Bariatric surgery for treatment of sleep apnea syndrome in 15 morbidly obese patients: long-term results

Modified Uvulopalatopharyngoplasty with Tonsillectomy in Treatment of Obstructive Sleep Apnoea

Obstructive sleep apnoea is a common problem with many long-term consequences if left untreated. The purpose of this study is to find the efficacy of modified uvulopalatopharyngoplasty with tonsillectomy in the treatment of OSA symptoms, apnoea-hypopnoea index, Epworth sleepiness scale and its effect on blood pressure and cardiac status. Patients with obstructive sleep apnoea with apnoea-hypopnoea index more than 15 with tonsillar hypertrophy, Friedman stage < 3 and palatal collapse or obstruction at the level of velum as diagnosed by DISE were included in this prospective analytical cross-sectional study. Modified uvulopalatopharyngoplasty with tonsillectomy was done in all patients. History of nocturnal and daytime OSA symptoms, Epworth sleepiness scale, snoring score, polysomnogram, drug induced sleep endoscopy, blood pressure, echocardiogram to measure velocity across pulmonary and aortic valve and ECG were taken preoperatively and 6 months postoperatively. A total of 129 participants were recruited. 82 of the 129 patients (63.5%) were men; mean (SD) age was 44.2 (6.78) years. The patients were post operatively classified as responders and non-responders by the DISE finding. 107 patients (82.9%)-responders, had no narrowing and 22 patients (17.1%)-non-responders, had persistent narrowing of velum. Non-responders had increased baseline BMI when compared to responders. All the parameters were statistically improved in responders (p < 0.001). In non-responders, there was no statistical improvement in any of the parameters. Modified uvulopalatopharyngoplasty provides significant improvement in sleep parameters like AHI, Epworth sleepiness scale and other polysomnographic parameters. It significantly reduces the cardiac burden in OSA patients without any complications. Trial registration www.ctri.nic.in identifier: CTRI/2020/06/025759.

Does the "obesity paradox" exist after transcatheter aortic valve implantation?

Background

Transcatheter aortic valve implantation (TAVI) for symptomatic aortic stenosis is considered a minimally invasive procedure. Body mass index (BMI) has been rarely evaluated for pulmonary complications after TAVI. This study aimed to assess the influence of BMI on pulmonary complications and other related outcomes after TAVI.

Methods

The clinical data of 109 patients who underwent TAVI in our hospital from May 2018 to April 2021 were retrospectively analyzed. Patients were divided into three groups according to BMI: low weight (BMI < 21.9 kg/m², n = 27), middle weight (BMI 21.9–27.0 kg/m², n = 55), and high weight (BMI > 27.0 kg/m², n = 27); and two groups according to vascular access: through the femoral artery (TF-TAVI, n = 94) and through the transapical route (TA-TAVI, n = 15). Procedure endpoints, procedure success, and adverse outcomes were evaluated according to the Valve Academic Research Consortium (VARC)-2 definitions.

Results

High-weight patients had a higher proportion of older (p < 0.001) and previous percutaneous coronary interventions (p = 0.026), a higher percentage of diabetes mellitus (p = 0.026) and frailty (p = 0.032), and lower glomerular filtration rate (p = 0.024). Procedure success was similar among the three groups. The 30-day all-cause mortality of patients with low-, middle-, and high weights was 3.7% (1/27), 5.5% (3/55), and 3.7% (1/27), respectively. In the multivariable analysis, middle- and high-weight patients exhibited similar overall mortality (middle weight vs. low weight, p = 0.500; high weight vs. low weight, p = 0.738) and similar intubation time compared with low-weight patients (9.1 ± 7.3 h vs. 8.9 ± 6.0 h vs. 8.7 ± 4.2 h in high-, middle-, and low-weight patients, respectively, p = 0.872). Although high-weight patients had a lower PaO₂/FiO₂ ratio than low-weight patients at baseline, transitional extubation, and post extubation 12th hour (p = 0.038, 0.030, 0.043, respectively), there were no differences for post extubation 24th hour, post extubation 48th hour, and post extubation 72nd hour (p = 0.856, 0.896, 0.873, respectively). Chronic lung disease [odds ratio (OR) 8.038, p = 0.001] rather than high weight (OR 2.768, p = 0.235) or middle weight (OR 2.226, p = 0.157) affected postoperative PaO₂/FiO₂ after TAVI.

Conclusions

We did not find the existence of an obesity paradox after TAVI. BMI had no effect on postoperative intubation time. Patients with a higher BMI should be treated similarly without the need to deliberately extend the intubation time for TAVI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13019-022-01910-x.

Increased risk for the development of postoperative severe hypoxemia in obese women with acute type a aortic dissection

Background

The purpose of this study is to identify the risk factors for postoperative severe hypoxemia after surgery for acute type A aortic dissection.

Methods

This was a single-center retrospective study including 112 consecutive patients undergoing urgent aortic arch surgery for acute type A aortic dissection between December 2016 and April 2017 at Beijing Anzhen Hospital.

Results

Multivariate logistic regression analysis identified female (OR, 12.978; 95% CI, 3.332 to 50.546; p < 0.001) and increased body mass index (OR, 1.473; 95% CI, 1.213 to 1.789; p < 0.001) as independent predictors of postoperative severe hypoxemia in patients with acute type A aortic dissection.

Conclusions

Obesity and female were independent risk factors for postoperative severe hypoxemia in patients with acute type A aortic dissection. More attention should be paid to preventing postoperative severe hypoxemia in obese women with acute type A aortic dissection.

Sleepiness Score-Specific Outcomes of a Novel Tongue Repositioning Procedure for the Treatment of Continuous Positive Airway Pressure-Resistant Obstructive Sleep Apnea

Background:

The gold standard of treatment for obstructive sleep apnea (OSA) is continuous positive airway pressure (CPAP). However, more than a third of patients have such difficulty with its chronic use such that they seek other options or choose to remain untreated. We evaluated sleepiness score-specific outcomes and the use of CPAP after tongue repositioning surgery for the treatment of OSA.

Patients and Methods:

A self-administered questionnaire was completed pre- and postoperatively by 10 patients who underwent tongue repositioning surgery for the treatment of OSA from October 2010 to December 2012. The questionnaire included the Epworth Sleepiness Scale (ESS) for the assessment of daytime somnolence and questions regarding CPAP use and overall satisfaction.

Results:

Preoperatively, 6 patients were “very sleepy” (ESS ≥16), 4 patients were “sleepy” (ESS = 10–16), and 0 patients were “not sleepy” (ESS ≤10). 30 days postoperatively, sleepiness scores decreased (10 patients were “not sleepy” (ESS ≤10) with 0 patients “very sleepy” or “sleepy;” P = 0.002). Thus, the median ESS score for the “very sleepy” and “sleepy,” decreased from 20 to 4 and 13 to 5, respectively, and the “nonsleepy” group increased from 0 to 4. After a 180-day review, the improved ESS scores remained unchanged (the median for “very sleepy” decreased to 3.5 that for “sleepy” remained at 5, and the median for “not sleepy” decreased to 3.5). Surgery decreased CPAP use by 100%. The surgery was judged to be worthwhile by all 10 of patients using a questionnaire, and all 10 patients said that they would recommend the treatment to other patients with OSA.

Conclusions:

These preliminary data indicate that tongue-repositioning surgery for the treatment of OSA may be effective in improving excessive daytime sleepiness. These proof-of-concept data require confirmation in an appropriately powered controlled study.

A pilot study on the biomechanical assessment of obstructive sleep apnea pre and post bariatric surgery

Obesity is a major risk factor for obstructive sleep apnea patients. In obese patients the severity of this risk can be reduced by bariatric surgery. This pilot study investigates the perioperative effects of bariatric surgery on obstructive sleep apnea and on the physical and biomechanical characteristics of the upper airway. Polysomnography and computer tomography data for 10 morbid obese patients promoted for bariatric surgery were conducted before surgery and at 6 and 12 months postoperatively for assessment of the oropharyngeal anatomy, and subsequent three-dimensional modelling of the airway. Mean values for the apnea/hypopnea index and body mass index significantly reduced after surgery. To combine the effect of changes in the upper airway volume and body mass index, a new volume body mass index is introduced. This index increases with a successful bariatric surgery. Although bariatric surgery leads to an effective weight reduction for all age groups, for obstructive sleep apnea patients it may be effective for middle age, less effective for 50-60 years, and further less effective for patients over the age of 60 years.

Assessment of bariatric surgery efficacy on Obstructive Sleep Apnea (OSA)

A worldwide rise in weight and obesity is taking place, associated with an increase in several comorbid conditions, such as Obstructive Sleep Apnea (OSA). Bariatric surgery is an effective treatment approach for obesity, with resultant improvement in obesity-related comorbidities. However, the relationship between this type of treatment and OSA is not well established. This systematic review aims to assess and characterize the impact that different types of bariatric surgery have on obese OSA patients. 22 articles with stated preoperative apnea-hypopnea index (AHI), apnea index (AI) or respiratory disturbance index (RDI) were analyzed in this review. A significant improvement in AHI/AI/RDI occurred after surgery, in addition to the foreseeable reduction in body mass index (BMI). Moreover, almost every study stated a postoperative reduction of the AHI to < 20/h and/or a >50% postoperative reduction of AHI, with few exceptions. The interventions with a combined malabsorptive and restrictive mechanism, like roux-en-Y gastric bypass (RYGB), were more efficacious in resolving and improving OSA than purely restrictive ones, like laparoscopic adjustable gastric banding (LAGB). In conclusion, bariatric surgery has a significant effect on OSA, leading to its resolution or improvement, in the majority of cases, at least in the short/medium term (1-2 years). However, the different results must be interpreted with caution as there are many potential biases resulting from heterogeneous inclusion criteria, duration of follow-up, diagnostic methodology and assessed variables.

Bariatric Surgery or Non-Surgical Weight Loss for Obstructive Sleep Apnoea? A Systematic Review and Comparison of Meta-analyses

BACKGROUND

Obstructive sleep apnoea (OSA) is a well-recognised complication of obesity. Non-surgical weight loss (medical, behavioural and lifestyle interventions) may improve OSA outcomes, although long-term weight control remains challenging. Bariatric surgery offers a successful strategy for long-term weight loss and symptom resolution.

OBJECTIVES

To comparatively appraise bariatric surgery vs. non-surgical weight loss interventions in OSA treatment utilising body mass index (BMI) and apnoea-hypopnoea index (AHI) as objective measures of weight loss and apnoea severity.

METHODS

A systematic literature review revealed 19 surgical (n = 525) and 20 non-surgical (n = 825) studies reporting the primary endpoints of BMI and AHI before and after intervention. Data were meta-analysed using random effects modelling. Subgroup analysis, quality scoring and risk of bias were assessed.

RESULTS

Surgical patients had a mean pre-intervention BMI of 51.3 and achieved a significant 14 kg/m(2) weighted decrease in BMI (95%CI [11.91, 16.44]), with a 29/h weighted decrease in AHI (95%CI [22.41, 36.74]). Non-surgical patients had a mean pre-intervention BMI of 38.3 and achieved a significant weighted decrease in BMI of 3.1 kg/m(2) (95%CI [2.42, 3.79]), with a weighted decrease in AHI of 11/h (95%CI [7.81, 14.98]). Heterogeneity was high across all outcomes.

CONCLUSIONS

Both bariatric surgery and non-surgical weight loss may have significant beneficial effects on OSA through BMI and AHI reduction. However, bariatric surgery may offer markedly greater improvement in BMI and AHI than non-surgical alternatives. Future studies must address the lack of randomised controlled and comparative trials in order to confirm the exact relationship between metabolic surgery and non-surgical weight loss interventions in OSA resolution.

Impact of sleep-disordered breathing treatment on upper airway anatomy and physiology

Sleep-disordered breathing (SDB) is a major public health problem. Various anatomic, pathophysiologic, and environmental changes contribute to SDB. The successful treatment of SDB reverses many of these abnormal processes. The present article discusses the current clinical evidence that supports the reversibility and its potential application in the management of SDB. Continuous positive airway pressure reduces angiogenesis and inflammatory edema, increases pharyngeal size, and improves surrogate markers of vascular inflammation and tongue muscle fiber types. Mandibular advancement devices lead to favorable maxillary and mandibular changes, increase pharyngeal area, and improve hypertension. Uvulopalatopharyngoplasty increases posterior airway space and pharyngeal volume, reduces nasal and oral resistance, and lowers response to high CO2. Weight loss reduces nasopharyngeal collapsibility, critical closing pressure of the airway, apnea-hypopnea index, and improves oxygen saturations. Potential clinical benefits of these changes in the management of SDB and patient compliance with treatment are discussed.

The impact of bariatric surgery on obstructive sleep apnea: a systematic review

There is a strong relationship between obesity and the development of obstructive sleep apnea (OSA). Respectively, bariatric surgery is often touted as the most effective option for treating obesity and its comorbidities, including OSA. Nevertheless, there remains paucity of data in the literature of the comparison of all the specific types of bariatric surgery themselves. In an effort to answer this question, a systematic review was performed, to determine, of the available bariatric procedures [Roux-en-Y gastric bypass, laparoscopic sleeve gastrectomy, or biliopancreatic diversion (BPD)], which procedures were the most efficacious in the treatment of OSA. A total of 69 studies with 13,900 patients were included. All the procedures achieved profound effects on OSA, as over 75 % of patients saw at least an improvement in their sleep apnea. BPD was the most successful procedure in improving or resolving OSA, with laparoscopic adjustable gastric banding being the least. In conclusion, bariatric surgery is a definitive treatment for obstructive sleep apnea, regardless of the specific type.

Canadian Thoracic Society 2011 guideline update: diagnosis and treatment of sleep disordered breathing

The Canadian Thoracic Society (CTS) published an executive summary of guidelines for the diagnosis and treatment of sleep disordered breathing in 2006⁄2007. These guidelines were developed during several meetings by a group of experts with evidence grading based on committee consensus. These guidelines were well received and the majority of the recommendations remain unchanged. The CTS embarked on a more rigorous process for the 2011 guideline update, and addressed eight areas that were believed to be controversial or in which new data emerged. The CTS Sleep Disordered Breathing Committee posed specific questions for each area. The recommendations regarding maximum assessment wait times, portable monitoring, treatment of asymptomatic adult obstructive sleep apnea patients, treatment with conventional continuous positive airway pressure compared with automatic continuous positive airway pressure, and treatment of central sleep apnea syndrome in heart failure patients replace the recommendations in the 2006⁄2007 guidelines. The recommendations on bariatric surgery, complex sleep apnea and optimum positive airway pressure technologies are new topics, which were not covered in the 2006⁄2007 guidelines.

Sleep disorders in morbid obesity

The increasing prevalence of obesity has lead to an increase in the prevalence of sleep disordered breathing in the general population. The disproportionate structural characteristics of the pharyngeal airway and the diminished neural regulation of the pharyngeal dilating muscles during sleep predispose the obese patients to pharyngeal airway collapsibility. A subgroup of obese apneic patients is unable to compensate for the added load of obesity on the respiratory system, with resultant daytime hypercapnia. Weight loss using dietary modification and life style changes is the safest approach to reducing the severity of sleep apnea, but its efficacy is limited on the long run. Although it has inherent risks, bariatric surgery provides the most immediate result in alleviating sleep apnea. Obesity has been linked also to narcolepsy. The loss of neuropeptides co-localized in hypocretin neurons is suggested as the potential mechanism. Poor sleep quality, which leads to overall sleep loss and excessive daytime sleepiness has also become a frequent complaint in this population. Identifying abnormal nocturnal eating is critically important for patient care. Both sleep related eating disorder and night eating syndrome are treatable and represent potentially reversible forms of obesity.

Obesity hypoventilation syndrome

Obesity is becoming a major medical concern in several parts of the world, with huge economic impacts on health- care systems, resulting mainly from increased cardiovascular risks. At the same time, obesity leads to a number of sleep-disordered breathing patterns like obstructive sleep apnea and obesity hypoventilation syndrome (OHS), leading to increased morbidity and mortality with reduced quality of life. OHS is distinct from other sleep- related breathing disorders although overlap may exist. OHS patients may have obstructive sleep apnea/hypopnea with hypercapnia and sleep hypoventilation, or an isolated sleep hypoventilation. Despite its major impact on health, this disorder is under-recognized and under-diagnosed. Available management options include aggressive weight reduction, oxygen therapy and using positive airway pressure techniques. In this review, we will go over the epidemiology, pathophysiology, presentation and diagnosis and management of OHS.

Procedure and outcomes of Roux-en-Y gastric bypass

Bariatric surgery is an effective intervention for weight loss in the morbidly obese patient and can result in resolution of associated comorbidities. However, it is a complex area of practice and care, as these patients suffer a series of comorbidities that can compromise outcomes after surgery. Nurses must be aware of these comorbidities and anticipate the required interventions to ensure timely and effective treatment, and to minimize potential problems. This article reviews the technical procedures of the laparoscopic Roux-en-Y gastric bypass (LRYGBP)--which is considered the gold standard in bariatric surgery--and outlines its complications and outcomes. Other forms of bariatric surgery are briefly discussed in comparison to the LRYGBP. With knowledge in this area, nurses are in a ideal position to educate and prepare patients for life after surgery, and to diminish their anxiety during adaptation to this new phase of life.

[Guideline: Treatment of obstructive sleep apnea in adults]

The current guideline discusses conservative and surgical therapy of obstructive sleep apnea (OSA) in adults from the perspective of the ear, nose and throat specialist. The revised guideline was commissioned by the German Society of Ear-Nose-Throat, Head-Neck Surgery (DG HNO KHC) and compiled by the DG HNO KHC's Working Group on Sleep Medicine. The guideline was based on a formal consensus procedure according to the guidelines set out by the German Association of Scientific Medical Societies (AWMF) in the form of a"S2e guideline". Research of the literature available on the subject up to and including December 2008 forms the basis for the recommendations. Evaluation of the publications found was made according to the recommendations of the Oxford Centre for Evidence-Based Medicine (OCEBM). This yielded a recommendation grade, whereby grade A represents highly evidence-based studies and grade D those with a low evidence base.

Interactions between obesity and obstructive sleep apnea: implications for treatment

Obstructive sleep apnea (OSA) adversely affects multiple organs and systems, with particular relevance to cardiovascular disease. Several conditions associated with OSA, such as high BP, insulin resistance, systemic inflammation, visceral fat deposition, and dyslipidemia, are also present in other conditions closely related to OSA, such as obesity and reduced sleep duration. Weight loss has been accompanied by improvement in characteristics related not only to obesity but to OSA as well, suggesting that weight loss might be a cornerstone of the treatment of both conditions. This review seeks to explore recent developments in understanding the interactions between body weight and OSA. Weight loss helps reduce OSA severity and attenuates the cardiometabolic abnormalities common to both diseases. Nevertheless, weight loss has been hard to achieve and maintain using conservative strategies. Since bariatric surgery has emerged as an alternative treatment of severe or complicated obesity, impressive results have often been seen with respect to sleep apnea severity and cardiometabolic disturbances. However, OSA is a complex condition, and treatment cannot be limited to any single symptom or feature of the disease. Rather, a multidisciplinary and integrated strategy is required to achieve effective and long-lasting therapeutic success.

Effects of surgical weight loss on measures of obstructive sleep apnea: a meta-analysis

OBJECTIVE

Limited evidence suggests bariatric surgery can result in high cure rates for obstructive sleep apnea (OSA) in the morbidly obese. We performed a systematic review and meta-analysis to identify the effects of surgical weight loss on the apnea-hypopnea index.

METHODS

Relevant studies were identified by computerized searches of MEDLINE and EMBASE (from inception to March 17, 2008), and review of bibliographies of selected articles. Included studies reported results of polysomnographies performed before and at least 3 months after bariatric surgery. Data abstracted from each article included patient characteristics, sample size who underwent both preoperative and postoperative polysomnograms, types of bariatric surgery performed, results of preoperative and postoperative measures of OSA and body mass index, publication year, country of origin, trial perspective (prospective vs retrospective), and study quality.

RESULTS

Twelve studies representing 342 patients were identified. The pooled mean body mass index was reduced by 17.9 kg/m(2) (95% confidence interval [CI], 16.5-19.3) from 55.3 kg/m(2) (95% CI, 53.5-57.1) to 37.7 kg/m(2) (95% CI, 36.6-38.9). The random-effects pooled baseline apnea hypopnea index of 54.7 events/hour (95% CI, 49.0-60.3) was reduced by 38.2 events/hour (95% CI, 31.9-44.4) to a final value of 15.8 events/hour (95% CI, 12.6-19.0).

CONCLUSION

Bariatric surgery significantly reduces the apnea hypopnea index. However, the mean apnea hypopnea index after surgical weight loss was consistent with moderately severe OSA. Our data suggest that patients undergoing bariatric surgery should not expect a cure of OSA after surgical weight loss. These patients will likely need continued treatment for OSA to minimize its complications.

[Update on surgery for obstructive sleep apnea syndrome]

Several indications for surgery for obstructive sleep apnea (OSA) have been clarified within the past 3 years. In pediatric OSA, adenotonsillectomy and tonsillotomy are the most common treatments and are highly effective. In adults, nasal surgery facilitates--and sometimes enables--nasally applied continuous positive airway pressure (CPAP) treatment. Today, minimally invasive treatment options for mild OSA are established. Furthermore, several invasive surgical techniques have proven to be efficient in the treatment of mild to moderate OSA. Above an apnea-hypopnea index of 30, surgery should be done only as secondary treatment in cases of CPAP failure or noncompliance. Special forms of OSA, such as laryngeal OSA and supine OSA, must be kept in mind.

Obesity and obstructive sleep apnea: pathogenic mechanisms and therapeutic approaches

Obstructive sleep apnea is a common disorder whose prevalence is linked to an epidemic of obesity in Western society. Sleep apnea is due to recurrent episodes of upper airway obstruction during sleep that are caused by elevations in upper airway collapsibility during sleep. Collapsibility can be increased by underlying anatomic alterations and/or disturbances in upper airway neuromuscular control, both of which play key roles in the pathogenesis of obstructive sleep apnea. Obesity and particularly central adiposity are potent risk factors for sleep apnea. They can increase pharyngeal collapsibility through mechanical effects on pharyngeal soft tissues and lung volume, and through central nervous system-acting signaling proteins (adipokines) that may affect airway neuromuscular control. Specific molecular signaling pathways encode differences in the distribution and metabolic activity of adipose tissue. These differences can produce alterations in the mechanical and neural control of upper airway collapsibility, which determine sleep apnea susceptibility. Although weight loss reduces upper airway collapsibility during sleep, it is not known whether its effects are mediated primarily by improvement in upper airway mechanical properties or neuromuscular control. A variety of behavioral, pharmacologic, and surgical approaches to weight loss may be of benefit to patients with sleep apnea, through distinct effects on the mass and activity of regional adipose stores. Examining responses to specific weight loss strategies will provide critical insight into mechanisms linking obesity and sleep apnea, and will help to elucidate the humoral and molecular predictors of weight loss responses.

Improvement of associated respiratory problems in morbidly obese patients after open Roux-en-Y gastric bypass

BACKGROUND

Obstructive sleep apnea syndrome (OSAS) is present in 44% of patients scheduled for bariatric surgery. Respiratory dysfunction associated with this syndrome is attributable to chronic obstructive pulmonary disease (COPD) and/or obesity hypoventilation syndrome (OHS). We studied the long-term effect of bariatric surgery on weight loss, on the respiratory comorbidities associated with obesity, and on the need for non-invasive positive pressure ventilation.

METHODS

We followed a sample of patients with respiratory co-morbidity scheduled for open Capella Roux-en-Y gastric bypass (RYGBP) over 5-years. Patients who were positive for polysomnographic studies and required continous positive airway pressure (CPAP) before surgery were included. All patients were subjected to the same anesthetic and surgical protocols. At 1 year after surgery, polysomnographic studies were performed and arterial blood gases and pulmonary function were tested.

RESULTS

Of the 209 patients scheduled for bariatric surgery during the study period, 105 had respiratory co-morbidity. Of these, 30 required CPAP-BiPAP treatment before surgery and were included in our study. Surgery took 128 minutes (range 70 to 210 minutes). Tracheal extubation in the operating theater was possible for 26 patients (86.7%). During the early postoperative period, 7 patients (23.3%) presented respiratory complications. Length of hospitalization was 6.87 days (range 4 to 11 days). At 1 year after RYGBP, patients presented significant weight loss and improvement of hypoxemia (from 73.3 +/- 10.6 to 90.5 +/- 11.5, P = 0.000), hypercarbia (from 44.5 +/- 5.7 to 40.6 +/- 4.9, P = 0.005), and in spirometric (P = 0.004) and polysomnographic results (P = 0.001). CPAP-BiPAP treatment after weight loss was necessary in only 14% of patients (P = 0.001).

CONCLUSIONS

Weight loss after RYGBP improved arterial blood gases, respiratory tests and polysomnographic studies. CPAP treatment can be withdrawn in most patients.

Bariatric surgery in the treatment of obstructive sleep apnea in morbidly obese patients

BACKGROUND

Weight loss has been shown effective in the treatment of the obstructive sleep apnea-hypopnea syndrome. Regrettably, many obese patients are unable to achieve sustained and useful weight loss by dietary means. Recently, bariatric surgery has emerged as an alternative to treat obesity and many of its comorbidities, although its role for sleep apnea treatment is still not defined.

OBJECTIVES

To evaluate the impact of bariatric surgery on obstructive sleep apnea in morbidly obese patients.

METHODS

In this cohort study, polysomnography, Epworth Sleepiness Scale questionnaire and clinical assessment were performed in 12 of 13 morbidly obese patients with moderate to severe obstructive sleep apnea treated with bariatric surgery through Roux-en-Y gastric bypass procedure after a minimum of 18 months post surgery.

RESULTS

The mean (+/-SD) loss of excess body weight was 70.5 +/- 24%. The mean level obtained in the Epworth Scale was 4.8. There was a significant reduction in the apnea-hypopnea index, from a median of 46.5 (range: 33-140) to 16 (range: 0.9-87) events per hour (p < 0.05), an improvement in mean oxygen saturation from 85.7 +/- 5.1 to 94.5 +/- 3.6% (p < 0.05) and in minimum oxygen saturation from 64.7 +/- 13.4 to 78.7 +/- 13.7% (p < 0.05). The magnitude of the weight loss and the improvements in mean and minimum oxygen saturation were positively correlated, (r = 0.76; p <or= 0.05, and r = 0.59; p <or= 0.05, respectively).

CONCLUSIONS

Weight loss achieved by bariatric surgery is associated with significant long-term improvements in obstructive respiratory event, oxygenation and resolution of daytime somnolence.

Sleep apnea: clinical investigations in humans

Sleep apnea syndrome (SAS), a common disorder, is characterized by repetitive episodes of cessation of breathing during sleep, resulting in hypoxemia and sleep disruption. The consequences of the abnormal breathing during sleep include daytime sleepiness, neurocognitive dysfunction, development of cardiovascular disorders, metabolic dysfunction, and impaired quality of life. There are two types of SAS: obstructive sleep apnea syndrome (OSAS) and central sleep apnea syndrome (CSAS). OSAS is a prevalent disorder in which there is snoring, repetitive apneic episodes, and daytime sleepiness. Anatomical conditions causing upper airway obstruction (obesity or craniofacial abnormalities such as retrognathia or micrognathia) can cause OSAS. CSAS, much less common than OSAS, is a disorder characterized by cessation of breathing which is caused by reduced respiratory drive from the central nervous system to the muscles of respiration. The latter condition is common in patients with heart failure and cerebral neurologic diseases. The diagnosis of SAS requires assessment of subjective symptoms and apneic episodes during sleep documented by polysomnography. Treatments of OSAS include continuous positive airway pressure (CPAP), oral appliances, and surgery; patients with CSAS are treated with oxygen, adaptive servo-ventilation, or CPAP. With assessment and treatment of the SAS, patients usually have resolution of their disabling symptoms, subsequently resulting in improved quality of life.

Pulmonary considerations in obesity and the bariatric surgical patient

Severe obesity can be associated with significant alterations in normal cardiopulmonary physiology. The pathophysiologic effects of obesity on a patient's pulmonary function are multiple and complex. The impact of obesity on morbidity and mortality are often underestimated. Bariatric surgery has been shown to be the most effective modality of reliable and durable treatment for severe obesity. Surgical weight loss improves and, in most cases, completely resolves the pulmonary health problems associated with obesity.

Obesity and obstructive sleep apnea-hypopnea syndrome: the impact of bariatric surgery

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is characterized by successive episodes of cessation or decrease in respiratory airflow, in which obesity is an important risk factor. The prevalence of the disease in morbidly obese patients is approximately 70%. Treatment is based on the use of continuous positive airway pressure (CPAP) and weight loss in obese patients. Weight loss by dieting often produces unsatisfactory results, and the use of CPAP does not show good adherence because of being long-term and uncomfortable. Bariatric surgery has emerged as the treatment for morbid obesity and various associated co-morbidities. This article reviews the principal studies that evaluate the modifications in obstructive sleep apnea after bariatric surgery, showing that surgery is an effective treatment for the management of OSAHS in morbidly obese patients.

Objective evidence that bariatric surgery improves obesity-related obstructive sleep apnea

BACKGROUND

Obstructive sleep apnea (OSA) is associated with obesity. Our aim in this study is to report objective improvement of obesity-related OSA and sleep quality after bariatric surgery.

METHODS

Prospective bariatric patients were referred for polysomnography if they scored >or=6 on the Epworth Sleepiness Scale. The severity of OSA was categorized by the respiratory disturbance index (RDI) as follows: absent, 0 to 5; mild, 6 to 20; moderate, 21 to 40; and severe, <40. Patients were referred for repeat polysomnography 6 to 12 months after bariatric surgery or when weight loss exceeded 75 lbs. Means were compared using paired t tests. Chi-square tests and linear regression models were used to assess associations between clinical parameters and RDI; P<.05 was considered statistically significant.

RESULTS

Of 349 patients referred for polysomnography, 289 patients had severe (33%), moderate (18%), and mild (32%) OSA; 17% had no OSA. At a median of 11 months (6 to 42 months) after bariatric surgery, mean body mass index (BMI) was 38 +/- 1 kg/m2 (P<.01 vs 56 +/- 1 kg/m2 preoperatively) and the mean RDI decreased to 15 +/- 2 (P<.01 vs 51 +/- 4 preoperatively) in 101 patients who underwent postoperative polysomnography. In addition, minimum oxygen saturation, sleep efficiency, and rapid eye movement latency improved, and the requirement for continuous positive airway pressure was reduced (P<or=.025). Male gender and increasing BMI correlated with increasing RDI (P<.01) by chi-square analysis. In a multivariate linear regression model adjusted for age and gender, preoperative BMI correlated with preoperative RDI (r=0.27; P<.01).

CONCLUSIONS

OSA is prevalent in at least 45% of bariatric surgery patients. Preoperative BMI correlates with the severity of OSA. Surgically induced weight loss significantly improves obesity-related OSA and parameters of sleep quality.

Effect of bariatric surgery on obstructive sleep apnoea in adolescents

Obese adolescents, particularly those with extreme obesity (body mass index > or =40 kg/m(2)), are developing serious medical complications at an unexpectedly high rate. As non-operative approaches to weight loss have shown less than optimal results, paediatric patients are increasingly seeking bariatric surgical intervention. Bariatric surgical procedures are designed to restrict stomach size or impair macronutrient absorption. They typically result in substantial weight loss. As with adult studies, paediatric studies generally report good obstructive sleep apnoea (OSA)-related outcomes after bariatric surgery. Therefore, in patients meeting eligibility criteria, bariatric surgery can be a valuable approach for achieving significant weight loss and resolution of serious comorbidities such as OSA. Studies that focus on long-term assessment of OSA are needed to understand whether OSA resolution after adolescent bariatric surgery is sustainable over the lifetime.

Obese obstructive sleep apnea patients with tonsil hypertrophy submitted to tonsillectomy

The physiopathology of obstructive sleep apnea-hypopnea syndrome (OSAHS) is multifactorial and obesity has been shown to be one of the main factors correlated with its occurrence. In obese patients with anatomical alterations of the upper airways it is often difficult to predict success for surgical correction since obesity is a limiting factor. Therefore, the aim of the present study was to evaluate the results of tonsillectomy in a specific group of patients, i.e., obese OSAHS patients with tonsil hypertrophy. Seven OSAHS patients with moderate obesity with obstructive palatine tonsil hypertrophy were submitted to tonsillectomy. All patients were submitted to pre- and postoperative appraisal of body mass index, otorhinolaryngology examination and polysomnography. Patients' average age was 36.4 +/- 10.3 years and average preoperative body mass index was 36.6 +/- 6.3 kg/m(2). Postoperative weight did not differ significantly from preoperative weight (P = 0.27). Average preoperative apnea and hypopnea index (AHI) was 81 +/- 26/h and postoperative AHI was 23 +/- 18/h (P = 0.0005). Average preoperative minimum oxyhemoglobin saturation (SaO2 min) was 69 +/- 14% and the postoperative value was 83 +/- 3% (P = 0.038). In relation to AHI, 6 (86%) of the 7 patients studied showed a reduction of 50% in relation to preoperative level and of these, 4 (57%) presented AHI of less than 20%. Only one patient presented a reduction of less than 50% in AHI, but even so showed improved SaO2 min. Tonsillectomy treatment for OSAHS in obese patients with obstructive palatine tonsil hypertrophy caused a significant reduction in AHI, with improvement in SaO2 min. This procedure could be eventually considered as an option of treatment for obese OSAHS patients with significant tonsil hypertrophy when continuous positive air pressure therapy is not possible as the first choice of treatment.

Neurologic complications after surgery for obesity

Bariatric surgical procedures are increasingly common. In this review, we characterize the neurologic complications of such procedures, including their mechanisms, frequency, and prognosis. Literature review yielded 50 case reports of 96 patients with neurologic symptoms after bariatric procedures. The most common presentations were peripheral neuropathy in 60 (62%) and encephalopathy in 30 (31%). Among the 60 patients with peripheral neuropathy, 40 (67%) had a polyneuropathy and 18 (30%) had mononeuropathies, which included 17 (94%) with meralgia paresthetica and 1 with foot drop. Neurologic emergencies including Wernicke's encephalopathy, rhabdomyolysis, and Guillain-Barré syndrome were also reported. In 18 surgical series reported between 1976 and 2004, 133 of 9996 patients (1.3%) were recognized to have neurologic complications (range: 0.08-16%). The only prospective study reported a neurologic complication rate of 4.6%, and a controlled retrospective study identified 16% of patients with peripheral neuropathy. There is evidence to suggest a role for inflammation or an immunologic mechanism in neuropathy after gastric bypass. Micronutrient deficiencies following gastric bypass were evaluated in 957 patients in 8 reports. A total of 236 (25%) had vitamin B(12) deficiency and 11 (1%) had thiamine deficiency. Routine monitoring of micronutrient levels and prompt recognition of neurological complications can reduce morbidity associated with these procedures.

Polysomnography before and after weight loss in obese patients with severe sleep apnea

OBJECTIVE

While obstructive sleep apnea (OSA) is strongly related to obesity, few studies have examined polysomnographic (PSG) changes with major weight loss. We examined the effect of weight loss following laparoscopic adjustable gastric banding (LAGB) on the PSG changes in patients with severe OSA. In addition, we studied daytime sleepiness, the metabolic syndrome and quality of life (QOL).

METHODS

A prospective study was conducted of 25 severely obese patients (17 men, eight women) with paired diagnostic PSG, biochemical and questionnaire studies, the first prior to LAGB and the second at least 1 y later. Subjects with a baseline apnea-hypopnea index (AHI) >25/h were included.

RESULTS

Subject baseline age was 44.7 y, weight 154 kg and body mass index 52.7 kg/m(2). The second PSG study was conducted 17.7+/-10 (range 12-42) months after surgery and mean percentage of excess loss and weight loss were 50.1+/-15% (range 24-80%) and 44.9+/-22 kg (range 18-103 kg), respectively. There was a significant fall in AHI from 61.6+/-34 to 13.4+/-13, improved sleep architecture with increased REM and stage III and IV sleep, daytime sleepiness, as measured by Epworth Sleepiness Scale, of 13+/-7.0 to 3.8+/-3.0, and fewer patients requiring nasal continuous positive airways pressure (CPAP). There were also major improvements in the metabolic syndrome, QOL, body image and fewer symptoms of depression (P<0.05 for all).

CONCLUSION

Weight loss provides major improvement or resolution of OSA and CPAP requirements. It also reduces daytime sleepiness, and improves the metabolic syndrome and QOL. LAGB placement should be considered a broadly effective therapy for sleep apnea in the severely obese patient.

Obstructive sleep apnea

BACKGROUND

Patients with undiagnosed obstructive sleep apnea (OSA) represent a major public health problem, and studies suggest that the incidence of OSA may be even higher than estimated.

TYPES OF STUDIES REVIEWED

The authors reviewed current literature describing comorbidities of patients with OSA.

RESULTS

Sleep medicine is a relatively new field. Dental practitioners may lack educational exposure and, as a result, feel uncomfortable asking their patients sleep-related questions. While patients with well-controlled OSA present few difficulties for routine dental treatment, it is imperative that health care professionals understand the comorbidities associated with OSA and that untreated OSA may contribute to increased morbidity and mortality.

CLINICAL IMPLICATIONS

Dental professionals have a unique doctor-patient relationship that affords them a role in recognizing sleep disorders by exploring the history of patients who are sleepy.

Obstructive Sleep Apnea-Hypopnea Syndrome

OSAHS should be an expected condition in many patients encountered by primary care providers. The diagnosis may arise because of patient daytime dysfunction, partner prompting, or in the course of managing comorbidities adversely influenced by the hemodynamic, neural, humoral,and inflammatory consequences of repetitive desaturations and arousals.OSAHS should be suspected in patients who exhibit habitually loud snoring, witnessed apneas/choking/gasping during sleep, hypertension, neck circumferences of 17 inches or greater, obesity, and laterally narrowed oropharynxes. Diagnosis is established by polysomnography. CPAP is the treatment of choice for most patients. Education, follow-up, and heated humidification may help bolster compliance. Lifestyle modifications, oral appliances, and upper surgeries are additional treatment options.

Surgical options for obesity

Several bariatric procedures are available that have excellent long-term weight loss results and are backed by several large clinical trials. Purely restrictive procedures like VBG have fallen out of favor because of inadequate long-term weight loss. Gastric bypass and the BPD are well-studied and show significant resolution of obesity-related comorbidities. Long-term nutritional consequences are seen more commonly after malabsorptive procedures like the BPD than after hybrid malabsorptive-restrictive procedures like the gastric bypass. Because compliance and long-term nutritional follow-up are mandatory after any bariatric procedure, purely malabsorptive procedures should be reserved for super obese patients who are at risk for inadequate long-term weight loss. Furthermore, minimally invasive techniques have evolved and essentially have eliminated the high incidence of postoperative wound complications and incisional hernias frequently seen after open gastric bypass. Until the development ofa similarly successful procedure, gastric bypass will continue to be the gold standard bariatric procedure with its concurrent sustained weight loss benefits and resolution of comorbidities.

Metabolic and cardiovascular improvements after biliopancreatic diversion in a severely obese patient

BACKGROUND

Severe obesity is associated with important morbidity and increased mortality. The successes of lifestyle modifications and drug therapy have been partial and mostly unsustained in reducing obesity and its comorbidities. Bariatric surgery, particularly biliopancreatic diversion with duodenal switch reduces efficiently excess body weight and improves metabolic and cardiovascular functions.

CASE PRESENTATION

A 56-year-old man with severe clinical obesity underwent a biliopancreatic diversion with a duodenal switch after unsuccessful treatment with weight loss pharmacotherapy. He had diabetes, hypertension and sleep apnea syndrome and was on three medications for hypertension and two hypoglycemic agents in addition to > 200 insulin units daily. Eleven months after the surgery, he had lost 40% of his body weight. The lipid profile showed great improvement and the hypertension and diabetes were more easily controlled with no more insulin needed. The pseudonormalized pattern of left ventricular diastolic function improved and ventricular walls showed decreased thickness.

CONCLUSION

Biliopancreatic diversion may bring metabolic and cardiovascular benefits in severely obese patients from a cardiovascular perspective.

Sleep. 1: Obstructive sleep apnoea/hypopnoea syndrome: definitions, epidemiology, and natural history

Arguments over the definition of obstructive sleep apnoea/hypopnoea syndrome (OSAHS) have still not been satisfactorily resolved. As a result, robust estimates of the prevalence of OSAHS are not possible. New approaches are needed to identify those who have "CPAP responsive" disease, enabling more accurate estimates to be made of the prevalence of the sleep apnoea syndrome in the community.

Evidence-based medicine in sleep apnea surgery

Since the first description of sleep apnea as a clinical entity, the understanding of it within the medical community has increased significantly. Much research has explored the causes, assessment, and treatment of this disease. This research has resulted in a variety of tools for assessment and approaches to treatment. As research progresses, new data have shed light on the strengths of traditional approaches and their limitations. This article gives background for current approaches and charts a potential future course for sleep apnea assessment and treatment.

Behavioral and pharmacologic therapy of obstructive sleep apnea

Previous attempts at using pharmacologic agents in the treatment of OSA have been disappointing. Medroxyprogesterone has not been found to be useful in the treatment of OSA. Use of protriptyline is limited by frequent side effects, but its role in mild and REM-related OSA must be clarified. SSRIs seem to be ineffective in treatment of severe OSA. Further studies are needed to determine their effect in persons with mild disease. This is important because patients with mild OSA (AHI < 15 hours) are most likely to be noncompliant with CPAP therapy [91]. A recent systematic review of drug treatments for OSA concluded that the current data do not support the use of any drug as an alternative to CPAP [92]. Of 56 studies identified, only 9 studies met methodologic criteria. Clearly, basic research and adequately powered clinical trials are needed to identify an effective medication for OSA.

Obstructive sleep apnoea

Obstructive sleep apnoea is a disease of increasing importance because of its neurocognitive and cardiovascular sequelae. Abnormalities in the anatomy of the pharynx, the physiology of the upper airway muscle dilator, and the stability of ventilatory control are important causes of repetitive pharyngeal collapse during sleep. Obstructive sleep apnoea can be diagnosed on the basis of characteristic history (snoring, daytime sleepiness) and physical examination (increased neck circumference), but overnight polysomnography is needed to confirm presence of the disorder. Repetitive pharyngeal collapse causes recurrent arousals from sleep, leading to sleepiness and increased risk of motor vehicle and occupational accidents. The surges in hypoxaemia, hypercapnia, and catecholamine associated with this disorder have now been implicated in development of hypertension, but the association between obstructive sleep apnoea and myocardial infarction, stroke, and congestive heart failure is not proven. Continuous positive airway pressure, the treatment of choice for obstructive sleep apnoea, reduces sleepiness and improves hypertension.