on 21-Jun-2021 (Mon)

However, IgG4-RD aneurysms have a high risk of rupture and should be surgically managed [44]

Erdheim-Chester disease (ECD) is a rare form of non-Langerhans cell histiocytosis [50–53]. At presentation, cardiovascular involvement occurs in 7% of patients reaching its peak overtime in older patients, with an overall estimated prevalence of 22% [51, 54]

Circumferential thickening of the aorta, also known as “coated aorta,” is a common feature of ECD [51, 54]. The presence of retroperito- neal fibrosis is a key element in the differential diagnosis. Ostial stenosis of the renal arteries and periaortitis can resemble LVV, particularly TAK [50]

Large vessel in- volvement can occur in the context of other forms of vasculi- tis, including Behcet’s disease. Arterial involvement is present in approximately 10% of cases of Behcet’s disease, in which both aneurysmal and stenotic complications may occur espe- cially in the pulmonary arteries, aorta, and its major branches

Occasionally, large arteries are affected in patients with polyarteritis nodosa or antineutrophil cytoplasmic antibody (ANCA)–associated vasculitis that typically involve vessels of a smaller diameter (medium and small vessels). Cogan syndrome may result in aortitis and aortic insufficiency in about 10% of cases, mimicking the pattern of vascular in- volvement in TAK [59]

In order to distinguish atherosclerotic vascular dis- ease from LVV, laboratory markers of inflammation (ESR and CRP) are often helpful, more in GCA than in TAK [17]

However, milder elevation of CRP could be linked to an inflammatory phase of atherosclerosis [17]

Inflammatory vascular symptoms such as carotidynia may be a clue to the diagnosis of LVV, particu- larly TAK [9]

The intensity, the pattern, and the distribution of 18 FDG within the arterial wall detected by PET/CT can help to dis- tinguish atherosclerosis from LVV

Second, the pattern of the lesions could help in discrimi- nating vasculitis from atherosclerosis: vasculitis lesions are usually smooth, linear, and homogeneous, while the athero- sclerosis is focal, with a characteristic “hot spot” distribution [65]

First, the intensity of FDG uptake is usually less intense in atherosclerosis than vasculitis [64]. Large vessel FDG uptake is usually graded on a 4-point scale: none (grade 0), lower (grade 1), equal (grade 2), or higher than liver uptake (grade 3). Grades 2–3 are relatively specific for vasculitis, while grade 1 (rarely 2) has been observed in atherosclerotic vessels [64]

hird, the distribution: vasculitis usually affects thoracic ascending aorta, common carotid arteries (sparing of the inter- nal and external carotid arteries), and subclavian/axillary ar- teries, while atherosclerosis generally involves iliac/femoral/ popliteal arteries, lower abdominal aorta, descending thoracic aorta, and carotid arteries, particularly with the stenosis of the carotid bifurcation and with arterial wall calcification and pa- rietal thrombosis (Fig. 2a)[64]

FMD is a non-inflammatory rare disease affecting medium-sized arteries; the most com- mon locations are typically the renal and carotid arteries, but the axillary, subclavian, and visceral vessels may also be in- volved [69]. Young females are usually affected, and inflam- matory markers are usually normal

Von Recklinghausen disease is an autoso- mal dominant disorder affecting one in 3000 individuals. The vascular spectrum of neurofibromatosis-1 (NF-1) includes an- eurysmal and stenotic disease of large, medium, and small arteries

Aortic aneurysms may be the only manifestation of hereditary disorders of the connective tissues such as vascular Ehlers-Danlos syndrome, Loeys- Dietz syndrome, or Marfan syndrome [73]

In two series of patients with suspected GCA and negative temporal artery biopsy, neurologic/neuro- ophthalmologic disorders accounted for nearly one-third of other diagnoses, including nonarteritic cerebrovascular acci- dents, nonarteritic anterior ischemic optic neuropathy (NAION), central retinal artery occlusion (CRAO), delirium, tension type headache, sarcoidosis, and Tolosa-Hunt syn- drome (i.e., painful ophthalmoparesis due to idiopathic gran- ulomatous inflammation of the cavernous sinus) [83, 84]

A new-onset or different headache, generally severe, occurs in nearly 70% of GCA cases at onset and is considered the most common reason to suspect GCA in clinical practice.

Headache is bitemporal in half of patients with GCA but can be diffuse, accompanied by scalp tenderness, or absent in up to 24% of cases [85]. Quality is generally throbbing/pulsatile, less com- monly sharp, dull, or burning; on the other hand, a thunderclap headache (i.e., a severe and unexpected headache reaching maximal intensity within seconds) suggests alternative diag- noses (e.g., subarachnoid hemorrhage, reversible cerebral va- soconstriction syndrome [RCVS]) [86].

In addition, the lack of gluco- corticoid response should prompt considering other etiologies [88], such as idiopathic thrombosis of the lateral sinus, that can mimic GCA [89], although cerebral vein thrombosis and GCA may coexist [90]

Cryptococcal and aseptic meningitis/meningoradiculitis can also mimic a GCA relapse, occurring as a complication of prolonged glucocorticoid treatment [94, 95].

The majority of patients with NAION have a congested optic nerve (“disc at risk”)and vascular risk factors [126]

High- dose corticosteroids should be initiated immediately in any patient suspected to have GCA, and the confirmatory temporal artery biopsy can be obtained within 2 weeks after starting the steroids without influencing the biopsy results [127]

Roughly 10% of vision loss from GCA is due to central retinal artery occlusion (CRAO), and therefore, inflammatory markers should be considered in elderly patients with new-onset CRAO in conjunction with a thromboembolic workup [125]

Ocular dysmotility (diplopia/ophthalmoplegia, ptosis) can occur in GCA [135, 136] and can be indistinguishable from a benign microvascular cranial nerve palsy. Therefore, GCA is a differential diagnosis for any older patient with acute onset diplopia. GCA may also resemble myasthenia gravis [137], and the two disorders may rarely coexist [138]

In the pre- antibiotic era, infectious thoracic aortitis was even more frequently related with IE, occurring in 86% of cases. 1

Mycotic aneurysms rep- resent 2.6% of all aortic aneurysms, the thoracic aorta is the least common site of occurrence. 1

In most of the reports, IA presents with an aneurysm, and it is impossible to determine if the aneurysm was already there when the infection began. 4

Infectious thoracic aortitis has a male predominance (male:female ratio = 3:1) and the mean age at diagnosis is 65 years old. If IA occurs associated to an IE, there is no gender predominance and the mean age at diagnosis is 40 years old. 1

Furthermore, there are only a few cases in the literature describing IA in the absence of an aneurysm or rupture. 3,5,6,7

Gram-positive bacteria such as the Staphylococcal species, Enterococcus species, and Streptococcus pneumonia, are the most common, and are responsible for 60% of the infections. W hen IA is associated with IE, Enterococcus species and Streptococcus pneumonia are the most common agents isolated

Gram-negative bacilli (Salmonella species in the majority of cases) are also frequent microorganisms causing aortic infection; however, they are more prevalent in infectious abdominal aortitis. 1

Fever (75%), thoracic and dorsal pain (60%), abdominal pain (20%), and chills (16%) are the most frequent symptoms. 1 Patients with no aneurysm formation are likely to be less symptomatic. 4

Possible complications of IA include aneurysm formation with sub- sequent rupture and bleeding, aortic thrombosis with distal embolization (cerebral, visceral, or limb), aortic dissection, septic embolization, aortic insufficiency, and acute coronary syndromes caused by coronary involvement. 2

However, diagnosis is frequently delayed since clinical manifestations are usually nonspecific or the first symptoms often result from expansion or rupture of an aneurysm.

Infectious thoracic aortitis should always be considered in elderly patients with atherosclerosis, history of thoracic, abdominal, or back pain, and vague symptoms such as nausea, vomiting, and fever 4

Leukocytosis and neutrophilia are present in 65% to 83% of cases. 1 Erythrocyte sedimentation rate and C-reactive protein are elevated in most of the patients. 2 Blood cultures are positive in 50% to 85% of the patients and a microorganism can be isolated from the excised aortic tissue in up to 76% of the patients.

Pretreatment with antibiotics, the absence of an infectious focus in the aortic lumen, and the presence of anaerobic microorganisms are possible causes for negative blood and tissue cultures. 1

Periaortic nodularity, change in aorta size, air in the aortic wall, and saccular aneurysm, are some radiological findings that may lead to an early diagnosis. 4 Furthermore, CT findings of periaortic density and adjacent gas collec- tion suggest an impending rupture, even if no aneurysm is present. 10

The intent of surgery is to confirm the diagnosis, control sepsis, con- trol hemorrhage (if rupture occurred), and reconstruct the arterial vasculature. 11

If surgery is not emergent (patients without impending aor- tic rupture or uncontrolled sepsis), it seems reasonable to perform a course of antibiotics for 2 to 4 weeks prior to surgery to improve local surgical conditions. 9

The antimi- crobial therapy should be extended for at least 6 to 12 weeks after surgical excision and clearance of blood cultures

Therefore, resec- tion of the infected aortic segment with in situ prosthetic graft reconstruction is, currently, the preferred method of revascularization. 14

In patients with fever and ruptured MA, EVAR should be considered only as a temporary measure to achieve hemodynamic stability. 19

However, a combination of surgical and medical therapy may lead to a survival rate of 75% to 100% before aneurysm formation, 1 and 62% after an aneurysm has formed

After aneurysm rupture, surgical mortality rates may be as high as 65%. 14 With medical treatment alone, mortality rates may reach 90%. 8

Factors apparently linked to a worse prognosis are advanced age, diagnosis delay, gram-negative bacilli infec- tion, immunodepression, thoracic location, medical treat- ment alone, and complication occurrence (such as rupture, embolization, or septic shock). 1,14,19