia symptoms. Concern for worsening of reflux symptoms following surgery does not appear to be clinically common.

    View details for DOI 10.1016/j.jvoice.2016.02.006

    View details for PubMedID 27049450

  • Surgical Management of Supraglottic Stenosis Using Intubationless Optiflow. The Annals of otology, rhinology, and laryngology Tam, K. n., Jeffery, C. n., Sung, C. K. 2017; 126 (9): 669–72


    Airway management during endoscopic surgical treatment of supraglottic and pharyngeal stenosis is often challenging and can be accomplished by various means, including tracheostomy, jet ventilation, or direct laryngoscopy. We describe CO2 laser excision of supraglottic-pharyngeal stenosis using intubationless Optiflow high-flow nasal cannula (HFNC).A 55-year-old male presented with dyspnea and dysphagia secondary to severe supraglottic-pharyngeal stenosis in the setting of previous chemoradiation for a T0N2aM0 squamous cell carcinoma. Laryngoscopy revealed severe supraglottic-pharyngeal stenosis with tethering of the epiglottis to the lateral pharyngeal walls. Optiflow HFNC was used to deliver 70 L/min of oxygen. After anesthetic induction, CO2 laser microlaryngoscopy was utilized to release scar tissue along the lateral epiglottic border, opening up the supraglottic airway sufficiently for endotracheal intubation and further laser resection.Airway management with Optiflow HFNC allowed initial endoscopic surgical access, partial stenotic release, and intubation. From anesthetic induction to intubation, the patient remained apneic for 26 minutes. The patient's stenosis was successfully addressed, and 10-month follow-up demonstrated stable patency of the airway.Optiflow is an important new tool in the management of severe supraglottic stenosis. It provides sufficient oxygenation to perform extended apneic surgery and improves endoscopic surgical access in a limited airway.

    View details for PubMedID 28766977

  • Phonomicrosurgery simulation: A low-cost teaching model using easily accessible materials. Laryngoscope Zambricki, E. A., Bergeron, J. L., DiRenzo, E. E., Sung, C. K. 2016; 126 (11): 2528-2533


    To introduce the use of a new phonomicrosurgical trainer using easily accessible materials, and to establish the effectiveness of the model.The model uses a grape imbedded in gelatin, a microscope, and microlaryngeal instruments. The study was designed to test baseline differences in training levels, as well as improvement in performance after training with the simulation model.Thirty subjects enrolled in the Stanford University School of Medicine otolaryngology training program performed microlaryngeal surgery tasks on a grape. Tasks were designed to model both excision of a vocal fold lesion and vocal fold injection. Anonymized video recordings comparing presimulation and postsimulation training were collected and graded by an expert laryngologist. Both objective comparison of skills and subjective participant surveys were analyzed.Objectively, trainees in all groups made statistically significant improvements across all tested variables, including microscope positioning, creation of a linear incision, elevation of epithelial flaps, excision of a crescent of tissue, vocal fold injection, preservation of remaining tissue, and time to complete all tasks. Subjectively, 100% of participants felt that they had increased comfort with microlaryngeal instruments and decreased intimidation of microlaryngeal surgery after completing the simulation training. This appreciation of skills was most notable and statistically significant in the intern trainees.Microlaryngeal surgical simulation is a tool that can be used to train residents to prepare them for phonomicrosurgical procedures at all levels of training. Our low-cost model with accessible materials can be easily duplicated and used to introduce trainees to microlaryngeal surgery or improve skills of more senior trainees.1B. Laryngoscope, 2016.

    View details for DOI 10.1002/lary.25940

    View details for PubMedID 27107403

  • Consultation via telemedicine and access to operative care for patients with head and neck cancer in a Veterans Health Administration population HEAD AND NECK-JOURNAL FOR THE SCIENCES AND SPECIALTIES OF THE HEAD AND NECK Beswick, D. M., Vashi, A., Song, Y., Pham, R., Holsinger, F. C., Rayl, J. D., Walker, B., Chardos, J., Yuan, A., Benadam-Lenrow, E., Davis, D., Sung, C. K., Divi, V., Sirjani, D. B. 2016; 38 (6): 925-929


    The purpose of this study was to evaluate a telemedicine model that utilizes an audiovisual teleconference as a preoperative visit.Veterans Health Administration (VHA) patients with head and neck cancer at 2 remote locations were provided access to the Palo Alto Veterans Affairs (PAVA) Health Care System otolaryngology department via the telemedicine protocol: tissue diagnosis and imaging at the patient site; data review at PAVA; and a preoperative teleconference connecting the patient to PAVA. Operative care occurred at PAVA. Follow-up care was provided remotely via teleconference.Fifteen patients were evaluated. Eleven underwent surgery, 4 with high-grade neoplasms (carcinoma). Average time from referral to operation was 28 days (range, 17-36 days) and 72 (range, 31-108 days), respectively, for high-grade and low-grade groups. The average patient was spared 28 hours traveling time and $900/patient was saved on travel-related costs.A telemedicine model enables timely access to surgical care and permits considerable savings among select VHA patients with head and neck cancer. © 2016 Wiley Periodicals, Inc. Head Neck 38: 925-929, 2016.

    View details for DOI 10.1002/hed.24386

    View details for PubMedID 26899939

  • Tracheal Stenosis Because of Wegener Granulomatosis Misdiagnosed as Asthma. A & A case reports O'Hear, K. E., Ingrande, J., Brodsky, J. B., Morton, J. M., Sung, C. 2016; 6 (10): 311-312


    We describe a patient with Wegener granulomatosis whose complaint of wheezing was incorrectly attributed to asthma. Anesthesiologists must recognize that tracheal stenosis is extremely common in Wegener granulomatosis and can mimic other causes of wheezing.

    View details for DOI 10.1213/XAA.0000000000000307

    View details for PubMedID 27075424

  • Symptomatic Anterior Cervical Osteophyte Causing Dysphagia: Case Report, Imaging, and Review of the Literature. Cure¯us Chen, Y., Sung, K., Tharin, S. 2016; 8 (2)


    Anterior cervical osteophytes are found in 20-30% of elderly patients. Rarely, severe osteophytes can cause dysphagia, dysphonia, and dyspnea. Here, we illustrate a case of severe dysphagia caused by a large post-traumatic osteophyte with oropharyngeal swallow study showing a significant mass effect on the pharynx and resolution following osteophytectomy. We also review the literature regarding the etiology, diagnosis, and treatment of symptomatic anterior cervical osteophytes.

    View details for DOI 10.7759/cureus.473

    View details for PubMedID 27004150

    View details for PubMedCentralID PMC4779080

  • Deep brain stimulation for vocal tremor: a comprehensive, multidisciplinary methodology NEUROSURGICAL FOCUS Ho, A. L., Erickson-DiRenzo, E., Pendharkar, A. V., Sung, C., Halpern, C. H. 2015; 38 (6)


    Tremulous voice is a characteristic feature of a multitude of movement disorders, but when it occurs in individuals diagnosed with essential tremor, it is referred to as essential vocal tremor (EVT). For individuals with EVT, their tremulous voice is associated with significant social embarrassment and in severe cases may result in the discontinuation of employment and hobbies. Management of EVT is extremely difficult, and current behavioral and medical interventions for vocal tremor result in suboptimal outcomes. Deep brain stimulation (DBS) has been proposed as a potential therapeutic avenue for EVT, but few studies can be identified that have systematically examined improvements in EVT following DBS. The authors describe a case of awake bilateral DBS targeting the ventral intermediate nucleus for a patient suffering from severe voice and arm tremor. They also present their comprehensive, multidisciplinary methodology for definitive treatment of EVT via DBS. To the authors' knowledge, this is the first time comprehensive intraoperative voice evaluation has been used to guide microelectrode/stimulator placement, as well as the first time that standard pre- and post-DBS assessments have been conducted, demonstrating the efficacy of this tailored DBS approach.

    View details for DOI 10.3171/2015.3.FOCUS1537

    View details for Web of Science ID 000355539900006

    View details for PubMedID 26030706

  • Deep brain stimulation for vocal tremor: a comprehensive, multidisciplinary methodology. Neurosurgical focus Ho, A. L., Erickson-DiRenzo, E., Pendharkar, A. V., Sung, C., Halpern, C. H. 2015; 38 (6): E6-?


    Tremulous voice is a characteristic feature of a multitude of movement disorders, but when it occurs in individuals diagnosed with essential tremor, it is referred to as essential vocal tremor (EVT). For individuals with EVT, their tremulous voice is associated with significant social embarrassment and in severe cases may result in the discontinuation of employment and hobbies. Management of EVT is extremely difficult, and current behavioral and medical interventions for vocal tremor result in suboptimal outcomes. Deep brain stimulation (DBS) has been proposed as a potential therapeutic avenue for EVT, but few studies can be identified that have systematically examined improvements in EVT following DBS. The authors describe a case of awake bilateral DBS targeting the ventral intermediate nucleus for a patient suffering from severe voice and arm tremor. They also present their comprehensive, multidisciplinary methodology for definitive treatment of EVT via DBS. To the authors' knowledge, this is the first time comprehensive intraoperative voice evaluation has been used to guide microelectrode/stimulator placement, as well as the first time that standard pre- and post-DBS assessments have been conducted, demonstrating the efficacy of this tailored DBS approach.

    View details for DOI 10.3171/2015.3.FOCUS1537

    View details for PubMedID 26030706

  • Deep Brain Stimulation for Essential Vocal Tremor: A Technical Report. Cureus Ho, A. L., Choudhri, O., Sung, C. K., DiRenzo, E. E., Halpern, C. H. 2015; 7 (3)


    Essential vocal tremor (EVT) is the presence of a tremulous voice that is commonly associated with essential tremor. Patients with EVT often report a necessary increase in vocal effort that significantly worsens with stress and anxiety and can significantly impact quality of life despite optimal medical and behavioral treatment options. Deep brain stimulation (DBS) has been proposed as an effective therapy for vocal tremor, but very few studies exist in the literature that comprehensively evaluate the efficacy of DBS for specifically addressing EVT. We present a technical report on our multidisciplinary, comprehensive operative methodology for treatment of EVT with frameless, awake deep brain stimulation (DBS).

    View details for DOI 10.7759/cureus.256

    View details for PubMedID 26180680

  • Endoscopic suture retriever for endolaryngeal keel placement in treatment of anterior glottic webs. The Annals of otology, rhinology, and laryngology Beswick, D. M., Clark, A. K., Bergeron, J., Sung, C. K. 2015; 124 (3): 240-243


    Endoscopic placement of a laryngeal keel has traditionally required the use of a Lichtenberger endo-extralaryngeal needle passer, which is not universally available. We discuss a safe and technically simple alternate technique using an endoscopic suture retriever through a percutaneously placed angiocatheter that obviates the need for the Lichtenberger instrument.Case series.Two 14-gauge angiocatheters were passed through the anterior neck under telescopic visualization of the larynx. The suture retriever was inserted through the catheter and deployed within the larynx to withdraw a Prolene suture that was threaded through a Silastic keel. The keel was then tied in position over a sterile button on the anterior neck.This procedure was performed on 2 patients with excellent outcomes in both cases.Endoscopic keel placement is a widely used procedure for treating anterior glottic webs and requires suture passage from within the larynx to the anterior neck to secure the keel into position. This is the first report of an exo-endolaryngeal suture retriever for placement of a laryngeal keel. This technique provides a safe, reliable, and efficient alternative to endo-extralaryngeal needle puncture and uses materials that are available in many operating room settings.

    View details for DOI 10.1177/0003489414549577

    View details for PubMedID 25204710

  • Office-Based Laser Laryngeal Surgery Op Tech in Otolaryngol Sung CK 2012; 23 (2): 102-105
  • Management of Recurrent Laryngeal Nerve Paralysis Surgery of the Thyroid and Parathyroid Glands Sung CK, Franco RA Jr. 2011
  • Airway and respiratory complications: Tracheal Stenosis Spinal Cord Injury: Rehabilitation Medicine Quick Reference Altman KW, Sung CK 2010
  • Airway and respiratory interventions: Tracheostomies. Spinal Cord Injury: Rehabilitation Medicine Quick Reference Altman KW, Sung CK 2010


    The aim of this prospective study was to determine the technical feasibility, safety, and efficacy of transoral robotic surgery (TORS) for a variety of malignant head and neck lesions.From April 2007 to November 2007, 20 patients were enrolled in an institutional review board-approved prospective trial using the daVinci surgical robot. Inclusion criteria for the study consisted of adults with early head and neck cancer involving the oral cavity, oropharynx, hypopharynx, and larynx.Twenty patients were included in this study. In 2 cases, access to the tumor was inadequate and the procedure was terminated. In all 18 cases, negative resection margins were achieved. Intraoral reconstruction was performed in 8 patients. Fifteen of 18 patients underwent concomitant unilateral (n = 10) or bilateral (n = 5) selective neck dissections. None of the patients required tracheotomy and there were no intraoperative or postoperative complications. The average setup time was 54.6 minutes (range, 140-20 minutes), with a precipitous decrease in the setup time as the study progressed.TORS is a safe, feasible, and minimally invasive alternative to classic open surgery or endoscopic transoral laser surgery in patients with early cancer of the head and neck. With increasing experience, surgical setup as well as operative time will continue to decrease.

    View details for DOI 10.1002/hed.20972

    View details for Web of Science ID 000264011500001

    View details for PubMedID 18972413

  • Transoral robotic assisted free flap reconstruction OTOLARYNGOLOGY-HEAD AND NECK SURGERY Mukhija, V. K., Sung, C., Desai, S. C., Wanna, G., Genden, E. M. 2009; 140 (1): 124-125

    View details for DOI 10.1016/j.otohns.2008.09.024

    View details for Web of Science ID 000262458100025

    View details for PubMedID 19130975

  • Transoral Robotic Surgery Using a Carbon Dioxide Flexible Laser for Tumors of the Upper Aerodigestive Tract LARYNGOSCOPE Desai, S. C., Sung, C., Jang, D. W., Genden, E. M. 2008; 118 (12): 2187-2189


    To determine the safety, feasibility, and efficacy of coupling transoral robotic technology with the flexible carbon dioxide (CO2) laser for various tumors of the oropharynx and supraglottic larynx.Prospective, pilot trial.Eight patients were enrolled in an IRB-approved prospective trial for transoral robotic surgery with the aid of the flexible CO2 laser.Seven male patients with early carcinoma of the oropharynx or larynx successfully underwent tumor extirpation with the transoral robot and the flexible CO2 laser. We were unable to gain access to the supraglottic larynx in one female patient. The final pathology revealed seven patients with squamous cell carcinoma and one patient with adenoid cystic carcinoma. The flexible CO2 laser provided fine incisions with excellent hemostasis and minimal peripheral tissue injury. Additionally, the laser provided an excellent tool for raising pharyngeal flaps for reconstruction of the oropharynx.The flexible CO2 laser offers a unique advantage of precise incisions and may provide a valuable tool for both tumor extirpation and the creation of flaps for transoral robotic reconstruction.

    View details for DOI 10.1097/MLG.0b013e31818379e4

    View details for Web of Science ID 000263200900019

    View details for PubMedID 19029867

  • Transoral Robotic Surgery Using an Image Guidance System LARYNGOSCOPE Desai, S. C., Sung, C., Genden, E. M. 2008; 118 (11): 2003-2005


    To describe a novel technique using the image guidance system for transoral robotic surgery of the pharyngeal and parapharyngeal spaces.Case series presentation.Three cases of oropharyngeal and pharyngeal space lesions are reviewed for presentation, workup, and original management.Final pathology of a vascular malformation, an acinic cell adenocarcinoma, and a squamous cell carcinoma were located and minimally invasively removed by a transoral robotic approach with the aid of image guidance. No complications or recurrences were observed on an average of 7 month follow-up.Transoral robotic surgery using an image guidance system seems safe and effective in assisting dissection.

    View details for DOI 10.1097/MLG.0b013e3181818784

    View details for Web of Science ID 000260874700017

    View details for PubMedID 18849862

  • The administration of IL-12/GM-CSF and Ig-4-1BB ligand markedly decreases murine floor of mouth squamous cell cancer OTOLARYNGOLOGY-HEAD AND NECK SURGERY Adappa, N. D., Sung, C., Choi, B., Huang, T., Genden, E. M., Shin, E. J. 2008; 139 (3): 442-448


    To assess immune-based gene therapy in a murine floor of mouth (FOM) squamous cell carcinoma (SCC) model.In vitro and in vivo testing of immune therapy for SCC.Multiple SCC lines were infected by using advRSV-interleukin-12 (IL-12) and advCMV-interleukin-12/granulocyte macrophage colony-stimulating factor (IL-12/GM-CSF) and monitored for production of IL-12 and GM-CSF. Intratumoral injections of viral vectors were administered with systemic Ig-4-1BB ligand in an orthotopic murine FOM SCC model and followed for tumor size and survival.In vitro, all cell lines produced substantial levels of IL-12 and GM-CSF. In vivo, tumors treated with advCMV-IL-12/GM-CSF and Ig-4-1BBL showed a striking reduction in tumor volume (vs control P<0.0001) and improved median survival (38 days vs 19 days for control, P<0.0001).Combination immune-based therapies effectively improve survival in mice bearing FOM SCC over single-modality therapy.

    View details for DOI 10.1016/j.otohns.2008.05.001

    View details for Web of Science ID 000258858400020

    View details for PubMedID 18722228

  • Combined VSV Oncolytic Virus and Chemotherapy for Squamous Cell Carcinoma 110th Annual Meeting of the Triological-Society Sung, C., Choi, B., Wanna, G., Genden, E. M., Woo, S. L., Shin, E. J. WILEY-BLACKWELL. 2008: 237–42


    Vesicular stomatitis virus (VSV) is a negative-strand ribonucleic acid (RNA) virus that replicates specifically in tumor cells and has oncolytic effects in a variety of malignant tumors. We previously demonstrated recombinant VSV vectors incorporating viral fusion protein (rVSV-F) and interleukin 12 (rVSV-IL12) to have significant antitumor effects against squamous cell carcinoma (SCC) in a murine model. Here we evaluate the potential to combine a potent chemotherapeutic agent for SCC (cisplatin) with rVSV-F and rVSV-IL12 to improve efficacy.In vitro, three SCC cell lines were tested using rVSV-F and rVSV-IL12 with cisplatin, monitoring viral replication and cell survival. In an orthotopic floor of mouth murine SCC model, intratumoral injections of virus combined with systemic cisplatin were tested for tumor control and animal survival.In vitro, virus and cisplatin combination demonstrated rapid replication and enhanced tumor cell kill. Human keratinocytes were unaffected by virus and cisplatin. In vivo, combined rVSV-F with cisplatin reduced tumor burden and improved survival (P = .2 for both), while rVSV-IL12 monotherapy had better tumor control (P = .06) and survival (P = .024) than combination therapy.Addition of cisplatin did not affect the ability of either virus to replicate in or kill murine SCC cells in vitro. In vivo, combination therapy enhancedrVSV-F antitumor activity, but diminished rVSV-IL12 antitumor activity. Combination therapy may provide useful treatment for SCC with the development of more efficient viral vectors in combination with different chemotherapy agents or immunostimulatory agents.

    View details for DOI 10.1097/MLG.0b013e3181581977

    View details for Web of Science ID 000260661500008

    View details for PubMedID 18043494