Venous LE Flashcards
Veins: thin walled collapsible tubes, expand. 3 layers. Media layer is thinner than artery media.
Valves in intima
Media
Adventitia. Contains vasa vasorum.
Transport blood to heart, regulate body temp, and cardiac output. Storage reservoir for blood
Deep
Superficial
Perforating
SVC
Confluence of innominate veins. Drain head and upper extremities.
IVC
Confluence of iliac veins. Drain lower body.
Deep veins
Accompanied by an artery
Surrounded by muscle
Bring blood back to heart
Thrombus have higher risk for PE
Deep femoral vein used to be
Profunda
Femoral vein becomes popliteal vein after passing ______
Adductor’s canal aka hunters canal
First deep vein to come off pop V
2 Anterior tibial vein
Gastruc nemeus vein
Also comes off pop vein. Stay in gastruc nemus muscle. 2 veins 1 artery.
Tibioperoneal trunk
Bifurcates into PTV and Peroneal Veins. Paired.
Solleal sinus veins
Enter into either ptv or Peroneal veins. Storage veins. Clots form when calf muscle not active.
Venous sinuses
Gastrocnemius vein (drains into pop vein) and soleal vein (drains into PTV and Pero V)
Superficial veins
No artery. Regulate body temp. Hot, enlarge to move blood close to skin to let heat escape body.
GSV (large saphenous)
Empties into CFV below inguinal ligament.
Small saphenous vein
Used to be called Lesser saphenous vein. Empties into Pop V around same level as gastruc nemius.
Some people it empties into femoral vein.
Between Fascia
Longest vein in the body
GSV
Vein often used in coronary artery bypass graft.
GSV
Gaicomini vein
Variant of lesser/short saphenous
Not present in everyone.
Connects LSV to GSV
Perforators
Connect veins deep to superficial
If not working, blood pools and ulcers occur.
80-140 perforators in lower extremities.
*posterior accessory GSV (aka posterior arch vein): superficial connection of 3 ankle perforating veins. Posterior tibial perforators, upper mid and lower.
Communicating veins
Connect veins in same system. Deep to deep. Superficial to superficial.
Perforator of femoral canal (Hunter’s) and (Dodd’s perforator)
Perforator of Femoral Canal
Paratibial perforator (Boyd’s)
Perforator at knee
Tibial perforator upper (Cockett III) middle (Cockett II) and lower (Cockett I).
Perforator in calf
Venous valves
Bicuspid. Allow blood to flow in one direction.
Stats
> 2.5 million cases of venous thromboembolic disease in US
25% of untreated DVT will sustain a nonfatal pulmonary embolism.
Untreated PE assoc with 30% mortality rate.
Venous hemodynamics
Low pressure Pressure/volume Cardiac influence Respiration Posture (hydrostatic pressure) Calf pump
Venous pressure / volume relationship
Resistance: flat shape of vein offers more flow resistance than circular shape
Shape of vein is determined by transmural pressure ( pressure difference from inter mural in vein and interstitial pressure outside of vein )
Small pressure changes required to expand or distend vein from normal dumbbell shape to a circular one.
Extra pulmonary venous circulation carry about 2/3 of the blood in the body. Veins carry more blood than arteries, without the increase in pressure.
Reverse transdelenburg fills up calf veins.
Cardiac influence
Venous pressure and flow are affected by cardiac activity
This effect is most pronounced in thoracic vessels due to atrial contraction and relaxation. Jugular and subclavian can be very pulsatile. Due to proximity of heart.
Usually not apparent or reduced in lower extremities.
Pulsatile flow in LE indicates
Congestive heart failure. Or right heart failure.
Due to high pressure in the right side of heart. Occurs bilaterally.
Respiration variation.
Venous flow highly dependent on respiration.
Inspiration: Diaphragm moves downward and increases infra abdominal pressure.
IVC is compressed and venous outflow is temporarily reduced or stopped.
Exhalation: blood flow resumes.
Respiratory phasicity is opposite in arms.
Valsalva
Inhale and bear down.
Blood flow should stop in LE
Opposite for UE
Hydrostatic pressure
Weight of Column of blood extending from heart to level where pressure is being measured.
Fórmula HP= pgh
Inc transmural venous pressure distally
Venous distension: due to transmural pressure
Venous pooling :due to hydrostatic pressure, blood unable to go back up leg
Dec in capillary perfusion
Dec in venous return
Dec in cardiac output.
If stand in one place for too long without moving you can pass out. Hypotension
Hydrostatic pressure =
gravity of blood * acceleration due to gravity * distance from heart.
HP = pgh
Heart reference 0 mmHg
Standing = 100 mmHg. Higher the further you go. At feet. Due to venous pooling.
HP decreases if knee is raised above level of heart.
22mmHg per every inch tall a person is.
Lying 10mmHg
Walking 25mmHg
Calf veno-motor pump
Muscles in calf contain deep veins. Aug calf and not thigh.
Veins: PTV, pero, atv, gastric nemus, soleol sinus, GSV, LSV and perforator.
Valves. Need to pump blood out against Hydrostatic pressure.
Muscles
During muscle contraction, blood is propelled upward. Proximal valve opens while distal valve is closed. Perforator valves close during muscle contraction. To prevent flow in superficial system. (Perforators connect superficial to deep veins)
Valve closes, muscle relaxes.
Calf pump returns blood to heart, reduces hydrostatic pressure and venous pooling. And is depending on competent valves and muscle contraction.
Virchow’s Triad
Risk factors for vein thrombosis
3 categories:
•endothelial damage (vessel trauma): IV drugs, catheter, extrinsic trauma, long trips
- venous stasis: bed rest, paralysis, HTN, pregnancy, IVC compression, SVC syndrome, obesity
- hypercoagulability: pregnancy, hormone, cancer, inherited states. Leiden favor 5
Airplanes.
DVT
Common
80% of PE come from dvt
F>M
LE DVG commonly originate in calf veins at valve leaflets. Soleal sinus MC site.
Well score
Points to determine risk for DVt
0= low probability
1-2=intermediate
> or = 3 = high probability
D dimer: measures five in degration products that accumulate in blood when thrombus form.
Neg: DVT is unlikely
Pos: false positive or further testing to check for DVT
Criteria for vein thrombosis
Absence of vein compressibility (most important)
Visualization of thrombus
Vein distention
Abnormal Doppler signals
Reduced/absent augmentation
Reduced/absent color filling.
Positive homan’s sign
Person flex foot and gets calf pain.
Venous vs arterial symptoms
Venous: acute, swelling, persistent pain in calf or thigh, local tenderness, palpable cord with superficial thrombus, chest pain or short of breath with PE, warm to touch, redness.
Arterial: progressive, claudication, rubor dependent, limb/foot coolness, limb pallor, gangrene.
Acute vs chronic DVT
Acute: hypoechoic, poorly attached (can cause PE), spongy texture, dilated vein (complete obstruction)
Chronic: echogenic, well attached, rigid texture, contracted vein (complete obstruction), collaterals, thickened vein wall.
20% of chronic DVT. Recanulization occurs and can see flow again.
Phlegmasia Alba Dolens “Milk Leg”
Limb threatening
Arterial spasms occur secondary to extensive acute iliofemoral vein thrombosis. Arterial spasm causes insufficient arterial blood flow.
Limb is swollen, pale, and painful White leg because of arterial insufficiency.
Phlegmasia Cerulia Dolens
Limb threatening
Acute iliofemoral vein thrombosis with severely reduced venous outflow which causes a marked reduction in arterial inflow.
Tissue hypoxia
Venous gangrene
Limb is swollen, darker, bluish / cyanosis, and painful. Due to insufficient oxygen.
May Thurber syndrome
Left common iliac vein is compressed by the right common iliac artery.
Continuous flow in femoral vein would indicate a proximal obstruction. Will be hard to compress.
Normally the LCIV passed under the RCIA to empty into IVC.
Venous flow patterns
Phasic: flow should stop when inhaling and resume with exhale.
Augmentation: should produce inc flow pattern with maneuver
Prox compression: venous flow should stop. Should mimic valsalva maneuver.
Loss of respiratory phasicity indicates (continuous flow)
Inability to augment
Proximal obstruction
Continuous flow in femoral vein could indicate
Proximal dvt in the iliac
Pulsatile venous flow represents
Congestive heart failure or right heart failure.
Represents fluid overload:
Over hydration and chronic venous insufficiency can also be causes.
(Pulsatile flow is normal in subclavian due to proximity to heart)
Superficial thrombophlebitis
Erythema/inflammation
Local tenderness
Palpable cord or mass
Usually more painful than DVT
Varicosites
Varicose veins swirl. And GSV does not.
Venous insufficiency/ venous reflux
- Primary: congenital absence or defect of valves
- Secondary: valves damaged by venous thrombosis and or chronic outflow obstruction. Postphlebotic syndrome
Symptoms: recurrent swelling/edema, leg pain, varicose veins, heaviness, stasis dermatitis (brawny edema) at ankle, ulceration (gaiter zone)
Venous vs arterial ulcers
Venous: near medial and lateral malleolus (gaiter zone). Mild pain, shallow irregular shape, oozy, stasis dermatitis and brawny discoloration.
Arterial: lower leg or feet, severe pain, deep, regular shape, small size, trophic changes: hair loss, shiny skin, thickened toenails.
Valsalva
Have patient take a breath in and bear down. Should stop venous flow if valves are working. Coughing should elicit same response.
Can also stop venous flow with proximal compression.
Reversal slow seen in venous insufficiency.
Bakers cyst aka Synovial cyst
Synovial lining and fluid bulge into the pop space
Found in medial aspect of pop fossa
May dissect into medial calf muscles
Soft tissue edema
Limb swelling associated with elevated venous pressure (hydrostatic pressure)
•CHF
•venous compression
•fluid overload.
Typically bilateral
Changes in venous flow pattern: pulsatile or bidirectional.
Lymphedema
“Ant farm” appearance
Blockage in lymphatic system that prevents lymph fluid from draining well
Caused by malignancy, trauma, injury,
Mimics dvt. Excess lymph fluid Leg swelling Pain Unilateral or bilateral.
Cellulitis
Infection/inflammation of tissue in calf
Redness, shiny, warm to touch, not related to DVT.
