Years earlier, the patient had fallen into the bathtub, broken his ribs and punctured a lung. Blood filled his chest and collapsed the lung. He had to be rushed to hospital. Patients confined to bed in the hospital are at risk of developing blood clots in the veins of their legs because they are immobilized. Clots form when the blood is not moving. These patients are usually started on blood thinners to reduce that risk. Because this man had been bleeding into his chest, blood thinners were not a good option for him. Clots that form due to immobility block veins and cause swelling and pain, but they can also be fatal if they travel through the body and end up in the lungs or brain. So his doctors had opted to put a filter in the main vein that returned blood from his legs to his heart — a blood vessel called the inferior vena cava — to catch any clots that formed and dislodged.
These filters should be removed a few months later when the risk of clotting decreases, but many are not removed in time. This has been in place for over 15 years. What if, Slief argued after explaining this history, the filter had done its job and caught clots and was now blocking the entire blood vessel? Could that be causing his positional hypotension? Center listened intently. He had been a doctor for 45 years and had never experienced this. Still, it was an interesting idea. Definitely worth considering.
One of the many benefits of the VA Hospital system is that it has computerized medical records that go back decades. Slief dug deep into this man’s medical history and came up with promising results. Seven years earlier, the man had a CT scan that showed almost total blockage of his vena cava. Was it possible that the extra blood that had to go from the legs to the brain when the man stood up wasn’t getting 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 take out the filter. The patient was eager to try. The team contacted Dr. Bill Parkhurst of the University of Alabama at Birmingham Hospital, who specialized in this type of procedure.
The patient was anesthetized for the operation. Parkhurst inserted a small tube through an incision in the patient’s jugular vein in his neck and slowly pushed it past the heart and down into the vena cava where the filter was located. These contraptions look like daddy’s long legs with little hooks on each foot to hold them in place in the vein. Where the insect’s body would be located was a small hook. Parkhurst used a small grasping instrument to grasp the hook and pull the filter up through the vena cava and out through the small incision in the patient’s neck. Parkhurst then inserts small balloons that he inflates to reopen the thread-like flow through the narrowed vena cava. He then placed a stent to keep the vessel open. He continued this process along the primary vein of each leg. The procedure took six hours and required nine stents, but in the end there was good blood flow between the legs and the heart.
The first time the patient got up after this procedure, he was amazed. The dizziness was gone. It’s been four months and it hasn’t come back. No weak legs, no dizziness, no falls. His feet are still numb, but he can live with that as long as they stay on the ground and he stays upright.
Slief is humble about making this obscure diagnosis. There are only a handful of case reports in the medical literature. Still, Slief told me, you wonder if this might happen more often than reported. He’s definitely looking for it.
Lisa Sanders, MD, 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 to [email protected].