Search

A number of new studies have provided evidence which suggests that carotid plaque surface characteristics and internal structure, as seen on ultrasonography, contribute to the development of cerebrovascular endpoints. This review is a critical presentation of the evidence that has emerged so far supporting the hypothesis that the ultra-sonographic morphology of the carotid plaque may be an independent variable in predicting the risk of stroke. It is concluded that Ultrasonographic plaque morphology should be used together with other local risk factors in prospective natural history studies which aim to identify a subgroup of patients at high risk of stroke.

This review outlines the development of duplex scanning over the past 15 years and its value not only in vascular medicine and surgery but also in the field of transplantation and obstetrics. It is now the first line of investigation of patients with symptomatic carotid bifurcation disease and those with clinically suspected acute deep venous thrombosis. It is also an established method of femoropopliteal and femorodistal arterial graft surveillance, determination of the extent and cause of chronic venous insufficiency, detection of placentat insufficiency and porta systemic shunt patency, early transplant monitoring, as well as of detecting an arterial stenosis suitable for angioplasty. In addition, it is developing into the method of choice for the initial investigation of patients with suspected mesenteric or renal artery stenosis. The accuracy of duplex scanning, avoiding further unnecessary invasive and expensive diagnostic procedures, makes it one of the most cost-effective investigations ever introduced into clinical practice. Also, when used as a screening technique in arterial and venous disease, it selects those patients who need more invasive procedures such as angiography. This helps to reduce waiting lists of patients requiring investigation, and better directs limited resources to treatment rather than investigation.

This review examines the role of graduated elastic compression stockings in the prevention of postoperative deep vein thrombosis. Used alone compression stockings reduce the incidence of postoperative deep vein thrombosis by approximately 60 per cent and when used in combination with other preventive methods, such as low dose heparin or intermittent calf compression, they further reduce the incidence by up to 85 per cent.

Background Perioperative mortality, graft failure and limitations of balloon angioplasty mitigate against active intervention for claudication. With the exception of exercise programmes, conservative treatments yield modest results. Intermittent pneumatic compression (IPC) of the foot used daily for over 3 months enhances significantly the walking ability and pressure indices of stable claudicants. This prospective randomized study evaluated the effects of IPC of the foot and calf simultaneously (IPCfoot + calf) on the walking ability, arterial haemodynamics and quality of life of patients with intermittent claudication. Methods Forty-one stable claudicants, meeting stringent inclusion and exclusion criteria, were randomized to receive either IPCfoot + calf and 75 mg aspirin (group 1; n = 21) or 75 mg aspirin alone (group 2; n = 20), with stratification for diabetes and smoking. Groups matched for age, sex, initial (ICD) and absolute (ACD) claudication distance, ankle: brachial pressure index (ABPI), popliteal artery flow (Q) and quality of life (Short Form (SF) 36 questionnaire). IPCfoot + calf (120 mmHg, three cycles per min, inflation 4 s, proximal inflate delay 1 s) was used for 2·5 h daily for 5 months consecutively. Both groups were advised to exercise unsupervised. Evaluation of patients, after randomization, included: (a) ICD and ACD on a treadmill, (b) resting and postexercise ABPIs, (c) Q using duplex imaging, and (d) quality of life. Study time-points were: baseline and 1, 2, 3, 4, 5 and 17 months. Compliance was assessed by means of a log book. Non-parametric statistical analysis was used (Wilcoxon and Mann–Whitney tests). Results After 5 months of IPCfoot + calf median ICD, ACD, resting and postexercise ABPI in group 1 increased by 197, 212, 17 and 64 per cent (all P < 0·001) respectively; changes in group 2 were all non-significant (P > 0·1). On intergroup comparison at 5 months, patients in group 1 were better than those in group 2 in terms of ICD, ACD, resting and postexercise ABPI (all P < 0·01). Q changes within this period were not significant in either group; neither were intergroup Q differences (P > 0·1). Associated changes in the quality of life within group 1 at the end of month 5 were significant; non-significant changes were noted in group 2. At 5 months patients in group 1 enjoyed a better quality of life than those in group 2 (P < 0·01). IPCfoot + calf use did not result in any complications. The daily IPCfoot + calf compliance (2·5 h per day) was greater than 82 per cent in the first month and greater than 85 per cent in months 2–5. One year after the end of IPCfoot + calf application, patients in group 1 maintained the improved ABPI and walking benefit. Conclusion IPCfoot + calf emerged as an effective, high-compliance, uncomplicated method for improving the walking ability and pressure indices in patients with stable claudication, with a confirmed durable outcome. These changes are associated with a significant improvement in all aspects of quality of life evaluated by the SF-36. Despite a limited benefit noted in some individuals, unsupervised exercise had a non-significant impact overall.

Background Transcranial Doppler (TCD) ultrasonography can detect evidence of collateral flow across the anterior communicating artery and/or the posterior communicating artery, which occurs when there is significant alteration of ‘inflow’ to the brain. The aim of the study was to determine the blood flow velocity produced by a carotid stenosis which produces this haemodynamic effect on the cerebral circulation and evokes collateral circulation. Methods Forty-eight patients with varying degrees of carotid stenosis (10 per cent to occlusion) who underwent both carotid duplex and TCD examination were reviewed. An ATL HDI 3000 ultrasound system was used for the carotid and TCD studies. The carotid examination recorded peak-systolic velocity (PSV) and end-diastolic velocity (EDV) in the carotid systems bilaterally. TCD recorded Doppler spectra from the bilateral middle cerebral, anterior cerebral, posterior cerebral, intracranial vertebral and basilar arteries. Collateral flow was assessed in two ways: ‘intracranial crossover’ collateral and ‘posterior to anterior’ collateral. Each internal carotid artery (ICA), together with the ipsilateral hemisphere, was analysed for the presence or absence of collateral flow. Data were expressed as mean(s.e.m.). Results The PSV of the group with collateral circulation was 472(14) cm s–1 and that of the group without collateral flow was 164(3) cm s–1 (P < 0·0001, Mann–Whitney test). The respective EDVs were 158(13) and 58(7) cm s–1(P < 0·0001). Conclusion PSVs and EDVs in the ICA, in conjunction with collateral flow measured by TCD, are indicators of a haemodynamically significant carotid lesion, and provide more information than two-dimensional imaging studies. In the future, parameters set by combining carotid duplex and TCD investigations may represent the ‘gold standard’ for evaluation of cerebral blood flow.

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 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.

Air-plethysmography has been used to measure, in ml and in ml 100 ml−1 of tissue, the blood volume that filled the leg veins on changing posture from the recumbent position to standing. The venous filling index (VFI) (average filling range) was measured in ml s−1 and in ml 100 ml−1 min−1. We studied 24 normal legs (N), 21 with primary varicose veins without chronic swelling, skin changes (liposclerosis, eczema, pigmentation) or ulceration (PVV) and 59 with chronic swelling and/or skin changes and/or ulceration; of these 59 legs, 31 had primary varicose veins (PVV/S) and 28 had popliteal reflux (PR). The classification was done according to clinical examination, Duplex scanning, ambulatory venous pressure measurements and venography. There was an increased incidence of sequelae with increasing values of VFI. The incidence of these sequelae was irrespective of whether reflux was in the deep or in the superficial veins. VFI is a practical non-invasive measurement of reflux. It should be used to study the effect of therapy and particularly to evaluate new reconstructive procedures designed to abolish reflux in the deep veins.

Although incompetent thigh perforating veins are considered to be a common cause of recurrence of varicose veins after high saphenous ligation, the number and distribution of such incompetent veins have not been reported. The aim of the study was to determine the number and anatomical distribution of incompetent thigh perforating veins. Sixty-five limbs in 48 patients with varicose veins who were found to have incompetent thigh perforating veins on ascending deep to superficial venography were studied. In 80 per cent of patients one incompetent thigh perforating vein was found and in 20 per cent more than one was found. Concomitant incompetent calf perforating veins were found in 92 per cent of the limbs studied. The incompetent thigh perforating veins were found to occur anywhere in the thigh, from the upper edge of the patella to a few centimetres below the saphenofemoral junction. The majority (71 per cent) were found in the middle third of the thigh. All incompetent thigh perforating veins were communicating with the long saphenous vein, including those in five patients with incomplete stripping. The surgeon should be aware of incompetent thigh perforating veins which may be multiple and occur at any site on the medial aspect of the thigh.

A series of 245 patients was operated upon for abdominal aortic aneurysm during the years 1969–77, of whom 162 were elective cases while in 83 the aneurysm was leaking or had ruptrued. The hospital mortality for the latter group fell from 77 per cent at the beginning of the study period to 30 per cent at the end. For elective operations, hospital mortality averaged 9·3 per cent, though during the last 2 years there were no deaths in the 51 consecutive cases. Operative methods and post operative treatment changed during the years of the study, with fewere excision-replacement grafts and greater use of the inlay technique, most of the latter being simple unbrached Dacron tubes. Early graft infection, the most important and serious surgical complication, caused 9 deaths, an overall incidence of 3·7 per cent, of which 8 were in patients who received no perioperative antibiotics and only I among the patients who did receive them. All deaths were in the inlay group. The reasons for this are discussed. Since July 1976 Perioperative antibiotic treatment has been routine for all arterial prosthetic graft patients in our hospital.

A venographic technique for studying stasis in the deep veins of the legs of conscious patients is described. A second technique involving the clearance of radioactive material from the veins has been developed for use during operation. The results of the two methods correlate closely. There is considerable stasis of the blood, particularly in the soleal veins, in conscious patients with the legs horizontal, and it is prolonged considerably during surgery. Using these new techniques the effectiveness of various methods said to prevent stasis has been assessed.

The effect of local controlled cooling on the digital systolic blood pressure in the hand was studied in 25 healthy volunteers and 25 patients with Raynaud's syndrome. Arterial systolic pressure was indirectly measured using a digital cuff over the proximal phalanx and a photoplethysmographic probe over the digital pulp to detect pulsation. Pressures were measured after occlusion of the circulation (cuff at 180 mmHg) for 5 minutes with water circulating initially at 30°C and then at 10°C. An airfilled cuff was used simultaneously on a control finger. The digital systolic pressure at 10°C in the patients was significantly lower (P < 0·001 Mann–Whitney U test) than in the normal volunteers whilst calculation of the percentage change in pressure induced by cooling the digit to 10°C allowed complete separation between both groups. The range in the controls was +2 per cent to −26 per cent and in the patients, −33 per cent to −100 per cent. The test gives reproducible results (coefficient of variation 5–11 per cent) and offers an objective method of identifying patients with excessive vasospasm due to a cold stimulus. It may prove useful in studying natural history and the effect of drug therapy.

In a study of 50 patients who had undergone prostatectomy the incidence of deep-vein thrombosis was measured, using the 125I-fibrinogen test. Of these, 12 (24 per cent) developed deep-vein thrombosis. This preliminary study showed that in patients who had had a transurethral resection the incidence of deep-vein thrombosis was 6·8 per cent, while in patients who had had a retropubic prostatectomy it was 47·6 per cent.