Ultrasound-guided versus stereotactically navigated ventriculoperitoneal shunt placement: a randomized clinical trial

Clinical Snapshot

Key Findings

• P Value: P = 0.002

• Effect Size: Mean difference −11.5 minutes in favour of US-G

• Primary Outcome: Surgical intervention time: US-G was significantly faster than ST-G

• Nnt Or Sensitivity: NNT not applicable for continuous primary outcome. Notable secondary finding: higher number of ventricular puncture attempts in the US-G group (exact figures not reported in abstract). Catheter accuracy and VPS dysfunction/complication rates were comparable between groups (effect sizes not reported in abstract).

• Confidence Interval: 95% CI −18.5 to −4.5 minutes

Clinical Application

Intraoperative ultrasound is widely available in most neurosurgical theatres and is less resource-intensive than stereotactic neuronavigation, which requires preoperative imaging registration and dedicated navigation hardware. US-G does not require preoperative MRI/CT co-registration, making it more accessible for urgent or semi-urgent cases. The learning curve for US-G VPS placement must be considered, and the higher puncture attempt rate in the US-G group suggests that technique standardisation and training are important prerequisites. In Australia, ventriculoperitoneal shunt surgery is performed across major public and private neurosurgical centres. Stereotactic neuronavigation systems (e.g., Brainlab, Stryker) are available at most tertiary centres but represent significant capital and per-case costs not universally reimbursed under Medicare. Intraoperative ultrasound is generally available and does not attract separate MBS item numbers beyond the operative procedure itself, potentially offering cost advantages. The TGA does not specifically regulate navigation modality choice for VPS, and RACS/ANZAN guidelines do not currently mandate a specific navigation technique. These findings may support a shift toward US-G in centres with appropriate expertise, with potential downstream benefits for theatre efficiency and healthcare costs under the Australian public hospital funding model. The higher puncture attempt rate warrants monitoring in the context of Australian neurosurgical credentialling and quality improvement frameworks. Adult patients with hydrocephalus or other indications requiring ventriculoperitoneal shunt insertion, particularly in centres with established intraoperative ultrasound capability and trained neurosurgeons

Abstract

BACKGROUND: Accurate catheter positioning is essential for optimal outcomes in ventriculoperitoneal shunt (VPS) surgery, while shorter operative times lower infection risk and costs. Navigated VPS placement, using either intraoperative ultrasound-guided (US-G) or stereotactically guided (ST-G) navigation, enhances catheter accuracy and reduces revision rates. However, high-quality studies comparing the two navigation methods are lacking. We aim to compare surgical intervention time, accuracy, and safety of US-G to ST-G VPS placement. METHODS: The Navigated VPS (NAVPS) trial was an investigator-initiated, randomized trial conducted from February 2020 to June 2024 in the Neurosurgical Department of the University Hospital of Basel. Consecutive adults undergoing VPS placement were included. Out of 153 screened participants, 134 participants were included. Participants were randomized 1:1 to receive either US-G or ST-G insertion of the ventricular catheter. The primary outcome was surgical intervention time. An intention to treat analysis was performed calculating surgical intervention time differences. Secondary outcomes were accuracy of catheter positioning, number of ventricular puncture attempts, and VPS dysfunction and complication rates. The study follow-up lasted 6 months. RESULTS: Of 134 participants, 66 were assigned to US-G and 68 to ST-G. The mean (SD) age was 73 (55.3 to 78) and 66 (54.5 to 73) years for the US-G and ST-G, respectively, and 58 participants (45.7%) were female. The US-G group had significantly shorter surgical intervention times compared to the ST-G group (-11.5 min; 95% CI -18.5 to -4.5; P = 0.002). The number of ventricular puncture attempts was significantly higher in the US-G group, while accuracy of catheter placement, and VPS dysfunction and complications rates were comparable in both groups. CONCLUSIONS: The NAVPS trial shows US-G VPS placement to be more time-efficient, while accuracy of catheter placement and complication rates seem to be comparable to ST-G placement. US-G can be efficiently and safely used in clinical practice. TRIAL REGISTRATION: clinicalTrials.gov Identifier: NCT04450797, date of registration: 22.06.2020.