Although PSG is the gold standard for the diagnosis of OSA, it does not provide information in regard to the location of obstruction. A pre-surgical patient evaluation includes a physical examination and a flexible fiberoptic nasopharyngoscopy to evaluate the upper airway to identify potential sites of collapse. Several other diagnostic modalities have showed some value to supplement a physical examination, including lateral cephalogram, 3-dimensional cone beam computed tomographic scan, sleep endoscopy, or cine-magnetic resonance imaging (MRI) [11
]. The last 2 have been shown some promise because they evaluate static and dynamic aspects of the upper airway while asleep or in a sleep-like state.
Sleep endoscopy involves only mild sedation with a hypnotic drug, such as midazolam or propofol. A flexible fiberoptic endoscope is then introduced nasally and oropharyngeal and hypopharyngeal areas are observed for collapse [12
]. This examination is advantageous because it of the dynamics of being performed while the patient is in a sleep state, and therefore it reproduces what may be occurring while the patient is asleep. Drug induced sleep endoscopy has been shown to be a valid assessment of the upper airway, with moderate-to-substantial test-retest reliability and moderate-to-substantial inter-rater reliability. It allows the evaluation of the airway in a situation as close to sleep as possible [14
]. Sleep MRI has the advantage of evaluating the airway without the presence of instruments within its lumen, and in a stage of natural sleep, allowing a dynamic characterization of the levels of obstruction, as it captures real-time images that create a “movie.” It has shown very high coefficients of intra- and inter-rater reliability for the determination of presence or absence of obstruction [16
]. Sleep MRI is still being investigated as a diagnostic tool, and further methodological improvement will be necessary before considering its widespread use.
Both examinations are commonly used to evaluate surgical failures to identify residual sites of obstruction, or are used in complex cases in which the history and/or PSG do not appear to match the patient’s symptoms. These tools should be used to help inform our clinical/surgical decision-making to better counsel patients.
As previously mentioned, every patient should be offered a CPAP trial prior to surgery. In addition to being the most conservative approach, it may be helpful as a noninvasive means to determine the likelihood of improvement of symptoms after surgery, and to minimize the chance of perioperative complications [17
]. In addition, patient counseling should also include behavioral modifications, such as weight loss, diet, physical exercise, positional therapy, and avoidance of sedatives, regardless of the treatment option chosen [18
Surgical treatment can be considered once a patient has failed CPAP therapy, despite counseling and correction of common CPAP issues. An exception is when the patient has an identifiable physical abnormality, such as enlarged tonsils or a severely deviated septum. A key to effective surgical therapy involves determining sites of airway obstruction or narrowing, interpreting a patient’s PSG data, and understanding which surgical procedures are appropriate for each patient. Synthesizing all the data helps develop a specific plan, as each patient is unique. Equally important is recognizing that not every patient will be a good surgical candidate due to the patient’s sleep physiology or anatomy or comorbidities. Therefore, it is paramount to have a good understanding sleep medicine, sleep surgery, and general medicine.
Surgery should only be undertaken after comprehensive patient counseling has occurred. Counseling includes discussion of potential sites of obstruction, and surgical, as well as nonsurgical, treatment options. If additional diagnostic testing is recommended, the purpose and goals of these additional tests should be discussed with the patient. Even if surgery is being considered as the primary treatment option, CPAP and other conservative therapies should still be considered.
Bearing in mind that OSA is a disease with severe complications abiding considerable perioperative risk, certain measures are necessary when considering surgical treatment. Complications include higher intubation rates, hypercapnia, oxygen desaturation, cardiac arrhythmias, necessity of intensive care unit transfer and others. The anesthetic effect can linger for several days after the surgery, and therefore caution with opioid agents is extremely important. Considering these patients have suboptimal airways and surgery is performed in the airway, monitoring for respiratory events and oxygen saturation is advised, preferably in the intensive care unit. The use of CPAP therapy is recommended both preoperatively and postoperatively [19