Clinical Focus


  • Otolaryngology

Academic Appointments


  • Clinical Professor, Otolaryngology - Head & Neck Surgery Divisions

Professional Education


  • Residency: UCLA GME Office (1975) CA
  • Internship: Alameda County Medical Center UCSF East Bay Surgical Residency (1978) CA
  • Board Certification: Otolaryngology, American Board of Otolaryngology (1982)
  • Residency: Stanford University School of Medicine (1982) CA
  • Medical Education: University of Alabama School of Medicine (1977) AL

All Publications


  • The Role of the Revised Stanford Protocol in Today's Precision Medicine. Sleep medicine clinics Liu, S. Y., Awad, M., Riley, R., Capasso, R. 2019; 14 (1): 99–107

    Abstract

    Whereas the original Stanford protocol relied on a tiered approach to care to avoid unnecessary surgery, it did not address the issue of surgical relapse, a common concern among sleep medicine specialists. With 3 decades of experience since the original 2-tiered Powell-Riley protocol was introduced and the role of evolving skeletal techniques and upper airway stimulation, we are pleased to present our current protocol. This update includes emphasis on the facial skeletal development with impact on function including nasal breathing, and the incorporation of upper airway stimulation. The increased versatility of palatopharyngoplasty as an adjunctive procedure is also discussed.

    View details for PubMedID 30709539

  • Maxillomandibular Advancement: Contemporary Approach at Stanford. Atlas of the oral and maxillofacial surgery clinics of North America Liu, S. Y., Awad, M., Riley, R. W. 2019; 27 (1): 29–36

    Abstract

    Maxillomandibular advancement (MMA) for the treatment of obstructive sleep apnea (OSA) has remained a reliable and highly effective surgical intervention since its introduction in 1989. Modifications have been made to maximize skeletal movement and upper airway stability without compromising facial balance. Contemporary indications of recommending MMA prior to other soft tissue surgery are described. MMA poses unique challenges to surgeons. There are patient-related factors, including OSA, a chronic inflammatory condition with associated cardiovascular and metabolic comorbidity. Perioperative management is more complex than routine orthognathic patients. Key details are shared from a 3-decade experience at Stanford.

    View details for PubMedID 30717921

  • Corrective Nasal Surgery after Maxillomandibular Advancement for Obstructive Sleep Apnea: Experience from 379 Cases. Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery Liu, S. Y., Lee, P., Awad, M., Riley, R. W., Zaghi, S. 2017: 194599817695807-?

    Abstract

    Objective Efficacy of maxillomandibular advancement (MMA) in the treatment of obstructive sleep apnea (OSA) is associated with degree of maxillary advancement. Large maxillary advancement leads to profound changes of the nasolabial region. We present the incidence and indications of post-MMA corrective nasal surgery in a large cohort. Study Design Case series with chart review. Setting University medical center. Subjects and Methods A total of 379 subjects with OSA underwent MMA at Stanford Hospital (surgeons: S.Y.L., R.W.R.) from August 1992 to December 2015. Data were collected on age, sex, American Society of Anesthesiologists score, polysomnography parameters, and history of nasal surgery. Primary outcome parameters were the incidence and indications of post-MMA corrective nasal surgery. Results Of 379 subjects, the surgical success rate was 76.3% based on the change in respiratory disturbance index. Seventy-one subjects (18.7%) underwent corrective nasal surgery after MMA, whereas 48 underwent functional nasal surgery and 23 underwent both functional and aesthetic nasal surgery. Lower oxygen saturation nadir and higher baseline respiratory disturbance index were associated with increased likelihood of post-MMA corrective nasal surgery. Conclusion MMA surgical success is associated with degree of maxillary advancement, which is especially significant in patients with severe OSA. Patients must be counseled on its impact in nasal function and aesthetics. Our series, the largest to date to address this question, suggests that the incidence of post-MMA corrective nasal surgery is at least 18.7%. Prospectively, refinement in MMA techniques is needed to minimize postoperative compromise in nasal form and function.

    View details for DOI 10.1177/0194599817695807

    View details for PubMedID 28417661

  • Sleep surgery tool: A medical checklist to review prior to operating. Journal of cranio-maxillo-facial surgery : official publication of the European Association for Cranio-Maxillo-Facial Surgery Camacho, M., Riley, R. W., Capasso, R., O'Connor, P., Chang, E. T., Reckley, L. K., Guilleminault, C. 2017; 45 (3): 381-386

    Abstract

    The objective of this study was to systematically review the international literature for studies providing a preoperative checklist for medical disorders to be evaluated or treated before performing sleep surgery. If no checklist exists, then studies providing recommendations would be used to develop a checklist de novo.Systematic review combined with expert opinion.Four databases, including PubMed/Medline were searched through August 10, 2016.453 potentially relevant studies were screened, 32 were downloaded for full review. No study included a preoperative checklist. No study provided guidance for specific medical disorders to evaluate or screen for prior to sleep surgery. Therefore, we reviewed articles in adults that provided recommendations such as: (1) labs to review, (2) non-operative disorders to evaluate and treat, and (3) comorbidities to optimize prior to performing sleep surgery. These articles were utilized in conjunction with expert opinion to develop a preoperative checklist for surgical guidance.There are several items to review prior to performing sleep surgery on obstructive sleep apnea patients. This systematic review and expert opinion-based checklist provides over twenty items for reviewing prior to performing sleep surgery to reduce the chance of operating prematurely.

    View details for DOI 10.1016/j.jcms.2017.01.001

    View details for PubMedID 28169045

  • Continuing the Original Stanford Sleep Surgery Protocol From Upper Airway Reconstruction to Upper Airway Stimulation: Our First Successful Case. Journal of oral and maxillofacial surgery Liu, S. Y., Riley, R. W. 2017

    Abstract

    In 1993, a surgical protocol for dynamic upper airway reconstruction in patients with obstructive sleep apnea (OSA) was published, and it became commonly known as the Stanford phase 1 and 2 sleep surgery protocol. It served as a platform on which research and clinical studies have continued to perfect the surgical care of patients with OSA. However, relapse is inevitable in a chronic condition such as OSA, and a subset of previously cured surgical patients return with complaints of excessive daytime sleepiness. This report describes a patient who was successfully treated with phase 1 and 2 operations more than a decade previously. He returned at 65 years of age with relapse of moderate OSA, and after workup with polysomnography and drug-induced sleep endoscopy, he underwent upper airway stimulation of the hypoglossal nerve that resulted in cure of OSA. This case shows why upper airway stimulation is an appropriate option for patients with OSA and previously successful maxillomandibular advancement.

    View details for DOI 10.1016/j.joms.2017.02.008

    View details for PubMedID 28294946

  • An Accurate Method of Designing and Performing Individual-Specific Genioglossus Advancement OTOLARYNGOLOGY-HEAD AND NECK SURGERY Liu, S. Y., Huon, L., Zaghi, S., Riley, R., Torre, C. 2017; 156 (1): 194-197

    Abstract

    There is too much individual patient variation in mandibular anatomy for any single described genioglossus advancement technique to be used consistently. Virtual surgical planning allows surgeons to design genioglossus osteotomy that captures the structures of interest. Intraoperative osteotomy and positioning guides mitigate known risks of the procedure while maximizing the reproducibility and efficacy of the procedure. In this report, we demonstrate the protocol step by step as it had been used on 10 patients, and we highlight 3 clinical scenarios that exemplify its utility.

    View details for DOI 10.1177/0194599816670366

    View details for PubMedID 28045634

  • Efficacy of Maxillomandibular Advancement Examined with Drug-Induced Sleep Endoscopy and Computational Fluid Dynamics Airflow Modeling. Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery Liu, S. Y., Huon, L., Iwasaki, T., Yoon, A., Riley, R., Powell, N., Torre, C., Capasso, R. 2016; 154 (1): 189-195

    Abstract

    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.Retrospective cohort study.University medical center.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.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/m(2) 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).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.

    View details for DOI 10.1177/0194599815611603

    View details for PubMedID 26740522

  • Efficacy of Maxillomandibular Advancement Examined with Drug-Induced Sleep Endoscopy and Computational Fluid Dynamics Airflow Modeling OTOLARYNGOLOGY-HEAD AND NECK SURGERY Liu, S. Y., Huon, L., Iwasaki, T., Yoon, A., Riley, R., Powell, N., Torre, C., Capasso, R. 2016; 154 (1): 189-195

    Abstract

    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.Retrospective cohort study.University medical center.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.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/m(2) 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).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.

    View details for DOI 10.1177/0194599815611603

    View details for Web of Science ID 000367745700028

  • Maxillomandibular Advancement for Treatment of Obstructive Sleep Apnea: A Meta-analysis. JAMA otolaryngology-- head & neck surgery Zaghi, S., Holty, J. C., Certal, V., Abdullatif, J., Guilleminault, C., Powell, N. B., Riley, R. W., Camacho, M. 2016; 142 (1): 58-66

    Abstract

    Maxillomandibular advancement (MMA) is an invasive yet effective surgical option for obstructive sleep apnea (OSA) that achieves enlargement of the upper airway by physically expanding the facial skeletal framework.To identify criteria associated with surgical outcomes of MMA using aggregated individual patient data from multiple studies.The Cochrane Library, Scopus, Web of Science, and MEDLINE from June 1, 2014, to March 16, 2015, using the Medical Subject Heading keywords maxillomandibular advancement, orthognathic surgery, maxillary osteotomy, mandibular advancement, sleep apnea, surgical, surgery, sleep apnea syndrome, and obstructive sleep apnea.Inclusion criteria consisted of studies in all languages of (1) adult patients who underwent MMA as treatment for OSA; (2) report of preoperative and postoperative quantitative outcomes for the apnea-hypopnea index (AHI) and/or respiratory disturbance index (RDI); and (3) report of individual patient data. Studies of patients who underwent adjunctive procedures at the time of MMA (including tonsillectomy, uvulopalatopharyngoplasty, and partial glossectomy) were excluded.Three coauthors systematically reviewed the articles and updated the review through March 16, 2015. The PRISMA statement was followed. Data were pooled using a random-effects model and analyzed from July 1, 2014, to September 23, 2015.The primary outcomes were changes in the AHI and RDI after MMA for each patient. Secondary outcomes included surgical success, defined as the percentage of patients with more than 50% reduction of the AHI to fewer than 20 events/h, and OSA cure, defined as a post-MMA AHI of fewer than 5 events/h.Forty-five studies with individual data from 518 unique patients/interventions were included. Among patients for whom data were available, 197 of 268 (73.5%) had undergone prior surgery for OSA. Mean (SD) postoperative changes in the AHI and RDI after MMA were -47.8 (25.0) and -44.4 (33.0), respectively; mean (SE) reductions of AHI and RDI outcomes were 80.1% (1.8%) and 64.6% (4.0%), respectively; and 512 of 518 patients (98.8%) showed improvement. Significant improvements were also seen in the mean (SD) postoperative oxygen saturation nadir (70.1% [15.6%] to 87.0% [5.2%]; P < .001) and Epworth Sleepiness Scale score (13.5 [5.2] to 3.2 [3.2]; P < .001). Rates of surgical success and cure were 389 (85.5%) and 175 (38.5%), respectively, among 455 patients with AHI data and 44 (64.7%) and 13 (19.1%), respectively, among 68 patients with RDI data. Preoperative AHI of fewer than 60 events/h was the factor most strongly associated with the highest incidence of surgical cure. Nevertheless, patients with a preoperative AHI of more than 60 events/h experienced large and substantial net improvements despite modest surgical cure rates.Maxillomandibular advancement is an effective treatment for OSA. Most patients with high residual AHI and RDI after other unsuccessful surgical procedures for OSA are likely to benefit from MMA.

    View details for DOI 10.1001/jamaoto.2015.2678

    View details for PubMedID 26606321

  • Large maxillomandibular advancements for obstructive sleep apnea: An operative technique evolved over 30 years. Journal of cranio-maxillo-facial surgery Camacho, M., Liu, S. Y., Certal, V., Capasso, R., Powell, N. B., Riley, R. W. 2015; 43 (7): 1113-1118

    Abstract

    Obstructive sleep apnea (OSA) can be a challenging disorder to treat. Maxillomandibular advancements (MMAs) generally have high success rates; however, larger advancements have higher success and cure rates. Our aim is to present and to describe the current technique used by the senior authors, which has been successful for performing large advancements, thereby improving post-operative outcomes.The senior authors have developed and modified their maxillomandibular advancement operative techniques significantly over the past 30 years. The current version of the Riley-Powell MMA technique is described in a step-by-step fashion in this article.Initially, as part of the MMAs, patients underwent maxillomandibular fixation with wires, lag screws and harvested split calvarial bone grafts. The current technique utilizes plates, screws, Erich Arch Bars, and suspension wires which are left in place for 5-6 weeks. Guiding elastics are worn for the first week. The MMA technique described in this article has yielded a success rate over 90% for patients with a body mass index (BMI) <40 kg/m(2) and 81% for patients with a BMI ≥40 kg/m(2).Large advancements during maxillomandibular advancement surgeries can help improve post-operative obstructive sleep apnea outcomes.

    View details for DOI 10.1016/j.jcms.2015.05.015

    View details for PubMedID 26116307

  • Lateral Pharyngeal Wall Tension After Maxillomandibular Advancement for Obstructive Sleep Apnea Is a Marker for Surgical Success: Observations From Drug-Induced Sleep Endoscopy. Journal of oral and maxillofacial surgery Liu, S. Y., Huon, L., Powell, N. B., Riley, R., Cho, H. G., Torre, C., Capasso, R. 2015; 73 (8): 1575-1582

    Abstract

    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.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 Cronbach's α coefficient, the McNemar test, and the independent Student t test. The P value was set at <.01.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).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.

    View details for DOI 10.1016/j.joms.2015.01.028

    View details for PubMedID 25843814

  • Resting Energy Expenditure in Adults With Sleep Disordered Breathing ARCHIVES OF OTOLARYNGOLOGY-HEAD & NECK SURGERY Kezirian, E. J., Kirisoglu, C. E., Riley, R. W., Chang, E., Guilleminault, C., Powell, N. B. 2008; 134 (12): 1270-1275

    Abstract

    To examine the association between sleep disordered breathing severity and resting energy expenditure (REE).Cross-sectional.University-based academic medical center.Two hundred twelve adults with signs or symptoms of sleep disordered breathing underwent medical history, physical examination, level I attended polysomnography, and determination of REE using an indirect calorimeter.Mean REE.Seventy-one percent (151 of 212) of the study population were male, and the mean (SD) age was 42.3 (12.6) years. The mean (SD) body mass index, calculated as weight in kilograms divided by height in meters squared, was 28.3 (7.3). The mean (SD) apnea-hypopnea index was 25.4 (27.2), and the lowest oxygen saturation during the sleep study was 86.9% (9.5%). The mean (SD) REE was 1763 (417) kcal/d. Analysis of variance and univariate regression analysis showed an association between REE and several measures of sleep disordered breathing severity that persisted after adjustment for age, sex, and self-reported health status in multiple regression analysis. Only REE and the apnea-hypopnea index demonstrated an independent association after additional adjustment for body mass index (or body weight and height separately). This association did not differ between individuals with normal vs elevated body mass index.Sleep disordered breathing severity is associated with REE. Although this association is largely confounded by body weight, there is an independent association with the apnea-hypopnea index.

    View details for PubMedID 19075121

  • Facial skeletal surgery in the management of adult obstructive sleep apnea syndrome CLINICS IN PLASTIC SURGERY Barrera, J. E., Powell, N. B., Riley, R. W. 2007; 34 (3): 565-?

    Abstract

    Obstructive sleep apnea (OSA) remains a significant public health problem because of its neurocognitive sequelae. Additionally, with persistent obstruction, it has an impact on the cardiovascular system, leading to hypertension and cardiac failure as one of its causative or comorbid factors. For the surgeon managing OSA, there is a stepwise sequence of surgical procedures, from improving nasal airflow to facial skeletal maxillary-mandibular advancement, with the cumulative goal of volumetrically increasing the retropharyngeal airway space. Familiarity with conventional orthognathic principles is essential in achieving this goal.

    View details for DOI 10.1016/i.cps.2007.04.010

    View details for Web of Science ID 000249341800018

    View details for PubMedID 17692712

  • Sleepy driver near-misses may predict accident risks SLEEP Powell, N. B., Schechtman, K. B., Riley, R. W., Guilleminault, C., Chiang, R. P., Weaver, E. M. 2007; 30 (3): 331-342

    Abstract

    To quantify the prevalence of self-reported near-miss sleepy driving accidents and their association with self-reported actual driving accidents.A prospective cross-sectional internet-linked survey on driving behaviors.Dateline NBC News website.Results are given on 35,217 (88% of sample) individuals with a mean age of 37.2 +/- 13 years, 54.8% women, and 87% white. The risk of at least one accident increased monotonically from 23.2% if there were no near-miss sleepy accidents to 44.5% if there were > or = 4 near-miss sleepy accidents (P < 0.0001). After covariate adjustments, subjects who reported at least one near-miss sleepy accident were 1.13 (95% CI, 1.10 to 1.16) times as likely to have reported at least one actual accident as subjects reporting no near-miss sleepy accidents (P < 0.0001). The odds of reporting at least one actual accident in those reporting > or = 4 near-miss sleepy accidents as compared to those reporting no near-miss sleepy accidents was 1.87 (95% CI, 1.64 to 2.14). Furthermore, after adjustments, the summary Epworth Sleepiness Scale (ESS) score had an independent association with having a near-miss or actual accident. An increase of 1 unit of ESS was associated with a covariate adjusted 4.4% increase of having at least one accident (P < 0.0001).A statistically significant dose-response was seen between the numbers of self-reported sleepy near-miss accidents and an actual accident. These findings suggest that sleepy near-misses may be dangerous precursors to an actual accident.

    View details for PubMedID 17425230

  • Incidence of complications in radiofrequency treatment of the upper airway LARYNGOSCOPE Kezirian, E. J., Powell, N. B., Riley, R. W., Hester, J. E. 2005; 115 (7): 1298-1304

    Abstract

    To investigate the incidence of complications after temperature-controlled radiofrequency (TCRF) treatment of the inferior turbinates, palate, and tongue. To compare these complication rates with those reported in the literature.Prospective, observational study.All patients treated with TCRF to the inferior turbinates, palate, and tongues during a 12-month period were included. Data were collected for parameters of energy delivery and the development of complications.One hundred thirty-six patients were treated with a total of 470 TCRF lesions. The overall incidence of minor complications was 1.2% (6/470 lesions); there were no complications of moderate or major severity.The incidence of minor complications after TCRF in this series was low, and there were no complications of greater severity. These findings are in stark contrast with some previously published papers with higher complication rates. These significantly higher rates may be caused by a marked learning curve, problems in patient selection and the technique of application, excessive energy delivery, and perioperative management.

    View details for DOI 10.1097/01.MLG.0000165373.78207.BF

    View details for Web of Science ID 000230329600028

    View details for PubMedID 15995525

  • Complications of obstructive sleep apnea surgery. Oral and maxillofacial surgery clinics of North America Li, K. K., Riley, R., Powell, N. 2003; 15 (2): 297-304

    View details for PubMedID 18088682

  • Postoperative management of the obstructive sleep apnea patient. Oral and maxillofacial surgery clinics of North America Li, K. K., Powell, N., Riley, R. 2002; 14 (3): 401-404

    View details for PubMedID 18088642

  • Radiofrequency thermal ablation therapy for obstructive sleep apnea. Oral and maxillofacial surgery clinics of North America Li, K. K., Powell, N., Riley, R. 2002; 14 (3): 359-363

    View details for PubMedID 18088637

  • Comparison of postoperative pain between laser-assisted uvolopalatoplasty, uvulopalatopharyngoplasty, and radiofrequency volumetric tissue reduction of the palate 102nd Annual Meeting of the American-Academy-of-Otolaryngology-Head-and-Neck-Surgery Troell, R. J., Powell, N. B., Riley, R. W., Li, K. K., Guilleminault, C. MOSBY-ELSEVIER. 2000: 402–9

    Abstract

    This study compares the posttreatment discomfort between laser-assisted uvulopalatoplasty (LAUP), uvulopalatopharyngoplasty (UPPP), and radiofrequency volumetric tissue reduction (RFVTR) of the palate through the use of visual analog pain scales and a quantitative assessment of the analgesic medication taken.In one group, LAUP (n = 10) or UPPP (n = 9) was used to treat patients' snoring or sleep-disordered breathing (SDB), and the other group underwent RFVTR (n = 22).The mean numbers of days with pain after RFVTR, LAUP, and UPPP were 2.6, 13.8, and 14.3 days, respectively. Narcotic analgesics were required in the RFVTR, LAUP, and UPPP groups in 9%, 100%, and 100% of the subjects, respectively. The mean number of these days requiring narcotic pain medications for RFVTR, LAUP, and UPPP was 0.2, 11.8, and 12.4 days, whereas the total narcotic equivalent was 0.3, 7.4 and 29.6 days, respectively.RFVTR of the soft palate produced less posttreatment pain than LAUP or UPPP. LAUP and UPPP appeared to show little difference in the severity or duration of posttreatment discomfort.

    View details for PubMedID 10699818

  • Surgery and obstructive sleep apnea: Long-term clinical outcomes 102nd Annual Meeting of the American-Academy-of-Otolaryngology-Head-and-Neck-Surgery Riley, R. W., Powell, N. B., Li, K. K., Troell, R. J., Guilleminault, C. MOSBY-ELSEVIER. 2000: 415–21

    Abstract

    Outcome data on the surgical treatment of obstructive sleep apnea are, in general, based on short-term follow-up (<6-9 months). This examination was undertaken to assess long-term results.Forty patients who underwent soft tissue and skeletal surgery were the subjects of this review. Methods of evaluation included polysomnographic variables (respiratory disturbance index [RDI], low oxyhemoglobin desaturation [LSAT]), body mass index, quality-of-life assessments, roentgenographic analysis, and complications. Statistical analysis used the SAS 6.12 system.Thirty-six of 40 patients (90%) showed long-term clinical success. The mean preoperative RDI, nasal continuous positive airway pressure RDI, and long-term RDI were 71.2 +/- 27.0, 7.6 +/- 5.2 and 7.6 +/- 5.1, respectively. The mean preoperative LSAT, nasal continuous positive airway pressure LSAT, and long-term LSAT were 67. 5% +/- 14.8%, 87.1% +/- 3.2%, and 86.3% +/- 3.9%, respectively. The mean follow-up was 50.7 +/- 31.9 months. The patients showed a statistically significant long-term weight gain (P = 0.0002) compared with their 6-month postoperative level (body mass index 31. 4 +/- 6.7 vs 32.2 +/- 6.3). There was a positive correlation with the amount of skeletal advancement and clinical outcome.Comprehensive evaluation and surgical treatment can result in successful long-term clinical outcome.

    View details for PubMedID 10699820

  • Evaluation of a new procedure for nasal alar rim and valve collapse: Nasal alar rim reconstruction 102nd Annual Meeting of the American-Academy-of-Otolaryngology-Head-and-Neck-Surgery Troell, R. J., Powell, N. B., Riley, R. W., Li, K. K. MOSBY-ELSEVIER. 2000: 204–11

    Abstract

    A new operative technique to improve nasal valve collapse by placement of cartilage struts along the alar rim was compared with the standard nasal valve cartilage graft (NVG) technique. Methods And Patients: A retrospective study of consecutive patients with nasal valve collapse was performed at Stanford University Medical Center. Seventy-nine patients with nasal valve collapse underwent reconstruction with either the classic NVG technique or a newly developed nasal alar rim reconstructive (NARR) procedure. The mean age of the NARR group was 50.13 years (SD +/- 9.40), with 36 men (92.3%) and 3 women (7.7%). The mean age of the NVG group was 52. 14 years (SD +/- 10.83), with 36 men (90%) and 4 women (10%). Main Outcome Measures: These included functional and subjective evaluation of nasal valve collapse.Forty patients (50.6%) underwent the NVG technique, and 39 (49.4%) received the NARR procedure. The NVG technique revealed 0% worsened, 15.0% (6/40) unchanged, 25.0% (10/40) improved, and 60% (24/40) free of obstruction. The NARR procedure revealed 2.6% worsened, 2.6% unchanged, 7.7% improved, and 87.1% free of obstruction.Nasal alar cartilage struts placed along the caudal alar rim offers sufficient support to the alar rim and valve area. This procedure appears to be as effective as currently available reconstructive alternatives, while being technically uncomplicated.

    View details for Web of Science ID 000085158200009

    View details for PubMedID 10652391

  • Long-Term Results of Maxillomandibular Advancement Surgery. Sleep & breathing = Schlaf & Atmung Li, K. K., Powell, N. B., Riley, R. W., Troell, R. J., Guilleminault, C. 2000; 4 (3): 137-140

    Abstract

    Surgery is a major modality in the treatment of obstructive sleep apnea syndrome (OSAS), and maxillomandibular advancement (MMA) has been shown to be the most effective surgical option. However, despite the successful short-term (6-9 months) results reported by various investigators, little is known of the long-term clinical outcomes. A review of our long-term clinical results demonstrated that MMA achieves long-term cure in most patients. Aging and minor weight gain did not appear to have a significant adverse effect on the long-term results; however, major weight gain did seem to have a significant negative impact on the long-term outcomes. Therefore, long-term follow-up with proper counseling on weight maintenance or reduction is essential in improving long-term results.

    View details for PubMedID 11868133

  • Surgical management of the hypopharyngeal airway in sleep disordered breathing OTOLARYNGOLOGIC CLINICS OF NORTH AMERICA Troell, R. J., Riley, R. W., Powell, N. B., Li, K. 1998; 31 (6): 979-?

    Abstract

    The etiology of sleep disordered breathing is collapse or obstruction of the upper airway during sleep. This obstruction may be localized to one or two areas or may encompass the entire upper airway passages to include the nasal cavity, nasopharynx, oropharynx, hypopharynx, and larynx. The presurgical evaluation, which includes polysomnography, a comprehensive head and neck physical examination, fiberoptic nasopharyngoscopy, and lateral cephalometric analysis is essential in directing surgical therapy in a site specific approach. The surgical procedures available to address hypopharyngeal and base of the tongue collapse include inferior sagittal mandibular osteotomy and gengioglossus advancement, hyoid myotomy and suspension, laser midline glossectomy, lingualplasty, partial glossectomy, and maxillomandibular advancement surgery. The Riley-Powell-Stanford Surgical Protocol has proven to be an effective and safe method for controlling upper airway collapse in sleep disordered breathing.

    View details for Web of Science ID 000077929000006

    View details for PubMedID 9838012

  • Long-term results of surgical management of sleep disordered breathing - Are our patients really benefiting? OTOLARYNGOLOGIC CLINICS OF NORTH AMERICA Troell, R. J., Riley, R. W., Powell, N. B., Li, K. 1998; 31 (6): 1031-?

    Abstract

    The etiology of sleep disordered breathing (SDB), which includes upper airway resistance syndrome (UARS) and obstructive sleep apnea syndrome (OSAS), is collapse or obstruction of the upper airway during sleep. Surgical management was the first treatment modality available for SDB. Since the introduction of the tracheotomy to treat OSAS, there have been numerous procedures discovered to address the various sites of obstruction of the upper airway. This article reviews the long-term surgical results and may improve one's insight into the successes of surgical therapy for SDB.

    View details for Web of Science ID 000077929000009

    View details for PubMedID 9838015

  • Surgical management of obstructive sleep apnea syndrome CLINICS IN CHEST MEDICINE Powell, N. B., Riley, R. W., Robinson, A. 1998; 19 (1): 77-?

    Abstract

    This article discusses the history of operative management of obstructive sleep apnea syndrome and reviews a protocol for surgical intervention. An overview of diagnostic procedures and evaluation is also presented, and emerging technology for the management of this disorder is touched on.

    View details for Web of Science ID 000072887900007

    View details for PubMedID 9554219

  • Hypopharyngeal airway surgery for obstructive sleep apnea syndrome SEMINARS IN RESPIRATORY AND CRITICAL CARE MEDICINE Troell, R. J., Powell, N. B., Riley, R. W. 1998; 19 (2): 175-183
  • MAXILLOFACIAL SURGERY AND OBSTRUCTIVE SLEEP-APNEA SYNDROME OTOLARYNGOLOGIC CLINICS OF NORTH AMERICA Riley, R. W., Powell, N. B. 1990; 23 (4): 809-826

    Abstract

    Maxillofacial surgery has proven to be an effective method for controlling OSA syndrome, and its results are as effective as those obtained with nasal CPAP. The presurgical evaluation, which includes polysomnography, physical examination, fiberoptic pharyngoscopy, and cephalometric analysis, is essential in directing surgical therapy. With phased reconstruction of the upper airway there is an excellent chance of correcting the obstructive process and eliminating the associated problems of OSA syndrome.

    View details for Web of Science ID A1990DQ46800019

    View details for PubMedID 2381716

  • MAXILLARY, MANDIBULAR, AND HYOID ADVANCEMENT FOR TREATMENT OF OBSTRUCTIVE SLEEP-APNEA - A REVIEW OF 40 PATIENTS JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY Riley, R. W., Powell, N. B., Guilleminault, C. 1990; 48 (1): 20-26

    Abstract

    Forty patients with documented obstructive sleep apnea syndrome (OSAS) were evaluated following maxillary and mandibular osteotomies (MMO). All patients were evaluated before and after surgery by a physical examination, fiberoptic pharyngoscopy, cephalometric analysis, and polysomnography. Ninety-seven percent of the patients responded to the surgical treatment, based on the polysomnogram. The present indications for MMO are severe OSAS, morbid obesity, and severe mandibular deficiency.

    View details for PubMedID 2294208

  • MAXILLOMANDIBULAR ADVANCEMENT SURGERY IN 23 PATIENTS WITH OBSTRUCTIVE SLEEP-APNEA SYNDROME - DISCUSSION JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY Riley, R. W. 1989; 47 (12): 1262-1262
  • MAXILLOFACIAL SURGERY AND OBSTRUCTIVE SLEEP-APNEA - A REVIEW OF 80 PATIENTS OTOLARYNGOLOGY-HEAD AND NECK SURGERY Riley, R. W., Powell, N. B., Guilleminault, C. 1989; 101 (3): 353-361

    Abstract

    To determine the effectiveness of the surgical treatment of obstructive sleep apnea, we retrospectively evaluated 80 patients. One group consisted of 55 patients who had undergone a limited osteotomy of the anterior mandible: inferior sagittal osteotomy with hyoid myotomy and suspension. Important criteria for the selection of these patients were normal pulmonary function, normal mandibular skeletal development, and the absence of morbid obesity. Polysomnography revealed that 37 patients (67%) had responded to the surgical treatment and 18 patients (33%) had not. The second group of 25 patients, selected for morbid obesity, severe mandibular deficiency, and failure of other surgical procedures, had undergone maxillomandibular osteotomy with hyoid advancement. All patients in the second group showed good results, as determined by polysomnography.

    View details for PubMedID 2508006

  • INFERIOR MANDIBULAR OSTEOTOMY AND HYOID MYOTOMY SUSPENSION FOR OBSTRUCTIVE SLEEP-APNEA - A REVIEW OF 55 PATIENTS JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY Riley, R. W., Powell, N. B., Guilleminault, C. 1989; 47 (2): 159-164

    Abstract

    Fifty-five patients with obstructive sleep apnea syndrome (OSAS) were evaluated following inferior mandibular osteotomy with hyoid myotomy and suspension. Patients were objectively examined by polysomnography before and 6 months following the surgical procedure. Thirty-seven patients (67%) had a good response from surgery, and 18 patients (33%) were considered nonresponders. Lung disease, mandibular deficiency, and obesity were factors found to affect the success of surgical treatment.

    View details for PubMedID 2913251

  • OBSTRUCTIVE SLEEP-APNEA SYNDROME FOLLOWING SURGERY FOR MANDIBULAR PROGNATHISM JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY Riley, R. W., Powell, N. B., Guilleminault, C., Ware, W. 1987; 45 (5): 450-452

    View details for Web of Science ID A1987H205900015

    View details for PubMedID 3471930

  • CURRENT SURGICAL CONCEPTS FOR TREATING OBSTRUCTIVE SLEEP-APNEA SYNDROME JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY Riley, R. W., Powell, N., Guilleminault, C. 1987; 45 (2): 149-157

    Abstract

    Obstructive sleep apnea syndrome is a relatively common disorder with potentially serious psychologic and physiologic consequences. A comprehensive method of evaluation is described. Presurgical tests are mandatory in order to logically direct surgical treatment. Current surgical treatment and new techniques are discussed.

    View details for Web of Science ID A1987F974600011

    View details for PubMedID 3468216

  • INFERIOR SAGITTAL OSTEOTOMY OF THE MANDIBLE WITH HYOID MYOTOMY-SUSPENSION - A NEW PROCEDURE FOR OBSTRUCTIVE SLEEP-APNEA OTOLARYNGOLOGY-HEAD AND NECK SURGERY Riley, R. W., Powell, N. B., Guilleminault, C. 1986; 94 (5): 589-593

    Abstract

    Five patients were treated by inferior sagittal osteotomy and hyoid myotomy-suspension. In three of the patients, palatopharyngoplasty had previously failed. One of the patients was noted to have mandibular deficiency; the others had normal skeletal development. Nocturnal polysomnograms were performed preoperatively and postoperatively. All patients showed significant improvement.

    View details for Web of Science ID A1986C850700010

    View details for PubMedID 3088521

  • MAXILLARY, MANDIBULAR, AND HYOID ADVANCEMENT - AN ALTERNATIVE TO TRACHEOSTOMY IN OBSTRUCTIVE SLEEP-APNEA SYNDROME OTOLARYNGOLOGY-HEAD AND NECK SURGERY Riley, R. W., Powell, N. B., Guilleminault, C., NINOMURCIA, G. 1986; 94 (5): 584-588

    Abstract

    Nine patients with severe obstructive sleep apnea syndrome (OSAS)--for whom several therapeutic approaches, including palatopharyngoplasty, had failed--were treated with a combined maxillary, mandibular, and hyoid advancement. Objective evaluation--performed before and 4 to 18 months after surgery, using nocturnal polysomography--indicated that the OSAS had improved or had disappeared. This surgical approach is beneficial for specific cases of OSAS, which can be identified by mandatory presurgical tests.

    View details for Web of Science ID A1986C850700009

    View details for PubMedID 3088520

  • PALATOPHARYNGOPLASTY FAILURE, CEPHALOMETRIC ROENTGENOGRAMS, AND OBSTRUCTIVE SLEEP-APNEA OTOLARYNGOLOGY-HEAD AND NECK SURGERY Riley, R., Guilleminault, C., Powell, N., SIMMONS, F. B. 1985; 93 (2): 240-244

    Abstract

    Nine patients with obstructive sleep apnea who underwent unsuccessful palatopharyngoplasty (PPP) as documented by polygraphic monitoring had abnormal cephalometric roentgenogram measurements. Findings indicated a small posterior airway space and inferiorly placed hyoid bone. Cephalometry performed with appropriate techniques to investigate soft tissue location should be obtained systematically in obstructive sleep apneic patients before any surgery is performed. The roentgenogram finding is a helpful guide in deciding whether PPP alone or PPP in combination with other surgical procedures would be more efficacious.

    View details for Web of Science ID A1985AGY1600021

    View details for PubMedID 3921918

  • MANDIBULAR OSTEOTOMY AND HYOID BONE ADVANCEMENT FOR OBSTRUCTIVE SLEEP-APNEA - A CASE-REPORT SLEEP Riley, R., Guilleminault, C., Powell, N., Derman, S. 1984; 7 (1): 79-82

    Abstract

    A 24-year-old man with obstructive sleep apnea syndrome and secondary daytime somnolence and nocturnal arrhythmias underwent palatopharyngoplasty. When he did not improve significantly, he underwent a new surgical procedure combining hyoid bone and mandibular horizontal sliding osteotomy.

    View details for Web of Science ID A1984SJ30900009

    View details for PubMedID 6718928

  • MANDIBULAR ADVANCEMENT AND OBSTRUCTIVE SLEEP-APNEA SYNDROME BULLETIN EUROPEEN DE PHYSIOPATHOLOGIE RESPIRATOIRE-CLINICAL RESPIRATORY PHYSIOLOGY Powell, N., Guilleminault, C., Riley, R., Smith, L. 1983; 19 (6): 607-610

    Abstract

    A surgical procedure performed to advance the mandible in patients with retrognathia and obstructive sleep apnea is described. The case history of an obese patient with severe sleep apnea problems who underwent a number of treatments, responding only to mandibular advancement, is presented.

    View details for Web of Science ID A1983TQ64600017

    View details for PubMedID 6652268

  • SQUAMOUS-CELL CARCINOMA OF THE BASE OF THE TONGUE OTOLARYNGOLOGY-HEAD AND NECK SURGERY Riley, R. W., Fee, W. E., Goffinet, D., Cox, R., Goode, R. L. 1983; 91 (2): 143-150

    Abstract

    The squamous cell carcinomas of 119 patients treated between 1958 and 1980 were retrospectively reclassified according to the 1977 American Joint Committee for Cancer Staging-End Results Reporting guidelines. Analysis of the information was performed with an interactive computer program that allows the analysis of a large number of medical factors with numerous variables. The following factors show the statistically significant improved survival rates: well-differentiated histopathologic findings, small T-stage lesions, and clinically negative neck disease. Although the survival curve was similar in the planned combined therapy and radiation therapy groups, local control was statistically superior in the combined therapy group. A similar trend is seen in those patients who receive interstitial implants in addition to external beam therapy. A randomized prospective study is needed to determine the optimum mode of therapy.

    View details for Web of Science ID A1983QM63500006

    View details for PubMedID 6408570