Penetrating aortic ulcers account for 2–7% of acute aortic syndromes, and thus it is crucial to recognize the predisposition of an aortic dissection upon a patient’s presentation. Atheromatous ulcers develop in patients with advanced atherosclerosis. Initially, the lesions are confined to the intimal layer however they can penetrate through elastic intima and into the media. Once a penetrating atheromatous ulcer (PAU) is formed, the ulcer may remain quiescent or progress to acute processes like dissection or aneurysm formation. PAU’s also tend to have a scarcity of symptoms which is in contrast to the classic symptoms associated with dissections including severe back or chest pain or aortic regurgitation5. Given this patient’s risk factors and history of abdominal aortic aneurysm, right iliac artery aneurysm, hypertension, and hyperlipidemia, the threshold for further workup became even lower for this patient. The risk of aortic rupture is significantly higher in patients with PAU, and medical management often is ineffective in ascending aortic pathology and surgery is often indicated. Thus, PAUs are considered precursors of life-threatening aortic dissections, and are rarely located in the ascending aorta.
Life expectancy of patients affected by PAU has not been noted to exceed ten years after diagnosis, which reinstates the severity of disease in these patients6, 7. Patients have also been noted to have a concurrent abdominal aortic aneurysm in up to 60% of patients with abdominal PAU8, 9. Stanson et. al and Cooke et al. have both illustrated that PAU requires aggressive surgical treatment of symptomatic patients since conservative medical therapy had often times led to recurrence or worsening of symptoms and propensity to rupture10,11. An early study by the Yale group found that 40% of patients who were primarily treated conservatively needed emergency interventions for rupture12. The Stanford group again demonstrated that progression with PAU occurred in 48% of cases, and a strictly conservative regimen led to 10% mortality within a mean of 9.3 days3. These findings were accepted as the mainstay of treatment unless the risk associated with a patient’s comorbidities outweighed the benefit of surgical intervention. These conclusions support the recommendation for surgery. However, in some cases, studies have also shown that many PAU have been managed non-operatively. Hussain et. al argues that a confined intramural hematoma is not exposed to the turbulent aortic flow that one might find in a double lumen and thus potentially more likely to remain stable13. Kazerooni et. al describes patients with typical symptoms that had abnormal imaging including chest radiograph showing an enlarged thoracic aorta, and CT scans showing intramural hematoma (n = 16), focal ulcer (n = 15), displaced intimal calcification (n = 13), pleural and/or extrapleural fluid (n = 7), mediastinal fluid (n = 4), and a thick or enhancing aortic wall (n = 6). The study demonstrated that by comparing films and treating patients surgically (n = 7) and conservatively (n = 9), eight of the nine patients treated conservatively were asymptomatic after appropriate control of blood pressure14. However, it is still important to determine the threshold of an aortic ulcer being present and the verge of it dissecting, which becomes solely surgical when a patient is hemodynamically unstable.
The risk stratification of the presented patient required serial imaging to quantify the rate of progression, if any, as well as determining the etiology and method of resolution of the patient’s right hand weakness. Risk factors for progression are thought to be of various groupings, including simply symptom onset, as well as depth and diameter of PAU. Ganaha et al. identified both the maximum PAU diameter and maximum PAU depth (21.1 ± 8.0 mm and 13.7 ± 4.2 mm), as well as rapid increase of aortic diameter and hemodynamic instability as indications for immediate surgery3. Given our patient’s risk of MACE and comorbidities, it was extremely integral to weigh out advantages and disadvantages. The patient’s resolution of symptoms did not necessarily imply lesion stability, and thus it was integral for the patient to have follow up imaging to assess for worsening disease as described above. While the patient was admitted in the intensive care unit (ICU), serial imaging did not show progression of PAU and thus the recommended interval of follow up imaging was prolonged upon discharge from the hospital. The most recent interval for imaging has been prolonged to one year, with most recent CT angiogram of the chest in March 2020 again showing a focal outpouching in ascending thoracic aorta. Patient will return for follow up imaging in March 2021.
If this patient did not have the comorbidities they did, surgical intervention would have prevailed as the primary treatment of choice. Thoracic endovascular aortic repair (TEVAR) is especially effective as an intervention modality. This procedure usually involves a stent delivered through a sheath introduced into the common femoral artery or common iliac artery into the abdominal aorta and further into the level of the thoracic aorta. Brinster et al. showed that this approach in 21 patients all presenting with uncontrolled pain associated with PAU or radiologic evidence of impending rupture, or both. Sixteen of these patients had an acute presentation with symptoms being present for less than fourteen days15. All patients treated with endoluminal graft placement had 100% relief of their symptoms with no operative mortalities. This is especially notable since many patients who have previously been managed conservatively often can have disease progression. Conservative management involves adequate blood pressure control with normalization and left ventricular ejection fraction (LVEF) reduction as they are the main determinants of dissection extension and rupture. Beta blockers have been shown to decrease mortality from 67–95%16, and for this reason are usually the agents of choice when initiating blood pressure management or titrating medications.
The patient presented in this case report was one of the 5–15% of penetrating aortic ulcers located in the ascending aorta. This is a rare finding, and management remained non-conservative after close following.