Long-Term Survival of Patients With Obstructive Sleep Apnea Treated by Uvulopalatopharyngoplasty or Nasal CPAP – Comment
Uvulopalatopharyngoplasty was proposed as a surgical treatment for OSA by Fujita and associates. The success of this operation varies considerably, and some of this variability has been accounted for by differences in patient selection or surgical technique. Both nasal CPAP and UPPP have been shown to reduce systemic blood pressure in patients with OSA. buy allegra
In contrast to our study, He and associates2 found improved survival in those patients with OSA treated by nasal CPAP or tracheostomy but not in those treated by UPPP when compared with untreated patients. However, there are major differences between the two studies. In the study by He and associates;x2 the patients had more severe OSA, and only 40 percent had a successful surgical outcome compared with 81 percent in our study, using similar criteria to define success. Furthermore, the proportion of patients who underwent follow-up polysomnography after UPPP differs. In the study by He and associates,2 79 percent of patients had follow-up polysomnography compared with 94 percent in our study.
Our study’s design has certain limitations. It, like all previous studies, is retrospective. Prospective controlled clinical studies are required to compare longterm survival between different treatments for OSA. However, such studies would currently be difficult to accomplish because of potential problems with both randomization and blinding. Furthermore, a longterm control untreated group would not be considered ethical as it is generally accepted that OSA is associated with increased mortality and morbidity. The issue of comorbidity confounds our results. The patients treated with nasal CPAP were more obese, and therefore at higher risk for associated systemic hypertension and ischemic heart disease. However, the patients treated with UPPP had more severe OSA, which would tend to counter the effect of increased body weight on mortality in the patients treated with nasal CPAP. Some of our patients were treated with nasal CPAP prior to UPPP and it could be argued that this nasal CPAP therapy had an impact on survival. We believe this is unlikely as the majority of these patients were only treated with nasal CPAP for 1 to 2 months and when we excluded them from the analysis, there was still no significant difference in long-term survival between patients treated with UPPP and nasal CPAP. Finally, the number of deaths was small, and our study may lack the power to establish differences in longterm survival between UPPP and nasal CPAP. Larger long-term studies may be required; however, our numbers are much larger (UPPP, 149 vs 60; nasal CPAP, 120 vs 25) than the study by He and associates,2 in which they demonstrated a significant decrease in survival in patients treated with UPPP.
Follow-up polysomnography may be important after UPPP to identify those patients who require additional treatment because of ongoing OSA due to an unsatisfactory response to UPPP. Snoring, which is the hallmark symptom of OSA, is usually relieved by UPPP, but silent severe apnea may persist. Thirty-three percent (3/9) of our patients and 30 percent (6/ 20) of the patients in the study by He and associates2 who did not have follow-up polysomnography died.