gms | German Medical Science

Objective: The etiology of hydrocephalus is heterogeneous, whereas the idiopathic normal pressure hydrocephalus (50%), posthemorrhagic (23%) and posttraumatic hydrocephalus (12.5%) are most common. The treatment of choice is the implantation of a ventriculoperitoneal shunt system. Shunt infections are the second most common complications after mechanical dysfunctions and are described in between 2 to 41%. The morbidity in affected patients is highly increased because of the primary infection and the associated surgical revisions. Some risk factors were described for pediatric patients, as previous CSF infections or a younger age, whereas the knowledge of those risk factors in adult hydrocephalus patients is rare. The study aimed to evaluate adult patients with implanted shunt systems concerning the incidence of shunt infections compared to the current literature and to analyze associated risk factors, especially the impact of the underlying hydrocephalus entity.

Methods: We retrospectively analyzed all adult patients who underwent implantation of continuous CSF drainage in our department between March 2010 and May 2014 concerning shunt infections. We calculated the risk of developing an infection in a regression analysis for the different hydrocephalus etiologies. The relative risk of shunt infection was analyzed by an univariate and multivariate regression model. Subgroups were characterized by different hydrocephalus entities based on their origin diagnosis. The alpha-level was determined on 5% to achieve statistical significance with a power of 0.9.

Results: Overall 510 adult patients underwent shunt implantation within the mentioned time period with a median age of 69 years and a range from 18 to 92 years. Therefore 273 patients were male. The idiopathic normal pressure hydrocephalus (n=137) and patients after intracranial tumor surgery (n=113) built the largest populations followed by patients suffered from traumatic brain injury (n=58), intracerebral hematoma (n=80), subarachnoid bleeding (n=81) and other entities (n=41) like aqueduct stenosis or meningitis. Shunt infections with required surgical revisions occurred in 45 (8.8%) of all patients. Concerning the different hydrocephalus entities, patients who underwent shunt implantation after tumor resection showed a significant lower risk for shunt infections (OR 0.3; CI 0.1-0.7; p<0.05), whereas patients suffered from a subarachnoid hemorrhage showed a significant higher risk (2.5; CI 1.3-4.9; p<0.05).

Conclusion: The risk of symptomatic shunt infections seems to be in relation to the underlying hydrocephalus entity, whereas patients after intracranial tumor resection show a reduced number of infections and patients suffered from a subarachnoid hemorrhage have a significantly higher risk.