title: Organized subdural hematoma with thick membrane in chronic  subdural hematoma.
abstract: BACKGROUND
  Chronic subdural hematoma (CSDH) may occasionally contain organized hematoma which can lead to recurrence and other complications after surgery. There is no exact study and data about OHTMF in Nepal so far. The main objective of this study is to study its prevalence and complications.
  
  
  METHODS
  This is a multicentric retrospective analytical study being carried out at Norvic International Hospital and Annapurna Neurological Institute. We retrospectively analyzed one hundred cases of CSDH between early 2006 to 2010 August. We focused our study mainly on OHTMF.
  
  
  RESULTS
  Of 100 cases, majority of the patients were male ranging from 4 to 85 years of age. Bilateral subdural hematoma was found in about 9% of cases. Majority of cases were treated in usual fashion with single burr hole and drain. OHTMF was found in 3 cases (3%) for which craniotomy with radical membranectomy was performed. In 2 cases membrane formation was noticed during surgery, craniotomy with total membranectomy was performed immediately. In one case there was recurrence of CSDH within 10 days of single burr hole evacuation. Craniotomy with membranectomy was performed in 2nd surgery. There was no recurrence after membranectomy. One case developed seizure post operatively.
  
  
  CONCLUSIONS
  OHTMF is one of the important causes of CSDH recurrence. It has to be treated radically. Different hypthotheses have been postulated regarding thick membrane formation in CSDH. We have tried to discuss these hypotheses.
authors.affiliation: Department of Neurosurgery, Norvic International Hospital, Kathmandu. prabinshrestha@hotmail.com
authors.forename: P
authors.initials: P
authors.lastname: Shrestha
authors.forename: B
authors.initials: B
authors.lastname: Pant
authors.forename: P
authors.initials: P
authors.lastname: Shrestha
authors.forename: P
authors.initials: P
authors.lastname: Rajbhandari
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D003399:Craniotomy; D004322:Drainage; D005260:Female; D020200:Hematoma, Subdural, Chronic / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009390:Nepal; D012008:Recurrence; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D055815:Young Adult