Expansion Sphincter Pharyngoplasty: An Investigation into Outcomes and Patient Characteristics Impacting Success

Introduction: Expansion sphincter pharyngoplasty (ESP) is a procedure intended to treat obstructive sleep apnea (OSA) in patients with pharyngeal wall-predominant collapse and continuous positive airway pressure (CPAP) intolerance. There still exist gaps in understanding of patient characteristics that may predict favorable outcomes.

Methods: Patients with a diagnosis of OSA who underwent ESP since 2013 were identified by review surgical schedule. Patients with mild OSA or inaccessible pre- and post-operative polysomnogram data were excluded. Patient demographics, objective and subjective sleep data were analyzed.

Results: Thirty-four of 68 (50%) identified patients met inclusion criteria. Mean pre-operative apnea-hypopnea index (AHI) was 45.1±22.9 and oxygen desaturation index (ODI) was 41.6±22.4; post-operative AHI and ODI were 30.0±21.6 and 27.4±19.9, respectively. Of these patients, 10 (29%) achieved at least 50% AHI reduction and 15 (44%) achieved at least 25% ODI reduction. Eight patients (24%) met modified Sher criteria. All 34 patients had a pre-operative oxygen nadir less than 90%; 23 (68%) experienced some improvement post-operatively, but only 3 (13%) achieved a nadir of at least 90%. Multivariate regression controlling for age, sex, body mass index, neck circumference, Mallampati score, and tonsil size did not demonstrate statistically significant improvement in AHI, ODI, oxygen nadir, apnea index, nor hypopnea index. Seven (24%) patients went on to receive hypoglossal nerve stimulator implantation.

Conclusions: ESP is a surgical option to treat CPAP-refractory patients with oropharyngeal collapse, but it is not always effective alone. This study is a preliminary analysis of our larger cohort – additional external records are expected to be collected on excluded patients.