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Biomedical subjects

S Renton

Publications and source records attributed to S Renton.

16 recordsLinked to original sources
PubMed2003

Aortic aneurysm replacement with Dacron graft in a 34 year old man. How long will the graft last?

A unique case of an abdominal aortic aneurysm replacement in a young man of Caribbean descent is presented. The initial working diagnosis was of a mycotic aneurysm, which has recently shown resurgence with intravenous drug abuse. Blood tests and subsequent biopsy ruled that out. There was also a clinical suspicion of a connective tissue abnormality. Histological examination of the aneurysm, skin biopsy, and blood tests also ruled out this possibility. The graft used in this patient was from a new generation of grafts. In the absence of any studies on such grafts, there is the question of long term durability of the graft.

Adult↗
PubMed2002

HR (Paroven, Venoruton; 0-(beta-hydroxyethyl)-rutosides) in venous hypertensive microangiopathy: a prospective, placebo-controlled, randomized trial.

UNLABELLED: The aim of this study was to demonstrate whether HR (Paroven-Venoruton; 0-(beta-hydroxyethyl)-rutosides), was effective in improving the microcirculation in venous hypertension and microangiopathy. Sixty patients with severe venous hypertension due to chronic venous insufficiency, ankle swelling, and lipodermatosclerosis were included. After informed consent, patients were randomized into a treatment group and a placebo group. Patients in the treatment group received oral HR (2 g/day for 8 weeks); those in the placebo group received a comparable placebo. RESULTS: The two groups were comparable for age and sex distribution. The mean age was 45 years (SD 9) in the treatment group (31 patients) and 45.5 (SD 10) in the placebo group (29 patients). There were no differences between the placebo and treatment groups at inclusion. There was no change between inclusion and measurements at 8 weeks in the placebo group. A significant decrease (P < 0.05) in flux at rest and rate of ankle swelling was observed in the treatment group. The decrease in capillary filtration was associated with improvement in signs and symptoms (P < 0.05). The difference in flux, sign and symptoms, and filtration was clinically important at 8 weeks in the treatment group when compared with the placebo group. No adverse effects were observed. CONCLUSION: Venous microangiopathy was improved by HR treatment.

Adult↗
PubMed2002

HR (Venoruton1000, Paroven, 0-[beta-hydroxyethyl]-rutosides) vs. Daflon 500 in chronic venous disease and microangiopathy: an independent prospective, controlled, randomized trial.

OBJECTIVES: The aim of this study was to demonstrate whether and how HR (Venoruton(1000), Paroven, 0-[beta-hydroxyethyl]-rutosides) and Daflon (diosmin, 500 mg) were comparatively effective in improving the microcirculation in venous hypertension and microangiopathy. METHODS: A group of 90 patients with severe venous hypertension due to chronic venous insufficiency, ankle swelling, and lipodermatosclerosis were included. After informed consent, patients were randomized into a Venoruton and a Daflon (DF) group: patients in the Venoruton group received oral HR (2 g/day for 8 weeks); those in the Daflon group received three 500-mg tablets daily every 8 hours. The two groups were comparable for age and sex distribution. The mean age was 41 years (SD +/- 11) in the Venoruton group (46 patients) and 41.3 (SD +/- 12) in the DF group (44 patients). RESULTS: There were no differences in microcirculatory parameters between the Venoruton and DF treatment groups at inclusion. There was no significant change between inclusion and measurements at 8 weeks in the DF group. In comparison, a significant decrease (P < .05) in RF (resting skin flux) and RAS (rate of ankle swelling) was observed in the Venoruton group (P < .001). The decrease in capillary filtration was associated with improvement in signs and symptoms (measured by an analogue scale line) (P < .05). Symptomatic improvement was clinically and statistically significant and important only in the Venoruton group. No side effects and no drop-outs were observed. CONCLUSION: Venous microangiopathy was improved by the treatment with Venoruton. The comparison with Daflon indicates that HR is comparatively more effective both on microcirculatory parameters and on signs and symptoms.

Adult↗
PubMed1997

Rational approach to combined carotid and ischaemic heart disease.

BACKGROUND: The management of patients with concomitant coronary and carotid artery disease remains a controversial subject. The aim of this review was to develop a rational plan for the management of such patients based on a review of the literature. METHOD AND RESULTS: A retrospective review was carried out of relevant papers derived from the Medline database from 1964 to 1996. CONCLUSION: The management of patients with concomitant coronary and carotid artery disease has not yet been put to the test in a properly designed and randomized multicentre trial. It is suggested that, until the results of such a trial are available, the rational approach to combined symptomatic disease is combined carotid endarterectomy and coronary artery bypass grafting (CABG). Combined surgery is also appropriate for patients with symptomatic carotid artery disease and significant but asymptomatic cardiac disease. At present there is inadequate evidence to promote carotid endarterectomy for asymptomatic disease in combination with CABG.

Carotid Artery Diseases↗
PubMed1996

Relative fasting hypoinsulinaemia and ultrasonically measured early arterial disease in type 2 diabetes. The SENDCAP Study Group, St. Mary's, Ealing, Northwick Park Diabetes Cardiovascular Disease Prevention Study.

Macrovasular disease is the most important cause of morbidity and mortality in Type 2 (non-insulin-dependent) diabetes. Dyslipidaemia and hyperinsulinaemia have been proposed as aetiological factors. This paper describes the interrelationships between fasting serum insulin, serum lipids, and the extent of ultrasonically measured early arterial disease in Type 2 diabetic subjects screened for entry into a prospective study set up to ascertain whether improving serum lipids can alter the progress of arterial disease in Type 2 diabetes. Measurements were made of the initima media thickness (IMT) in the carotid artery, and an arterial ultrasound score (AUS) based on appearances of both carotid and femoral arteries was calculated for 192 established Type 2 diabetic subjects, males and females, mean age 51 (range 35-66) years, median duration of diabetes 3.5 years, with no known cardiovascular disease. Multiple regression analysis showed that carotid IMT increased with age and was inversely related to serum insulin (variance accounted for, R2, = 8.8%, p = 0.0002). AUS increased with age and was related inversely to serum insulin, or to C-peptide when this was substituted in the model. In addition to age and serum insulin, AUS was positively associated with non-HDL cholesterol and negatively with HDL 3 cholesterol (R2 = 26%, p = 0.0001). Early thickening and damage to the arterial wall in Type 2 diabetes may be related to relative fasting hypoinsulinaemia.

Adult↗
PubMed1994

Serum lipids and apolipoproteins and their relationship with macrovascular disease in type 1 diabetes.

In order to examine the relationship between serum lipids and apolipoproteins and macrovascular disease in patients with Type 1 diabetes mellitus, 50 patients with Type 1 diabetes mellitus attending the diabetic clinics at St Mary's and St Charles' Hospitals, London were recruited into a cross-sectional study. B-mode ultrasound was used to measure intima-media thickness and define an arterial ultrasound score for each patient as a non-invasive indicator of atherosclerotic change. Intima-medial (i-m) thickness was significantly higher in those subjects with clinical evidence of macrovascular disease compared to those without macrovascular disease (0.865 +/- 0.191 vs 0.695 +/- 0.162 mm, p = 0.0038). In the study group there were significant correlations between i-m thickness and age (r = 0.65, p < 0.01), total serum cholesterol (r = 0.32, p < 0.01), and serum fibrinogen (r = 0.43, p < 0.01) but no other lipid or apolipoprotein variable. When i-m thickness was corrected for age there were significant correlations with total cholesterol (r = 0.43, p < 0.01) and LDL-cholesterol (r = 0.42, p < 0.01). Whereas total and LDL-cholesterol and serum fibrinogen concentrations were related to the extent of atherosclerotic disease by ultrasound techniques, there was no relationship with high density lipoprotein (HDL) or subfraction cholesterol concentrations. HDL-cholesterol may not be a useful marker for cardiovascular disease in Type 1 diabetes.

Adult↗
PubMed1994

The effect of hydroxyethylrutosides on capillary filtration in moderate venous hypertension: a double blind study.

The aim of this study was to evaluate the effect of hydroxyethylrutosides on capillary filtration in subjects with mild to moderate venous incompetence--superficial varicose veins and/or deep venous disease and ankle oedema--using the vacuum suction chamber (VSC) device applied to the internal perimalleolar region and the wheal vanishing (WV) time. Subjects entered in to the study were randomised to receive either hydroxyethylrutosides (1 g twice daily for 4 weeks) or placebo for four weeks. The two groups entering and completing the study were comparable. Microcirculatory parameters (laser-Doppler resting flux, the venoarteriolar response, transcutaneous PO2 and PCO2) remained constant during the four week study in both groups. The WV time, which was comparable in the two groups at the beginning of the study decreased significantly [from a median 55 min (interquartile 955 min), to a median 45 minutes (interquartile 65-40 min) in the treated group, p < 0.01]. No change was observed in the WV time in the placebo group. Subjective symptoms measured with an analogue scale improved following treatment with hydroxyethylrutosides [foot oedema (p < 0.005), ankle oedema (p < 0.001), and paraesthesia (p < 0.01)]; only night cramps were reported less in patients receiving the placebo (p < 0.05). In conclusion, the WV time can be used to assess the beneficial effect of therapy on capillary filtration in subjects with mild-moderate venous hypertension, even after a short period of treatment, and before other microcirculatory parameters change. Furthermore, the changes observed in WV time correlate well with an improvement in patients symptoms.

Ankle↗
PubMed1993

Measurement of the ultrasonic intima-media complex thickness in normal subjects.

PURPOSE: The evolution of atherosclerosis can be studied before development of symptomatic plaque by evaluating morphologic changes of the intima-media (I-M) complex, seen on high-resolution ultrasonography of the arterial wall. These qualitative changes require large alterations in vessel wall appearance to recognize progression of atherosclerosis. It has been suggested that measurement of the thickness of the I-M complex may be a quantitative and more sensitive method of assessing these early atherosclerotic changes. METHODS: High-resolution ultrasonography has been used to measure the thickness of the I-M complex in 140 symptom-free subjects. RESULTS: The mean thickness of the I-M complex of the common carotid arteries was linearly related to the age (r = 0.77; p < 0.001), pack-years of smoking (r = 0.39; p < 0.05), the systolic blood pressure (r = 0.51, p < 0.01), and to the arterial ultrasound score (r = 0.85). The arterial ultrasound score has previously been shown to correlate with the presence of asymptomatic myocardial ischemia and with the development of cardiovascular symptoms. The mean thickness of the I-M complex in subjects without plaque (in the common carotid or common femoral artery bifurcations) was significantly thinner than in subjects with plaque (p < 0.001). CONCLUSION: The thickness of the I-M complex of the common carotid arteries is a measure of the risk for the development of cardiovascular symptoms in symptom-free individuals.

Adolescent↗
PubMed1993

Noninvasive ultrasonic biopsy: evaluation of early arteriosclerotic lesions progression in normal asymptomatic, hyperlipidemic, and diabetic subjects.

Noninvasive ultrasonic biopsy (UB) is a method of detecting early arteriosclerotic changes by high-resolution ultrasound scanning of the carotid and femoral bifurcation. Six UB classes (scoring 0 to 10) have been identified in 2000 asymptomatic subjects and 600 vascular patients followed up for four years. The incidence of silent coronary ischemia (tested by effort test) and the occurrence of symptomatic events in four years are increased in advanced classes and with increasing UB score. The rate of progression (ROP) in four years to the next UB class has been defined in normal subjects (1.4% in class I, 3.1% in II, 10.7% in III, 17.9% in IV, and 79.2% in class V). In a group of 305 asymptomatic hyperlipidemic subjects and in a group of 269 diabetics the ROP (in four years) was significantly higher. Therefore ultrasonic biopsy is useful to identify subjects at risk of coronary ischemia and cardiovascular events and to follow up noninvasively the progression of arteriosclerosis.

Adult↗
PubMed1993

Screening asymptomatic subjects with subclinical arteriosclerotic lesions with arterial ultrasonic biopsy. The P.A.P. study.

Ultrasound Biopsy is a an effective screening method for detecting early, subclinical arteriosclerotic lesions. Carotid and femoral artery wall lesions are important markers of generalized cardiovascular disease. The evaluation of 4 arterial sites (both carotid and femoral arteries) gives a clue of the status of the whole cardiovascular system. In 27.9% of all patients the femoral lesions are present earlier or in a more advanced stage than carotid lesions. Different age groups have a different UB class distribution and score due to the progression with age of the disease. Early arterial lesions and small plaques are important indicators of silent coronary ischemia and cardiovascular events. The method has also an impact on patients' compliance. Subjects with early plaques shown by high resolution ultrasound are more impressed by this finding than by laboratory results.

Adolescent↗
PubMed1993

Evaluation of arteriosclerosis progression with ultrasonic biopsy and intima-media thickness measurements.

Noninvasive ultrasonic biopsy (UB) can be used to classify arteriosclerotic lesions and their progression in the carotid and femoral bifurcation. Six UB classes have been defined. The rate of progression (ROP) to the next UB class in four years has been defined in 1270 normal subjects: it was 1.4% from class I to class II, 3.1% from II to III, 10.7% from III to IV, 17.9% from IV to V and 79.2% from class V to VI. In high risk subjects (HRS)--305 hyperlipidemics, 269 diabetics and 381 hypertensives--the ROP in 4 years was significantly higher considering all classes. This finding was matched by a more significant increase in intima-media thickness (IMT) increase in HRS in comparison with normal subjects. In conclusion UB and IMT measurements can be used to monitor arteriosclerosis progression. HRS have a comparable increase in ROP and IMT in four years indicating rapid progression in comparison with normals. UB appear to be more effective in evaluating progression when plaques and wall irregularities make IMT measurements difficult.

Adult↗
PubMed1991

Impact of duplex scanning on vascular surgical practice.

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 placental insufficiency and portasystemic 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.

Aorta↗
PubMedDate not supplied

Arterial wall changes in type 2 diabetic subjects.

Arterial ultrasonic appearances using high resolution ultrasound were studied in 97 subjects with Type 2 diabetes and age- and sex-matched controls. The intima-media thickness of both common carotid arteries was measured 2 cm proximal to the bifurcation and the presence or absence of plaque on both common and femoral bifurcations was recorded. The mean intima-media thickness in subjects with diabetes was 0.82 +/- 0.22 mm while in the controls 0.66 +/- 0.13 mm (p < 0.001). Multiple regression in diabetic subjects only showed no correlation between age, sex, body mass index, smoking, duration of diabetes, systolic or diastolic blood pressure, cholesterol, HDL, LDL, triglycerides, HbA1 and the common carotid artery intima-media thickness. Type 2 diabetes is associated with increased intima-media thickness which has been found to be a marker of cardiovascular events in the general population.

Arteriosclerosis↗
PubMedDate not supplied

Capillary filtration in venous hypertension. Comparison between the vacuum suction chamber (VSC) device and straingauge phlethysmography.

To evaluate capillary filtration a group of normal subjects and two groups of subjects with venous incompetence (50 with deep and 50 with superficial incompetence) were studied with the vacuum suction chamber (VSC) device applied onto the internal perimalleolar region. This method was compared with straingauge plethysmography rate of ankle swelling (RAS). By the VSC the time taken for the weal to disappear (VSC time) was considered indicative of capillary filtration. The values obtained with the two methods were well related (r < 0.742) and there was a good separation between patients and normals. The separation between the two groups of patients was significantly better (p < 0.05) with the VSC time. In conclusion VSC time is a good indication of capillary filtration in comparison with straingauge plethysmography RAS. It may be used to assess variations in capillary filtration in venous hypertension and possibly to follow up the effects of treatments.

Adult↗
PubMedDate not supplied

Non-invasive ultrasonic biopsy in the classification of early arterial lesions and in the evaluation of the rate of progression of arteriosclerosis.

The evaluation of early arterial lesions and the follow-up of the progression of arteriosclerotic wall changes is possible with high resolution ultrasound. While dynamic (duplex scanning) data are suitable for the follow-up of advanced stenosis and plaques, the morphological evaluation performed using the technique of non-invasive ultrasonic biopsy may be used to follow-up early lesions and their progression. The data obtained by ultrasonic biopsy are related to the incidence of occult coronary ischemia and to the occurrence of cardiovascular events in 4 years. The rate of progression (ROP) to the next, more advanced UB class can be also evaluated by ultrasonic biopsy. It has been shown that in diabetic and hyperlipidemic subjects the ROP is higher. Also in interventional studies using lipid lowering agents (with a four-year follow-up) a reduction in ROP in treated asymptomatic hyperlipidemic subjects in comparison with controls has been documented. The combination of dynamic data and morphological data gives us a complete evaluation of the vascular system both for the assessment of single individuals and for large population studies.

Adult↗