Last updated: 11/24/2009

Diagnosis

DETERMINATION OF OBESITY. The diagnosis of a patient for bariatric surgery begins with measuring the degree of the patient's obesity. This measurement is crucial because the NIH and almost all health...

insurers have established specific limits for approval of bariatric procedures.

The obesity guidelines that are cited most often were drawn up by Milliman and Robertson, a nationally recognized company that establishes medical need for a wide variety of procedures for health insurers. The Milliman and Robertson criteria for a patient to qualify for weight loss surgery are as follows:

• be least 100 lb (45 kg) over ideal weight, as defined by life insurance tables; have a BMI of 40 or higher; or have a BMI over 35 with a coexisting serious medical condition (for example: severe diabetes or coronary artery disease)
• demonstrate failure to lose or regain of weight despite having tried a multidisciplinary weight control program
• have another cause of obesity, such as an endocrine disorder
• have attained full adult growth

The patient must be treated not only by a doctor with special training in obesity surgery, but in a comprehensive program that includes preoperative psychological screening and medical examination; nutritional counseling; exercise counseling; and participation in support groups

There are several ways to measure obesity. Some are based on the relationship between a person's height and weight. The older measurements of this correlation are the so-called "height-weight" tables that listed desirable weights for a given height. The limitation of height-weight tables is that they do not distinguish between weight of human fatty tissue and weight of lean muscle tissue—many professional athletes and body builders are overweight by the standards of these tables. A more accurate measurement of obesity is body mass index, or BMI. The BMI is an indirect measurement of the amount of body fat. The BMI is calculated in English measurements by multiplying a person's weight in pounds by 703.1, then dividing that number by the person's height in inches squared. A BMI between 19 and 24 is considered normal; 25–29 is overweight; 30–34 is moderately obese; 35–39 is severely obese; and 40 or higher is defined as morbidly obese.

More direct methods of measuring body fat include measuring the thickness of the skinfold at the back of the upper arm, and bioelectrical impedance analysis (BIA). Bioelectrical impedance measures the total amount of water in the body, using a special instrument that calculates the different degrees of resistance to a mild electrical current in different types of body tissue. Fatty tissue has a higher resistance to the current than body tissues containing larger amounts of water. A higher percentage of body water indicates a greater amount of lean tissue.

PSYCHOLOGICAL EVALUATION. Psychiatric and psychological screening before a VBG is done to evaluate the patient's emotional stability and to ensure the expectations of the results of weight loss are not unrealistic. Because of social prejudice against obesity, some obese people who have felt isolated from others or suffered job discrimination come to think of weight loss surgery as a magical or quick solution to all the problems in their lives. In addition, the surgeon will want to make sure that the patient understands the long-term lifestyle adjustments that are necessary after surgery, and that the patient is committed to making those changes. A third reason for a psychological assessment before a VBG is to determine whether the patient's eating habits are compulsive; these would be characterized by the persistent and irresistible impulse to eat with unknown or unconscious purpose. Compulsive eating is not a reason for not having weight loss surgery, but it does mean that the psychological factors contributing to the patient's obesity will also require treatment.

OTHER TESTS AND EXAMINATIONS. Patients must have a complete physical examination and blood tests before being considered for a VBG. Some bariatric surgeons will not accept patients with histories of major psychiatric illness; alcohol or drug abuse; previous abdominal surgery; or collagen vascular diseases, which include systemic lupus erythematosus (SLE) and rheumatoid arthritis. Many will not accept patients younger than 16 or older than 55, although some surgeons report successful VBGs in patients over 70. In any event, the patient will need to provide documentation of physical condition, particularly comorbid diseases or disorders, to their insurance company.

Preparation

Preparation for bariatric surgery requires more attention to certain matters than most other forms of surgery requiring hospitalization.

HEALTH INSURANCE ISSUES. Both bariatric surgeons and people who have had weight loss surgery report that obtaining preauthorization for a VBG from insurance companies is a lengthy, complicated, and frequently frustrating process. Insurance companies tend to reflect the prejudices against obese people that exist in the wider society. Although this situation is slowly changing because of increasingly widespread recognition of the high costs of obesity-related diseases, people considering a VBG should start early to secure approval for their operation. The American Obesity Association (AOA) has a pamphlet entitled, Weight Management and Health Insurance, a useful guide to the process of getting coverage for weight loss surgery. The pamphlet is available for free download from the AOA Web site.

LIFESTYLE CHANGES. A VBG requires a period of recovery at home after discharge from the hospital. Since the patient's physical mobility will be limited, the following should be done before the operation:

• Arrange for leave from work, assistance at home, help with driving, and similar tasks and commitments.
• Obtain a handicapped parking permit.
• Check the house or apartment thoroughly for needed adjustments to furniture, appliances, lighting, and personal conveniences; specific recommendations include the purchase of a shower chair and toilet seat lift. People recovering from bariatric surgery must minimize bending, stooping, and any risk of falling. There are good guides available written by people who have had weight loss surgery that describe household safety and comfort considerations in further detail.
• Stock up on prescription medications, nonperishable groceries, cleaning supplies, and similar items to minimize shopping. Food items should include plenty of clear liquids (juices, broth, soups) and soft foods (oat-meal and other cooked cereals, gelatin dessert mixes).
• Have a supply of easy-care clothing with elastic waistbands and simple fasteners. Shoes should be slip-ons or fastened with Velcro.
• Take "before" photographs prior to the operation, and make a written record of body measurements. These should include measurements of the neck, waist, wrist, widest part of hips, bust or chest, knees, and ankles, as well as shoe size. The preoperation photographs and measurements help to document the rate and amount of weight lost. Patients who have had weight loss surgery also point out that these records serve to boost morale by allowing the patient to measure progress in losing weight after the surgery.

PRE-OPERATION CLASSES AND SUPPORT GROUPS. In line with the Milliman and Robertson guidelines, most bariatric surgeons now have "preop" classes and ongoing support groups for patients scheduled for VBG and other types of bariatric surgery. Facilitators of these classes can answer questions regarding preparation for the operation and what to expect during recovery, particularly about changes in eating patterns. In addition, they provide opportunities for patients to share concerns and experiences. Patients who have attended group meetings for weight loss surgery often report that simply sharing accounts of the effects of severe obesity on their lives strengthened their resolve to have the operation. In addition, clinical studies indicate that patients who have attended preop classes are less anxious before surgery and generally recover more rapidly.

MEDICAL PREPARATION. Patients scheduled for a gastroplasty are advised to eat lightly the day before surgery. The surgeon will provide specific instructions about taking medications prescribed for other health conditions. The patient will be given preoperation medications that usually include a laxative to clear the lower digestive tract, an anti-nausea drug, and an antibiotic to lower the risk of infection. Some surgeons ask patients to shower on the morning of their surgery with a special antiseptic skin cleanser.