Bariatric surgery works, we just need to ensure it's safe

Around 2.6 million Australians are obese. Obesity causes contribute to diseases such as diabetes, high blood pressure, obstructive sleep apnoea, infertility, depression and cancer. The strength of the causal link between obesity and these diseases means that obesity is now considered at least equal to smoking as a preventable cause of premature death.

The total annual cost of obesity in Australia, including health system costs, productivity declines and carers' costs, is estimated at around $58 billion (Access Economics 2008). 

The morbidity and cost associated with obesity (as well as its prevalence) has led Australian governments to recognise the condition as a chief health priority, at federal and state levels.

Weight loss has the potential to be one of the most important health care interventions in our community. The problem is that diet and exercise programs are typically only successful in the short term. Only three per cent of those who successfully lose weight can maintain that weight loss beyond three years. This is not because these individuals are in some way inept or unwilling, but because the body is designed to defend fat mass.

Hunger is a primitive instinct. In evolutionary terms, fat stores represented stored energy that was important in case of famine. Therefore, when an individual loses weight, the body strives to replace the energy stores that have been depleted. The metabolic rate slows down so that individuals who seek to achieve substantial weight loss and maintain that new level need only 1200 kCal (1000 calories) a day – the equivalent of three entrée sized meals. If more than this very small amount of food is consumed, weight will be regained.

In addition, losing weight shifts our hormonal balance so that we become hungry, making it almost impossible to adhere to this stringent long-term need for caloric restriction. In a society where there is an oversupply of tasty, attractive, hygienic food that is low in cost, marketed well and very much a part of our cultural life, it is difficult to not eventually satiate that need.

Medications have been tried to help tackle either the hunger associated with weight loss or the metabolic slow down. Unfortunately side effects have led to most being withdrawn from the Australian market.

Obesity (bariatric) surgery is considered when an individual has tried, and failed, to lose weight by conservative means. Results from specialist centres and clinical trials suggest that these procedures provide significant weight loss safely and that weight loss persists beyond 10 years. Along with this weight loss there is significant improvement in the illnesses associated with obesity and quality of life. Importantly, obese persons who elect to undergo bariatric surgery appear to live longer than obese persons that do not undergo surgery.

On the basis of these results there has been a rapid expansion in the number of bariatric procedures performed in Australia annually. It is estimated that around 15,000 procedures will be undertaken across Australia in 2012, up from 5000 in 2005.  Whilst the results from specialist centres suggest that the surgery is safe, there is no such thing as a risk-free surgical procedure.

All of these procedures do carry risks such as bleeding, blood clots, infection, device or staple line failure. We currently have little information on the quality and safety of the surgery being performed in the general community, outside of specialist centres, and no way of tracking the long-term safety and results.

To address this, a bariatric registry has been established by the Obesity Surgery Society of Australia and New Zealand in conjunction with the Monash University NHMRC Centre for Research Excellence in Patient Safety. Currently in its pilot phase, the registry aims to capture and track all bariatric procedures performed across Australia and New Zealand, focusing not only on the safety of the initial procedure but also longer-term effects on weight and health, as well as the longer-term adverse events.

Quality and safety registries have been shown to improve health outcomes. Monitoring of outcomes following orthopaedic surgery through the Australian Joint Replacement Registry, for instance, recently led to the withdrawal of a defective hip prosthesis from the market.

The establishment of this registry is in line with the 2008 recommendations of the Australian Commission on Safety and Quality in Healthcare and the 2009 Health Technology Review report.

There are also two specific recommendations for the establishment of a bariatric surgical registry: the Georganas Senate inquiry into obesity (2009) and the 2011 Medical Benefits Reviews Task Group.

Whilst prevention would be the ideal, the fact is that we are now faced with a situation where 24 per cent of our population need help to lose weight and then keep that weight off.

Bariatric surgery appears to be a safe, reliable option for people who have failed to lose weight through more conservative means. The establishment of a bi-national bariatric register will provide confidence to patients, surgeons, funders, hospitals and the wider community that bariatric surgery is safe and is achieving improvement in health outcomes to patients at a population level.