title: Sonication of catheter tips for improved detection of microorganisms on external ventricular drains and ventriculo-peritoneal shunts.
abstract: The diagnosis of infections involving internal or external neurosurgical drainage devices is challenging, and to our knowledge no single reliable microbiological test exists. We used sonication to study bacterial colonization in 14 explanted external ventricular drains (EVD) and 13 ventriculo-peritoneal shunt (VPS) devices. This technique dislodges biofilm bacteria from the surface of implanted materials before culture. Removed devices were sonicated in saline (40 kHz, 1 minute, 0.25 W/cm(2)), the resulting fluid was cultured aerobically and anaerobically at 37°C, and bacterial growth was counted. Ventricular cerebrospinal fluid (CSF) was cultured separately. In the EVD group, sonication cultures grew significantly more bacteria (64%, 9/14) than cultures of aspirated ventricular CSF (14%, 2/14). In the VPS group the difference was not significant. Positive sonication cultures of EVD catheters yielded a median of >100 colony forming units (CFU) (range, 60-800). For positive sonication cultures of VPS, the median was 1000 CFU (range, 20-100,000). All patients with bacteria in their CSF also had positive sonication cultures from the removed device. Of the five patients with sterile or presumably contaminated CSF cultures but positive sonication cultures of removed shunts, one became afebrile after removal of the EVD, two developed meningitis and two remained asymptomatic. Sonication culture of EVD appears to improve the microbiological assessment of device-related infection and it corroborates with CSF cultures of revision surgery for VPS. Sonication of the removed EVD tip may raise awareness for the onset of meningitis.
authors: Department of Neurosurgery, University Hospital Basel, Spitalstrasse 21, 4031 Basel, Switzerland. Electronic address: gregoryjost@gmx.ch.
authors: Gregory F
authors: GF
authors: Jost
authors: Department of Neurosurgery, University Hospital Basel, Spitalstrasse 21, 4031 Basel, Switzerland.
authors: Morten
authors: M
authors: Wasner
authors: Department of Neurosurgery, University Hospital Basel, Spitalstrasse 21, 4031 Basel, Switzerland.
authors: Ethan
authors: E
authors: Taub
authors: Septic Surgery Unit, Department of Surgery and Anesthesiology, University Hospital Lausanne, Lausanne, Switzerland.
authors: Laura
authors: L
authors: Walti
authors: Department of Neurosurgery, University Hospital Basel, Spitalstrasse 21, 4031 Basel, Switzerland.
authors: Luigi
authors: L
authors: Mariani
authors: Charité, University Medicine, Free and Humboldt-University of Berlin, Berlin, Germany.
authors: Andrej
authors: A
authors: Trampuz
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001419:Bacteria / Q000302:isolation & purification; D018441:Biofilms; D055499:Catheter-Related Infections / Q000175:diagnosis*; D057785:Catheters; D002555:Cerebrospinal Fluid / Q000382:microbiology*; D002557:Cerebrospinal Fluid Shunts; D004322:Drainage / Q000295:instrumentation; D005260:Female; D006801:Humans; D008297:Male; D008581:Meningitis / Q000175:diagnosis; D008875:Middle Aged; D013010:Sonication / Q000379:methods*; D017287:Ventriculoperitoneal Shunt; D055815:Young Adult
keywords: External ventricular drain; Infection; Meningitis; Shunt; Sonication