Bariatric surgery: studies on its consequences with emphasis on thrombotic and bleeding complications

Obesity is a steadily growing problem that is associated with several diseases such as diabetes type 2, hypertension and dyslipidemia. For morbidly obese persons who have failed to achieve weight loss after several weight loss interventions, bariatric surgery is at this moment the only long-lasting, effective treatment. Bariatric surgery is not only an effective option to lose weight. It is also associated with significant improvement or remission of diabetes, cardiovascular risk factors and reduction in mortality. However, bariatric surgery is not without risk. Different complications can occur thereafter like venous thrombosis or bleeding complications. In this thesis different consequences of bariatric surgery are decribed. In part I, we focus on venous thrombosis and bleeding complications after bariatric surgery. We have explored the incidence and risk factors of these complications, evaluated the effect of severe obesity and bariatric surgery on low molecular weight heparin and vitamin K antagonists, and explored the problems that we encounter in diagnosing pulmonary embolism in these patients. In part II, we show also other consequences of bariatric surgery. We investigated the longer term effects of bariatric surgery on urinary sodium excretion which reflects dietary salt intake and change of metabolic stress after surgery. In addition, we investigated whether there is an influence of ethnic background on weight loss after bariatric surgery.