Peripheral Vascular Disease(3)

Peripheral Vascular Disease(3) Guo Xueli ( 郭学利 ) Dept. Vascular Surgery, First Affiliated Hospital

Veins The most important disease processes affecting veins are two: varicosity and thrombosis

Varicose vein A varicose vein ---dilated, lengthened and tortuous It’s reason---increased pressure in the lumen of the vein, which stretches the vein wall. Stretching in the transverse axis ---dilatation of the vein Stretching in the longitudinal direction ---to become tortuous in order to accommodate its additional length

The causes of the increased pressure in the lumen of the vein: the aetiology differs--- according to the site and underlying pathology Vein in the submucosa of the lower end of the oesophagus(oesophageal varices) ---increased pressure in the portal venous system, due to cirrhosis etc.

Vein in the lower limbs---their valves become functionless (incompetent) The incompetent valve ---commonly at the termination of the long saphenous vein. ---sometimes at a site lower down the limb

Varicose vein in the lower limbs #an extremely common condition in European and American #uncommon in the Eastern countries ---the most likely explanation: the inhabitants have better veins.

Aetiology the most common lesion ---an incompetent (functionless) valve such cases---primary varicose vein, and constitute the vast majority of cases. secondary varicose vein---any causes of venous obstruction, e.g. tumour or pregnancy, and thrombosis of the deep veins. varicose veins in children and adolescents ---due to a congenital arteriovenous fistula or an extensive cavernous haemangioma.

Pathology of primary varicose vein In the upright position: 1.With each muscle contraction, blood is bumped upward and prevented from returning by the valves in the veins. 2.the pressure in the deep vein---reduced 3.blood in the superficial veins to empty into ---the deep vein, ready to be pumped upwards with the the next muscle contraction.

The valves in the superficial veins ensure that 1.only a short segment---empty through the corresponding perforating vein 2.widespread transfer of blood from superficial to deep vein---is prevented Extensive incompetence in the superficial valves blood to spill over from deep veins---at high level down the superficial veins Finally to enter the deep vein---at lower level these vein fall slack after muscle contraction

Such a retrograde circuit---based on an incompetent long or short saphenous vein. its upper end ---the source its main stem and branches---the pathway of incompetence one or more perforating vein---reentry points #removal of the source and the pathway of incompetence #enlarged reentry points(the perforators)---to be closed off

The main valves: 1.the termination of the long saphenous vein into the femoral vein. 2. the termination of the short saphenous vein into the popliteal vein. 3.the mid-thigh 4.on either side of the tibia and fibula where there are communication (perforators) passing through openings in the deep fascia above the ankle.

Symptoms #a tired and aching sensation ---in the leg, specially the calf, towards the evening. #itching of the skin over the varices

Examination The varicosities ---most commonly distributed along the course of the long saphenous vein ---less often, the short saphenous vein Identifying the location of the incompetent valve to identify the exact location ---ligation at exact sites, to abolish the retrograde flow of blood.

Selective occlusion (Trendelenberg) test (Valves functional test) 1.lies down and the limb is elevated to empty the veins. 2.the suspected pathway of incompetence is selectively occluded by compression with fingertips. 3.stands up and the varicose is observed. After a few seconds the compression is removed.

The vein fills promptly only at this stage ---the varicose vein fills by down flow So its valves---incompetent, the test---positive This test ---great diagnostic value Positive---accurately identify simple(primary) varicose veins Negative --- to look for the real source of incompetence

Testing for patency of the deep venous system before any surgical treatment---to know whether or not the deep venous system is patent. Selective perthes’ test 1.stands up so that the vein are well filled 2.the suspected pathway of incompetence--compressed with fingertips or a tourniquet . 3.the patient asked to rise on his toes---10 times.

The veins---visibly less prominent and soft The test---positive the deep vein pumping mechanism---functioning satisfactorily, fault--- in the superficial vein. Directional Doppler flowmetry ---to found the downflow Photoplethysmography ---to determine the venous refilling time incompetent valves---shortened

Ultrasonography---to found the downflow Venography---to found the downflow Treatment Varicose veins without venotensive changes treatment---cosmetic, symptomatic or definitive cosmetic method varicose veins---appropriate make-up or elastic support stockings

Symptomatic method heaviness or tiredness---relieved by elastic stockings and elevation of the limbs whenever Definitive method ---sclerotherapy or surgery Compression sclerotherapy only a few minor varicosities ---by injecting a sclerosing agent in solution, which causes thrombosis

The resultant fibrosis---the vein to shrink down in size, or even get obliterated. Surgical treatment the first necessary --- to know the sites of the incompetent superficial valves ---to know whether the deep vein are patent or not

1.the deep vein---patent, the deep valves and perforators---competent surgical results---very good 2. the deep vein---patent, the deep valves--competent, but perforators---incompetent surgical results---reasonable 3. the deep vein---obstruction superficial venous ligation and stripping ---not be carried out because a marked worsening of the situation ---usually occurs

#The basic principle of the operative treatment is the ligation 1.incompetence at the sapheno-femoral junction--ligation at this site, the termination of long saphenous vein. 2.saphenopopliteal ligation, the termination of short saphenous vein. 3.incompetence perforating veins are individually located by tourniquet tests and marked;next isolated by dissection and ligated. Not to damage or destroy normal competent saphenous veins---for coronary bypass operation

#Stripping Apart from ligation, the varicose vein---may by excised. Complications of varicose vein: Thrombophlebitis ---red and tender. elastic bandage ---applied over foam rubber pads. Eczema ---the patient scratches the skin which itches. An ointment containing hydrocortisone or zinc oxide and coal tar

Haemorrhage---a varicose vein may rupture and bleed furiously. #Press the bleeding point. #A bandage to be applied over a sterile gauze pad. #The leg should be elevated over 1 or 2 pillows. to elevate the leg without compressing the bleeding point---dangerous; air can enter the vein---air embolism

Venous ulcer(Gravitational ulcer,Varicose ulcer) ---chronic, tend to recur, and cause considerable disability ---follow either varicose veins or deep thrombosis The cause---venous stasis, results in---local anoxia and oedema. ---signs:dermatitis, brown discoloration, thickening of skin and oedema. ---the site:lies on the anteromedial surface of the tibia just above the medial malleolus.

Syphilis---must be excluded by serological tests Atherosclerotic ischaemia---by checking the peripheral pulses The Doppler ultrasound---may be employed Malignant change---a long-standing ulcer (Marjolin’s ulcer) The pathophysiology---not fully understood In a patient--- the high venous pressure in the deep vein transmitted to the superficial venous system ---extravasation of plasma and blood cell, the subcutaneous tissue---firm with a leathery feel.

Venous ulcer heal promptly---after ambulatory treatment or ligation operations Post-thrombotic ulcers---to be refractory to treatment---require bed-rest and skin grafting The bisgaard method--The limb is elevated, passive and active movements. A firm elastic bandage is next applied from the base of the toes to the knee and the patient encouraged to walk. Movements in walking alternatively stretch and relax the bandage and produce a venous pumping effect.

The treatment of incompetent perforators subfascial ligation---ligation under the deep fascia, a theoretically sound procedure. ---employed by some abandoned by others

Thrombosis The main factors: 1.Change in the vessel wall, usually damage to the endothelium, as in injury or inflammation. 2.Diminished rate of blood flow, as after operation. 3.increased coagulability of blood, as in infections and after haemorrhage.

The pathological effects of thrombosis 1.locally, the clot---dissolved and the vein--recanalized. Alternatively, the clot---organize into fibrous tissue. specially the thrombus---infected, an abscess--form, or pyaemia---occur due to systemic spread of the infection. in the pelvic veins a clot---calcifies, may look like a stone.

2. Distally the vein---remains blocked, a collateral circulation---soon opens up, by the appearance of tortuous superficial veins. 3. Proximally the clot---extend into the larger veins a portion of the thrombus---become detached---get lodged in a branch of the pulmonary artery--pulmonary infarction.

an infected thrombus---lodged in the portal vein---the formation of abscesses in the liver (pylephlebitis) Thrombosis in the superficial veins--commonly accompanied by inflammation (thrombophlebitis), while in the deep veins---no phlebothrombosis.

Superficial venous thrombosis(Thrombophlebitis) Occur in the following: 1.in a grossly varicose vein 2.in occult malignant neoplasms 3.in local trauma 4.in a vein cannulated for infusion 5.in polycythaemia and thromboangiitis obliterans

Clinical feature at the site of the vein ---a painful, red and tender cord Treatment thrombophlebitis---below the knee usually self-limiting, the risk of thromboembolism---minimal anticoagulation---not needed thrombophlebitis---above the knee embolization---occur the patients---closely observed for cephalad progression of thrombus

Bed rest and a crepe bandage Aspirin---relieves pain ---reduces the coagulability of the blood An abscess---be drained, along with proximal and distal ligation of the vein Anticoagulation ---to prevent pulmonary embolism

Deep vein thrombosis (Phlebothrombosis) the thrombus---to embolize to the lungs half the patients---no symptoms the most common---the pelvic and calf veins Its cause: 1.the intima is damaged(e.g. in trauma) 2.the circulation of the blood is sluggish (e.g. major operation or debilitating illness) 3.the blood is rendered more coaguable(e.g. operation) More than one factor---thrombosis increased

Postoperative thrombosis ---common in middle aged and elderly person, in the obese, and after operation on the hip and malignancies. The thrombosis 1.starts in a tributary of a main vein(the circulation is sluggish) 2.extends proximally to the main vein(the faster bloodstream) 3.break off a portion---lodges in the pulmonary vasculature---a pulmonary embolus

‘White leg’ and ‘blue leg’ A length of deep femoral vein---thrombosed, oedema and painful venous congestion in the lower limb. If the lymphatics---inflamed, a more pronounced and persistent swelling (phlegmasia alba dolens---‘white leg’ ) If extensive thrombosis of the iliac and pelvic vein---infarction affect parts of the lower limb(‘blue leg’)

Clinical findings #half the patients---no symptoms #a dull ache, a tight feeling, or frank pain in the calf #slight edema and fever The foot is passively dorsiflexed---pain in the calf -----Homan’s sign After extensive major operation, the calves should be examined every day for tenderness.

Diagnostic tests Venography ---the most specific test Contrast medium is injected into a vein to demonstrate the venous drainage---the popliteal, femoral and iliac vein. Doppler ---a practical, non-invasive method of assessment of blood flow. Plethysmography---useful non-invasive technique Magnetic resonance imaging---a reliable method

Management of deep vein thrombosis Prevention Before operation: to stop oral contraceptives---prone to develop venous thrombosis after operation a over-weight patient---reduce his weight elderly patients---mobilization heparin---subcutaneously 2hrs before operation ---be avoided in operation

During operation the heel---be elevated on foam rubber pads the leg---be elevated and massaged at the end of the operation After operation #massage and active leg movement---be prescribed and supervised, and dehydration corrected. #get onto his feet as early as possible #low dose heparin #dextran---inhibiting platelet adhesion

Treatment 1.the limb---be bandaged using crepe bandages bed rest advised---until the local signs subside 2.Anticoagulation heparin in combination with phenindione---to prevent the propagation of the original thrombus and the development of the new thrombi. 3.Fibrinolytics streptokinase and recombinant tissue plasminogen activator---lyse upto 70% of thrombi

Pulmonary embolism Placing a Greenfield or similar filter in the inferior vena cava---to prevent any dislodged thrombus, allow the flow of blood upwards through its interstices.

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