The Latest Research on Shunt Occlusion

Shunts are crucial medical devices used to treat hydrocephalus by diverting excess cerebrospinal fluid (CSF) away from the brain. However, they are prone to complications and they often malfunction or fail. One of the primary reasons for these malfunctions is occlusion, or blockage, which can prevent the shunt from effectively draining CSF.

Why is this important? 

Understanding the cause of occluded catheters is key to improving shunt systems and brings hope that future designs will offer more reliable treatments, improving the quality of life for individuals with hydrocephalus and reducing the need for frequent surgeries.

Shunt Occlusion

Shunt occlusion occurs when there is a partial or complete blockage within the shunt system, disrupting the flow of CSF. Blockages can occur in various parts of a shunt, including the proximal ventricular catheter (which is inserted into the brain) and the distal catheter (which drains CSF to another part of the body, like the abdomen). 

Occlusions are typically caused by blood cells, tissue, debris, or even bacteria blocking the shunt. When this happens, CSF can accumulate in the brain, increasing pressure, and potentially triggering symptoms of untreated hydrocephalus, such as headaches, nausea, and cognitive difficulties.

New Research on Shunt Occlusion

A 2024 study by Dr. Maria Garcia-Bonilla and colleagues sheds new light into shunt occlusion, revealing how blockages can form from clumps of blood cells, proteins, or other debris. The research explores whether the type or cause of hydrocephalus (such as posthemorrhagic hydrocephalus, myelomeningocele, brain tumor, or others) increases the likelihood of shunt failure due to occlusion.

 The study revealed several key points:

• Proximal catheter occlusion, or blockage in the portion of the shunt located in the brain, accounted for 90.4% of shunt revisions in the study.
• Cell or tissue clumps were found in 76.8% of the cases where shunts were removed due to a blockage. These clumps can block the drainage holes in the catheter, preventing the proper flow of CSF.
•  Shunt failure and tissue clumps were not linked to the type or cause of hydrocephalus (etiology). This suggests that an individual’s risk of shunt failure is not influenced by their hydrocephalus diagnosis.

Occlusion can affect anyone, regardless of the underlying cause of their hydrocephalus, and most frequently occurs in the proximal catheter of the shunt.

Click the dropdown to view images of occluded shunts that have been removed from patients, courtesy of the Harris Lab. Please be advised that these images contain tissue and blood.