We commend the authors (Martin I. Bariatric surgery: folly or the future? [editorial]. URL: http://www.nzma.org.nz/journal/117-1207/1209 and He M, Stubbs R. Gastric bypass surgery for severe obesity: what can be achieved? [original article] URL: http://www.nzma.org.nz/journal/117-1207/1207) on their bariatric surgery papers in the 17 December 2004 issue of the Journal. The papers were timely, and contained some important messages. However, some issues raised require further discussion.

As mentioned previously, bariatric surgery is not new. Gastric bypass surgery has been around for over 30 years. Improved surgical technique and perioperative care over this time now result in clear health benefits from gastric bypass surgery.1 For instance, bariatric surgeons at MacGill University Health Centre (MUHC), Montreal, Canada, in an observational 2-cohort prospective study, have shown that gastric bypass surgery decreases long-term mortality (0.68 % versus 6.17%), morbidity, and the use of healthcare resources in morbidly obese patients.2

When compared to non-operative management in severely obese patients, bariatric surgery is increasingly shown to have better outcomes and cost-effectiveness,3even in the absence of evidence from well-constructed randomised clinical trials. Many operations are currently considered to be “gold standard” treatments despite a lack of randomised clinical trials to support their use. Such examples include laparoscopic cholecystectomy, total mesorectal resection of rectal tumours, and liver resection.

Surgeons trained in gastric bypass surgery, with appropriate workloads to maintain skill level, achieve excellent results.4 The volume-outcome relationship is, however, a complex issue. Preoperative assessment and treatment of comorbidities; perioperative care via anaesthetists, intensivists and ward staff; plus input from nutritionists, physiotherapists, and psychologists are all important components in achieving good outcomes. Intuitively these variables are likely to be of higher quality in a large-volume unit. It is imperative that low-volume units (<25 procedures/year) strive to maximise such supportive care if they are to achieve similar outcomes.

In the USA, an emerging bariatric operation amongst the American Society for Bariatric Surgery is laparoscopic gastric banding. In Australia, it is the primary operation.5 There is no randomised, clinical trial comparing laparoscopic banding with gastric bypass surgery. Part of the reason for this is there is no universally accepted gastric bypass procedure.

One area of ongoing debate is the role of laparoscopic adjustable banding and laparoscopic gastric bypass surgery. Gastric bypass is associated with greater resolution of comorbidities and less mortality than laparoscopic banding.6 To date, this has not been demonstrated with adjustable banding; however, the attraction of laparoscopic banding, its safety, adjustability, reversibility and relative ease of surgical input are attractive features for the patient and surgeon alike.

Hopefully, in time, randomised clinical trials will be performed to compare these procedures in units with large volume and experience in both techniques; however, it is very unlikely such a trial would be able to get off the ground in New Zealand.

When comparing outcomes of operative techniques, it should be noted that, since the introduction of laparoscopic surgery, the length of hospital stay has fallen significantly in most instances. As surgeons gain more confidence in discharging postoperative patients sooner after laparoscopic procedures, it is expected that length of stay will also be reduced in patients after open procedures. We are already seeing this trend at North Shore Hospital. Our median stay for laparoscopic bypass is 3 days. As a result of our experience with laparoscopic early discharge, we have now been able to discharge many of our open gastric bypass patients on postoperative days 3 or 4.

We agree that bariatric surgery should be performed in the public system in New Zealand. However it must be emphasised that good outcomes from surgery are achieved in patients who are committed to weight-reduction lifestyles through sensible diet and exercise regimes. In the absence of severe obesity comorbidities, patients should only be offered surgery in the Public Sector after demonstrating compliance to some simple advice regarding exercise and lifestyle.

There are currently limited resources in New Zealand to offer bariatric surgery to all those who would benefit from it. Aside from funding issues, there is also a paucity of surgeons working in the public system trained in bariatric techniques. Hence the upper gastrointestinal surgical trainee is currently likely to receive minimal exposure to bariatric surgery.

We echo Professor Martin’s comment on the need for a nationwide database on outcomes from bariatric surgery in both the public and private systems. To add weight to the above statements, it is imperative that results from bariatric surgery continue to be published.

North Shore Hospital, Auckland, has been running a bariatric surgery programme since October 2001. We have been collecting data prospectively on patient outcomes following weight reduction surgery in the public system. These results will be from a population of carefully selected patients with proven compliance to lifestyle advice, or patients with severe obesity-related comorbidities. This represents a somewhat different population to those from the Wakefield Hospital Study and will hopefully add further evidence that modern bariatric surgery is safe and produces good outcomes for both the patient and society at large.