Contrast-induced nephropathy (CIN) is a well-recognized complication of radiographic contrast adm... more Contrast-induced nephropathy (CIN) is a well-recognized complication of radiographic contrast administration and is the third leading cause of hospital-acquired renal insufficiency. The use of contrast media is increasing, particularly in the area of endovascular therapy. Vascular interventionists need to be aware of strategies to reduce the risk of CIN. Numerous trials, meta-analyses, and expert guidelines for the prevention of CIN have been published between 1966 and 2006, but the majority of studies have been conducted on patients undergoing coronary interventions; few have involved vascular surgical population. The literature suggests that adequate hydration is essential in all patients due to receive contrast. No pharmacological agents have been shown to conclusively reduce the risk. Forced diuresis is harmful, and there is insufficient evidence to support routine use of hemodialysis or hemofiltration. Well conducted studies of other potential prophylactic techniques are needed in vascular populations.
International Journal of Clinical Practice, Nov 21, 2007
Peri-operative fluid therapy is a controversial area with few randomised trials to guide practice... more Peri-operative fluid therapy is a controversial area with few randomised trials to guide practice. Recently, a number of trials have suggested that intra-operative therapy guided by oesophageal Doppler acquired haemodynamic variables may improve postoperative outcome. Abstract databases and conference proceedings were searched to identify randomised controlled trials comparing Doppler-guided intra-operative fluid management to standard practice in patients undergoing major abdominal surgery. Pooled odds ratios (POR) and weighted mean differences (WMD) were calculated for categorical and continuous outcomes respectively. Four trials, comprising 393 patients, were identified. Use of an oesophageal Doppler-guided fluid management algorithm resulted in fewer postoperative complications (POR 0.32; 95% CI: 0.19-0.52; p < 0.0001) and shorter hospital stays (WMD 1.68 days; 95% CI: 2.39-0.98; p < 0.0001). There were no significant differences in the quantities of intra-operative fluids administered although there was some evidence of heterogeneity with respect to this outcome. Oesophageal Doppler-guided fluid management may improve outcome following major intra-abdominal surgery. However, comparison with fluid restriction strategies, including a cost-effectiveness analysis are required.
To determine whether local anaesthetic infiltration of the long saphenous tunnel in patients unde... more To determine whether local anaesthetic infiltration of the long saphenous tunnel in patients undergoing unilateral, primary long saphenous stripping and multiple avulsions reduces early postoperative pain and requirement for opiate analgesia. Patients were randomized to receive either levobupivicaine or an equivalent volume of normal saline infiltrated around the groin incision and along the long saphenous tunnel. Analgesia and linear analogue pain scores at 1, 6 and 24h postoperatively were recorded. Fourteen patients received local anaesthetic and 13 patients received saline placebo. The anaesthetic group experienced a 22% reduction in pain scores 1 h postoperatively and a 48% reduction at 6 h although this failed to achieve statistical significance. However, the anaesthetic group were less likely to require morphine in recovery (2/14 [14%] versus 8/13 [62%]; P = 0.01). The high morphine requirements in the control group may have reduced the amount of pain those patients recorded on their pain scores and prevented statistical significance from being achieved. In varicose vein surgery, local anaesthetic infiltration to the groin wound and along the full length of the stripper track is associated with reduced postoperative pain and requirements for opiate analgesia.
Introduction Ankle-brachial pressure indices (ABIs) continue to form the basis of diagnostics for... more Introduction Ankle-brachial pressure indices (ABIs) continue to form the basis of diagnostics for lower extremity arterial disease (LEAD). However, there remains a paucity of data to support its accuracy. This study aims to evaluate its diagnostic sensitivity and specificity using established arterial-imaging modalities as a benchmark. Methods In this retrospective study, a regional, prospectively maintained, vascular laboratory database was interrogated to identify referred patients with arterial disease who underwent concomitant assessment with ABI and lower limb arterial duplex ultrasound (DUS). Duplex acted as the reference standard. Those who had peripheral computed tomography angiogram (CTA) within 3 months of initial assessment were included in a subgroup analysis to correlate ABI with CTA. The primary end point was the sensitivity and specificity of ABI compared with DUS as the reference standard. Results Concomitant assessment was performed in 438 limbs (250 patients) over ...
Background Endovenous treatment of varicose veins has increased in popularity over the last decad... more Background Endovenous treatment of varicose veins has increased in popularity over the last decade. There remains, however, a degree of uncertainty regarding the role of compression bandaging or hosiery following this intervention. The National Institute for Clinical Excellence Guideline Development Group has advocated further research to evaluate the clinical and cost-effectiveness of this post-procedure intervention. In addition to this, the duration of compression bandaging also warrants clarification. Methods Ethical approval for the study was obtained from the Singhealth Centralised Institutional Review Board (CIRB Ref: 2017/2710). Consent to enter the study will be sought from each participant only after a full explanation has been given, an information leaflet offered and time allowed for consideration. Signed participant consent will be obtained. Patients will be randomised to either compression (group A) or no compression (group B). The primary aim of the study is to assess...
Background: Venous leg ulceration is a widespread, debilitating pathology with high recurrence ra... more Background: Venous leg ulceration is a widespread, debilitating pathology with high recurrence rates. Conservative treatment using graduated compression dressings may be associated with unacceptable ulcer recurrence rates. Early superficial venous ablation encourages ulcer healing and reduces recurrence. However, many of this cohort display concomitant ilio-caval stenosis, which further contributes to lower limb venous hypertension and ulceration. An approach which combines early superficial venous ablation with early treatment of ilio-caval stenotic disease may significantly improve ulcer healing and recurrence rates. We question whether early iliac vein interrogation with intravascular ultrasound (IVUS), stenting of significant occlusive disease plus superficial venous ablation, in patients with active venous leg ulceration, will produce superior ulcer healing to standard therapy. Methods: This is a prospective, multi-centre, randomised controlled, feasibility trial recruiting pat...
Background: Venous leg ulceration is a widespread, debilitating pathology with high recurrence ra... more Background: Venous leg ulceration is a widespread, debilitating pathology with high recurrence rates. Conservative treatment using graduated compression dressings may be associated with unacceptable ulcer recurrence rates. Early superficial venous ablation encourages ulcer healing and reduces recurrence. However, many of this cohort display concomitant ilio-caval stenosis, which further contributes to lower limb venous hypertension and ulceration. An approach which combines early superficial venous ablation with early treatment of ilio-caval stenotic disease may significantly improve ulcer healing and recurrence rates. We question whether early iliac vein interrogation with intravascular ultrasound (IVUS), stenting of significant occlusive disease plus superficial venous ablation, in patients with active venous leg ulceration, will produce superior ulcer healing to standard therapy. Methods: This is a prospective, multi-centre, randomised controlled, feasibility study recruiting pat...
Ultrasonography is increasingly used by clinicians to identify abdominal aortic aneurysms (AAA). ... more Ultrasonography is increasingly used by clinicians to identify abdominal aortic aneurysms (AAA). We performed a systematic review and meta-analysis comparing the accuracy of non-radiologist performed ultrasound (NRPUS) for AAA disease to the 'gold standard' of radiologist performed aortic imaging (RPI), intra-operative findings or postmortem findings. Cochrane Library, MEDLINE, EMBASE, SCOPUS-V.4, trial registries, conference proceedings, and article reference lists were searched to identify studies comparing NRPUS with RPI as the reference standard. Data abstracted from eligible studies was used to generate 2 × 2 contingency tables allowing calculation of pooled sensitivity and specificity values. 11 studies (944 patients) evaluated NRPUS for AAA detection. NRPUS had a pooled sensitivity of 0.975 [95% confidence interval (CI), 0.942-0.992] for AAA detection and a pooled specificity of 0.989 (95% CI, 0.979-0.995). Non-radiologist performed ultrasound achieves acceptable sens...
Contrast-induced nephropathy (CIN) is a well-recognized complication of radiographic contrast adm... more Contrast-induced nephropathy (CIN) is a well-recognized complication of radiographic contrast administration and is the third leading cause of hospital-acquired renal insufficiency. The use of contrast media is increasing, particularly in the area of endovascular therapy. Vascular interventionists need to be aware of strategies to reduce the risk of CIN. Numerous trials, meta-analyses, and expert guidelines for the prevention of CIN have been published between 1966 and 2006, but the majority of studies have been conducted on patients undergoing coronary interventions; few have involved vascular surgical population. The literature suggests that adequate hydration is essential in all patients due to receive contrast. No pharmacological agents have been shown to conclusively reduce the risk. Forced diuresis is harmful, and there is insufficient evidence to support routine use of hemodialysis or hemofiltration. Well conducted studies of other potential prophylactic techniques are needed in vascular populations.
International Journal of Clinical Practice, Nov 21, 2007
Peri-operative fluid therapy is a controversial area with few randomised trials to guide practice... more Peri-operative fluid therapy is a controversial area with few randomised trials to guide practice. Recently, a number of trials have suggested that intra-operative therapy guided by oesophageal Doppler acquired haemodynamic variables may improve postoperative outcome. Abstract databases and conference proceedings were searched to identify randomised controlled trials comparing Doppler-guided intra-operative fluid management to standard practice in patients undergoing major abdominal surgery. Pooled odds ratios (POR) and weighted mean differences (WMD) were calculated for categorical and continuous outcomes respectively. Four trials, comprising 393 patients, were identified. Use of an oesophageal Doppler-guided fluid management algorithm resulted in fewer postoperative complications (POR 0.32; 95% CI: 0.19-0.52; p < 0.0001) and shorter hospital stays (WMD 1.68 days; 95% CI: 2.39-0.98; p < 0.0001). There were no significant differences in the quantities of intra-operative fluids administered although there was some evidence of heterogeneity with respect to this outcome. Oesophageal Doppler-guided fluid management may improve outcome following major intra-abdominal surgery. However, comparison with fluid restriction strategies, including a cost-effectiveness analysis are required.
To determine whether local anaesthetic infiltration of the long saphenous tunnel in patients unde... more To determine whether local anaesthetic infiltration of the long saphenous tunnel in patients undergoing unilateral, primary long saphenous stripping and multiple avulsions reduces early postoperative pain and requirement for opiate analgesia. Patients were randomized to receive either levobupivicaine or an equivalent volume of normal saline infiltrated around the groin incision and along the long saphenous tunnel. Analgesia and linear analogue pain scores at 1, 6 and 24h postoperatively were recorded. Fourteen patients received local anaesthetic and 13 patients received saline placebo. The anaesthetic group experienced a 22% reduction in pain scores 1 h postoperatively and a 48% reduction at 6 h although this failed to achieve statistical significance. However, the anaesthetic group were less likely to require morphine in recovery (2/14 [14%] versus 8/13 [62%]; P = 0.01). The high morphine requirements in the control group may have reduced the amount of pain those patients recorded on their pain scores and prevented statistical significance from being achieved. In varicose vein surgery, local anaesthetic infiltration to the groin wound and along the full length of the stripper track is associated with reduced postoperative pain and requirements for opiate analgesia.
Introduction Ankle-brachial pressure indices (ABIs) continue to form the basis of diagnostics for... more Introduction Ankle-brachial pressure indices (ABIs) continue to form the basis of diagnostics for lower extremity arterial disease (LEAD). However, there remains a paucity of data to support its accuracy. This study aims to evaluate its diagnostic sensitivity and specificity using established arterial-imaging modalities as a benchmark. Methods In this retrospective study, a regional, prospectively maintained, vascular laboratory database was interrogated to identify referred patients with arterial disease who underwent concomitant assessment with ABI and lower limb arterial duplex ultrasound (DUS). Duplex acted as the reference standard. Those who had peripheral computed tomography angiogram (CTA) within 3 months of initial assessment were included in a subgroup analysis to correlate ABI with CTA. The primary end point was the sensitivity and specificity of ABI compared with DUS as the reference standard. Results Concomitant assessment was performed in 438 limbs (250 patients) over ...
Background Endovenous treatment of varicose veins has increased in popularity over the last decad... more Background Endovenous treatment of varicose veins has increased in popularity over the last decade. There remains, however, a degree of uncertainty regarding the role of compression bandaging or hosiery following this intervention. The National Institute for Clinical Excellence Guideline Development Group has advocated further research to evaluate the clinical and cost-effectiveness of this post-procedure intervention. In addition to this, the duration of compression bandaging also warrants clarification. Methods Ethical approval for the study was obtained from the Singhealth Centralised Institutional Review Board (CIRB Ref: 2017/2710). Consent to enter the study will be sought from each participant only after a full explanation has been given, an information leaflet offered and time allowed for consideration. Signed participant consent will be obtained. Patients will be randomised to either compression (group A) or no compression (group B). The primary aim of the study is to assess...
Background: Venous leg ulceration is a widespread, debilitating pathology with high recurrence ra... more Background: Venous leg ulceration is a widespread, debilitating pathology with high recurrence rates. Conservative treatment using graduated compression dressings may be associated with unacceptable ulcer recurrence rates. Early superficial venous ablation encourages ulcer healing and reduces recurrence. However, many of this cohort display concomitant ilio-caval stenosis, which further contributes to lower limb venous hypertension and ulceration. An approach which combines early superficial venous ablation with early treatment of ilio-caval stenotic disease may significantly improve ulcer healing and recurrence rates. We question whether early iliac vein interrogation with intravascular ultrasound (IVUS), stenting of significant occlusive disease plus superficial venous ablation, in patients with active venous leg ulceration, will produce superior ulcer healing to standard therapy. Methods: This is a prospective, multi-centre, randomised controlled, feasibility trial recruiting pat...
Background: Venous leg ulceration is a widespread, debilitating pathology with high recurrence ra... more Background: Venous leg ulceration is a widespread, debilitating pathology with high recurrence rates. Conservative treatment using graduated compression dressings may be associated with unacceptable ulcer recurrence rates. Early superficial venous ablation encourages ulcer healing and reduces recurrence. However, many of this cohort display concomitant ilio-caval stenosis, which further contributes to lower limb venous hypertension and ulceration. An approach which combines early superficial venous ablation with early treatment of ilio-caval stenotic disease may significantly improve ulcer healing and recurrence rates. We question whether early iliac vein interrogation with intravascular ultrasound (IVUS), stenting of significant occlusive disease plus superficial venous ablation, in patients with active venous leg ulceration, will produce superior ulcer healing to standard therapy. Methods: This is a prospective, multi-centre, randomised controlled, feasibility study recruiting pat...
Ultrasonography is increasingly used by clinicians to identify abdominal aortic aneurysms (AAA). ... more Ultrasonography is increasingly used by clinicians to identify abdominal aortic aneurysms (AAA). We performed a systematic review and meta-analysis comparing the accuracy of non-radiologist performed ultrasound (NRPUS) for AAA disease to the 'gold standard' of radiologist performed aortic imaging (RPI), intra-operative findings or postmortem findings. Cochrane Library, MEDLINE, EMBASE, SCOPUS-V.4, trial registries, conference proceedings, and article reference lists were searched to identify studies comparing NRPUS with RPI as the reference standard. Data abstracted from eligible studies was used to generate 2 × 2 contingency tables allowing calculation of pooled sensitivity and specificity values. 11 studies (944 patients) evaluated NRPUS for AAA detection. NRPUS had a pooled sensitivity of 0.975 [95% confidence interval (CI), 0.942-0.992] for AAA detection and a pooled specificity of 0.989 (95% CI, 0.979-0.995). Non-radiologist performed ultrasound achieves acceptable sens...
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Papers by Stewart Walsh