the excluded stomach during sleeve gastrectomy can be investigated post removal outside the patient. During stapling it is common to reduce systolic arterial blood pressure (SAP) below 100 mmHg to reduce peritoneal perfusion and have better compression. Higher intra abdominal pressures reduce also the peritoneal and mucosal perfusion and might help to improve stapling compression. Stapling compression can be evaluated by measuring stapling thickness and compare it with stomach wall thickness or by measuring leaks during leak test or better outside the patient on the excised stomach with a bursting pressure.

Patients are randomized to two groups: group standard perfusion means that the SAP is kept between 100 and 140 mmHg by adapting depth of anesthesia, by level of post expiratory pressure or by giving vasoconstriction.

low perfusion group means that

1. systolic blood pressure is kept below 100 mmHg from the first linear staple till the last by using a Clevidipine infusion to regulate the blood pressure accurate just below 100 mmHg for a short time while needed.
2. goal directed fluid therapy using 100 ml/h fluid intravenous and extra load of fluid if pulse pressure variation > 20 %
3. increase intra abdominal pressure (IAP) up to 20 mmHg inly during stapling and return to minimum IAP needed to achieve 3 liter workspace.

The resected stomach is removed and analyzed outside the body before throwing away:

Inclusion Criteria:

• primary sleeve gastrectomy

Exclusion Criteria:

• allergy to one of the drugs used intra operative
• liver, renal, cardiac or lung disease with limited function

normal perfusion