Venous Drainage of Lower Limbs

Dr  Meera Narendran BHMS,MD(Hom)
The lower limbs has superficial and deep veins; the superficial veins are in subcutaneous tissue, and the deep veins are in to the deep fasica and accompany all major arteries. The veins of lowerlimb act as a complex pumping meachanism capable of returning venous blood to the heart against the force of gravity in the upright position.

Superficial veins of the lower limb
The two major superficial veins in the lower limb are the great and small saphenous veins.

The great saphenous veins is formed by the union of the dorsal vein of the great toe and the dorsal venus arch of the foot. The great saphenous vein.

• Ascends anterior to the medical malleolus.
• Passes posterior to the medical condyl of the femur.
• Anastamoses freely with the small saphenous vein.
• Transverses the saphenous opening in the fascia lata.
• Empties in to the femoral vein.
• The great saphenous vein has 10 to 12 valves. These valves are usually located just inferior to the perforating veins. The perforating veins also have valves. This valvular mechanism enables the blood in the saphenous vein to overcome the force gravity as it passes to the heart.
• As it ascends in the leg and thigh, the great saphenous vein recieves numerous tributaries and communicates in several locations with the small saphenous vein. Tributaries from the medical and posterior aspects of the thigh frequently unite to from an accessory saphenous vein.
• The lateral and anterior cutaneous vein arises from networks of veins in the inferior part of the thigh and enter the great saphenous vein superiorly, just before it enters the femoral vein. Near its termination the great saphanous vein also receives the superficial circumflex iliac, superficial epigastric, and external pudendal veins.
• The small saphenous vein arises on the lateral side of the foot from the union of the dorsal vein of the small toe with the dorsal venous arch.

The small Saphenous vein.

• Ascends posterior to the lateral malleolus as a continuation of the lateral marginal vein.
• Passes along the lateral border of the calcaneal tendon.
• Inclines to the midline of the fibula and penetrates the deep fascia.
• Ascends between the heads of the gastronemus muscle.
• Empties into the politeal vein in the popliteal fossa.

Although many tributaries are received by the saphenous veins, their diameter remains remarkably uniform as they descend the limb. This is possible because the blood they received is continuously shunted from these superficial veins in the subcutaneous tissue to the deep veins by means of the many perforating veins.
The perforating veins, penetrate the deep fasia close to their origin from the superficial veins and contains valves that when functioning normally, only allow blood to flow from the superficial veins to the deep veins. The perforating veins pass through the deep fascia at an oblique angle so that when muscle the deep fascia, the perforating veins are compressed. This also prevents blood from flowing from the deep to the superficial veins.

Deep veins of the lower limb
Deep veins contained within the vascular sheath with the artery, whose pulsations also help to compress and move blood in the veins.
The dorsal digital veins of the foot receive tributaries from the plantar venous arch and join to form common dorsal digital veins that terminate in the dorsal venous arch.
Medial and lateral plantar veins pass close to the arteries and after communicating with the great and small suphenous veins, form the posterior fibial veins posterior to the medical malleolus. The deep veins communicate with the superficial veins through perforating veins. Because of the effect of gravity, bloodflow is markedly reduced when a person stands quietly. During exercise blood received is propelled by muscular contraction to the femoral and then the internal iliac veins, flow in the reverse direction away from the heart or from the deep to the superficial veins is prevented if venous valves are competent.

Creation of flow within veins
Only three forces create movement of venous blood in the limbs.
1. Aretrial pressure across the capillary beds
2. Musculovenous pumps.
3. Gravity :- If the limb is elevated above the horizontal flow towards the heart occurs by simple gravitational downflow.

Disorderd venous function
Venous insufficiency, a state of inadequate venous return in the upright position and accompanied by venous hypertension, may occur in the following circumstances.
1. Deficient or defective valves in superficial veins, causing massive downflow:- See in simple varices veins.
2. Active venous thrombosis (acute deep vein thrombosis) with imapairment of musculovenous pumping mechanism.
3. Post-thrombotic Syndrome
Venous thrombosis causing obstruction or deformity in the venous circuits.
4. Loss of deep vein valve competence or replacement of the deep veins by enlarged, valves, collateral veins as occurs in post thrombotic states.
5. Valveless and abak vein Syndrome.
In born deficiency of deep vein valves or inherent weakness in the vein wall with valve failure.
6. Prolonged in activity of the muscles with the limbs in a dependent position, as in paralysis or disease states innibiting use of muscles.
Arteriovenous fistula by direct arterial in flow to the venous side can cause venous hypertension and the characteristic venotensive changes resulting from it.

Signs of venous abnormality in the lower limb with patient standing
1. Tortuosity
This is the most significiant visible sign of abnormality. This is mostly seen in superficial valve incompetence, where strong gravitational downflow occurs. High flow in a normal direction at increased pressure, intermiftently or continuously, will cause enlargement but seldom accompanied by tortousity.

2. Saccules on the veins
Since saphenous vein is too robust, seldom become tortous, instead one or more saccules may be seen or palpated along its length. Usually a saccule is immediately below valve cusps and which are leaking heavily and the gross turbulence this causes on coughing give rise to a characteristic, palpable thrill, readily confirmed by Doppler flowmetry and functional phelebography. The presence of a saccules is a clear indication of a incompetent valve.

3. Inky-blue-black veins
Varicose commonly become adherent to overlying skin and may so stretch it that the dark blue venous blood shows through very clearly. This fragile covering will be vulnerable to minor trauma which may cause heavy haemarrhage.

4. Distended Subdermal and intradermal venules
Extensive patterns of radiating venules are commonly seen around the ankle and on the foot (corona phlebectatica). These flares of veins indicate venous congestion with increased venous pressure. They occur more readily in the weakened tissues of the elderly and are not necessarly the precursons of ulceration. (These veins must be distingushed from small elustens of intradermal venules (thread or spider veins). Seen on the thigh or upper leg increasingly as middle age approaches these may signify underlying venous disorder.

5. Cough impulse
Varicose veins give a palpable impulse when the patient coughs, because of the absence of functioning valve between the abdomen and the vein, and it confirms incompetence in the valves of deep and superficial veins leading to this point.

6. Increased warmth in veins
Veins carrying a strong reversed flow of blood that has just emerged from a deep vein at true body temparature, as in simple varicose veins. This is valuable confirmation of the vein’s abnormal state. This sign is also seen in Arteriovenous fistula.
With the patient lying
Hollows and grooves in the elevated limb.
When the limb is elevated the veins wil empty and space occupied by large varicose veins becomes a hollow or a groove readly palpable or even visible.
The nature of varicose veins

Varicose veins, arise in 3 circumstances of unnatural flow.
I. Simple (or primary)
II. Secondary
III. Arteriovenous fistula

1. Simple (or primary) varicose veins
These occur only in the superficial veins of the lower limbs and are by far the most common variety of varicose veins. Such veins have no competent valves and are subject to substantial upright and moving. Due to inadequate valves.
2. Secondary varicose veins
Tortuisty is often seen in superficial veins carrying reversed flow as a part of collateral mechanism compensating for obstruction in a neighbouring deep vein. Tortousity is seen in normal veins.
Eg:- Suprapubic veins acting as collaterials to iliac vein oesophageal varices in portal hyperation.
3. Arteriovenous fistula
Tortuosity is often present in lesser veins inthe vicinity of an A.V. fistula but major veins leading from it enlarge without totuosity.

Signs of venous hypertension
Venous hypertension is a common consequence of venous disorder. Raised venous pressure cause an increase in capillary pressure & will cause characteristic changes in skin and subcuteneous tissues. These are mainly the result of excess capillary transudation carrying with it protein molecules and leading to deposition of fibrin which forms a barrier to nutritional exchange between capillaries and the surrounding tissues. Other substances are also extravasated including haemosiderin which eventually gives the characteristic brown skin pigmenation of venous hypertension.

Venotensive change
1. Swelling
Mainly due to oedema
2. Induration
A characteristic diffuse fibrosis in the subcutaneous tissues. These changes may be accentuated by fat necrosis and chronic inflammatory changes. The term “lipodermatosclerosis or liposclerosis are often used to describe induration due to venous disorder.
3. Pigmentation
Most characterstic change, due to accumulation of haemosiderin in the skin.
4. Ulceration
If the condition remain untreated, prograssive deterioration in skin nutrition leads to small areas of tissue death, to form an ulcer.
An venous ulcer will be surrounded by pigmented skin and atleast induration. In long standing ulcers the neibouring skin may also show a characteristic white scarring known as “atrophie blache”.
5. Eczema and dermatitis.
Skin is prone to eczema especially the pigmented area. Pruritus will be prominent.

Symptoms of venous disorder
(When venotensive changes are not present)
1. Distress and aching after prolonged standing. In women discomfort is most marked over a few days before menstruration.
2. Nocturnal cramps
Additional Symptoms when venotensive changes are present include

1. Pruritus – May be the early change
2. Increased discomfort
3. Venous claudication

Diagnosis
By clinical history and clinical examination
Clinical Tests
1. Brodie – Trendelenburg test
2. Tourniquet test
3. Perthe’s test
4. Modified Perths test
5. Scwartz test
6. Pralt’s test
7. Morrisey’s Cough impulse test
8. Fegan’s method
(to indicate the sites of perforators)

Special investigations
1. Phlebography
2. Ascending fuctional cinephiebography
3. Doppler ultrasonogram
4. Duplex imaging
5. Ultrasound and CT scan

Management
1. Reassurance
2. Use of elastic compression stockings (creep bandage)
3. Injection Sclerotherapy
4. Surgical treatment

Homoeopathic Medicines
Sulphur, Pulsatilla, Graphitis, Fluric acid, Millifolium, Hammamelis, Cale flur, Ambragrisea Vipera, Lycopodium, Bothrops, Lachesis, Carbo veg, Arnica.