Aneurysms: Causes, Classification, and Diagnosis

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the main cause of an aneurysm?

Narrowing of the blood vessel

Inflammation of the blood vessel wall

Blockage of the blood vessel

Weakening of the blood vessel wall (correct)

What is the normal diameter of the ascending aorta?

4 cm (correct)

5 cm

6 cm

3 cm

What type of aneurysm occurs when there is a tear through all three layers of the wall and a periaortic collection is formed?

Dissecting aneurysm

False aneurysm (correct)

Fusiform aneurysm

True aneurysm

What is the most common location of thoracic aortic aneurysms?

Ascending aorta Signup and view all the answers

What is the age range with the highest predilection for thoracic aortic aneurysms?

65 years Signup and view all the answers

What is the term for an aneurysm that involves only a portion of the aortic wall?

Saccular aneurysm Signup and view all the answers

What is the term for an aneurysm that involves the entire circumference of the aorta?

Fusiform aneurysm Signup and view all the answers

What is the term for a dissecting aneurysm?

A tear through the tunica intima Signup and view all the answers

What is the most common cause of Abdominal Aortic Aneurysm?

Atherosclerosis Signup and view all the answers

What is the gold standard for the diagnosis of aneurysms and dissections?

CT/CTA Signup and view all the answers

What is the primary advantage of using Ultrasound in diagnosing Abdominal Aortic Aneurysm?

No radiation exposure Signup and view all the answers

What is the term for the separation of the aortic intima with a tear in it, communicating with the true lumen?

Dissection Signup and view all the answers

What is the primary complication of Abdominal Aortic Aneurysm?

Rupture Signup and view all the answers

What is the purpose of pre-operative assessment of AAA?

All of the above Signup and view all the answers

What is the term for the curvilinear calcification seen on plain film in abdominal aortic aneurysm?

Mural calcification Signup and view all the answers

What is the alternative to CT/CTA in patients with impaired renal function or allergy to contrast?

MR/MRA Signup and view all the answers

Study Notes

Aneurysms

An aneurysm is an abnormal dilatation of a blood vessel caused by the weakening of the blood vessel wall.

Causes of Aneurysms

Atherosclerosis
Hypertension
Inflammatory/Arteritis
Connective Tissue diseases (e.g. Marfan's, Ehlers-Danlos)
Smoking
Infections
Pregnancy
SLE
Trauma

Maximum Normal Aortic Diameter

Ascending aorta: 4 cm
Descending aorta: 3 cm
Abdominal aorta: 2 cm

Classification of Aortic Aneurysms

True aneurysms: all three layers of the wall are affected and the ballooning is contained in them
False aneurysms: tear through all three layers of the wall and a periaortic collection is formed, contained by the extra vascular connective tissue
Dissecting aneurysms: tear through the tunica intima, causing blood collection in between the layers
True aneurysms can be further divided into:
- Fusiform aneurysm: circumferential involvement of the aorta
- Saccular aneurysm: only a portion of the wall is involved

Thoracic Aortic Aneurysm

Aneurysmal dilatation of the ascending, descending, or arch of the aorta
Anatomical classification:
- Aneurysm of sinus of Valsalva: congenital, syphilis
- Ascending aorta: atherosclerosis, Marfan syndrome, Ehlers-Danlos syndrome, syphilis, Mycotic
- Arch of aorta: atherosclerosis
- Descending aorta, aortic isthmus: post-traumatic aneurysm, atherosclerosis

Clinical Presentation of Thoracic Aneurysms

Substernal, back, and/or shoulder pain
Dysphagia
Stridor
Dyspnea
Voice hoarseness (due to recurrent laryngeal nerve compression)

Imaging of Thoracic Aneurysms

CHEST X-RAY: widening of mediastinal silhouette, enlargement of aortic knob, displacement of trachea/esophagus from the midline, calcification in cases caused by atherosclerosis
CT/CT Angiography: gold standard for diagnosis of aneurysms and dissections, measures maximum size, and monitors diameter change over time
MR/MRA: alternative to CT/CTA, especially in patients with impaired renal function and allergy to contrast
Aortography: rarely used nowadays, precise definition of anatomy of aneurysm and great vessels

Causes of Abdominal Aortic Aneurysm

Atherosclerosis (70-90%)
Traumatic (15-20%)
Congenital (2%)
Syphilis
Mycotic
Inflammation of media and adventitia (Takayasu arteritis, Rheumatic fever, RA, AS, Reiter syndrome)

Imaging of Abdominal Aortic Aneurysm

Plain Film: curvilinear mural calcification
Ultrasound: advantages include availability, speed, low cost, and no radiation, disadvantages include affected view in obese patients, bowel gases, and proximal iliac arteries, findings include focal dilatation beyond normal and any increase in size of aorta that travels distally is abnormal

Complications of Abdominal Aortic Aneurysm

Rupture (25%)
Peripheral embolization
Infection
Spontaneous occlusion of aorta
Pseud-aneurysm
Compression of adjacent structures

Pre-operative Assessment of AAA

Maximum diameter of the aneurysm
Proximal and distal extent of aneurysm
Assessment of iliac and renal arteries
Peri aneurysmal fibrosis
Congenital variation: accessory renal artery, retro aortic course of left renal vein
CT/CTA is required for assessment, US alone is not enough

Aortic Dissection

Separation of the aortic intima with a tear in it, communicating with the true lumen
True lumen: inside the intima
False lumen: outside the intima

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz covers the definition, causes, and classification of aneurysms, including the abnormal dilatation of blood vessels and their underlying factors. It also touches on the normal diameter of different aortic segments.