Journal of Neurosurgery: Pediatrics
Tamara D. Simon, Matthew P. Kronman, Kathryn B. Whitlock, Nancy E. Gove, Nicole Mayer-Hamblett, Samuel R. Browd, D. Douglas Cochrane, Richard Holubkov, Abhaya V. Kulkarni, Marcie Langley, David D. Limbrick Jr., Thomas G. Luerssen, W. Jerry Oakes, Jay Riva-Cambrin, Curtis Rozzelle, Chevis Shannon, Mandeep Tamber, John C. Wellons III, William E. Whitehead and John R. W. Kestle
CSF shunt infection requires both surgical and antibiotic treatment. Surgical treatment includes either total shunt removal with external ventricular drain (EVD) placement followed by new shunt insertion, or distal shunt externalization followed by new shunt insertion once the CSF is sterile. Antibiotic treatment includes the administration of intravenous antibiotics. The Hydrocephalus Clinical Research Network (HCRN) registry provides a unique opportunity to understand reinfection following treatment for CSF shunt infection. This study examines the association of surgical and antibiotic decisions in the treatment of first CSF shunt infection with reinfection.
A prospective cohort study of children undergoing treatment for first CSF infection at 7 HCRN hospitals from April 2008 to December 2012 was performed. The HCRN consensus definition was used to define CSF shunt infection and reinfection. The key surgical predictor variable was surgical approach to treatment for CSF shunt infection, and the key antibiotic treatment predictor variable was intravenous antibiotic selection and duration. Cox proportional hazards models were constructed to address the time-varying nature of the characteristics associated with shunt surgeries.
Of 233 children in the HCRN registry with an initial CSF shunt infection during the study period, 38 patients (16%) developed reinfection over a median time of 44 days (interquartile range [IQR] 19–437). The majority of initial CSF shunt infections were treated with total shunt removal and EVD placement (175 patients; 75%). The median time between infection surgeries was 15 days (IQR 10–22). For the subset of 172 infections diagnosed by CSF culture, the mean ± SD duration of antibiotic treatment was 18.7 ± 12.8 days. In all Cox proportional hazards models, neither surgical approach to infection treatment nor overall intravenous antibiotic duration was independently associated with reinfection. The only treatment decision independently associated with decreased infection risk was the use of rifampin. While this finding did not achieve statistical significance, in all 5 Cox proportional hazards models both surgical approach (other than total shunt removal at initial CSF shunt infection) and nonventriculoperitoneal shunt location were consistently associated with a higher hazard of reinfection, while the use of ultrasound was consistently associated with a lower hazard of reinfection.
Neither surgical approach to treatment nor antibiotic duration was associated with reinfection risk. While these findings did not achieve statistical significance, surgical approach other than total removal at initial CSF shunt infection was consistently associated with a higher hazard of reinfection in this study and suggests the feasibility of controlling and standardizing the surgical approach (shunt removal with EVD placement). Considerably more variation and equipoise exists in the duration and selection of intravenous antibiotic treatment. Further consideration should be given to the use of rifampin in the treatment of CSF shunt infection. High-quality studies of the optimal duration of antibiotic treatment are critical to the creation of evidence-based guidelines for CSF shunt infection treatment.
William E. Whitehead, Jay Riva-Cambrin, Abhaya V. Kulkarni, John C. Wellons III, Curtis J. Rozzelle, Mandeep S. Tamber, David D. Limbrick Jr., Samuel R. Browd, Robert P. Naftel, Chevis N. Shannon, Tamara D. Simon, Richard Holubkov, Anna Illner, D. Douglas Cochrane, James M. Drake, Thomas G. Luerssen, W. Jerry Oakes and John R. W. Kestle
Accurate placement of ventricular catheters may result in prolonged shunt survival, but the best target for the hole-bearing segment of the catheter has not been rigorously defined. The goal of the study was to define a target within the ventricle with the lowest risk of shunt failure.
Five catheter placement variables (ventricular catheter tip location, ventricular catheter tip environment, relationship to choroid plexus, catheter tip holes within ventricle, and crosses midline) were defined, assessed for interobserver agreement, and evaluated for their effect on shunt survival in univariate and multivariate analyses. De-identified subjects from the Shunt Design Trial, the Endoscopic Shunt Insertion Trial, and a Hydrocephalus Clinical Research Network study on ultrasound-guided catheter placement were combined (n = 858 subjects, all first-time shunt insertions, all patients < 18 years old). The first postoperative brain imaging study was used to determine ventricular catheter placement for each of the catheter placement variables.
Ventricular catheter tip location, environment, catheter tip holes within the ventricle, and crosses midline all achieved sufficient interobserver agreement (κ > 0.60). In the univariate survival analysis, however, only ventricular catheter tip location was useful in distinguishing a target within the ventricle with a survival advantage (frontal horn; log-rank, p = 0.0015). None of the other catheter placement variables yielded a significant survival advantage unless they were compared with catheter tips completely not in the ventricle. Cox regression analysis was performed, examining ventricular catheter tip location with age, etiology, surgeon, decade of surgery, and catheter entry site (anterior vs posterior). Only age (p < 0.001) and entry site (p = 0.005) were associated with shunt survival; ventricular catheter tip location was not (p = 0.37). Anterior entry site lowered the risk of shunt failure compared with posterior entry site by approximately one-third (HR 0.65, 95% CI 0.51–0.83).
This analysis failed to identify an ideal target within the ventricle for the ventricular catheter tip. Unexpectedly, the choice of an anterior versus posterior catheter entry site was more important in determining shunt survival than the location of the ventricular catheter tip within the ventricle. Entry site may represent a modifiable risk factor for shunt failure, but, due to inherent limitations in study design and previous clinical research on entry site, a randomized controlled trial is necessary before treatment recommendations can be made.
John R. W. Kestle, Richard Holubkov, D. Douglas Cochrane, Abhaya V. Kulkarni, David D. Limbrick Jr., Thomas G. Luerssen, W. Jerry Oakes, Jay Riva-Cambrin, Curtis Rozzelle, Tamara D. Simon, Marion L. Walker, John C. Wellons III, Samuel R. Browd, James M. Drake, Chevis N. Shannon, Mandeep S. Tamber, William E. Whitehead and The Hydrocephalus Clinical Research Network
In a previous report by the same research group (Kestle et al., 2011), compliance with an 11-step protocol was shown to reduce CSF shunt infection at Hydrocephalus Clinical Research Network (HCRN) centers (from 8.7% to 5.7%). Antibiotic-impregnated catheters (AICs) were not part of the protocol but were used off protocol by some surgeons. The authors therefore began using a new protocol that included AICs in an effort to reduce the infection rate further.
The new protocol was implemented at HCRN centers on January 1, 2012, for all shunt procedures (excluding external ventricular drains [EVDs], ventricular reservoirs, and subgaleal shunts). Procedures performed up to September 30, 2013, were included (21 months). Compliance with the protocol and outcome events up to March 30, 2014, were recorded. The definition of infection was unchanged from the authors' previous report.
A total of 1935 procedures were performed on 1670 patients at 8 HCRN centers. The overall infection rate was 6.0% (95% CI 5.1%–7.2%). Procedure-specific infection rates varied (insertion 5.0%, revision 5.4%, insertion after EVD 8.3%, and insertion after treatment of infection 12.6%). Full compliance with the protocol occurred in 77% of procedures. The infection rate was 5.0% after compliant procedures and 8.7% after noncompliant procedures (p = 0.005). The infection rate when using this new protocol (6.0%, 95% CI 5.1%–7.2%) was similar to the infection rate observed using the authors' old protocol (5.7%, 95% CI 4.6%–7.0%).
CSF shunt procedures performed in compliance with a new infection prevention protocol at HCRN centers had a lower infection rate than noncompliant procedures. Implementation of the new protocol (including AICs) was associated with a 6.0% infection rate, similar to the infection rate of 5.7% from the authors' previously reported protocol. Based on the current data, the role of AICs compared with other infection prevention measures is unclear.