Active_comparator: Paravertebral Block

If the patient is randomized to group Paravertebral Block, the anesthesiologist performs TPVB after induction of general anesthesia. The patient is positioned in lateral decubitus position. The anesthetist performs the bilateral paravertebral block with ultrasound identification of the paravertebral space at the T4-T5 level. Slow injection of 0.3 to 0.35 ml / kg of ropivacaine on each side (diluted to 3.75 mg / ml = dilution in a 20 ml syringe with 10 ml of ropivacaine 7.5 mg / ml and 10 ml of NaCl 0.9%) after aspiration test.

Experimental: Erector Spinae Plane Block

If the patient is randomized to group Erector Spinae Plane Block, the anesthesiologist performs the ESPb block after induction of general anesthesia. The patient is positioned in a right lateral decubitus position. The anesthesiologist performs the erector block of the spine ESP with ultrasound identification at the T4-T5 level (identify the 1st rib on ultrasound then the space T4 to T5). Slow injection of 20 ml of ropivacaine on each side (diluted to 3.75 mg / ml = dilution in a 20 ml syringe with 10 ml of ropivacaine 7.5 mg / ml and 10 ml of 0.9% NaCl) after aspiration test.~The patient is then turned in left lateral decubitus position and the contralateral block is performed according to the same procedure.