Hepatomegaly is common in the morbidly obese patients and it may hamper the access to the hiatal region during bariatric surgery. The doctors made a preliminary prospective study that showed that a preoperative 4-week course of 1.500 Mg/ day without caloric restriction resulted in a 20 % reduction in the volume of the left liver lobe (segment 2 and 3) on ultrasounds.

The aim of this study is to determine whether a 4-week preoperative course with omega-3 without caloric restriction (1650 mg of omega-3 / day for 4 weeks) may reduce liver volume and its fat content, rendering thus surgery easier.

The primary end point is the reduction of the volume of the left liver lobe as measured by magnetic resonance imaging.

Secondary end points are: the reduction of the whole liver volume, liver steatosis, liver injuries during surgery, and duration of surgery, the evolution of liver tests as well as the correlation between preoperative MRI data and intraoperative liver biopsy for the quantification of liver steatosis.

Study design: This is an interventional, prospective, multicentric, randomized, double blinded clinical trial. Morbidly obese patients with metabolic syndrome candidate to bariatric surgery fulfilling criteria for bariatric surgery as established by the Haute Autorité de Santé are elegible for the study. Number of subjects to be enrolled: 44 patients in 12 months.

Study time schedule: At the time of the enrollment visit two visits are scheduled, the first before the beginning of the study and the last at the end. Surgery is scheduled no more than 7 days after the end of the treatment. At time of these two visits a clinical examination is performed avec calculation of the BMI, blood tests (ASAT, ALAT; GGT, total, HDL and LDL cholesterol, triglycerides, glycemia, C-peptide, HbA1c, insulin, HOMA-IR, C reactive protein) and a MRI to evaluate the volume and the fat content of the liver. At time of surgery duration of surgery and any eventual liver injury are recorded and a liver biopsy is performed.

The hypothesis is that, as shown by the preliminary study, the omega-3, will result in a reduction in the volume of the left liver lobe of 20 %.

Conclusion: If a 4-week preoperative course of omega-3 without caloric restriction results in a significant reduction of liver volume and steatosis before bariatric surgery, it may be recommended as a systematic preoperative treatment.

Inclusion Criteria:

• Age 18 - 60 years
• Karnofsky Index de > 70
• BMI > 35 kg/m2 associated with metabolic syndrome define by three or more of the following: waistline that measures at least 80 centimeters for european women and 94 centimeters for european men; High triglyceride level less than 1.5 g/l or specific medications; Reduced high-density lipoprotein (HDL) cholesterol less than 1.04 mmol/L in men or less than 1.3 mmol/L in women; Increased blood pressure 130/85 millimeters of mercury (mm Hg) or higher or specific medications; Elevated fasting blood sugar 100 mg/dL (5.6 mmol/L) or higher or specific médications.
• Failure of previous medical treatment of morbid obesity well conducted by a multidisciplinary team for at least 6 months.
• Multidisciplinary team agreement for bariatric surgery
• Patients affiliated to the French Health Care System (Sécurité Sociale)
• Patients having signed the informed consent

Exclusion Criteria:

• Contraindications to MRI (pace-maker, metallic foreign bodies, claustrophobia)
• Psychiatric contraindications to bariatric surgery
• Anesthesiology contraindications to surgery
• Progressive malignancies
• Chronic alcoholism (>30 gr/day)
• Uncontrolled sepsis
• History of liver disease
• Renal failure (Cockroft <30ml/min)
• Long term treatment with steroids
• Regular assumption of alimentary complements enriched with proteins and/or amino acids)
• Pregnancy (pregnancy test will be done before surgery in fertile women)
• History of bariatric surgery of supramesocolic surgery rendering the access to the hiatal region difficult.
• Forseeable difficulies in completing follow-up
• Patients under judicial protection
• Patients unable to understand or put in practice medical prescription as omega-3 oral supplementation.