In the UK in the last 10 years, the number of men defined as obese has increased by 75% (22.9% of the male population) whilst the number of women has also increased by a figure of 50% (23.5% of the female population) [2]. Morbid obesity is defined as a situation where an individual's BMI is greater than 40. Morbid obesity has been identified as a major risk factor for cardiovascular disease, hypertension, type II diabetes, cancer, psychological problems and sleep apnoea syndrome [3].

Diet and behavioural modifications have not been proven to be appropriately effective in the maintenance of weight loss over time. While several anti-obesity drugs are available, these rarely result in the loss of more than 10% of body weight [4]. At present, the only available therapeutic intervention that provides effective long term weight loss for the severely obese is Bariatric surgery [4].

According to NICE (National Institute for Clinical Excellence) guidelines in the UK, an individual can be offered Bariatric surgery if they fulfil the criteria as laid out in Table 1 [5].

There are two main types of surgery available to aid weight reduction and these are known as 'malabsorptive' and 'restrictive'. Malabsorptive surgery works by shortening the length of the digestive tract so that the amount of food absorbed by the body is reduced. This type of surgery involves creating a bypass by joining one part of the intestine to another [6].

Restrictive surgery limits the size of the stomach so that the individual feels full after eating a small amount of food. This type of surgery can involve stapling parts of the stomach together (vertical band gastroplasty), or fitting an adjustable tight band to make a small pouch for food to enter (laparoscopic gastric banding) [4]. Gastric bypass employs both restriction and malabsorption in the aim of weight loss.

Bariatric surgery is not carried out as extensively in the UK as it is in the US where it is more established. The aim of this study was to investigate the short, medium and long term outcome of Bariatric interventions carried out at the Walsall Manor Hospital in the West Midlands between 1990 and 2004.

Retrospective single centre audit of all Bariatric procedures carried out between 1990 and 2004 at the Manor hospital, Walsall. This is a district general hospital serving a population of approximately 275,000. Patient demographics, the primary procedure undertaken, side effects as well as secondary procedures undergone were recorded.

No ethical approval was required for this study. Audit approval was sought and obtained from the Local hospital audit department. No experimental research was performed during the course of this study. The treatment methods assessed are well recognised and established methods of Bariatric surgery.

For VBG, 40 out of 105 patients had weight gain by the 5th follow-up visit. This compared with 5 out of 18 patients after the same timescale for the GB group and 1 out of 6 in the LGB group.

Further intervention was required in 44 out of 129 cases. Stenosis in 28 of the 105 VBG patients resulted in oesophagogastroduodenoscopy (OGD) and dilatation; bowel obstruction (n = 9) and breakdown of anastomosis disruption (n = 7) out of the same group necessitated revision of the vertical band gastroplasty and subsequent gastric bypass.

For the gastric bypass group (n = 18), the post operative complications included incisional hernia (2/18), vitamin B12 deficiency (2/18) and superficial wound infection (2/18). In the laparoscopic gastric banding group (n = 6) there was one case of umbilical port access site herniation.

Figures 1, 2 and 3 show the change in BMI for the different interventions over time after surgery.

The percentage loss of initial BMI in the short medium and long term is illustrated in Table 4, Figure 4. There is an increased loss of BMI in the long term in the gastric bypass group (32.5%) when compared to the VBG group (14.97%). There was no regain of weight in patients who underwent gastric bypass, as compared to vertical band gastroplasty (27%), Table 5. There were no significant numbers of patients treated by LGB to enable a satisfactory comparative analysis.

Procedure	% Loss of initial BMI
	Vertical Band Gastroplasty	Gastric Bypass
Short Term (0-12 months)	28.44	24.85
Medium Term (13-36 months)	24.13	28.4
Long term (>36 months)	14.97	32.5

PROCEDURES	Gastroplasty	Gastric Bypass
	Vertical Band
	27	0

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 [7].

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 [8]. 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 [9] 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 [10].

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 [11]. 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 [12].

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.