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The Ordovician-aged Lawn Hill Impact Structure is perhaps unique among documented craters, in that it is largely filled with slumped, allochthonous Cambrian carbonates partly fluidised by the impact shock. It is a complex geological feature, with a thin horizon of suevite beneath carbonate sheets. The bulk of the impact ejecta material was either deposited on top of the mobilised carbonates, and not preserved owing to erosion, or is present beneath the base of current drilling. The geometry of the crater in its final form has been modelled in three dimensions using gravity data and dipole–dipole-induced polarisation geophysics, with control from an extensive drill-hole library. Post-impact modification, including terrace formation and carbonate fill, has resulted in an asymmetric ring syncline, which extends to depths >600 m. In the data-rich area of the Century zinc–lead–silver deposit, on the southwest margin of the crater, both intact and remnants of the crater rim and impact ejecta blanket were preserved above the deposit. The Proterozoic ore deposit is located on a detached terrace, which slumped into the crater and was buried by allochthonous carbonates from the Georgina basin. The sequence of events can be shown to comprise: impact with crater formation and injection of carbonate dykes and inter-thrust wedges in the crater walls with concurrent suevite deposits inside and surge deposits outside the crater; this was rapidly followed by slumping of carbonate mega-blocks transported by a fluidised carbonate slurry into the crater, concomitant with collapse of Proterozoic terraces; finally, collapse of the central crater uplift generated imbricate slices of Cambrian carbonate among mainly Proterozoic rocks inside the ring syncline. After impact, the Ordovician-aged Lawn Hill Impact Structure crater was filled with slumped terraces of Proterozoic sediments and Pb–Zn ore, fluidised Cambrian carbonate, plus mega-clasts of both of those, on top of a thin but persistent hematitic suevite. Outside the crater, remnants of base surge and debris deposits represent the ejecta blanket. The Century Zn–Pb deposit was preserved on a disrupted terrace; the crater rim was partially preserved above the deposit and the mineralised sequence truncated by the crater wall. Geophysical and drilling data show a terraced, asymmetric ring syncline, up to at least 600 m thick in places. [ABSTRACT FROM AUTHOR]

The article presents a randomized clinical study which aims to determine the radiological, clinical and patient-based results of conventional surgery and radiofrequency ablation (RFA) treatments of great saphenous varicose veins. The study collected and compared data from consecutive patients aged from 18 to 70 years with symptomatic varicose veins who were randomized to undergo RFA and conventional surgery. Results show that RFA treatment works better compared to conventional surgery.

Currently, monitoring of blood glucose level (BGL) is constrained by the invasive nature of BGL measures. We investigated heart rate variability (HRV) parameters as potential non-invasive markers of BGL. Healthy volunteers (n = 25; aged 27 ± 9 years) uninhibited by regular medications or chronic illness were recruited for this study. BGL and HRV were assessed during fasting (9:00 am), postprandial (12:00 pm), and postabsorptive (3:00 pm) periods using self-monitoring of blood glucose techniques and ten-minute electrocardiogram, respectively. Frequency-domain HRV measures, which estimate contributions of sympathetic and parasympathetic systems to autonomic modulation of the heart, were correlated against BGL data with the following significant (p < 0.05) findings. The change in BGL from fasting to postprandial levels was negatively correlated with fasting low frequency (LF) power and total power (TP). Postprandial BGL was negatively associated with fasting LF and TP, as well as with postprandial LF, high frequency (HF), and TP. The change in BGL from postprandial to postabsorptive levels was positively correlated with fasting LF power, as well as with postprandial LF, HF, and TP. Frequency-domain HRV parameters may be useful in predicting the magnitude and direction of acute fluctuations in BGL, and further research could develop them as non-invasive markers of BGL. [ABSTRACT FROM AUTHOR]

The article offers information on the launch of the Venous Intervention (VEIN) Project in Great Britain. It says that the project was designed to define how health services should be provided and the way the intervention should be delivered for patients with symptomatic, uncomplicated varicose veins. Moreover, it notes that the project focuses on patients with uncomplicated varicose veins and is expected to provide support for patients.

Objectives: Since 2009 the National Health Service (NHS) has been collecting patient- reported outcome measures (PROMs) following varicose vein interventions. The objective of this manuscript was to interrogate the one-year PROMs data with respect to varicose vein intervention and to discuss its potential impact on the provision of service. Methods: We interrogated the one-year PROMs data with respect to potential impact on the provision of service. Results: In total, 37,521 varicose vein operations were performed during the study period (1April 2009-30 April 2010). A total of 15,808 preoperative questionnaires were completed and returned and 12,509 were linked to Hospital Episode Statistics episodes. A total of 8127 postoperative questionnaires were completed and linked to the preoperative questionnaires. For the EuroQuol (EQ) 5D questionnaire average preoperative score across the completed data-set was 0.773. The postoperative health gain was 0.094. Fifty-three percent of patients had improved postoperative scores, 33% reported no change, while 14% reported a reduction in their postoperative EQ-5D score. Pain/discomfort was the only domain where patients reported any negative symptoms; 72% (5390) reported pain/ discomfort preoperatively and 37% (2804) postoperatively. In total, 62.6% (4685) reported no pain/discomfort following surgery A total of 7167 complete, linked and eligible data- sets were observed for the Aberdeen Varicose Vein Questionnaire (AVVQ). The average preoperative score was 18.75. The average postoperative score was 10.76. This represented a reduction in symptom scores of one-half following intervention. The lowest improvements were witnessed in patients with the lowest preoperative scores (least severe symptoms). Additional postoperative questions highlighted the improvements conferred from varicose vein surgery with 90.3% of patients reporting an improvement in their problems from varicose veins following surgery and 85% describing their operative results as excellent, very good or good. Conclusion: These data have shown variable improvements following venous interventions. PROMs are likely to have significant implications for health care in the NHS on a number of levels including provision of funding and future planning of services. [ABSTRACT FROM AUTHOR]

Background: A coding framework was evaluated to study patients undergoing open surgical replacement of an abdominal aortic aneurysm (AAA) in the English Hospital Episode Statistics (HES) database. The objective was to create groups of patients who are homogeneous with respect to diagnosis, prognosis and treatment. Methods: The frequency and consistency of potentially relevant diagnosis (International Classification of Diseases, 10th revision) and procedure (Office of Population Censuses and Surveys Classification, 4th revision) codes were assessed in patients admitted to English National Health Service hospitals between April 2003 and March 2008. Administrative codes were compared with diagnosis and procedure codes to check that patients who had undergone emergency surgery for a ruptured AAA were admitted as an emergency. Results: Of 20 290 patients undergoing AAA replacement, 19 250 (94·9 per cent) had a consistent diagnosis (unruptured or ruptured AAA); 79·3 per cent of patients with an emergency replacement were coded as having a ruptured AAA and 95·7 per cent of those with a non-emergency replacement as having an unruptured AAA. Of patients who had undergone emergency replacement of a ruptured AAA, 93·3 per cent were coded as having been admitted as an emergency. Conclusion: Coding consistency was high. The proposed framework could define homogeneous groups by combining diagnosis, procedure and administrative codes. It also allows an assessment of potential miscoding at national and hospital level. Copyright © 2011 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Background The Abdominal Aortic Aneurysm ( AAA) Screening Programme was introduced by the National Health Service ( NHS) in England to reduce the rate of death from ruptured AAA in men. The programme commenced in 2009 and was implemented completely across the country in April 2013. The aim was to review the first 5 years of the programme, looking specifically at compliance and early outcome. Methods Men aged 65 years were invited for a single abdominal ultrasound scan. Data were entered into a bespoke database ( AAA SMaRT). This was a planned analysis after the first 5 years of the programme. Results The summation analysis involved the first 700 000 men screened, and the first 1000 men with a large AAA referred for possible treatment. The prevalence of AAA (aortic diameter larger than 2·9 cm) in 65-year-old men was 1·34 per cent. Mean uptake was 78·1 per cent, but varied from 61·7 to 85·8 per cent across the country. Based on the Index of Multiple Deprivation, uptake was 65·1 per cent in the most deprived versus 84·1 per cent in the least deprived areas. Of the first 1000 men referred for possible treatment of a large AAA (greater than 5·4 cm), the false-positive rate was 3·2 per cent. Some 870 men underwent a planned AAA intervention (non-intervention rate 9·2 per cent), with seven deaths (perioperative mortality rate 0·8 per cent). Conclusion The processes in the NHS AAA Screening Programme are effective in detecting and treating men with AAA. [ABSTRACT FROM AUTHOR]

National Confidential Enquiry into Patient Outcome and Death guidelines for urgent surgery recommend a fully staffed emergency operating theatre and restriction of ‘after-midnight’ operating to immediate life-, limb- or organ-threatening conditions. Audit performed in our institution demonstrated significant decreases in waiting times for urgent surgery and an increased seniority of medical care associated with overnight pre-operative assessment of patients by anaesthetic trainees. Nevertheless, urgent cases continued to be delayed unnecessarily. A classification of delays was developed from existing guidelines and their incidence was audited. The results were disseminated to involved directorates. A repeat of the audit demonstrated a significant decrease in delays (p = 0.001), a significant increase in the availability of surgeons (p = 0.001) and a significant decrease in the median waiting time for urgent surgery compared to the first audit cycle and a previous standard (p < 0.01). We conclude that auditing delays and disseminating the results of the audit significantly decreases delays and median waiting times for urgent surgery because of improved surgical availability. [ABSTRACT FROM AUTHOR]

The effectiveness of some novel software tools used for clustering and classifying multivariate data is tested and used to evaluate mineral exploration criteria by examining a mineral deposit and major fault database. The database containing 364 diverse mineral deposits is divided into natural groups utilising a vector quantisation data-mining approach based on a self-organising map (SOM), and phenetic and cladistic analysis packages. The last two approaches are loosely based on biological principles of numerical taxonomy and evolutionary relationships, respectively. Based on the assumption of a common process of formation, the analyses are used to define the group (or class) of Archean orogenic-gold deposits, as distinct from gold deposit types such as turbidite-hosted orogenic gold, Carlin-type, and porphyry Cu - Au that should be excluded from this group. The main findings from this study are: (i) large, global-scale databases, representing the full range of commodity types, geographic locations, ages and variation in deposit characteristics, are required in order to classify new deposit examples using these techniques; (ii) traditional classifications are broadly correct but inadequately define deposit types; and (iii) SOM, and phenetic and cladistic analysis packages can aid in the identification of the characteristics (i.e. commodity, rock type, alteration, vein morphology, fluid composition) of the deposits that are mainly responsible for defining individual deposit groups. Applied to metallogenic terranes that host many different styles of mineralisation and deposit groups (such as Archean cratons), this approach can aid in identifying which deposits belong to a single coherent group. Analysis of the major fault database in this pilot study emphasises the need to obtain a significantly larger number of entries (total of 138 entries used, whereas >>200 entries are required). It also highlights the impact of incomplete attribute data and the categorical nature of many of the datafields that describe faults. Nevertheless, preliminary results of several statistical analyses (Boolean, SOM, phenetic, cladistic) of the major fault database confirm the importance of empirically derived criteria for mineralisation, such as proximity to crustal-scale faults and anticlinal hinge zones, dilational jogs and fault roughness, strong rheological contrasts at lithological boundaries and metamorphic grade. Presence and concurrence of these parameters determine the extent of metallogenic endowment of a given fault system and segments within it. [ABSTRACT FROM AUTHOR]

Background: Vascular Biochemistry and Haematology Outcome Models (VBHOM) adopted the approach of using a minimum data set to model outcome. This study aimed to test such a model on a cohort of patients undergoing open elective and non-elective abdominal aortic aneurysm (AAA) repair. Methods: A binary logistic regression model of risk of in-hospital mortality was built from the 2002-2004 submission to the UK National Vascular Database (NVD) (2718 patients). The subset of NVD data items used comprised serum levels of urea, sodium and potassium, haemoglobin, white cell count, sex, age and mode of admission. The model was applied prospectively using Hosmer-Lemeshow methodology to a test data set from the Cambridge Vascular Unit. Results: The validation set contained 327 patients, of whom 208 had elective AAA repair and 119 had emergency repair of a ruptured AAA. Outcome following elective and non-elective AAA repair could be described accurately using the same model. The overall mean predicted risk of death was 14.13 per cent, and 48 deaths were predicted. The actual number of deaths was 53 (X² = 8.40, 10 d.f., P = 0.590; no evidence of lack of fit). The model also demonstrated good discrimination (c-index = 0.852). Conclusion: The VBHOM approach has the advantage of using simple, objective clinical data that are easy to collect routinely. The VBHOM data items potentially allow prediction of risk in an individual patient before aneurysm surgery. [ABSTRACT FROM AUTHOR]

Discusses the abstract of a study evaluating the midterm results of a Vanguard endovascular device for the repair of an abdominal aortic aneurysm. Mortality rate; Implant success rate; Survival rate.

Investigates the effectiveness of surgical and radiological intervention of vascular disease. Different types of the combined procedure performed; Need for coordination between surgeons and radiologist; Reasons for the failure of the combined operation.

A response by D. R. Prytherch, T. Y. Tang, S. R. Walsh, T. Lees, K. Varty and J. R. Boyle on their article about VBHOM, a data economic model for predicting the outcome after open abdominal aortic aneurysm surgery, is presented.

Reports the immediate and long-term outcomes from an experience of endovascular abdominal aortic stent graft repair (EVR). Treatment of patients with EVR; Measurement of cumulative survival probabilities; Association of EVR with acceptable early outcome and late survival.