bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transcranial Doppler ultrasonography as a predictor of haemodynamically significant carotid stenosis
Authors: Byrd S , Wolfe J , Nicolaides A , Stansby G , Cheshire N , Thomas D , Mansfield A 
Published: March 2003

Abstract

Background
Transcranial Doppler (TCD) ultrasonography can detect evidence of collateral flow across the anterior communicating artery and/or the posterior communicating artery, which occurs when there is significant alteration of ‘inflow’ to the brain. The aim of the study was to determine the blood flow velocity produced by a carotid stenosis which produces this haemodynamic effect on the cerebral circulation and evokes collateral circulation.

Methods
Forty-eight patients with varying degrees of carotid stenosis (10 per cent to occlusion) who underwent both carotid duplex and TCD examination were reviewed. An ATL HDI 3000 ultrasound system was used for the carotid and TCD studies. The carotid examination recorded peak-systolic velocity (PSV) and end-diastolic velocity (EDV) in the carotid systems bilaterally. TCD recorded Doppler spectra from the bilateral middle cerebral, anterior cerebral, posterior cerebral, intracranial vertebral and basilar arteries. Collateral flow was assessed in two ways: ‘intracranial crossover’ collateral and ‘posterior to anterior’ collateral. Each internal carotid artery (ICA), together with the ipsilateral hemisphere, was analysed for the presence or absence of collateral flow. Data were expressed as mean(s.e.m.).

Results
The PSV of the group with collateral circulation was 472(14) cm s–1 and that of the group without collateral flow was 164(3) cm s–1 (P &lt; 0·0001, Mann–Whitney test). The respective EDVs were 158(13) and 58(7) cm s–1(P &lt; 0·0001).

Conclusion
PSVs and EDVs in the ICA, in conjunction with collateral flow measured by TCD, are indicators of a haemodynamically significant carotid lesion, and provide more information than two-dimensional imaging studies. In the future, parameters set by combining carotid duplex and TCD investigations may represent the ‘gold standard’ for evaluation of cerebral blood flow.
Limb outcome following failed femoropopliteal polytetrafluoroethylene bypass for intermittent claudication
Authors: Renwick P , Johnson B , Wilkinson A , Galloway J , McCollum P 
Published: March 2003

Abstract

Background
Femoropopliteal (FP) bypass using polytetrafluoroethylene (PTFE) is still considered by many surgeons to be a reasonable procedure for severe intermittent claudication (IC) without limb-threatening ischaemia. The consequences of FP graft failure were examined.

Methods
Over 8 years, 54 patients had 55 FP grafts (that subsequently occluded) inserted for severe IC (42 PTFE and 13 vein grafts) above (30) or below (25) the knee. There were no operative deaths. During the same interval a total of 191 FP grafts were placed, 100 of which were vein grafts. Patient demography and risk factor analysis was similar for both groups.

Results
Nineteen patients required amputation subsequent to a failed graft, all of these following PTFE grafts. Mean time to occlusion was 12·2 (range 0–79) months. For PTFE grafts, the mean(s.d.) ankle index rose from 0·51(0·14) to 0·95(0·15) after operation but fell to 0·25(0·15) after occlusion, confirming a highly significant deterioration from preoperative levels, which was not seen in vein graft occlusions.

Conclusion
Long-term FP bypass patency rates with vein are superior to those obtained with PTFE. Failed PTFE grafts show a significant deterioration in pressure indices compared with preoperative values. FP grafts for IC carry an intrinsic risk of limb loss which is much greater when vein is not used (P &lt; 0·001).
First year of a fast-track carotid duplex service
Authors: Bhatti T S , Harradine K L , Davies B , Earnshaw J J , Heather B P 
Published: March 2003

Abstract

Background
The risk of a major stroke after a transient ischaemic attack (TIA) is highest in the first 3 months after the onset of symptoms. Urgent endarterectomy in appropriate cases is recommended through a fast-track one-stop assessment clinic.

Methods
Local general practitioners (GPs) were informed that a duplex scan would be guaranteed within 14 days of referral of any patient who had a recent clearly documented TIA or amaurosis fugax. Referral letters were faxed and the scan was authorized by a consultant surgeon. Those with significant disease were seen in the clinic in preparation for operation. Non-significant results were conveyed by post to the GPs with no further action.

Results
In the first 12 months of the service, 90 scans were performed through the fast track. In the same interval 490 non-fast-track scans were done after request by a physician (38 per cent), geriatrician (24 per cent), neurologist (14 per cent), vascular surgeon (11 per cent), ophthalmologist (8 per cent) or others (4 per cent). Thirteen (14 per cent) of 90 patients in the fast-track group had carotid endarterectomy, with a median period between referral and operation of 30 (range 20–45) days and median time between onset of symptoms and surgery of 7 (range 4–58) weeks. Endarterectomy was carried out in 12 (2 per cent) of 490 patients in the routine group with a median duration between referral and operation of 127 (range 64–184) days.

Conclusion
A fast-track service can significantly reduce the time between referral and operation, and increase the number of endarterectomies. Urgent and appropriate referral from the GPs is vital for the service to work efficiently.
Outcome after ligation of infected false femoral aneurysms in intravenous drug abusers
Authors: Gan J , Leiberman D P , Pollock J G 
Published: March 2003

Abstract

Background
Infected false femoral aneurysm (IFFA) is a life-threatening complication of intravenous drug abuse and presents a difficult management problem for the vascular surgeon. Controversy exists regarding the best management. The choice lies between ligation and excision with immediate revascularization, and ligation and excision with observation; reconstruction is reserved for critical ischaemia.

Methods
After disappointing results with the former method it was decided to perform ligation and excision with observation as the initial treatment of IFFA. A 9-year experience of 28 patients treated at this hospital is reviewed.

Results
In 26 cases of primary ligation and excision of an IFFA there were no amputations and patients described claudication only in follow-up. In two cases of a second IFFA in the same limb, repeat ligation and excision resulted in one viable limb with claudication only and one above-knee amputation for non-viability. At 9-year follow-up (80 per cent complete), over 90 per cent of the patients were still drug abusers and therefore not suitable for revascularization. There were two deaths, both of which were drug related.

Conclusion
Ligation and excision of an IFFA is simple, effective and safe, and is the most appropriate method of dealing with these challenging patients.
Systematic review of intra-arterial thrombolytic therapy for peripheral vascular occlusions
Authors: Palfreyman S J , Michaels J A 
Published: March 2003

Abstract

Background
A systematic review of intra-arterial thrombolytic therapy for peripheral vascular occlusions was undertaken.

Methods
The four major electronic databases (Medline, Cinhal, Embase and The Cochrane Library) were searched to identify randomized controlled trials of thrombolytic therapy in the treatment of limb ischaemia. The search was limited to English language articles, or those that provided a sufficiently detailed English summary, and to articles published after 1980. Trials were considered for inclusion if they were randomized controlled trials, systematic reviews or meta-analyses. Data were extracted independently by two reviewers and aggregate outcomes were obtained using a random effects meta-analysis.

Results
A total of 32 articles were found but only 12 were assessed to be of sufficient quality to be included in the review. There was a distinct lack of large randomized controlled trials comparing thrombolysis with surgical management. The exceptions were the Thrombolysis or Peripheral Arterial Surgery (TOPAS) and Surgery versus Thrombolysis for Ischemia of the Lower Extremity (STILE) trials, but both had some methodological flaws. The STILE trial did not achieve the sample size originally determined and the TOPAS trials had a large number of contributing centres (113) compared with the sample size (548). Meta-analysis showed no significant differences between thrombolysis and surgery in terms of major amputation (relative risk (RR) 0·9 (95 per cent confidence interval 0·6–1·4)) and death (RR 1·2 (0·8–1·9)). However, there was an increased risk of residual ischaemia with thrombolysis (RR 1·8 (1·2–2·5)) and haemorrhage (RR 2·9 (1·1–7·9)). Patients who were shown to benefit from thrombolysis were those with short-duration ischaemia (RR reduction, 72 per cent; numbers needed to treat, three) and occluded grafts (RR reduction, 58 per cent; numbers needed to treat, four).

Conclusion
Despite the theoretical advantages of thrombolysis, there is still insufficient evidence to justify its widespread use except in patients with graft occlusions and short-duration ischaemia.
Outcome of iliac percutaneous transluminal angioplasty with and without the use of stents in patients with intermittent claudication
Authors: Beattie G C , Brittenden J , Gillespie I , McBride K , McInnes G , Bradbury A W 
Published: March 2003

Abstract

Background
Despite the absence of controlled data supporting endovascular treatment of iliac disease in patients with intermittent claudication (IC), there has been a significant increase in iliac percutaneous transluminal angioplasty (PTA), and in particular iliac stenting, in recent years. The clinical and haemodynamic outcome of iliac PTA, with and without stenting, was assessed in patients with IC.

Methods
A prospectively gathered computerized database of iliac PTA (n = 203) and stenting (n = 88), performed between 1 January 1991 and 31 December 1997, was analysed.

Results
Occlusive disease was significantly more likely than stenotic disease to be treated by primary stent deployment (19 of 88, 22 per cent) than PTA alone (11 of 203, 5 per cent) (P &lt; 0·01, χ2 test), as were lesions in the common iliac artery (common 69 of 214 (32 per cent) versus external 14 of 65 (22 per cent); P&lt; 0·05, χ2 test). Primary stent placement was associated with a significant increase in morbidity that delayed hospital stay (13 of 88 (15 per cent) versus seven of 203 (3 per cent); P&lt; 0·05, χ2 test). Emergency revascularization was required in four patients who underwent PTA (2 per cent) and two who had stenting (2 per cent) (P not significant).

Conclusion
Iliac stenting is associated with a significant increase in morbidity but with no improvement in symptomatic or haemodynamic outcome. These results do not justify the increased expense associated with the routine use of iliac stents.
Two-year follow-up after acute thromboembolic lower limb ischaemia: the importance of continuing warfarin treatment
Authors: Campbell W B , Ridler B M F , Szymanska T H 
Published: March 2003

Abstract

Background
The Vascular Surgical Society carried out an audit of follow-up after acute thromboembolic lower limb ischaemia.

Methods
The audit of acute lower limb ischaemia was done between 1 January and 31 March 1996 and included 474 patients. This report describes a 2-year follow-up of patients with a diagnosis of thrombosis or embolism who survived 30 days. Details were obtained for 214 (75 per cent) of 287 patients: half (107) were men, and the age range was 21–96 (mean 74) years.

Results
Amputation of the leg affected initially had been required (after 30 days) in 12 per cent. Further acute leg ischaemia had occurred in 11 per cent, and 9 per cent had undergone arterial reconstruction (11), angioplasty (seven) or thrombolysis (two). Major medical events were reported in 31 per cent and 35 per cent had died during the 2-year period. After the episode of acute ischaemia, warfarin was started in 57 per cent of patients, but was continued in only 43 per cent. Reasons for stopping were seldom known, nor was duration of treatment (range 1–22 (median 6) months in reported cases). Significantly more patients who were not on warfarin suffered recurrent acute limb ischaemia (19 versus 3 per cent; P&lt; 0·01). No significant association was found between recurrent acute ischaemia and initial diagnosis of embolism, thrombosis or atrial fibrillation (but numbers of recurrences in each group were small).

Conclusion
The incidence of recurrent acute thromboembolic limb ischaemia up to 2 years was significantly lower in patients treated with warfarin. Warfarin treatment is often stopped for no clear reason, especially in the elderly. Explicit advice about long-term warfarin therapy should be given when these patients are discharged from hospital.
Angiogenesis and the atherosclerotic carotid plaque: association between symptomatology and plaque morphology
Authors: McCarthy M J , Loftus I M , Thompson M M , Jones L , London N J M , Bell P R F , Naylor A R , Brindle N P J 
Published: March 2003

Abstract

Background
Symptomatic carotid disease due to thromboembolism has been associated with acute plaque instability and intraplaque haemorrhage. These features may be influenced by the fragility and position of plaque neovessels. The purpose of this study was, therefore, to determine whether any association existed between neovessel density, position, morphology and thromboembolic sequelae.

Methods
Carotid endarterectomy (CEA) samples were collected from 15 asymptomatic patients with greater than 80 per cent stenosis and from 13 patients with greater than 80 per cent stenosis and symptoms within 30 days of CEA. Groups were matched for sex, age, risk factors and plaque size. Samples were stained with haematoxylin and eosin, and Van Gieson stains. An endothelial-specific antibody to CD31 was used for immunohistochemistry. Plaques were assessed for histological characteristics while neovessels were counted and characterized by size, site and shape.

Results
There were more neovessels in plaques (P&lt; 0·00001) and fibrous caps (P&lt; 0·0001) from symptomatic than asymptomatic patients. Symptomatic plaque neovessels were larger in size (P&lt; 0·004) and more irregular in shape. There was a significant increase in plaque necrosis and rupture in symptomatic plaques. Plaque haemorrhage and rupture were associated with more neovessels within the plaque (P&lt; 0·02, P&lt; 0·001) and fibrous cap (P&lt; 0·05, P&lt; 0·004). Patients with preoperative or intraoperative embolization had more plaque and fibrous cap neovessels (P&lt; 0·03, P&lt; 0·001).

Conclusion
Symptomatic carotid disease is associated with increased neovascularization within the atherosclerotic plaque and fibrous cap; these vessels appear larger in size, more irregular in shape and may contribute to plaque instability and onset of thromboembolic events.
Uptake of tetracycline in aortic aneurysms: influence on inflammation and proteolysis
Authors: Franklin I J , Harley S L , Greenhalgh R M , Powell J T 
Published: March 2003

Abstract

Background
Derivatives of tetracycline (TC), through their inhibition of matrix metalloproteinases (MMPs), have been suggested as potential medical therapy to limit growth of abdominal aortic aneurysms (AAAs), but penetration of the aortic wall in vivo has not been demonstrated. The uptake and concentration of TC in aneurysm wall, and its effect on MMP and cytokine production, were investigated.

Methods
Patients undergoing elective AAA repair (n = 5) were given a single bolus of intravenous TC 500 mg on induction of anaesthesia. The TC concentrations achieved in serum, aneurysm wall and mural thrombus were determined using a microbiological assay. In separate patients, not given TC, AAA biopsy explants were established and the effect of TC (0, 10 and 100 µg ml–1) on hydroxyproline, MMP-9 and cytokine (MCP-1 and interleukin (IL) 6) secretion were investigated using colorimetric assays and immunoassays.

Results
At the time of aortic cross-clamping median TC concentration was 9 (range 5–12) µg ml–1 in serum, 2·7 (1·3–9·6) µg g–1 in AAA wall and nil in mural thrombus (see Table).

Conclusion
TC rapidly penetrates AAA wall in vivo and inhibits MMP-9 and MCP-1 release by AAA explants. This suggests that TCs have the potential to limit aneurysm growth.
Angioplasty reverses the systemic effects of exercise in intermittent claudication
Authors: Lewis D R , Day A , Baird R N , Smith F C T , Lamont P M 
Published: March 2003

Abstract

Background
The choice between exercise training and percutaneous transluminal angioplasty (PTA) in the treatment of intermittent claudication (IC) remains controversial. Exercise is known to induce systemic effects in claudicants. This study aimed to determine whether such systemic effects are reversed by PTA.

Methods
Ten patients with IC were recruited before PTA. Having emptied the bladder and rested for 1 h, pre-exercise blood and urine samples were collected. Patients underwent treadmill exercise to their maximum walking time and further 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 Willebrand 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 was repeated. Statistical analysis was by Wilcoxon signed rank test.

Results
Following PTA, all patients walked for 5 min on the treadmill. All patients had a significant exercise-induced fall in ankle pressure that was reversed by PTA. Changes in TAC are shown in the Table. There was no significant change in vWF. Exercise in claudicants induced a significant increase in median ACR (pre/post exercise (pre-exercise value divided by post-exercise value) 0·8; 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.

Conclusion
Exercise-induced changes in renal glomerular (ACR) and tubular function (RBP: Cr) in claudicants were reversed by successful angioplasty. PTA reduced the systemic TAC before and after exercise suggesting a reduced free radical challenge.
Early and long-term results after necrosectomy for necrotizing pancreatitis
Authors: Tzovaras G , Parks R W , Diamond T , Rowlands B J 
Published: March 2003

Abstract

Background
Necrotizing pancreatitis is a difficult clinical problem associated with significant mortality and morbidity rates. Indications for surgical intervention, and the timing and type of intervention, remain controversial issues. A 10-year experience in the management of this condition in a tertiary referral centre is reviewed; treatment policies and early and long-term results are reported.

Methods
Between 1987 and 1997, 39 consecutive patients (32 men, seven women), with a mean age of 47 (range 13–74) years, underwent necrosectomy for severe necrotizing pancreatitis. Diagnosis was confirmed by contrast-enhanced computed tomography. Twenty-nine patients were referred from other hospitals in Northern Ireland. The aetiology included gallstones (15), alcohol (ten), idiopathic (seven), surgery (two), endoscopic retrograde cholangiopancreatography (two), blunt trauma (one), hyperlipidaemia (one) and pancreas divisum (one). Mean Acute Physiology And Chronic Health Evaluation (APACHE) II score on admission or arrival was 2 (range 5–21). Indications for surgical intervention were clinical deterioration with development of multiple organ failure, despite maximal medical support in the intensive care unit (ICU), or positive fine-needle aspiration for micro-organisms or radiographic evidence of infected necrosis (i.e. presence of gas within peripancreatic collection). The mean interval from onset to intervention was 23 (range 9–47) days. In 13 patients a conventional approach (necrosectomy with primary closure over drains) was used, 14 patients underwent planned staged necrosectomy with delayed closure over drains and in 12 patients necrosectomy with open laparostomy was undertaken.

Results
There were five deaths and 14 patients experienced significant hospital morbidity (fistula, ten; pseudocyst, two; renal failure, two). Variables which correlated with mortality rate were higher APACHE II score, acute renal failure requiring dialysis and early intervention. There was no difference in either mortality or morbidity rate between infected and sterile necrosis, or between the three surgical techniques. Long-term morbidity occurred in 20 surviving patients (incisional hernia, ten; endocrine pancreatic insufficiency, nine; exocrine pancreatic insufficiency, two; pseudocyst, two; chronic renal failure, two; recurrent pancreatitis, one; and chronic pain, one).

Conclusion
A low mortality rate can be achieved in patients with severe necrotizing pancreatitis with aggressive surgical intervention. Early maximal medical treatment and ICU support is essential before intervention, which should preferably be avoided early in the course of the disease and should be based on well defined criteria. The long-term morbidity rate remains high, although not always severe. This emphasizes the need for close follow-up.
Prevalence of R117H mutation in the cationic trypsinogen gene in patients with hereditary pancreatitis
Authors: Creighton J E , Lyall R , Wilson D I , Curtis A , Charnley R M 
Published: March 2003

Abstract

Background
The R117H mutation of the cationic trypsinogen (CT) gene (G to A mutation in exon 3), located on chromosome 7q35, is one of the known mutations that is linked to hereditary pancreatitis (HP) and is thought to alter a trypsin recognition site responsible for the breakdown of inappropriately activated trypsinogen so resulting in pancreatitis. The aim of this study was to determine the prevalence of this mutation in patients with HP and to correlate presence of the mutation with disease characteristics.

Methods
Polymerase chain reaction amplification of the third exon of the CT gene was performed on blood DNA. This was digested by the restriction endonuclease Afl III and fragments were sized by agarose gel electrophoresis. Haplotype analysis was carried out using three short tandem repeat markers in the region of the CT gene.

Results
Seven discrete families with HP (three to seven generations) were identified (22 affected individuals). The mutation was present in individuals from three of the seven families. It was absent in all affected individuals from the other four families. A higher proportion of patients requiring pancreatic surgery was seen in families expressing this mutation (eight of 14 versus one of eight, P = 0·016). Mean(s.d.) age of onset was similar in both groups (7·9(5·8) versus 6·3(10·1) years, P = 0·13). In the affected families, the same high-risk haplotype was present in two families, suggesting a common ancestor. The third family carried a unique haplotype.

Conclusion
A single G to A mutation in the third exon of the CT gene was found in three families with HP originating from this region and appears to be associated with more severe disease. Further work is being undertaken to analyse the CT gene more fully in families in which this common first mutation was not identified.