Obesity and its complications have a significant effect on morbidity and mortality in these subjects. Especially at risk are subjects with extremely increased BMI (above 99th percentile for age and gender in adolescents). In these subjects classical treatment with diet and cognitive therapy has a limited effect. Bariatric procedures, at the moment, are the only feasible therapeutic possibility.

Bariatric procedures are based on several principles; restrictive, malabsorptive and combined. They can be surgical or endoscopic. The later are used in subjects that do not qualify for surgical procedures that decline them or are used before a planed definite bariatric procedure.

Duodena-jejunal liner (DJL) is an endoscopic tool, that is efficiently and safely used to decrease body weight and ameliorated obesity complications, especially those associated with diabetic state.

Aims of the study are:

• To determine (short and long-term) efficacy of DJL in decreasing body weight in adolescents.
• To determine (short and long-term) efficacy of DJL in ameliorating complications of morbid obesity - abnormal glucose metabolism, dislipidemia, altered adipokine secretion pattern, altered secretion pattern of gastrointestinal hormones in adolescents.
• To visualize functional alternations in the selected central nervous system regions associated with appetite regulation upon insertion of DJL.
• To evaluate psychological outcomes; change in emotional and behaviour problems, in body image, in eating disorder symptoms.

Inclusion Criteria:

• Subjects estimated to fully comply with study protocol and have signed an informed consent form.
• Age > 15 years.
• BMI ≥ 99. percentile for age and gender.
• Inefficient conservative measures (of at least 6 months duration) to decrease body weight (characterized as a decrease in BMI > 10 %).
• Documented negative pregnancy test in women of childbearing potential.
• Women of childbearing potential agree to remain on contraceptives for the duration of their trial participation.

Exclusion Criteria:

• Previous GI surgery that could potentially affect the ability to place sleeve or affect the function of the implant.
• Subjects with congenital or acquired anomalies of the GI tract which in the opinion of the investigator, may impair implantation of the EndoBarrier device.
• Subjects who had gastrooesophageal reflucs disease..
• Known abnormal pathologies or conditions of the gastrointestinal tract, including ulcers or Crohn's disease, upper gastro-intestinal bleeding conditions.
• Coagulopathy defined as Hgb <10g/dl and platelet < 100,000/ml or diagnosis of other severe coagulopathy like hemophilia.
• Any documented history of acute or chronic pancreatitis.
• Subjects requiring regular antithrombotic therapy (i.e. anticoagulant or antiplatelet agent).
• Known diagnosis of systemic lupus erythematosus, scleroderma or other autoimmune connective tissue disorder.
• Subject is or has been enrolled in another investigational study within 6 months of participation into the EndoBarrier study.
• Subjects who are mentally retarded or emotionally unstable.
• Subjects who are pregnant or were breastfeeding.
• Subjects with an abnormal laboratory or ECG abnormality which the investigators deems clinically significant and makes the patient a poor candidate for the study.