Cerebrospinal fluid alterations following endoscopic third ventriculostomy with choroid plexus cauterization: a retrospective laboratory analysis of two tertiary care centers

Purpose This study sought to determine the previously undescribed cytologic and metabolic alterations that accompany endoscopic third ventriculostomy with choroid plexus cauterization (ETV/CPC). Methods Cerebrospinal fluid (CSF) samples were collected from infant patients with hydrocephalus at the time of index ETV/CPC and again at each reintervention for persistent hydrocephalus. Basic CSF parameters, including glucose, protein, and cell counts, were documented. A multivariable regression model, incorporating known predictors of ETV/CPC outcome, was constructed for each parameter to inform time-dependent normative values. Results A total of 187 infants were treated via ETV/CPC for hydrocephalus; initial laboratory values were available for 164 patients. Etiology of hydrocephalus included myelomeningocele (53, 32%), intraventricular hemorrhage of prematurity (43, 26%), aqueductal stenosis (24, 15%), and others (44, 27%). CSF parameters did not differ significantly with age or etiology. Glucose levels initially drop below population average (36 to 32 mg/dL) post-operatively before slowly rising to normal levels (42 mg/dL) by 3 months. Dramatically elevated protein levels post-ETV/CPC (baseline of 59 mg/dL up to roughly 200 mg/dL at 1 month) also normalized over 3 months. No significant changes were appreciated in WBC. RBC counts were very elevated following ETV/CPC and quickly declined over the subsequent month. Conclusion CSF glucose and protein deviate significantly from normal ranges following ETV/CPC before normalizing over 3 months. High RBC values immediately post-ETV/CPC decline rapidly. Age at time of procedure and etiology have little influence on common clinical CSF laboratory parameters. Of note, the retrospective study design necessitates ETV/CPC failure, which could introduce bias in the results.