Inclusion Criteria:  Male or female patient over 18 years of age Membership in a mandatory health insurance plan Patient treated for a first median nerve liberation surgery at the carpal tunnel Patient having been informed of the study and having given informed consent French-speaking patient  Exclusion Criteria:  Surgical revision  Contraindication(s) to loco-regional anesthesia :  Coagulation disorder or ongoing anticoagulant therapy Existing peripheral neuropathy Amide-type AL allergy Pregnant or breastfeeding women Inability to undergo the medical follow-up of the study for geographical, social or psychological reasons Patients under legal protection Patients under the influence of drugs that may interfere with the anesthetic techniques under study (cocaine, cannabis, etc. as judged by the investigator) Inclusion of the subject in another research protocol during this study