Analysis of primary care electronic health record data of people living with hepatitis B virus: infection and hepatocellular carcinoma risk associated with socio-economic deprivation

OBJECTIVES

We set out to characterise chronic hepatitis B (CHB) in the primary care population in England and investigate risk factors for progression to hepatocellular carcinoma (HCC).

STUDY DESIGN

Retrospective cohort study.

METHODS

We identified 8039 individuals with CHB in individuals aged ≥18 years between 1999 and 2019 in the English primary care database QResearch. HCC risk factors were investigated using Cox proportional hazards modelling.

RESULTS

Most of those with a record of CHB were males (60%) of non-White ethnicity (>70%), and a high proportion were in the most deprived Townsend deprivation quintile (44%). Among 7029 individuals with longitudinal data, 161 HCC cases occurred. Increased HCC hazards were significantly associated with male sex (adjusted hazards ratio [aHR] 3.17, 95% confidence interval [95% CI] 1.92-5.23), in the fifth deprivation quintile as compared to the third quintile (aHR 1.69, 95% CI 1.01-2.84), with older age (for age groups 56-65 and ≥66 years, compared to 26-35 years, aHRs 2.82 [95% CI 1.45-5.46] and 3.76 [95% CI 1.79-7.9], respectively), Caribbean ethnicity (aHR 3.32, 95% CI 1.43-7.71, compared to White ethnicity), ascites (aHR 3.15, 95% CI 1.30-7.67), cirrhosis (aHR 6.55, 95% CI 4.57-9.38) and peptic ulcer disease (aHR 2.26, 95% CI 1.45-3.51).

CONCLUSIONS

Targeting interventions and HCC surveillance at vulnerable groups is essential to improve CHB outcomes and to support progress towards international goals for the elimination of hepatitis infection as a public health threat.

A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

Multicentre randomised controlled trial of the clinical and cost-effectiveness of a bypass-surgery-first versus a balloon-angioplasty-first revascularisation strategy for severe limb ischaemia due to infrainguinal disease. The Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL) trial

OBJECTIVE

To compare a 'bypass-surgery-first' with a 'balloon-angioplasty-first' revascularisation strategy in patients with severe limb ischaemia (SLI) due to infrainguinal disease requiring immediate/early revascularisation.

DESIGN

A stratified randomised controlled trial. A Delphi consensus study of vascular surgeons' and interventional radiologists' views on SLI treatment was performed before the trial.

SETTING

Twenty-seven UK hospitals.

PARTICIPANTS

Patients presenting with SLI as the result of infrainguinal atherosclerosis and who, in the opinion of the responsible consultant vascular surgeon and interventional radiologist, required and were suitable for both surgery and angioplasty.

INTERVENTIONS

Patients were randomised to either 'bypass-surgery-first' or 'balloon-angioplasty-first' revascularisation strategies.

MAIN OUTCOME MEASURES

The primary end point was amputation-free survival (AFS); secondary end points were overall survival (OS), health-related quality of life (HRQoL) and cost-effective use of hospital resources.

RESULTS

AFS at 1 and 3 years was not significantly different for surgery and angioplasty. Interim analysis showed that surgery was associated with significantly lower immediate failure, higher 30-day morbidity and lower 12-month reintervention rates than angioplasty; 30-day mortality was similar. Beyond 2 years from randomisation, hazard ratios (HRs) were significantly reduced for both AFS (adjusted HR 0.37; 95% CI 0.17 to 0.77; p = 0.008) and OS (HR 0.34; 95% CI 0.17 to 0.71; p = 0.004) for surgery relative to angioplasty. By 2008 all but four patients had been followed for 3 years, some for over 7 years: 250 (56%) were dead, 168 (38%) were alive without amputation and 30 (7%) were alive with amputation. Considering the follow-up period as a whole, AFS and OS did not differ between treatments but for patients surviving beyond 2 years from randomisation, bypass was associated with reduced HRs for AFS (HR 0.85; 95% CI 0.50 to 1.07; p = 0.108) and OS (HR 0.61; 95% CI 0.50 to 0.75; p = 0.009), equating to an increase in restricted mean OS of 7.3 months (p = 0.02) and AFS of 5.9 months (p = 0.06) during the subsequent follow-up period. Vein bypasses and angioplasties performed better than prosthetic bypasses. HRQoL was non-significantly better in the surgery group; amputation was associated with a significant reduction in HRQoL. Over the first year, hospital costs for bypass were significantly higher (difference 5420 pounds; 95% CI 1547 pounds to 9294 pounds) than for angioplasty. However, by 3 and at 7 years the differences in cost between the two strategies were no longer significant. Patients randomised to surgery lived, on average, 29 days longer at an additional average cost of 2310 pounds. A 36-month perspective showed not significantly different mean quality-adjusted life times for angioplasty and surgery. The Delphi study revealed substantial disagreement between and among surgeons and radiologists on the appropriateness of bypass surgery or balloon angioplasty.

CONCLUSIONS

The findings of our study suggest that in patients with SLI due to infrainguinal disease the decision whether to perform bypass surgery or balloon angioplasty first appears to depend upon anticipated life expectancy. Patients expected to live less than 2 years should usually be offered balloon angioplasty first as it is associated with less morbidity and cost, and such patients are unlikely to enjoy the longer-term benefits of surgery. By contrast, those patients expected to live beyond 2 years should usually be offered bypass surgery first, especially where a vein is available as a conduit. Many patients who could not undergo a vein bypass would probably have been better served by a first attempt at balloon angioplasty than prosthetic bypass. The failure rate of angioplasty in SLI is high (c. 25%) and patients who underwent bypass after failed angioplasty fared significantly worse than those who underwent surgery as their first procedure. The interests of a significant proportion of BASIL patients may have been best served by primary amputation followed by high-quality rehabilitation. Further research is required to confirm or refute the BASIL findings and recommendations; validate the BASIL survival prediction model in a separate cohort of patients with SLI; examine the clinical and cost-effectiveness of new endovascular techniques and devices; and compare revascularisation with primary amputation and with best medical and nursing care in those SLI patients with the poorest survival prospects.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN45398889.

Bypass or angioplasty for severe limb ischaemia? A Delphi Consensus Study

OBJECTIVES

To examine the level of agreement among vascular surgeons and interventional radiologists regarding their preference for the surgical or endovascular management of severe limb ischaemia.

DESIGN

Delphi consensus study using 596 different hypothetical patient scenarios.

PARTICIPANTS

Delphi consensus group for the Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL) trial.

METHODS

Twenty consultant vascular surgeons and 17 interventional radiologists completed both rounds of the study. The scenarios detailed the anatomical extent of disease, whether the patients had rest pain only or had tissue loss, and whether or not a suitable vein for bypass was available. Panellists were asked to score their treatment preference for either surgery or angioplasty on an eight-point scale. Outliers (top 10% and bottom 10% responses) were removed. If the remaining 80% of responses fell within a 3-point range, this was defined as "agreement". If they did not, this was considered "disagreement".

RESULTS

There was substantial disagreement in 484 (81%) of scenarios in round 1 and 401 (67%) in round 2. This disagreement was greater among surgeon than radiologists in both round 1 (83 vs 65%) and round 2 (69 vs 42%). Surgeons also demonstrated less convergence between rounds.

CONCLUSIONS

There is substantial disagreement between and among surgeons and radiologists with regard to the appropriateness of surgery or angioplasty for severe limb ischaemia. This lack of consensus stems from the absence of an evidence base and means that the same patient may receive entirely different treatment depending on which hospital and consultant they attend. Not only may this unexplained variation be clinically unsatisfactory, it has major implications for the planning and use of health service resources.

The role of angiography in the management of haemorrhage from major fractures of the pelvis

In a series of 150 consecutive patients with unstable fractures of the pelvis, angiography was performed in 23 (15%) who had uncontrolled hypotension. There were three anteroposterior compression (APC), eight lateral compression (LC) and 12 vertical shear (VS) injuries. Arterial sources of haemorrhage were identified in 18 (78%) patients and embolisation was performed. Angiography was required in 28% of VS injuries. The morphology of the fracture was not a reliable guide to the associated vascular injury. Ten (43%) patients died, of whom six had had angiography as the first therapeutic intervention. Five of these had a fracture which was associated with an increase in pelvic volume (APC or VS) which could have been stabilised by an external fixator. Based on our findings we recommend skeletal stabilisation and, if indicated, laparotomy to deal with sources of intraperitoneal blood loss before pelvic angiography. Embolisation of pelvic arterial bleeding is a worthwhile procedure in patients with hypotension which is unresponsive to these interventions.

The role of angiography in the management of haemorrhage from major fractures of the pelvis

In a series of 150 consecutive patients with unstable fractures of the pelvis, angiography was performed in 23 (15%) who had uncontrolled hypotension. There were three anteroposterior compression (APC), eight lateral compression (LC) and 12 vertical shear (VS) injuries. Arterial sources of haemorrhage were identified in 18 (78%) patients and embolisation was performed. Angiography was required in 28% of VS injuries. The morphology of the fracture was not a reliable guide to the associated vascular injury. Ten (43%) patients died, of whom six had had angiography as the first therapeutic intervention. Five of these had a fracture which was associated with an increase in pelvic volume (APC or VS) which could have been stabilised by an external fixator. Based on our findings we recommend skeletal stabilisation and, if indicated, laparotomy to deal with sources of intraperitoneal blood loss before pelvic angiography. Embolisation of pelvic arterial bleeding is a worthwhile procedure in patients with hypotension which is unresponsive to these interventions.

Microbiological examination of cold ready-to-eat sliced meats from catering establishments in the United Kingdom

A microbiological study of cold, ready-to-eat sliced meats from 2579 catering establishments (public houses, hotels, cafés, restaurants, residential homes and other catering premises) found that 2587 of 3494 samples (74%) were of acceptable quality, 892 (26%) were of unsatisfactory quality and 15 (<1%) were of unacceptable quality. Unacceptable results were due to high levels of Escherichia coli, Staphylococcus aureus, Listeria species and/or Clostridium perfringens. Unsatisfactory results were mostly due to high Aerobic Plate Counts. The microbiological quality of cold, ready-to-eat meats was associated with meat type, premises type, management training, hygienic practices, meat supplier and length of storage. The relationship between food hygiene training and microbiological quality is discussed.

The microbiological quality of ice used to cool drinks and ready-to-eat food from retail and catering premises in the United Kingdom

A survey of 4,346 samples of ice from retail and catering premises examined 3,528 samples (81%) used to cool drinks and 144 samples (3%) from food displays. For 674 samples (15%), the origin was not recorded. Most samples of ice used to cool drinks or ready-to-eat food on displays did not contain coliforms, Escherichia coli, or enterococci. Of the ice used to cool drinks, 9% contained coliforms, 1% E. coli, and 1% enterococci in excess of 10(2) CFU/100 ml, and 11% had an aerobic plate count at 37 degrees C in excess of 10(3) CFU/ml. The microbiological quality of ice used to cool drinks was poorer when melt water was present in the ice buckets. Ice used in food displays was more contaminated than ice used to cool drinks, with 23% containing coliforms, 5% E. coli, and 8% enterococci at 10(2) CFU/100 ml or more. Twenty-nine percent of samples had an aerobic plate count greater than 10(3) CFU/ml. Ice that had been used to cool shellfish was of a lower microbiological quality than samples used to cool ready-to-eat fish, salads, or dairy produce. Samples of ice produced in commercial production facilities were of higher microbiological quality than samples of ice that were not. The microbiological quality of ice was dependent on the type of use, the type of premises, and the type and place of production. Although most ice samples were of acceptable microbiological quality, evidence from this study suggests that the microbiological quality of ice prepared and used at certain premises in the UK is a cause for concern.

Microbiological investigation of halal butchery products and butchers' premises

Halal butchers' premises were investigated as they had not been represented in a recent study of butchery products and butchers' premises conducted by the Local Authorities Coordinating Body on Food and Trading Standards and the PHLS. This study examined 183 raw prepared meats and 212 environmental samples from 105 halal butcher premises. Only raw meats were prepared on 97 of the premises visited; and the types of meat prepared on the remaining eight premises was not specified. Four halal butchers sold cooked meats prepared elsewhere. Salmonella spp. and Campylobacter spp. were detected in 12 (7%) and 52 (28%) of the 183 raw meat products, respectively. Five raw prepared meats (3%) contained both salmonella and campylobacter. Vero cytotoxin producing Escherichia coli O157 was isolated from a raw meat product that also contained campylobacter. No cooked meat products were available for collection. The physical separation of raw and unwrapped cooked meat products in premises that prepared raw and sold cooked meats was not recorded. Apron cloths were the most heavily contaminated environmental samples examined; hygiene indicator microorganisms indicated an increased risk of cross contamination. Managers in 85 premises had received no food hygiene training and 88 premises had no hazard analysis system in place. Improvements are needed to reduce the risk of cross contamination.

Vascular surgical society of great britain and ireland: percutaneous transluminal angioplasty for lower limb ischaemia

BACKGROUND: Percutaneous transluminal angioplasty (PTA) is increasingly performed for lower limb ischaemia of all severities, despite the absence of controlled data demonstrating its efficacy. The aim of this study was to examine the indications and outcome for lower limb ischaemia over a 16-year period. METHODS: A prospectively gathered database of 1287 consecutive PTAs performed between 1982 and 1997 was analysed. Two time intervals were compared: 1982-1991 and 1992-1997. RESULTS: Since 1992 there has been a fourfold increase in the number of PTAs performed. There has been a significant increase in the number of PTAs performed for critical ischaemia, occlusive lesions and at infrainguinal sites. Although there has been a significant reduction in morbidity, the number of immediate technical and clinical failures has increased (see Table ). CONCLUSION: Despite a lack of controlled data supporting a more liberal use of PTA in the treatment of lower limb ischaemia, there has been, in this regional vascular unit, a significant increase in the perceived clinical and anatomical indications for the procedure. Randomized controlled trials are urgently required to define the role of PTA in this condition.

Vascular surgical society of great britain and ireland: outcome of iliac percutaneous transluminal angioplasty with and without the use of stents in patients with intermittent claudication

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 < 0.01, chi2 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 < 0.05, chi2 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 < 0.05, chi2 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.

Comparison of colour Doppler ultrasound and digital subtraction angiography in the diagnosis of lower limb arterial disease

A fifteen-month retrospective review (December 1993 to February 1995 inclusive) was performed comparing findings at Colour Doppler Ultrasound (CDU) and Digital Subtraction Angiography (DSA) in patients with symptomatic peripheral arterial disease or post-operative by-pass grafts. The records of 63 patients (43 males and 20 females) who had undergone both CDU and DSA within three months of each other were analysed. The age range of case studied was 33-84 years (mean 64 yrs.) Disease in each arterial or graft segment was classified into five grades, 0 (normal) to 4 (complete occlusion). A total of 72 limbs were examined. Fifty-four patients had unilateral symptoms while both limbs are affected in 9 cases. In all 241 arterial and graft segments were studied. There was overall agreement between findings of CDU and DSA in 193/241 (80/1%) and non-agreement in 48/241 (19.9%). Of the 48 examinations that showed discrepancy, the findings in 26/48 (54.2%) were one grade apart while in the remaining 22/48 (45.8%) there was a difference of two or more grades. Agreement between CDU and DSA in the individual arterial segments studied was as follows: common femoral 42/48 (87.5%); profunda femoris 19/25 (76.0%); superficial femoral 27/39 (81.0%); anterior tibial 17/81 (94.4%) and peroneal 15/17 (88/2%). In the grafts, there was an agreement of 20/27 (74/1%) between CDU and DSA. These results show a good correlation between the two imaging modalities with complete agreement and agreement within one grade in 80.1% and 90.9% of cases, respectively, confirming that CDU can be employed as a useful screening technique for assessment of symptomatic patients, allowing selection of patients for angioplasty alone or angiography for arterial mapping or those who require by-pass graft surgery.

Patient dose measurements from femoral angiography

Investigation of patient dose from femoral angiography requires detailed logging of dose-area product (DAP) measurements, which is time-consuming and only possible on small numbers of patients. A simple model for the femoral angiogram study consists of two regions; lower limbs and torso. The experimental phantom was the abdominal and pelvic sections of a Rando phantom, and two 10 cm diameter water filled cylinders to represent a lower limb. DAP rate during screening, and the DAP per spot film exposure were obtained in two rooms. Total DAP values were measured on 100 patients in each room. The median screening time and number of spot film exposures were divided between the two regions. The DAP from screening and spot films for each region was estimated by combining the phantom and patient data. The total DAP predicted by the model agreed to within 7% of the median DAP from the patient studies Conversion to effective dose gave 9.0 mSv for the newer room compared with 2.8 mSv for the older room. In the newer room it was estimated that digital spot film exposure contributed 88% of the total effective dose. In the same room, exposure of the torso contributed 98% of the total effective dose. The model will enable interpretation of total DAP measurements made from femoral angiogram studies without the need for detailed DAP measurements on every patient. Attempts to reduce patient dose from femoral angiography must concentrate on reduction of the number and dose per exposure from abdominal and pelvic digital spot films.

Surveillance imaging of the operated artery does not alter clinical outcome following carotid endarterectomy

Clinical outcome was studied in 243 patients undergoing 260 carotid endarterectomies; 166 of these patients underwent serial postoperative surveillance imaging. Including perioperative events, cumulative freedom from ipsilateral stroke was 86 and 82 per cent at 5 and 10 years respectively; the mean incidence of ipsilateral stroke was 1.8 per cent per annum. Twenty patients (8 per cent) suffered cerebral ischaemic events in the hemisphere of the operated side during follow-up: eight transient ischaemic attacks (TIA) and 12 strokes (only two preceded by TIA). Two symptomatic patients were found to have occluded the operated artery but the remainder had no evidence of significant recurrent disease. Cumulative freedom from occlusion or severe (greater than 70 per cent) recurrent stenosis was 87 and 78 per cent at 5 and 10 years respectively; the mean incidence of recurrence of significant disease was 2.2 per cent per annum. No revisional surgery was performed on the operated arteries. In its current format, neither clinical nor surveillance imaging could have prevented any of the strokes observed during follow-up.

Fate of the non-operated carotid artery after contralateral endarterectomy

The long-term fate of the non-operated internal carotid artery (ICA) in 219 patients undergoing contralateral carotid endarterectomy was studied; 151 patients underwent serial postoperative imaging of the vessel. Cumulative freedom from stroke in the non-operated hemisphere was 99, 96 and 86 per cent at 1, 5 and 10 years respectively, giving a mean incidence of stroke of 1 per cent per annum. Only one stroke was preceded by a transient ischaemic attack and no stroke was associated with severe (70 per cent or greater) stenosis of the ICA. Ten patients (7 per cent) with initially mild or moderate disease of the non-operated ICA progressed to severe stenosis during follow-up, but only three became symptomatic and, in each case, the onset of symptoms preceded recognition of disease progression. The long-term risk of stroke in the non-operated ICA territory is very small. Of practical importance is that none of the observed strokes could have been prevented by postoperative surveillance of this type.

Trends in vascular surgery since the introduction of percutaneous transluminal angioplasty

Lower-limb percutaneous transluminal angioplasty (PTA) has been used increasingly over the past decade, either alone or in conjunction with arterial reconstructive surgery. However, its impact on operation rates has not been evaluated properly. Rates of vascular operations and PTAs performed per referral for peripheral arterial disease to the regional vascular service at The Royal Infirmary, Edinburgh, were calculated for the years 1986-1992. The overall rate of PTA for peripheral arterial disease increased ninefold over this period; that for critical ischaemia increased fivefold. Rates of aortic and femoral reconstruction for all peripheral arterial disease increased by 40 and 100 per cent respectively, but rates for critical ischaemia remained static. The major amputation rate rose by 47 per cent between 1986 and 1990, and thereafter reached a plateau. Increased use of PTA was not associated with a reduction in the number of vascular operations.

Prevalence of impaired cerebrovascular reserve in patients with symptomatic carotid artery disease

Cerebrovascular reserve (CVR) was studied in 104 consecutive patients with symptomatic carotid territory disease and ipsilateral internal carotid artery stenosis. Overall, 30 of 104 patients (29 per cent) had impaired CVR. The frequency of CVR impairment increased with the severity of internal carotid artery stenosis: impairment was present in none of 11 patients with stenosis of less than 50 per cent, four of 24 with stenosis of 50-69 per cent, 14 of 41 with stenosis of 70-89 per cent and 12 of 28 with stenosis of 90-99 per cent. Patients presenting with a stroke were significantly more likely to have impaired CVR than those with transient ischaemic attacks and/or amaurosis fugax (odds ratio 3.7 (95 per cent confidence interval (c.i.) 1.5-9.0)), as were those with a residual neurological deficit (odds ratio 4.3 (95 per cent c.i. 1.6-11.5)) and evidence of infarction from computed tomography (odds ratio 3.8 (95 per cent c.i. 1.6-9.4)).

Serial imaging of the carotid bifurcation and cerebrovascular reserve after carotid endarterectomy

A radioisotopic method of quantifying mean cerebral transit time was used to assess the immediate effects of carotid endarterectomy on cerebrovascular reserve (CVR) in 69 patients. In addition, serial postoperative data were acquired on CVR, clinical status and non-invasive imaging of the internal carotid arteries in 56 patients over a period of 6-48 (median 24) months. Twenty-one patients (30 per cent) had preoperative evidence of impaired CVR in the symptomatic hemisphere. Within 4 days of surgery, however, reserve had returned to normal in 17 of the 21 patients. During follow-up, four of the 56 patients developed recurrent stenosis (> 50 per cent) or occlusion of the artery operated on but only two of these had impairment of CVR and none was symptomatic. Three patients suffered recurrent transient ischaemic attacks (TIAs) but none had recurrent internal carotid artery disease or impaired CVR. One patient suffered a TIA in the territory of the non-operated artery during follow-up in association with disease progression and CVR impairment. However, the TIA preceded recognition of either of these changes. Twelve other patients had (or developed) stenosis (> 50 per cent) in the non-operated artery during follow-up but none was symptomatic or developed impairment of CVR. Although assessment of CVR provided useful information on the frequency of haemodynamic compromise before carotid endarterectomy and on the natural history of disease progression, neither serial assessment of reserve nor non-invasive imaging of the carotid bifurcation influenced clinical practice during follow-up.

Sedation and patient monitoring in vascular and interventional radiology

A postal survey of British and Irish interventional radiologists was carried out in 1991 in order to assess current practice with respect to sedation and monitoring of patients during angiography and interventional procedures. The response rate was 65%. 49% of patients are fasted prior to angiography and 68% prior to interventional procedures. Radiologists participate in obtaining consent in 60% of cases. Patients are often (50%) sedated for angiography and usually (62-94% depending on the procedure) sedated for interventional procedures. Nurses are present for most procedures, but are given the task of monitoring the patient's vital signs in only 49% of cases. Anaesthetists are present for less than 10% of interventional procedures. Pulse oximetry is used routinely in 20% of departments, and automatic blood pressure monitors in 16%. 28% of radiologists never administer oxygen to patients under sedation, whereas 4% always do. 43% of departments have a staffed recovery area. Most vascular/interventional suites are stocked with emergency drugs and 80% with a defibrillator. 28% of departments report at least one death during or shortly after a procedure during the last 10 years. 18% of interventional radiologists have taken a refresher course in cardiopulmonary resuscitation in the past year. These findings indicate a wide variation in practice and a need to standardize practice at a uniform high level.

An audit of trends and current practice of carotid endarterectomy in Edinburgh (1975-1990)

Changes in the patient population and trends in management were studied for 260 consecutive carotid endarterectomies performed during the periods 1975-1982 and 1983-1990. A 43% increase was observed in the number of operations (from 107 to 153), an 81% increase taking into account patients randomized to medical treatment in the European Carotid Surgery Trial. There were significant reductions in patients continuing to smoke (79 to 60%, P = 0.001), in those with systolic hypertension (21 to 11%, P = 0.018) and diastolic hypertension (26 to 12%, P = 0.002), and in those with asymptomatic carotid lesions (8 to 2%, P = 0.031). There were significant increases in the proportion of patients with strokes presenting with a residual neurological deficit (40 to 66%, P = 0.024), and in those with ocular symptoms (30 to 50%, P = 0.001) and with stenoses greater than 50% (58 to 71%, P = 0.018). This study suggests a trend for a higher risk population with more severe carotid disease. In the light of results of clinical trials, further evolution of patient selection is likely to occur and should be taken into account when evaluating the risk of carotid endarterectomy.

Accuracy and reproducibility of duplex ultrasonography in grading femoropopliteal stenoses

PURPOSE

The aim of this study was to determine the accuracy of Doppler waveform characteristics in grading femoropopliteal stenoses and to determine the interobserver and intraobserver reproducibility of measuring the same waveform characteristics.

METHODS

Thirty patients with isolated areas of stenosis found by arteriography were evaluated by color duplex sonography. Each patient underwent scanning by two observers on two separate occasions. Each observer was blind to the other's results. Doppler spectra were recorded in areas where color change suggested the highest velocity and also at the nearest normal proximal area. Peak systolic velocity, spectral broadening, and waveform configuration were measured at each site.

RESULTS

An increase in peak systolic velocity of more than 200% accurately predicted a 50% or greater reduction in luminal diameter on angiography (70% sensitivity, 96% specificity). The presence of spectral broadening and an abnormal waveform shape were found to correlate poorly with the degree of stenosis. Analysis of variance showed no significant difference between observers in velocity measurements (p = 0.78).

CONCLUSIONS

We conclude that although stenoses of greater than 50% can be distinguished from minor stenoses, more precise definition of the degree of narrowing is unlikely. The good repeatability of the velocity ratio makes it an excellent tool for monitoring major changes in the progression of disease.

Screening patients with claudication from femoropopliteal disease before angioplasty using Doppler colour flow imaging

Time, expense, risk and discomfort are incurred by arteriography in patients with intermittent claudication who might be candidates for percutaneous transluminal angioplasty (PTA). A valid screening technique could reduce the need for arteriography in patients found to have lesions not amenable to PTA. Agreement between Doppler colour flow imaging (DCFI) and angiography for detecting haemodynamically significant lesions is high, but DCFI may not identify lesions suitable for angioplasty. A total of 36 limbs in 30 patients were studied using DCFI before angiography. Agreement between the two methods was excellent (kappa = 0.91), and the predictive accuracy of DCFI for lesions amenable to PTA was good (kappa = 0.78, sensitivity 94 per cent, specificity 85 per cent, positive predictive value 83 per cent, negative predictive value 94 per cent, overall accuracy 89 per cent). DCFI is a useful screening process that may prevent unnecessary angiography, with consequent financial savings and clinical benefit.

The noise hazard in a large health care facility

A noise-level survey, dosimetry, and audiometric testing were conducted in a large health care facility to determine the areas with hazardous noise levels, the number of employees at risk, and the prevalence of noise-induced hearing loss (NIHL) among the exposed. Nine high-risk areas were identified, with readings of up to 110 dBA recorded. In the work force of approximately 6,000 employees, 321 were identified as exposed to potentially hazardous noise levels. Abnormal hearing patterns were observed in 59 (19%) of the 308 workers screened, with 36 cases of NIHL documented. The findings showed that noise is a serious hazard in many areas, that some cases of NIHL have developed from occupational exposure in this hospital, and that a control program is essential.

Arthrosonography of the irritable hip in childhood: a review of 1 year's experience

A retrospective study of 87 children presenting acutely with an "irritable hip" was undertaken to assess the role of arthrosonography of the hip joint. Arthrosonography detected 52 hip-joint effusions, of which 16 were aspirated and an effusion confirmed in 14 (88%). In 82 cases plain radiography was compared with arthrosonography for the detection of hip-joint effusions. Of 47 children with a positive ultrasound diagnosis, 28 (59%) showed abnormal findings on plain radiographs and, of 35 cases with negative ultrasound findings, 22 (63%) had a negative diagnosis by plain radiography. Patients with more severe clinical signs were more likely to have an ultrasonic diagnosis of an effusion (87%-100%) than those with mild clinical signs (25%). The ultrasonic measurement of the hip-joint capsule to femoral neck distance was 2.2 mm +/- 0.5 mm (mean +/- 1 SD) in normal hips and 6.3 mm +/- 1.5 mm in the joints with effusions. Our study suggests that arthrosonographically the normal capsular space is less than 3 mm and the difference between the two sides less than 2 mm. It is suggested that hip arthrosonography is a more accurate method for detecting hip-joint effusions than plain radiography; it may help select cases for hospital admission and should be performed before aspiration is attempted.