Extremity Venous Anatomy and Sonographic Evaluation

• Thin walled, collapsible
• Still allows for some dilatation and constriction
• Media layer thinner than artery
• Walls of the upper extremity veins contain much less muscle than walls of the veins in the lower extremity and especially the feet; this is due to hydrostatic pressure
• Progressive increase in size as they get closer to heart
• Most contain valves
• Veins originate distally as venules in the extremity(hands/feet) and travel to right atrium
• Capillary beds are composed of intima only and connect to venules
• Venules are composed of intima and adventitia layers only (no media layer)
• Pressure in the venules normally does not exceed 20mmHg
• 80% of the blood in the body is found in the venous system
• Concomitant veins - refers to a vein that is usually paired, with a vein lying on either side of a single artery
  • Radial, ulnar, PTV, ATV, peroneal and gastrocnemius veins are example of concomitant veins

Central Veins:

•  Inferior Vena Cava IVC - confluence of iliac veins
•  Hepatic veins
•  Superior Vena Cava SVC - confluence of innominate veins
•  Portal vein-confluence of SMV and splenic vein

Lower Extremity Deep Veins:

Deep digital veins > metatarsal veins > Deep venous arches > PTVs and peroneal veins > tibioperoneal trunk > ATVs > popliteal vein > superficial femoral vein > common femoral vein > external iliac vein

• Veins in the lower extremity originate at the confluence of the venules of the deep digital veins
• Metatarsal veins drain the blood from the foot and merge into the deep venous arches
• Deep venous arches empty their blood into tibial veins
• Calf and forearm veins are referred to as venae comitantes because 2 veins of the same name follow the same course as a single artery of the same name

Anterior Tibial Veins:

• Drain blood from the anterior calf
• 2 veins originate at the plantar arches
• Course cephalad anterolateral to the tibial bone and the interosseous membrane to reach the tibioperoneal trunk
• Travels between the tibial head and fibula head to join the popliteal vein
• Best scan approach is anterior calf with slightly lateral probe position

Posterior Tibial Veins:

• Drain blood from the posterior calf
• 2 veins originate at the confluence of the plantar arches
• At the ankle the PTVs course posterior to the medial malleolus and anterior to the Achilles' tendon then course cephalad through the calf posterior to the tibial bone
• Best scan approach is to place probe on the medial calf, angling through to the lateral side; PTVs most anterior on image and peroneals visible beneath them

Peroneal Veins:

• Drain blood from the lateral calf
• In the lower calf/ankle 2 veins course lateral to the PTVs and medial to the fibula,
• Continue in a cephalad course up the midline of the posterior calf, posterior to the fibula
• 2 peroneal veins and 2 posterior tibial veins merge to form a single tibio-peroneal trunk in the upper calf
• Best scan approach is to place probe on the medial calf, angling through to the lateral side; PTVs most anterior on image and peroneals visible beneath them

Popliteal Vein:

• Tibioperoneal trunk merges with the two anterior tibial veins to form the popliteal vein in the popliteal fossa
• Courses posterior to the popliteal artery
• Becomes the femoral vein at adductor hiatus in the distal thigh
• Best scan approach is to place probe on the posterior popliteal fossa; popliteal vein demonstrated ANTERIOR to the popliteal artery on the image due to the scan approach

Femoral Vein:

• AKA superficial femoral vein (SFV); nomenclature recommendations remove the term superficial to alleviate confusion regarding this deep vein
• Extends from adductor hiatus to join the profunda femoral vein at the groin
• Courses posterior to the femoral artery

Profunda Femoral Vein:

• AKA deep femoral vein (DFV); nomenclature recommendations remove the terms superficial and deep to alleviate confusion regarding both of these veins being part of the deep venous system
• Joins the femoral vein to form the common femoral vein just below inguinal ligament
• Drains the muscles in the thigh (quadriceps)

Common Femoral Vein:

• Formed by the junction of the FV and PFV, just below the inguinal ligament
• Courses beneath the inguinal ligament
• Becomes external iliac vein just above inguinal ligament at the groin crease
• Courses medial and posterior to common femoral artery

Internal Iliac Vein:

• Courses medial to the external iliac vein
• Drains the pelvic organs (NOT the gonads)

External Iliac Vein:

• Courses lateral to the internal iliac vein and anterior to the external iliac artery
• Joins the internal iliac vein to form the common iliac vein

Common Iliac Vein:

• Courses anterior to the common iliac artery
• Right and left common iliac veins merge at the level of L5 to form the IVC
• IVC empties into the right atrium

Klippel - Trenaunay - Weber Syndrome:

• Congenital absence of the deep veins
• Causes numerous superficial varicosities and clusters of varicosities