title: The clinical significance and optimal timing of postoperative computed tomography following cranial surgery.
abstract: OBJECTIVE
  This study was conducted to evaluate the value of postoperative CT scans in determining the probability of return to the operating room (OR) and the optimal time to obtain such scans to determine the effects of surgery.
  
  
  METHODS
  Between January and December 2006 (12 months), all postoperative head CT scans obtained for 3 individual surgeons were reviewed. Scans were divided into 3 groups, which were determined by the preference of each surgeon: Group A (early scans-scheduled between 0 and 7 hours); Group B (delayed scans-scheduled between 8 and 24 hours); and Group C (urgent scans-ordered because of a new neurological deficit). The initial scans were reviewed and analyzed in 2 different fashions. The first was to analyze the efficacy of the scans in predicting return to the OR. The second was to determine the optimal time for obtaining a scan. The second analysis was a review of serial postoperative scans for expected versus unexpected findings and changes in the acuity of these findings over time.
  
  
  RESULTS
  In 251 (74%) of 338 cases, the patients had postoperative head CT scans within 24 hours of surgery. Analysis 1 determined the percent of patients returning to the OR for emergency treatment based on postoperative scans: Group A (early)-133 patients, with 0% returning to the OR; Group B (delayed)-108 patients, with 0% returning to the OR; and Group C (urgent)-10 patients, with 30% returning to the OR (p < 0.05). Analysis 2 determined the optimal timing of postoperative scans and changes in scan acuity: Group A (early scan) had an 11% incidence of change in acuity on subsequent scans. Group B (delayed scan) had a 3% incidence of change in acuity on follow-up scans (p < 0.05).
  
  
  CONCLUSIONS
  Routine postoperative scans at 0-7 hours or at 8-24 hours are not predictive of return to the OR, whereas patients with a new neurological deficit in the postoperative period have a 30% chance of emergency reoperation based on CT scans. In addition, early postoperative scans (0-7 hours) fail to predict CT changes, which might evolve over time and may influence postoperative medical management.
authors.affiliation: Department of Neurological Surgery, Loyola University Medical Center, Maywood, Illinois 60153, USA.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Khaldi
authors.forename: Vikram C
authors.initials: VC
authors.lastname: Prabhu
authors.forename: Douglas E
authors.initials: DE
authors.lastname: Anderson
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Origitano
mesh_terms: D001921:Brain / Q000000981:diagnostic imaging* / Q000601:surgery; D006801:Humans; D019635:Neurosurgical Procedures / Q000379:methods*; D011184:Postoperative Period; D013997:Time Factors; D014057:Tomography, X-Ray Computed