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D J A Scott

Publications and source records attributed to D J A Scott.

13 recordsLinked to original sources
PubMed2003

An audit of out of hours interventional vascular radiology.

BACKGROUND: in 1996 the Royal College of Radiologists established a set of guidelines for out of hours radiology. Part of the recommendations determined that all units should regularly assess their own out of hours workload. In light of these guidelines we have audited our units interventional radiology activity. METHODS: this was a retrospective study looking at the number of emergency angiograms and procedures performed over a 1-year period. Patients were identified from a vascular radiology database and case notes reviewed. RESULTS: a total of 1902 patients had angiograms with 686 having further procedures. Of these, 1093 patients (57%) having 380 procedures (55%) were under the care of a consultant vascular surgeon. Of the vascular surgical patients only 17 patients (1.6%) were actually investigated out of hours (1700-0800 weekdays and at weekends). 5/17 (29%) patients received thrombolysis and 7/17 (41%) had either an angioplasty or stent. Despite being a major vascular unit only 2/17 (12%) were patients referred from outside the units own trust. Following diagnostic angiography, 13/17 (76%) of patients had an intervention performed within the first 24h. CONCLUSION: in a unit performing a large number of angiograms only a small number of patients require out of hours emergency angiography and interventional vascular procedures. Our impression is that this is the result of a flexible and responsive in hour's service. At the present time extra-hospital referrals do not appear to generate large amounts of out of hours work. This level of out of hours activity has implications in the provision of vascular radiological services in the future.

Adult↗
PubMed2002

How effective is acute normovolaemic haemodilution in femoro-distal bypass surgery?

BACKGROUND: Recent guidelines have emphasised the use of autologous blood in the surgical setting. The aim of this study was to analyse the efficacy and efficiency of acute normovolaemic haemodilution (ANH) as a blood conservation intervention in patients undergoing elective femoro-distal surgery for critical limb ischaemia. METHODS: Forty patients were studied prospectively. The volume of the blood collected was derived as follows: Blood volume removed = patient's blood volume (initial haematocrit - final haematocrit/average haematocrit) where final haematocrit is 30% and patient's blood volume is 70 and 65 ml/kg for a man and a woman, respectively. RESULTS: Twenty-five patients were suitable for ANH and 15 patients were excluded because of poor ventricular function, anaemia or renal disease. Nine of the 25 patients (44%) had <500ml of surgical blood loss and would have avoided homologous blood transfusion (HBT). Four of the patients lost >2000ml of blood and could not avoid HBT through ANH. Twelve patients had moderate blood loss (950-1400 ml), with eight of these patients requiring transfusion. Four patients avoided exposure to homologous blood. CONCLUSION: ANH is in evolution and as a single blood conservation intervention, contributes only modestly to blood conservation.

Aged↗
PubMed2002

Exercise training reduces the acute inflammatory response associated with claudication.

BACKGROUND: recent research has shown that episodes of claudication may be associated with a systemic inflammatory response that causes injury to the vascular endothelium. As claudicants are often directed to undertake regular walking exercises there has been a concern that this may accelerate endothelial injury. AIMS: the aim of our study was to assess the baseline markers of ischaemia-reperfusion injury (IRI) in claudicants and controls after acute treadmill exercise and to then examine the effect of a 3 month supervised exercise-training programme, on these markers, in the claudicant group. METHODS: forty-six claudicants and 22 age-matched controls undertook acute treadmill exercise. Neutrophil activation, degranulation, free radical damage and antioxidants were measured (by flow cytometry, ELISA, and chemiluminescence) at rest and at 5, 30 and 60 min post-exercise. Claudicants were then recruited into an intensive 3 month supervised exercise programme (SEP) after which the same parameters of IRI were reassessed at different time points, at 3 and 6 months. RESULTS: resting markers of IRI were similar in both groups. Exercise had no effect on the control group. Immediately after exercise, claudicants developed significant neutrophil activation and degranulation with free radical damage. This effect decreased sequentially after 3 months of exercise training. CONCLUSION: this study for the first time demonstrates that the exercise training of claudicants is beneficial, not only in terms of improving their walking distance, but also by decreasing the injurious effects of IRI that occur during claudication. Exercise training should be an essential part of the medical management of the majority of claudicants.

Adult↗
PubMed2002

Patients with chronic critical limb ischaemia have reduced total antioxidant capacity and impaired nutritional status.

INTRODUCTION: it has previously been demonstrated that total antioxidant capacity (TAC) can help predict which patients undergoing femoro-distal reconstruction are susceptible to postoperative infections. AIMS: the aims of this study were to examine if TAC is influenced by the nutritional state of the patient and the degree of ischaemia. PATIENTS AND METHODS: thirty patients with rest pain (21 men and 9 women), with a median age of 69 years and fifteen controls (9 men and 6 women), median age of 66 years, were studied. Nutritional status was assessed using serum albumin, body mass index (BMI), maximum voluntary contraction using a hand grip dynamometer and bioelectrical impedance to determine lean body mass. Blood was also taken for total antioxidant capacity (TAC). RESULTS: patients with chronic critical limb ischaemia (CCLI) had a lower TAC than controls (752 vs 1,130 micromol/l, p<0.05 Mann-Whitney U -test). There was no difference in serum albumin concentration between the CCLI group compared with controls (31 mmol/L vs 35 mmol/L, p>0.05 Mann-Whitney U-test). There was also no difference in BMI (23 vs 27, p>0.05 U-test) between the two groups. The other markers of nutrition including, maximum voluntary contractions (28.6 kg/m(2)vs 37.4 kg/m(2), p<0.05 M-W U-test), and lean body mass (3.0 vs 3.8 M-W U-test), showed a significant reduction in the vascular patients. CONCLUSION: TAC is significantly reduced in patients with CCLI and this may, in part, be explained by their impaired nutritional status.

Aged↗
PubMed2002

Pharmacological salvage of a combined distal bypass and free flap with catheter-directed thrombolysis.

With recent improvements in microvascular techniques, the use of combined distal bypass and free-flap transfer has been advocated for salvaging the critically ischaemic limb in extreme conditions. Distal bypass, however, carries an inherent risk of graft failure due to thrombosis, and this may threaten the viability of the free flap and, indeed, the lower limb. We present the case of a 66-year-old man with acute-on-chronic ischaemia of his left leg and rectus abdominis free flap. Despite a prolonged ischaemic time of 72 h, both were successfully salvaged using catheter-directed recombinant tissue plasminogen activator. This is previously unreported in the literature.

Aged↗
PubMed2002

Computational and experimental simulations of the haemodynamics at cuffed arterial bypass graft anastomoses.

The development of intimal hyperplasia at arterial bypass graft anastomoses is a major factor responsible for graft failure. A revised surgical technique, involving the incorporation of a small section of vein (vein cuff) into the distal anastomosis of polytetrafluoroethylene (PTFE) grafts, alters the distribution of intimal hyperplasia and improves graft performance. Numerical and in vitro flow visualization experiments have been conducted to identify the flow behaviour in the cuffed bypass model and to determine whether the improved performance of the cuffed system can be accounted for by haemodynamic factors. The flowfield at the cuffed anastomosis is characterized by an expansive recirculation. Separation occurs at the graft heel, and at the cuff toe as the blood enters the recipient artery. Wall shear stresses in the vicinity of the cuff heel are low, but high shear stresses and large spatial gradients in the shearing force act for a time on the artery floor. In the conventional model, a less disturbed flow prevails while the gradients of shear stress on the floor are smaller. Aspects of the anastomotic haemodynamics are worsened when the cuff is employed. The superior patency rates of cuffed bypasses may not be explained purely on the basis of local haemodynamic factors.

Anastomosis, Surgical↗
PubMed2002

Flexible tubular replicas of abdominal aortic aneurysms.

The aim of this study was to manufacture life-size, flexible, tubular replicas of human abdominal aortic aneurysms and the associated vasculature, suitable for use in a training simulator for endovascular procedures. Selective laser sintering was used to create a geometrically correct master model for each of ten anatomical variations. The masters were used to generate flexible latex replicas. The use of the replicas in the training simulator was demonstrated. In total ten silicone rubber models were produced. When connected into the training simulator and perfused at arterial pressure it was possible to deploy an endovascular stent under fluoroscopic control and to perform angiography. The study has shown that conventional rapid prototyping technology can be used to manufacture flexible, radiolucent replicas which provide a realistic training environment for endovascular procedures.

Angiography, Digital Subtraction↗
PubMed2002

False aneurysm of the peroneal artery: an unusual complication of femoro-peroneal bypass grafting.

Non-traumatic false aneurysm formation involving the native crural vessels is rare. We present the case of a false aneurysm of the native peroneal artery, which complicated femoro-peroneal bypass grafting. It seemed most likely to be of an infective aetiology, arising as a consequence of contiguous methicillin resistant Staphylococcus aureus wound infection. This was previously unreported in the literature. Successful management was achieved by primary suture, local wound debridement, excision of the distal graft and replacement with an interposition vein graft through uninfected tissue planes.

Aged↗