Within weeks, an otherwise healthy patient in his late 60s went from regularly running 3 to 5 miles to being unable to walk up the stairs, and eventually to not being able to move his left leg at all.

His general practitioner sent him to a neurologist, who ordered a spinal MRI that showed abnormal vessels within the spinal canal in addition to spinal cord swelling. The neurologist referred the patient to Johns Hopkins Medicine, where he met with Rafael Tamargo, who specializes in open vascular surgeries. Tamargo recommended a spinal angiography, a procedure that advances a catheter from the femoral artery (at the groin) to each of the segmental small arteries that feed the spinal cord. A contrast dye is then injected, and the results are viewed on a large monitor.

L. Fernando Gonzalez performed the spinal angiogram, which revealed the patient had a spinal arteriovenous fistula (AVF), a vascular abnormality characterized by irregular connection between spinal artery and vein, increasing the spinal cord venous pressure and causing cord swelling. He also saw that the connection between artery and vein was not in its usual location in the wall of the dura mater (which protects the spinal cord) but outside this layer. “It was not in the regular space that we expect to find it,” says Gonzalez. “It was outside of the spine.”

Tamargo runs a weekly cerebrovascular conference to review patients’ clinical histories and imaging. At that meeting, the neurosurgeons agreed that the fistula was appropriate for embolization, and an endovascular approach — advancing a tiny catheter (0.4 mm) directly into the abnormal connection and injecting a liquid in order to close it — would be best.

However, access to the fistula would risk damaging blood vessels near the artery that supply blood to the spinal cord. Before treating the patient, an angiogram was needed to find the exact location of the fistula and pinpoint the blood vessel anatomy of the spine, spinal cord and fistula, says Carlos Pardo, the Johns Hopkins Medicine neurologist who diagnosed the patient.

Within hours after the procedure, the patient was able to lift his leg, and before long he was walking. MRIs and an angiogram several months later showed that the swelling had completely regressed. A spinal angiogram three months later showed that the fistula was gone.

The patient began physical therapy at Kennedy Krieger Institute and has continued improving. Within months, he ran and walked a 5K race. He now has sufficient mobility to maintain the 20-acre property where he lives.

However, the nerve damage from the fistula is permanent, and the patient has issues with numbness, balance and gait.

“It’s just a different way of life,” says the grateful patient. “Dr. Gonzalez told me that from day one. I take things one step at a time.”