ORIGINAL ARTICLE Hypopharyngeal Surgery in Obstructive Sleep Apnea An Evidence-Based Medicine Review Eric J. Kezirian, MD, MPH; Andrew N. Goldberg, MD, MSCE Objective: To perform an evidence-based medicine re- Results: We identified 36 articles. These were primarily view of the literature describing outcomes of hypopha- case series studies (level 4 evidence), although some stud- ryngeal surgery in obstructive sleep apnea. ies provided levels 1 and 2 evidence. Hypopharyngeal sur- gery demonstrates improvements in respiratory physiol- Design: We performed a MEDLINE search of English- ogy during sleep, daytime somnolence, and quality of life. language articles or abstracts using the keywords sleep Severalfactorssuchasthebodymassindex,apnea-hypopnea and surgery in combination with any of the following index, Friedman stage, and SNB angle on lateral cepha- terms: hypopharynx, tongue, tongue base, epiglottis, genio- logram have been associated with surgical outcomes. Con- glossus, advancement, mortised, genioplasty, glossectomy, sidering the improvement in respiratory physiology alone, tongue radiofrequency, hyoepiglottoplasty, hyoid, suspen- successful outcomes are achieved in 35% to 62% of patients; sion, and stabilization. Additional studies were identi- certain subgroups achieve higher success rates. fied from their reference lists. We reviewed abstracts to select publications reporting outcomes of hypopharyn- Conclusions: Hypopharyngeal surgery in obstructive geal surgery in obstructive sleep apnea. Articles were in- sleep apnea is associated with improved outcomes, al- cluded only if patients underwent treatment of the pal- though this benefit is supported largely by level 4 evi- ate for suspected retropalatal obstruction. dence. Future research should include larger, higher- level studies that consider the variety of treatment effects, Data Extraction: Evidence-based medicine review for compare surgical treatments, and identify factors asso- level of evidence, preoperative patient characteristics, sur- ciated with outcomes. gical outcomes, and patient-specific factors associated with outcomes. Arch Otolaryngol Head Neck Surg. 2006;132:206-213 LANNING FOR SURGICAL (with response defined as a 50% decrease treatment of obstructive sleep in the respiratory disturbance index and a apnea (OSA) begins with postoperative respiratory disturbance in- evaluation to determine the dex of Ͻ20, or as a 50% decrease in the ap- most likely site(s) of airway nea index and a postoperative apnea index Pnarrowing or collapse. By functionally di- of Ͻ10) in patients with OSA treated with viding the pharynx into the retropalatal uvulopalatopharyngoplasty alone, regard- (corresponding to the portion of the oro- less of site of obstruction. In patients with pharynx at the level of the soft palate and suspected retropalatal narrowing alone (type tonsils) and the so-called hypopharyn- I obstruction), the response rate increased geal (actually corresponding to both the to 52.3%, but for those with a component portion of the oropharynx at the level of of hypopharyngeal obstruction (types II and the tongue base and the hypopharynx) re- III), the response rate was only 5.3%.4 gions, Fujita and Simmons1 described the In the years since the publication of that following 3 patterns of obstruction: type literature review,4 several procedures have I, retropalatal obstruction alone; type II, been developed to achieve higher re- both retropalatal and hypopharyngeal sponse rates in patients with hypopharyn- obstruction; and type III, hypopharyn- geal obstruction, and multiple studies have geal obstruction alone. reported the results of the new and older In 1981, Fujita et al2 described uvulo- procedures. The procedures available to palatopharyngoplasty as a treatment for pa- treat hypopharyngeal obstruction in OSA tients with retropalatal airway obstruc- include genioglossus advancement, mor- Author Affiliations: Department of tion. Although highly effective for simple tised genioplasty, tongue radiofrequency Otolaryngology–Head and Neck snoring, with a control rate ranging from treatment, surgical reduction of the tongue Surgery, University of 75% to 87%,3 a literature review by Sher et base (midline glossectomy), hyoepiglotto- California–San Francisco. al4 showed an overall response rate of 40.7% plasty, hyoid suspension, and tongue base (REPRINTED) ARCH OTOLARYNGOL HEAD NECK SURG/ VOL 132, FEB 2006 WWW.ARCHOTO.COM 206 ©2006 American Medical Association. All rights reserved. Downloaded From: http://archotol.jamanetwork.com/ by a University of California - Los Angeles User on 03/19/2014 stabilization. These procedures can be performed alone or ment, mortised, genioplasty, glossectomy, tongue radiofre- in combination under the same anesthetic. The specific quency, hyoepiglottoplasty, hyoid, suspension, and stabilization. description of the technical aspects of these procedures is We reviewed abstracts to select publications reporting out- beyond the scope of this report, but multiple studies5-41 comes of hypopharyngeal surgery in patients with OSA. We iden- have shown that these procedures improve outcomes in tified additional publications from the lists of references in this subset of articles. Articles were reviewed only if patients un- patients with suspected types II and III obstruction. 42 derwent treatment of the palate when retropalatal obstruction Sackett et al outlined many of the foundations of was suspected. present-day evidence-based medicine, which they de- All studies were reviewed for the following information: scribed as “the integration of [the] best research evi- v dence with clinical expertise and patient values.”42(p1) To Preoperative characteristics of patient populations, such as body mass index (BMI) (calculated as weight in kilograms describe the quality of research evidence, a hierarchy has divided by the square of height in meters) and preoperative sleep been developed that assigns each study a level of evi- study results such as the reported apnea-hypopnea index (AHI) dence based on the study design and the quality of the and lowest oxygen saturation (LSAT) during sleep 43 study. The following tabulation presents the study de- v Postoperative sleep study results, such as AHI and LSAT signs that correspond to the 5 levels of evidence. v Surgical success, defined by the most common criteria of Level of Evidence Study Design sleep study results (ie, a reduction in AHI of 50% or more and an AHI of less than 20) 1 Randomized, controlled trial v 2 Cohort study Any factors (eg, preoperative BMI or AHI) that were as- sociated with outcomes 3 Case-control study v 4 Case series Improvement in daytime somnolence, measured by the 44 5 Expert opinion Epworth Sleepiness Scale v Improvement in quality of life, measured as sleep-related quality of life (using the Functional Outcomes of Sleep Ques- This tabulation is simplified because there is a great tionnaire45 or the Symptoms of Nocturnal Obstruction and Re- deal of overlap between study designs and levels of evi- lated Events46 questionnaire) or global health-related quality dence as well as subgroups within the levels that reflect of life (based on the 36-Item Short-Form Health Survey47) the quality of the study and data analysis. v Level of evidence Evidence-based medicine combines studies (based on We then compared the results for each procedure or com- their levels of evidence) to develop treatment recommen- bination of procedures according to the criteria for a success- dations. The strength of these recommendations is based ful surgical outcome as outlined. We used the ␹2 test to deter- 43 on the quality of the available evidence. The following mine whether there was a difference in the share of patients tabulation presents the grades that correspond to the lev- with a successful outcome among treatments, and PϽ.05 was els of evidence on which the recommendations are based. considered statistically significant. Grade of Levels of Evidence Supporting Recommendation Recommendation* RESULTS A Consistent level 1 B Consistent level 2 or 3 or extrapolation from level 1 We identified a total of 36 studies. Many studies did not C Level 4 or extrapolation from level 2 or 3 D Level 5 or troubling, inconsistent, or report or did not consider some of the information we inconclusive studies of any level of outlined in the “Methods” section. Thirty-four (94%) of evidence the 36 studies were case series and therefore provided *Levels of evidence are described in the preceding tabulation. level 4 evidence. Patients undergoing genioglossus advancement as the Evidence-based medicine is commonly misinter- sole treatment of hypopharyngeal airway obstruction preted as a technique that ignores all studies except the (Table 1) demonstrated, on average, severe OSA before randomized controlled trial (level 1 evidence); al- surgery.5-8 After the procedure, there was significant im- though high-quality randomized controlled trials re- provement in the AHI in the 3 series that reported aggre- ceive the most weight in an evidence-based medicine re- gate group data. Using the criteria for success based on AHI view, all available studies are explicitly included in the results, 3 studies6-8 reported success rates of more than 60%; development of treatment recommendations. Again, clini- 1 series5 had a lower rate. The 2 studies that considered cal decisions will ultimately be based on clinical exper- the LSAT also showed an improvement in this metric. tise and patient values as well as this evidence. One report9 presented