title: Is the recurrence rate of chronic subdural hematomas dependent on the duration of drainage?
abstract: OBJECTIVE
  Chronic subdural hematoma (CSDH) is the most frequent type of intracranial hemorrhage which especially affects the elderly. Various surgical techniques have been reported for CSDH treatment; optimal treatment methods are still controversial. In this study, the effects of long drainage durations on results and recurrences were investigated in patients on whom closed system drainage with burr hole craniotomy was applied due to CSDH.
  
  
  METHODS
  90 patients with 105 CSDH were operated between 2008 and 2016. Patients were divided into two groups based on the duration of drainage. Group A (n = 40) was determined as 2-4 days of closed-system drainage, while Group B (n = 50) was recorded as 5-7 days of closed-system drainage. Recurrence was defined as accumulation of blood in the operation area and recurrence of symptoms within the monitoring period of six months.
  
  
  RESULTS
  Recurrence was observed in 7 (15.6) of the Group A patients and 2 (3.3%) of the Group B patients. There was a statistically significant difference between groups in terms of recurrence rate (p = 0.04). Postoperative thickness of hematoma was measured in the first month follow-up computerized tomography. There was a statistically significant difference between groups in terms of postoperative thickness of residual hematoma (p = 0.05).
  
  
  CONCLUSIONS
  2-4 days of closed system drainage following burr hole craniotomy is an effective and reliable choice of treatment in CSDH. Nevertheless, increasing the duration of drainage to 5-7 days provided better results without increasing the risk of complication.
authors.affiliation: a Faculty of Medicine, Department of Neurosurgery , Bülent Ecevit University , Zonguldak , Turkey.
authors.forename: Aydemir
authors.initials: A
authors.lastname: Kale
authors.affiliation: b Faculty of Medicine, Department of Radiology , Bülent Ecevit University , Zonguldak , Turkey.
authors.forename: İbrahim İlker
authors.initials: İİ
authors.lastname: Öz
authors.affiliation: a Faculty of Medicine, Department of Neurosurgery , Bülent Ecevit University , Zonguldak , Turkey.
authors.forename: Eren Görkem
authors.initials: EG
authors.lastname: Gün
authors.affiliation: a Faculty of Medicine, Department of Neurosurgery , Bülent Ecevit University , Zonguldak , Turkey.
authors.forename: Murat
authors.initials: M
authors.lastname: Kalaycı
authors.affiliation: a Faculty of Medicine, Department of Neurosurgery , Bülent Ecevit University , Zonguldak , Turkey.
authors.forename: Şanser
authors.initials: Ş
authors.lastname: Gül
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003399:Craniotomy / Q000009:adverse effects*; D004322:Drainage / Q000009:adverse effects*; D005260:Female; D020200:Hematoma, Subdural, Chronic / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology / Q000209:etiology; D012008:Recurrence; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D014207:Trephining / Q000009:adverse effects*; D055815:Young Adult
keywords: Chronic subdural hematoma; burr hole craniotomy; closed-system drainage; duration; recurrence