Evaluation of the Benefit of a New Surgical Procedure According to IDEAL Recommendations for ORL Cancer Patients: the External Pudendal Flap Used as a New Free Flap for Oral Cavity/Oropharyngeal Reconstruction to Limit Donor Site Sequelae

Inclusion Criteria: 1. Patient with a histologically proven diagnosis of head and neck squamous cell carcinoma (HNSCC) of the oral cavity or oropharynx. 2. Patient whose disease is classified UICC TNM stade (8th edition) : T0-4a N0/N2c M0 (no distant metastasis M0). 3. Patient whose oral cavity or oropharynx reconstruction requires a free fasciocutaneous flap according to an experienced oncology surgeon. 4. Patient OMS 0-1. 5. Age ≥ 18. 6. Patient with no contraindication to surgery. 7. Patient affiliated to a Social Health Insurance in France. 8. Patient able to participate and willing to give informed consent prior performance of any study-related procedures and to comply with the study protocol. Exclusion Criteria: 1. Patient with history of prior cervical surgery and/or radiation to the head and neck. 2. History of pelvic surgery and/or radiation to the pelvic area. 3. Patients with a contraindication to any form of sedation. 4. Patient with irreversible coagulopathy. 5. Patient with a contraindication to a CT scan or an injection of iodinated contrast medium. 6. Patient with active autoimmune disorders requiring immunosuppressive therapy, defined as receiving steroids (dose \> 10 mg of prednisone or equivalent) or other immunosuppressive therapy. 7. Pregnant or breastfeeding women. 8. Patient with another co-existing malignancy at the time of inclusion or any other significant medical, psychiatric, or surgical condition currently not controlled by treatment, which may interfere with the conduct of the study. 9. Patient with diabetes (type 1 or 2). 10. Patient with a BMI \> 30kg/m². 11. Any psychological, family, geographic or sociological condition that does not allow for compliance with the medical follow-up and/or procedures provided for in the study protocol . 12. Patient who has forfeited his/her freedom by administrative or legal award or who is under legal protection (curatorship and guardianship, protection of justice).