title: Risk Factors for Free Flap Failure in 2,846 Patients With Head and Neck Cancer: A National Database Study in Japan.
abstract: OBJECTIVE
  The risk factors for an unfavorable outcome after microvascular free flap reconstruction in head and neck cancer are not fully understood. We sought to identify factors affecting the occurrence of free flap failure.
  
  
  METHODS
  This was a retrospective cohort study using data from the national inpatient database in Japan between 2010 and 2012. We identified patients diagnosed with head and neck cancer who underwent tumor resection and consecutive free flap reconstruction. Cox proportional hazards regression was used to assess risk factors for free flap failure. The threshold for significance was P < .05. Missing data were imputed by using multiple imputation.
  
  
  RESULTS
  We identified 2,846 eligible patients. The overall proportion of free flap failure was 3.3%. Free flap failure was associated with diabetes mellitus (hazard ratio [HR], 1.80; 95% confidence interval [95% CI], 1.18 to 2.76; P = .007), peripheral vascular disease (HR, 4.49; 95% CI, 1.61 to 12.52; P = .004), renal failure (HR, 3.67; 95% CI, 1.45 to 9.33; P = .006), preoperative radiotherapy (HR, 2.14; 95% CI, 1.11 to 4.13; P = .022), and duration of anesthesia greater than 18 hours (compared with <12 hours; HR, 2.72; 95% CI, 1.19 to 6.22; P = .018).
  
  
  CONCLUSIONS
  Diabetes mellitus, peripheral vascular disease, renal failure, preoperative radiotherapy, and a longer duration of anesthesia were significant predictors of the occurrence of free flap failure.
authors: Graduate Student, Department of Clinical Epidemiology and Health Economics, School of Public Health, The University of Tokyo, Tokyo, Japan. Electronic address: miho-ishimaru@umin.ac.jp.
authors: Miho
authors: M
authors: Ishimaru
authors: Graduate Student, Department of Clinical Epidemiology and Health Economics, School of Public Health, The University of Tokyo, Tokyo, Japan.
authors: Sachiko
authors: S
authors: Ono
authors: Fellow, Department of Otolaryngology and Head and Neck Surgery, Faculty of Medicine, The University of Tokyo, Tokyo, Japan.
authors: Sayaka
authors: S
authors: Suzuki
authors: Research Associate, Department of Clinical Epidemiology and Health Economics, School of Public Health, The University of Tokyo, Tokyo, Japan.
authors: Hiroki
authors: H
authors: Matsui
authors: Professor, Department of Health Policy and Informatics, Tokyo Medical and Dental University Graduate School of Medicine, Tokyo, Japan.
authors: Kiyohide
authors: K
authors: Fushimi
authors: Professor, Department of Clinical Epidemiology and Health Economics, School of Public Health, The University of Tokyo, Tokyo, Japan.
authors: Hideo
authors: H
authors: Yasunaga
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016208:Databases, Factual; D005260:Female; D058752:Free Tissue Flaps / Q000009:adverse effects*; D006085:Graft Survival; D006258:Head and Neck Neoplasms / Q000601:surgery*; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D019651:Plastic Surgery Procedures / Q000009:adverse effects / Q000379:methods; D012307:Risk Factors