Adult Sleep Apnea Surgery
Obstructive sleep apnea is the result of airway obstruction during sleep. Patients with obstructive sleep apnea either have a smaller airway dimension or a floppy airway with a greater tendency to collapse while sleeping. This creates a disordered sleep-wake cycle each night caused by a repetitive struggle to breathe and oxygen deprivation.
Different surgical procedures have been developed to treat the airway components causing obstructive sleep apnea. The airway pattern and severity of obstruction vary greatly between individuals, which affects the success rate of a given surgical procedure. In general, as the severity of obstructive sleep apnea increases, so does the invasiveness of the required procedure to achieve a successful surgical outcome.
Clearly, prior to any sleep apnea surgery, the diagnosis of obstructive sleep apnea based on sleep study results is essential. Although some may debate whether a formal polysomnography should be mandatory, the use of an ambulatory sleep study is an acceptable practice under current standards. The selection of surgical procedure(s) is based on numerous factors (Table 1). A patient’s desire and preference as well as the health status can clearly influence outcomes and must be taken into consideration. Additionally, the goal of surgery may be different for patients. Although the majority of patients elect surgical treatment due to intolerance of non-surgical treatments, some patients may consider surgery in order to improve their ability to tolerate non-surgical treatments, such as the reduction of therapeutic CPAP pressure or improvement of nasal symptoms due to CPAP use. Therefore, the surgical endpoint should be discussed prior to surgery, along with criteria for surgical success (Table 2). Informed consent must be conducted, and patients should be educated regarding the rationale of surgery as well as associated risks and benefits.
In formulating a surgical plan, the most difficult task for the surgeon is to decide which procedure(s) should be utilized. Indeed, information gathered from the pre-operative assessment, including clinical examination, fiberoptic nasopharyngoscopy and lateral cephalometric radiograph, can provide useful information regarding the upper airway anatomy and the site(s) of obstruction. Nevertheless, the only surgical procedure that has been able to achieve a consistently significant response rate is maxillomandibular advancement. Other surgical procedures that are less invasive are often much less predictable and clearly less successful, especially in patients with severe obstructive sleep apnea. Thus, as the severity of the obstructive sleep apnea increases, so will the invasiveness of the procedures needed to achieve improvement.
Clearly, the most logical surgical approach would be to minimize surgical intervention and avoid unnecessary surgery while achieving a successful result. Therefore, the majority of surgeons have favored a staged surgical protocol. Since uvulopalatopharyngoplasty or uvulopalatal flap and genioglossus/hyoid advancement are all rather limited procedures without significant surgical morbidity, these procedures are usually first attempted to improve obstructive sleep apnea. After a healing period of four to six months, a post-operative polysomnogram is obtained to evaluate outcome. In patients with persistent obstructive sleep apnea, maxillomandibular advancement can then be performed. Uvulopalatopharyngoplast/uvulopalatal flap in combination with genioglussus/hyoid advancement is usually considered as phase I operation, in which these procedures are often performed as a single operation.
Maxillomandibular advancement is considered as phase II operation. However, the staged approach may actually increase unnecessary surgical manipulation for some patients. Patients with factors that can negatively influence the outcome may have a low chance of success with phase I operation (Table 1). Therefore, patients with severe obstructive sleep apnea, morbid obesity or significant hypopharyngeal obstruction such as severe mandibular deficiency, or patients who wish to have the best chance for a cure with a single operation can certainly be considered as candidates for maxillomandibular advancement as a primary surgical treatment option. Clearly, it is important to review all possible treatment options and explain the rationale for sleep apnea surgery. Successful surgical outcome depends on proper patient selection as well as the choice of surgical procedure(s). The adaptation of a logical and systematic approach to clinical evaluation, treatment planning and surgical execution is necessary in order to maximize safety and improve surgical results.
Table 1: Factors influencing sleep apnea surgery outcomes
|Age||Younger patients (< 60 y.o.)||Older patients (> 60 y.o.)|
|OSA severity||Mild to moderate (RDI < 30)||Severe (RDI > 30)|
|Site of obstruction||Oropharyngeal (with tonsils)||Hypopharyngeal|
Table 2: Defining surgical success
- Improvement in quality of life with reduction of sleep apnea symptoms
- Achieving RDI to less than 20 and reducing RDI by greater than 50%
- Improvement of oxygen nadir to 90% with few desaturations to below 90%