Tag: CSF diversion

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Microcirculatory Impairment and Cerebral Injury in Hydrocephalus and the Effects of Cerebrospinal Fluid Diversion

Neurosurgery 95:469–479, 2024

Hydrocephalus is characterized by progressive enlargement of cerebral ventricles, resulting in impaired microvasculature and cerebral hypoperfusion. This study aimed to demonstrate the microvascular changes in hydrocephalic rats and the effects of cerebrospinal fluid (CSF) release on cerebral blood flow (CBF).

METHODS: On postnatal day 21 (P21), male Wistar rats were intracisternally injected with either a kaolin suspension or saline. On P47, Evan’s ratio (ER) was measured using MRI. On P49, the arteriolar diameter and vascular density of the pia were quantified using a capillary video microscope. The CBF was measured using laser Doppler flowmetry. The expressions of NeuN and glial fibrillary acidic protein determined by immunochemical staining were correlated with the ER. The CBF and rotarod test performance were recorded before and after CSF release. The expressions of 4-hydroxynonenal (4-HNE) and c-caspase-3 were studied on P56.

RESULTS: Ventriculomegaly was induced to varying degrees, resulting in the stretching and abnormal narrowing of pial arterioles, which regressed with increasing ER. Quantitative analysis revealed significant decreases in the arteriolar diameter and vascular density in the hydrocephalic group compared with those in the control group. In addition, the CBF in the hydrocephalic group decreased to 30%–50% of that in the control group. In hydrocephalus, the neurons appear distorted, and the expression of 4-HNE and reactive astrogliosis increase in the cortex. After CSF was released, improvements in the CBF and rotarod test performance were inversely associated with the ER. In addition, the levels of 4-HNE and c-caspase-3 were further elevated.

CONCLUSION: Rapid ventricular dilatation is associated with severe microvascular distortion, vascular regression, cortical hypoperfusion, and cellular changes that impair the recovery of CBF and motor function after CSF release. Moreover, CSF release may induce reperfusion injury. This pathophysiology should be taken into account when treating hydrocephalus.

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The Role of Prophylactic Intraventricular Antibiotics in Reducing the Incidence of Infection and Revision Surgery in Pediatric Patients Undergoing Shunt Placement

Neurosurgery 88(2)2021: 301–305

Ventriculoperitoneal shunt placement remains the primary treatment modality for children with hydrocephalus. However, morbidity and revision surgery secondary to infection remains high, even while using antibiotic-impregnated shunts.

OBJECTIVE: To determine whether intraoperative injection of antibiotics is independently associated with reduced rates of infection and revision surgery in children undergoing shunt placement.

METHODS: This is an analysis of a prospectively collected, multicenter, shunt-specific neurosurgical registry consisting of data from over 100 hospitals collected between 2016 and 2017. All patients under 18 yr of age undergoing first-time shunt placement for the definitive treatment of hydrocephaluswere included. The primary exposure of interest was injection of intraventricular antibiotics into the shunt catheter following shunt placement and prior to closure. The use of additional surgical adjuncts, such as antibiotic-impregnated shunts, stereotactic guidance, and endoscopy was collected. The primary outcome metric was the need for additional intervention because of an infection.

RESULTS: A total of 2007 pediatric patients undergoing shunt placement for hydrocephalus were identified. Postoperatively, 97 (4.8%) patients had additional intervention secondary to infection. In a multivariable regression model controlling for patient characteristics, etiology of hydrocephalus, prior temporizing measures, and placement of an antibiotic-impregnated shunt, injection of intraventricular antibiotics was associated with a significant reduction in postoperative infections (odds ratio = 0.29, 95% CI: 0.04-0.89, P=.038). Of those receiving intraventricular antibiotics, only 2 (0.38%)went on to undergo re-intervention due to infection.

CONCLUSION: These data suggest that for this select group of patients, use of intraventricular antibiotics was associated with decreased rates of re-intervention secondary to infection.

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Treatment Options for Hydrocephalus Following Foramen Magnum Decompression for Chiari I Malformation: A Multicenter Study

Neurosurgery 86(4): 500-508, 2020

New-onset hydrocephalus following foramen magnum decompression (FMD) for Chiari I malformation (CM-I) is rare; its natural history and pathophysiology are poorly understood.

OBJECTIVE: To describe a series of patients who developed hydrocephalus following FMD for CM-I, provide possible explanations of this phenomenon, and outline treatment options.

METHODS: Out of patients undergoing FMD for CM-I from 6 different tertiary centers, we evaluated patients presenting with new-onset hydrocephalus following FMD. The retrospectively collected data included demographics, clinical, and radiological findings of the CM-I and hydrocephalus patients. Time from FMD and hydrocephalus onset, treatment, and surgical techniques were assessed.

RESULTS: Of 549 patients who underwent FMD for CM-I, 28 (5.1%) subsequently developed hydrocephalus (18 females, 10 males), with a mean age of 11.7 ± 11.9 yr (range 6 mo to 52 yr). Hydrocephalus occurred on average 2.2 ± 2.6 mo after FMD (range 1 wk to 8 mo). Four patients did not have a violation of the arachnoid during the FMD surgery. Main presenting symptoms of hydrocephalus were headaches (17, 41%), vomiting (10, 24.4%), and cerebrospinal fluid (CSF) leak or pseudomeningocele (7, 17%). Overall, 23 patients (82.1%) underwent CSF shunting, 1 patient (3.5%) had an endoscopic third ventriculostomy, 3 patients (10.7%) temporary CSF diversion only, and 1 patient (3.5%) was treated with acetazolamide.

CONCLUSION:Hydrocephalus following FMDforCM-I is uncommon,but important. Based on our series and literature review, its incidence is about 5% to 7% and most likely will require further surgery. Shunting appears to be the favored treatment option.

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Glaucoma in patients with shunt-treated normal pressure hydrocephalus

J Neurosurg 129:1078–1084, 2018

Changes in the pressure gradient between intraocular and intracranial compartments at the lamina cribrosa level are a possible explanation of normal tension glaucoma (NTG). Shunt-treated normal pressure hydrocephalus (NPH) is a model for testing whether the increase (time from disease onset to CSF shunt placement, i.e., “protection period”) and decrease (time from shunt placement to observation, i.e., “exposure period”) in intracranial pressure (ICP) are glaucoma protective or risk factors, respectively. The authors estimated the prevalence of NTG in patients with shunt-treated NPH and calculated the extent of optic nerve exposure to changes in the trans–lamina cribosa gradient.

METHODS Data obtained in patients with NPH who had undergone ventriculoperitoneal (VP) shunt placement were analyzed. Patients with more than 6 months’ follow-up, no pathologies associated with ICP changes or CSF dynamics disturbances, and no surgical or valve-related complications were scheduled for ophthalmic evaluation.

RESULTS Nine of 22 patients had NTG, which is about a 40-fold increase in rate compared with the rate in the general elderly population without hydrocephalus (p < 0.001). The median protection period was 12.0 months in patients with NTG and 18.0 months in those without NTG (p = 0.033). The median ICP decrease multiplied by duration of exposure in months was 76.0 mm Hg × months in the NTG group and 24.1 mm Hg × months in the no-NTG group (p = 0.048). The patients’ median adjusted age (adjusted for “protection” and “exposure” times) was 85.1 years in the NTG group and 78.8 years in the no-NTG group (p = 0.001).

CONCLUSIONS A crucial risk factor for development of NTG in patients with shunt-treated NPH is the duration of optic nerve exposure to the lowering of ICP. Patients with NPH who are candidates for CSF shunting should be informed of the risk of incurring glaucoma. Longitudinal studies could provide estimates of tolerated times for a given ICP decrease.

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