title: Delayed extrusion of hydroxyapatite cement after transpetrosal reconstruction.
abstract: OBJECTIVE
  Use of hydroxyapatite cement has been advocated for closure of transpetrosal defects to decrease the incidence of cerebrospinal fluid leaks. We previously identified delayed extrusion of this cement as a significant complication associated with this closure technique and now update our long-term experience.
  
  
  METHODS
  In our retrospective review, we identified 1231 patients who underwent transpetrosal procedures by our multidisciplinary cranial base team between 1984 and 2005. Of the subgroup of 177 patients who had hydroxyapatite cement used during the closure of the procedure, 13 patients (7.3%) experienced delayed extrusion of hydroxyapatite cement.
  
  
  RESULTS
  Extrusion occurred in 3 patients within 12 months and in 10 patients within 68 to 140 months. Twelve patients presented with draining fistulae and concomitant Staphylococcus aureus infection; 1 patient presented asymptomatically with a large temporal lobe abscess identified on surveillance magnetic resonance imaging. All 13 patients underwent reoperation, including 1 who underwent a second procedure.
  
  
  CONCLUSIONS
  Delayed extrusion of hydroxyapatite cement resulted in significant morbidity to our patients and often presented in an indolent manner. We recommend serial examination and imaging studies in patients who have had transpetrosal closures with hydroxyapatite cement. Because of the complication rates associated with hydroxyapatite cement, we have discontinued its use.
authors.affiliation: Department of Neurosurgery, University of Cincinnati Neuroscience Institute and College of Medicine, Cincinnati, Ohio 45267-0515, USA.
authors.forename: Robert G
authors.initials: RG
authors.lastname: Kerr
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Hearst
authors.forename: Ravi N
authors.initials: RN
authors.lastname: Samy
authors.forename: Harry R
authors.initials: HR
authors.lastname: van Loveren
authors.forename: John M
authors.initials: JM
authors.lastname: Tew
authors.forename: Myles L
authors.initials: ML
authors.lastname: Pensak
authors.forename: Philip V
authors.initials: PV
authors.lastname: Theodosopoulos
mesh_terms: D000328:Adult; D000368:Aged; D001843:Bone Cements / Q000009:adverse effects* / Q000627:therapeutic use; D017886:Durapatite / Q000008:administration & dosage / Q000009:adverse effects*; D005119:Extravasation of Diagnostic and Therapeutic Materials / Q000175:diagnosis* / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010579:Petrous Bone / Q000601:surgery*; D019651:Plastic Surgery Procedures / Q000009:adverse effects*; D012189:Retrospective Studies; D013203:Staphylococcal Infections / Q000175:diagnosis / Q000209:etiology*; D055815:Young Adult
chemical_list: D001843:Bone Cements; D017886:Durapatite