Hydrocephalus Treatment Advances: time to shunt the outdated shunts

Imagine being in so much pain it is impossible for your brain to shut down and fall asleep. Worse yet, you cannot sit up, stand up, or walk around because the act of lifting your head makes the pain even more unbearable.

This is what it’s like to experience an overdrainage headache, one of the four most common reasons why hydrocephalus patients with a ventriculoperitoneal (VP) shunt need shunt revision surgery (FDA 2021). Over half of hydrocephalus patients experience one or more of these complications by the time they are four or five years old (Kestle et al., 2000; McGirt et al., 2002). Eighty-one percent of hydrocephalus patients undergo at least one shunt malfunction by the age of twelve (Saint-Rose et al., 1991) and some patients have more than two dozen shunt revisions over a lifetime (Mitchell et al., 2021). The high failure rate of both programmable and fixed-pressure shunts means hydrocephalus patients experience a lot of pain, surgery, and infection. Further research on alternate treatments for hydrocephalus is therefore crucial.

What is hydrocephalus?

Typically, cerebrospinal fluid (CSF) flows in and around the four ventricles or cavities in the brain, providing nutrients and protection from injury. There are two main forms of hydrocephalus: obstructive hydrocephalus, in which the CSF is blocked, and communicating hydrocephalus, in which the CSF cannot be reabsorbed (Hydrocephalus, 2017). In both cases, CSF accumulates in the brain, causing swelling in children with skull bones that have not fused together and headaches, developmental delay, lower school performance, lethargy, gait disturbances, nausea, fainting, irritability, restlessness, vertigo, and vomiting in older patients (FDA, 2021; Hydrocephalus Association, 2021; Fallon, 2020). These symptoms can be attributed to the disruption in blood flow to the brain caused by CSF accumulation, which damages nerve cells and surrounding blood vessels, resulting in cognitive and motor skill deficits.

Pediatric hydrocephalus, the most common reason for child brain surgery, occurs in 1 in 770 newborns, according to the Hydrocephalus Association (2021). The more revisions patients undergo, the more their perception of their health and their quality of life decreases.

My experience with hydrocephalus

I was one of those 1 in 770 babies. In elementary school, combing my hair caused so much pain and upset that my mother and I fought over how short my hair should be until I got the hair cut I have now through brain surgery. I couldn’t participate in gym class in high school because I got hit in the head three times, so it was decided I could no longer be in the room with a ball that might injure my head. I’m not the only one; for some patients, it’s much worse. They must alter their behavior regarding hair styles, sleeping positions, and activities (Mitchell et al., 2021).

I feel lucky that I was not part of the 81% of children who experience one or more shunt malfunctions by the age of twelve, but I am frustrated that I received the same treatment as a baby with hydrocephalus received in the 1950s (Aschoff et al, 1999). The primary advancement in the treatment of hydrocephalus is the programmable shunt, a new type of shunt that doctors can non-invasively adjust to accommodate more or less fluid (Mitchell et al., 2021).

However, programmable shunts don’t feel like much of an upgrade. According to the FDA, magnets in Magnetic Resonance Imaging (MRI) can disrupt a patient’s programmable shunt setting. For hydrocephalus patients, that means that getting an MRI to examine their shunt and ventricle function may lead to risk of a shunt malfunction headache. Therefore, although programmable shunts make it easier to reprogram the shunt without surgery, there is an increased risk of pain due to treatment monitoring. Fixed-pressure shunts may require surgery to reprogram, but they cannot unintentionally be reprogramed by MRI’s and cause a shunt-malfunction headache.

A shunt malfunction is unlike any other pain I have ever felt. Not only are Tylenol and hydration ineffective for pain relief, but even oxycodone dispensed in the hospital doesn’t help. It should not be acceptable to let hydrocephalus patients go through that kind of pain for any amount of time when the comparable alternative, fixed-pressure shunts, do not cause that issue.

In my case, my brain had already found an alternative method of draining its CSF fluid after my original shunt malfunctioned, so I did not need the programmable shunt. Instead, the doctors were going to perform an endoscopic third ventriculostomies (ETV), a procedure which connects the third ventricle to the basal cisterns and creates an alternate pathway to drain CSF fluid (Torres-Corzo et al, 2016), but scar tissue blocked the surgery site. They instead performed anaqueductal plasty, an endoscopic procedure that reopens communication between the third and fourth ventricle using a balloon catheter and has a 50% rate of re-occlusion (Torres-Corzo et al, 2016).

ETVs are a new treatment option

It has only been in more recent years that hydrocephalus does not automatically mean shunt dependence. ETVs are becoming the preferred treatment option for hydrocephalus because the risk of infection associated with ETVs is less than one percent and other complications are also rare (Teo et al., 201; Hydrocephalus Association, 2021). They also have a high success rate – between 68% and 90% (Choudhary et al., 2020; Teo et al., 2013; Rahman et al., 2021), meaning that most patients with hydrocephalus are reduced to one shunt, and some even gain shunt independence.

With the growing body of research on ETVs, shunt malfunction headaches might someday be a thing of the past, and future hydrocephalus patients will not need to rely on a foreign device to regulate their CSF fluid. However, more research needs to be done on the long-term care of individuals who undergo an ETV and their quality of life.

Most studies focus on brain function, infection, and obstruction to determine success or failure rate, but more studies need to be done on what patients really care about: quality of life outcomes (Mitchel et al., 2021). When I was diagnosed with hydrocephalus, my mother wanted to know what the diagnosis would mean for me. Two decades later, that is still the big question in the minds of patients and caregivers. Researchers and surgeons care about the quantitative data that tells them how effective or risky ETVs will be. But to a patient or caregiver, that means nothing without the qualitative data telling them what effects it will have on their work performance, school performance, sleep schedule, and mood.

For decades, researchers have studied the effectiveness, side effects, and the quality of life outcomes of VP shunts for hydrocephalus. If ETVs are going to become the new gold standard, the same body of research that exists for VP shunts needs to be built for ETVs, but the potential for ETVs to improve quality of life for hydrocephalus patients is promising.

~~~

Written by Rebecca Munday

Edited by Sean Noah, Carolyn Amir and Caitlin Goodpaster

Illustrated by Himani Aurora

~~~

Become a Patron!

References
Aschoff, A., Kremer, P., Hashemi, B., & Kunze, S. (1999). The scientific history of hydrocephalus and its treatment. Neurosurgical review, 22(2-3), 67–95. https://doi.org/10.1007/s101430050035

Choudhary, A., Sobti, S., Zambre, S., & Bhaskar, S. (2020). Endoscopic Third Ventriculostomy in Failed Ventriculoperitoneal Shunt in Pediatric Population. Asian Journal of Neurosurgery, 15(4), 937–940

Cincinnati Children’s Hospital Medical Center.(2018). Endoscopic Third Ventriculostomy. Cincinnati Children’s Hospital Medical Center. https://www.cincinnatichildrens.org/health/e/endoscopic/.

Gale. Fallon, L. F. (2020). Hydrocephalus. In J. L. Longe (Ed.), Gale virtual reference library: The Gale encyclopedia of medicine (6th ed.). Credo Reference: https://go.openathens.net/redirector/georgiasouthern.edu?url=https%3A%2F%2Fsearch.c redoreference.com%2Fcontent%2Fentry%2Fgalegm%2Fhydrocephalus%2F0%3FinstitutionId%3D3816.

Food and Drug Administration. (2018, August 28). Risk of CSF Shunts. fda.gov https://www.fda.gov/medical-devices/cerebral-spinal-fluid-csf-shunt-systems/risks-csf- shunts.

Gale. Hydrocephalus. (2017). In Gale (Ed.), Human diseases and conditions (3rd ed.). Credo Reference: https://go.openathens.net/redirector/georgiasouthern.edu?url=https%3A%2F%2Fsearch.credoreference.com%2Fcontent%2Fentry%2Fgalehuman%2Fhydrocephalus%2F0%3Finst itutionId%3D3816.

Hydrocephalus Association. (2021).Complications of ETV. Hydrocephalus Association. https://www.hydroassoc.org/complications-of-etv/.

Hydrocephalus Association. (2021).Complications of Shunt Systems. Hydrocephalus Association. https://www.hydroassoc.org/complications-of-shunt-systems/.

Hydrocephalus Association. (2021). Shunt Systems. Hydrocephalus Association. https://www.hydroassoc.org/shunt-systems/.

Jaime Torres-Corzo, Leonardo Rangel-Castilla, & Peter Nakaji. (2016). Neuroendoscopic Surgery. Thieme.

Kestle, J., Drake, J., Milner, R., Sainte-Rose, C., Cinalli, G., Boop, F., Piatt, J., Haines, S., Schiff, S., Cochrane, D., Steinbok, P., & MacNeil, N. (2000). Long-term follow-up data from the Shunt Design Trial. Pediatric Neurosurgery, 33(5), 230–236. https://doi.org/10.1159/000055960.

Wiley. lateral ventricles. (2012). In F. J. Dye, Dictionary of developmental biology and embryology (2nd ed.) Credo Reference: https://go.openathens.net/redirector/georgiasouthern.edu?url=https%3A%2F%2Fsearch.credoreference.com%2Fcontent%2Fentry%2Fwileydevbio%2Flateral_ventricles%2F0%3FinstitutionId%3D3816

McGirt, M. J., Leveque, J.-C., Wellons, J. C., 3rd, Villavicencio, A. T.,Hopkins, J. S., Fuchs, H. E., & George, T. M. (2002). Cerebrospinal fluid shunt survival and etiology of failures: a seven-year institutional experience. Pediatric Neurosurgery, 36(5), 248–255. https://doi.org/10.1159/000058428.

Mitchell, Kerry-Ann S. MD, PhD; Zelko, Ian BS; Shay, Tamir MD; Horen, Sydney BA; Williams, Ally; Luciano, Mark MD, PhD; Huang, Judy MD; Brem, Henry MD; Gordon, Chad R. DO, FACS. (2021, July-August). The Impact of Hydrocephalus Shunt Devices on Quality of Life, Journal of Craniofacial Surgery: 32(5) 1746-1750 doi: 10.1097/SCS.0000000000007579.

Rahman, M. M., Khairun Nabi Khan, S. I. M., Robert, A. K., Islam, R., & Mainul, H. S. (2021). Endoscopic third ventriculostomy in children: Problems and surgical outcome: Analysis of 34 cases. Chinese Neurosurgical Journal, 7, 1-6. http://dx.doi.org/10.1186/s41016-020-00228-8.

Sainte-Rose C, Piatt J, H, Renier D, Pierre-Kahn A, Hirsch J, F, Hoffman H, J, Humphreys R, P, Hendrick E, B. (1991) Mechanical Complications in Shunts. Pediatric Neurosurgery 17:2-9. doi: 10.1159/000120557.

Teo, C., Kadrian, D., &Hayhurst, C. (2013).Endoscopic Management of Complex Hydrocephalus. World Neurosurgery, 79(2), S21. https://doi.org/10.1016/j.wneu.2012.02.015.