What is the frequency of Ventriculoperitoneal (VP) shunt occlusion?

From the Guidelines

Ventriculoperitoneal (VP) shunt occlusion is a common complication, occurring in approximately 5-30% of patients with shunts, with the highest rates within the first year after placement. The frequency of VP shunt occlusion varies depending on several factors, including patient age, underlying condition, and time since shunt placement 1. Children experience higher rates of occlusion than adults, with pediatric patients having approximately 30-40% chance of shunt failure within the first year 1. The proximal catheter (ventricular end) is most commonly occluded, often due to choroid plexus ingrowth, brain tissue, or blood clots. Distal catheter occlusions occur less frequently and may result from peritoneal adhesions, pseudocysts, or catheter migration. Patients with high protein or blood in their cerebrospinal fluid have increased risk of occlusion 1.

Some key points to consider in the management of VP shunt occlusion include:

• Regular clinical monitoring is essential for patients with VP shunts, with particular vigilance during the first year after placement when the risk of occlusion is highest 1
• Symptoms of shunt occlusion include headache, nausea, vomiting, altered mental status, and in infants, increased head circumference or bulging fontanelles
• Shunt malfunction or superinfection should be managed with a single- or double-staged surgical revision, depending on the presence of infection 1
• Maintenance steroid therapy may decrease the frequency of shunt blockages, and shunting combined with antiparasitic drugs may reduce the incidence of shunt failure 1

Overall, VP shunt occlusion is a significant complication that requires prompt recognition and management to prevent morbidity and mortality. The most recent and highest quality study recommends a single-procedure revision for shunt malfunction, and a two-stage procedure for infected shunts 1.

From the Research

Frequency of Ventriculoperitoneal (VP) Shunt Occlusion

• The frequency of VP shunt occlusion is a common complication, with studies indicating that mechanical obstruction of VP shunt during the first year after shunt implantation is widely described in the literature 2.
• According to a study published in 2022, shuntography revealed mechanical complications of the VP shunt in 37% of patients as a cause of clinical deterioration and following revision operation 2.
• Another study published in 2023 reported that VP shunt malfunction rates are as high as 40% in the first year, with posthemorrhagic hydrocephalus (PHH) patients having the highest proximal occlusion risk 3.
• A retrospective cohort study published in 2017 found that at least 1 VP shunt complication occurred in 23.8% of patients, with the cumulative rate of VP shunt revision being 22.0% 4.
• The frequency of VP shunt occlusion can be as high as 11-25% within the first year of initial implantation, according to a review article published in 2021 5.

Types of VP Shunt Occlusion

• Mechanical obstruction was discovered in 78% of patients, with disconnection of shunt components in 22% 2.
• In the obstruction group, the closure was detected in the ventricular catheter in 50%, in the distal catheter of the VP shunt in 29%, and in both sides of the VP shunt in 21% 2.
• Proximal catheter occlusion is a common complication, often leading to emergency surgery, morbidity, or even death 3.

Prevention and Treatment of VP Shunt Occlusion

• The use of a prophylactic retrograde-flushing device and routine prophylactic flushing protocol may reduce proximal obstruction and need for revision surgery 3.
• Shuntography can produce valuable clinical information uncovering mechanic complications after implantation VP shunt in patients with idiopathic normal-pressure hydrocephalus 2.
• Prompt and accurate on-ward revision could save the implant in most patients without CSF infections 6.