Introduction
Against a background of widespread obesity among all US age-groups, and the relative failure of conventional weight loss methods, doctors are increasingly resorting to gastrointestinal surgery in order to curb the rise of weight-related disease, and associated costs. An estimated 170,000 weight loss surgeries will be performed in 2005, and although the average bariatric surgery patient is a woman in her late 30s who weighs approximately 300 pounds, operations such as vertical banded gastroplasty and roux-en-Y bypass are now being successfully conducted on patients as young as 13 years.
But Does Bariatric Surgery Work?
While the increasing popularity of obesity surgery is a clear reflection of the inability of most obese patients to comply with conventional dietary treatments, the question remains: does this type of surgical treatment offer an effective solution for severe clinical obesity? To understand the issues raised by this question, let us examine the problem of obesity and how surgery attempts to reduce it.
How Widespread is Obesity?
According to current statistics, 61.3 million American adults (30.5 percent) are obese. In addition, an estimated 10-15 percent of children (ages 6?11) and 15 percent of teenagers are overweight and at risk of developing weight-related disorders. Severe obesity is also on the rise. Six million American adults are morbidly obese (BMI 40+), while another 9.6 million have a BMI of 35-40. (Source: US Census 2000; NHANES III data estimates)
How Does Obesity Affect Health?
Excess body fat associated with high body mass index (BMI) carries an increased risk of premature death. Obese patients (BMI 30+) have a 50-100 percent increased risk of death from all causes, compared with individuals of normal weight (BMI 20?25). Morbid obesity (BMI 40+) and super-obesity (BMI 50+) carries a still higher risk of dying younger. Most of the increased risk is due to co-morbid conditions like cardiovascular disease (atherosclerosis, heart attack or stroke). The effects of severe obesity on longevity are dramatic. Obese white males between 20 and 30 years old (BMI > 45) can shorten their life expectancy by 13 years. African-American men of similar age and BMI can lose up to 20 years of life. Obese white females between 20 and 30 years old (BMI > 45) can shorten their life expectancy by 8 years. African-American women of similar age and BMI can lose up to 5 years of life.
Research Into Obesity and Premature Death
A 12-year study of 330,000 obese men and 420,000 obese women, revealed that premature mortality rates for morbidly obese men were twice the normal: 500 percent higher for diabetics and 400 percent higher for those with digestive tract disease. In severely obese women, the mortality was also increased two fold, while in female diabetics the mortality risk increased eight fold and three fold in those with digestive tract disease. Another study of 200 men aged 23-70 years with severe clinical obesity, showed a 1200 percent increase in mortality in the 25-34 year age group and a 600 percent increase in the 35-44 year age group. Average cancer mortality rates are 150-500 percent higher in obese patients.
Other Obesity-Related Diseases
Aside from premature death, obesity is strongly associated with a wide range of health disorders. 80 percent of patients with type 2 diabetes are obese, while almost 70 percent of diagnosed heart disease is obesity-related. Other obesity-related disorders include: high blood pressure, cancer, carpal tunnel syndrome, depression, gallstones, gastroesophageal reflux (GERD), insulin resistance, low back pain, obstructive sleep apnea, musculoskeletal complaints and osteoarthritis, respiratory problems, stroke, and vein disorders.
Why is Surgical Treatment is Needed?
As the facts demonstrate, obesity is an independent risk factor for a number of serious diseases. Severe obesity, if left untreated, leads to life-threatening disorders and possible premature death. It is against this background that the viability of bariatric surgery should be assessed. Three key questions are: (1) Does bariatric surgery lead to a significant loss of weight? (2) What are the health benefits of surgery? (3) What are health risks?
Does Bariatric Surgery Lead To A Significant Loss of Weight?
Yes. According to most patient-surveys the health and weight reduction benefits of bariatric surgery exceed all other treatment methods by a wide margin. Weight loss surgery is considered successful when excess weight is reduced by 50 percent and the weight loss is sustained for five years. At present, average excess weight reduction at five years is 45-75 percent after gastric bypass and 40-60 percent after vertical banded gastroplasty. In a statistical review of over 600 bariatric patients following gastric bypass, with 96 percent follow-up, mean excess weight loss still exceeded 50 percent of initial excess weight at fourteen years. Another 10 year follow-up study from the University of Virginia reports weight reduction of 60 percent of excess weight at 5 years and in the mid 50's between years 6 and 10. A significant percentage of less-committed patients do regain weight 2-5 years after having surgery, especially those who undergo the less drastic stomach banding procedure, but if the patient is well motivated and given proper post-operative support, the weight loss is usually permanent. By comparison, according to one 4-year study of non-surgical weight loss programs involving obesity medication, behavior modification, diet and exercise, average weight reduction was 3 pounds in those subjects who were followed for the four years of the study.
What Are The Health Benefits of Surgery?
According to the International Federation for the Surgery of Obesity (IFSO), weight reduction caused by gastric reduction surgery improves longevity and reduces rates of premature death. In addition, hypertension is cured in about 50 percent of patients, while measurements of cholesterol and other blood fats show visible improvements, all leading to a reduction in the risk of heart disease. Type 2 diabetes is cured in 80 percent of diabetic patients while hyperglycemia and associated conditions such as hyperinsulimia and insulin resistance are even more likely to benefit from gastric bypass. Obstructive sleep apnea is cured in about 75 percent of patients, shortness of breath is relieved in 75-80 percent of cases, while asthma attacks are significantly reduced, particularly when associated with gastroesophageal reflux disease. Obesity surgery also relieves low back pain and arthritis, heartburn, urinary incontinence, and lower limb venous disorders.
What Are The Health Risks?
Generally speaking, the health complications of bariatric surgery divide into three classes. First, during the operation itself, patients are subject to the normal health dangers of any serious surgical procedure. Risk factors include: patient condition, the expertise of the bariatric surgeon and anesthesiologist and the quality of operating room services. Premature death occurs in about 1-2.5 percent of bariatric cases. Second, there are well-documented post-operative health risks, which largely depend on the type of procedure performed.
Post-Operative Health Problems of Gastric Banding
Restrictive procedures like gastric-banding and stomach stapling carry a number of short-term post-operative health risks, including: (1) Risk of hernia. About 10-20 percent of patients require additional surgery to fix problems like abdominal hernias caused by excessive straining after surgery before the incision heals. Laparoscopic surgery reduces this risk. (2) Risk of blood clots. About 1 percent of patients contract blood clots in the legs. (3) Risk of infection. On average, there is a 5 percent risk of infection in the incision area. (4) Risk of gastric staple breakage. This occurs in bariatric operations like vertical banded gastroplasty, that use staples to reduce stomach size. (5) Risk of band slippage and saline leakage. A routine complication, this occurs after lap band or other forms of adjustable gastric banding. (6) Risk of bowel obstruction. This rare complication may occur due to adhesions caused by scar tissue. (7) Risk of stomal stenosis and marginal ulcers.
Post-Operative Health Problems of Gastric Bypass
Post-operative health dangers of bypass procedures like roux-en-y or biliopancreatic diversion include: (1) Corrective operations. About 15-20 percent of bypass patients require follow-up gastrointestinal operations to correct complications (eg. hernias). These follow-up operations tend to carry higher risk of complication and death. (2) Dumping Syndrome. Caused by overeating or over-rapid eating, dumping, is not a real health danger, but symptoms (nausea, faintness, sweating and diarrhea) can be distressing. (3) Risk of nutritional deficiency. Since stomach bypass surgery involves bypassing the duodenum and part/all of the jejunum, causing insufficient absorption of vitamins and minerals, patients can develop deficiencies in nutrients like: iron, calcium, vitamin D and B12 deficiency. This can be easily corrected by a program of nutritional supplementation. (4) Risk of gallstones. About one-third of bypass patients develop gallstones. (5) Bowel Disorders. After all bypass operations, there is a period of intestinal adaptation during which bowel movements can be liquid and frequent. Typically accompanied by bloating, gas and foul smelling stools, this complaint may reduce with time, but occasionally becomes a permanent condition.
Bariatric Surgery is No Easy Answer To Obesity
Even though surgical methods are becoming more and more successful for the reduction of severe obesity, it would be misleading to present surgery as an easy option. To begin with, its success depends entirely on patient compliance with post-operative guidelines. And pressures to overeat do not disappear after surgery. If patients adhere to instructions, they tend to lose weight without regain. If they "cheat", they tend to regain most of their weight loss and may end up in a worse condition than before. Second, due to cost and availability issues, bariatric surgery can only ever treat a tiny percentage of the population who are severely obese. Third, we lack long term feedback on the success of these operations. For these reasons, it seems that bariatric surgery is no easy solution to our obesity epidemic.
David Johnson, LLb., is the senior researcher at http://www.bariatric-surgery.info which offers a range of information about gastric banding, stomach bypass and other weight-related surgeries to more than 2 million unique visitors per year.
Bariatric Surgery
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