Background: Ventriculoperitoneal (VP) shunt malfunction is an emergency. Timely diagnosis can be challenging because shunt malfunction often presents with symptoms mimicking other common pediatric conditions.
Methods: We performed a systematic review and meta-analysis to determine which commonly used imaging modalities; Magnetic resonance imaging (MRI), Computed Tomography (CT), X-ray Shunt series or Optic Nerve Sheath Diameter (ONSD) ultrasound, are superior in evaluating shunt malfunction.
Inclusion criteria: patients less than 21 years old with symptoms of shunt malfunction. We calculated the pooled sensitivity, specificity, Likelihood Ratios (LR+, LR-) using a random-effects model.
Results: Eight studies were included encompassing 1906 patients with a prevalence of VP shunt malfunction of (29.3%). Shunt series: sensitivity (14%-53%), specificity (99%), LR+ (23.2), and LR- (0.47-0.87). CT scan: sensitivity (53%-100%), specificity (27%-98%), LR+ (1.34-22.87), LR- (0.37). MRI: sensitivity (57%), specificity (93%), LR+ (7.66), and LR- (0.49). ONSD: sensitivity (64%), specificity (22%-68%), LR+ (4.4-8.7), LR- (0.93). A positive shunt series, CT scan, MRI, or ONSD has a post-test probability of (23%-84%). A normal shunt series, CT scan, MRI, or ONSD results in a post-test probability of (7%-31%). A positive shunt series results in a post-test probability of 80%, which is equivalent to the post-test probability of CT scan (23-84%) and MRI (83%).
Conclusion: Despite the low sensitivity, a positive shunt series obviates the need for further imaging studies. Prompt referral for neurosurgical intervention is recommended. A negative shunt series or any result (positive or negative) from CT, MRI, or ONSD will still require an emergent neurosurgical referral.
Keywords: Computed tomography; Likelihood ratios; MRI; Sensitivity; Shunt series; Specificity; Ventriculoperitoneal shunt.
Published by Elsevier Inc.