151751-Najiba-Chargi

103 Surgery: skeletal muscle mass and free fibula flap reconstruction DISCUSSION Low skeletal muscularity has been associated with increased mortality of all cause in the el- derly. 24–26 The prognostic significance of sarcopenia on survival and treatment complications is of increasing interest in cancer patients. Sarcopenia has been studied broadly in patients with colorectal, esophageal and lung cancers. In these groups of cancer patients, it is associated with increased surgical morbidity and mortality. 11,27,28 To the best of our knowledge this is the first study to study the influence of SMM on microvas- cular free flap reconstruction outcomes in patients undergoing surgery for oral cavity cancer. In this study low SMM was a powerful independent and negative predictive factor for the occurrence of flap failure and complications after mandibular reconstruction in HNC patients. Patients with skeletal muscle depletion were significantly more likely to develop early or late flap related complications such as flap dehiscence, skin island necrosis, thrombosis and fail- ure. Low SMMwas also seen as a risk factor for patients in this study cohort to develop severe (non-flap related) postoperative complications, which were graded by the Clavien-Dindo Classification. In line with this study are recent studies that have investigated the effects of low SMM in HNC patients undergoing total laryngectomy. 28,29 These studies reported prolonged hospital stay, wound related complications, pharyngo-cutaneous fistula and diminished overall survival. Low skeletal muscularity was also found to be an independent prognostic factor influencing OS, independent of HPV status, in patients with advanced oropharyngeal cancer. 30,31 In pa- tients undergoing primary chemoradiotherapy with advanced stage head and neck squamous cell carcinoma it is associated with increased chemotherapy dose-limiting toxicity (CDLT) and decreased OS. 17 The exact underlying mechanism of how preoperative sarcopenia attributes to increased microsurgical flap complications and other adverse surgical outcomes is still subject to fur- ther investigation. Low skeletal muscularity is a multifactorial syndrome which is induced by heterogeneous conditions which can be cancer-specific and non-cancer-specific. Cancers constitute amicroenvironment of inflammation induced by the presence of inflammatory cells, chemokines and cytokines; a phenomenon known as cancer-related inflammation. 32 Feliciano et al. have studied in a large cohort of colorectal cancer patient the association between sar - copenia and systemic inflammationmeasured by the neutrophil-to-lymphocyte (NLR) ratio. 33 They have found that an increased NLR ratio is associated with sarcopenia and hypothesized that this is an intertwined mechanism in which inflammation underlies muscle wasting and is in itself reinforced by it. These inflammatory mediators promote a catabolic mechanism in which there is a rise in protein breakdown coupled with decreased synthesis. This can lead 6