Biomedical subjects
J T Hobbs
Publications and source records attributed to J T Hobbs.
Venous wall function in the pathogenesis of varicose veins.
Three theories have been proposed to explain the cause of varicose veins, citing three different factors as the primary cause: valvular incompetence, a weakness of the vein wall, and increased arterial inflow associated with multiple arteriovenous communications. This study was designed to determine the cause of varicose veins with respect to these three factors. Duplex scanning techniques were used to assess the venous valves, and simultaneous measurements of calf volume (strain-gauge plethysmography) and venous pressure made during venous occlusion plethysmography were used to determine the elasticity of the venous wall and the rate of arterial inflow. Fifty-one control legs and 36 legs with superficial venous insufficiency were examined. Risk factors were used to divide the control legs into two groups: low risk or normal (23 legs) and high risk (28 legs). The results obtained in the high-risk limbs demonstrated a significantly reduced vein wall elasticity (p less than 0.001) and increased arterial inflow (p less than 0.005) compared with the normal limbs, with no corresponding increase in the incidence of valvular incompetence. These results clearly suggest that the role of the venous valves in the development of varicose veins is secondary to changes in the elastic properties of the vein wall and the rate of arterial inflow.
ABC of vascular diseases. Varicose veins.
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Haemodynamic significance of incompetent calf perforating veins.
A total of 149 consecutive unselected patients (221 limbs) who presented with signs and symptoms of chronic venous problems (varicose veins with or without ankle oedema, skin changes and leg ulcers) have been studied by clinical examination, ascending deep to superficial venography, Doppler ultrasound and ambulatory venous pressure measurements. Of the limbs, 180 (82 per cent) had varicose veins without obstruction in the deep veins or reflux in the popliteal or femoral veins while 41 (18 per cent) had deep venous disease. Of the 180 limbs with 'primary' varicose veins 110 (60 per cent) did not have incompetent calf perforating veins (group A) while 70 (40 per cent) did (group B). On the basis of the ambulatory venous pressure after calf muscle exercise and the refilling time, the incompetent calf perforating veins of limbs in group B belonged to three subgroups of different haemodynamic significance. In 20 limbs (30 per cent) they were found to be of no haemodynamic significance, in 25 (35 per cent) of moderate haemodynamic significance and in 25 (35 per cent) of major haemodynamic significance. The last were, on clinical examination, indistinguishable from limbs with deep venous disease although they had patent deep veins with competent popliteal valves.
The pelvic congestion syndrome.
Perivulval varices appear during pregnancy and usually disappear after delivery but become more prominent with subsequent pregnancies. They may extend over the buttock and may be associated with recurrent leg varices. Some patients have extensive varices in the broad ligaments and present with the pelvic congestion syndrome. These patients have been shown to have grossly dilated ovarian veins. Elimination of this proximal incompetence relieves the symptoms.
Role of venous elasticity in the development of varicose veins.
A reduction in the 'elasticity' of the venous system has been proposed as a precursor of venous insufficiency, but the concept remains controversial. This study was designed to develop a method of assessing venous elasticity, and to use this method to investigate the aetiology of varicose veins. Simultaneous measurements of calf volume (determined using strain gauge plethysmography) and venous pressure (obtained via a dorsal foot vein) were made during venous occlusion plethysmography. The elastic modulus, K, defined as stress/strain when the veins are full, was calculated from the pressure/volume relationship. The elastic modulus was determined in 19 normal legs, 33 legs with superficial venous insufficiency, 16 legs with deep venous insufficiency, and 18 legs of a high risk group of volunteers or patients without varicose veins but with a strong history of factors associated with their development. The results showed a clear difference in elasticity between normal limbs and limbs with varicose veins, and also between normal limbs and high risk limbs. These results support the hypothesis that reduced elasticity has a role in the development of varicose veins and precedes the onset of valvular incompetence.
Evaluation of non-invasive and invasive methods in the assessment of short saphenous vein termination.
Surgery of the short saphenous vein is associated with a high recurrence rate because of variations in the anatomy or inadequate clinical examination. To prevent this, accurate definition of the pattern and level of termination of the saphenopopliteal junction and flush ligation is necessary. Clinical examination, Doppler ultrasound, duplex scanning and peroperative venography have been compared to assess the level of termination of the short saphenous vein. In all, 64 limbs of 46 patients were examined. In 39 limbs there was primary short saphenous incompetence, in 13 limbs there was recurrent short saphenous incompetence; in ten of these there was incompetence of the gastrocnemius vein. In 12 limbs a duplex scan did not demonstrate incompetence of the short saphenous vein or gastrocnemius vein. The accuracy of these methods when locating incompetence of the short saphenous vein to within 2 cm of the saphenopopliteal junction was 56 per cent for clinical examination, 64 per cent for Doppler ultrasound and 96 per cent for duplex scanning. When there was no saphenopopliteal junction (9 per cent), duplex scanning correctly detected the pattern of the incompetent vein. The apparent success of clinical examination was because the vein was not felt above the femoral intercondylar groove and 52 per cent of the veins terminated at this level. Duplex scanning is a non-invasive technique which is almost as accurate as venography and provides additional haemodynamic information about the incompetent veins by demonstrating the presence and extent of reflux.
A well-known 'phallacy' resurrected.
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Compression sclerotherapy in venous insufficiency.
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Graduated compression and its relation to venous refilling time.
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Peroperative venography to ensure accurate sapheno-popliteal vein ligation.
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The management of varicose veins.
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Surgery or sclerotherapy for varicose veins.
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Letter: Varicose veins in developing countries.
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A new waist-length lightweight elastic stocking.
This trial has clearly demonstrated that the new waist-length lightweight elastic stocking introduces advantages over the normal thigh-length lightweight elastic stocking, with regard to comfort and appearance, and over support tights by applying greater pressure. Since they conform to current fashion they are more easily accepted by women patients, who preferred them to the present thigh-length elastic hosiery.
Vulval phlebography in the pelvic congestion syndrome.
Twelve patients referred to a general surgeon with special interest in varicose veins were found to have vulval varices. All the patients were considered to be suffering from the pelvic congestion syndrome. Their radiological investigation by percutaneous vulval phlebography is described. It is suggested that patients with vulval varices should be examined radiologically by percutaneous vulval vein injection of contrast medium. It is postulated that pelvic vein thrombosis may precipitate the pelvic congestion syndrome. Whereas there is no established treatment of this syndrome, the radiological examination has proved helpful in planning the treatment of these patients.