Aortitis overview

# Overview
Aortitis is the inflammation of the aortic wall.  The disorder is rare, but potentially life-threatening.  Aortitis may occur at any age. Aortitis is classified according to the cause into 2 groups: inflammatory and infectious.  Life threatening causes of aortitis include bacteremia and mycotic aneurysm.  Common causes of aortitis include ankylosing spondylitis, giant cell arteritis, Takayasu arteritis, and syphilis.  Aortitis must be differentiated from aortic dissection, intramural hematoma, and penetrating atherosclerotic ulcer. If left untreated, infectious aortitis is associated with a high rate of aortic rupture and subsequent mortality.  Aortitis due to either giant cell arteritis or Takayasu arteritis has a high rate of recurrence despite therapy. Common complications of aortitis include: aortic aneurysm, aortic rupture, aortic dissection, thrombus formation in the aortic lumen, and hypertension.  The prognosis of infectious aortitis is generally poor.  Prognosis of isolated aortitis and aortitis associated with rheumatic diseases is generally good with prompt diagnosis. Symptoms of aortitis include back pain, fever, abdominal pain, chest pain, shortness of breath, and fatigue. Common physical examination findings of aortitis include abnormal heart sounds, hypertension or hypotension, a difference in blood pressure between both arms, and either reduced or absent pulses. CT scan with the administration of iodinated contrast (CTA) may be diagnostic of aortitis.  Magnetic resonance angiography (MRA) is the noninvasive imaging of choice for aortitis.  On transthoracic and transesophageal echocardiogram, aortitis is characterized by aortic wall thickening. Early antimicrobial therapy with broad spectrum coverage is indicated in infectious aortitis.  The preferred agents include either Cefotaxime, Ciprofloxacin, penicillinase-resistant penicillins, or Vancomycin. Surgical debridement is recommended among patients with gram-negative rod aortitis.

# Classification
Aortitis may be classified according to the cause into 2 groups: inflammatory and infectious.

# Pathophysiology
Aortitis is inflammation or infection of the aortic wall. On microscopic histopathological analysis, extensive intimal and adventitial fibrosis and  scarring with luminal narrowing are characteristic findings of aortitis due to Takayasu arteritis.  Extensive medial inflammation and necrosis are characteristic findings on microscopic histopathological analysis of aortitis due to giant cell arteritis. The majority of cases of infectious aortitis are due to bacteria seeding through a segment of the aortic wall with existing pathology via the vasa vasorum.

# Causes
Life threatening causes of aortitis include bacteremia and mycotic aneurysm. Common causes of aortitis include ankylosing spondylitis, giant cell arteritis, Takayasu arteritis, and syphilis.

# Differential Diagnosis
Aortitis must be differentiated from aortic dissection, intramural hematoma, and penetrating atherosclerotic ulcer.

# Natural History, Complications and Prognosis
If left untreated, infectious aortitis is associated with a high rate of aortic rupture and subsequent mortality.  Aortitis due to either giant cell arteritis or Takayasu arteritis has a high rate of recurrence despite therapy. Common complications of aortitis include: aortic aneurysm, aortic rupture, aortic dissection, thrombus formation in the aortic lumen, and hypertension.  The prognosis of infectious aortitis is generally poor.  Prognosis of isolated aortitis and aortitis associated with rheumatic diseases is generally good with prompt diagnosis.

# Diagnosis

## History and Symptoms
Symptoms of aortitis include back pain, fever, abdominal pain, chest pain, shortness of breath, and fatigue.

## Physical Examination
Common physical examination findings of aortitis include abnormal heart sounds, hypertension or hypotension, a difference in blood pressure between both arms, and either reduced or absent pulses.

## Laboratory Findings
Laboratory findings consistent with the diagnosis of aortitis include elevated erythrocyte sedimentation rate and C-reactive protein.

## CT
CT scan with the administration of iodinated contrast (CTA) may be diagnostic of aortitis.  Findings on CT suggestive of aortitis include thickening of the aortic wall and periaortic inflammation.  CT scan may also be helpful in the diagnosis of the complications of aortitis.  Findings on CT suggestive of complications of aortitis include aortic and arterial calcification, stenotic lesions of the aorta, aortic aneurysm, and luminal thrombus.

## MRI
Magnetic resonance angiography (MRA) is the noninvasive imaging of choice for aortitis.   On MRA, aortitis is characterized by stenoses at multiple levels,
mural thrombi, and thickening of aortic valve cusps.

## Echocardiography and Ultrasound
On transthoracic and transesophageal echocardiogram, aortitis is characterized by aortic wall thickening. Echocardiography may also be helpful in the assessment of aortic root and aortic valve involvement in aortitis. Findings on ultrasound suggestive of Takayasu arteritis include extensive concentric thickening of affected aorta and branch vessels.  Findings on ultrasound suggestive of giant cell arteritis include a "halo" sign, aortic wall thickening, and small aneurysms.

# Treatment

## Medical Therapy
Early antimicrobial therapy with broad spectrum coverage is indicated in infectious aortitis.  The preferred agents include either Cefotaxime, Ciprofloxacin, penicillinase-resistant penicillins, or Vancomycin.

## Surgical Therapy
Surgical debridement is recommended among patients with gram-negative rod aortitis.