What the Evidence Says
One of the challenges that arises when trying to evaluate the success of OSA surgery is the absence of rigorously proven, Level 1 evidence (randomized, placebo-controlled, double-blind clinical trials). Obviously, these studies are not possible when evaluating the success of surgery, because the experience and anatomical evidence of the procedure cannot be concealed from physicians and patients. But there are other types of evidence that can, and should, be considered. Non-randomized and good cohort studies do exist (Level 2 evidence) and would be beneficial. Case studies comparing MMA to CPAP have been done, and the results have been generalizable across sleep centers. The results appear in objective measures, including AHI and oxyhemoglobin nadir, suggesting they are free from any patient bias. Careful review of existing literature can point to the advantages of surgical interventions.
Explore This IssueFebruary 2013
If CPAP treatment is deemed successful only when AHI is reduced to within normal parameters of 5 or less, it can be argued that surgery can only be labeled successful when it accomplishes the same reduction. Numerous studies, including a landmark study by Becker and colleagues published in 2003, have demonstrated that when AHI is at 5 or below, compared with a 50 percent reduction of the AHI, there is significant effect on lowering blood pressure, and therefore a meaningful decrease in cardiovascular risk (Circulation. 2003;107:68-73). Duration of CPAP use is also a factor that should be considered. In the Becker study, the patients were treated for the full night of sleep, an average of seven hours. The CMS definition of adequate CPAP compliance is four hours of usage 70 percent of the nights. This means that a patient who sleeps seven hours a night could be considered compliant with therapy even though treatment is only being received for 40 percent of sleep time. Surgical treatment provides treatment for 100 percent of sleep time.
These data suggest that patients using CPAP, with its higher success threshold, are healthier than those who undergo surgery. However, in 2004, Dr. Weaver published a study comparing mortality outcomes of patients using CPAP to that of patients who had undergone UPPP surgery. Overall, UPPP patients had better survival rates than CPAP patients (Otolaryngol Head Neck Surg. 2004;130:659-665).
It should be noted that all patients who received a CPAP device were included in the study, and there are no data regarding whether they used it regularly or at all. Considering compliance issues with CPAP therapy, it is likely that a significant number of these patients did not use their CPAP adequately and were therefore incompletely treated or untreated. However, surgery patients with partial improvement in AHI status experienced this partial benefit every night. The data suggest that gaining a partial treatment effect every night reduces mortality risk better than sporadic treatment benefits or no treatment at all.