title: Transoral and transnasal odontoidectomy complications: A systematic review and meta-analysis.
abstract: OBJECTIVE
  The craniovertebral junction (CVJ) is a complex region of the spine with unique anatomical and functional relationships. To alleviate symptoms associated with pathological processes involving the odontoid process, decompression is often required, including odontoidectomy. Accurate knowledge of the complication rates following the transoral and transnasal techniques is essential for both patients and surgeons.
  
  
  METHODS
  We conducted MEDLINE, Scopus and Web of Science database searches for studies reporting complications associated with the transoral and transnasal techniques for odontoidectomy. Case series presenting data for less than three patients were excluded. Rates of complication and clinical outcomes were calculated and subsequently analyzed using a fixed-effects model to assess statistical significance.
  
  
  RESULTS
  Of 1288 articles retrieved from MEDLINE, Scopus, and Web of Science, twenty-six met inclusion criteria. Transoral and transnasal procedures resulted in the following respective complication rates: arterial injury 1.9% and 0.0%, intraoperative CSF leak 0.3% and 30.0%, postoperative CSF leak 0.8% and 5.2%, 30-day mortality 2.9% and 4.4%, medical complications 13.9% and 28.6%, meningitis 1.0% and 4.0%, pharyngeal wound dehiscence 1.7% (transnasal not reported), pneumonia 10.3% (transnasal not reported), prolonged or re-intubation 5.6% and 6.0%, reoperation 2.5% and 5.1%, sepsis 1.9% and 7.7%, tracheostomy 10.8% and 3.4%, velopharyngeal insufficiency 3.3% and 6.4% and wound infection 3.3% and 1.9%. None of these differences were statistically significant, except for postoperative tracheostomy, which was significantly higher after transoral odontoidectomy 8.4% (95% CI 4.9% -11.9%) compared to transnasal odontoidectomy 0.8% (95% CI -1.0% -2.9%). Neurologic outcome was improved in 90.0% and worse in 0.9% of patients after transoral compared to 94.0% and 0.0% after transnasal odontoidectomy (p=0.30).
  
  
  CONCLUSIONS
  This work presents a systematic review of complications reported for transoral or transnasal odontoidectomy across a heterogeneous group of surgeons and patients. Due to inconsistent reporting, statistical significance was only achieved for postoperative tracheostomy, which was significantly higher in the transoral group. This investigation sets the framework for further discussions regarding odontoidectomy approach options and their associated complications during the informed consent process.
authors.affiliation: Rosa Ella Burkhardt Brain Tumor and Neuro-Oncology Center, Neurological Institute, Cleveland Clinic, Cleveland, OH, United States.
authors.forename: Michael F
authors.initials: MF
authors.lastname: Shriver
authors.affiliation: Rosa Ella Burkhardt Brain Tumor and Neuro-Oncology Center, Neurological Institute, Cleveland Clinic, Cleveland, OH, United States.
authors.forename: Varun R
authors.initials: VR
authors.lastname: Kshettry
authors.affiliation: Rosa Ella Burkhardt Brain Tumor and Neuro-Oncology Center, Neurological Institute, Cleveland Clinic, Cleveland, OH, United States; Section of Rhinology, Sinus, and Skull Base Surgery, Head and Neck Institute, Cleveland Clinic, Cleveland, OH, United States; Minimally Invasive Cranial Base and Pituitary Surgery Program, Cleveland Clinic, Cleveland, OH, United States.
authors.forename: Raj
authors.initials: R
authors.lastname: Sindwani
authors.affiliation: Rosa Ella Burkhardt Brain Tumor and Neuro-Oncology Center, Neurological Institute, Cleveland Clinic, Cleveland, OH, United States; Section of Rhinology, Sinus, and Skull Base Surgery, Head and Neck Institute, Cleveland Clinic, Cleveland, OH, United States; Minimally Invasive Cranial Base and Pituitary Surgery Program, Cleveland Clinic, Cleveland, OH, United States.
authors.forename: Troy
authors.initials: T
authors.lastname: Woodard
authors.affiliation: Center for Spine Health, Neurological Institute, Cleveland Clinic, Cleveland, OH, United States.
authors.forename: Edward C
authors.initials: EC
authors.lastname: Benzel
authors.affiliation: Rosa Ella Burkhardt Brain Tumor and Neuro-Oncology Center, Neurological Institute, Cleveland Clinic, Cleveland, OH, United States; Section of Rhinology, Sinus, and Skull Base Surgery, Head and Neck Institute, Cleveland Clinic, Cleveland, OH, United States; Minimally Invasive Cranial Base and Pituitary Surgery Program, Cleveland Clinic, Cleveland, OH, United States. Electronic address: recinop@ccf.org.
authors.forename: Pablo F
authors.initials: PF
authors.lastname: Recinos
mesh_terms: D006801:Humans; D007431:Intraoperative Complications / Q000209:etiology*; D009055:Mouth / Q000601:surgery*; D057605:Natural Orifice Endoscopic Surgery / Q000009:adverse effects*; D009809:Odontoid Process / Q000601:surgery*; D011183:Postoperative Complications / Q000209:etiology*
keywords: Basilar impression; Basilar invagination; Craniovertebral junction; Endonasal; Endoscopic; Velopharyngeal insufficiency