On obesity surgery

Abstract

Obesity surgery is the only option that has proven to result in adequate and sustained weight loss in severely obese patients. The aims of this thesis were to elucidate the differences between two fundamentally different surgical techniques used in obesity surgery¯ gastric bypass and Vertical banded gastroplasty (VBG) ¯ in a broad perspective together with an assessment of the safety and efficacy of a laparoscopic approach. The series wherein laparoscopic techniques were established to perform gastric bypass and vertical banded gastroplasty (VBG) are presented together with the long-term outcome in terms of weight loss and remedial surgery. In a randomized clinical trial using the two techniques variables assessed were: the perioperative results, complications and recovery rate together with the outcome in terms of BMI, body composition, basic metabolic rate (BMR) and dietary intake.There were a number of postoperative complications in the initial series of laparoscopic gastric bypass, but weight development was superior after gastric bypass and there was no need for remedial surgery in order to maintain weight loss, as compared with a substantial need following VBG. In the randomized study the operative risk was shown to be low and acceptable after both procedures, although the number of reoperations was higher and OR time was longer after gastric bypass. Postoperative mobilization and recovery were equivalent after gastric bypass and VBG. Weight reduction amounted to 85% vs. 60% of excess weight loss, respectively, two years after gastric bypass and VBG. Moreover, 17% of VBG- patients were reoperated with gastric bypass during the first two years after primary operation. Body composition studies revealed the greater weight loss after gastric bypass to be due to better reduction of body fat. The lean tissue mass was better preserved in weight loss after gastric bypass than after VBG. All measurements in anthropometry had better improvements after gastric bypass than VBG. BMR decreased as expected in proportion to the weight loss after both procedures. Patients operated on with gastric bypass were able to eat all foods but avoided fatty foods, while patients after VBG avoided vegetables, whole meat and bread. Patients operated on with gastric bypass had a decreased and smaller proportion of dietary energy from fat than after VBG. In summary, all body composition parameters after gastric bypass compared favorably to VBG, with protection of LTM in superior reduction of fat. Eating patterns were also better after gastric bypass and demonstrated a steering away from fatty foods which, in fact, could be a part of the mechanism of action in gastric bypass. The laparoscopic approach offers advantages in obesity surgery.