Chapter 11 – Blood Vessels:Vessel :Congenital Anomalies

Question 1

When do variants of the usual anatomic pattern of vascular supply become important?

Answer 1

during surgery when a vessel in an unexpected location is injured.

Variations
in the normal coronary artery anatomy are also extremely important to the cardiac surgeon or
interventional cardiologist. [5,] [6]

Question 2

Among the other congenital vascular anomalies, three are
particularly significant, though not necessarily common:

Answer 2

• Developmental or berry aneurysms
• Arteriovenous fistula
• Fibromuscular dysplasia

Question 3

What are developmental or berry aneurysms?

Answer 3

Developmental or berry aneurysms occur in cerebral vessels; when ruptured these can
be causes of fatal intracerebral hemorrhage

Question 4

What are Arteriovenous fistulas?

Answer 4

are abnormal, typically small, direct connections between arteries
and veinsthatbypass the intervening capillaries

Question 5

Where does Arteriovenous fistulas mostly occur?

Answer 5

They occur most commonly as

• *developmental defects** but can also result from rupture of an arterial aneurysm into an
• *adjacent vein**, from penetrating injuries that pierce arteries and veins, or from inflammatory necrosis of adjacent vessels; intentionally created arteriovenous fistulas are used to provide vascular access for chronic hemodialysis.

Question 6

Where do we intentionally create arteriovenous fistulas?

Answer 6

used to provide vascular access for chronic hemodialysis.

Question 7

When does arteriovenous fistulas become clinically significant?

Answer 7

Large or extensive arteriovenous fistulas become clinically significant
by shunting blood from the arterial to the venous circulations and forcing the heart to
pump additional volume; high-output cardiac failure can ensue.

Question 8

What is fibromuscular dysplasia?

Answer 8

is a focal irregular thickening of the walls of medium and large muscular arteries, including renal, carotid, splanchnic, and vertebral vessels.

The cause
is unknown but is probably developmental;first-degree relatives of affected individuals
have an increased incidence.

Segments of the vessel wall are focally thickened by a
combination of irregular medial and intimal hyperplasia and fibrosis; this results in
luminal stenosis, and in the renal arteries may be a cause of renovascular hypertension
( Chapter 20 ).

Vascular outpouchings (aneurysms) may develop in the vessel segments
with attenuated media and in some cases can rupture.

Question 9

Fibromuscular dysplasia is frequently manifested by what age?

Answer 9

Fibromuscular dysplasia can
manifest at any age, although it is seen most frequently in young women; there is no
association with use of oral contraceptives or abnormalities of sex hormone
expression

Question 10

Fibromuscular dysplasia has an association with use of oral contraceptives or abnormalities of sex hormone
expression.

T or F

Answer 10

False

there is no
association with use of oral contraceptives or abnormalities of sex hormone
expression