PubMed Health⌕ Search

Biomedical subjects

J Dormandy

Publications and source records attributed to J Dormandy.

At least 19 recordsLinked to original sources
PubMed2006

The prevalence of thrombophilia in patients with symptomatic peripheral vascular disease.

BACKGROUND: The aim of this prospective study was to establish the prevalence of thrombophilia and hyperhomocysteinaemia using a comprehensive screen in patients with peripheral vascular disease. METHODS: A total of 150 patients with peripheral vascular disease (with an ankle brachial pressure index of less than 0.8) underwent thrombophilia screening (protein C and protein S, antithrombin, lupus anticoagulant, activated protein C resistance and factor V Leiden and prothrombin mutations). Fasting homocysteine assays were also performed. RESULTS: A thrombophilia defect was found in 41 patients (27.3 per cent). The commonest was protein S deficiency, found in 17 patients (11.3 per cent). Others included factor V Leiden mutation, found in 10 (6.7 per cent) and protein C deficiency, found in six (4.0 per cent). Lupus anticoagulant and prothrombin mutation were both found in six (4.0 per cent). One patient had an antithrombin deficiency. Only the presence of critical ischaemia was associated with a positive thrombophilia screen on single variable analysis (P = 0.03). Hyperhomocysteinaemia was present in over a third of the study group (37.3 per cent): 45 defined as moderate and 11 as intermediate. CONCLUSION: A quarter of patients with peripheral vascular disease had evidence of thrombophilia, and a third had hyperhomocysteinaemia.

Aged↗
PubMed2004

Prevalence and risk of thrombophilia defects in vascular patients.

This paper reviews the available data on the prevalence of thrombophilia defects in patients with peripheral vascular disease (PVD) and attempts to delineate the risk of failure of vascular intervention in these patients. The prevalence of thrombophilia in stable claudicants is 25% and increases to 40% in those requiring revascularisation, compared to only 11% in the control group. The overall prevalence of thrombophilia defects in patients with premature atherosclerosis appears to be between 15 and 30%. The prevalence in the typical cohort of patients with PVD appears to be similar. All these studies have recruited patients with symptoms significant enough to warrant intervention. The overall prevalence of thrombophilia calculated from these trials, therefore, may not be truly indicative of the general vascular population who may not even present primary or secondary healthcare. The risk of thrombotic occlusion following arterial revascularisation in patients with an identified thrombophilia defect appears to be almost three times that of patients with no evidence of a thrombophilia defect. The best management of these patients has not been determined and needs to be evaluated by prospective randomized trials.

Adult↗
PubMed2003

A clinical approach to the management of a patient with suspected renovascular disease who presents with leg ischemia.

Atherosclerotic renal artery stenosis (ARAS) may cause hypertension, progressive renal failure, and recurrent pulmonary edema. It typically occurs in high risk patients with coexistent vascular disease elsewhere. Most patients with ARAS are likely to die from coronary heart disease or stroke before end-stage renal failure occurs. Recent controlled trials have shown that most patients undergoing angioplasty to treat renovascular hypertension still need antihypertensive agents 6 or 12 months after the procedure. Nevertheless, the number of antihypertensive agents required to control blood pressure adequately is lower following angioplasty than for medication alone. Trials assessing the value of revascularization for preserving renal function or preventing clinical events are only in the early recruitment phase. Revascularization should be undertaken in patients with ARAS and resistant hypertension or heart failure, and probably in those with rapidly deteriorating renal function or with an increase in plasma creatinine levels during angiotensin-converting enzyme inhibition. With or without revascularization, medical therapy using antihypertensive, hypolipidemic and antiplatelet agents is necessary in almost all cases.

Humans↗
PubMed2001

Thromboelastography: a reliable test?

The thromboelastograph (TEG), a measure of global haemostasis, is routinely used during cardiac and hepatic surgery to optimize blood product selection and usage. It has recently been suggested that it may also be a useful tool to screen patients with hypercoagulable states. Limited published data on performance characteristics has led to speculation regarding its consistency and, therefore, validity of the results. This study was designed to assess the effect of stability of blood samples prior to testing, repeated sampling, intra- and inter-assay variability using the native, celite, tissue factor (TF) and Reopro-modified TEG. Analysis of native and celite samples after storage over 90 min showed a period of instability up to 30 min. Thereafter, all parameters between 30 and 90 min were stable [P = not significant (NS)]. When the same sample was repeatedly assayed, both native and celite TEG parameters showed a significant change towards hypercoagulability (P < 0.01), whereas the TF and Reopro-modified TEG showed no change. Intra- and inter-assay variability on samples tested after 30 min showed excellent reproducibility for all parameters (P = NS). The data suggest that the TEG is a useful tool in haemostasis but requires a formal standard operating procedure to be adopted that takes into account the initial period of sample instability.

Blood Specimen Collection↗
PubMed2000

A clinical approach to the management of the patient with coronary (Co) and/or carotid (Ca) artery disease who presents with leg ischaemia (Lis).

The purpose of this document is to provide the clinician with easy-to-use guidelines when faced with a patient with severe ischaemia in the limbs requiring interventional treatment; the CoCaLis document does not focus on the management of the lower limb ischaemia, but rather on the best possible approach to the associated coronary and/or carotid artery disease. The first part of the text deals with the epidemiological aspects of this condition followed by a description of, and proposals for, the management of risk factors. The next part deals with the approach to the coronary circulation and the carotid territory. In each part attention is mainly given to the practical aspects in terms of both diagnosis and treatment; for each of these steps the costs involved are considered and attention given to balancing the clinical decisions against the costs. The recommendations given are 'evidence based' when such evidence exists and, if not, the proposals are based on the consensus of the members of the group. In many instances it was apparent that the necessary information is not available in the literature. The authors hope that the CoCaLis document may not only improve the management of the vascular patient but also stimulate further research in this difficult clinical condition which carries a significantly increased risk for the patient.

Angioplasty, Balloon, Coronary↗
PubMed1999

Vascular surgical society of great britain and ireland: review of out-of-hours vascular procedures in a tertiary vascular unit

BACKGROUND: The aim of this study was to review out-of-hours vascular procedures in a tertiary vascular unit. METHODS: The vascular emergencies that presented outside normal working hours (17. 00 to 08.00 hours) in a vascular unit between January and June 1998 were reviewed. Only cases considered to be life or limb threatening and requiring urgent surgical or radiological intervention were assessed. RESULTS: The Table shows that a significant number of vascular emergencies was performed out of hours in one unit. This was, in part, due to an increase in the number of tertiary referrals, which represented 57 per cent of all emergency procedures. Reasons for the tertiary referrals were: no consultant vascular surgeon on call (33 per cent), no consultant interventional radiologist on call (26 per cent), lack of intensive care beds (30 per cent) and complex procedure (11 per cent). The overall mortality rate of patients referred in this period was 15 per cent. The unit has three consultant vascular surgeons, two consultant interventional radio- logists and one vascular specialist registrar. CONCLUSION: The significant increase in out-of-hours vascular emergencies, both surgical and radiological, has placed an enormous demand on senior members of the team. In addition, it has had a significant impact on the unit's elective admissions and waiting lists, in particular those for routine general surgery. To support the growth in complex emergency referrals, senior vascular fellows in both vascular surgery and radiology have been appointed and proposals are underway to restructure local vascular services.

Journal Article↗
PubMed1999

Intermittent claudication: a condition with underrated risks.

Intermittent claudication (IC) is a symptom of peripheral arterial occlusive disease (PAOD); it is subjective and therefore difficult to measure reliably. Both the WHO/Rose Questionnaire and the Edinburgh Questionnaire have been used widely, but they have a low sensitivity and therefore underestimate the true prevalence of IC. The addition of a clinical examination does not necessarily eliminate errors found on questionnaires alone. The single most important part of the physical examination to confirm a diagnosis of IC is the palpation of the patient's peripheral pulses, which alone appears to be more sensitive, but less specific, than the questionnaires. The most useful noninvasive test is the ankle-brachial pressure index (ABPI), and it has been suggested that a resting ABPI of 0.9 is up to 95% sensitive in detecting angiogram-positive disease, and almost 100% specific in identifying apparently healthy individuals. An ABPI of 0.9 or less is believed to be associated with 50% or greater vessel stenosis. The incidence of IC varies depending on the methodology used to define it, but there is a general pattern of a gradual increase in incidence up to the age of at least 70 years. For a chronic disease, the prevalence is a more relevant indicator of how common it is. The prevalence of IC is 3% to 6% in men aged 60 years and increases with age. The prevalence of asymptomatic PAOD may be as high as 20% in the adult population, using noninvasive testing. This is important because, as will be seen in later articles, PAOD, whether symptomatic or asymptomatic, is a serious risk factor for cardiovascular morbidity and mortality.

Adult↗
PubMed1999

Predictors of early disease in the lower limbs.

Increasing age and male gender are unavoidable risk factors for peripheral arterial occlusive disease (PAOD). A number of studies have looked at classical risk factors for atherosclerosis, such as diabetes, hypertension, lipid abnormalities, and smoking, as well as some more recently identified associations, such as plasma fibrinogen levels, impaired glucose tolerance, and hyperhomocysteinemia. However, most "risk factors" are really associations. A causal relationship may only reasonably be firmly established if a prospective controlled study shows that removing the risk factor significantly alters the course of the disease, as with smoking. Smoking is probably the strongest risk factor for intermittent claudication (IC), but hyperhomocysteinemia also appears to be strongly associated with the development of PAOD. Moderate alcohol intake and regular physical exercise appear to have a protective effect. A genetic risk factor is suggested but not as yet confirmed. The magnitude of the association varies from odds ratios of 2 to 3 for smoking and diabetes. There is insufficient evidence for hyperhomocysteinemia, but the effect may be even greater. The association with hypertension and lipid abnormalities is surprisingly inconclusive.

Adult↗
PubMed1999

Lower-extremity arteriosclerosis as a reflection of a systemic process: implications for concomitant coronary and carotid disease.

Peripheral arterial occlusive disease (PAOD), coronary artery disease (CAD), and cerebrovascular disease (CVD) are all manifestations of atherosclerosis or atherothrombosis, and therefore it is not surprising that the three conditions commonly occur together. Knowledge of the magnitude of co-existing cardiovascular disease and its prognosis is essential for the physician treating IC so that he can treat the local disease in its systemic context. The prevalence of CAD in patients with IC is 40% to 60%, although this may be asymptomatic and increases with the severity of the PAOD. Not surprisingly, the converse is also true; among individuals with CAD, the prevalence of PAOD is higher than in non-CAD individuals. The link between PAOD and CVD seems to be weaker than that with CAD, but again up to 60% of claudicants have some evidence of CVD. The prevalence of patients with CVD increases as the ABPI decreases. The evidence available from all of the relevant studies suggests that approximately 60% of patients with PAOD will have significant disease in the cardiac or cerebral circulation, and approximately 40% of patients with coronary disease or significant cerebral circulatory disease also will have PAOD.

Adult↗
PubMed1999

The natural history of claudication: risk to life and limb.

Although a patient with intermittent claudication (IC) will fear progression to severe disease and amputation, this is a relatively rare outcome of claudication, with only 1% to 3% of claudicants ever requiring major amputation over a 5-year period. Indeed, in one study, 50% of claudicants became symptom free during 5 years' follow-up. All the new evidence over the last 40 years has not altered the impression that only about one fourth of patients with IC will ever significantly deteriorate, and that deterioration is most frequent during the first year after diagnosis (6 to 9%) compared with 2% to 3% per annum thereafter. Smoking is the most important risk factor for the progression of local disease in the legs, with an amputation rate 11 times greater in smokers than nonsmokers. Diabetes, male gender, and hypertension are also important risk factors for progression. Because cerebrovascular disease (CVD), coronary artery disease (CAD), and peripheral arterial occlusive disease (PAOD) coexist, PAOD and IC should be regarded as a marker for increased risk from fatal and nonfatal cardiovascular event, and 2% to 4% of claudicants have a nonfatal cardiovascular event every year. The risk is higher in the first year after developing IC than in a long-standing stable claudicant, and the average claudicant is more likely to have a nonfatal myocardial infarction (MI) or stroke in the next year that of ever requiring a major amputation for his leg ischemia. The mortality in claudicants is 30% at 5 years, 50% at 10 years, and 70% at 15 years, without any clear decrease in these figures over the last 30 to 40 years. The mortality of claudicants is approximately two and a half times that of an age-matched general population.

Adult↗
PubMed1999

Predicting which patients will develop chronic critical leg ischemia.

Although numerically far less than claudicants, patients with critical leg ischemia (CLI) demand a disproportionately large commitment both in medical effort and economically and represent the major workload for vascular surgical units. The incidence and prevalence of CLI is approximately 500 to 1,000/million/year. The risk factors for the development of CLI are largely the same as those for the progression of local disease in IC, the most important, apart from age, being smoking and diabetes. Major amputation is more common amongst claudicants who are heavy smokers and who continue to smoke, and although stopping smoking slows down the vascular changes and reduces the likelihood of symptomatic progression, it does not reduce the risk of major amputation over the following 2 to 3 years. Diabetic PAOD patients are about 10 times more likely to come to amputation than nondiabetic PAOD patients, and the prevalence of gangrene is 20 to 30 times higher in individuals with diabetes and PAOD compared with nondiabetics with PAOD. There is some evidence that most of these effects of risk factors are additive.

Age Factors↗
PubMed1999

The fate of patients with critical leg ischemia.

In some highly specialized and aggressive units, 90% of patients with critical leg ischemia (CLI) will undergo some form of surgical or endovascular procedure; however, in most, the figure is nearer 50 to 60%. The primary amputation rate varies from around 10% to 40%. The mortality rate in these patients with standard therapy is around 20% at 1 year and between 40% and 70% at 5 years. Virtually all (95%) patients who present with ischemic gangrene, and 80% of those presenting with rest pain, are dead within 10 years. There appears to be a decline in overall major amputation rates associated with a corresponding increase in revascularizations. However, although technical advances may have resulted in a steadying or even decrease in amputations, comparisons of total amputations over a longer period suggest an increase, presumably attributable to an aging population. Some forward projections predict that major amputations will be doubled in the next 30 years.

Aged↗
PubMed1999

Acute limb ischemia.

Although there is little information on the incidence of acute limb ischemia (ALI) in the general population, it is estimated to be 14 per 100,000 and to compose 10% to 16% of the vascular workload. Also, as surgical intervention has become an option for ALI, the numbers actually referred appear to be increasing. The two main causes of ALI are either an embolism or a thrombosis, and differentiation based on history and clinical examination alone may be clinically impossible in 10% to 15% of cases. However, with the advent of thrombolysis, the distinction between emboli and thrombotic occlusions has become less important from the point of view of management. The natural history of ALI has remained largely unchanged despite the advent of the Fogarty catheter and thrombolysis. Patients presenting with ALI continue to have a particularly severe short-term outlook both in terms of loss of the leg and mortality, with 30-day amputation rates of between 10% and 30% and a mortality rate of around 15%. A patient with an embolic cause for an ischemic leg is at a higher risk of death because of the associated underlying cardiac disease, whereas patients with a thrombotic cause are more likely to lose a limb. The fact that overall mortality rates after intervention for acute ischemia have not improved dramatically over the past 20 years no doubt reflects the severity of the underlying diseases in these high-risk patients.

Acute Disease↗
PubMed1999

Major amputations: clinical patterns and predictors.

The major amputation rate is approximately 200 to 500/million/yr and occurs in patients presenting with an acute onset of critical leg ischemia (CLI) rather than in patients who steadily progress through increasingly severe claudication to rest pain and ulcers. Diabetics, who form only 2% to 5% of the population, form 40% to 45% of all amputees. Although it is widely believed that a below-knee (BK) to above-knee (AK) amputation ratio of 2.5 is the minimum acceptable for units providing a lower limb amputation service, the ratio is in fact usually very much below the recommended figure. The data suggest that primary healing of BK amputations ranges from 30% to 92% and the reamputation rate from 4% to 30%. If a popliteal pulse is palpable, then there is only a 10% failure rate, and bleeding during the operation does not seem to predict healing. Of the 30% of BK amputees whose wounds do not heal primarily, about half will need a higher major amputation, but once a BK major amputation has healed, only 4% of such patients ever need a higher amputation. A total of 90% of AK major amputations heal, 70% primarily. Two to three times as many BK amputees achieve full mobility than AK amputees, and there has not been any dramatic change in 20 years. The fate of the amputee 2 years after a successful BK amputation will be that 15% will have been converted to an AK amputation, another 15% will have had a contralateral major amputation, and 30% will be dead.

Acute Disease↗
PubMed1997

Comparison of graded versus constant treadmill test protocols for quantifying intermittent claudication.

The standard method for quantifying the symptoms of intermittent claudication is by using treadmill walking distance. It has recently been suggested that a graded exercise test is much more reproducible than a constant load exercise test. Graded protocols have also been claimed to abolish the placebo effect that has been reported with the constant load test. The reproducibility of absolute claudication distance (ACD) and initial claudication distance (ICD) using a constant load was compared to the graded load treadmill protocol. Fourteen patients (mean age 66 years) with varying severity of stable intermittent claudication were tested using a constant load (3.2 km/h, 10% gradient) and a graded load (3.2 km/h, 0% gradient increasing by 3.5% every 3 min). Patients were tested twice using each protocol in a random sequence, with a minimum 2 day interval between visits. Intra-class correlation coefficient (R) with a constant load protocol for ICD and ACD was R = 0.68, R = 0.93, respectively. With a graded protocol R = 0.84 for ICD and R = 0.98 for ACD. Relative coefficient of repeatability for ICD and ACD during constant load tests were 1.47 and 1.90 respectively and with a graded load test were 1.69 and 1.52 respectively. It was concluded that the graded load test was more reproducible than the constant load test but only by a small margin, whilst ACD was much more reproducible than ICD using either protocol.

Aged↗
PubMed1995

Intrahepatic biliary cholesterol and phospholipid transport in humans: effect of obesity and cholesterol cholelithiasis.

The mode of transport of biliary lipids within the hepatocyte and the role of the bile canalicular membrane (BCM) in biliary lipid secretion are not well understood. We hypothesized that biliary cholesterol and phospholipid are co-transported across the hepatocyte in vesicular form from the endoplasmic reticulum to the bile across the BCM. We obtained wedge liver biopsies and fasting gallbladder bile from 15 cholesterol gallstone patients and 10 control subjects. BCM, basolateral membrane (BLM), and many microsomal vesicular fractions were isolated by centrifugation. One of the vesicular fractions (V3) was enriched in both the microsomal and the BCM marker enzymes and had a high phosphatidylcholine proportion in its phospholipid with a fatty acid pattern similar to biliary phosphatidylcholine. Moreover, its cholesterol content was increased in the obese cholesterol gallstone subjects, who had an increase in cholesterol synthesis, as indicated by the increased activity of the HMG-CoA reductase. The cholesterol content correlated with HMG-CoA reductase activity. A direct correlation was found between cholesterol/phospholipid ratio in V3, BCM, and in bile but not in the BLM. These data are in agreement with the assumption that this vesicular fraction is involved in the transport of cholesterol and phospholipid from the endoplasmic reticulum to the site of secretion in the BCM, and thence to bile, and that this transport is enhanced in obese gallstone patients.

Bile Canaliculi↗
PubMed1994

Prospective study of 713 below-knee amputations for ischaemia and the effect of a prostacyclin analogue on healing. Hawaii Study Group.

In 51 hospitals in six European countries 713 patients requiring below-knee amputation for ischaemic disease were studied prospectively. The patients were allocated randomly to receive standard postoperative treatment or standard treatment plus intravenous infusion of the prostacyclin analogue iloprost for 6 h per day over 14-21 days. Healing of the amputation stump and the need for reamputation at a higher level were similar in the two groups. Overall at 3 months 59 per cent of stumps had healed, 19 per cent of patients had required reamputation at a higher level, 11 per cent had died and the remaining 11 per cent remained with unhealed stumps. Preoperative characteristics were analysed as possible risk factors or markers for primary healing, reamputation and death. Previous arterial reopening procedures (surgical or radiological) almost doubled the chances of primary stump healing (P < 0.05). The surgeon's assessment of the likelihood of healing was wrong in 21 per cent of cases in which the operating surgeon thought that healing would probably occur and in 52 per cent of those in which it was thought healing was improbable.

Adult↗