Surgery for morbid obesity (bariatric surgery) has had a long and painful birth and childhood; has it finally come of age? It is more than 50 years since DeWind and Payne introduced the jejuno-ileal bypass.1 Whilst the procedure produced reasonable weight loss for the majority of patients, severe and often life-threatening complications coloured the views of many regarding surgery for morbid obesity for the next 4 decades.

With the rapidly increasing burden of obesity, improved surgical techniques, and the introduction of laparoscopic surgery, surgery for morbid obesity has become a ‘growth industry’; in 2004, it is estimated that more than 140,000 patients will undergo such surgery in the United States (US).

Surgery for weight loss involves two physical mechanisms and probably several endocrine mechanisms. The two physical mechanisms are either gastric restriction or malabsorption, or (as in the case of gastric bypass) a combination of the two. The endocrine mechanisms are more poorly understood but there is good evidence that the mechanism of actions of such surgery are far more than just a pure mechanical restriction of calorie intake or absorption. The effect of gastric bypass on the hunger-inducing hormone ghrelin has been well described,2 and it is likely that other gut-brain hormonal mechanisms are altered by bariatric surgery.

The data published in this issue of the Journal [He M, Stubbs RS. Gastric bypass surgery for severe obesity: what can be achieved?. N Z Med J. 2004;117(1207). URL: http://www.nzma.org.nz/journal/117-1207/1207] demonstrate that in a carefully selected series of patients treated by an experienced team the results of open Roux-y gastric bypass can be excellent. The results of this series are very similar to those contained within a recent meta-analysis of published data.3

There is now little doubt that bariatric surgery can result in improvements in quality of life and startling improvements in obesity related comorbidities, especially type 2 diabetes; the vast majority of patients with insulin resistance or type 2 diabetes will be rendered normoglycaemic by such surgery. For the patient and the surgical team, there is no more satisfying outcome that for a patient on huge quantities of insulin being rendered euglycaemic. The effects on comorbidities seem generally to be robust and sustained although there is some evidence that the effect upon hypertension may decrease with time.4

Even in the best series there is still morbidity (some of it significant) and occasional mortality associated with bariatric surgery. Most specialist bariatric surgeons would quote a risk of perioperative death of less than 0.5%; most of the deaths arising from cardiac or thromboembolic causes. A recent large overview series from the US would suggest that the 30-day mortality could be as high as 1.9%.5

In this series of patients, 81% of the deaths occurred in patients operated upon in the surgeon’s first 19 cases, emphasising that this is technically demanding surgery requiring a skilled and experienced surgeon and team for optimal outcomes.

Bariatric surgery requires commitment from both the surgical team and the patient. Only a minority of patients who are morbidly obese would consider such an approach; and of these, not all would be suitable. Thus, there is little doubt that good outcomes require a team approach and very careful patient selection.

Whilst there is ample case series data to quantify some of the effects of bariatric surgery, there are few examples of well-controlled trials looking at the full range of outcome data including quality of life and health economic data. It is important, therefore, that such data is generated so that the relative merit of this intervention can be appropriately and fairly judged against the multitude of other demands upon the healthcare dollar.

Should such procedures be available to patients in New Zealand through the public system? The answer is a qualified ‘yes’. It must be recognised that surgery is not going to solve the problem of the rapid rise in the levels of severe and morbid obesity, and indeed conventional healthcare approaches alone cannot deal with the problem. Society as a whole must adopt and implement strategies that deal with the fundamental issues behind the growth in obesity. These must occur at all levels including education, legislation, and perhaps fiscal measures.

Whatever these measures are, there are currently significant numbers of patients who could potentially benefit from such surgery. We have a treatment, albeit not perfect, which can (in carefully selected and informed patients) make significant improvement in their health status. Although the evidence supporting the use of bariatric surgery is substantial, much of it is poor in quality and there is a dearth of well-conducted trials.

Perhaps New Zealand should grasp this opportunity and instead of just introducing such surgery, do what should be done with all new treatments and carry out a well-conducted nationwide study to gather a full range of outcome data. The outcomes from such a study would not only benefit New Zealand but the wider international community, and if successful, it would set a fantastic precedent for the introduction of other procedures into the publicly funded healthcare system.

Author information: Iain G Martin, Head, School of Medicine, Faculty of Medical and Health Sciences, University of Auckland, Auckland

Correspondence: Professor Iain Martin, School of Medicine, Faculty of Medical and Health Sciences, University of Auckland, Auckland. Fax: (09) 308 2308; email: i.martin@auckland.ac.nz