Venous.3.Venous thrombosis Flashcards
Types of Venous thrombosis
- Superficial venous thrombosis.
2. Deep venous thrombosis :
sites of Deep venous thrombosis.
- Occurring mainly in the calf or iliofemoral veins.
* Less common sites are the inferior vena cava, subclavian, axillary or portal veins.
Etiology of Superficial venous thrombosis.
- Varicose veins.
- Veins cannulated for I.V. infusion.
- After injection of irritant drugs, e.g. diazepam.
- Migrating thrombophlebitis in association with :
a. Buerger’s disease.
b. Visceral malignancy (it may be the earliest sign of malignancy) :Trousseau’s sign.
c. Polycythaemia. - Idiopathic.
Migrating thrombophlebitis occurs in
a. Buerger’s disease.
b. Visceral malignancy (it may be the earliest sign of malignancy) :Trousseau’s sign.
c. Polycythaemia.
Trousseau’s sign
Migrating thrombophlebitis in Visceral malignancy (it may be the earliest sign of malignancy)
Clinical picture of Superficial venous thrombosis.
l. The vein becomes red, painful and cord like.
2. There may be slight pyrexia.
Complication of Superficial venous thrombosis.
l. If infection sets in, rapid upward spread occurs with the danger of extension to the deep veins via the communicating veins
2. The thrombus is adherent to the vein wall as there is inflammation Pulmonary embolism never occurs.
Treatment of majority of cases of Superficial venous thrombosis.
l. Compression by elastic stocking.
2. Anti-inflammatory drugs. e.g. aspirin.
These are usually enough for treatment of the majority of cases.
Superficial venous thrombosis Treatment resorted to under special circumstances
- Antibiotics only if there is evidence of infection.
- Anticoagulant therapy ( heparin and warfarin ) is given in severe progressive cases (ascending thrombo-phlebitis ).
- Surgerv : Prophylactic sapheno-femoral or sapheno-popliteal disconnection is done if the process of thrombosis is found ascending up towards the junction with the deep system
Etiology of DVT
Virchow’s Triad:
- Damage to the endothelial lining of the vein wall
- Venous stasis
3- Hypercoagulability of blood
in Virchow’s Triad, Damage to the endothelial lining of the vein wall is due to:
- Trauma to the vein wall, €.g. during pelvic operations.
* Inflammatory process near the vein, e.g., pelvic sepsis.
in Virchow’s Triad, Venous stasis is due to:
- Prolonged bed confinement, long trips, or casts.
- Congestive heart failure.
- Venous compression by tumours, a pregnant uterus or pillows under the knees.
in Virchow’s Triad, Hypercoagulability of blood is due to:
- Deficiency of antithrombin III, proteins S or C.
- Polycthaemia.
’ * Postoperative dehydration
proteins S or C.
natural anticoagulant inactivates factor 5 and 8
PREDISPOSING FACTORS of DVT
- All the factors mentioned before under Virchow’s triad.
- Added to those are
- Obesity.
- Oral contraceptives intake.
- Previous DVT.
- Old age.
- Malignancy.
- Major trauma-
- Major surgery.
PATHOGENESIS of DVT:
- The process usually starts in the calf venous sinuses or in iliac and femoral veins by adherence of platelets to the endothelial surface forming a grey cluster
- Then more platelets adhere. Fibrin and RBCs are deposited as layers in-between the platelets giving a laminated appearance Known as the lines of Zahn.
- When the vein is totally occluded propagated thrombus spreads up the vessel as far as the next major tributary.
- At this stage the thrombus is loosely attached and it can be easily detached leading to P.E.
- Later(After 7 -10 days), the thrombus becomes tightly adherent to the vein wall by fibrin deposition.
- It then organizes and contracts thus producing destruction of the valves and luminal narrowing, which are responsible for the eventual development of the post- phlebitic limb syndrome .
- Later on the processes of fibrinolysis and phagocytosis start & help in recanalization of the vein but the valves are permanently destroyed.
the reason why When the vein is totally occluded propagated thrombus spreads
up the vessel as far as the next major tributary
As the stasis factor is lost
the reason why DVT is more common on the Lt. side
because of the anatomical fact that the Rt. common iliac artery crosses over and compresses the Lt. common iliac vein
Clinical picture of DVT
A. Silent & asymptomatic
B- The classical picture.
C. Critical types of iliofemoral DVT
Silent & asymptomatic Clinical picture of DVT
- Silent DVT is a frequent occurrence.
- There are no local symptoms and the patient may present with either P.E or later with the manifestations of CVI.
- However, it may be suspected by the presence of unexplained rise of temperature or pulse rate
Silent & asymptomatic Clinical picture of DVT may be suspected by
the presence of unexplained rise of temperature or pulse rate
The classical picture of DVT
Triad of :
- Pain
- Swelling
- Tenderness
Pain in The classical picture of DVT
Aching, bursting pain & tightness in the involved calf or thigh, which are aggravated by muscular exercise.
Swelling in The classical picture of DVT
- This is the most reliable physical sign.
- It is evidenced by Measuring the difference in the circumference between both sides.
- In calf thrombosis the swelling is limited to the foot and ankle.
- In femoral thrombosis the swelling involves the calf and lower part of the thigh.
- While in ilio-femoral thrombosis there is massive swelling affecting the whole lower limb.
site of swelling in calf thrombosis
the foot and ankle
site of swelling in femoral thrombosis
the calf and lower part of the thigh
site of swelling ilio-femoral thrombosis
massive swelling affecting the whole lower limb.
in calf thrombosis the affected vein is
Popliteal or soleal venous plexus
Tenderness in the classical picture of DVT
Is present on grasping the affected calf or thigh.
Homan’s sign
Calf pain on dorsiflexion of the foot.
It is not reliable & may cause showers of P.E on application
Critical types of iliofemoral DVT
- Phlegmasia alba dolens :
2. Phlegmasia cerulea dolens :
Meaning of Phlegmasia alba dolens
Phlegmasia: leg
alba: white
dolens: pale
Meaning of Phlegmasia cerulea dolens
Phlegmasia: leg
Cerulae: blue
dolens: pale
Pathogenesis of Phlegmasia alba dolens
Massive iliofemoral DVT associated with severe arterial spasm or lymphangitis & so the limb becomes pale, white, and massively swollen with absent peripheral pulses, and may end in venous gangrene
Pathogenesis of Phlegmasia cerulea dolens
Very Massive iliofemoral DVT may be associated with severe congestion
and cyanosis and the whole lower limb looks massively swollen and blue and if not properly treated it may lead to venous gangrene.