Transcalvarial brain herniation volume as a predictor of posttraumatic hydrocephalus after decompressive craniectomy

In patients undergoing decompressive craniectomy for traumatic brain injury(TBI) there has been reported an incidence of hydrocephalus between 0-45%. There are several radiological and clinical features described in association with development of hydrocephalus. For study the influence of these factors we conducted a retrospective observational single-center cohort study in a tertiary care center with special attention to the transcalvarial herniation(TCH) volume after decompressive craniectomy.

We selected 50 patients that underwent decompressive craniectomy after closed head injury between january 2014 and January 2015. Hydrocephalus was defined as a modified frontal horn index greater than 33%, presence of Gudeman CT scan criteria or insertion of ventriculoperitoneal Shunt. Variables analyzed were: age, post-resuscitation Glasgow coma scale (GCS) score, pupil reactivity, Zunkeller index, presence of hygroma, TCH volume, craniectomy diameter and distance of craniectomy from midline. Logistic regression was used with hydrocephalus as the primary outcome measure.

17 patients developed hydrocephalus (34%). TCH volume after decompression(p < 0.01), subdural hygroma (p < 0.01), lower admission Glasgow Coma Scale score (p = 0.015), unilateral pupil reactivity(p = 0.042) and higher Zumkeller index(p = 0.044) were significant risk factors for hydrocephalus. Logistic regression analysis showed that factors independently associated with the development of hydrocephalus was the TCH volume (odds ratio 11.08; 95%CI 2.10, 58.4; p = 0.0046), and presence of hygroma (odds ratio 49.59; 95%IC 4.1, 459; p = 0.002).

There was a clear association between severity of TBI, TCH volume and subdural hygroma with the development of hydrocephalus. Clinicians should follow closely patients with those findings in order to avoid late deterioration.