Gastric bypass achieves good long term results. A recent long term follow-up study performed by MacLean et al defined post-operative success in gastric bypass surgery as a reduction in weight to a BMI <35 kg/m2. By this criterion, a successful outcome was achieved in 93% of patients whose initial BMI was less than 50 kg/m2, and in 57% of those with an initial BMI greater than 50 kg/m2 .
With restrictive procedures, sustained weight loss in the long term is not achieved according to the literature. Of 70 patients who underwent vertical band gastroplasty between 1985 and 1989, only 14 (20%) had experienced a durable loss of >50% of their excess weight . With the laparoscopic adjustable gastric band, results are quite mixed. A French study of 400 patients demonstrated a loss of 50% of excess body weight at 2 years follow-up  whilst in America, DeMaria reported on 37 patients and found that these patients lost only 18% of their excess weight at 3-18 months after surgery. >40% of the patients in the DeMaria series had their band removed, most commonly due to inadequate weight loss .
The results of up to 10 years of follow-up in the Swedish Obese Subjects Study also make interesting reading. Patients with a BMI of at least 34 (males) and 38 (females) who underwent Bariatric surgery were compared to those who had no surgery. The mean weight losses from baseline in the surgical group were 23% at 2 years and 16% at 10 years as compared to weight gains of <1% and <2% respectively in the control group . At the 10 year follow-up, 'recovery' from diabetes, hypertension, hypertriglyceridaemia, and hyperuricaemia (but not hypercholesterolaemia) was significantly more likely in the surgery group than in the control group; in addition, the new development of diabetes, hypertriglyceridaemia, and hyperuricaemia was less common in the surgery group .
Our study shows that Bariatric surgical procedures are relatively safe to undertake in view of the well established benefits. For vertical band gastroplasty, which had the largest cohort of patients, there was an initial reduction from the initial BMI for the patient population after surgery but this weight loss is not maintained, with regain of weight after ~40 months post-operatively (Figure 1). The reasons for this we hypothesise is that we feel these patients have a psychological need to overeat; the neostomach post-operatively initially mechanically restricts them from this but over time, the neo-stomach expands to accommodate this need to eat more and hence they regain weight. These results and the reasons for it are comparable to that for laparoscopic adjustable band gastroplasty.
Gastric bypass has the best results in this particular series (Figure 2). Weight loss is maintained in the long term and there is no regain of weight. The combined restrictive and malabsorptive components of this intervention appear to be the most effective intervention for weight loss in the long term.
We propose that further research in our centre is carried out into Bariatric surgery in terms of the health benefits i.e. the resolution of diabetes and sleep apnoea syndrome as well as the improvement in hypertriglyceridaemia and hypertension.
In conclusion, Bariatric surgery is safe with short to medium term weight loss being achieved. Gastric bypass is the most effective intervention and is currently being offered as the senior author's primary intervention.