Today, rarely a day goes by without a new headline highlighting the perils of the international obesity ‘epidemic’. Well-established health risks associated with obesity include heart disease, stroke and diabetes to name but a few, and the cost of treating them (estimated at over $100 billion per year in the USA), not to mention the economic cost of premature mortality and lost days from work, provides a clear rationale for intervention. Treatments include behavioural, medical and surgical techniques, and although the latter should only be considered when patients’ non-surgical attempts have failed, the rates of these ‘bariatric’ surgical procedures continue to rise.
The first case reported in the medical literature was the ‘jejuno-ileal bypass’ performed by Dr Kremen and his colleagues in Minnesota in 1954. This spawned an era of advancement in bariatric techniques, with the last 50 years seeing a significant increase in the diversity of types of procedure, and an improved understanding of long-term benefits and complications.
Weight loss is generally achieved by two methods in bariatric surgery: malabsorptive and restrictive procedures. Malabsorptive procedures, achieve weight loss by decreasing the effectiveness of nutrient absorption in the gut, through shortening the length of functional small bowel. Restrictive procedures, on the other hand, reduce the capacity of the stomach and thereby the caloric intake, by inducing early satiety – they simply cause the patient to feel ‘full up’ earlier. An example of a purely restrictive method is “gastric banding”, in which an adjustable inflatable device is placed around the upper part of the stomach. This method benefits from being adjustable, reversible, and achieved through minimally invasive ‘keyhole’ surgery. Malabsorption and restriction can be achieved by a popular technique known as ‘Roux-en-Y’ bypass, which involves creating a small stomach pouch, and shortening the length of functional small bowel. Even this technique, which requires considerable re-plumbing of the intestinal tract, is now being performed through keyhole techniques by experienced surgeons.
When patients who have undergone bariatric surgery are compared to age, sex and weight-matched obese subjects, the benefits are shown to be very promising in the medium and long-term. Surgical techniques have not only been shown to achieve an average excess weight loss of around 60%but also resolution or improvement of diabetes, high blood pressure, high cholesterol and sleep apnoea in 60-80% of patients. This translates to a reduction in mortality of around 30-40% at 10 years. The benefits of medical and behavioural treatments pale in comparison.
Of course, all surgery comes with its complications. Although Dr Kremen and his team saw their early procedure produce significant weight loss, many patients also suffered the unacceptable consequences of severe diarrhea, dehydration, electrolyte imbalances, and in some cases acute liver and kidney failure. The procedure is no longer performed due to its unacceptable mortality and complication rate. In Dr Kremen’s day, and for almost four decades following, before the advent of keyhole surgery, all weight loss procedures required invasive surgery with longer hospital stays and considerable complications. Today, the 30-day mortality rate has dropped to less than 1%. Complications vary according to procedure, and although those such as blood clots and bowel leaks (at sites where bowel is rejoined surgically) can be serious, the overall incidence of significant complications requiring rehospitalisation is much reduced.
Bariatric surgery is a topic that tends to split opinion amongst the general public. Questions of ethics and morality are often raised. Do these surgical techniques incentivise unhealthy lifestyles? Are we allowing people to over-indulge without considering the repercussions, by providing a cure as opposed to concentrating more on prevention? Regardless of any such objections, it is clear that surgical techniques have a place in the field of bariatrics and have been shown to benefit a large proportion of those undergoing these procedures. With continued advancements in medical technology and increasing rates of obesity in the developed and developing world, the meteoric rise of bariatric surgery may continue for many years to come.
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