title: Risk factors for cerebrospinal leak after endoscopic skull base reconstruction with nasoseptal flap.
abstract: OBJECTIVE
  The use of expanded endonasal surgery (EES) in the treatment of skull base neoplasms has increased significantly in recent years. Since 2006, the nasoseptal flap (NSF) has become the workhorse for the closure of skull base defects involving the anterior and central skull base. We hypothesized that defect site impacts the rate of cerebrospinal fluid (CSF) leak following EES.
  
  
  METHODS
  Retrospective cohort study.
  Patients who underwent skull base defect repair using a NSF at the University of California at San Francisco (UCSF) minimally invasive skull base center were retrospectively reviewed. Patient demographics, disease, and defect location and size were recorded along with the presence of a postoperative CSF leak. Data were analyzed using Fisher's exact test.
  
  
  RESULTS
  One hundred and twenty-one patients met inclusion criteria. Ten patients had a NSF failure with CSF leakage, 2 in the anterior skull base (frontal sinus, ethmoid, cribriform, planum), and 8 in the central skull base (sella, clivus) (P = .047). Dural defect size ≥2.0 cm(2) in the central skull base strongly correlated with the risk of flap failure (P = .034).
  
  
  CONCLUSIONS
  This study of endoscopic closure of skull base defects using a NSF demonstrates there is an association between both surgical site and dural defect size with NSF failure. Expanded defects of the sella and clivus have an increased risk of failure and may warrant augmented techniques.
authors.affiliation: School of Medicine, Vanderbilt University, Nashville, Tennessee, USA Department of Otolaryngology-Head and Neck Surgery, University of California at San Francisco, San Francisco, California, USA calvin.l.gruss@vanderbilt.edu.
authors.forename: Calvin L
authors.initials: CL
authors.lastname: Gruss
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University of California at San Francisco, San Francisco, California, USA.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Al Komser
authors.affiliation: Department of Neurosurgery, University of California at San Francisco, San Francisco, California, USA.
authors.forename: Manish K
authors.initials: MK
authors.lastname: Aghi
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University of California at San Francisco, San Francisco, California, USA.
authors.forename: Steven D
authors.initials: SD
authors.lastname: Pletcher
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University of California at San Francisco, San Francisco, California, USA.
authors.forename: Andrew N
authors.initials: AN
authors.lastname: Goldberg
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University of California at San Francisco, San Francisco, California, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: McDermott
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University of California at San Francisco, San Francisco, California, USA.
authors.forename: Ivan H
authors.initials: IH
authors.lastname: El-Sayed
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D065634:Cerebrospinal Fluid Leak; D002559:Cerebrospinal Fluid Rhinorrhea / Q000209:etiology* / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D016001:Confidence Intervals; D004724:Endoscopy / Q000009:adverse effects* / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006085:Graft Survival; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009296:Nasal Cavity / Q000601:surgery*; D011183:Postoperative Complications / Q000453:epidemiology / Q000503:physiopathology; D019651:Plastic Surgery Procedures / Q000009:adverse effects* / Q000379:methods; D012189:Retrospective Studies; D012307:Risk Factors; D019291:Skull Base / Q000473:pathology / Q000601:surgery; D019292:Skull Base Neoplasms / Q000473:pathology / Q000601:surgery*; D013524:Surgical Flaps; D055815:Young Adult
keywords: CSF leak; dural defect; nasoseptal flap; nasoseptal flap failure; skull base defect; skull base reconstruction; skull base surgery