Systematic review and meta-analysis of external ventricular drain placement accuracy and narrative review of guidance devices.

BACKGROUND: Insertion of external ventricular drain (EVD) is one of the most common neurosurgical procedures performed worldwide. This is generally performed freehand, on the basis of anatomical landmarks. There is significant variability in the reported accuracy of freehand placement, lacking Level I evidence. We present the first meta-analysis of freehand EVD placement accuracy and technologies or techniques to enhance accuracy. METHODS: We report a systematic review of the Pubmed, Embase, and Cochrane Central databases according to MOOSE (Meta-analysis Of Observational Studies) guidelines. 37 studies were included for qualitative analysis and 19 studies (2983 cases) for quantitative analysis. RESULTS: There is substantial heterogeneity in the outcome measures used to report EVD placement accuracy. Of those nineteen studies reporting accuracy using the Kakarla grading system the mean rate of ideal ipsilateral frontal horn placement was 73% (standard deviation ±7%). The use of formal stereotaxic guidance is consistently reported to improve accuracy to >90%, although with variable outcome measures. However, the reported efficacy of other guidance devices or techniques is highly variable. The quality of studies directly comparing all existing non-stereotaxic devices with freehand EVD placement is poor and precludes any assertion of superiority to freehand insertion. CONCLUSIONS: We provide the first meta analysis of freehand placement accuracy. There is insufficient data to perform a meta-analysis of the relative efficacy of interventions to improve accuracy. Qualitative synthesis of reports of stereotaxic guidance is suggestive of higher accuracy than freehand placement.

Orthogonal external ventricular drain (EVD) trajectory from burr holes sited by junior neurosurgical staff is superior to freehand placement: An in-silico model.

External ventricular drain (EVD) or ventriculostomy placement is one of the most common neurosurgical procedures performed worldwide and is associated with complications including haemorrhage, malposition and infection. Several authors have attempted to define an ideal trajectory for placement, and scalp-mounted guidance devices have been devised to exploit the theoretical ideal orthogonal trajectory from the scalp to the lateral ventricles. However, uptake has been limited due to lack of demonstrated superiority to freehand placement. Previous modelling studies have failed to include a true-to-life sample of patients undergoing EVD insertion and excluded cases with midline shift or non-hydrocephalus indications. Further, none have attempted to model the orthogonal insertion of EVD via actual burr holes placed by junior neurosurgical staff. In our report of 58 cases of frontal EVD insertion in a low-volume Australian neurosurgical unit freehand EVD insertion resulted in acceptable placement in the ipsilateral frontal horn in 62% of cases, any ventricle in 22%, and in eloquent or non-eloquent brain in 16% of cases. The modelled orthogonal trajectory from the same burr holes, using post-procedural computed tomography scans and the S8 Stealth Station (Medtronic), resulted in superior placement; 80% in the ipsilateral frontal horn and 20% contralateral (p = 0.007). There were no significant malpositions associated with the modelled trajectories. In our series, 18% of freehand catheters required multiple placement attempts. In conclusion, our data suggests that an orthogonal trajectory may result in improved EVD positioning compared to freehand placement.

Ruptured "giant" supratentorial dermoid cyst.

Intracranial dermoid and epidermoid cysts are rare lesions formed from the inclusion of ectodermal elements during neural tube closure. Although not entirely consistent, imaging characteristics on CT and MRI can aid differentiation of dermoids and epidermoids, as can age at presentation, location and tendency to rupture. The distinction between dermoid and epidermoid lesions is important prognostically and may impact on surgical management as a subtotally resected dermoid is less likely to recur than its epidermoid counterpart. The distinction of large dermoid lesions as "giant" adds little to information regarding the natural history or prognosis of these lesions and should be abandoned.

Preliminary study of shunt related death in paediatric patients.

Hydrocephalus is a condition commonly encountered in paediatric and adult neurosurgery and cerebrospinal fluid (CSF) shunting remains the treatment of choice for many cases. Despite improvements in shunt technology and technique, morbidity and mortality remain. The incidence of early shunt obstruction is high with later failures seen less frequently. This review aims to examine mortality associated with mechanical failure of CSF shunts within Queensland. Neurosurgical and Intensive Care databases were reviewed for cases of mortality associated with shunt failure. Eight cases were identified between the years of 1992 and 2002 with the average age at death 7.7 years. Deaths occurred on average 2 years after last shunt revision. Seven of the eight patients lived outside the metropolitan area. Shunting remains an imperfect means of treating hydrocephalus. Mortality may be encountered at any time post surgery and delays to surgical intervention influence this. Alternative measures such as third ventriculostomy or the placement of a separate access device should be considered. In the event of emergency, a spinal needle could be used to access the ventricle along the course of the ventricular catheter.