BACKGROUND: A prospective, randomized trial comparing vertical banded gastroplasty (VBG) and gastric bypass (GB) was performed on 106 patients between 1987 and 1990. METHODS AND RESULTS: Failures of these two operations (manifested by failure to lose weight, late weight gain or intolerance of adequate oral intake) were treated by means of a third operation, isolated gastric bypass (IGB), in which the small gastric pouch was isolated from the gastric fundus. The latter operation was significantly better than VBG or GB and achieved a 63% success rate, i.e. body mass index (BMI) < 35 kg m(2) and less than 50% excess weight. During the year following this trial an additional 54 patients underwent IGB. When this operation was performed for morbid obesity and was the Initial procedure, 96% of the patients achieved a successful result. If IGB was performed as a revision procedure or for super obesity (BMI > 50 kg m(2)), the success rate was 63% with 100% follow-up at 40 months. Major morbidity occurred in six of the 160 patients who underwent 195 operations (the trial period and subsequent year). There were no deaths and follow-up was 98%. CONCLUSIONS: The ideal gastric operation based on this study emphasizes the following requirements: a small pouch (< 15 ml) totally separated from the stomach, a pouch not dependent on staples, placed in the dependent position to prevent stasis, constructed without foreign material and with an anastomosis which permits ingestion of solid food.

BACKGROUND: There is a familial predisposition to obesity. We wished to document the incidence of obesity (BMI > 40 kg m(2)) in the immediate relatives (parents and siblings) of obese patients who were candidates for gastric restrictive surgery. We determined if a familial predisposition to obesity would influence the surgical results. METHODS: The height, weight and BMI were obtained in 1841 relatives of obese patients and in 1059 relatives of normal weight controls. The results of gastric surgery after 52.9 +/- 23.1 months were obtained in 44 patients with a familial history of obesity and in 34 patients without a familial history. RESULTS: Patients presenting with a BMI > 40 kg m(2) were 24.541 times more likely to have a first degree relative with morbid or super obesity than individuals in the control group. Mothers were twice as likely to be severely obese as fathers. A successful result (BMI < 35 kg m(2) or less than 50% excess weight) occurred 52.9 +/- 23.1 months in 77% of patients with a family history of obesity.and in 73% of patients without a familial predisposition (p = 0.79). CONCLUSIONS: There is a strong familial predisposition to obesity but over one-half of the immediate family members of obese patients have a BMI < 30 kg m(2). Gastric restrictive surgery induces satiety and produces a successful outcome regardless of familial predisposition. Patients who undergo surgery have a remarkably stable weight over the year prior to operation, suggesting they are defending a markedly elevated BMI.