bluuebunny/crossref_metadata_2025_split huggingface dataset:
Durability of angioplasty in treating severe leg ischaemia
Authors: Molloy K , Nasim A , London N J M , Naylor A R , Bell P R F , Fishwick G , Bolia A , Thompson M M 
Published: July 2002

Abstract

Background
Percutaneous transluminal angioplasty (PTA) has recently been accepted as a valuable therapeutic option in patients with severe limb ischaemia. However, despite the increasing use of this technique, there have been concerns that the long-term efficacy of PTA is inferior to that of surgical revascularization. This prospective study reports the outcome of an unselected cohort of patients who underwent balloon angioplasty for severe lower limb ischaemia in a single centre.

Methods
During 1997, 108 patients with 133 severely ischaemic legs were treated by PTA. The median age of the patients (49 per cent men) was 76 years. Symptoms were rest pain in 31 per cent, ischaemic ulceration in 56 per cent and gangrene in 13 per cent. The distribution of risk factors was typical: diabetes 32 per cent, ischaemic heart disease 18 per cent and stroke 16 per cent. Median (interquartile range) follow-up was 16 (12–19) months. There was a mean of 1·7 angioplasty sites per patient, distributed in the iliofemoral (14 per cent), superficial femoral (42 per cent), popliteal (18 per cent) and crural (26 per cent) arteries. PTA was performed luminally in 20 per cent of cases and subintimally in the remainder. Overall, 67 per cent of the lesions were complete occlusions with a median length of 20 (10–40) cm.

Results
Technical success was achieved in 104 limbs, with 29 failures. The outcome of patients with a failed angioplasty (29) was poor, with 14 requiring bypass surgery, 11 undergoing a major amputation and 32 per cent dying after the procedure. In contrast, patients having a technically successful angioplasty had a good outcome after a median follow-up of 16 (12–19) months. In this group there was a 30 per cent overall mortality rate during follow-up. However, 85 per cent of the patients had no symptoms of critical ischaemia and the limb salvage rate was 92 per cent.

Conclusion
PTA is an effective and durable procedure in patients with critical leg ischaemia, with results comparable to those of historical surgical controls. Technical failure of PTA is, however, associated with a dire outcome.
Dextran-40 stimulates resting platelets and binds more avidly to activated platelets
Authors: Hayes P D , Box H , Tull S , Bell P R F , Goodall A H , Naylor A R 
Published: July 2002

Abstract

Background
A programme of monitoring and treatment with low-dose 10 per cent Dextran-40 (20 ml h−1) can successfully prevent thrombotic occlusion of the carotid artery after endarterectomy. This is a clinically effective treatment, over 500 CEAs have been performed with no thrombotic strokes, but little is known about the mechanism by which low-dose Dextran-40 affects platelet-rich thrombus formation.

Methods
In study 1, platelets from ten patients undergoing CEA were collected in a standardized manner. The response to therapeutic doses of Dextran-40 was assessed in vitro using whole-blood flow cytometric analysis of fibrinogen binding in response to adenosine 5′-diphosphate (ADP) and thrombin. Platelet aggregation in response to ADP and collagen was recorded. In study 2, blood collected from ten normal subjects was incubated with fluorescently labelled Dextran-40 and binding was measured using flow cytometry. In these experiments blood was either first incubated for 10 min with the FITC–Dextran-40 and then activated with thrombin 0·4 units ml−1 or activated with thrombin 0·4 units ml−1 for 10 min before incubation with FITC–Dextran-40.

Results
In study 1, reincubation of the patients' blood with Dextran-40 increased fibrinogen binding to resting platelets by 352 per cent (P &lt; 0·05) and to ADP-stimulated platelets by 39 per cent (P &lt; 0·05). Dextran-40 also increased fibrinogen binding in response to thrombin although this difference was not significant (P = 0·12), and increased platelet aggregation in response to ADP (48 per cent) and collagen (32 per cent) (P &lt; 0·05 for both). In study 2, fluorescently labelled Dextran-40 bound to the surface of resting platelets from normal subjects in a dose-dependent manner, and caused platelet activation, as measured by increased P-selectin expression. Incubation with Dextran followed by activation caused a 28 per cent increase in Dextran binding; however, if the platelets were activated first and then exposed to Dextran the binding increased 94 per cent (P = 0·001).

Conclusion
Low-dose Dextran-40 is very effective in preventing thromboembolic complications after CEA. However, in vitro, Dextran-40 has a direct stimulatory effect on platelets. Dextran-40 binds to platelets and shows preferential binding to activated, compared with resting, platelets. Dextran may exert a beneficial antiplatelet/antithrombotic effect in vivo by inhibiting the recruitment of activated platelets to a growing thrombus.
Clinical governance and the vascular surgeon
Authors: Irvine C , Grayson D , Lusby R J 
Published: July 2002

Abstract

Background
Monitoring of surgeons and their results is currently in question. The validity and the practicality of audit to determine substandard results is undetermined. To test the instrument of audit, statistical modelling was applied to two indicator vascular procedures, elective abdominal aortic aneurysm (AAA) repair and carotid endarterectomy (CEA), with accepted adverse event rates.

Methods
Binomial statistical models for varying adverse event rates were constructed. A power calculation was used in an attempt to predict the case numbers required to determine substandard results for individual surgeons and vascular units. Statistical conventions of power (80 per cent) and upper criterion of rarity (0·05) were used. Previous activity rates for CEA and elective AAA repair were used to predict the time taken to gather these data.

Results
Base rates of 3 and 6 per cent were considered, along with a range of alternate practice. Number of adverse events, number of operations to be studied and the time that this would take are shown in the Table.

Conclusion
Statistical modelling demands assumptions about accepted adverse event rates, confidence criteria and what constitutes substandard results. Large numbers of patient data are required even for common operations with accepted adverse event rates. These data raise serious questions as to the feasibility of performing clinical governance on the basis of crude morbidity and mortality event rates alone.
Effect of chronic renal failure on postoperative mortality rate following arterial reconstruction
Authors: Ray S A , Keast-Butler O D , Wood C M , Scoble J E , Taylor P R 
Published: July 2002

Abstract

Background
Chronic renal failure (CRF) is both a risk factor for, and a consequence of, peripheral arterial disease. There is also increasing evidence that patients with CRF have a higher mortality rate following arterial reconstruction, but it is not known whether this is different for aneurysmal or occlusive disease.

Methods
Over 8 years 1718 consecutive arterial reconstructions performed under the care of one consultant were studied prospectively. Patients were defined as having CRF if at the time of surgery the serum creatinine measured more than 400 μmol 1−1, they were undergoing dialysis or they had received a renal transplant. The in-hospital postoperative mortality rate was compared between patients with and without CRF and analysed according to the urgency as well as the type of arterial reconstruction.

Results
Sixty-nine patients (4 per cent) undergoing arterial reconstruction over the study period were defined as having CRF. Sixteen (23 per cent) of these died following surgery (myocardial infarct seven, multiple organ failure three, stroke one, mesenteric thrombosis one, paraplegia one, respiratory failure one, pneumonia one, failure to thrive one), in comparison to 120 (7·3 per cent) of 1649 patients without CRF. The mortality rate in patients with CRF was highest in those who underwent urgent/emergency surgery and those who had reconstruction for occlusive disease.

Conclusion
Patients with CRF have a threefold increase in mortality rate following arterial reconstruction. Patients undergoing infrainguinal bypass are at particular risk and should be carefully selected and counselled.
Prevalence of popliteal aneurysm in patients with abdominal aortic aneurysm or intermittent claudication
Authors: Phillips D , Hussain S T , Minor J , Collin J 
Published: July 2002

Abstract

Background
The prevalence of abdominal aortic aneurysm (AAA) in defined risk groups has been well established but the prevalence of popliteal artery aneurysm is unknown. The aim was to discover the prevalence of popliteal artery aneurysm in patients with known AAA and in patients attending a vascular clinic with intermittent claudication (IC).

Methods
The maximum anterior posterior diameter of the popliteal artery was measured by duplex sonography in 200 patients with known AAA attending an established surveillance programme and 325 patients with IC but no aortic aneurysm attending a vascular clinic. In all patients sex, age and height were recorded.

Results

Conclusion
The prevalence of popliteal aneurysm is 2·0 (confidence interval 0–3·9) per cent in patients with AAA and 0·6 (0·2–1·4) per cent in patients with IC. Compared with claudicants, patients with AAA are significantly older and taller, more likely to be men and have larger popliteal arteries. The prevalence of popliteal aneurysm is too low, even in suspected high-risk groups, for screening to be worthwhile.
RETA: update on the short-term (30 day) and long-term (1 and 2 years) results of endovascular repair of abdominal aortic aneurysms
Authors: Thomas S M , Gaines P A , Beard J D 
Published: July 2002

Abstract

Background
The updated results from the Registry of Endovascular Treatment of Aneurysms (RETA) for short- and long term outcomes from 3 years of data collection are presented.

Methods
Some 611 patients were submitted to RETA from January 1996 to December 1999 from 31 centres. In the same period 1-year follow-up was received for 299 of the 340 cases requested (88 per cent return rate) and 2-year follow-up for 88 of the 155 cases requested (57 per cent return rate).

Results
At 30 days 90 per cent of abdominal aortic aneurysms (AAA) were excluded. The rate of conversion to open repair was 5 per cent. Complications occurred in 25 per cent of patients. The overall 30-day mortality rate was 7 per cent with significantly more deaths in the aortouni-iliac and crossover groups (12 versus 4 per cent; adjusted odds ratio (OR) 2·6 (95 per cent confidence interval (c.i.) 1·2–5·9); P = 0·018), in unfit patients (18 versus 4 per cent; adjusted OR 4·3 (95 per cent c.i. 2·0–9·5); P &lt; 0·001) and in patients with larger aneurysms (10 versus 2 per cent; adjusted OR 4·4 (95 per cent c.i. 1·4–13); P = 0·009). At 1 year the mortality rate was 11 per cent, with four deaths (1 per cent) due to ruptured AAA. New complications were reported in 53 patients (20 per cent) with 31 (12 per cent) related to the device or AAA. In the second year of follow-up the mortality rate was 11 per cent with one death (1 per cent) due to ruptured AAA. New complications in the second year after device placement were reported in 24 per cent of patients, with 16 (20 per cent) related to the device or AAA. The cumulative endoleak-free survival for all patients was 57 per cent at 2 years.

Conclusion
The 30-day mortality rate for endovascular repair was comparable to reported results for conventional surgery, particularly in fit patients. There was a relatively high complication rate at follow-up, with ruptures reported. Most complications had endovascular treatment.
Infrainguinal bypass grafting for critical ischaemia in the hands of trainees
Authors: Papp L , Evans S M , Kelman J , Chalmers R T A , Murie J A , Bradbury A W 
Published: July 2002

Abstract

Background
Changes in surgical training mean that operative experience must be gained more efficiently. However, it is important to demonstrate that increasing training opportunities are not associated with inferior patient outcome. The immediate and long-term outcomes of patients undergoing infrainguinal bypass surgery by consultants and trainees were compared.

Methods
A prospectively gathered database of 1077 infrainguinal bypasses performed on 1003 patients for chronic critical limb ischaemia between 1 January 1983 and 31 December 1998 in a single regional vascular unit was evaluated.

Results
Consultants performed 733 operations (68·1 per cent), 347 (47·3 per cent) above-knee, 257 (35·1 per cent) below-knee popliteal, 121 (16·5 per cent) crural and eight (1·1 per cent) other procedures. Of 344 trainee operations, 170 (49·4 per cent) were above-knee, 122 (35·5 per cent) below-knee, 48 (14·0 per cent) crural and four (1·2 per cent) other operations. There was no significant difference in 30-day mortality rate between consultant (2·8 per cent) and trainee (2·0 per cent) operations, nor was there any significant difference in patency or limb salvage rates at 36 months (Table). There was a trend towards reduced graft patency in trainee crural bypasses but this was not statistically significant (35·9 versus 56·2 per cent; P = 0·14, log rank test).

Conclusion
These data suggest that, with appropriate case selection and supervision, training in femoropopliteal and crural bypass grafting does not compromise early or long-term outcome.
Vascular access for haemodialysis
Authors: Murphy G J , White S A , Nicholson M L 
Published: July 2002

Abstract

Background
The recent expansion of renal replacement therapy programmes has been associated with an increase in the number and complexity of patients requiring permanent vascular access. The introduction of strategies designed to maximize secondary access patency is, therefore, increasingly important as a means of prolonging patient survival on dialysis, reducing morbidity and reducing the escalating cost of such programmes.

Methods
A review of the current literature on the planning of vascular access, access surveillance methods and treatment of the most common complications was performed.

Results
Multidisciplinary vascular access planning, increased use of preoperative imaging and the preferential use of autogeneous vein are essential to obtain the best long-term results. While vascular access surveillance, in particular protocols involving direct measurement of access flow, enables the prospective detection and treatment of venous stenosis, the precise indications for treating venous stenosis remain unclear. Surgical revision remains the gold standard for the treatment of failing arteriovenous fistulas, but recent advances in interventional radiological techniques along with the suitability of arteriovenous fistulas for percutaneous intervention may offer an effective alternative. The effect of both these interventions on access patency requires comparison in a randomized trial.

Conclusion
The introduction of strategies to improve access patency rates will change vascular access surgical practice away from the construction of new fistulas towards an increase in outpatient percutaneous intervention and surgical revisional procedures. The role of surgical interventions requires clearer definition.
Hypertonic saline attenuates end-organ damage in an experimental model of acute pancreatitis
Authors: Shields C J , Winter D C , Sookhai S , Ryan L , Kirwan W O , Redmond H P 
Published: July 2002

Abstract

Background
Hypertonic saline (HTS) has been noted previously to reduce neutrophil activation. The aim of this study was to elucidate the effect of hypertonic resuscitation on the development of end-organ damage in an animal model of pancreatitis.

Methods
Pancreatitis was induced in Sprague–Dawley rats by intraperitoneal injection of 20 per cent l-arginine. Animals were randomized into four groups (each n = 8): controls; pancreatitis without intervention; pancreatitis plus intravenous resuscitation with normal saline (0·9 per cent sodium chloride 2 ml/kg) at 24 and 48 h; or HTS (7·5 per cent sodium chloride 2 ml/kg) at these time points. Pulmonary endothelial leakage was assessed by measurement of lung wet: dry ratios, bronchoalveolar lavage protein and myeloperoxidase activity.

Results
Animals that received HTS showed less pancreatic damage than those resuscitated with normal saline (1·0 versus 3·0; P = 0·04). Lung injury scores were also significantly diminished in the HTS group (1·0 versus 3·5; P = 0·03). Pulmonary neutrophil sequestration (myeloperoxidase activity 1·80 units/g) and increased endothelial permeability (bronchoalveolar lavage protein content 1287 μg/ml) were evident in animals resuscitated with normal saline compared with HTS (1·22 units/g and 277 μg/ml respectively; P &lt; 0·02).

Conclusion
HTS resuscitation results in a significant attenuation of end-organ injury following a systemic inflammatory response to severe pancreatitis.
Dose–response relationship between plasma ACTH and serum cortisol in the insulin–hypoglycaemia test in 25 healthy subjects and 109 patients with pituitary disease
Authors: Tuchelt H. , Dekker K. , Bähr V. , Oelkers W. 
Published: July 2002

OBJECTIVE: The insulin hypoglycaemia test (IHT) is believed to be the most reliable test for evaluating the entire hypothalamo–pituitary–adrenal (HPA) axis. The lower limit for the normal peak serum cortisol response has been reported to be between 500 and 580 nmol/l. Reference levels for a normal plasma ACTH response have not been reported recently. DESIGN AND PATIENTS: We performed the IHT in 25 healthy subjects and in 109 patients with proven or suspected pituitary disorders with serial measurements of serum or plasma cortisol and of plasma ACTH, in order to establish reference levels and to study the dose–response relationship between ACTH and cortisol in this test. In most patients, other pituitary hormonal axes were evaluated in addition. RESULTS:With the cortisol kit from Diagnostic Products Corporation (DPC), serum cortisol was about 13% lower than plasma (EDTA) levels with an excellent correlation between serum and plasma (r = 0.976; P < 0.001). In the normals, the lower limit of the cortisol response (mean cortisol peak level minus 2 SD.) was 570 nmol/l for plasma and 500 nmol/l (calculated) for serum, while the lower limit of the ACTH response was 17.6 pmol/l (80 ng/l). In normals, the cortisol response was independent of the magnitude of the ACTH response. Seventeen out of 30 patients with ACTH responses to levels < 8.8 pmol/l (< 40 ng/l) had subnormal cortisol responses. However, 38 of the patients with pituitary disease had normal cortisol responses in spite of subnormal ACTH responses (group 2), while 47 patients had completely normal IHT results (group 1). Patients in group 2 had more often additional pituitary hormone deficiencies than those of group 1. The dose–response relationship between ACTH and cortisol in the patients resembled a dose–response curve that had been set up previously in normal subjects who received incremental doses of subcutaneous human ACTH (1–39). CONCLUSIONS:The normal increment of plasma ACTH in the IHT is greater than necessary for stimulating serum cortisol to levels > 500 nmol/l. Patients with a subnormal ACTH but normal cortisol response in the IHT have a decreased ACTH secretory reserve. It is unlikely that they are at increased risk of developing an adrenal crisis perioperatively or in other stressful situations unless pituitary function deteriorates. The ACTH‐cortisol relationship in the IHT performed in patients with pituirary disease shows no sharp dividing line between normality and disease, and whether a patient needs permanent glucocorticoid substution is a discretionary decision.
Solubility, sorption and desorption of native and added cadmium in relation to properties of soils in New Zealand
Authors: Gray C. W. , Mclaren R. G. , Roberts A. H. C. , Condron L. M. 
Published: July 2002

SummarySolution cadmium (Cd) concentrations and sorption and desorption of native and added Cd were studied in a range of New Zealand soils. The concentration of Cd in solution and the concentrations and patterns of native soil Cd desorbed and added Cd sorbed and desorbed varied greatly between the 29 soils studied. Correlation analysis revealed that pH was the most dominant soil variable affecting solution Cd concentration and sorption and desorption of native and added Cd in these soils. However, organic matter, cation exchange capacity (CEC) and total soil Cd were also found to be important. Multiple regression analysis showed that the log concentration of Cd in solution was strongly related to soil pH, organic matter and total Cd, which in combination explained 76% of the variation between soils. When data from the present study were combined into a single multiple regression with soil data from a previously published study, the equation generated could explain 81% of the variation in log Cd solution concentration. This reinforces the importance of pH, organic matter and total Cd in controlling solution Cd concentrations. Simple linear regression analysis could at best explain 53% of the total variation in Cd sorption or desorption for the soils studied. Multiple regression analysis showed that native Cd desorption was related to pH, organic matter and total Cd, which in combination explained 85% of the variation between soils. For sorption of Cd (from 2 μg Cd g–1 soil added), pH and organic matter in combination explained 75% of the variation between soils. However, for added Cd desorption (%), pH and CEC explained 77%. It is clear that the combined effects of a range of soil properties control the concentration of Cd in solution, and of sorption and desorption of Cd in soils. The fraction of potentially desorbable added Cd in soils could also be predicted from a soil’s Kd value. This could have value for assessing both the mobility of Cd in soil and its likely availability to plants.
Melanoma in Kauai, Hawaii, 1981–1990: the significance of in situ melanoma and the incidence trend
Authors: Chuang Tsu‐Yi , Charles Jonathan , Reizner George T. , Elpern David J. , Farmer Evan R. 
Published: July 2002

BackgroundThe incidence of melanoma has often been portrayed as reaching ‘epidemic’ proportions. The reality of such an epidemic is, however, not clearly established due to the methods of data collection and interpretation. The population‐based incidence data and incidence trend of melanoma from the Island of Kauai, Hawaii provide an illustration of this ‘epidemic’.MethodsWe used medical records housed at the dermatology clinic and pathology laboratory in Kauai to: identify residents of Kauai who had their first melanoma during the years 1981–1990; and to measure the 10‐year population‐based incidence of melanoma.ResultsIn Caucasians: A total of 53 Caucasian residents (29 men and 24 women), were identified with an initial episode of melanoma (MM) during the 10‐year period. The average annual standardized incidence rate per 100,000 Kauai Caucasian residents was 36. Whereas the incidence of in‐situ MM increased during the 10‐year period, the incidence of invasive MM did not. The average patient age was 55 years. The trunk and the limbs were the most common anatomic sites of MM. In men, one third of MM occur on the back. In women, one third develop on the leg/thigh. Three patients (6%) had metastasis and eventually died of MM. Thirteen patients (25%) had other skin cancers such as basal cell carcinoma and squamous cell carcinoma at some time. In Filipinos, Japanese and Hawaiians: Three Filipinos (all women), two Japanese (one man and one woman) and one Hawaiian (man) had melanoma. The standardized incidence rates, to the U.S.A. Caucasian population, were 3.1, 0.8 and 2.1 per 100,000 residents, respectively.ConclusionsThe melanoma incidence in Kauai is one of the highest rates documented in the U.S.A. However, a decreased incidence of invasive melanoma during the 10‐year period was unexpected. The finding of nonmelanoma skin cancer in these patients supports a common etiology among these skin cancers.