OSA treatment history in an upper airway stimulation trial cohort

Objectives

Analyze the obstructive sleep apnea (OSA) treatment history in a group of participants who enrolled in a hypoglossal nerve stimulation trial.

Methods

Moderate-severe OSA patients with difficulty adhering to CPAP presented for enrollment in a multicenter trial. Self-reported history on prior OSA medical therapy was collected at enrollment, including OSA diagnosis date, CPAP start and stop dates, oral appliance trial, and reasons for discontinuation or non-adherence.

Results

The cohort consisted of 929 participants, 83% male, with a mean age (53.9 ± 10.5) years. Ninety percent (n = 835) had complete CPAP information including 47% (n = 435) who discontinued therapy prior to enrollment and 43% (n = 400) who were still attempting CPAP but had inadequate adherence. Abandonment rates were 60% at 1-year, 73% at 3-years, and 86% at 5-years. Oral appliance therapy was attempted by 171 patients for mean (1.8 ± 2.3) years, with 81% abandonment at 1 year, 89% at 3-years, and 94% at 5-years.

Conclusions

In this CPAP-refractory cohort, high rates of CPAP abandonment were reported in the first several years with approximately half of the participants not receiving any treatment despite being diagnosed for >5 years. Close clinical follow-up and consideration of alternative treatment options is indicated in all OSA patients in order to ensure adequate longitudinal care.

Upper-airway stimulation for obstructive sleep apnea

BACKGROUND

Obstructive sleep apnea is associated with considerable health risks. Although continuous positive airway pressure (CPAP) can mitigate these risks, effectiveness can be reduced by inadequate adherence to treatment. We evaluated the clinical safety and effectiveness of upper-airway stimulation at 12 months for the treatment of moderate-to-severe obstructive sleep apnea.

METHODS

Using a multicenter, prospective, single-group, cohort design, we surgically implanted an upper-airway stimulation device in patients with obstructive sleep apnea who had difficulty either accepting or adhering to CPAP therapy. The primary outcome measures were the apnea-hypopnea index (AHI; the number of apnea or hypopnea events per hour, with a score of ≥15 indicating moderate-to-severe apnea) and the oxygen desaturation index (ODI; the number of times per hour of sleep that the blood oxygen level drops by ≥4 percentage points from baseline). Secondary outcome measures were the Epworth Sleepiness Scale, the Functional Outcomes of Sleep Questionnaire (FOSQ), and the percentage of sleep time with the oxygen saturation less than 90%. Consecutive participants with a response were included in a randomized, controlled therapy-withdrawal trial.

RESULTS

The study included 126 participants; 83% were men. The mean age was 54.5 years, and the mean body-mass index (the weight in kilograms divided by the square of the height in meters) was 28.4. The median AHI score at 12 months decreased 68%, from 29.3 events per hour to 9.0 events per hour (P<0.001); the ODI score decreased 70%, from 25.4 events per hour to 7.4 events per hour (P<0.001). Secondary outcome measures showed a reduction in the effects of sleep apnea and improved quality of life. In the randomized phase, the mean AHI score did not differ significantly from the 12-month score in the nonrandomized phase among the 23 participants in the therapy-maintenance group (8.9 and 7.2 events per hour, respectively); the AHI score was significantly higher (indicating more severe apnea) among the 23 participants in the therapy-withdrawal group (25.8 vs. 7.6 events per hour, P<0.001). The ODI results followed a similar pattern. The rate of procedure-related serious adverse events was less than 2%.

CONCLUSIONS

In this uncontrolled cohort study, upper-airway stimulation led to significant improvements in objective and subjective measurements of the severity of obstructive sleep apnea. (Funded by Inspire Medical Systems; STAR ClinicalTrials.gov number, NCT01161420.).

Safety and Effectiveness of Upper Airway Stimulation via the Hypoglossal Nerve for Obstructive Sleep Apnea

Objectives:

Determine safety and effectiveness of upper airway stimulation for treatment of obstructive sleep apnea (OSA) in a prospective, multi-center trial; with subsequent randomized, controlled therapy withdrawal evaluation.

Methods:

This study enrolled and screened 900 adult subjects. Inclusion criteria were moderate-to-severe OSA (apnea-hypopnea index [AHI] 20-50), prior continuous positive airway pressure (CPAP) failure or intolerance, and body mass index (BMI) < 32. All qualified subjects underwent further screening with drug-induced sleep endoscopy (DISE) to exclude those with concentric palatal collapse. 126 subjects meeting all inclusion/exclusion criteria then underwent surgical implantation of a right sided unilateral hypoglossal nerve stimulation electrode, with pulse generator and respiration sensor (Upper Airway Stimulation System, Inspire Medical Systems, Minnesota). Patients were evaluated at 2, 6, and 12 months. Primary outcome measures included AHI, oxygen desaturation index, Epworth Sleepiness Scale, and Functional Outcomes of Sleep Questionnaire at 12 months. Therapy withdrawal effect was evaluated by randomizing a subset of consecutive responders to one week of on or off therapy for controlled comparison.

Results:

All 126 subjects were successfully implanted. In general, subjects were middle aged (mean 54.5 ± 10.2 yrs), male (83%), with severe OSA (mean baseline AHI 32.0 ± 11.8). Transient dysarthria and dysphagia were noted in a minority of patients. Over 70% of subjects have completed the study, with the remaining scheduled to complete 12 month evaluation by April, 2013. Final safety and effectiveness outcomes will be presented.

Conclusions:

Implantation of an upper airway stimulation system involving unilateral hypoglossal nerve electrode placement appears safe and feasible, with transient dysarthria occurring infrequently. Effectiveness will be addressed after completion of 12 month follow-up for all subjects.

Long-term effect of acoustic trauma on distortion product otoacoustic emissions in chickens

Distortion product otoacoustic emissions (DPOAE), 2F1-F2, were measured in chickens before and after exposure to a 1.5-kHz pure tone presented at 120-dB sound-pressure level for 48 h. The low-level component of the DPOAE input/output function was shifted to the right at all frequencies immediately after the exposure with the greatest effect occurring at and above the exposure frequency. The slope of the high-level component of the input/output also increased significantly for test frequencies close to and above the exposure frequency so that the amplitude of the DPOAE was equal to or greater than normal at high stimulus levels. DPOAE obtained at the highest and lowest frequencies were almost normal after 8 weeks of recovery; however, the input/output functions near the exposure frequency showed almost no improvement over the 8-week recovery period. The lack of recovery could conceivably be due to residual damage to hair cells that survived the exposure or to incomplete regeneration of the tectorial membrane.

Surgical advances in treating otitis media

Surgical methods of treating otitis media and its sequelae are discussed, according to the classification of otitis media presented in an earlier report. Surgical management of otitis media with effusion and recurrent purulent otitis media includes myringotomy and use of ventilation tubes. Occasionally, otitis media with effusion will lead to structural and other pathologic changes in the middle ear, and conservative treatments such as use of medication or tubes will not suffice. Indications and methods for exploratory tympanotomy and reconstruction of the middle ear are discussed. In such instances, tympanoplasty can be used to the patient's benefit. Chronic otitis media with mastoiditis, defined by the presence of intractable pathologic tissue, generally requires surgical correction. Classic methods include simple mastoidectomy, modified radical (Bondy) mastoidectomy, and radical mastoidectomy. Current classifications of procedures would also include closed-cavity tympanomastoidectomy, open-cavity tympanomastoidectomy, and intact-bridge tympanomastoidectomy (a combined approach). The diagnostic and surgical approach to silent or subclinical otitis media is discussed. Diagnosis and treatment of sequelae of otitis media, including sequelae in the middle ear and, less commonly, in the inner ear, are discussed.

The true cost of protective loop colostomy

Transverse loop colostomies are commonly used to "protect" low colorectal anastomoses after anterior resection for rectal carcinoma. However, anastomotic leaks occur despite proximal decompression. We studied 61 consecutive patients who underwent anterior resection to evaluate the cost of loop colostomy as reflected by morbidity, mortality, and length of post-operative hospital stay. Colostomy patients had significantly greater blood loss (736 vs. 500 ml, p = 0.004), more blood transfusions (1.55 units vs. 0.41 units, p less than 0.001), and longer operations (238 vs. 193 min, p = 0.005). They were also older (68 vs. 65, p = 0.13), had lesions closer to the anal verge (10.2 vs. 11.4 cm, p = 0.07), and had more infectious complications (13.6% vs. 2.6%, 0.05 less than p less than 0.1) than patients without colostomies. Colostomy was not related to sex or stage. There were no anastomotic leaks among those with colostomies and only one among those without colostomies; there were no associated mortalities. Patients with colostomies stayed an additional 10 days, on average, when readmitted for colostomy closure. The 22 patients who received loop colostomies had postoperative stays averaging one-third longer than patients without colostomies (16 vs. 12 days, p = 0.004). In both groups, the 8th postoperative day was the mean for resumption of a regular diet; all patients were eating a regular diet by the 12th postoperative day. The delay in discharging colostomy patients was due to the additional time necessary for patients to learn to change their appliance and irrigate their stoma. Proximal diverting colostomies may more than double the total dollar cost of anterior resection, although DRG reimbursement is the same with or without a colostomy. This additional cost could be reduced by initiating ostomy teaching in the preoperative period and by reducing the use of unnecessary colostomies.