Systematic Review of The Effect of Upper Airway Surgery Based on DISE Findings In Adults With Obstructive Sleep Apnea
Authors: Bertelsen Jannik Buus , Ovesen Therese , Zainali-Gill Kasra 
Published: September 2021

Abstract
The objective of this review is to evaluate the effectiveness of upper airway surgery in adults with OSA verified on Drug Induced Sedation Endoscopy (DISE) and evaluated by change in AHI with minimum 3 month´s follow-up. Introduction: Obstructive sleep apnea (OSA) is common among adults worldwide and is associated with an increased risk of cardiac and metabolic disease. However, the evidence of the different types of upper airway surgery to relieve OSA symptoms are sparse. Inclusion criteria:Inclusion criteria for this review were randomized controlled trials, prospective and retrospective studies case-control studies and cohort studies on one or a combination of surgeries on the upper airways in adults diagnosed with OSA and obstruction verified by DISE before surgery. AHI should be reported prior to and minimum 3 months after surgery by polysomnography or home sleep apnea test and a minimum of 40 participants published from year 2000 to December 2019. All surgeries in upper airways including soft tissue of the retropharyngeal space, velum, tonsils and base of tongue were included. Surgeries on cartilage and bone as septoplasty, turbinoplasty, mandibular advancement surgery, epiglottoplasty and tracheostomy were included plus hypoglossal nerve stimulation implant.Exclusion criteria were reviews supplying no data, case reports and studies reporting treatment mandibular advancement devices or position trainer. Surgeries targeting other anatomical sites than upper airways with a known reduction in AHI as bariatric surgery were also excluded. Studies without pre-operative DISE were excluded. Publications in other language than English were excluded.Methods: Cochrane, PubMed, CINAHL and Embase were systematically searched on December 12th, 2019. Abstracts in languages other than English were deselected. Relevant studies were selected on their abstracts and full texts were obtained for critical appraisal. Relevant data were extracted for data synthesis. The reference list of all studies selected for critical appraisal was screened for additional studies.Results (For Reviews ONLY): Studies were excluded due to small sample size, lack of postoperative AHI and because DISE was not a part of preoperative evaluation. Ten studies were finally included for review. These could be divided into three segments, comprised by three studies for surgeries of the velum and oropharynx, four studies addressing the base of tongue (BOT) and three studies in multi-level surgery. Velum and oropharynx surgery led to an AHI-decrease of 11.86, 95% CI (10.21; 13.51) event per hour. ESS was reduced 7.01 (5.99; 8.04). In BOT surgery AHI was reduced 19.31 (17.81;20.81) events/hour and ESS decreased with 7.03 (6.44; 7.63). Multilevel surgery reduced AHI with 28.65 (24.60, 32.69) events/hour and ESS with 8.55 (6.73; 10.38).Conclusions:Our review indicated that incorporating DISE in the preoperative evaluation of OSA patients, improved the selection of patients for specific upper airway surgeries, causing a better surgical outcome measured by a reduction in AHI and ESS. We found the literature to be primarily comprised of case series with few numbers of patients and a wide variety of approaches to pre-operative evaluation and post-operative follow up.