Integrating surveillance and surgery to improve aortic care 

Thoracic aortic aneurysms (TAAs) may originate and progress in the absence of symptoms until the occurrence of a catastrophic event, such as a dissection or rupture.

The Cardiothoracic Surgery Department at Penn Medicine Lancaster General Health is taking a proactive approach to early intervention as a pathway to preventing the high mortality rates associated with emergent cases.

“We’re translating our experience with treating high volumes of emergent cases into a program designed to prevent them,” explains Jeremy McGarvey, MD, a cardiothoracic surgeon at Penn Medicine Lancaster General Hospital. “By focusing on surveillance and prevention, our goal is to save lives and improve long-term outcomes for patients with aortic disease.”

Finding an often-invisible problem

A thoracic aortic aneurysm is a dilated region of the aorta that can occur as a consequence of one or more conditions, including:

• Atherosclerosis: Hardening of the arteries that weakens the aorta over time is the most common cause, especially in older adults.
• Hypertension: Stress on the aortic wall from chronic high blood pressure can cause bulges, potentially leading to dissections.
• Genetic disorders: Connective tissue disorders, such as Marfan syndrome, can result in damage to the aortic wall.
• Structural or functional defects: These anomalies of the aortic valve can adversely affect blood flow and cause gradual dilation.
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Not all changes in the aorta (normally around 22 mm in diameter) require intervention. Aortic ectasia describes a widening of the aorta by less than 50 percent of its diameter. By contrast, TAAs involve expansion of a weakened region to 4.5 cm, with anything over 5.5 cm requiring surgery. However, interpretation of these measurements may fail to account for nuances in patient-specific factors.

“People come in different shapes and sizes and bring unique risk factors that need to be accounted for,” says Dr. McGarvey. This means that a 4.5-cm aneurysm in a 6’11” male is likely insignificant, whereas it may require an operation in a 4’11” female. “Recent incorporation of size indexing and other risk factors has allowed levels of diagnostic nuance and flexibility that weren’t previously available.”

Timely and accurate diagnosis of TAAs is extremely difficult.

Although extraordinarily rare (less than 1 percent worldwide prevalence according to a 2022 study), TAAs can form and grow asymptomatically until dissecting and/or rupturing. In many cases, TAAs are found through imaging performed for unrelated reasons, including lung cancer screening or evaluation during a trip to the emergency room.

Such images can offer sufficient evidence to initiate a cascade of events within Lancaster General Health’s aortic aneurysm surveillance program. “Identifying a potential issue leads to a nurse navigator having a patient provider schedule more focused diagnostic imaging,” explains Dr. McGarvey. This includes targeted CT, MRI, and echocardiograms that also allow closer inspection of the aortic valve, deficiencies in which often coincide with TAAs.

In some cases, individuals may not have an aneurysm requiring surgery, but valve insufficiency that does.

Regardless of the circumstances, there’s a fine line between determining when a TAA warrants a watch-and-wait approach and when action is required. Those decisions rely on the dynamics surrounding a patient’s life and the experience of the surgeon.

Managing risk by minimizing it

Dr. McGarvey emphasizes the critical importance of a structured surveillance program in identifying and tracking at-risk patients. “Our goal is to remove the guesswork from decisions by primary care providers and specialists concerning whether and when to refer patients,” he explains.

Their program involves a semi-automated algorithm that incorporates changes in national guidelines to allow for a seamless approach to determining which patients require intervention. “This type of surveillance also enables us to decide when a more hands-on approach might benefit patients based on their status at any given moment.”

In the case of TAAs, data and experience drive decisions regarding elective surgery, especially in patients living normal lives absent any outward symptoms. Deciding whether and when to perform an elective procedure is a matter of balancing the risk of waiting and watching with that of an operation to fix the problem.

Another element in the decision-making process is the impact on a patient’s life and livelihood. For patients under surveillance whose professions require even moderate levels of strenuous activity, the risk of waiting and watching can be significant.