Gastric Bypass Facilitating the Procedure and Long-term Results

University dissertation from Uppsala : Acta Universitatis Upsaliensis

Abstract: Gastric bypass achieves weight loss in the morbidly obese. Preoperative weight loss is used to reduce the enlarged fatty liver that otherwise reduces visibility during surgery. The purpose of gastric bypass is to provide patients with long-term weight loss. The aim of this thesis was to investigate the result of preoperative low calorie diet on liver volume and to evaluate the long-term result of gastric bypass.Paper I showed that four weeks of low calorie diet reduces intrahepatic fat by 40% and facilitates surgery mainly through improved visualisation. Paper II demonstrated that all of the reduction of liver volume occurs during the first two weeks of treatment with low calorie diet.  In paper I liver volume was reduced by 12% and in paper II by 18%. Paper III focused on long-term results and showed that gastric bypass achieves a mean 63% excess body mass index loss in obese patients after 11 years. However, of these 40% undergo abdominoplasty and 2% require additional bariatric surgery. Only 24% adhere to the lifelong recommendation on multivitamins and 72% to Vitamin B12 recommendations. Paper IV evaluated gastric bypass as a revisional procedure after earlier restrictive surgery had failed. Similar weight results as after primary gastric bypass are attained. No patient taking vitamin B12 supplementation was deficient at follow-up, regardless of whether the vitamin was taken as a pill or as intramuscular injections.