Remodelling of vascular (surgical) services in the UK.

The last few years have seen major changes in the delivery of vascular services in the UK. An increasingly elderly population with greater expectations from their medical services has challenged established methods. It also became apparent that outcomes for low volume, high risk index vascular interventions such as abdominal aortic aneurysm repair were poor in the UK compared to the rest of Europe. Other ongoing challenges were the introduction of a national aortic aneurysm screening programme and the development of vascular surgery as a separate speciality. This article details the approach taken to modernise vascular services in the UK, using a quality framework agreed by vascular specialists, which drove the structural change to move vascular interventions into fewer, higher volume centres. The introduction of modern networks is designed to maintain services in surrounding hospitals without on site vascular inpatient services. The initial effects of this service remodelling are positive, with elective aortic aneurysm mortality rates falling nationally from 7.5 to 2.4 per cent.

Skeletal muscle adaptation in response to supervised exercise training for intermittent claudication.

OBJECTIVES: There is evidence that the improvement following supervised exercise for claudication results from skeletal muscle adaptation. The myosin heavy chain (MHC) determines muscle fibre type and therefore efficiency. Immunohistochemical analysis has failed to take account of hybrid MHC expression within myofibres. This study sought evidence of differential MHC protein expression following supervised exercise for claudication. DESIGN: 38 claudicants were recruited. Subjects undertook a three-month supervised exercise programme. Controls were patients awaiting angioplasty for claudication. MATERIALS AND METHODS: Subjects underwent paired gastrocnemius biopsy. Relative expression of MHC proteins was determined by SDS-PAGE electrophoresis. Non-parametric data is presented as median with the inter-quartile range and parametric as the mean ± standard deviation. RESULTS: Upon completion of the exercise programme there was a 94% increase (124 (106-145) to 241 (193-265) metres, p = 0.002) in maximum walking distance, which was not evident in the control group. An 11.1% (p = 0.02) increase in MHC I expression was observed in the exercise but not the control group (34.3% ± 6.8 to 45.4% ± 4.4). There was a positive correlation between the change in MHC I expression and the improvement in claudication distance (r = 0.69, p < 0.05). CONCLUSIONS: Supervised exercise training for claudication results in an increase in the proportion of MHC type I expression within the symptomatic gastrocnemius muscle.

Exercise training for claudication.

Exercise advice is a well established component of the conservative management of intermittent claudication. Supervised programmes of exercise remain relatively uncommon and are provided mainly in secondary care. This review outlines the evidence for the effectiveness of different exercise regimens and the relative benefits of exercise therapy, where comparisons have been made with medical therapy, angioplasty and surgery.

Spontaneous resolution of carotid stenosis--a case for routine preoperative duplex ultrasound.

Spontaneous resolution of carotid stenosis has not been previously reported in the context of preoperative duplex ultrasound scanning, although it has been described as a recognizable phenomenon in the past. We report a case in whom significant carotid stenosis was noted at the time of listing for surgery on both duplex ultrasound and MRA. On preoperative imaging there was resolution of the lesion and surgery was avoided. This case emphasises that spontaneous resolution of carotid stenosis can occur and that preoperative duplex is useful as a prelude to surgery and can prevent unwarranted intervention.

The impact of shortened training times on the discipline of vascular surgery in the United Kingdom.

Political initiatives and European health and safety working time regulations have combined to reduce the time available for surgical training in the United Kingdom in the future by a third. For the safety of patient care, surgeons must evolve strategies to cope with these reduced training times so that they preserve the current high level of competence exhibited by UK trainees when they attain the right to independent surgical practice recognized by appointment as a Consultant Surgeon. Such strategies include a focus on dedicated training time, the use of simulators, and a move towards progression based on satisfactory completion of a defined curriculum and competency assessment rather than the amount of time served. With insufficient time to train in every aspect of general surgery, a move towards fragmentation into its sub-specialty components seems unavoidable. Such a move offers an opportunity to re-evaluate conventional surgical training and to consider the evolution of a system-specific vascular specialist with patient-focused expertise in vascular surgery, endovascular radiology, and vascular medicine.

The effect of acute normovolaemic haemodilution on the inflammatory response and clinical outcome in abdominal aortic aneurysm repair--results of a pilot trial.

OBJECTIVES: To determine the effect of acute normovolaemic haemodilution (ANH) on the inflammatory response and clinical outcome in elective open abdominal aortic aneurysm (AAA) repair. DESIGN: Randomised controlled clinical trial. METHODS: Thirty-six patients were randomised to undergo ANH or act as controls. Cell salvage was permitted in both groups. Heterologous blood was transfused according to pre-determined triggers. Outcome measures were markers of the systemic inflammatory response in serum and urine observed at multiple time points, and clinical recovery. RESULTS: Median 890 (range 670-1620) ml of blood was removed at ANH in 16 patients. There were no differences in peri-operative changes in neutrophil count ( P = 0.13), serum C-reactive protein ( P = 0.38), interleukin-6 ( P = 0.50), total antioxidant capacity ( P = 0.73), urinary secretion of albumin ( P = 0.97) or retinol binding protein ( P = 0.41). There were no differences in the mortality and morbidity rates, systemic inflammatory response syndrome, ITU or hospital stay. CONCLUSIONS: ANH, when used in combination with cell salvage, made no impact on systemic inflammatory response and clinical outcome when compared to cell salvage alone after AAA repair. ANH cannot be recommended for routine use in patients undergoing abdominal aortic aneurysm surgery when cell salvage is available.

Haemodilutional effect of standard fluid management limits the effectiveness of acute normovolaemic haemodilution in AAA surgery--results of a pilot trial.

OBJECTIVE: To evaluate the impact of standard fluid management on the effectiveness of ANH as a blood conservation method in elective open AAA repair. DESIGN: Prospective randomised controlled study. METHODS: Thirty-four patients undergoing elective AAA repair were randomised to have ANH (16) or act as controls (18). Intra-operative cell salvage was permitted in both groups. Haemoglobin (Hb) concentrations were determined at variable intervals peri-operatively. Blood loss and the use of heterologous blood were recorded. RESULTS: The pre- and post-operative Hb concentrations, surgical blood loss and the use of cell salvage were similar in both groups. Hb concentration (median, range) decreased significantly from pre-operative to aortic clamping (with blood loss <100 ml) in ANH patients from 8.8 (7.5-10.2) to 5.7 (4.2-6.6)mmol/l following ANH but also in controls from 8.6 (7.5-9.7) to 7.0 (4.5-9.0)mmol/l due to fluid infusion (P<0.01 for every comparison). Bank blood requirements were similar: median 2 units in ANH and 2.5 units in control patients (P=0.68). CONCLUSIONS: Large volumes of fluids infused during AAA repair already conserve blood by the mechanism of hypervolaemic haemodilution. When cell salvage is used with standard fluid management during AAA repair, additional ANH is ineffective in saving blood.

Reoperation for neurological complications following carotid endarterectomy.

BACKGROUND: There remains a dilemma whether or not to re-explore the carotid artery when a neurological complication occurs after carotid endarterectomy. This study reviewed the indications for, findings and clinical outcomes following re-exploration. METHODS: Patients who experienced transient or permanent neurological events following carotid endarterectomy were identified from a prospectively compiled computerized database. Case notes were retrieved to determine time to onset of symptoms, use of carotid artery imaging and details about patients who had surgical re-exploration, and outcomes. RESULTS: Some 780 consecutive carotid endarterectomies were performed over 16 years, with an incidence of major stroke or death of 2.3 per cent (18 patients). Fifty-one patients experienced transient or permanent neurological events following surgery, 25 of whom underwent re-exploration. The findings included carotid thrombosis (ten patients), flap or other technical cause (three), haematoma (two) and no abnormality (ten). The neurological outcome after 30 days was similar, whether or not the carotid artery was re-explored. CONCLUSION: Carotid artery re-exploration was undertaken in approximately half of the patients who developed neurological complications following carotid endarterectomy. Although the cause was identified and a secondary procedure was undertaken in 14 of 25 patients, there was no improvement in clinical outcome at 30 days compared with that of patients managed non-operatively.

Risk factor documentation in elective and emergency vascular surgical admissions.

OBJECTIVES: this study investigates current practice of risk factor documentation in a vascular unit and compares variations in risk factor assessment between elective and emergency admissions. METHODS: one hundred and forty-four patients who underwent vascular surgical intervention for atherosclerotic disease during the year 2000 were retrospectively identified from computerised database. Case note review collated demographic details, data on risk factor assessment and the nature of surgery. Data were analysed using SPSS statistical software. RESULTS: the male to female ratio was 2.3:1 with a median (range) age of 73 (31-95) years. For 55 (38%) emergency admissions the following risk factors were not documented; ischaemic heart disease (8), diabetes mellitus (10), hypertension (10), smoking habit (13) and antiplatelet therapy (18). For 89 (62%) elective admissions the following risk factors were not documented; ischaemic heart disease (11), diabetes mellitus (9), hypertension (4), smoking habit (5) and antiplatelet therapy (19). Sixty-six (72.5%) routine admissions and 11 (20.8%) emergency admissions had estimations of serum cholesterol documented (chi(2) p < 0.001). There were no statistically significant differences in the documentation of other risk factors between the 2 groups. CONCLUSION: risk factors are not documented consistently for emergency vascular surgical admissions. Staff education should aim to improve risk factor assessment for elective and emergency admissions to reduce cardiovascular events and possibly improve surgical outcome in patients with atherosclerotic disease.

Pre-operative hand-held Doppler run-off score can be used to stratify risk prior to infra-inguinal bypass surgery.

OBJECTIVES: to investigate the relationship between calf vessel run-off assessed by hand-held Doppler, graft patency and patient survival following infra-inguinal graft surgery. DESIGN: prospective cohort study of 258 consecutive patients undergoing infra-inguinal bypass grafts in one centre between 1995-99. MATERIALS AND METHODS: ankle Doppler auditory waveform characteristics were documented for patients considered for infra-inguinal bypass grafting. Doppler signals from the anterior tibial, posterior tibial and dorsalis pedis arteries were scored triphasic/biphasic (2), monophasic (1) or absent (0). A total Doppler run off score (0-6) was calculated. Following surgery graft surveillance was undertaken using duplex ultrasound at 6, 12, 26 and 52 weeks. Graft and patient survival were analysed using Cox regression analysis. RESULTS: overall primary assisted graft patency at one year was 80%. With an increasing Doppler score from 0 to 6, primary assisted graft patency steadily rose from 50% to 100% (p = 0.0002), accompanied by a steady fall in patient mortality from 50% to 5% (p = 0.0003).

A randomised, double blind, placebo-controlled study to determine the efficacy of immune modulation therapy in the treatment of patients suffering from peripheral arterial occlusive disease with intermittent claudication.

OBJECTIVES: this study examined the effect of immune modulation therapy (IMT) on claudication distances. MATERIALS AND METHODS: a double-blind placebo controlled trial was performed on patients with disabling intermittent claudication with randomisation stratified for short and long distance IC. For IMT, following exposure to UV light, oxidisation and 42.5 degrees C, 10 ml of citrated autologous blood was administered by intra-muscular injection. One course consisted of 6 injections in 3-weeks followed by 3-weeks rest. Patients received 2, 3 or 4 courses depending on response. The primary end-point was the number of responders (>50% increase in initial claudication distance (ICD)) in each group. Secondary end-points included percentage changes in ICD and change in quality of life. RESULTS: at week 24, there were more responders in the IMT group (20/31, 65%) compared to placebo (16/39, 41%) (p=0.06). In the subgroup of short distance claudicants this difference reached significance (IMT 17/26, 65%) (Placebo 12/33, 36%) (p=0.04). The median increase in ICD was significantly greater in the IMT group (81%) compared to placebo (44%, p=0.04). These results were supported by quality of life measurements. CONCLUSIONS; IMT is a safe and apparently effective treatment for patients with short distance claudication.

The systemic effects of intermittent claudication are reversed by angioplasty.

INTRODUCTION: exercise in patients with intermittent claudication causes systemic effects, the consequences of which are unknown. This study investigates whether successful PTA reverses the systemic effects. PATIENTS AND METHODS: ten patients with IC were recruited prior to PTA. Having emptied their bladders and rested for 1 h, pre-exercise blood and urine samples were collected. Patients underwent treadmill exercise to maximum walking time and blood samples were collected at 10, 20 and 30 min. A second urine sample was collected at 60 min. Total antioxidant capacity (TAC) and von Willebrands Factor (vWF) were measured in blood and albumin/creatinine ratio (ACR) and retinol binding protein/creatinine ratio (RBP/Cr) in urine. Patients were recalled 2 weeks after successful angioplasty and the protocol repeated. Following PTA patients walked for a maximum of 5 min. RESULTS: there was no significant change in vWF. Exercise in claudicants induced a significant increase in median ACR (pre/post exercise=0.85 p =0.03) and in median RBP/Cr (pre/post exercise=1.8 p =0.04). These changes were no longer evident after successful PTA. TAC was significantly different before and after angioplasty at all time intervals. CONCLUSION: successful PTA reverses glomerular effects of exercise in claudicants. Future work should investigate the use of PTA in conjunction with exercise in the treatment of peripheral vascular disease.

The effect of acute normovolaemic haemodilution on blood transfusion requirements in abdominal aortic aneurysm repair.

OBJECTIVE: to evaluate the impact of acute normovolaemic haemodilution (ANH) on the blood transfusion requirements in elective abdominal aortic aneurysm (AAA) repair in a single vascular unit. METHODS: thirty-two patients underwent ANH during elective AAA repair between 1992 and 1997. The operation was performed by the same surgeon/anaesthetist team in 75% of cases. Their demographic details, type of aneurysm (infra-renal or supra-renal), preoperative blood cross match, use of intra-operative red cell salvage, blood loss, peri-operative bank blood requirements, pre-op and on-discharge haemoglobin levels and post-operative outcome were recorded. The results were compared to a group of 40 randomly selected patients (to represent the unit average) who underwent elective AAA repair by variable surgeon/anaesthetist teams without ANH in the same time period. RESULTS: there were more supra-renal AAA repairs in the ANH group (8/32) than in the non-ANH group (0/40, p<0.01). ANH patients required significantly less blood transfusion peri-operatively (median 2 units) than the non-ANH patients (median 3 units, p=0.02). There were no other significant differences between the variables measured. CONCLUSION: these results suggest that a dedicated team can achieve significant reductions in the use of heterologous blood transfusion compared to the vascular unit average experience by the effective use of ANH.

The association of platelet-derived growth factor receptor expression, plaque morphology and histological features with symptoms in carotid atherosclerosis.

Platelet-derived growth factor may influence smooth muscle cell migration and proliferation and, therefore, carotid plaque composition and stenosis. Platelet-derived growth factor receptor expression and histological features were compared in carotid plaques from symptomatic and asymptomatic patients. Immunocytochemistry and histology determined platelet-derived growth factor-alpha and -beta receptor expression, white blood cell infiltration, smooth muscle cell, elastin, cholesterol, collagen and intraplaque haemorrhage in carotid artery plaques removed at surgery or the post-mortem. Plaques with > 70% stenosis from asymptomatic (n = 10) and symptomatic patients (n = 27) had higher expression of platelet-derived growth factor and beta receptors and higher scores for macrophages and intraplaque haemorrhage than plaques with < 70% stenosis from asymptomatic patients (n = 33). Plaques with > 70% stenosis from symptomatic patients had significantly lower alpha receptor expression than plaques with > 70% stenosis from asymptomatic patients. The reduction of alpha receptor expression, which may inhibit smooth muscle cell migration, suggests that differential expression of platelet-derived growth factor receptor subunits in plaques may be related to symptoms.

Vascular surgical intervention for complications of cardiovascular radiology: 13 years' experience in a single centre.

This study investigates incidence and outcome of iatrogenic vascular complications needing surgery in a single vascular unit serving interventional vascular radiology and interventional cardiology. Evolution of diagnostic and interventional cardiovascular radiology, along with the introduction of non-surgical therapies for such complications, may have influenced the number of vascular complications requiring emergency surgery. Vascular surgical data were collected from information prospectively entered on computerised database and case note review. Radiology data were collated from prospective entries in logbooks and computerised database. In all 24,033 cardiovascular radiological procedures were performed between 1984 and 1996 (61% cardiac), numbers increasing annually. During this period, 62 patients (40 peripheral; 22 cardiac) required emergency surgical intervention after radiological procedures. Mean age was 61.9 years (range 1-92 years), male to female ratio was 1:1. The absolute number of cases requiring surgical intervention peaked in 1989, subsequently reducing annually. Sites of vascular injury included common femoral artery (40), brachial artery (6), iliac artery (6), popliteal artery (5), other (5). A total of 87 vascular surgical operations was performed (range 1-6 operations per patient). Interventions included thrombectomy/embolectomy (29), bypass grafting (16), direct repair (27). Seven major amputations were performed (two bilateral). Mortality after surgery was 9.7%. Mean inpatient hospital stay was 11.3 days (range 0-75 days). A Poisson regression model indicates a 5% reduction in risk for each successive year of observation; however, this did not reach statistical significance (P = 0.16, 95% CI 12% decreased risk to 2% increased risk). The risk of surgical intervention after diagnostic or interventional cardiovascular radiology is diminishing but still requires vigilance. Necessity for surgical intervention is associated with a high risk of morbidity and mortality.