151751-Najiba-Chargi

94 CHAPTER 6 ABSTRACT Background Fibula free flaps (FFF) are effective in accomplishing successful reconstruction for segmental defects of the mandible. Potential risk factors for FFF complications have been described in previous research, e.g., age, comorbidity and smoking. Low skeletal muscle mass (SMM) has shown to be an emerging predictive factor for complications and prognostic factor for survival in head and neck cancer. This study aims to identify the predictive and prognostic value of low SMM for surgical FFF related complications, postoperative complications and survival in patients who underwent mandibular reconstructionwith FFF after oral cavity cancer resection. Materials and methods A retrospective study was performed between 2002 and 2018. Pre-treatment SMM was mea - sured at the level of the third cervical vertebra and converted to SMM at the level of the third lumbar vertebra (L3). SMM at the level of L3 was corrected for squared height. Low SMM was defined as a lumbar skeletal muscle index (LSMI) below 43.2 cm 2 /m 2 . Results 78 patients were included, of which 48 (61.5%) had low SMM. Low SMMwas associated with an increased risk of FFF related complications (HR 4.3; p=0.02) and severe postoperative compli - cations (Clavien-Dindo grade III-IV) (HR 4.0; p=0.02). In addition, low SMMwas a prognosticator for overall survival (HR 2.4; p=0.02) independent of age at time of operation, ACE-27 score and TNM stage. Conclusion Low SMM is a strong predictive factor for FFF reconstruction complications and other postop - erative complications in patients undergoing FFF reconstruction of the mandible. Low SMM is also prognostic for decreased overall survival.