Pm Lamont

Treatment of intermittent claudication: The impact on quality of life

OBJECTIVES To measure changes in claudicants quality of life after surgery, angioplasty or unsupervised exercise. To explore the relationship between clinical indicators of limb perfusion and patients perception of health change. DESIGN Prospective study. SETTING University Hospital vascular outpatients. MATERIALS AND METHODS 202 claudicants referred for Duplex of lower limb arterial disease over a 12 month period. The short form 36 questionnaire was used to determine quality of life. Ankle pressures and walking distances were determined. MAIN RESULTS The SF-36 was completed by 186 patients (92%) before and after treatment (34 operative patients, 74 angioplasty and 78 treated by exercise alone). Baseline quality of life was worse in surgical patients. Unsupervised exercise produced minimal changes in quality of life. Angioplasty and operation produced similar, significant improvements in physical functioning and pain. Changes in physical function or pain scores were unrelated to changes in ankle pressure. CONCLUSIONS Unsupervised exercise programs are unlikely to significantly improve patients quality of life. The benefits of surgery and angioplasty support a relaxation in the indications for investigation and treatment of claudicants. Patients with impaired perceived health should not be denied treatment on the basis of preintervention ankle pressure or walking distance alone.

Cognitive testing in patients undergoing carotid endarterectomy

OBJECTIVES To determine by literature review the effect of carotid endarterectomy (CEA) as a modulator of cognitive function in patients with carotid arterial disease. Derive recommendations for standardising cognitive testing of patients with carotid arterial disease. DESIGN AND METHODS The English language literature was interrogated using a CD-ROM driven medline search using carotid endarterectomy and cognitive function as keywords between 1986-1995. These subsets were scanned and papers of direct relevance or commonality were selected. Cited papers prior to 1986 from these references were then sought directly. RESULTS There are few controlled studies reporting on the effect of CEA. There is no consensus in the literature for the effect of CEA on cognition or which tests should be used. Studies reporting a benefit for CEA lack a control group and fail to eliminate the effect of practice. Reports suggesting cognitive impairment following CEA performed follow-up tests early. CONCLUSIONS There are many methodological problems with the study of cognitive function before and after carotid endarterectomy and wide disagreement in the interpretation of results. Further studies should contain control groups, use tests resistant to practice and be performed when the effects of surgery and anaesthesia are passed.

Activated protein C resistance, factor V Leiden and peripheral vascular disease

Activated protein C resistance caused by factor V Leiden is an important thrombophilia disorder which predisposes to venous thromboembolism. Some studies also suggest a role in the pathogenesis of arterial thrombosis and atherosclerosis. The authors have investigated the prevalence of activated protein C resistance and factor V Leiden in a series of 45 patients with peripheral vascular disease. Twelve patients were receiving warfarin. The activated protein C resistance ratios were significantly lower in the group of 33 non-warfarinized patients with peripheral vascular disease (median 2.82 (range 1.36-3.83)) compared with 33 age- and sex-matched controls (median 2.97 range 2.24-4.11); P<0.005; Wilcoxon rank sum). Eight patients (24%) had activated protein C resistance (ratio <2.2). The prevalence of factor V Leiden in patients with peripheral vascular disease was 17.8% (8/45). This is significantly increased compared with the local population and UK published frequency of 3.5% for this genotype. The presence of factor V Leiden did not affect the late outcome of arterial reconstructive surgery in terms of graft patency (P=0.5, Fishers Exact test).

Preferential use of vein for above-knee femoropopliteal grafts

OBJECTIVES Many centres preferentially use polytetrafluoroethylene (PTFE) for above-knee femoropopliteal bypass as surgery is simplified and patency rates are comparable to vein, which is preserved for subsequent revisions or for distal disease progression. In this Unit, vein remains first choice graft material. The aim of this study was to audit our results with respect to above-knee bypass to establish the demand for vein for secondary reconstruction and to document the ultimate fate of the limb. PATIENTS Between 1983 and 1992, 112 above-knee reconstructions were performed on 109 patients (89 vein and 23 PTFE grafts). PTFE was used where vein was absent or inadequate. Life table analysis of primary graft patency, limb salvage and patient survival up to 36 months follow-up concurs with previously reported series. RESULTS Twenty-eight vein grafts (31%) and 11 PTFE grafts (48%) occluded during a median follow-up of 64 months (8-116 months). In only four cases was vein required for secondary procedures. The remainder were salvaged by thrombectomy and local procedures for technical problems. Amputation rates following graft occlusion were 12% in the vein group (20% of these being above-knee) as against 26% in the PTFE group (80% above knee). CONCLUSIONS The demand for vein for secondary procedures is low. Amputation rates when vein grafts do occlude are half those of PTFE and amputation level is significantly influenced by graft type. We advocate preferential use of vein in above-knee femoropopliteal bypass.

Vein graft stenosis: Incidence and intervention

OBJECTIVES The incidence of vein graft stenosis ranges from 5%-45%. Reported rates appear to be increasing as technological advances make detection easier. The aim of this study was to review our experiences with regard to the incidence of stenosis in infrainguinal bypass grafts and the outcome of intervention for salvage of failing grafts. DESIGN Retrospective review of graft surveillance records. SETTING Vascular Studies Unit, Bristol Royal Infirmary. METHODS A Duplex-based graft surveillance (GS) programme was used from January 1989 to June 1994 to study 275 primary graft procedures in 250 patients with lower limb ischaemia. Patients were scanned at 1 week, 6 weeks and 3, 6, 9 and 12 months postoperatively. RESULTS One year cumulative limb salvage, patient survival and primary, primary assisted and secondary patencies were 91%, 83%, 67%, 77% and 84% respectively. Duplex scanning detected 85 vein graft stenoses in 59 patients: an incidence of 21.5%. In addition, 64 potentially graft-threatening inflow (14) and outflow (50) problems were detected in the native vessels of 52 patients from clamp damage or progression of disease (POD). Of the 85 graft stenoses, 40 were treated by balloon angioplasty (PTA) and 20 by surgical intervention and 1 patients symptoms were treated by chemical sympathectomy. Twenty-four patients were not actively treated. Of the 64 grafts affected by POD, 20 were treated by PTA, 15 by surgery, one with anti-coagulation and 28 had no treatment. Comparing patients with non-treated and treated lesions, the respective 12 month cumulative patencies for patients with graft stenoses were 75% and 87.5% as against 86% and 83% for patients with POD (log rank test 0.1). CONCLUSIONS These results uphold the perceived benefits of a GS programme, although the evidence from the non-treated cases in this series reinforces a need for a large, prospective, randomised trial to confirm the case for GS.

Non-invasive aortoiliac assessment

OBJECTIVES To assess the accuracy of Duplex ultrasound in the assessment of aortoiliac disease. DESIGN Prospective, semi-blind study. SETTING Vascular laboratory and radiology departments, University Hospital. MATERIALS AND METHODS Ninety-two patients underwent assessment of the aortoiliac segment by femoral pulse palpation, Duplex ultrasound and biplanar arteriography. Of these 184 aortoiliac segments, 68 were also assessed by intraarterial pressure measurements and 80 by magnetic resonance angiography (MRA). MAIN RESULTS Femoral pulses were abnormal in all 32 occluded aortoiliac segments. Of 152 patent segments, femoral pulse palpation was misleading in 50 (33%). MRA detected all occlusions and had a sensitivity of 71% and specificity of 68% for stenoses, compared to arteriography. Colour flow Duplex misdiagnosed four occlusions as stenoses. Duplex had a sensitivity of 91% and specificity of 93% for stenoses when compared to arteriography. Two stenoses, detected by Duplex and confirmed by pressure gradients, were missed by arteriography. CONCLUSIONS Pressure measurements remain the gold standard for aortoiliac examination, arteriography providing only morphological information. The limitations of femoral pulse palpation should be appreciated. Although MRA was faster, Duplex examination proved slightly more sensitive to stenoses. At present, colour Duplex provides the best non-invasive assessment of aortoiliac disease and could prevent unnecessary arteriograms.

Exercise for intermittent claudication. Supervised programmes should be universally available.

Intermittent claudication is a common condition leading to significant functional impairment and enhanced risk of cardiovascular morbidity and mortality. However, despite the functional impairment caused by intermittent claudication, the natural history in the affected limb is fairly benign. Only about 25% of patients show symptomatic deterioration and only 2% eventually lose the affected limb.1 This epidemiological evidence has led most clinicians in both primary and hospital care to manage intermittent claudication conservatively, addressing cardiovascular risk factors2 and giving advice on exercise. This may well be appropriate but merely giving advice about exercise is unlikley to be the most effective treatment. Exercise as a treatment for intermittent claudication is not new, with improvements in walking described from as early as 1898. A recent Cochrane review of 10 randomised trials of exercise therapy estimated an overall improvement in walking distance of about 150%.3 The exercise component in all but one of these …

Hyperhomocysteinaemia is a risk factor for vein graft stenosis.

OBJECTIVES Many infrainguinal vein graft failures are due to progressive vein graft stenosis (VGS) from intimal hyperplasia. Systemic factors have been implicated in the aetiology of intimal hyperplasia. Hyperhomocysteinaemia (HHCA) is established as an independent risk factor for coronary and peripheral arterial disease. The objective of this study was to examine the influence of HHCA and other serological factors upon the development of VGS. STUDY DESIGN Thirty-eight patients who had undergone infrainguinal vein bypass were recruited to a case/control study from a graft surveillance program. Nineteen patients with documented VGS were matched against controls without stenosis for age, sex, length of time from surgery, diabetes, smoking history and preoperative symptom score. All patients were recalled for Duplex ultrasound scans, venesection and carbon monoxide estimation which were performed in a blinded fashion. RESULTS Statistical analysis of all parameters revealed that plasma homocysteine was significantly elevated in patients with VGS (p < 0.3, Wilcoxon rank sum). CONCLUSIONS These results suggest that HHCA is a previously unidentified risk factor for VGS. Patients with HHCA are susceptible to VGS and preoperative investigation would allow identification of patients at risk.

Carotid plaque morphology: a review.

The recent North American Symptomatic Carotid Endarterectomy Trial has answered fairly conclusively the questions concerning the optimal management of patients with symptoms who have a > 70% stenosis of the internal carotid artery. It has also had the effect of refocusing attention on carotid pathology. The main question still to be answered is whether surgical management is the optimum treatment for other groups of patients with carotid disease. From various studies done on the natural history of carotid plaques it is apparent that there are subgroups who may benefit from surgery, namely those who will progress to stroke if not treated. The problem comes in identifying these subgroups by the factors which cause them to progress. This paper aims to review the role that plaque morphology has in the development of symptoms and whether it should be included with degree of stenosis in assessing the risk of a carotid plaque. The non-invasive assessment of plaque morphology is also reviewed. The evidence from this review does not support the use of plaque morphology as a discriminating factor for carotid endarterectomy at present.

Local Versus Systemic Mechanisms Underlying Supervised Exercise Training for Intermittent Claudication

The mechanisms by which exercise training improves intermittent claudication remain unclear. In this article, the effects of local and systemic physiological factors on improved exercise tolerance after a supervised exercise program in claudicants are investigated. A total of 60 patients were randomized to 3 months of supervised exercise followed by 3 months of unsupervised exercise, or to exercise advice alone (control). Supervised exercise increased both pain-free and maximal walking distances. Heart rate during submaximal exercise and resting mean arterial pressure were lower after supervised exercise at 6 months. Serum lactate at maximum claudication increased significantly after 3 months in the supervised exercise group but this change had resolved by 6 months. Symptomatic improvement was accompanied by modest reductions in mean arterial pressure and submaximal heart rate on exercise. Increased serum lactate at maximum claudication subsequently declined despite continued improvement in walking distance, suggesting local adaptations to improve efficiency of muscle oxygen delivery and/or utilization.