Psychological and behavioral evaluation

The psychological evaluation and preparation is extremely important. A significant proportion of morbidly obese patients have known or undiagnosed psychological illness, such as depression, anxiety, binge eating, or posttraumatic stress disorder. Around half of bariatric patients take psychotropic drugs. Therefore, a thorough evaluation is very important. The social history, life stressors, dietary and weight loss history, and eating disorders of the patient should be evaluated. This screening is very important for long-term success. Most centers look for stability of these conditions and do not attempt to prohibit intervention. Relative contraindications vary from institution to institution but may include smoking, significant alcohol intake, and other substance abuse. Other concerns that may lead to poor long-term success include being consistently abusive to staff, missing multiple appointments, being in an excessive rush to undergo surgery, and significantly gaining weight while in the evaluation process. The relatively long evaluation process of several months with repeated contact with several health care providers helps to tease out some of these issues.

Dietary counseling is initiated preoperatively, is emphasized throughout the preoperative evaluation process, and should be reinforced postoperatively. Dietary indiscretions can lead to persistent postoperative problems such as nausea and pain. The maladaptive eating that may result from these operations may lead to failure of adequate weight loss, overall discontent, and even weight recidivism.

There are not much data to support a preoperative weight loss regimen; however, many believe that losing weight may be very beneficial. We routinely ask all our patients, especially those with a BMI more than 50 to lose 5% to 10% of their excess weight. Losing weight is done with the help of nutritionists and medical bariatricians. Patients may be placed on a modified protein-sparing diet to preserve their protein stores. The weight loss helps decrease visceral fat, making it technically easier to manipulate and retract the liver and small bowel mesentery. This technical ease is especially helpful in the laparoscopic approach and may help reduce complications. Another added benefit is that the patient undergoes a trial of behavior modification and is prepared for the immediate postoperative dietary change. Having bariatric surgery requires a lifelong change in eating habits. Success at a preoperative weight loss regimen may predict who will have a better postoperative weight loss and helps improve patient understanding.

Medical evaluation

A comprehensive and thorough medical evaluation is done for perioperative risk stratification and the diagnosis and optimization of comorbid illness. After a thorough history taking and physical examination, routine laboratory work and studies are obtained in all patients as listed in Table 1 .

There are few medical contraindications to bariatric surgery. More serious or absolute contraindications include incurable cancer, Crohn disease, and severe comorbid conditions that significantly increase perioperative risk such as active angina or decompensated heart failure. AIDS and cirrhosis are generally considered contraindications, but there are reports of safely performing bariatric surgery in human immunodeficiency virus–infected patients who do not have full-blown AIDS and are well controlled with the antiretrovirals. Patients with mild cirrhosis without significant portal hypertension can undergo bariatric surgery, but operative plans may have to be altered, with sleeve gastrectomy being a potential option because both gastric bypass and gastric band surgery require dissection near the esophagogastric junction with the potential for significant bleeding. An overall poor quality of life with limited life expectancy and minimal chance of improvement with surgery are also a contraindication.

Cardiac assessment should be performed according to the American Heart Association guidelines, last published in 2007 with a focused update in 2009. These latest guidelines indicate that very few patients require preoperative cardiac testing, such as those with unstable coronary syndromes, decompensated heart failure, severe valvular disease, or atrial or ventricular arrhythmias. This is because recent evidence shows that perioperative revascularization is not helpful and may be more harmful for most patients with asymptomatic disease.

There are difficulties, however, in assessing bariatric patients. To use reliable clinical predictors and consider the patients to be asymptomatic, the patients have to be able to perform activities that require at least 4 metabolic equivalents. These activities include doing housework, climbing a flight of stairs, or walking up a hill. Many bariatric patients are unable to do this because of multiple factors, including osteoarthritis, lower extremity edema and wounds, prolonged immobility, or real cardiopulmonary disease. These factors make the assessment of bariatric patients difficult. Moreover, the actual cardiac testing modalities also can be limited because exercise stress testing may not be possible because of the factors already mentioned. The accuracy of nuclear testing, such as thallium scanning, can be diminished in patients with a BMI less than 30. Transthoracic echocardiography can reveal poor images. Some investigators believe that transesophageal dobutamine stress echocardiography may be more reliable than other tests, but it is more invasive and expensive. The other important factor that is tied in with pulmonary testing and can increase perioperative risk is significant pulmonary hypertension caused by chronic obesity–related hypoventilation and sleep apnea. It is important to screen for this hypertension as well. Because of these difficulties, there is a low threshold to screen asymptomatic patients who have intermediate cardiac risk factors or a combination of risks such as prior myocardial infarction or known coronary artery disease (CAD), compensated congestive heart failure, renal insufficiency, advanced age and diabetes, smoking, and/or a strong family history of CAD.

The prevalence of obstructive sleep apnea (OSA) is 39% to 71% in bariatric patients. Many patients are unaware that they have OSA until they come for a bariatric evaluation. Initial screening is done with a history taking and physical examination and a daytime sleepiness evaluation, such as the Epworth sleepiness scale, but most patients are referred for a polysomnography or sleep study. Up to 82% of those who are referred for a sleep study are diagnosed with sleep apnea. It is important to initiate continuous positive airway pressure (CPAP) or bilevel positive airway pressure (BiPAP) before surgery to ensure a good fitting mask and patient compliance. Use of CPAP or BiPAP perioperatively, such as in the recovery room after surgery, and during sleep periods, day or night, postoperatively is very important to reduce hypoxemia, hypercarbia, and significant pulmonary vasoconstriction. The use of these devices are extremely important in patients with preexisting pulmonary hypertension because these patients can have respiratory failure, acute right heart failure, and cardiovascular collapse due to hypoventilation.

Limited data exist for the recommendation of routine screening for Helicobacter pylori in bariatric patients. The rate of H pylori positivity in bariatric patients is similar to that in the normal population and varies from 10% to 37.5%. H pylori infection was not necessarily associated with symptomatic patients. The importance of this finding lies in the fact that some retrospective studies have shown a positive correlation between H pylori infection and the rate of postoperative marginal ulceration after Roux-en-Y gastric bypass (RYGB). However, with other methods of testing for H pylori infection (serum titer, breath test), endoscopy may not be required to check for positivity.

Medical evaluation

A comprehensive and thorough medical evaluation is done for perioperative risk stratification and the diagnosis and optimization of comorbid illness. After a thorough history taking and physical examination, routine laboratory work and studies are obtained in all patients as listed in Table 1 .

There are few medical contraindications to bariatric surgery. More serious or absolute contraindications include incurable cancer, Crohn disease, and severe comorbid conditions that significantly increase perioperative risk such as active angina or decompensated heart failure. AIDS and cirrhosis are generally considered contraindications, but there are reports of safely performing bariatric surgery in human immunodeficiency virus–infected patients who do not have full-blown AIDS and are well controlled with the antiretrovirals. Patients with mild cirrhosis without significant portal hypertension can undergo bariatric surgery, but operative plans may have to be altered, with sleeve gastrectomy being a potential option because both gastric bypass and gastric band surgery require dissection near the esophagogastric junction with the potential for significant bleeding. An overall poor quality of life with limited life expectancy and minimal chance of improvement with surgery are also a contraindication.

Cardiac assessment should be performed according to the American Heart Association guidelines, last published in 2007 with a focused update in 2009. These latest guidelines indicate that very few patients require preoperative cardiac testing, such as those with unstable coronary syndromes, decompensated heart failure, severe valvular disease, or atrial or ventricular arrhythmias. This is because recent evidence shows that perioperative revascularization is not helpful and may be more harmful for most patients with asymptomatic disease.

There are difficulties, however, in assessing bariatric patients. To use reliable clinical predictors and consider the patients to be asymptomatic, the patients have to be able to perform activities that require at least 4 metabolic equivalents. These activities include doing housework, climbing a flight of stairs, or walking up a hill. Many bariatric patients are unable to do this because of multiple factors, including osteoarthritis, lower extremity edema and wounds, prolonged immobility, or real cardiopulmonary disease. These factors make the assessment of bariatric patients difficult. Moreover, the actual cardiac testing modalities also can be limited because exercise stress testing may not be possible because of the factors already mentioned. The accuracy of nuclear testing, such as thallium scanning, can be diminished in patients with a BMI less than 30. Transthoracic echocardiography can reveal poor images. Some investigators believe that transesophageal dobutamine stress echocardiography may be more reliable than other tests, but it is more invasive and expensive. The other important factor that is tied in with pulmonary testing and can increase perioperative risk is significant pulmonary hypertension caused by chronic obesity–related hypoventilation and sleep apnea. It is important to screen for this hypertension as well. Because of these difficulties, there is a low threshold to screen asymptomatic patients who have intermediate cardiac risk factors or a combination of risks such as prior myocardial infarction or known coronary artery disease (CAD), compensated congestive heart failure, renal insufficiency, advanced age and diabetes, smoking, and/or a strong family history of CAD.

The prevalence of obstructive sleep apnea (OSA) is 39% to 71% in bariatric patients. Many patients are unaware that they have OSA until they come for a bariatric evaluation. Initial screening is done with a history taking and physical examination and a daytime sleepiness evaluation, such as the Epworth sleepiness scale, but most patients are referred for a polysomnography or sleep study. Up to 82% of those who are referred for a sleep study are diagnosed with sleep apnea. It is important to initiate continuous positive airway pressure (CPAP) or bilevel positive airway pressure (BiPAP) before surgery to ensure a good fitting mask and patient compliance. Use of CPAP or BiPAP perioperatively, such as in the recovery room after surgery, and during sleep periods, day or night, postoperatively is very important to reduce hypoxemia, hypercarbia, and significant pulmonary vasoconstriction. The use of these devices are extremely important in patients with preexisting pulmonary hypertension because these patients can have respiratory failure, acute right heart failure, and cardiovascular collapse due to hypoventilation.

Limited data exist for the recommendation of routine screening for Helicobacter pylori in bariatric patients. The rate of H pylori positivity in bariatric patients is similar to that in the normal population and varies from 10% to 37.5%. H pylori infection was not necessarily associated with symptomatic patients. The importance of this finding lies in the fact that some retrospective studies have shown a positive correlation between H pylori infection and the rate of postoperative marginal ulceration after Roux-en-Y gastric bypass (RYGB). However, with other methods of testing for H pylori infection (serum titer, breath test), endoscopy may not be required to check for positivity.