Results of sleep apnea surgery
At CSSC, we assess patients before and after surgery with a 1) sleep study, 2) endoscopic gardening of the airway 3) symptomatic score called ESS.
Thus far, we have analysed 40 patients' results pre and postoperatively. When assessed by a sleep study, success is defined as a fifty per cent reduction in apnoea events and lowering the AHI number below 20 events an hour. If using the above definition, CSSC has achieved over 80% success rate for some of the most challenging anatomy noted in published literature (Freedman III type anatomy-large tongues and small tonsils).
However, when endoscopically graded and symptomatically assessed, all the patients have had a positive outcome. Over 90% of the operated patients managed to avoid the need for a machine after surgery. This is despite not meeting the criteria for success, defined by a sleep study score. We observed that the apnoea score alone is insufficient to define true success.
We noted some of those who felt better and avoided a CPAP machine did not always show a correlating reduction in apnoea events in their sleep study. The lack of correlation was due to various reasons. At times, they tended to sleep more on their backs (where apnoeas are worse) after surgery, as they felt their airway was more open. Further, some slept more in REM or DREAM sleep after surgery, where sleep apnoea occurs the most. In one patient, baseline oxygen level improved so much (to 97%) that even their lowest dip to 91% was considered a hypopnea event in their sleep study. Before surgery, their oxygen was consistently lower but had lesser recorded dips. There were two other patients who failed to show any improvement in their sleep score, despite clinical improvement. Both of them will be trialling a 3D printed mouthguard as an adjunct treatment. They were unable to tolerate a CPAP machine preoperatively but are likely to succeed with combination therapy.
Over 85% of the patients coming to CSSC successfully solved their sleep apnoea with Sleep Apnea Surgery, CPAP or combination therapy. 15% were either lost to follow up or unwilling to use recommended treatment.
Traditionally difficult-Freedman III stage is no longer is a barrier for sleep apnoea surgery. However, not every single patient have had a suitable solution. We are working on a new index to predict outcomes better. The above data was presented at the Australian Conference (ASOHNS) in 2020 and will be presented at 2021 ASOHNS followed by the publication of our data.