May 15, 2017
The patient, typically a middle-aged female, might have a sudden onset of high blood pressure. She might experience headaches or constantly hear the sound of her heart beating in her ears. Or she might have a history of stroke or aneurysm. Although seemingly unrelated, these symptoms can all point to the same problem: fibromuscular dysplasia (FMD), an abnormal nonatherosclerotic, noninflammatory growth of connective tissue or smooth muscle in the walls of arteries.
This disorder is relatively rare and, with symptoms mimicking those of a multitude of other health problems, it remains so mysterious that few doctors tend to think of FMD when patients present with complaints, says Elizabeth Ratchford, director of the Johns Hopkins Center for Vascular Medicine and co-director of Johns Hopkins’ multidisciplinary FMD clinic. The clinic is one of only a few centers in the country with comprehensive expertise on this condition.
“It usually takes a very high level of clinical suspicion to make an FMD diagnosis, as well as a specialist who’s familiar with seeing these cases,” Ratchford says.
Her clinic co-director is renal expert C. John Sperati. Due to the complex nature of the disease, tapping into expertise from both vascular and renal medicine is key to its diagnosis and treatment, Ratchford explains. Although FMD can affect many different arteries in the body, it tends to strike some more frequently than others, including the renal arteries and the mid- to distal portions of the carotids.
When the renal arteries are affected, a sudden rise in blood pressure can often result. FMD in the carotid arteries might lead to turbulent blood flow that some patients can actually hear. The condition could also cause headaches or other cerebrovascular complications, such as dissection, stroke, transient ischemic attack or aneurysm.
Imaging plays a pivotal role in the diagnosis of this disorder, Ratchford says; as such, colleagues in the Department of Radiology are key partners in identifying patients with this condition. For suspected cases of FMD, she and Sperati take advantage of a pre-existing order set in Hopkins’ electronic medical records system to request specific tests from radiology clinicians who are familiar with their established FMD protocol.
CT angiography (CTA) remains the gold standard for FMD diagnosis, Ratchford explains, with the condition often presenting as a “string of beads” in this imaging because affected blood vessels can repeatedly narrow and widen for an extended stretch. Once an FMD diagnosis is confirmed, patients typically undergo a more comprehensive CTA to check for additional affected vessels elsewhere in the body. “Everyone with a new diagnosis needs a ‘stem to stern’ CTA,” she says.
Imaging continues to play an important role throughout a patient’s lifelong follow-up, Ratchford says. Those patients seen through the multidisciplinary clinic will continue to come in yearly—more frequently, if necessary—to make sure that identified FMD foci aren’t worsening or that new problem areas aren’t forming.
Between visits, however, the vast majority of cases can be managed medically. Most patients take some form of antiplatelet or antithrombotic agents (low-dose aspirin is most common) to prevent clots from forming in affected arteries. ACE inhibitors and other antihypertensive therapies are also important for keeping hypertension due to restricted renal blood flow under control.
For patients whose hypertension isn’t controlled medically, surgery is a possibility, says Johns Hopkins vascular and endovascular surgeon Christopher J. Abularrage. Endovascular balloon angioplasty can break down renal septations and enlarge the renal artery lumen, sometimes curing FMD-related hypertension. For FMD-related renal aneurysms, the treatment is typically open renal artery bypass. Aneurysms elsewhere are often treated by clipping or coiling.
Although surgery is rarely necessary for FMD, Abularrage says, surgical colleagues familiar with this condition are nevertheless vital members of the team. “FMD is a complex disease that is best managed by a multidisciplinary team like the one we have here at Hopkins,” he says.
Whether her patients are managed medically or surgically, Ratchford adds, her goal is always the same: to provide the very best comprehensive care to ease their anxiety between visits. “Getting diagnosed with FMD, a condition that can lead to serious complications, can be very stressful for patients,” she says. “Based on the plan we develop to prevent problems—and the surveillance they’ll need to undergo to identify new ones—my hope is that they’ll be able to let go of worries between visits and live their lives.”