Postoperative Pain Management After Minimally Invasive Aortic Valve Surgery

Patients undergoing minimally invasive aortic valve replacment surgery will be enroled in the study, after giving a signed informed consent. The study evaluates the efficacy of local anesthestic application through the catheter in the surgical wound for the postoperative pain relief after minimally invasive aortic valve surgery. Patients will then be randomised in two groups according to the protocol: 1. group: continous infusion of the local anesthetic plus bolus on demand 2. group: continous infusion of saline plus bolus on demand All patients will receive Metamizol every 12 hours plus bolus of piritramid on demand. Analgesia effectivness will be checked hourly according to the visual analogue scale (VAS). According to protocol, bolus will be given every time the score of VAS scale is \>3. The catheter will be removed 48 hours after the protocols' start.