ORCID Profile
0000-0002-6159-2340
Current Organisation
Flinders Medical Centre
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Publisher: SAGE Publications
Date: 08-10-2014
Abstract: To assess the efficacy of the ClariVein® system of mechanico-chemical ablation of superficial vein incompetence. ClariVein® treatment uses a micropuncture technique and a 4-Fr sheath to allow a catheter to be placed 1.5 cm from the saphenofemoral junction. Unlike laser (endovenous laser treatment (EVLT)) or radiofrequency ablation (RFA), no tumescence is required. The technique depends on a wire rotating at 3500 r/min causing endothelial damage whilst liquid sclerosant (1.5% sodium tetradecyl sulphate) is infused. The wire is pulled back whilst continuously infusing sclerosant along the target vessel’s length. Initially, 8 mL of dilute sclerosant was used, but this was subsequently increased to 12 mL. No routine post-op analgesia was prescribed and specifically no non-steroidal anti-inflammatory drugs. Procedure times and pain scores (visual analogue scale) were recorded and compared to EVLT and RFA. All patients were invited for duplex post-procedure. Fifty-one great saphenous veins and six short saphenous veins were treated and followed up with duplex in the 10 months from July 2011. No major complications or deep vein thrombosis were reported. Duplex showed patency of three treated veins with two more veins having only a short length of occlusion, giving a technical success rate of 91%. Comparison with 50 RFA and 40 EVLT showed procedure times were significantly less for ClariVein® (23.0 ± 8.3 min) than for either RFA (37.9 ± 8.3 min) or EVLT (44.1 ± 11.4 min). Median pain scores were significantly lower for ClariVein® than RFA and EVLT (1 vs. 5 vs. 6, p 0.01). Mechanochemical ablation with the ClariVein® system is safe and effective. After some initial failures, the use of 12 mL of dilute sclerosant results in a very high technical success rate % which accords with the limited published literature. Procedure times and pain scores are significantly better than for RFA and EVLT. We await the long-term clinical outcomes.
Publisher: SAGE Publications
Date: 12-2009
Abstract: Endovascular aneurysm repair (EVAR) of ruptured abdominal aortic aneurysm (rAAA) has been shown to be both feasible and associated with a reduced operative mortality when compared with conventional open repair (OR). The aim of this study was to show the feasibility of EVAR of rAAA in a rural vascular unit and to investigate the blood product requirements when compared to OR. The method used in this study was a retrospective case note review of patients presenting with rAAA to a small, rural vascular unit between February 2004 and November 2008. Admission demographics and hematological variables were recorded. Volumes of crystalloid, colloid and blood products were recorded prior to intensive care unit (ICU) admission and for the first 48 hours following ICU admission. Results are expressed as medians and Mann-Whitney U test was used to compare variables. Of 81 patients presenting with rAAA, 36 were treated palliatively. Of 45 patients who underwent intervention, 7 had EVAR and all survived to discharge (0% operative mortality). Of 38 who had OR, 16 died before discharge for an operative mortality of 42%, 36% if the EVAR patients are included. Admission demographics and hematological variables of patients who had EVAR, patients who had OR and survived (ORS) and patients who had OR and died (ORD) showed no significant difference. When compared with ORS patients, those undergoing EVAR had significantly less pre-ICU crystalloid (3 L vs 7.5 L, p = .001), less red blood cell transfusion (1 unit vs 6.5 units, p = .0006), and less colloid (0 L vs 0.5 L, p = .008). When compared with ORD, those undergoing EVAR had less red blood cell transfusion (1 unit vs 7 units, p = .0001) and less fresh frozen plasma (0 units vs 4 units, p = .03). Within the first 48 hours of admission to ICU, the blood product requirements were no different in those undergoing EVAR when compared with OR. EVAR of rAAA is feasible in a small rural vascular unit and appears to be associated with reduced requirements for blood products.
Publisher: MDPI AG
Date: 14-09-2016
DOI: 10.3390/HEALTHCARE4030069
Abstract: Oxidative stress (OS) and inflammatory processes initiate the first stage of cardiovascular disease (CVD). Flavonoid consumption has been related to significantly improved flow-mediated dilation and blood pressure. Antioxidant and anti-inflammatory mechanisms are thought to be involved. The effect of flavonoids on markers of oxidative stress and inflammation, in at risk in iduals is yet to be reviewed. Systematic literature searches were conducted in MEDLINE, Cochrane Library, CINAHL and SCOPUS databases. Randomised controlled trials in a Western country providing a food-based flavonoid intervention to participants with one or two modifiable risk factors for CVD measuring a marker of OS and/or inflammation, were included. Reference lists were hand-searched. The Cochrane Collaboration Risk of Bias Tool was used to assess study quality. The search strategy retrieved 1248 articles. Nineteen articles meeting the inclusion criteria were reviewed. Eight studies were considered at low risk of bias. Cocoa flavonoids provided to Type 2 diabetics and olive oil flavonoids to mildly-hypertensive women reduced OS and inflammation. Other food sources had weaker effects. No consistent effect on OS and inflammation across patients with varied CVD risk factors was observed. Study heterogeneity posed a challenge for inter-study comparisons. Rigorously designed studies will assist in determining the effectiveness of flavonoid interventions for reducing OS and inflammation in patients at risk of CVD.
Publisher: Wiley
Date: 14-03-2018
DOI: 10.1111/ANS.14441
Abstract: Lower gastrointestinal bleeding (LGIB) is a common acute general surgical condition that is typically self-limiting however in refractory cases it can necessitate life-saving intervention. When bleeding is refractory, super-selective embolization (SSE) becomes an important management strategy. This study aims to evaluate outcomes of this procedure at our institution and identify predictors of clinical success. A retrospective analysis of patients with positive computed tomography angiograms for LGIB at a tertiary centre between December 2007 and May 2017. Of 87 600 acute general surgical admissions, 2700 were for LGIB. Computed tomography angiography demonstrated active bleeding in 104 patients who then had mesenteric angiograms. SSE was performed in 77 patients of whom 66 (86%) demonstrated active bleeding. Technical success was achieved in 75 patients (97%). Clinical success was achieved in 63 patients (81%). Re-bleeding occurred in 14 patients (19%), with four requiring surgery. One patient went forward for re-embolization. Bowel ischaemia occurred in four patients (5.2%), with two requiring bowel resection. A 30-day mortality following SSE was 6.5%, with one death attributable to bowel ischaemia and four deaths from medical comorbidity. Median age (years) of those who had clinical success was 78 (interquartile range (IQR) 16.4) and those who did not was 65 (IQR 20.2) (P = 0.031). Clinical success was more common in those who had erticular related bleeding (61.9%) compared to other pathologies (38.1%) (P = 0.036). SSE was successful in a high proportion of patients in this series with low complication rates. Clinical success was higher in those who were older or with erticular related bleeding.
Publisher: Elsevier BV
Date: 12-2016
DOI: 10.1016/J.JVS.2016.06.099
Abstract: Supervised exercise is currently recommended for the first-line treatment of intermittent claudication based on improvement in walking capacity. However, the promotion of skeletal muscle atrophy by repetitive ischemia-reperfusion caused by treadmill-based programs remains a concern. Because preservation of skeletal muscle mass (SMM) and lean mass (LM) is integral to functional capacity and longevity, this study measured the effect of standard treadmill-based supervised exercise on SMM and regional lower limb LM in patients with intermittent claudication. Patients with calf claudication caused by infrainguinal peripheral artery disease underwent whole-body dual-energy X-ray absorptiometry scanning before and after completion of a 12-week supervised treadmill exercise program. Total body SMM and lower limb LM were measured according to anatomical regions of the lower limb (thigh vs calf) and side of symptoms. Walking performance was assessed using pain-free walking distance and 6-minute walking distance tests. Thirty-six patients with calf claudication completed exercise training and dual-energy X-ray absorptiometry scanning, allowing analysis of 55 symptomatic and 17 asymptomatic lower limbs. No difference in total body SMM (P = .41) or LM of symptomatic (P = .53) or asymptomatic calves (P = .59) was detected after the program. In contrast, a significant decrease in LM was observed in symptomatic (P = .04) and asymptomatic thighs (P = .005). Pain-free walking distance (P = .001) and the 6-minute walking distance both improved significantly (P = .004) but were not associated with changes in LM. Twelve weeks of standard treadmill-training for intermittent calf claudication did not result in loss of calf LM however, a significant decrease in bilateral thigh LM was observed, even in patients with unilateral symptoms. Further research on optimum exercise modalities and end points are required to determine the pathophysiology and effects of these changes on function and survival.
Publisher: Hindawi Limited
Date: 2016
DOI: 10.1155/2016/2969740
Abstract: This study compared flow-mediated dilatation (FMD), peripheral artery tonometry (PAT), and serum nitric oxide (NO) measures of endothelial function in patients with peripheral artery disease (PAD) against age/gender matched controls. 25 patients (mean age: 72.4 years, M : F 18 : 7) with established PAD and an age/gender matched group of 25 healthy controls (mean age: 72.4 years, M : F 18 : 7) were studied. Endothelial function was measured using the % FMD, reactive hyperemia index (RHI) using PAT and serum NO ( μ mol). Difference for each method between PAD and control patients and correlation between the methods were investigated. FMD and RHI were lower in patients with PAD (median FMD for PAD = 2.16% versus control = 3.77%, p = 0.034 and median RHI in PAD = 1.64 versus control = 1.92, p = 0.005 ). NO levels were not significantly different between the groups (PAD median = 7.70 μ mol, control median = 13.05 μ mol, p = 0.662 ). These results were obtained in elderly patients and cannot be extrapolated to younger in iduals. FMD and PAT both demonstrated a lower hyperaemic response in patients with PAD however, FMD results in PAD patients were unequivocally reduced whereas half the PAD patients had RHI values above the established threshold for endothelial dysfunction. This suggests that FMD is a more appropriate method for the measurement of NO-mediated endothelial function.
No related grants have been discovered for Simon Vun.