title: A case-comparison study of the subdural evacuating port system in treating chronic subdural hematomas.
abstract: OBJECTIVE
  The Subdural Evacuating Port System (SEPS) was recently introduced as a novel method of treating chronic subdural hematomas (SDHs). This system is a variation of the existing twist-drill craniostomy methods for treating chronic SDH. Compared with craniotomy or bur hole treatment of chronic SDH, this system offers the possibility of treatment at bedside without general anesthesia. In comparison with existing twist-drill methods, the system theoretically offers the advantage of a hermetically closed system that can evacuate a hematoma without an intracranial catheter.
  
  
  METHODS
  The authors performed a case-control study of all chronic SDHs treated at a single institution over a 5-year period and compared the efficacy and safety of the SEPS to bur hole evacuation. Patients were matched for age, injury mechanism, medical comorbidities, use of anticoagulation, and radiographic appearance of the SDH. The primary outcome of interest was the recurrence rate in each group, which was evaluated by radiographic evidence as well as the number of patients requiring a second procedure. Secondary outcomes examined were mortality, infection, acute hematoma formation, seizure, length of hospital stay, length of intensive care unit stay, and discharge location.
  
  
  RESULTS
  The authors found that there were no appreciable differences in symptoms on presentation, existing comorbidities, home medications, or laboratory values between the treatment groups. The average Hounsfield units of preoperative CT scanning was similar in both groups. Radiographic recurrence was statistically similar between the SEPS group (25.9%) and the bur hole group (18.5%; p = 0.37). Although there was a trend toward higher reoperation rates in the SEPS group, the need for a subsequent procedure was also statistically similar between the SEPS group (25.9%) and the bur hole group (14.8%; p = 0.25). The mortality rate was not significantly different between the SEPS group (9.5%) and the bur hole group (4.8%; p = 0.50). The SEPS procedure provided a mean reduction in SDH thickness of 27.3% compared with 37.9% with bur hole (p = 0.05) when comparing the preoperative CT scan with the first postoperative CT scan. The percentage of reduction in SDH thickness when comparing the preoperative CT scan with the most recent postoperative CT scan was 40.5% in the SEPS group and 45.4% in the bur hole group (p = 0.31).
  
  
  CONCLUSIONS
  The SEPS offers an alternative type of twist-drill craniostomy for the treatment of chronic SDH with a trend toward higher recurrence in our experience. The efficacy and safety of SEPS is similar to that of other twist-drill methods reported in the literature. In the authors' experience, the efficacy of this treatment as measured by radiographic worsening or the need for a subsequent procedure is statistically similar to that of bur hole treatment. There was no difference in mortality or other adverse outcomes associated with SEPS.
authors.affiliation: Division of Neurosurgery, University of Vermont, Burlington, Vermont 05401, USA. anand.rughani@vtmednet.org
authors.forename: Anand I
authors.initials: AI
authors.lastname: Rughani
authors.forename: Chih
authors.initials: C
authors.lastname: Lin
authors.forename: Travis M
authors.initials: TM
authors.lastname: Dumont
authors.forename: Paul L
authors.initials: PL
authors.lastname: Penar
authors.forename: Michael A
authors.initials: MA
authors.lastname: Horgan
authors.forename: Bruce I
authors.initials: BI
authors.lastname: Tranmer
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D015897:Comorbidity; D003399:Craniotomy / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods; D004322:Drainage / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods; D020200:Hematoma, Subdural, Chronic / Q000188:drug therapy / Q000453:epidemiology / Q000601:surgery*; D006801:Humans; D019635:Neurosurgical Procedures / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods; D012008:Recurrence; D012449:Safety; D016896:Treatment Outcome