Prior endoscopic third ventriculostomy does not increase ventriculoperitoneal shunt failure rate

PURPOSE

To determine whether prior endoscopic third ventriculostomy (ETV) influences the failure rate of subsequently placed ventriculoperitoneal (VP) shunts.

METHODS

Our institution's operative database and patient records were reviewed retrospectively to identify all paediatric patients who had undergone a first VP shunt or ETV at our institution between January 2012 and December 2015. Data was analysed using the Microsoft Excel, GraphPad Prism v7 and SPSS statistics. The literature on this topic to date was also reviewed.

RESULTS

Eighty-six children were included in the study: 61 patients had a primary VP shunt inserted during the study period and 25 had a VP shunt inserted following failed ETV. There was no significant difference in the underlying aetiology or age of the patients in each group. In the primary VP shunt group, 47.5% (29 patients) required shunt removal at an average of 274 days post-insertion (range 7 days to 3.4 years). The 1-year revision rate was 34.4%. In the shunt post-ETV group, 48% (12 patients) required shunt removal at an average of 207 days post-insertion (range 2 days to 2.7 years). The 1-year revision rate was 36%. The most common reason for revision in both groups was blockage.

CONCLUSIONS

We found no significant difference in failure rate or pattern between primarily inserted VP shunts and those inserted following an endoscopic third ventriculostomy. On the basis of this study and the small number of previously reported studies, we would advocate a trial of ETV where feasible to allow a chance at shunt independence.

Method for assessing the chronic toxicity of marine and estuarine sediment-associated contaminants using the amphipod Corophium volutator

Acute sediment toxicity tests do not test key life stage events such as moulting and reproduction and therefore do not reveal the longer-term effects of contaminant exposure. A laboratory method is described for determining the chronic toxicity of contaminants associated with whole sediments. The test is conducted using neonates of the estuarine amphipod Corophium volutator at 15 degrees C, salinity 25 psu and a 12 h light:12 h dark photoperiod. The endpoints are survival and growth after 28 days and survival, growth and reproduction of amphipods upon termination of test i.e. reproduction within all control vessels (ca 75 days). The sediment chronic toxicity test was used to investigate the effects of sediments spiked with environmentally relevant preparations of slightly weathered Alaskan North Slope crude oil, including a water-accommodated-fraction (WAF) and a chemically-dispersed (Corexit 9527) WAF. Sediment oil concentrations were quantified using ultra-violet fluorescence. The amphipods exposed to chemically dispersed oil had higher mortality and lower growth rates than control-, Corexit 9527- and WAF-exposed organisms, resulting in reduced reproduction. The described method supplements the standard acute sediment test and would be particularly useful when long-term ecological effects are suspected but acute tests reveal no significant mortality. The sediment chronic test reported herein has shown that sediment that was not evidently toxic during 10-day acute tests could have population-level effects on sediment-dwelling amphipods.