The 69-year-old man rose from his desk at the guard station in the front hall of the Veterans Administration Medical Center in Birmingham, Ala. He usually patrolled the entrance to the busy clinic once or twice an hour. This time, he didn’t take more than a dozen steps into the humid spring warmth before he felt the familiar symptoms he’d come to dread. His vision blurred. And he was lightheaded, but at the same time, he could sense his legs trembling as if he weighed much more than usual. He leaned against the cool brick wall but knew from experience he wouldn’t stay upright for long. He pulled out the radio at his belt and called for help.
Within moments he was in a wheelchair, heading for the emergency department. The man was embarrassed by his transient helplessness, even though it had happened many times before. He was supposed to be assisting those who came to the V.A. for their care. Instead, he was the one needing help.
In the E.D., the nurse confirmed what he already knew — he had what’s called orthostatic hypotension (O.H.). When his blood pressure was measured while lying flat, it was normal. But it plunged when he sat up. And when the nurse helped him to his feet, it dropped so low he almost fainted. This had been a problem for several years, off and on, but recently, it had become much worse. He ended up in the E.D. a half-dozen times these past few months. His doctors advised him to drink more water. He did. And he tried to wear the compression stockings he was prescribed. It was hard because they were hot, and when he wore shorts, he felt ridiculous. He tried to remember to get up slowly. That was the only thing that really helped.
Orthostatic hypotension occurs when inadequate blood gets to the brain because of a change in position. Normally, sitting or standing will signal the blood vessels in the legs and lower body to constrict, sending blood upward to the heart and ultimately to the brain. That change also tells the heart to beat more rapidly to help the blood get to the brain faster. Dehydration is a common cause of a positional drop in blood pressure. The blood vessels can’t constrict enough to send the blood to where it’s needed because there’s just not enough fluid in the circulation. Nerve problems can also cause O.H. It’s the nerves that tell the heart to beat faster and the vessels to squeeze a little tighter.
When this patient came to the E.D., he was often given intravenous fluids to try to fill up a suspected empty tank. It never seemed to help. That made his doctors think that in his case the cause was neurogenic — his nerves weren’t delivering their essential messages. And for this patient, that seemed a reasonable explanation, because it was clear that at least some of his nerves weren’t working well. He had a severe peripheral neuropathy that left his feet mostly numb, though occasionally they burned and tingled as if they were asleep.
Checking His Heart Rate
It was early morning when Dr. Matt Slief, a resident at the end of his first year of training, saw his newest patient. The cheerful silver-haired man described the strange spells he had when he stood up that more than once had landed him on the floor in a dead faint. “It doesn’t last long,” he told the young doctor, “but it sure is embarrassing.” Slief quickly examined the patient and promised to return later that morning with the rest of the team. After he finished seeing his patients, he hurried to the team room where he was to meet with Dr. Robert Centor, the attending physician. Centor was a couple of years older than the patient but still hard at work — though he described himself as semiretired.
After hearing about the patient with the positional changes in blood pressure, Centor asked the young doctor: “What was his heart rate?” Slief quickly checked. Every time the patient’s blood pressure went down, his heart rate went up, he reported. Centor nodded. “In that case, I doubt that his orthostatic blood pressure is caused by his nerves,” he said. If the nerves can’t tell the blood vessels to squeeze, they also won’t be able to tell the heart to beat faster — so in neurogenic O.H., the heart rate remains stable even when the blood pressure drops. And that’s not what happened with this patient.
Clearly his problem wasn’t in his nerves. And it didn’t seem to be a problem with blood volume, because giving him fluids never helped. There were other, less common causes to be considered. Centor challenged his team: What else could this be? By the time they next met, Slief had come up with an alternate possibility, but he worried it would sound far-fetched.
Years before, the patient had fallen in the bathtub, broken his ribs and punctured a lung. Blood filled his chest and collapsed the lung. He had to be rushed to the hospital. Patients who are stuck in bed while in the hospital are at risk of developing blood clots in the veins of their legs because they are immobilized. Clots form when blood isn’t moving. These patients are usually started on blood thinners to reduce that risk. Because this man had bled into his chest, blood thinners weren’t a good option for him. Clots that form because of immobility block veins and cause swelling and pain, but they can also be deadly if they travel through the body and end up in the lungs or brain. So his doctors had chosen to put a filter in the main vein that brought blood from his legs back to his heart — a vessel called the inferior vena cava — to catch any clots that formed and broke free.
These filters are supposed to be removed a few months later when the risk of clotting goes down, but many are not removed on schedule. This one had been left in place for more than 15 years. What if, Slief suggested after explaining this history, the filter had done its job and captured clots and they were now blocking the entire vessel? Could that cause his positional hypotension? Centor listened thoughtfully. He’d been a doctor for 45 years and had never seen this. And yet it was an interesting idea. Certainly worth considering.
One of the many advantages of the V.A. Hospital system is that it has computerized medical records going back decades. Slief did a deep dive into this man’s medical history and hit what looked like some promising results. Seven years earlier, the man had a CT scan that showed an almost total blockage of his vena cava. Was it possible that the extra blood that was supposed to go from the legs to the brain when the man stood up didn’t get there fast enough because of the narrowed vena cava?
The Daddy-Longlegs Device
There was really no way to test this hypothesis, but it made sense. They explained to the patient that the next step was to get the filter out. The patient was eager to try. The team reached out to Dr. Bill Parkhurst at the University of Alabama at Birmingham Hospital, who specialized in this kind of procedure.
The patient was sedated for the operation. Parkhurst put a tiny tube through an incision into the patient’s jugular vein in his neck and slowly advanced it down past the heart into the vena cava where the filter was located. These contraptions look like daddy longlegs with tiny hooks at each foot to hold them in place in the vein. Where the body of the insect would be located was a small hook. Parkhurst used a tiny gripping tool to grasp the hook and pull the filter up through the vena cava and out through the small incision in the patient’s neck. Next Parkhurst inserted tiny balloons that he inflated to reopen the threadlike stream through the narrowed vena cava. He then positioned a stent to hold the vessel open. He continued this process down the primary vein of each leg. The procedure took six hours and required nine stents, but finally there was good blood flow between the legs and the heart.
The first time the patient stood up after this procedure, he was amazed. The dizziness was gone. It has been four months and it hasn’t come back. No weak legs, no lightheadedness, no falls. His feet are still numb, but he can live with that so long as they remain on the ground and he remains upright.
Slief is modest about making this obscure diagnosis. There are only a handful of case reports in the medical literature. Still, Slief told me, it does make you wonder if maybe this is happening more often than reported. He’s certainly going to be looking for it.
Lisa Sanders, M.D., is a contributing writer for the magazine. Her latest book is “Diagnosis: Solving the Most Baffling Medical Mysteries.” If you have a solved case to share, write her at [email protected]