You'd never know it from looking at her, but my sister Rachel has pressure settings.
The shunt drains excess cerebrospinal fluid that would otherwise over-accumulate inside her skull due to a congenital condition called hydrocephalus, or "water on the brain," that can damage brain tissue if left untreated. The apparatus directs the fluid from the magnetized pressure valve in her head down through a tube that leads to her abdomen, where it's re-absorbed by her body.
There was some good news, though. Rachel would be getting an upgrade to a Medtronic Strata valve, which can be adjusted non-surgically, unlike her old fixed-pressure shunt valve, which had to be calibrated before placement in her head and could only be adjusted later by way of a scalpel.
With her new type of valve, which was introduced in the U.S. in 2002, a doctor or technician simply places a strong magnet against the back side of her head and rotates a circular dial, like something you might see in the world of "Total Recall."
"It gives you a lot more flexibility," Michel Kliot, a professor of clinical neurosurgery at the University of California at San Francisco and my sister's surgeon, told me.
My sister says her new shunt doesn't feel any different than her previous systems, though she does periodically experience what she describes as a "spark sensation." More than thinking about the workings of the shunt itself lately, she finds herself pondering her complex relationship to technology.
"I am truly grateful and completely amazed by how technology has allowed me to live and thrive," she says, "but there is also the reality that technology can fail and cause great suffering, or, in the worst case, death. Devices have a certain shelf life, and that is just how it is."
Hydrocephalus can result from inherited genetic abnormalities or developmental disorders that block the flow of cerebrospinal fluid. Meningitis, tumors, or traumatic head injury can also cause the condition. Experts estimate that hydrocephalus affects approximately 1 in every 500 children. We suspect my sister was born with the condition, although it didn't officially manifest itself until age 12, when she suddenly began suffering from horrible headaches.
No matter the cause, surgical implantation of a shunt to redirect accumulated cerebrospinal fluid is the common solution, and one that normally needs to be in place for the patient's entire life. Shunts have been around for 50-60 years, Kliot says, though the early systems involved tubing alone. Valves came later, and the kind of programmable valve that now lives behind my sister's right ear represents the latest, most modern wave.
My sister's Medtronic Strata valve -- which measures 1.85 inches wide by 0.63 inches deep and 0.28 inches high -- carries a suggested retail price of between $3,000 and $4,000, depending on the configuration.
Such programmable valves signify an advance, to be sure, but Kliot admits that progress in shunt systems is lagging. They are still easily clogged with debris such as blood and protein particles, for one thing, and can't be cleared without surgery.
Fortunately, "people recognize it's a problem and they're trying to make better shunt systems," Kliot says.
Engineering a smarter shunt
One of those people is Samuel Browd, a pediatric neurosurgeon at Seattle Children's Hospital and the University of Washington's Harborview Medical Center.
First and foremost, the pair is focusing on producing a failure-resistant device that's less likely than current models to become clogged and break down, resulting in a life-threatening emergency. If the tubes on this newer shunt become blocked, they can recognize the obstruction and expand to let it pass through before assuming their previous shape.
"Our immediate goal is to reduce shunt malfunctions by 50 percent," Browd explains. "If we can meet that milestone, we'll have vastly improved the way hydrocephalus is treated."
Browd and Lutz are also building in an electronic data transmission feature that could record and offload data from onboard pressure sensors, letting doctors check the working status of a shunt remotely. This means that before long, clinicians could be relieving patients' shunt-related headaches by remotely dialing fluid flow up or down, in much the same way that those with pacemakers can now have their devices adjusted over the phone.
"You could envision it communicating with a smartphone app," Browd posits. "If you don't feel good, it could interrogate the valve, make sure the valve's functioning properly, check what the [intracranial pressure] is, and tell you that or relay that to your physician. That's I think where the future of this is going."
Time to schedule a tune-up
Electronics, of course, need power, and the valve on the next-gen device will have a battery life of eight years. That means families will be able to plan for battery-replacement procedures before the device fails unpredictably, as is so often the case currently. Getting a battery replaced would be a simple 30-minute maintenance procedure, Browd says. Think of it like scheduling a 70,000-mile tune-up.
Browd and Lutz have formed a company, Aqueduct Neurosciences, and hope to bring their shunt to market within five years with help from the UW's Center for Commercialization, which helps researchers take innovations beyond the lab. They are getting additional funding from the National Institutes of Health and Coulter Foundation, among others.
Though I fervently hope these advances never need to be applied to my sister, for my family, and others like us, they can only be reassuring.
"My last shunt lasted 19 years, so I am hopeful with the technological advancements that have taken place since then that I won't have any problems in the future," my sister says. "There are, of course, no guarantees. I've accepted this."
Fear, hope, and appreciation
Nonetheless, she has faced emotional challenges post-op -- dealing with the residual shock and fear of becoming ill so quickly and having to undergo major surgery; worrying about what the future holds for her health; and on a lesser scale, adjusting to her shaved head (early nicknames included "Sinead O'Katz," and her favorites, "Diva Monk" and "Monk Rocker").
Still, she's doing remarkably well. The excruciating headaches have dissipated and she's gone from needing daily medication for managing post-op pain to giving up pain pills almost entirely. In the weeks after the surgery, she'd push herself to walk just a few steps farther down the block each day. Now, she's back to her insanely intense workouts. She's returned to work as a counselor and hospice volunteer, and she even shares her soprano singing talents with patients at the hospital where she was so ill just a few months back.
All that she has endured, she says, while "at times, scary and overwhelming, has also provided me with the greater gifts of compassion, tenderness, vulnerability, appreciation, and acceptance. In an odd sort of way, technology has made me more human."