gms | German Medical Science

Objective: Free hand placement of ventricular catheters (VC) is reported to be inaccurate in up to 40% of cases. Easy applicable techniques are necessary to warrant safety in an apparently simple procedure. We developed an easy to use guide for ventricular catheter placement.

Methods: Volume MR data sets of twenty one patients (2–18 years) were analysed to define the relevant parameter for individual frontal VC placement. In this context a newly designed guide was developed to apply the accurate placement of the VC. The guide was tested in a model to quantify placement precision following computer tomographic imaging. In addition the guide was applied in sixteen patients (12.5±8 yrs) in whom ventricular catheter placement was indicated.

Results: While using a rectangular approach in sagittal section, in 3D MRI measurements the angle to the tangent in the coronal section was defined as relevant parameter for correct VC placement. The optimal angle ranged between 91.96±2.75° to 99.56±4.14°, which appeared to be stable also in laterally shifted entry points. The guide was designed to apply this parameter and was tested in an agarose model and subsequent CT imaging resulting in mean angle deviation of 1.1 ±0.7° and 1.6 ±0.8 mm tip deviation at a length of 7 cm. Using the Guide in a selected patient cohort with narrow ventricles an immediate correct VC placement in patients was possible.

Conclusions: VC placement in narrow ventricles requires accurate placement of VC, with simple means in order to be applied as routine in all patients. The simple and feasible guide, we presented, is capable to fulfil this goal.