OSAHS is a common disorder that has many serious implications. Although the etiology of this disorder is not fully understood, it is clear that collapsing tissue at multiple levels of the upper airway occlude the airway during sleep. Since it was first described 1981, CPAP therapy has been the gold standard treatment for this disorder. The most accepted mechanism of action of CPAP is that positive airway pressure acts as a pneumatic splint that anteriorly displaces collapsible tissue, preventing occlusion of the airway. This mechanism is highly effective because it stabilizes all levels of the upper airway, regardless of where the collapse occurs. CPAP therapy has been shown to effectively improve symptoms of OSAHS such as daytime sleepiness, disturbed sleep, and cognition as well as reduce the risks of cardiovascular disease and motor vehicle accidents.
Although it is highly effective, the major weaknesses of CPAP therapy have always been patient acceptance and patient compliance. In a comprehensive review by Engleman in 2003 found that non-acceptance of CPAP varied from approximately 5 to 50% with an average rate of only 20%. Engleman also found that another 12 to 15% can be expected to stop CPAP within 3 years. Even for those who accept CPAP therapy compliance has always remained an issue.
Although the literature suggests that most patients require more than 4 hours of therapy a night, the traditional definition of compliance in the sleep literature is >4 hours of use for 70% of the nights. With this definition, compliance ranges from 40-80% in patients who use CPAP. These issues of acceptance and compliance severely impact the efficacy of CPAP as the definitive treatment for OSAHS. It is clear that the greater than 50% of patients who will not use CPAP need to have safe, effective alternatives that can help ameliorate symptoms of this disorder.
The role of surgery in the treatment algorithm of OSAHS has always been controversial. It is always difficult to justify invasive treatment options with increased morbidity when a non-invasive alternative exists. However, in the case of OSAHS, the refusal of the medical option by patients leaves only the options of doing nothing, or perusing alternative therapy. It is clear that surgical treatment should not be considered without first trying CPAP. Surgical treatment should only be reserved for those patients who refuse CPAP, but are looking for alternative measures to palliate their symptoms.
Surgical correction of OSAHS, unlike CPAP, is site specific. The basic premise of surgical therapy is to remove or stiffen upper airway tissue and prevent its collapse in sleep. As collapse can occur at multiple levels of the upper airway, no single surgical procedure can be expected to correct all patients. Despite this observation, UPPP remains the single most common procedure performed for OSAHS. First introduced in 1981 by Fujita et al, UPPP is a valuable treatment to alleviate obstruction at the level of the soft palate and tonsils; however, this procedure does not address any other site of obstruction. As UPPP is usually the only procedure most surgeons offer for OSAHS, it has become an accepted notion that UPPP and surgical management are synonymous.
The unfortunate drawback to this association is that UPPP, as a single procedure for OSAHS, has a success rate estimated at about 41%, leading many to believe that the surgical treatment is a poor option. However, surgical management of OSAHS has clearly evolved over time. It is now well recognized that the multilevel nature of OSAHS requires attention to multiple sites to achieve complete resolution of symptoms. When tissue is supported throughout the upper airway, collapse becomes far less likely. A recent meta-analysis conducted by Lin et al. has demonstrated that success rate of multilevel surgery in the current literature was as high as 66.4%. As surgical techniques improve this rate is expected to improve. On the hand, every effort needs to also be made to improve the compliance rate of CPAP therapy. There have been reports of achieving compliance rates of up to 80%, but more needs to be accomplished in making results such as this universal.
