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December 3, 2012

A Tale of the Unexpected
By Carolyn Gutierrez
For The Record
Vol. 24 No. 22 P. 22

Following a family tragedy, acclaimed author Roald Dahl put down his pen to spearhead the invention of a better device to combat hydrocephalus.

In “Marvelous Medicine: the Untold Story of the Wade-Dahl-Till Valve,” published in the May issue of the Journal of Neurosurgery: Pediatrics, lead author Adam L. Sandler, MD, chronicles Roald Dahl’s extraordinary and largely unknown contribution to the treatment of hydrocephalus. In the early 1960s, prompted by his infant son’s struggle with the condition following a traffic accident, Dahl joined forces with a British toymaker and neurosurgeons from both sides of the Atlantic to develop an innovative valve and shunt system that would be used to treat more than 3,000 children and ignite a sea change in the field of valve technology.

Sandler, a resident in the department of neurological surgery at New York’s Albert Einstein College of Medicine/Montefiore Medical Center, was gathering information on hydrocephalus valves when he came across a mention of the Wade-Dahl-Till (WDT) valve. With his background as an undergraduate history major and affection for the prolific author, Sandler was intrigued by Dahl’s unexpected connection to the world of neurosurgery. He wanted to learn more, but online searches yielded only vague accounts of the WDT valve.

In a stroke of serendipity, Sandler came across a New York Times article about an upcoming book called Storyteller: The Authorized Biography of Roald Dahl by longtime Dahl scholar Donald Sturrock. (The biography has since been published.) Sparked by this discovery, a determined Sandler tracked down the author through his agent.

“I said, ‘Listen, I know it might sound crazy, but I’m a neurosurgical resident and there’s this valve—the story has never been told, and I think that Dahl deserves credit for this,’” Sandler recalls. Sturrock informed Sandler that there was a file in the archives at the Roald Dahl Museum and Story Centre in Buckinghamshire, England, devoted to the details of the WDT valve’s development.

After gaining permission from Dahl’s widow, Sandler received a large package filled with Dahl’s writings, photos, diagrams, and transatlantic correspondences. Working with Sturrock and a neurology team from Albert Einstein, Sandler pieced together the history of the WDT valve, demonstrating that fiction writers and neurosurgeons can make strange but brilliant bedfellows.

Theo’s Accident
A family tragedy set in motion Dahl’s association with the treatment of hydrocephalus. In December 1960 in New York City, the family nanny was walking with 3-year-old Tessa Dahl and 4-month-old Theo Dahl when a taxi plowed into the baby carriage, throwing it 40 feet into the air until it crashed into the side of a parked bus. Miraculously, Theo survived, but his skull was shattered.

In the emergency department at Lenox Hill Hospital—where at the time there was no pediatric neurosurgeon on duty—the outlook was grim. According to Sandler’s article, “From Dahl’s diary, it emerges that the author was highly critical of the care that Theo received at Lenox Hill, yet that critique is no doubt colored by the emotions of a distraught father in the throes of a desperate situation.” According to Dahl’s notes, a pediatrician and an adult neurosurgeon locked horns over what steps to take in treating Theo. Radiographs showed that the baby had no injuries other than multiple skull fractures.

Dahl and his then wife, actress Patricia Neal, weary of the chaos at Lenox Hill, transported their son to the neurology department at Columbia Presbyterian Hospital, where the boy was tended to by Milton Singer, MD, the family’s pediatrician, and neurosurgeon Joseph Ransohoff, MD. Theo was diagnosed with traumatic hydrocephalus, commonly known as “water on the brain.”

Causes of Hydrocephalus
Located deep in the middle of the brain are fluid-filled cavities called ventricles. Cerebral spinal fluid (CSF) originating from these ventricles circulates through the central nervous system, bathing and protecting the brain and the spinal cord.

“There are many benefits of the fluid,” Sandler says. “Our brain moves around a little bit in our skull, and the fluid acts as a shock absorber. It also helps our brain transport waste. When we are thinking, when we’re interacting with people, our brains are metabolizing glucose—they are working just like our muscles are working—and they make waste products. The fluid helps bathe away the waste products.”

After circulating through the central nervous system, CSF is absorbed back into the brain. Hydrocephalus occurs when the normal flow of CSF is blocked, not absorbed properly, or overproduced. When the CSF does not circulate properly, intracranial pressure builds, leading to an array of symptoms (depending on the patient’s age), ranging from headaches, vomiting, and seizures to blindness, an inability to look up, and brain function impairments. Irritability, poor coordination and gait, and loss of bladder control are other possible symptoms.

Hydrocephalus can be brought on by a brain tumor, an infection such as meningitis or, as in the case of Theo Dahl, by trauma to the head resulting in severe bleeding. Although it can be found in adults, it is more frequently seen in children and can be a congenital disease that oftentimes is detected during a prenatal ultrasound. Hydrocephalus is often found in children born with spina bifida.

In aqueductal stenosis, a common form of hydrocephalus, the aqueducts that act as channels to circulate CSF are blocked or too narrow, causing an imbalance in the amount of circulating fluid. Some families are genetically predisposed to narrow or closed-off aqueducts; babies who have extremely large heads are often manifesting the first signs of hydrocephalus.

In people of all ages, hydrocephalus caused by severe infection in the CSF or a brain hemorrhage results in weblike scarring throughout the brain, blocking the proper flow of CSF. In traumatic cases such as Theo’s, the blood hampers the brain’s ability to absorb the fluid, according to Sandler.

Relentless Blockages
After two weeks in an oxygen tent and several surgeries to drain the excess fluid from his brain, Theo was discharged. However, shortly thereafter he began to show signs that he wasn’t quite himself. Silent and unsmiling, he seemed to experience delayed reactions. A psychiatrist friend of the Dahls suspected that Theo was blind.

Theo returned to the hospital and after an emergency ventricular drainage procedure, Ransohoff implanted a shunt and valve system to relieve pressure on the brain. In the process, Theo’s sight returned. But not long after coming home, his vision deteriorated—the shunt had experienced a blockage.

The shunt was replaced, but the blockage problem persisted. During a span of nine months, Theo returned to the hospital six more times.

Shunt Technology
“Until about the 1950s, hydrocephalus was essentially a death sentence because there was no surgical answer for curing it,” Sandler explains. “In the 1950s, [neurosurgeons] developed a shunt. They decided they were going to try to shunt the fluid. In other words, divert the fluid from the brain to elsewhere, the idea being that if you could create a passageway from those cavities to other parts of the body maybe those other organs in the body … could just absorb the fluid.”

A ventriculoperitoneal shunt, a catheter made from thin silicone tubing, originated in one of the ventricles of the brain and was threaded underneath the child’s skin, around the ear, down the neck, and into the abdomen where the fluid would be drained. Ventriculoatrial shunts were generally inserted into the jugular vein and guided down to the veins connected to a heart atrium, where excess CSF would be drained and absorbed by the blood. Alternative shunting systems included ventriculopleural shunts, which diverted the CSF to the chest cavity, and ventriculosinus shunts that were inserted into the venous sinuses within the brain.

Shunts were an imperfect solution for treating hydrocephalus. Along with concerns about infection and obstruction, it could be challenging to control the flow of the fluid passing through the shunt. Midcentury neurosurgeons also were concerned that the shunt could possibly drain too much CSF, further disturbing the delicate balance of fluid needed to maintain a healthy central nervous system.

Valves were designed to regulate the drainage of the shunt between the ventricles and the organs absorbing the excess CSF and to restore normal intracranial pressure.

The valve used on Theo’s shunt had been produced in 1955, and although revolutionary for its time, its design made it vulnerable to blockage and overdrainage. “Dahl saw what was going on, how his son had so many problems with the valve and the shunt early on, and realized that this technology was very primitive—he could do something better,” Sandler says.

A Collaboration Among Visionaries
According to “Marvelous Medicine,” Dahl, disenchanted by the limited scope of valve and shunt technology available to treat his son, “learned everything he could about the pathophysiology of hydrocephalus and became convinced that he could improve upon the existing models.”

When Theo was well enough to travel, the family moved back to England, where Dahl recruited help from “England’s first pediatric neurosurgeon, Mr. Kenneth Till,” according to the article.

A gifted, driven man much like Dahl himself, Till not only founded the pediatric neurosurgical department at the Hospital for Sick Children, Great Ormond Street in London (and later established the International Society for Pediatric Neurosurgeons), he respected and welcomed Dahl’s proposal to update the current valve technology and even encouraged Dahl to attend and observe his many shunt operations. Through Dahl, Till began a correspondence with Ransohoff in New York. An international exchange of ideas on advancing valve technology ensued, bringing about the preliminary specifications for an improved device.

To bring the new valve to life, Dahl reached out to toymaker Stanley Wade, an old friend and retired engineer who specialized in creating exquisitely minute hydraulic pumps. According to Sandler’s article, “[Wade] used those skills to build model planes and trains for children. What was most remarkable about those models, however, is that they were fueled by miniature engines utilizing tiny hydraulic pumps. Those pumps never became obstructed.”

In 1962, Wade created a prototype of the as-yet-unnamed WDT valve. Ransohoff (then affiliated with New York University) and attending surgeon Kenneth Shulman, MD, conducted animal studies with the new valve and reported positive results to their colleagues across the pond. Buoyed by the valve’s apparent success, Till began using the device on his own hydrocephalus patients in London. Dahl arranged a travel grant that allowed Till to finally meet with Ransohoff in New York to compare notes on the invention, which lead to further refinements.
Unlike other models that were made of plastic, the finished WDT valve was fashioned from stainless steel and was easy to sterilize. The device also was relatively inexpensive to produce. While the valve had been primarily designed for ventriculosinus shunts, the device proved to be amenable for use with ventriculoatrial shunts and a host of other shunting systems to treat hydrocephalus.

According to Sandler’s article, “Dahl, Wade and Till agreed to make no profit on the enterprise. Instead, they established a non-profit organization, ‘The Children’s Research Fund,’ at Great Ormond Street Hospital, which would possess the rights of manufacture.” It was extremely important to the inventors that the valve be readily available to patients in developing countries at a very low cost.

New Technologies
Since the 1960s, significant breakthroughs in imaging technology have enabled neurosurgeons to provide better treatment for hydrocephalus by simply getting a closer look at it. Nevertheless, treatment continues to be a work in progress. For example, many patients continue to require a series of procedures to periodically replace or adjust their shunts.

According to Leslie Sutton, MD, chief of neurosurgery at Children’s Hospital of Philadelphia, some children with hydrocephalus actually may be able to avoid using a shunt altogether if they are candidates for a procedure known as endoscopic third ventriculostomy. The procedure involves using a small surgical telescope to make an opening at the base of the brain to provide an escape route for the spinal fluid, he explains. However, “Not all cases of hydrocephalus respond to this, and the failure rate is similar to that for shunts,” he notes.

While infection remains a concern, some neurosurgery centers are placing shunts that are saturated with antibiotics in the hopes they may provide a measure of protection. However, the long-term benefit of such a tactic has not been definitively proven.

Although shunt placement in the abdomen remains the gold standard for CSF drainage, with the heart, chest cavity, and venous sinuses of the brain commonly used as alternative sites, neurosurgeons continue to seek other sites. For some extremely small premature infants with hydrocephalus, a subgaleal shunt may prove to be a safer choice. In this procedure, “A pocket is made in the scalp, and the fluid is diverted there,” Sutton notes.

New valve and shunt technology is being created that would cut down on the number of surgeries and adjustments. Valves currently in development use microchips with sensor devices to accurately regulate the flow of fluid. Although the long-term benefits have not been proven, handheld devices that can noninvasively control drainage pressure have been used in some patients.

Marvelous Medicine
Although successful for its time, the WDT valve eventually experienced its share of mechanical failures because it was prone to occasional overdrainage. Modern shunt valves gradually replaced the WDT device, but during the 1960s, Dahl’s perseverance and commitment to creating a new valve brought about a renewed sense of urgency in addressing hydrocephalus in the neurosurgical community.

“Dahl was someone who realized that the status quo was inadequate and that he could do better,” Sandler says. “I think that is such a great lesson for humanity in general—just the idea that we can always do better.”

In 2011, Sandler gave a presentation about Dahl and the WDT valve at the American Association of Neurological Surgeons’ Annual Scientific Meeting to much fanfare. Since then, neurosurgeons have told him how they use the article to inspire the parents of newly diagnosed babies or children with hydrocephalus.

By the mid-1960s, when the WDT valve was at last available for use in the operating room, Theo Dahl’s hydrocephalus had resolved on its own. Nevertheless, according to Sandler’s paper, Roald Dahl remained a spokesman for the disease and an active member in the National Association for Spina Bifida and Hydrocephalus. Dahl answered letters from distressed parents around the globe whose lives had been touched by hydrocephalus, sharing with them the saga of his own son’s illness, a tale that in some respects was not unlike many of his acclaimed children’s stories in which ingenuity and imagination save the day.

— Carolyn Gutierrez is a freelance writer in New York City.