[Preoperative overnight airway pressure measurement for predicting the outcome of revised uvulopalatopharyngoplasty].

ABSTRACT

OBJECTIVE: The distribution of upper airway obstruction sites can be identified quantitatively and dynamically with continuous airway pressure measurements in obstructive sleep apnea hypopnea syndrome ( OSAHS) patients. Its value as a clinical predictor for the outcome of revised uvulopalatopharyngoplasty was evaluated. METHODS: The upper airway obstruction sites (transpalatal level, tongue base or hypolarynx level) were determined preoperatively with overnight upper airway pressure monitoring and concurrent polysomnography (PSG). Of one's total amount of obstructive events, the proportion of apnea/hypopnea events located at Transpalatal level was quantified as contribution of transpalatal obstruction. Of all OSAHS patients, 26 males and 1 female underwent revised uvulopalatopharyngoplasty (2 had same stage transpalatal advancement pharyngoplasty) and had follow-up PSG 6. 33 +/- 0.84 months after surgery. The relationship of transpalatal obstruction proportion, age, tonsil size and body mass index (BMI) and the reduction in apnoea hypopnea index (AHI) was analyzed. RESULTS: The AHI (times/hr) of 27 subjects decreased from 63.9 +/- 20.7 to 28.4 +/- 25.4. The response rate was 51.9% (defined as AHI reduction over 50%). Correlation between the transpalatal obstruction proportion and the AHI reduction percentage was significant (r = 0.609), so was the degree of the tonsil size (r = 0.511). The proportion of tongue base level obstruction showed a negative correlation for the AHI reduction. Patients with oropharynx obstruction percentage > or = 70% had a success rate of 90% and all patients with oropharynx obstruction percentage <60% responded poorly to the operation. The regression model showed distribution of obstructive sites, along with tonsil size and other PSG parameters could predict 66.7% of the postoperative AHI of transpalatal level surgery (F = 6.701, P = 0.001) . CONCLUSIONS: Contribution of transpalatal level obstruction has significant predictive value to the outcome of transpalatal level surgery in OSAHS patients.