Diffusion tensor imaging and ventricle volume quantification in patients with chronic shunt-treated hydrocephalus

J Neurosurg 129:1611–1622, 2018

The object of this study was to use diffusion tensor imaging (DTI) and tract-based spatial statistics (TBSS) to characterize the long-term effects of hydrocephalus and shunting on white matter integrity and to investigate the relationship of ventricular size and alterations in white matter integrity with headache and quality-of-life outcome measures.

METHODS Patients with shunt-treated hydrocephalus and age- and sex-matched healthy controls were recruited into the study and underwent anatomical and DTI imaging on a 3-T MRI scanner. All patients were clinically stable, had undergone CSF shunt placement before 2 years of age, and had a documented history of complaints of headaches. Outcome was scored based on the Headache Disability Inventory and the Hydrocephalus Outcome Questionnaire. Fractional anisotropy (FA) and other DTI-based measures (axial, radial, and mean diffusivity; AD, RD, and MD, respectively) were extracted in the corpus callosum and internal capsule with manual region-of-interest delineation and in other regions with TBSS. Paired t-tests, corrected with a 5% false discovery rate, were used to identify regions with significant differences between patients and controls. Within the patient group, linear regression models were used to investigate the relationship between FA or ventricular volume and outcome, as well as the effect of shunt-related covariates.

RESULTS Twenty-one hydrocephalus patients and 21 matched controls completed the study, and their data were used in the final analysis. The authors found significantly lower FA for patients than for controls in 20 of the 48 regions, mostly posterior white matter structures, in periventricular as well as more distal tracts. Of these 20 regions, 17 demonstrated increased RD, while only 5 showed increased MD and 3 showed decreased AD. No areas of increased FA were observed. Higher FA in specific periventricular white matter tracts, tending toward FA in controls, was associated with increased ventricular size, as well as improved clinical outcome.

CONCLUSIONS The study shows that TBSS-based DTI is a sensitive technique for elucidating changes in white matter structures due to hydrocephalus and chronic CSF shunting and provides preliminary evidence that DTI may be a valuable tool for tailoring shunt procedures to monitor ventricular size following shunting and achieve optimal outcome, as well as for guiding the development of alternate therapies for hydrocephalus.

 

The economic impact of ventriculoperitoneal shunt failure

J Neurosurg Pediatrics 8:539–599, 2011.DOI: 10.3171/2011.9.PEDS11192

Detailed costs to individuals with hydrocephalus and their families as well as to third-party payers have not been previously described. The purpose of this study was to determine the primary caregiver out-of-pocket expenses and the third-party payer reimbursement rate associated with a shunt failure episode.

Methods. A retrospective study of children born between 2000 and 2005 who underwent initial ventriculoperitoneal (VP) shunt placement and who subsequently experienced a shunt failure requiring surgical intervention within 2 years of their initial shunt placement was conducted. Institutional reimbursement and demographic data from Children’s Hospital of Alabama (CHA) were augmented with a caregiver survey of any out-of pocket expenses encountered during the shunt failure episode. Institutional reimbursements and caregiver out-of-pocket expenses were then combined to provide the cost for a shunt failure episode at CHA.

Results. For shunt failures, the median reimbursement total was $5008 (interquartile range [IQR] $2068– $17,984), the median caregiver out-of-pocket expenses was $419 (IQR $251–$1112), and the median total cost was $5411 (IQR $2428–$18,582). Private insurance reimbursed at a median rate of $5074 (IQR $2170–$14,852) compared with public insurance, which reimbursed at a median rate of $4800 (IQR $1876–$19,395). Caregivers with private insurance reported a median $963 (IQR $322–$1741) for out-of-pocket expenses, whereas caregivers with public insurance reported a median $391 (IQR $241–$554) for out-of-pocket expenses (p = 0.017).

Conclusions. This study confirmed that private insurance reimbursed at a higher rate, and that although patients had a shorter length of stay as compared with those with public insurance, their out-of-pocket expenses associated with a shunt failure episode were greater. However, it could not be determined if the significant difference in outof- pocket expenses between those with private and those with public insurance was due directly to the cost of shunt failure. This model does not take into consideration community resources and services available to those with public insurance. These resources and services could offset the out-of-pocket burden, and therefore should be considered in future cost models.