title: Risk factors in chronic subdural hematoma: comparison of irrigation with artificial cerebrospinal fluid and normal saline in a cohort analysis.
abstract: BACKGROUND
  Chronic subdural hematoma (CSDH) is known to have a substantial recurrence rate. Artificial cerebrospinal fluid (ACF) is an effective irrigation solution in general open craniotomy and endoneurosurgery, but no evidence of its use in burr-hole surgery exists.
  
  
  OBJECTIVE
  To identify the potential of ACF irrigation to prevent CSDH recurrence. More specifically, to investigate the perioperative and intraoperative prognostic factors, and to identify controllable ones.
  
  
  METHODS
  To examine various prognostic factors, 120 consecutive patients with unilateral CSDH treated with burr-hole drainage between September 2007 and March 2013 were analyzed. Intraoperative irrigation was performed with one of two irrigation solutions: normal saline (NS; n = 60) or ACF (n = 60). All patients were followed-up for at least 6 months postoperatively. We also examined the morphological alternations of the hematoma outer membranes after incubation with different solutions.
  
  
  RESULTS
  Eleven patients (9.2%) had recurrence. Nine patients (15%) required additional surgery in the NS group, whereas only 2 patients (3.3%) in the ACF group required additional surgery. Among preoperative and intraoperative data, age (<80 years old, P = .044), thrombocyte (>22.0, P = .037), laterality (right, P = .03), and irrigation solution (ACF, P = .027) were related to smaller recurrence rates by log-rank tests. Only the type of irrigation solution used significantly correlated with recurrence in favor of ACF in both Cox proportional hazards (relative hazard: 0.20, 95% confidence interval (CI): 0.04-0.99; P = .049) and logistic regression models (odds ratio, 0.17, 95% CI: 0.03-0.92; P = .04) using these factors. Histological examinations of the hematoma membranes showed that the membranes incubated with NS were loose and infiltrated by inflammatory cells compared with those incubated with ACF.
  
  
  CONCLUSIONS
  Irrigation with ACF decreased the rate of CSDH recurrence.
authors.affiliation: Department of Neurosurgery, Chiba Cardiovascular Center, Tsurumai, Ichihara, Japan; Department of Neurological Surgery, Chiba University Graduate School of Medicine, Inohana, Chiba, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Adachi
authors.affiliation: Department of Neurosurgery, Chiba Cardiovascular Center, Tsurumai, Ichihara, Japan; Department of Neurological Surgery, Chiba University Graduate School of Medicine, Inohana, Chiba, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Higuchi
authors.affiliation: Department of Neurosurgery, Chiba Cardiovascular Center, Tsurumai, Ichihara, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Fujikawa
authors.affiliation: Department of Neurosurgery, Chiba Cardiovascular Center, Tsurumai, Ichihara, Japan.
authors.forename: Toshio
authors.initials: T
authors.lastname: Machida
authors.affiliation: Department of Clinical Laboratory, Chiba Cardiovascular Center, Tsurumai, Ichihara, Japan; Department of Molecular Diagnosis, Chiba University Graduate School of Medicine, Inohana, Chiba, Japan.
authors.forename: Shigeo
authors.initials: S
authors.lastname: Sueyoshi
authors.affiliation: Department of Molecular and Tumor Pathology, Chiba University Graduate School of Medicine, Inohana, Chiba, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Harigaya
authors.affiliation: Department of Neurosurgery, Chiba Cardiovascular Center, Tsurumai, Ichihara, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Ono
authors.affiliation: Department of Neurological Surgery, Chiba University Graduate School of Medicine, Inohana, Chiba, Japan.
authors.forename: Naokatsu
authors.initials: N
authors.lastname: Saeki
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002555:Cerebrospinal Fluid / Q000737:chemistry*; D002908:Chronic Disease; D015331:Cohort Studies; D005260:Female; D020200:Hematoma, Subdural, Chronic / Q000473:pathology / Q000601:surgery / Q000628:therapy*; D006801:Humans; D008297:Male; D008566:Membranes / Q000601:surgery; D015999:Multivariate Analysis; D009493:Neurosurgery; D012008:Recurrence; D012307:Risk Factors; D012965:Sodium Chloride / Q000627:therapeutic use*; D012996:Solutions; D007507:Therapeutic Irrigation
chemical_list: D012996:Solutions; D012965:Sodium Chloride
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