title: Nasoseptal flap reconstruction of high flow intraoperative cerebral spinal fluid leaks during endoscopic skull base surgery.
abstract: BACKGROUND
  Over the past 10 years, significant anatomic, technical, and instrumentation advances have facilitated the exposure and resection of intradural lesions via a fully endoscopic expanded endonasal approach (EEA). The vascularized nasoseptal flap (based on the posterior nasoseptal artery) has become our primary endoscopic reconstructive technique. The goals of this study are to prospectively evaluate the nasoseptal flap and high-risk cerebral spinal fluid (CSF) leak variables.
  
  
  METHODS
  Prospective evaluation was performed of EEA patients with intraoperative high-flow leaks (either a cistern or ventricle open to nasal cavity during tumor dissection) who underwent nasoseptal flap reconstruction.
  
  
  RESULTS
  Seventy consecutive nasoseptal flaps for high-flow intraoperative leaks were evaluated prospectively by the primary author. Twelve risk factors were then graded at the time of the operations and correlated to CSF leak outcomes. The overall postoperative CSF leak rate was 5.7% (4/70). All four postoperative leaks were successfully managed with endoscopic repair and CSF diversion. A multivariate analysis of all 12 risk factors is detailed. Pediatric patients, large dural defects, and radiation therapy were noted to be factors in reconstructive failure. One flap death occurred in a patient with prior surgery and proton therapy, this leak was managed with a temporoparietal flap and endonasal repair.
  
  
  CONCLUSIONS
  The nasoseptal flap is an excellent anterior skull base reconstructive technique. Patients with high-flow intraoperative CSF leaks had a 94% successful reconstruction rate. Patients with skull base proton radiation therapy are at higher risk for flap failure and preparation for nonradiated tissue reconstruction should be discussed with the patient.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599, USA. azanatio@med.unc.edu
authors.forename: Adam M
authors.initials: AM
authors.lastname: Zanation
authors.forename: Ricardo L
authors.initials: RL
authors.lastname: Carrau
authors.forename: Carl H
authors.initials: CH
authors.lastname: Snyderman
authors.forename: Anand V
authors.initials: AV
authors.lastname: Germanwala
authors.forename: Paul A
authors.initials: PA
authors.lastname: Gardner
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Prevedello
authors.forename: Amin B
authors.initials: AB
authors.lastname: Kassam
mesh_terms: D000367:Age Factors; D002648:Child; D018450:Disease Progression; D004724:Endoscopy; D005260:Female; D006801:Humans; D007431:Intraoperative Complications; D008297:Male; D009300:Nasal Septum / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000601:surgery*; D011379:Prognosis; D011859:Radiography; D019651:Plastic Surgery Procedures; D012307:Risk Factors; D019291:Skull Base / Q000033:anatomy & histology / Q000601:surgery; D012888:Skull Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D013353:Subdural Effusion / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology / Q000628:therapy; D013524:Surgical Flaps / Q000706:statistics & numerical data; D016896:Treatment Outcome