Shunt vs Duraplasty

Hi All! Just had an updated MRI and will be following up with neurosurgeon soon. Would like input to arm myself with knowledge and understanding.
I had bone only decompression w C1 laminectomy, worsening symptoms post op. Pre surgery, I had significant symptoms, 4.3mm herniation and restriction of csf flow. I also had enlarged ventricles on every MRI with the last showing abnormal elevated stroke volume and ventricles consistent with NPH. Post op my symptoms increased but my stroke volume went down slightly and remained at high normal. My neuroradiologist who just did my updated imaging no longer writes chiari malformation in my report. In fact, he specifically writes NO chiari malformation, however he notes tonsils still pegged, crowding of tonsils at foramen magnum, and little csf. Very confusing to me to see no chiari malformation when those are hallmarks of chiari. He also notes ventricles still enlarged with mild bowing of the septum. So…I wonder, if ventricles are enlarged and not draining and there’s restriction of flow around foramen magnum, would that be more of a shunt placement or duraplasty? Again, I will see my neurosurgeon. :slight_smile: But if any of you have input to help clear it up for me I’d appreciate the clarity. Is the crowding causing the back up of csf in ventricles, or is the csf production in ventricles just needing a shunt since theres is still a little csf flow at foramen magnum. I am thrown off by neuroradiologist saying no chiari when neurosurgeon is offering to do a duraplasty. Thanks.

Hey Missyjo,
Before I start I am not a dr and each case would need to be assessed by a neuro.
A shunt is used to divert the CSF around an issue, often from the ventricles to the peritoneal (VP) or the ventricles to the atrium of the heart (VA). The dura is a membrane which covers the entire brain and spinal cord. A duraplasty is like a patch for the dura. So in the region where the C1 laminectomy occurred they place the patch and this allows the CSF to flow via it’s natural route down through the spine.

I say ‘…each case would need to be assessed by a neuro.’ because for some a duraplasty, maintaining the existing CSF cistern mechanisms would be preferable, but for others a shunt maybe more applicable as the restrictions in the region could still be an issue post laminectomy. Sometimes an individuals posture and physiology can have an impact on which option maybe preferred.

Hope it helps
Merl from the Modsupport Team

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Good morning Merl, thanks for the response. So in your opinion, whether there’s chiari or not, if duraplasty is brought up again in an effort to relieve ventricles and increase flow around foramen magnum, even if chiari is taken off the table, duraplasty could still be an appropriate step?

In short, yes.
I doubt that duraplasty would be offered if it was not deemed as an appropriate option.
A shunt is a plastic tube, a foreign object in the body and over time they do deteriorate and have other issues ie blockages and breakages. I have required 7 surgeries related to the shunt (6 neurosurgical +1 abdominal). Shunts do fail. A duraplasty is a patch over a hole and maintains the body’s natural flow of CSF, where a shunt diverts the natural flow. Duraplasty is much less invasive than the insertion of a shunt.

Chiari may have been managed or ‘taken off the table’ but that does not mean that a patch won’t help to better manage CSF flow.

Merl from the Modsupport Team

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I second with what Merl said! Just because Chiari is taken off the table does not mean that you will not still have issues related to the surgery or from the old chiari malfunction. I think that your neurologist will recommend whatever they think is appropriate, so I would trust them, espeiccally because they treated the chiari.

I would also keep reaching out to the support network too! The other thing that you can do is get multiple opinions remotely. I am not sure what the costs associated to this. When I was young going through the hospital, my mother did this a lot. She gathered other doctor opinions over email and fax, this helped a lot with just reducing anxiety. We all know that getting treated (even by a trusted doctor) is stressful!

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In terms of the “Chiari/no Chiari” issue, you may be getting stuck on a semantic issue.

Most radiologists will use the common definition of >5mm of cerebellar tonsillar ectopia to meet the diagnosis of Chiari I Malformation(which may be why the newer reading mentions cerebellar tonsillar ectopia but no Chiari).

You can have <5mm of cerebellar tonsillar ectopia and symptoms or >5mm of cerebellar tonsillar ectopia and no symptoms.

In terms of shunt or no shunt, it is an important discussion to have with your treating MD. Coming here to get more education is always helpful. As Merl mentioned, shunts are imperfect devices, with a national failure rate of close to 40%. Treatment for failure is another operation(to replace the part that failed).

It is often difficult to distinguish the exact cause of symptoms. Remember simple pressure dynamics. If you have true hydrocephalus that is not improved with duraplasty, you will be left with increased intracranial pressure and more space around the cerebellum. Therefore, the tendency of the brain is to be pushed out of the way by the increased pressure(in your case increasing the risk of further cerebellar tonsillar ectopia if you have untreated elevated intracranial pressure(as well as putting additional pressure on the stitches holding the duraplasty in place increasing the risk of a CSF leak)).

Hope these thoughts help!


Thank you for your response Jakob. I feel like I’m reaching for a life preserver as I’m drowning in symptoms that keep getting worse. I have a curious mind and I appreciate this site to help me tread through these muddy waters, I’m always looking for knowledge and understanding.

Dr Trumble thank you. I appreciate you taking the time from your busy schedule to help bring awareness, knowledge and understanding to those whole are struggling in this group. :heart: :pray: