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Article #73

SUMMARY

The author points to the problem of many--he estimates 60%-- patients with Obstructive Sleep Apnea (OSA) not accepting or using consistently Continuous Positive Airway Pressure (CPAP) treatment. He suggests two areas of technical advances that may alleviate this problem: (1) improvements in CPAP to make this more acceptable, and (2) new techniques to make surgery an effective alternative. In the first category, he refers to at least eight different self-adjusting CPAP (Automatic CPAP or Auto-CPAP)to allow continuous, individualized adjustment of CPAP pressure throughout nights of laboratory study for diagnosis and pressure titration, or even throughout the entire course of treatment at home. The underlying concept is that an individual's pressure needs may vary over the course of time, whether a single night or many years. Such automatic pressure adjustments may then assure that the pressure used at any given time is just enough to control OSA and no more than necessary. Otherwise, pressures set on only one occasion may later prove excessive, inadequate, or at different times both. The author focuses on the advantage of using the lowest pressure that will work, in order to minimize side-effects. Some studies show that Automatic CPAP does result in lower overall pressures. It is unclear whether this has resulted in less side-effects or better acceptance by patients. No obvious differences in effect have yet emerged between different systems. Drawbacks to Auto-CPAP include its greater expense (about $500 more) than conventional CPAP, and the reluctance of many third-party payors to authorize payment. If the Auto-CPAP is used to conduct initial home testing and pressure titration without a technician present, this may result in significant and even dangerous errors. For example, mask leaks if uncorrected may lead to excessive pressures. The author then proceeds to innovations in surgical treatment of OSA. Reduction of the soft palate, uvulopalatopharyngoplasty (UPPP), once done routinely with a scalpel, now may be performed in new ways that allow local anesthesia and outpatient surgery. These include laser-assisted uvulopalatoplasty (LAUP), cautery-assisted palatal stiffening operation (CAPSO), and radiofrequency energy (Somnoplasty). However, all appear to share the drawback of insufficient therapeutic effects on OSA, as measured by reduction of the Apnea Hypopnea Index (AHI), one common criterion for success being a 50% reduction in AHI. This often modest reduction in OSA (still not enough to yield a normal AHI in many cases) may benefit only one-third or less of patients undergoing this type of surgery, generally considered a poor result. Little detail is available about research results with CAPSO, but it may cause considerable postoperative pain. Somnoplasty causes less pain, but may require repeating the procedure, incurring increased cost. Since the overriding disadvantage of palatal surgery to date is insufficient effectiveness, more extensive surgical procedures have been developed, specifically directed towards reducing obstruction at the base of the tongue, an area not benefited by palatal procedures. Drs. Robert Riley and Nelson Powell at Stanford University Medical Center pioneered (1981) a stepwise approach. When UPPP had failed, they proceeded to genioglossus advancement (pulling forward the muscle under the tongue) with hyoid suspension (lifting the hyoid bone in the neck for similar effect). If this failed, they went on to maxillomandibular advancement (cutting facial bones in order to move them forward and, with them, the tongue). The reviewer criticizes their largest, retrospective study (1993) of 415 patients, on the basis of a large proportion (26%) of patients lost to follow-up. However, smaller, prospective studies support the better effects of their more advanced procedures, unfortunately unavailable from surgeons at most facilities. Other surgical approaches which may lessen obstruction at the tongue base include the Repose and Somnoplasty procedures. The Repose procedure, involving insertion of a screw in the lower jaw with a suture connecting it to the tongue, requires general anesthesia, and has shown mostly poor results as to both effectiveness and side-effects. In contrast, Somnoplasty is done on an outpatient basis with local anesthesia. Still, it has had unimpressive benefits, some serious side-effects, and the additional drawback of cost. So far, these procedures remain to proven advantageous. In passing, the author mentions Implanted Electrical Nerve Stimulation as an alternative yet to be adequately assessed.

COMMENTS

Overall, this review leaves me without much sense of newer technological advances having yielded better alternatives for patients. This may be just a matter of needing further research, as with the Auto-CPAP, which sounds like a promising improvement, at least in theory, if not adequately proven in clinical trials. As for newer surgical approaches, I agree with the author's favorable assessment of Drs. Riley and Powell's stepwise approach to surgical treatment failures. In fact, I have enough regard for their published results to have journeyed across the country to have them perform what I still call their second-stage procedure (genioglossus advancement with hyoid suspension), performed on me, alas without benefit. Even with Federal Blue Cross Blue Shield, the amount it cost me was considerable, and so was my postoperative pain. Other surgical treatments, especially the commonly used UPPP, do not seem worth the considerable postoperative pain and even the minimal risk of undergoing general anesthesia.

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