Accurate placement of parieto-occipital shunt ventricular catheter: use of craniometrics and technical note

Ventriculoperitoneal shunt insertion is one of the most commonly performed procedures in neurosurgery but has a relatively high complication rate. One important source of complications is shunt malposition from erroneous placement of the parieto-occipital burr hole or poor shunt trajectory. There are significant variations in the freehand parieto-occipital approach amongst neurosurgeons that are derived from variations in technique or experience. The patient's skull shape or size is also often not taken into consideration if fixed measurements are used to define the burr hole entry point. The authors suggest a variation to the technique of ventricular catheter placement by relying on the patient's own craniometrics and skull landmarks.

The technique is illustrated and supported by analysis of a case series of 25 patients undergoing shunt placement.

By this method, all shunts were positioned in the lateral ventricle. Using a 3-point scale, the catheter position was evaluated: grade 1, free floating in cerebrospinal fluid; grade 2, touching the choroid plexus or ventricular wall; and grade 3, tip within the parenchyma. The catheter position was grade 1 in sixteen (64%) cases and grade 2 in nine (36%) cases; none was grade 3. Only one shunt malfunction occurred from proximal shunt obstruction in the series.

The use of this technique aims to reduce operator and patient variability as contributors to shunt malposition, to increase user reproducibility and decrease the learning curve for trainees. Further prospective study could be designed to validate the technique.