title: Double-layer appearance after evacuation of a chronic subdural hematoma.
abstract: OBJECTIVE
  To investigate the reason for and the course of the double-layer appearance in the postoperative computed tomographies (CTs) of chronic subdural hematoma (CSDHs).
  
  
  METHODS
  We reviewed CSDH cases that were operated on during the last 3 years, between January 2008 and December 2010. We checked the preoperative, early postoperative, and late postoperative CTs of these patients. We investigated the relationship between the formation of a double-layer appearance and the prognoses and demographic characteristics of the patients.
  
  
  RESULTS
  Our database included 119 cases. A double-layer appearance was found in the postoperative CTs of 34 cases. The mean age of double-layer cases was older (72.5 ± 12.1) than that of the remaining 85 cases (63.1 ± 17.8). We did not find any relationship between the double-layer appearance and the reoperation/recurrence/death rates.
  
  
  CONCLUSIONS
  The double-layer appearance after evacuation of a CSDH might be caused by enlargement of the subarachnoid space and is not related to the presence of any residual hematoma. This appearance is not considered as a reason for reoperation.
authors.affiliation: Department of Neurosurgery, İzmir Atatürk Research and Training Hospital , İzmir , Turkey.
authors.forename: Hasan Kamil
authors.initials: HK
authors.lastname: Sucu
authors.forename: Ömer
authors.initials: Ö
authors.lastname: Akar
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003399:Craniotomy / Q000009:adverse effects / Q000379:methods; D004322:Drainage / Q000009:adverse effects / Q000379:methods; D015600:Glasgow Coma Scale; D020200:Hematoma, Subdural, Chronic / Q000000981:diagnostic imaging / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000009:adverse effects* / Q000379:methods; D011183:Postoperative Complications / Q000000981:diagnostic imaging*; D011859:Radiography; D012086:Reoperation / Q000379:methods; D013346:Subarachnoid Space / Q000000981:diagnostic imaging*; D016896:Treatment Outcome