Popliteal artery

• ○
  

  Begins as continuation of superficial femoral artery after it has passed through adductor hiatus (inferior end of adductor canal)

  
  
• ○
  

  Runs through fat of popliteal fossa

  
  
• ○
  

  Relationships

  
  
  
  
  • –
    

    Deep to artery: Femoral shaft, knee joint capsule, popliteus fascia

    
    
  • –
    

    Superficial to artery: Popliteal vein, semimembranosus muscle, and gastrocnemius muscle

  
  
  
  
• ○
  

  Artery lies just deep to vein in 40%, deep and medial to vein in 43%, deep and lateral to vein in 9%, and just medial or lateral to vein in 8%

  
  
• ○
  

  Ends at distal border of popliteus muscle dividing into 2 branches: Anterior tibial artery and tibioperoneal trunk

Anterior tibial artery

• ○
  

  Smaller of the 2 terminal branches of popliteal artery

  
  
• ○
  

  Origin in back of leg, at distal border of popliteus muscle

  
  
• ○
  

  Passes through upper part of interosseous membrane

  
  
• ○
  

  Straight course down front of leg to become dorsalis pedis artery

  
  
• ○
  

  Runs on anterior surface of interosseous membrane, deep to extensor muscles

  
  
• ○
  

  Muscular branches along length

  
  
• ○
  

  Malleolar branches ramify over malleoli; lateral branch anastomoses with perforating branch of peroneal artery

Posterior tibial artery

• ○
  

  Larger of 2 terminal branches of popliteal artery

  
  
• ○
  

  Main blood supply to foot

  
  
• ○
  

  Passes downward and slightly medially along with tibial nerve to end in space between medial malleolus and calcaneus

  
  
• ○
  

  Within calf, artery runs just deep to transverse intermuscular septum

  
  
• ○
  

  Divides into lateral and medial plantar arteries in tarsal tunnel behind medial malleolus

  
  
• ○
  

  Branches

  
  
  
  
  • –
    

    Circumflex fibular (may arise from anterior tibial), runs laterally around neck of fibula

    
    
  • –
    

    Nutrient artery to tibia

    
    
  • –
    

    Muscular branches

  
  

Peroneal artery

• ○
  

  Largest branch of posterior tibial artery

  
  
• ○
  

  Runs obliquely downward and laterally beneath soleus to fibula

  
  
• ○
  

  Descends deep to flexor hallucis longus

Popliteal vein

• ○
  

  Paired venae comitantes of anterior and posterior tibial arteries join to form popliteal vein

  
  
• ○
  

  Also receives small saphenous vein in popliteal fossa

  
  
• ○
  

  Usually begins at inferior border of popliteus muscle

  
  
• ○
  

  Crosses from medial to lateral side of popliteal artery as it runs in popliteal fossa, aside from always being superficial to popliteal artery

  
  
• ○
  

  Ends at adductor hiatus by becoming superficial femoral vein

Great saphenous vein

• ○
  

  Begins at medial border of foot

  
  
• ○
  

  Ascends in front of medial malleolus

  
  
• ○
  

  Passes obliquely upward and backward across medial surface of distal 1/3 of tibia

  
  
• ○
  

  Passes vertically upward along medial border of tibia to posterior part of medial side of knee

Small saphenous vein

• ○
  

  Extends behind lateral malleolus, ascends lateral to Achilles tendon

  
  
• ○
  

  At midline of calf in lower popliteal region, pierces popliteal fascia, and terminates in popliteal vein

Ultrasound

• ○
  

  Examination of lower limb vessels requires use of morphological and functional techniques

  
  
  
  
  • –
    

    Morphology: Documentation of areas of stenosis or occlusion, sites of venous valves, aberrant branches, aneurysm formation, etc.

    
    
  • –
    

    Functional: Combination of color and spectral Doppler examination

  
  
  
  
• ○
  

  Veins require use of dynamic maneuvers

  
  
  
  
  • –
    

    Compression: To demonstrate absence of thrombus by using transducer pressure to cause complete luminal occlusion

    
    
  • –
    

    Valsalva: To increase abdominal pressure and accentuate reverse flow and incompetent venous valves

    
    
  • –
    

    Augmentation: To increase venous return (to demonstrate venous flow and patency) by manually squeezing calf or by gently moving toes

  
  
  
  
• ○
  

  Arteries require use of spectral Doppler scanning to show their phasicity; normal scan is triphasic

  
  
  
  
  • –
    

    Sharp forward flow upstroke (systolic phase)

    
    
  • –
    

    Small reversed flow (early diastolic phase)

    
    
  • –
    

    Final smaller forward flow (late diastolic phase)

  
  

Augmentation frequently required to demonstrate flow in deep calf veins (which normally show no color Doppler flow)