More About Shunts – Adjustments & Revisions

I wish I could say that once a shunt is in, life becomes normal again and all symptoms become a distant memory. While that can be true, and while I do try my best to provide hope for others going through health struggles, I also feel it is important to be informed in our medical decisions.

So here, we will discuss the possible post-shunt experiences, problems, and resolutions in regards to shunt revisions and shunt adjustments.

This post is specifically written with Intracranial Hypertension in mind, though there could be some similarities with Hydrocephalus. In the same way, most of the information is based off of my experience with the VP Shunt but may still pertain to other types of shunts.

Now, on to the post:

What is the Difference Between a Revision & an Adjustment?

Adjustment – A shunt adjustment is a relatively simple, non-invasive, in-office procedure. A magnetic programmer is placed near the shunt valve where it can adjust the setting on the shunt to either allow more or less CSF out. Not all shunts are programmable.

Revision – A shunt revision is a more invasive procedure where a neurosurgeon will go in to repair any malfunctions within the shunt. This could be as simple as clearing a blockage in the catheter, or it could mean replacing/repairing some or all parts of the shunt.

Why an Adjustment?

Sometimes, shunt surgery doesn’t appear to be entirely successful at first. You may unfortunately still experience symptoms as your body adjusts to the new device.

However, if symptoms continue to be bothersome or severe, it could be possible that the shunt might need an adjustment, if of course it is a programmable shunt.

Imagine a crowd of people rushing through a small door. Depending on how your CSF fluctuates, you may need an adjustment for that “door” to be opened wider. It may even take several adjustments before the proper setting is found.

You can picture the dial of a shunt as that of an old rotary phone. As an example, some brands may range from 200 to 30 in increments of 10. The lower the number, the more fluid that is let out.

If symptoms seem to be more along the lines of low pressure (Intracranial Hypotension), it could mean that the shunt is actually over-draining, which would warrant an adjustment in the opposite direction.

Being a shunt setting is adjusted using magnets, it is possible that exposure to magnets could change your shunt setting. While it likely takes something strong, such as an MRI, many patients have reported small magnetic objects affecting their setting. There is inconclusive evidence on the matter, but certain brands of shunts could be a factor in magnet sensitivity.

For me personally, I felt I was at the right setting when I began to experience both low and high pressure symptoms. While one would hope there would be no symptoms at all, that unfortunately isn’t always the case. My pressure can be pretty aggressive at times, which makes me thankful I have the shunt. But I know if I adjust to let any more fluid out, my low pressure symptoms would only become worse.

Why a Revision?

It can almost be expected to feel some occasional discomfort from a shunt. Our bodies don’t always appreciate the foreign matter we place inside of them. More often than not, this discomfort can go away in time.

However, if the pain becomes severe, debilitating, or concerning, it would be advised to reach out to your healthcare team in case a revision may be necessary.

There can be several reasons for the need for a revision. Here are some of the most common:

Infection – This type of malfunction most often occurs early on following shunt placement. Types of infections may vary, whether it be meningeal or start at the wound site. A spinal tap or shunt tap may be performed to collect and test CSF. Complete removal and replacement of the shunt may be necessary as well as antibiotics.

Uncomfortable Parts – Some shunt patients report pain or discomfort with the catheter that can be significant enough to require that the catheter be shortened. Others end up having the shunt removed altogether.

Issues with Parts – This could include disconnection of the catheter from the valve, damaged parts, or a kink in the catheter. Replacement, removal, or repair may be necessary.

Shunt Occlusion (blockage/clogging/obstruction) – Perhaps the most common of malfunctions, a shunt occlusion could happen at any time or even gradually over time with various matter within the body being the cause and with any part of the shunt being involved. Exploratory surgery could help detect and clear the blockage.

Please remember not to allow these possibilities to place fear in your mind. Rather, try and understand that many go years or even decades without ever having an issue with their shunt.

Signs of Shunt Malfunction

While your shunt may not be a complete cure, remember that it was still placed to help improve symptoms. Listen to your body for anything that does not feel right and never hesitate to reach out for help.

Here are what patients report leading up to a shunt malfunction:

• Symptoms return, usually with severity
• Nausea, vomiting
• Visual changes, such as papilledema 
• Extreme drowsiness
• Balance Issues, falling, dizziness, fainting or blacking out
• Fever, redness along catheter or around valve, swelling, high white blood cell count, pain/discharge at the incision site – all of which could indicate infection

What Tests Detect a Shunt Malfunction? 

The following tests may be performed to help detect if there is a shunt malfunction or to narrow down what exactly the malfunction is.

Imaging – X-rays (called “a shunt series”) might reveal issues like a breakage, disconnection from the valve, or a kink in the catheter. A CT or MRI (CINE MRI) might reveal a problem with the ventricles or the flow of the shunt. It is also possible for imaging to show no issues even if there is a malfunction.

Shunt Tap – This test is a bit more invasive, as it is somewhat similar to a spinal tap – but through your shunt valve. It can be an in-office procedure, though sterility is crucial, just as with a spinal tap. While it does not reveal opening pressure like a spinal tap does, it can determine if your shunt is actually pulling off fluid like it should. It can also be drained to relieve excess pressure, and the fluid pulled can be tested for any possible infection.

From my personal experience of having a shunt tap, the pain was minimal – just a slight prick of the needle, similar to bloodwork. A very small, un-noticeable portion of hair was also shaved at the insertion site.

Vision Test – While having a shunt may not completely remove all symptoms of IH, it isn’t exactly normal to have something like papilledema with a shunt, especially if you’re also taking medication. I’m not saying it doesn’t happen, but new or recurring visual issues usually point towards failure of treatment. In this case, your neurosurgeon may want to make sure your shunt is functioning properly in addition to reviewing other treatment options. For me, this was the first test to point towards a possible shunt malfunction.

Spinal Tap – A spinal tap may be performed to check for infection. It could also reveal increased ICP which is the opposite of what you would expect with a shunt.

Exploratory Surgery – This would be the most invasive test, as it would basically be brain surgery all over again to see exactly what or where the issue is. Unfortunately, the above mentioned tests don’t always show the issue, rendering this one a possibility. In my experience, this one was optional, and I was allowed to try other treatment methods first.

Conclusion 

Although shunts may come with their own list of problems as we have learned from this post, they can be life changing for many people. While the possibility of a malfunction might sound frightening or cause some hesitation in your choice to get a shunt, please know that some patients are able to go their entire lives without ever needing another surgery or repair. I know I have no regrets with getting my shunt, its adjustments, or my revision. My prayer is that you find success with your healthcare decision, no matter what your situation. As always, we are here with you and for you!

If you are preparing for a shunt revision or adjustment, I hope you have found this information helpful. If you have any questions, please do not hesitate to reach out. You can also read about my personal experience with both procedures here.

Many thanks to all who helped contribute their stories for the making of this post.