Short-term results of upper airway stimulation in obstructive sleep apnoea patients: the Amsterdam experience.

OBJECTIVES: This paper aimed to: retrospectively analyse single-centre results in terms of surgical success, respiratory outcomes and adverse events after short-term follow up in obstructive sleep apnoea patients treated with upper airway stimulation; and evaluate the correlation between pre-operative drug-induced sleep endoscopy findings and surgical success. METHODS: A retrospective descriptive cohort study was conducted, including a consecutive series of obstructive sleep apnoea patients undergoing implantation of an upper airway stimulation system. RESULTS: Forty-four patients were included. The total median Apnoea-Hypopnea Index and oxygen desaturation index significantly decreased from 37.6 to 8.3 events per hour (p < 0.001) and from 37.1 to 15.9 events per hour (p < 0.001), respectively. The surgical success rate was 88.6 per cent, and did not significantly differ between patients with or without complete collapse at the retropalatal level (p = 0.784). The most common therapy-related adverse event reported was (temporary) stimulation-related discomfort. CONCLUSION: Upper airway stimulation is an effective and safe treatment in obstructive sleep apnoea patients with continuous positive airway pressure intolerance or failure. There was no significant difference in surgical outcome between patients with tongue base collapse with or without complete anteroposterior collapse at the level of the palate.

Floppy epiglottis during drug-induced sleep endoscopy: an almost complete resolution by adopting the lateral posture.

PURPOSE: To analyze the presence of a floppy epiglottis (FE) during drug-induced sleep endoscopy in non-apneic snoring patients, non-positional obstructive sleep apnea (OSA) patients (NPP), and position-dependent OSA patients (PP) and to evaluate the impact of maneuvers and body position during drug-induced sleep endoscopy, including jaw thrust and supine and lateral head (and trunk) position. METHODS: Retrospective cohort study. RESULTS: In total, 324 patients were included. In 60 patients (18.5%), a FE was found in supine position: seven non-apneic snoring patients and 53 OSA patients. When performing lateral head rotation only, a FE was present in four patients (NPP, N = 0; PP, N = 4). When patients were tilted to both lateral head and trunk position, a FE was found in only one subject. After applying jaw thrust, a FE was still present in 10 patients. The prevalence of a FE did not differ between NPP and PP. When comparing baseline characteristics between patients with and without a FE in supine position, no significant differences were found. CONCLUSION: A FE appears almost exclusively in supine position. In patients with a FE, positional therapy can be a promising alternative as a standalone treatment, but also as part of combination therapy with for example mandibular advancement devices or less invasive forms of upper airway surgery.

Positional therapy in patients with residual positional obstructive sleep apnea after upper airway surgery.

PURPOSE/BACKGROUND: A considerable portion of patients has residual positional obstructive sleep apnea (POSA) after upper airway surgery. Those patients could benefit from additional treatment with positional therapy (PT). The objective of this prospective study was to assess the additional effect of PT in patients with residual POSA after upper airway surgery for sleep apnea. METHODS: A polysomnography (PSG) was used to diagnose a patient with residual POSA after surgery. After informed consent, patients were treated with PT for 3 months and underwent a follow-up PSG while using the sleep position trainer (SPT). Changes in apnea-hypopnea index (AHI) and sleep position parameters were analyzed. Compliance rates and mean disease alleviation (MDA) were determined. RESULTS: Thirty-three patients with a median postoperative AHI of 18.3/h sleep were included. With the SPT median AHI dropped to 12.5/h sleep and the Epworth Sleepiness Scale (ESS) improved from 10.0 to 7.0. After 3 months, 37.5 % patients were considered responders of whom 31.3 % had treatment success. The compliance rate with SPT was 89.0 %. MDA was 44.7 % for SPT alone. With the combination of both surgery and SPT, MDA was 65.6 %. CONCLUSIONS: The results of this study indicate that additional PT in a complex OSA patient population with residual POSA after surgery can increase overall therapeutic effectiveness by improving the median MDA from 39.5 % (effect of surgery alone) to 65.6 % (effect of combining surgery and PT).

Positional OSA part 2: retrospective cohort analysis with a new classification system (APOC).

BACKGROUND: In Part 1 of this two-part article, the Amsterdam Positional Obstructive Sleep Apnoea Classification (APOC) was recently introduced, a classification system aimed at facilitating the identification of suitable candidates for positional therapy (PT): patients who will benefit from a clinically significant improvement of their obstructive sleep apnoea (OSA) with PT. APOC was developed with new generation PT devices in mind rather than conventional PT (tennis ball technique). New generation PT can be defined as a well-tolerated device which prevents a patient from adopting the worst sleeping position (WSP) without negatively influencing sleep efficiency, as objectified by a full night polysomnography (PSG). PT is rapidly gaining momentum in the scope of OSA treatment. The objective of this manuscript is to measure the prevalence of position-dependent obstructive sleep apnoea (POSA) according to the APOC, in a consecutive series of patients referred for PSG as well as an investigation of associations between POSA and certain patient characteristics. METHODS: We performed a retrospective, single-centre cohort study including a consecutive series of patients who underwent a PSG during the period of April 2010 until October 2010. RESULTS: Within this OSA-cohort (n = 253), a prevalence of POSA of 69 % when applying APOC is measured, compared to 64 % when applying Cartwright's classification. An inverse relation between POSA and BMI was observed, likewise between POSA and apnoea hypopnoea index (AHI). CONCLUSION: We are of opinion that APOC is a suitable tool to identify patients who will or will not benefit from PT, thus resulting in more cost-efficient treatment.

Positional OSA part 1: Towards a clinical classification system for position-dependent obstructive sleep apnoea.

BACKGROUND: In 1984, Cartwright suggested that physicians should differentiate between patients with either positional obstructive sleep apnoea (POSA) or non-positional OSA. Treatment of POSA has advanced dramatically recently with the introduction of a new generation of positional therapy (PT), a small device attached to either the neck or chest which corrects the patient from adopting the supine position through a vibrating stimulus. Encouraging data have been published suggesting that this simple therapy successfully prevents patients with POSA from adopting the supine position without negatively influencing sleep efficiency, as well as allowing for good adherence. Unfortunately, evaluating the efficacy of PT and comparing results are hindered by the fact that there are no universally used POSA criteria. In 1984, Cartwright introduced the arbitrary cut-off point of a difference of 50% or more in apnoea index between supine and non-supine positions. INTRODUCTION: The aim of this project was to introduce a new classification system, which ideally should identify suitable candidates for PT: patients that will benefit from a clinically significant improvement of their OSA with PT. The shared use of this classification can facilitate collection of data across multiple centres and comparison of results across studies. We report on the development and process that resulted in the Amsterdam Positional OSA Classification (APOC). METHOD: A panel of three field experts were instructed to independently assign the diagnosis POSA to 100 randomly selected patients they considered likely to benefit from a clinically significant improvement of their OSA with PT. In a group setting, the completed lists were compared. Discrepancies were discussed until consensus was met. This resulted in the consensus standard used to calibrate the new classification. Using the nominal group technique, the APOC was developed. RESULTS: The APOC criteria evolve around the percentage of total sleep time spent in either the worst sleeping position (WSP) or the best sleeping position (BSP) and the apnoea-hypopnoea index (AHI) in BSP. On applying APOC, one discriminates between the true positional patient, the non-positional patient and the multifactorial patient, whose OSA severity is influenced in part by sleep position. APOC has an increased sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) compared to previously applied POSA criteria in identifying patients that will benefit from positional therapy.

Evaluation of position dependency in non-apneic snorers.

The aims of this study are to determine the prevalence of position dependency in non-apneic snorers, as defined by the American Academy of Sleep Medicine (AASM) guidelines, and to investigate the influence of various factors such as BMI, neck circumference, age, gender, and sleep efficiency on sleeping position. A cohort of consecutive patients was screened for complaints of excessive snoring or symptoms suspicious for sleep disordered breathing. Overnight polysomnographic data were collected and non-apneic snorers who met all the inclusion criteria were selected for statistical analysis. To assess position-dependent snoring, the snore index (total snores/h) was used. Supine-dependent patients were defined as having a supine snore index higher than their total non-supine snore index. 76 patients were eligible for statistical analysis. Prevalence of position dependency in non-apneic snorers was 65.8% (p < 0.008). A stepwise regression showed that only BMI had a significant effect (p < 0.003) on the supine snore index. This is the first study that uses the AASM guidelines to accurately define non-apneic snorers (AHI < 5) and provides scientific evidence that the majority of non-apneic snorers are supine dependent. Furthermore, these results show that non-apneic snorers with a higher BMI snore more frequently in supine position. The use of sleep position therapy therefore, has the potential to play a significant role in improving snoring and its associated physical and psychosocial health outcomes in this population.

Theoretical approach towards increasing effectiveness of palatal surgery in obstructive sleep apnea: role for concomitant positional therapy?

PURPOSE: The aims of this study are to evaluate the effect of palatal surgery (uvulopalatopharyngoplasty (UPPP) or Z-palatoplasty (ZPP)) with or without (+/-) concomitant radiofrequent ablation of the base of the tongue (RFTB) on body position-specific apnea-hypopnea index (AHI) values in patients with obstructive sleep apnea (OSA) and to compare this treatment outcome to the theoretical effect of (addition of) positional therapy (PT). METHODS: Retrospective analysis of pre- and posttreatment polysomnographies in 139 patients who had undergone UPPP/ZPP +/- RFTB was performed. Hypothetical evaluation of the effects of (addition of) ideal PT on AHI in positional OSA (POSA) patients was carried out. RESULTS: Median AHI significantly decreased from 18.0 to 11.2 (p < 0.001). Median AHI in all separate positions decreased significantly as well. Sixty-eight patients suffered from POSA and showed a significant decrease in median AHI from 15.5 to 11.5 (p = 0.002). In the 71 non-positional OSA (NPOSA) patients, the significant AHI decrease was more outspoken, from 23.0 to 11.0 (p < 0.001). Our hypothetical model to treat POSA patients with an ideal PT (as monotherapy or in addition to surgery) resulted in a significant median AHI decrease from 18.0 to 4.5 (p < 0.0001). CONCLUSIONS: UPPP/ZPP +/- RFTB significantly reduces AHI and all body position-specific AHI values. This reduction is significantly higher in NPOSA than in POSA patients. When considering UPPP/ZPP +/- RFTB, the effect of body position needs to be taken into account. PT, either as monotherapy or in addition to surgery, theoretically has shown to improve treatment results dramatically in POSA patients. Prospective, controlled trials focusing on the effects of this combination of treatments should further evaluate this hypothetical conclusion.

The undervalued potential of positional therapy in position-dependent snoring and obstructive sleep apnea-a review of the literature.

PURPOSE: Research during the past 10-20 years shows that positional therapy (PT) has a significant influence on the apnea-hypopnea index. These studies are predominantly performed as case series on a comparably small number of patients. Still, results have not found their way into the daily diagnostic and treatment routine. An average of 56 % of patients with obstructive sleep apnea (OSA) have position-dependent OSA (POSA), commonly defined as a difference of 50 % or more in apnea index between supine and non-supine positions. A great deal could be gained in treating patients with POSA with PT. The aim of this paper was to perform a thorough review of the literature on positional sleep apnea and its therapy. METHODS: A broad search strategy was run electronically in the MEDLINE and EMBASE databases using synonyms for position and sleep apnea. RESULTS: Sixteen studies were found which examined the effect of PT on OSA. In this literature review, we discuss the various techniques, results, and compliance rates. CONCLUSION: Long-term compliance for PT remains an issue, and although remarkable results have been shown using innovative treatment concepts for PT, there is room for both technical improvement of the devices and for further research.

Exploration of the relationship between sleep position and isolated tongue base or multilevel surgery in obstructive sleep apnea.

This study aimed to elucidate the role of sleep position as a confounding factor on apnea hypopnea index (AHI) and surgical success in isolated tongue base or multilevel surgery. This study was conducted using retrospective analysis of patients who underwent hyoid suspension because of obstructive sleep apnea (OSA), in the St. Lucas Andreas Hospital, Amsterdam, The Netherlands, from 2004 to 2011. Concurrent surgical treatment was documented. Sleep positions and corresponding AHIs before and after surgery were compared. A total of 130 patients were included. 94 patients underwent surgery of base of tongue and palate (either uvulopalatopharyngoplasty or Z-palatoplasty), of whom 72 underwent concurrent radiofrequent thermotherapy of the base of tongue. 36 patients underwent base of tongue surgery alone, of whom 22 underwent concurrent radiofrequent thermotherapy of the base of tongue. 65 patients either had a successful reduction in AHI or in AI. Isolated tongue base or multilevel surgery was as successful on the supine AHI as it was on the AHI in other sleeping positions. Surgery was not more successful in the group with position-dependent patients as compared with the non-position-dependent patients (P = 0.615). Successful and non-successful surgical results could not be explained by variations in percentages of supine sleep position. Sleep position is not a confounding factor on surgical outcomes in tongue base surgery. The results of isolated base of tongue or multilevel surgery in position-dependent OSA patients leave room for improvement, possibly through positional therapy.

Obstructive sleep apnea is underrecognized and underdiagnosed in patients undergoing bariatric surgery.

The aim of this study was to evaluate prevalence of obstructive sleep apnea among patients undergoing bariatric surgery and the predictive value of various clinical parameters: body mass index (BMI), neck circumference (NC) and the Epworth Sleepiness Scale (ESS). We performed a prospective, multidisciplinary, single-center observational study including all patients on the waiting list for bariatric surgery between June 2009 and June 2010, irrespective of history or clinical findings. Patients visited our ENT outpatient clinic for patient history, ENT and general examination and underwent a full night polysomnography, unless performed previously. As much as 69.9% of the patients fulfilled the criteria for OSA (mean BMI 44.2 ± SD 6.4 kg/m(2)); 40.4% of the patients met the criteria for severe OSA. The regression models found BMI to be the best clinical predictor, while the ROC curve found the NC to be the most accurate predictor of the presence of OSA. The discrepancy of the results and the poor statistical power suggest that all three clinical parameters are inadequate predictors of OSA. In conclusion, in this large patient series, 69.9% of patients undergoing BS meet the criteria for OSA. More than 40% of these patients have severe OSA. A mere 13.3% of the patients were diagnosed with OSA before being placed on the waiting list for BS. On statistical analysis, increased neck circumference, BMI and the ESS were found to be insufficient predictors of the presence of OSA. Polysomnography is an essential component of the preoperative workup of patients undergoing BS. When OSA is found, specific perioperative measures are indicated.