The aim of the study is to compare the analgesia provided by the serratus plane block with local infiltration of the orifices of the trocars after thoracic robot-assisted surgery.

In our hospital, the current practice to provide post operative analgesia for patients scheduled for robot-assisted mitral repair or oncological thoracic surgery is to dispense local anesthetics at the orifices of the trocars at the end of the surgery and to give a Patient Controlled Analgesia (PCA). Some of these patients are not comfortable and we observe a large percentage of chronic pain. Recently we tried to use the Serratus plane block realised before the beginning of the surgery, and it seemed that patients were more comfortable with a lower consumption of morphine. So we decided to perform a double blind, randomized study in this population of patients to compare the analgesia provided by the serratus plane block realized before the beginning of the surgery and the local infiltration of the wound at the end of the surgery.

Inclusion Criteria:

• mitral repair, coronary artery revascularization or thoracic surgery scheduled robot-assisted surgery

Exclusion Criteria:

• non robot-assisted surgery

The patient where randomized by the investigator after inform consent was signed The investigator prepared the syringes named "serratus" and "local" with levobupivacaine 0.25 or saline according to randomization The care provider injected the prepared syringes respectively in the serratus plane or locally without knowing their contents The outcome assessor evaluated the post operative pain and the 3 months followup without knowing the randomization