Effect of preoperative continuous positive airway pressure duration on outcomes after maxillofacial surgery for obstructive sleep apnoea.

Continuous positive airway pressure (CPAP) remains the first-line treatment for obstructive sleep apnoea (OSA), and is known to result in various physiological changes. The objective of this study was to evaluate the association between duration of preoperative CPAP therapy and outcome after maxillomandibular advancement (MMA) for OSA. We retrospectively analysed consecutive patients treated at our institution, and divided them into 2 groups based on duration of treatment with CPAP: short-term (up to 12 months) and long-term use (12 months or more). We controlled for baseline demographic and clinical characteristics. We compared postoperative scores for the apnoea/hypopnoea index (AHI) and the Epworth sleepiness scale (ESS), and lowest recorded oxygen saturation between groups. In 43 patients data were available on the preoperative use of CPAP, and in 37 of them preoperative and postoperative polysomnographic data were also available for inclusion. Most had bimaxillary advancement with genioplasty. Differences between the groups in mean reduction in the AHI and lowest oxygen saturation were not significant, and operative success rates were comparable. After operation, the reduction in ESS scores was significantly greater in the long-term group than in the short-term group (mean (SD) 8(3) compared with 2 (2), respectively, p<0.001). Our results suggest that the duration of use of CPAP preoperatively does not significantly influence objective outcome measures. The reduction in AHI scores after MMA was equivalent in both groups. The long-term group seemed to fare better than the short-term group on subjective outcome measures.