This study compare the "Serratus block plane" (SPB) and the local infiltration of the tissue in the prevention of acute and chronic pain after breast cancer surgery.

Chronic pain after breast surgery may be severe, often requiring the use of morphine. The incidence of chronic pain varies from 27 to 50% depending on definitions.

The infiltration of tissues by a local anesthetic is a simple, fast and low risk technique but of limited effectiveness.

Serratus the flat block, performed under ultrasound guidance, is minimally invasive and easy to perform. It allows anesthesia and analgesia to an extended part of the anterolateral chest wall and the axilla. This regional anesthesia technique provides good analgesia during and after breast surgery, but remains to be evaluated; beyond perioperative analgesia, the benefit-risk, post operative rehabilitation, and the impact on ambulatory and on chronic pain are fundamental objectives.

Inclusion Criteria:

• Women scheduled for elective breast neoplasm surgery
• Of ASA classification 1, 2 or 3
• Patients who provide written informed consent

Exclusion Criteria:

• Minor patients
• Patients refusing to sign the consent
• Patients included in another protocol within 3 months
• Pregnant or lactating patients
• Patients with history of allergy to local anesthetics (Ropivacaine)
• Patients with contraindication to regional anesthesia (coagulopathy, local infection ...)
• Patients with history of prior breast surgery (excluding diagnostic biopsy)
• Patients with history of chronic pain
• Patients with a history of psychiatric disorder