Real-time ultrasound guidance for ventricular catheter placement in pediatric cerebrospinal fluid shunts

Cerebrospinal fluid shunt failure is related to additional morbidity. Misplacement of ventricular catheters occurs in 40 % with freehand technique and is a risk factor for shunt failure. The goal of this study was to analyze the impact of intraoperative real-time ultrasound on catheter positioning and outcome in children.

We compared children receiving ultrasound-guided procedures to matched historical freehand controls. Burr hole and convex probes were used (ProSound Alpha 6, Hitachi Aloka Medical Ltd., Tokyo, Japan). Catheter position was graded as grade I (optimal), II (contralateral ventricle or contact with ventricular structures), or III (misplacement). Correlation analysis was performed to identify determinants of outcome.

The study group (n = 17) was balanced with the control group (n = 14) for variables such as mean age (4.7 vs 4.3 years) and preoperative frontal occipital horn ratio (FOHR; 0.45 vs 0.43). In the study group, grade I catheter position was achieved in 6 (35%) and grade II in 11 patients (65%), compared to 2 (18%) and 3 patients (27%) in the control group. While no grade III position occurred in the study group, it was found in nine control patients (43%) (P = 0.0029). Failure rate was highest in grade III (83%) compared to grade I catheters (50%).

This analysis demonstrated an improvement of catheter positioning with ultrasound guidance. In the absence of additional burden or risks, this method should be favored over freehand technique. It remains to be demonstrated in a randomized controlled fashion to what extent improved catheter position translates into improved outcome.