1. Aorta/IVC
Abdominal Vascular

2. Aorta Size
Portions:
Proximal : superior to or at the level of the celiac axis, measures 2-3 cm
Middle: below the celiac axis, above the renal arteries, measures cm
Distal: just above the bifurcation, measures 1.1 to 2.0 cm
Iliac arteries: measure cm
Tapers from superior to inferior

3. Pathology
Ectasia: when the abdominal aorta does not taper as it normally does but “kinks”
is not dilated to the point of aneurysm
usually occurs anteriorly and to the left

4. Coarctation of the Aorta
Coarctation: narrowing of the aorta
congenital condition
narrows in the
area where the
ductus arteriosus
inserts

5. Coarctation of the aorta
Clinical Findings:
Hypertension resulting from decreased kidney perfusion
causes abnormally high blood pressure in the arms
Decreased lower extremity pulses
Lower extremity ischemia

6. Aorta Aneurysm
Definition: a localized dilatation of the abdominal aorta exceeding the normal diameter by more than 50 percent
Artery is aneurismal if dilated segment is 1.5 times greater is size than the adjacent normal segment
Extent
Focal – localized segment
Diffuse – longer segment .

7. Pathophysiology of the Vascular System
Vascular Abnormalities
Arteries
Arteriosclerosis: disease of the arteries; the walls lose their elasticity and become hardened
Aneurysm
1. Atherosclerosis – Most common cause which are fat deposits beneath the intimal layer causing atrophy of underlying tissue
2. Trauma – Can cause an aneurysm or damage to both the the artery or the vein by forming an arteriovenous fistula
3. Congenital – Abnormalities present at and existing from the time of birth

8. Pathophysiology of the Vascular System
Aneurysm (continued)
4. Infections – such as syphilis and mycobacterium (microorganisms that can cause TB and leprosy)
Aneurysms can be classified into 2 categories:
True – localized dilatation of an artery due to weakness of the wall
False – wall of the blood vessel ruptures and blood escapes and is retained by surrounding tissues
(pseudoaneurysm)

10. Pathophysiology of the Vascular System
True Aneurysm
Types
Fusiform
Dissecting
Saccular
Mycotic

11. Pathophysiology of the Vascular System
Fusiform
Most Common
Dilatation of the entire circumference of the vessel giving it a baloonlike appearance
All three layers remain intact
Saccular
Rare and localized weakness that causes a saclike bulge in a portion of the wall
May also be associated with Berry Aneurysms

12. Fusiform Aneurysm

13. Longitudinal Image AAA

14. Thrombus in aneurysm
Image shows the large amount of intraluminal thrombus (T) commonly found in aneurysms of the aorta and iliac arteries.  The patent lumen is indicated by the red arrow.

15. AAA containing Thrombus
Echogenic area seen within the AAA is thrombus

17. Types of Aneurysms Saccular Rare localized weakness that
causes a saclike bulge in a portion of the wall
Usually affects the left lateral portion of distal abdominal aorta
May also be associated with Berry Aneurysms

18. Saccular Aneurysm

19. of aneurysm in the brain once it has formed it is likely to rupture,
Berry Aneurysm
Intracranial Berry aneurysm, also known as a saccular aneurysm, is a sac-like outpouching in a cerebral blood vessel
most common kind
of aneurysm in the brain
once it has formed
it is likely to rupture,
causing a stroke

21. Mycotic Aneurysm
Definition: is a localized, irreversible arterial dilatation due to destruction of the vessel wall by infection
develop either when a new aneurysm is produced by infection of the arterial wall or when a preexisting aneurysm becomes secondarily infected
majority of mycotic aneurysms are caused by bacteria
may be a true or false aneurysm, involving all layers or only a portion of the arterial wall
may be solitary or multiple

22. Mycotic aneurysms can occur anywhere in the body
31 % abdominal aortic
38 % femoral
8 % superior mesenteric
5 % carotid
6 % iliac
7 % brachial

23. Mycotic Aortic Aneurysm
Aortogram of the supra celiac aorta with distal runoff. Double open arrow indicates saccular aneurysm, curved arrows point to right and left renal arteries, and arrowheads outline superior mesenteric artery.

24. Arterial Dissection
Definition: tear in the intimal lining of the vessel wall
Most commonly, such deterioration is associated with high blood pressure
False lumen created between intima and media
As the dissection advances, it can close off the points at which one or more arteries branch off from the aorta, blocking blood flow

25. In an aortic dissection, the inner layer (lining) of the aortic wall tears, and blood surges through the tear, separating (dissecting) the middle layer from the outer layer of the wall. As a result, a new, false channel forms in the wall.

26. Dissecting Aneurysms May extend from aortic valve to abdominal aorta
Most common in thoracic aorta (Ascending 65 %)
Dissection Classification: DeBakey system
Type I - Originates in ascending aorta, propagates at least to the aortic arch and often beyond it distally.
Type II – Originates in and is confined to the ascending aorta.
Type III – Originates in descending aorta, rarely extends proximally but will extend distally

27. Sonographic Appearance
Distinguishing characteristic: membrane that divides the vessel lumen into two compartments
Membrane moves freely with arterial pulsations if both lumens are patent and membrane is thin
Diameter in area of dissection usually larger than normal surrounding vessel

28. Causes of Dissection associated with hypertension up to 80 %.
result of chest trauma
Connective tissue disorders
Marfan syndrome: genetic disorder of the connective tissue

32. Dissecting Aneurysm showing intimal flap

33. Pathophysiology of the Vascular System
Pseudoaneurysm (false)
Tear in the vessel wall
Blood escapes into surrounding tissue
They do not have a wall; surrounded by clot

35. Pseudoaneurysm
Neck of the Pseudoaneurysm

36. To and Fro Doppler Waveform
Biphasic

38. Pathophysiology of the Vascular System
Abdominal Aortic Aneurysm (AAA)
Usually found as a incidental finding from another imaging modality ie. CT Scan, U/S, Radiograph
May present as a abdominal bruit
Most common in males over the age of 50
Focal dilatation of the aorta; measures equal to or greater than 3cm in the AP diameter (outer wall to outer wall)
97% occur below the level of the renal arteries

39. Pathophysiology of the Vascular System
AAA measurements
3-4 cm yearly follow up exam
5cm surgical consult
>6cm risk of impending rupture
Symptoms
Usually asymptomatic
Pulsatile mass and or pain in the back
Dissecting AAA- excruciating chest pain that radiates to the back. 15% c/o no pain
Ruptured AAA- excruciating abdominal pain, shock, and expanding abdominal mass

40. Risk of Rupture Risk of Rupture (5 year) 7 cm or larger : >75%
< 5cm:3 % risk over 10 years
Most expand at a rate of 2-4 mm/year

41. Rupture of AAA Acute: need immediate surgery > 50 % mortality rate
Chronic: if leak is contained in surrounding tissue
Demonstration of retroperitoneal hematoma = direct evidence of aortic rupture
Sonographically hematoma is:
Hypoechoic
Unilateral or asymmetric
May displace ipsilateral kidney

42. Acute Aortic Rupture
Aortic rupture. Longitudinal color Doppler image of the abdominal aortic aneurysm demonstrates an active leak of blood (arrow) on the posterior aspect of the aorta (red color signal extending outside the lumen of the aorta). Hypoechoic areas (arrowhead), also secondary to the aortic rupture, are seen within the mural thrombus.

43. Chronic Ruptured Aneurysm
Transverse image demonstrates rupture of an aortic aneurysm (red arrows) while the red arrowheads indicate the intact aortic wall.

44. Pathophysiology of the Vascular System
Treatment
Endograft
Aortoiliac graft bypass
Aortobifemoral graft bypass

45. Grafts can be anastomosed
either
end to end or
end to side manner

46. Sonographically: Grafts are echogenic and have a textured appearance
Aorto-bifemoral graft

47. Endograft
Definition: a fabric covered metallic stent or “endograft” is inserted into an abdominal aortic aneurysm without making an incision on the abdomen
an incision in the femoral artery at the level of the groin
using x-ray while passing the device into the aneurysm
stringent anatomical criteria must be met to allow for success
iliac arteries too small or too atherosclerotic
aorta above the aneurysm is too large

48. Transverse view of AAA (cursors) Color show two inferior ends of
an endovacular stent in posterior aspect of aneurysm. Note: no color flow outside of stent

49. Aortoiliac/Aortobifemoral Bypass
Definition: grafts are placed near a section of the blood vessel that is blocked or narrowed. The graft creates a path so that blood can move around the blockage. In this case the grafts are placed on the aorta and the iliac or femoral arteries
Most bypass surgery involves a traditional, open incision

50. Sonographic Evaluation
Document proximal and distal anastomosis for stenoses, aneurysm or pseudoaneurysm
Document flow and velocity through the graft
Document waveforms and velocities in vessels just beyond distal anastomosis
Document any echogenic material within graft lumen(thrombus)
Document any fluid collections in peri graft region

51. Graft Leak

52. Aorta
Scan Procedure

53. Pathophysiology of the Vascular System
Ultrasound Examination of the Aorta
Patient must be in a basal state at least 6 hours prior to the study to reduce overlying bowel gas
3.5 5 MHz sector or linear transducer
Longitudinal and transverse images of the aorta from the diaphragm to the iliac arteries must be obtained. The AP diameter must be measured in the longitudinal view

54. Scan Procedure AAA measurements:
AP measurement in longitudinal and transverse views. Measure transverse diameter.
Measurements are outer wall to outer wall.
If AAA is found:
obtain coronal views of right and left kidneys for renal length
 check for renal artery involvement
measure from SMA to aneurysm if origin of renal arteries cannot be visualized

55. Measurement of AAA Make sure vessel tortuosity does not cause
Exaggerated measurement
of AAA
NOTE: deviation of tortuous aorta to left of
spine—most common presentation

56. Measurement Aorta measurement in the coronal plane-outer to outer
Aorta measurement in the transverse plane-outer to outer

57. Doppler Analysis
Normal flow pattern: plug flow
High resistive

58. Iliac Artery Aneurysm

59. Iliac Aneurysms 80-90% are in men over the age of 70
Most asymptomatic but rarely may thrombose,
embolize or even rupture
Usually found incidentally or in association with
AAA (CT/ US/ MRI)
Common iliac 10 x more common than internal
Rarely occur in external
Right twice as common than left
Usually involve proximal or distal portion of vessel
Rupture rare if less than 3cm

60. Iliac Artery Aneurysms
Most associated with AAA
Not associated called: Isolated
Uncommon
½ rupture with
vague abdominal or
pelvic symptoms making
mortality high—up to 60%

61. Pathophysiology of the Vascular System
Arteriovenous Malformation
Abnormal connection between the artery and vein
High arterial pressure causes the blood to go directly from the arteries to the veins
Can be congenital (rare), acquired (biopsy, trauma, surgical procedure, and ruptured aneurysm) or idiopathic
Patients are usually asymptomatic but may present with hematuria, abdominal pain or bruit, HTN, and CHF

62. Pathophysiology of the Vascular System
Ultrasound Findings of AVM
A pseudoaneurysm may be seen
Duplex Doppler evaluation will show a high turbulent velocity arterial-venous signal
A peripheral thrombus may be seen

63. Great Vessels
Inferior Vena Cava

64. Waveform
Continuous waveform with respiratory variations; become more pulsatile as it empties into the right atrium.
Best imaged with a slight cranial-caudal sweep in the longitudinal plane with the patient in deep inspiration
Thrombosis can cause the IVC waveform to appear monophasic with high velocities ("choppy" appearance).
Evaluate for thrombus in the renal veins as well.
If a surgical shunt is present, be sure to check the patient's history to find out the specific type of shunt (portal/cava or mesenteric/cava) is in place

65. IVC Waveform demonstrating both respiratory and cardiac
pulsations—Described as “saw-tooth”

66. IVC Location & Size
The IVC is posterior to the main portal vein, caudate lobe and head of the pancreas
The Right Renal Artery is posterior to the IVC
IVC changes with respiration and valvsalva maneuver
Upper limits of its normal diameter is 3.7cm during full inspiration
Inspiration – increases in size
Expiration – decreases in size
Valsalva – increases in size

67. IVC Pathology

68. Pathology IVC Dilatation Occurs with
Faulty tricuspid valve: allows blood to reflux through right atrium into IVC-
Right Ventricular failure (CHF, hypertension)
IVC fails to collapse with expiration
Duplex Doppler evaluation can be helpful

69. IVC Dilatation
2-year history of congestive heart failure the inferior vena cava was enlarged (Fig. 2B) and failed to show any respiratory variations in diameter.

70. IVC Congenital Anomalies of the IVC
Most occur at or below level of renal veins
Often associated with other cardiac malformations
Absence of the IVC is rare
Major anomalies relate to the embryologic development at 6-10 weeks gestation
Deviation from normal embryogenesis can result in: Duplication and Transposition

71. Duplication Duplication of the IVC A left IVC is present
A right sided IVC is also present
the left IVC usually is smaller than the right, although they can be equal in size
the left IVC typically empties into the left renal vein and, subsequently, into the right IVC

72. Duplication of IVC
Transverse lower abdominal scan demonstrates a left-sided IVC adjacent
to the aorta in addition to a normal right sided IVc

73. Congenital Abnormalities
Transposition of the IVC %
IVC originates on the left side of the pelvis instead of the right; below the Renal Veins
Drains into the Left Renal Vein and then crosses anteriorly over the aorta to a normal left sided upper IVC above the Renal Veins

74. Transposition Transverse abdominal CT image with enhancement
of the left-sided inferior vena cava (in red).

75. IVC Tumors Tumors may involve the IVC in different ways:
Extrinsic Compression- compression from an outside source
Direct invasion from adjacent neoplasm
Venous extension of tumor from a vein draining in to the IVC (renal cell CA)
Primary tumor of the IVC wall
Most common tumor is by extrinsic compression
Hepatomas; adrenal; pancreatic head tumors
lymphadenopathy

76. IVC Tumors
Primary tumors are rare but is most likely to be leiomyosarcomas
Appears as a large intraluminal mass with mid-level echoes on ultrasound
Intravenous extensions (secondary tumors) are commonly seen with hepatomas and renal cell carcinoma
Hepatomas invade the IVC and Right Atrium through the hepatic veins
Renal Cell Carcinoma invades the IVC through the renal veins
Primary tumor may be identified by following thrombus formation 76

77. IVC Tumor Thrombus

78. Thrombosis IVC Thrombosis May be partial or complete obstruction
Compete is life threatening
Patients present with leg edema, lower back pain, pelvic pain, renal and liver abnormalities
Non-tumoral clots can extend from the iliacs or renal veins. Thrombus appears as a homogenous echogenic mass in the lumen of the IVC