1. Lackawanna College Vascular Technology Program
The Vascular System

2. Circulatory System Consists of the heart, blood vessels and lymphatics
Arteries>arterioles>capillaries>
Venules>Veins
Transport gases, nutrients, and other essential substances to the tissues
Also carries waste products of cells to the appropriate excretory sight

3. Hemodynamics
Flow in peripheral arteries is regulated by vasoconstriction- restriction in the arterioles.

4. Arteries
Elastic tubes that carry oxygenated blood from the heart to the capillaries
Pulsations are in sync with the heartbeat
Walls consist of three layers

5. Arterial wall anatomy
Endothelial lining
Intima
Media
Adventitia

6. Veins
Veins are collapsible vessels that carry blood back to the heart from the capillaries
Contain valves that allow blood to propagate towards the heart with the exception of the IVC, SVC, and the CIV

7. Veins Respond to respirations
Inspiration- Vein lumen widens; the thoracic pressure increases and the abdominal pressure decreases
Expiration- Vein lumen narrows; release of pressure; the thoracic pressure decreases and the abdominal pressure increases.
Valsalva Maneuver- Vein lumen widens and blood in the lower extremity is decreased or halted and the reverse happens in the upper extrmeities

8. Aorta 5 sections of the Ao. Largest artery in the body
Root: Originates from the Left Ventricle of the heart
Ascending Ao. – ascends a short distance from the vent and arches superiorly

9. Aorta
Arch- passes to the left in front of the trachea bends dorsally and becomes the descending Ao.
Three major branches
Innominate (Brachiocephalic)
Left Common Carotid
Left Subclavian
Descending- from the Ao arch it courses posteriorly through the thoracic cavity
Pierces the diaphragm at the thoracic cavity

10. Arch anatomy

12. Abdominal Aorta
Retroperitoneal structure enters the abd. at the Ao hiatus of the diaphragm (T-12 and ends at L-4 vertebrae)
Courses anterior to the vertebral bodies and slightly left of the midline
Moves from a posterior and superior position to an anterior and inferior position
Its diameter decreases the more inferior it descends (2-3 cm superiorly at diaphragm and 1-1.5cm inferiorly)
Bifurcates at the level of L-4 into the right and left common iliac arteries

14. Abdominal Aorta Anterior or Ventral Branches Lateral Branches
Celiac
SMA- Superior Mesenteric Artery
IMA- Inferior Mesenteric Artery
Lateral Branches
Phrenic artery
Right and Left Renal Arteries
Gonadal arteries
Dorsal Branches
Lumbar
Terminal
Aorta bifurcates at the level of L-4 into the right and left common iliac arteries

15. Splanchnic Arteries
Refers to the vessels that supply blood to the bowel
Principally, the celiac axis, superior mesenteric artery (SMA) and the inferior mesenteric artery (IMA)
Stenosis or occlusion can cause acute or chronic bowel ischemia; however, collaterals usually prevent ischemic bowel

17. Celiac Axis
In the transverse scan plane its branches forms a seagull or a dove configuration
Left Gastric Artery
Common Hepatic Artery
Splenic Artery

18. Celiac Axis Left Gastric Artery
Smallest branch of the CA – not typically seen with ultrasound
Travels upward and to the left of the stomach
Supplies the lesser curvature of the stomach
Can serve as a collateral pathway in the event of a severe stenosis or occlusion

19. Celiac Axis Common Hepatic Artery
Courses to the right of the abd. At almost a 90 degree angle along the superior border of the pancreatic head
Passes anterior to the portal vein
Lies to the left of the common bile duct
Gives rise to the GDA origin, the common hepatic artery becomes the proper hepatic artery which follows the portal vein to the portal hepatis (hilum of the liver)
At the portal hepatis, the proper hepatic artery bifurcates into the right and left hepatic arteries

20. Hepatic Artery

21. GDA Gastroduodenal artery Arises from the common hepatic A
Runs parallel to the CBD at its origin and with it, defines the later border of the pancreatic head
Anterolateral to the head of panc.
CBD- is posterolateral to the head of panc.

22. Celiac Axis
Splenic Artery (difficult to image due to its tortuous nature)
Largest Branch
Follows a tortuous course along the superior margin of the panc. body and tail
Gives rise to: (not readily seen on U/S)
Several pancreatic branches
Left gastroepiploic a.
Gastric branches
Terminates at the splenic hilum
Flow is turbulent

23. A

25. SMA
Celiac
Aorta

26. Proximal Celiac Artery (Doppler angle 60 degrees or less)

27. Superior Mesenteric Artery (SMA)
Anterior branch of the Abdominal Ao.
Approximately 1cm below the celiac axis at a 10 degree angle
Consists of a short segment that courses anteriorly from the Ao. then runs inferiorly parallel to the Ao. ending in the vicinity of the ileocecal valve
Runs anterior to the Left Renal Vein
Posterior to the pancreatic body
Anterior to the uncinate process of the pancreas and the 3rd portion of the duodenum

28. SMA
Surrounded by a triangular shaped area of retroperitoneal fat- appears echogenic on ultrasound
Lies to the Left of the SMV
Branches Supply:
Jejunum, ileum cecum, ascending colon,
Prox. 2/3rd of the transverse colon, portion of the pancreas and duodenum

29. SMA Best evaluated in the longitudinal plane
Turbulent flow at the origin
Laminar flow as the vessel straightens out
Pre-prandial: high resistance
Post-prandial: low resistance

31. GDA
Splenic Vein
Left Renal Vein
SMA
IVC
Aorta

32. SMA (Doppler angle 60 degrees or less)

33. SMA Pre-prandial Supplies a changing vascular bed
Preprandial signals exhibit:
Highly pulsatile signals
Are triphasic
And have somewhat of a reversal component below baseline

34. SMA (post prandial) Changes dramatically post prandial
Becomes hyperemic
Should remain above baseline
Exhibit antegrade flow throughout the cardiac cycle

35. Inferior Mesenteric Artery (IMA)
Arises from the Ao. anteriorly, 3-4 cm above the bifurcation
Courses inferiorly and slightly left
Often obscured by bowel gas; when visualized- best viewed in the longitudinal plane
Acts as a collateral pathway in the event of SMA, CA occlusion. If the IMA is easily seen on U/S; evaluate the SMA and CA for stenosis or occlusion.

36. IMA
In the event of an acute SMA occlusion, the IMA will not have enough time to become a collateral and will not be prominent on U/S
Supplies blood to:
Left third of the transverse colon
Sigmoid colon
Rectum

37. Renal Arteries
Lateral branch of the Ao. that arise at or 1-2cm below the origin of the SMA
Supplies blood:
Kidneys
Adrenal glands
Perirenal fat and body wall
Best visualized in the transverse scan plane

38. Banana Peel

39. Renal Arteries Run posterior to the renal veins
RRA arises from the anteriolateral aspect of the Ao. slightly inferior to the
LRA
RRA is longer than LRA due to its Aortic position
RRA is posterior to the IVC, RRV, Pancreatic Head, Descending duodenum before entering the right kidney at the hilum

40. Right Renal Artery passes posterior to the IVC
Rt Renal Artery
Rt Renal Artery

42. Segmental, Interlobar, Arcuate Arteries

43. Parenchymal Flow
Interlobar (medulla)
Arcuate (cortex)

44. Main Renal Artery Branches into Segmental, Interlobar, Arcuate, and Interlobular

45. Renal Arteries
LRA lies posterior to the LRV, body of the pancreas and the splenic vein
Common pitfall: confusing crura of the diaphragm with the RA’s
10–20% of the patient’s have multiple renal arteries which often arise superior or inferior to the main arteries (accessory arteries)
May attach to the kidneys at the poles
May arise from the iliac arteries

46. Gonadal Arteries
Arises anteriolaterally from the aorta just inferior to the renal arteries
Small and difficult to visualize on U/S
Course along the psoas muscle to the respective gonadal area
Testicular arteries course through inguinal canal and are part of the spermatic cords leading to the testicles; supply the testicles
Ovarian arteries enter the pelvic cavity and supply the ovaries

47. Inferior Vena Cava (IVC)
Retroperitoneal, valveless vein that courses superiorly to the right of the midline; formed by the common iliac veins at L-5
Carries deoxygenated from all parts of the body below the diaphragm to the right atrium of the heart
Courses horizontal until it angles anteriorly into the right atrium

48. IVC
The IVC is posterior to the main portal vein, caudate lobe and head of the panc.
The RRA is posterior to the IVC
IVC changes with respiration and valsalva maneuver
Inspiration – increases in size
Expiration – decreases in size
Valsalva – increases in size

49. IVC Normal

50. IVC Upper limits of its normal diameter is 3.7cm Tributaries include:
Hepatic veins
Right adrenal veins
Renal veins
Gonadal veins
Inferior phrenic vein
4 lumbar veins
Common Iliac Veins (L-5)
Median sacral vein

51. Renal Veins Course anterior to the RA’s
Only veins that run anterior to the artery
Course into the IVC at right angles
Best seen in transverse
Left Renal Vein
Longer than the RRV
Passes posterior to SMA, SA, panc. body
Passes anterior to the Ao
Drains into the anteriomedial aspect of the IVC

52. Renal Veins course Anterior to the Renal Arteries
Left Renal Veins courses posterior to the SMA and anterior to the Aorta
Aorta
Renal Veins course Anterior to the Renal Arteries

53. Renal Veins Right Renal Vein Passes anterior to the RRA
Drains into the posterolateral aspect of IVC
Can be mistaken by the right crus of the diaphragm

54. Gonadal Veins Testicular veins Ovarian Veins
Enters the pelvis through the inguinal canal
Courses along side the testicular arteries
Right drains into the IVC just below the RRV
Left drains into the LRV
Ovarian Veins
Emerge from the ovaries
Drains same as the testicular veins

55. Portal Venous System
Transports blood from the spleen and bowel to the liver
Is formed by the confluence of the splenic v. and the SMV at the head of the pancreas
Portal veins course within the lobes and segments of the liver
Portal veins have echogenic walls
Provides 70-80% of the blood supply to the liver

56. Splenic Vein Large tortuous vein that lies posterior to the pancreas
Arises from the hilum of the spleen
Drains the spleen, pancreas and stomach
Best seen in transverse scan plane
Joins the SMV to form the Main Portal Vein

57. Superior Mesenteric Vein
Originates at the route of the mesentery in the Right Iliac fossa
Drains the pancreas, transverse colon and ascending colon
It is anterior to the IVC, third part of the duodenum and the uncinate process of the pancreas
Posterior to the neck of the pancreas
Courses superiorly to the right of the SMA

58. Main Portal Vein Formed by the confluence of the SV and SMV
Confluence is posterior to the pancreatic neck runs through the lesser omentum to the porta hepatis where it divides into the right and left portal vein
With the CBD and HA, it forms the Portal Triad; the CBD is anterior and to the right of the MPV the HA is anterior and to the left of MPV. (mickey mouse sign)
Measures 11mm +/- 2mm in AP diameter
Should not exceed 13mm
Branches into the right and left portal veins

59. Portal Triad: Mickey Mouse Sign
Porta Hepatis:
Underside of liver
Point at which the
portal vein and
hepatic artery enter
the liver
Exit site for
the hepatic duct and lymphatic system
* When using color imaging, the CBD will not fill in with color
Hepatic A
CBD
Portal V

60. Portal Vein (Normal)

61. Right Portal Vein
Shorter, larger in diameter and more inferior than the LPV
Bifurcates into the anterior and posterior segments in the right lobe of the liver
Receives the cystic vein from the gallbladder and gives a branch to the caudate lobe of the liver

62. Right Portal Vein

63. Left Portal Vein
Longer and smaller in diameter, more anterior and superior than the RPV
Courses anterior to the caudate lobe on its way to the left lobe
Gives branches to the caudate lobe before entering the left lobe
Bifurcates into lateral and medial segments in the left lobe of the liver

64. Hepatic Veins Three hepatic Veins Right Hepatic Vein –
Runs in the right intersegmental fissure of the liver
Divides the right lobe of the liver into posterior and anterior segments
Drains the right lobe of the liver
Middle Hepatic Vein-
Drains the caudate lobe of the liver
Runs in the main lobar fissure
Divides the liver into the right and left lobes

65. Hepatic Veins Left Hepatic Vein Drains the left lobe of the liver
Runs in the left intersegmental fissure of the liver
In 96%of individuals, the middle and left hepatic veins join to form a COMMON TRUNK before entering the IVC
Divides the left lobe into lateral and medial segments

67. Hepatic veins entering the IVC

68. Hepatic Veins

69. Differentiate between Portal and Hepatic Veins on ultrasound
Course
Hepatic veins runs longitudinally
Portal veins run transverse
Convergence
Hepatic veins converge on the IVC at the diaphragm
Portal veins converge at the portal hepatis
Size
Hepatic V. enlarge towards the IVC
Portal V. enlarge towards the porta hepatis

70. Differentiate between Portal and Hepatic Veins on ultrasound
Margins
Hepatic V. do not have margins
Portal V. surrounded by a bright sheath of fibrous tissue
Doppler Characteristics
Hepatic V. flow is pulsatile and chaotic due to the close proximity to the heart
Portal V. more phasic and organized

71. Portal Venous Flow

72. Portal Vein CHF (Abnormal)

73. Normal HV Doppler

74. Hepatic Veins Cardiac Failure