Haemodynamic Performance of Low Strength Below Knee Graduated Elastic Compression Stockings in Health, Venous Disease, and Lymphoedema.

OBJECTIVE: To test the in vivo haemodynamic performance of graduated elastic compression (GEC) stockings using air-plethysmography (APG) in healthy volunteers (controls) and patients with varicose veins (VVs), post-thrombotic syndrome (PTS), or lymphoedema. Responsiveness data were used to determine which group benefited the most from GEC. METHODS: There were 12 patients per group compared using no compression, knee-length Class 1 (18-21 mmHg) compression, and Class 2 (23-32 mmHg) compression. Stocking/leg interface pressures (mmHg) were measured supine in two places using an air-sensor transducer. Stocking performance parameters, investigated before and after GEC, included the standard APG tests (working venous volume [wVV], venous filling index [VFI], venous drainage index [VDI], ejection fraction [EF]) and the occlusion plethysmography tests (incremental pressure causing the maximal increase in calf volume [IPMIV], outflow fraction [OF]). Results were expressed as median and interquartile range. RESULTS: Significant graduated compression was achieved in all four groups with higher interface pressures at the ankle. Only the VVs patients had a significant reduction in their wVV (without: 133 [109-146] vs. class1: 93 [74-113] mL) and the VFI (without: 4.6 [3-7.1] vs. class1: 3.1 [1.9-5] mL/s), both at p <.05. The IPMIV improved significantly in all groups except in the PTS group (p <.05). The OF improved only in the controls (without: 43 [38-51] vs. class1: 50 [48-53] %) and the VVs patients (without: 47 [39-58] vs. class1: 56 [50-64] %), both at p <.05. There were no significant differences in the VDI or the EF with GEC. Compression dose-response relationships were not observed. CONCLUSION: Patients with varicose veins improved the most, whereas those with PTS improved the least. Performance seemed to depend more on disease pathophysiology than compression strength. However, the lack of responsiveness to compression strength may be related to the low external pressures used. Stocking performance tests may have value in selecting those patients who benefit most from compression.

Quantifying the degree graduated elastic compression stockings enhance venous emptying.

OBJECTIVES: Graduated elastic compression (GEC) stockings reduce reflux and venous volume but their performance on augmenting venous return is unproven. The aim of this study was to quantify the ability of stockings to increase venous outflow from the leg. DESIGN: A prospective study comparing venous emptying without compression, versus class 1 (18-21 mmHg) and class 2 (23-32 mmHg) compression, using air-plethysmography (APG). METHODS: The right legs of 20 healthy subjects were studied supine. A 12-cm thigh-cuff was inflated in 10 mmHg steps from 0 to 80 mmHg while the corresponding increase in calf volume was recorded using the APG sensor calf-cuff. At the 80 mmHg plateau, the thigh-cuff was released suddenly to measure the unrestricted venous emptying. Venous return was assessed by: (a) identifying the incremental thigh-cuff pressure causing the maximal incremental increase in calf volume (IPMIV); (b) measuring the percentage reduction in calf volume in 1 second following thigh-cuff release - outflow fraction (OF); (c) time to empty 90% of the venous volume - venous emptying time (VET90). RESULTS: Median and inter-quartile range (IQR) baseline values of IPMIV, OF, and VET90 without compression were 20 mmHg (range: 20-30 mmHg), 44% (39-50%) and 13 seconds (8.8-15.9 seconds), respectively. These improved significantly with all stockings. The application of any stocking raised the median IPMIV by 30 mmHg. The change from a class 2 stocking compared with no stocking versus the change from a class 1 stocking to no stocking had a more pronounced effect (p < .005). After sudden thigh-cuff deflation, the venous emptying was 41-45% greater and 9-10 seconds faster with all stockings (p < .005). CONCLUSIONS: This is the first study to quantify the venous return of below-knee GEC stockings. Assessments of stockings in augmenting venous return may be of use as a way of optimising compression for individual patients unresponsive to standard conservative treatment.

Validation of a new duplex derived haemodynamic effectiveness score, the saphenous treatment score, in quantifying varicose vein treatments.

OBJECTIVES: To evaluate a duplex-derived score for varicose vein treatments using numerical values of haemodynamic effectiveness. DESIGN: The saphenous treatment score (STS) was developed prospectively to compare the effect of endovenous treatments on reflux within saphenous segments. PATIENTS: Sixty-six patients were randomised to endovenous laser ablation (EVLA) or ultrasound-guided foam sclerotherapy (UGFS) to the great saphenous vein (GSV). METHODS: Assessments included the Aberdeen varicose vein severity score (AVVSS), the venous clinical severity score (VCSS), the venous filling index (VFI) and the STS. RESULTS: A mean STS of 5.70 decreased to 3.30, P < .0005, post-treatment. The median (IQR) AVVSS, VCSS and VFI (ml/sec) decreased from 21.52(15.48) to 18.86(11.27), P = .14, from 6(4) to 3(4), P < .0005 and from 7.1(6.9) to 1.9(.9) P < .0005, respectively. In 15 patients requiring additional UGFS the mean STS values decreased from 5.8 to 4.13 and then to 2.6 P < .0005, respectively. The individual above and below knee mean treatment differences in STS on 38 EVLA and 28 UGFS patients were 1.92 and .87 (EVLA) compared to 1.57 and .29 (UGFS) P = .001, respectively. CONCLUSIONS: The STS has been shown to grade the haemodynamic effects of different treatments as well as ongoing treatments on the GSV.

Cost and effectiveness of laser with phlebectomies compared with foam sclerotherapy in superficial venous insufficiency. Early results of a randomised controlled trial.

OBJECTIVES: Quantify endovenous laser ablation (EVLA) with concurrent phlebectomies and ultrasound-guided foam sclerotherapy (UGFS) in cost and effectiveness at 3 weeks and 3 months. DESIGN: Single-centre, prospective, randomised controlled trial. PATIENTS: One hundred patients (100 legs), C(2-6), age 21-78, M:F 42:58, with primary varicose veins received either EVLA under local anaesthetic or UGFS. METHODS: Assessments included duplex, Aberdeen varicose vein questionnaire (AVVQ), venous clinical severity score (VCSS), venous filling index (VFI), visual analogue 7-day pain score and analgesia requirements. Additional treatments with UGFS were performed, if required. Micro-costing, using individually timed treatments, was based on consumables, staff pay and overheads. RESULTS: Changes in AVVQ, VCSS and VFI values (3 months) did not demonstrate any significant difference between groups. At 3 months, the above-knee GSV occlusion rate (without co-existing reflux) was not significantly different between the groups (74% vs 69%; EVLA vs UGFS; P = .596). Of the 9 haemodynamic failures in each group, 7 EVLA patients and 4 UGFS patients had co-existing cross-sectional above-knee GSV occlusion at some point. However, UGFS significantly outperformed EVLA in cost, treatment duration, pain, analgesia requirements and recovery. CONCLUSIONS: UGFS is 3.15 times less expensive than EVLA (£230.24 vs £724.72) with comparable effectiveness but 56% (versus 6%) required additional foam (ISRCTN:03080206).

The efficacy of a new stimulation technology to increase venous flow and prevent venous stasis.

OBJECTIVES: Electrical stimulation of calf muscles has been shown to be effective in prevention of DVT. The aim was to determine: (a) dependence of venous blood velocity and ejected volume on the rates of stimulated calf contractions: (b) clinical factors affecting efficacy in healthy individuals. METHODS: The maximum intensity stimulus tolerated was applied to calves of 24 volunteers. In popliteal veins, peak systolic velocities (PSV), ejected volume per individual stimulus (stroke volume SV) and ejected total volume flow per minute (TVF) of expelled blood were determined using ultrasound. Stimulation rates from 2 to 120 beats per minute (bpm) were applied. RESULTS: Mean baseline popliteal PSV was 10 cm/s. For stimulation rates between 2 and 8 bpm, the PSV was 10 times higher and reached 96-105 cm/s. Stroke volume (SV) per individual stimulus decreased in a similar fashion. With increasing rates of stimulation the TVF increased by a factor of 12 times (from 20 ml/min to 240 ml/min). CONCLUSION: Electrical stimulation is an effective method of activating the calf muscle pump. Enhancements of popliteal blood velocity and volume flow are key factors in the prevention of venous stasis and DVT. Further studies are justified to determine the stimulation rates in those with a compromised venous system.

Thrombophilia and venous thromboembolism. International consensus statement. Guidelines according to scientific evidence.

Thrombophilia is the term now used to describe predisposition to increased risk of venous and occasionally arterial thromboembolism due to hematological abnormalities. It can be a multifactorial disorder where congenital defects of anticoagulant or procoagulant factors may be combined with acquired hematological abnormalities. It should be considered in patients with a documented unexplained thrombotic episode or a positive family history. The aim of this document is to provide guidelines for investigation and management of patients with thrombophilia in the presence or absence of venous thromboembolism (VTE).

Medical management of patients with peripheral arterial disease.

Peripheral arterial disease (PAD) is one of the most frequent manifestations of atherosclerosis and is associated with atherosclerosis in the coronary and carotid arteries, leading to a highly increased incidence of cardiovascular events. Major risk factors of PAD are similar to those that lead to atherosclerosis in other vascular beds. However, there are differences in the power of individual risk factors in the different vascular territories. Cigarette smoking and diabetes mellitus represent the greatest risks of PAD. For prevention of the progression of PAD and accompanying cardiovascular events similar preventative measures are used as in coronary artery disease (CAD). However, recent data indicate that there are some differences in the efficacy of drugs used in the prevention of atherothrombotic events in PAD. Antiplatelet treatment is indicated in virtually all patients with PAD. In spite of the absence of hard evidence- based data on the long term efficacy of aspirin, it is still considered as a first line treatment and clopidogrel as an effective alternative. The new antiplatelet drugs ticagrelol and prasugrel also represent promising options for treatment of PAD. Statin therapy is indicated to achieve the target low density lipoprotein cholesterol level of ≤2.5 mmol/L (100 mg/dL) and there is emerging evidence that lower levels are more effective. Statins may also improve walking capacity. Antihypertensive treatment is indicated to achieve the goal blood pressure (<140/90 mmHg). All classes of antihypertensive drugs including beta-blockers are acceptable for treatment of hypertension in patients with PAD. Diabetic patients with PAD should reduce their glycosylated haemoglobin to ≤7%. As PAD patients represent the group with the highest risk of atherothrombotic events, these patients need the most intensive treatment and elimination of risk factors of atherosclerosis. These measures should be as comprehensive as those in patients with established coronary and cerebrovascular disease.

Significance of sonographic tissue and surface characteristics of carotid plaques.

BACKGROUND AND PURPOSE: Our hypothesis was that symptomatic and asymptomatic carotid plaques are different. The aim of this study was to identify the sonographic tissue and surface characteristics of plaques and their degree of stenosis that corresponded to these two clinical presentations. METHODS: We studied 81 symptomatic and 111 asymptomatic plaques (150 patients) having 50% to 99% stenosis on duplex scanning. These plaques were imaged on duplex and captured in a computer. We evaluated the gray-scale median (GSM) to distinguish hypoechoic (low GSM) from hyperechoic (high GSM) plaques, and the bending energy (BE), to distinguish plaques with irregular (high BE) versus smooth (low BE) surfaces. RESULTS: The symptomatic group corresponded to hypoechoic (median GSM, 4) and severely stenosed (median stenosis, 85%) plaques, whereas the asymptomatic group corresponded to hyperechoic (median GSM, 35) and moderately stenosed (median stenosis, 70%) plaques (P <.05 for both variables). The BE failed to separate the two groups; the mean BEs were 1.63 and 1.68 for the symptomatic and asymptomatic groups, respectively (P =.38). CONCLUSION: Our results suggest that echogenic characteristics and the degree of stenosis are the strongest predictors of carotid plaque behavior. The sonographic surface characteristics failed to qualify as an index of plaque instability.

Out of a recent CVI consensus: some features of a basic statement.

In March 1997 at the Abbaye des Vaux de Cernay, France, a multidisciplinary meeting of venous specialists, to do guidelines on venous management was held. Subsequently the faculty members revised the document and a consensus statement was published in Circulation, in November 2000, based on wide-ranging and authoritative research into the investigation of chronic venous insufficiency (CVI). The statement gives information on the epidemiology and pathophysiology of CVI including the changes in the major veins as well as in the microcirculation and the associated hematological changes. It sets out the methods used for morphologic and hemodynamic investigations into venous disease and for the study of the microcirculation stating their usefulness and limitations, and indicating their place in clinical practice and research. A section deals also with the rare venous malformations. It concludes with an application of the methods in the investigation on CVI based on the CEAP classification that gives a uniform way of reporting venous disorders. The document is intended both for the clinician and the researcher. A shortened version appears below.

Combined carotid endarterectomy and coronary artery bypass grafting. A literature review.

This is a review article on the management of patients with both carotid and coronary artery lesions. Most authors agree that patients with symptomatic coronary and symptomatic carotid disease should be offered a combined operation (same anaesthetic) in the presence of unstable angina or left main stem coronary disease and staged operations in the presence of stable angina. Patients with symptomatic coronary disease and asymptomatic severe (greater than 80% stenosis) carotid disease should be offered the staged procedure not for preventing perioperative but late stroke. This statement is tentative and not supported by hard data. It should be revised when the results of the multicentre randomised studies of asymptomatic carotid stenosis become available. A prospective randomised study is required in patients with symptomatic coronary and asymptomatic severe unilateral and bilateral carotid stenosis (greater than 80%) in order to determine whether surgery in the carotid decreases the incidence of late stroke. It cannot be overemphasised that the team that does the carotid endarterectomy should have a good track record of combined mortality and morbidity of less than 5% for patients with TIA's and less than 3% for patients with asymptomatic carotid disease.

Low molecular weight heparins in the initial treatment of deep vein thrombosis.

All major trials to-date provide strong evidence that, for the initial treatment of DVT, adjusted-dose LMWHs are at least as effective and safe as unfractionated heparin (UFH). When compared with UFH, LMWHs achieved better thrombus lysis and had less bleeding complications (21-91% risk reduction) and mortality (51% reduction). They also reduced the incidence of recurrent DVT and PE at 90 days follow-up while there was no need for monitoring. Despite these exciting findings however, long-term evaluation of mortality rate, recurrent venous thromboembolism, blood monitoring tests efficacy and thrombus propagation/reduction are open issues. Furthermore, venous haemodynamics have never been tested. There is an ongoing Canadian study today, aiming to determine LMWHs effectiveness in reducing death, recurrent venous thromboembolism and haemorrhagic complications; it is obvious however that further studies are needed. We must determine if a prolonged use of LMWHs (i.e. 90 days) is more effective in preventing the post-thrombotic sequelae, reducing also the incidence of haemorrhagic complications; we also need to know the nature of the haematological changes that develop and the relationship between these changes and the recurrence rate; and finally, we must identify effective blood tests to monitor this treatment.

Natural history of chronic bilateral internal carotid artery occlusion.

Chronic bilateral ICA occlusion was found in 15 of 3200 patients studied with duplex scanning during a six years period. Ten of these patients had a history of stroke. Mean follow-up was 28.9 months. Six patients died during follow-up, coexisting cardiac ischaemia being the major cause of death. Two patients suffered a stroke (one fatal) resulting in an annual stroke rate of 5.5%, three patients continued to have TIAs and 5 remained asymptomatic. Chronic bilateral ICA occlusion is not always associated with neurological deficit. Coronary ischaemia, more than stroke is the leading cause of death in these patients.

Risk factors associated with recurrent carotid stenosis.

The incidence of restenosis following carotid endarterectomy reported with duplex scanning has ranged from 6-19%. The aim of this study was to determine the importance of risk factors in the development of carotid stenosis following carotid endarterectomy. Two hundred-thirty patients who underwent carotid endarterectomy (nineteen bilateral carotid endarterectomies) and had complete follow-up with duplex scanning for at least one year have been studied between February 1983 and April 1989. Forty six patients developed restenosis (18.5% of carotid endarterectomies) whereas 184 patients did not restenose. All patients were studied for the following risk factors: age, sex, ischemic heart disease, smoking habit, family history of cardiovascular disease diabetes mellitus, hyperlipidemia and peripheral vascular disease. The incidence of ischemic heart disease, a positive family history of cardiovascular disease, hyperlipidemia and diabetes mellitus was significantly increased (p < 0.05) in patients with recurrent carotid stenosis (80.4%, 71.7%, 58.7%, 32.6% respectively) as compared to patients without a recurrent stenosis (55.7%, 33.5%, 31%, 10.5%). None of the above significant risk factors was strongly associated with early (< 2 years) carotid restenosis. There is an increased prevalence of clinical atherosclerotic risk factors such as family history of cardiovascular disease, diabetes mellitus, ischemic heart disease and hyperlipidemia in patients who develop carotid restenosis.

The effect of elastic stockings on the elasticity of varicose veins.

The aim of this study was to establish the long-term effect of graduated elastic compression on venous elasticity in patients with superficial or deep venous disease and to determine the possible relationship between elasticity and the duration of the disease. The elastic modulus of 29 patients, 19 with superficial vein incompetence and 10 with deep vein incompetence was assessed by the simultaneous measurement of calf volume (determined using strain gauge) and venous pressure (obtained via a dorsal foot vein) during venous occlusion. The measurements were obtained before and after 4 weeks of elastic compression stockings. The elastic modulus K, was defined as stress/strain when the veins were full and was calculated from the pressure/volume relationship. The results show a clear difference in elasticity before and after elastic stockings. Two groups of patients were identified: group 1 with increased elasticity and group 2 with decreased elasticity. There was a negative linear relationship (r = 0.88) between increase in elasticity after treatment and duration of venous disease.

Complement activation in atherosclerosis: effect of angiography and surgery.

Complement activation in the plasma of patients with severe atherosclerosis (arterial occlusive or aneurysmatic disease) was investigated in this study. The effects of angiography and reconstructive arterial surgery (RAS) were also assessed. Atherosclerosis was not found to be associated with systemic complement activation. Angiography resulted in high levels of C3 breakdown products. Surgery caused a significant degree of systemic complement activation in both patients with atherosclerosis and controls. Post-operative levels of C3 breakdown products were significantly higher in atheromatic patients than in controls, most likely due to the insertion of dacron arterial prostheses in the first group.

How "gold" is the standard? Interobservers' variation on venograms.

BACKGROUND: The aim of this study was to determine the degree of agreement between radiologists having different levels of experience, in reporting 151 venograms independently. It was also aimed to assess whether the degree of disagreement would have influenced the final outcome of a thromboprophylactic study and the decision to anticoagulate the patients. METHODS: Seventy-eight patients undergoing total hip replacement had bilateral venography on postoperative days 8-12. Patients were allocated to receive either a low molecular weight heparin (enoxaparin) with or without TED stockings or a placebo Each of the 151 venograms obtained has been reported on four times. RESULTS: The overall incidence of deep venous thrombosis was 42% (33 of 78 patients). The range of the Kappa value of each radiologist versus the others was 0.568 to 0.669. There was a significant decrease in the incidence of deep venous thrombosis in the treatment versus the placebo groups. On an intention to treat all diagnosed thrombi, a difference of up to 16% was demonstrated between the report of individual radiologists and the panel. This difference was reduced to 8% when only thrombi proximal to the calf were considered clinically significant. CONCLUSIONS: These differences reflect the radiologist's experience and frequency of reporting on venograms and should be taken into account when studies for thromboprophylaxis are planned.

Carotid plaque echogenicity and types of silent CT-brain infarcts. Is there an association in patients with asymptomatic carotid stenosis?

BACKGROUND: The aim of this study was to identify the differences in echogenicity and the degree of stenosis of asymptomatic carotid plaques associated with different types of ipsilateral silent CT-brain infarcts. METHODS: Some 273 asymptomatic carotid plaques (218 patients) causing 50 to 99% stenosis were studied with high-resolution ultrasound. B-mode images were digitised and normalised by assigning certain grey values to blood and adventitia. The grey scale median (GSM) of the plaque in the normalised image was used to quantify echogenicity. Every patient had a CT-brain scan which an independent neuroradiologist read. The presence of 1) non-lacunar and 2) lacunar silent CT-brain infarcts ipsilateral to the carotid plaque was noted. RESULTS: The mean GSM of plaques associated with non-lacunar silent CT-brain infarcts was 19.6, of plaques associated with lacunar infarcts was 35.5 and of those associated with no infarcts was 32 (p=0.008, ANOVA). The mean degree of stenosis was 79%, 72% and 73% respectively (p = 0.1, ANOVA). Plaque echogenicity (p = 0.007) and not the degree of stenosis (p = 0.07) predicted the presence of non-lacunar silent CT-brain infarcts (logistic regression). CONCLUSIONS: Carotid bifurcation plaques, which are associated with non-lacunar silent CT-brain infarcts, are significantly more hypoechoic than those associated with lacunar or no infarcts. Plaques associated with lacunar silent infarcts and no infarcts have the same echogenicity and degree of stenosis. These findings suggest an embologenic mechanism of non-lacunar silent CT-brain infarcts that may have prognostic implications in patients with asymptomatic carotid stenosis. Prospective studies of asymptomatic carotid stenosis should assess the significance of 1) plaque echogenicity and 2) the presence of different types of silent CT-brain infarcts and atheroembolic stroke.

Brain CT infarction in patients with carotid atheroma. Does it predict a future event?

BACKGROUND: The aim of the present study was to investigate the predictive value for subsequent stroke of different patterns of brain CT infarction in patients with carotid atheroma. METHODS: Prospective study on 138 patients, with 138 carotid plaques, having, on presentation, a greater than 50 percent stenosis on duplex scanning and associated with an ipsilateral (to the plaque) amaurosis fugax (AF), hemispheric transient ischaemic attack (HTIA) or which were asymptomatic. This carotid artery defined the side of interest. All patients had a brain CT scan on presentation and subsequently were followed for a period of 1-5 years (mean 3.14). The baseline CT neurovascular findings on the side of interest were classified as pattern A (discrete subcortical and cortical infarctions), pattern B (haemodynamic infarctions, widespread white matter lesions, basal ganglia infarctions and lacunae) and normal CT. RESULTS: On follow-up, 5/27 (18.5 percent) of patients with pattern A, 4/38 (10.5 percent) with pattern B and 3/73 (4.1 percent) with normal CT appearance developed stroke in the hemisphere of interest (Cox regression: p=0.02). CONCLUSIONS: Pattern A confers an unfavourable prognosis in patients with carotid atheroma who are either asymptomatic or presented with amaurosis fugax or hemispheric transient ischaemic attacks.