Jonathan Michaels

Systematic review of recent evidence for the safety and efficacy of elective endovascular repair in the management of infrarenal abdominal aortic aneurysm

Conventional management of abdominal aortic aneurysm (AAA) is by open repair and is associated with a mortality rate of 2–6 per cent. Endovascular aneurysm repair (EVAR) is an alternative technique first introduced in 1991. A systematic review was undertaken of the evidence for the safety and efficacy of elective EVAR in the management of asymptomatic infrarenal AAA.

Randomized controlled trial and cost-effectiveness analysis of silver-donating antimicrobial dressings for venous leg ulcers (VULCAN trial)

Antimicrobial silver dressings are used beneath graduated compression in the treatment of venous ulceration. There is little information on whether their use is effective. This was a prospective randomized trial and cost‐effectiveness analysis of silver‐donating versus non‐silver low‐adherence dressings in the treatment of venous leg ulcers.

Randomized clinical trial comparing surgery with conservative treatment for uncomplicated varicose veins.

Surgical treatment of medically uncomplicated varicose veins is common, but its clinical effectiveness remains uncertain.

Diagnosis and management of lower limb peripheral arterial disease: summary of NICE guidance

Lower limb peripheral arterial disease (referred to as peripheral arterial disease in this summary) is common, affecting 3% to 7% of people in the general population and 20% of people over the age of 75.1 It is associated with an increased risk of cardiovascular morbidity and mortality and severely limits people’s functional capacity and quality of life. Peripheral arterial disease is often asymptomatic, but when it is symptomatic the most common presentation is intermittent claudication (pain in the legs, buttocks, or thighs brought on by walking and relieved by rest). Critical limb ischaemia is characterised by severely diminished circulation, ischaemic pain, ulceration, tissue loss, and/or gangrene. Owing to rapid changes in diagnostic methods, endovascular treatments, and vascular services, there is considerable uncertainty about the management of people with peripheral arterial disease, with management varying greatly across England and Wales.2 This article summarises some of the most recent recommendations from the National Institute for Health and Clinical Excellence (NICE) on the management of peripheral arterial disease.3 NICE recommendations are based on systematic reviews of the best available evidence and explicit consideration of cost effectiveness. When minimal evidence is available, recommendations are based on the Guideline Development Group’s experience and opinion of what constitutes good practice. Evidence levels for the recommendations are given in italic in square brackets. ### Secondary prevention of cardiovascular disease in people with peripheral arterial disease

Systematic review of the efficacy of cilostazol, naftidrofuryl oxalate and pentoxifylline for the treatment of intermittent claudication

A systematic review and network meta‐analysis was undertaken to consider the evidence for the efficacy and tolerability of placebo, cilostazol, naftidrofuryl oxalate and pentoxifylline in patients with intermittent claudication due to peripheral arterial disease (PAD).

Cost-effectiveness of endovascular abdominal aortic aneurysm repair.

The rapid introduction of endovascular abdominal aortic aneurysm repair (EVAR) has considerable implications for the management of abdominal aortic aneurysm (AAA). This study was undertaken to determine an optimal strategy for the use of EVAR based on the best currently available evidence.

A systematic review of compression hosiery for uncomplicated varicose veins

Objective Compression hosiery is widely used in the prevention and management of symptoms related to varicose veins. However, there are still gaps and questions in relation to its benefit. This review seeks to examine the current evidence regarding the effectiveness of compression hosiery in the treatment of varicose veins. Method Prospective, randomized controlled trials (RCTs) evaluating compression hosiery in the treatment of varicose veins were sought. Where RCTs were unavailable other evidence was included. Studies were included if they evaluated the application of compression to patients with a diagnosis of varicose veins. Twelve electronic bibliographic databases and 18 internet-based research resources were searched. Inclusion or exclusion of trials was decided by two reviewers acting independently. Results The search strategy identified 25 studies. Eleven were RCTs or systematic reviews, 12 non-randomized studies and two guidelines. No consensus was found regarding the class of compression needed for the effective management of varicose veins. Wearing compression improved symptom management, but could be confounded by the exclusion of high number of non-compliant patients within the trials. Wearing compression to slow the progression, or prevent the reoccurrence of varicose veins could not be supported by the current published evidence. Conclusion The evidence for the benefit of compression hosiery for varicose veins was equivocal. The published literature was often contradictory and had methodological flaws.

A Systematic Review and Economic Evaluation of Cilostazol, Naftidrofuryl Oxalate, Pentoxifylline and Inositol Nicotinate for the Treatment of Intermittent Claudication in People with Peripheral Arterial Disease

BACKGROUND Peripheral arterial disease (PAD) is a condition in which there is blockage or narrowing of the arteries that carry blood to the legs and arms. It is estimated to affect around 4.5% of people aged between 55 and 74 years within the UK. The most common symptom of PAD is intermittent claudication (IC), characterised by pain in the legs on walking that is relieved with rest. OBJECTIVE To assess the effectiveness and cost-effectiveness of cilostazol, naftidrofuryl oxalate, pentoxifylline and inositol nicotinate, compared with no vasoactive drugs, for IC due to PAD in adults whose symptoms continue despite a period of conventional management. DATA SOURCE Electronic bibliographic databases were searched during April to June 2010 (MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, The Cochrane Library databases, Cumulative Index to Nursing and Allied Health Literature, Web of Science, Conference Proceedings Citation Index, BIOSIS Previews). REVIEW METHODS Effectiveness outcomes sought were maximal walking distance (MWD), pain-free walking distance (PFWD), ankle-brachial pressure index, cardiovascular events, mortality, adverse events (AEs) and health-related quality of life (HRQoL). A narrative synthesis was provided for all outcomes and a network meta-analysis was undertaken for the walking distance outcomes. A Markov model was developed to assess the relative cost-effectiveness of the interventions from a NHS perspective over a lifetime. The model has three states: vasoactive drug treatment, no vasoactive drug treatment and death. Each 1-week cycle, patients may continue with the drug, discontinue the drug or die. Regression analysis was undertaken to model the relationship between MWD and utility so that a cost per quality-adjusted life-year (QALY) outcome measure could be presented. Univariate and probabilistic sensitivity analyses were undertaken. All costs and outcomes were discounted at 3.5%. RESULTS Twenty-six randomised controlled trials were identified that met the inclusion criteria for the clinical effectiveness review. There was evidence that walking distance outcomes were significantly improved by both cilostazol and naftidrofuryl oxalate; the 95% credible intervals for the difference from placebo in the logarithm mean change MWD from baseline were 0.108 to 0.337 and 0.181 to 0.762, respectively. It was not possible to include inositol nicotinate within the meta-analysis of MWD and PFWD owing to the lack of 24-month data; however, the shorter-term data did not suggest a significant effect. AEs were minor for all drugs and included headaches and gastrointestinal difficulties. The incidence of serious adverse events (SAEs), including cardiovascular events and mortality, was not increased by the vasoactive drugs compared with placebo; however, most studies had a relatively short follow-up time to address this outcome. HRQoL data were limited. Two studies of limited quality were identified within the review of cost-effectiveness. The de novo model developed suggests that naftidrofuryl oxalate dominates cilostazol and pentoxifylline and has a cost per QALY gained of around £6070 compared with no vasoactive drug. This result is reasonably robust to changes within the key model assumptions. Inositol nicotinate was not included within the main analysis owing to lack of data. However, it is unlikely to be considered to be cost-effective due to its high acquisition cost (£900 vs £100-500 per year for the other drugs). CONCLUSIONS Naftidrofuryl oxalate and cilostazol both appear to be effective treatments for this patient population, with minimal SAEs. However, naftidrofuryl oxalate is the only treatment that is likely to be considered cost-effective. The long-term effectiveness is uncertain and hence a trial comparing cilostazol, naftidrofuryl oxalate and placebo beyond 24 weeks would be beneficial. Outcomes associated with naftidrofuryl oxalate could also be compared with those associated with supervised exercise programmes and angioplasty.

A prospective randomised controlled trial and economic modelling of antimicrobial silver dressings versus non-adherent control dressings for venous leg ulcers: the VULCAN trial.

OBJECTIVE To examine the effectiveness and cost-effectiveness of antimicrobial silver-donating dressings for venous leg ulcers compared with simple non-adherent (also known as low-adherent) dressings. DESIGN A pragmatic, prospective randomised controlled trial (RCT) and cost-effectiveness analysis of silver-donating versus low-adherent dressings in the treatment of venous leg ulcers. A non-randomised observational group was also recruited. SETTING Primary and secondary care services in the north and south of England (Sheffield and Exeter). PARTICIPANTS Consenting patients with active ulceration of the lower leg that had been present for a period of greater than 6 weeks. INTERVENTIONS Patients were randomised to receive either a silver-donating or non-silver low-adherent dressing applied beneath compression bandages or hosiery. The choice of dressing within these groups was left to clinician preference. Evaluation was by clinical assessment, supplemented by evaluation of quality of life and cost-effectiveness. MAIN OUTCOME MEASURES The primary outcome measure was complete ulcer healing at 12 weeks in the index limb. Secondary measures were costs and quality-adjusted life-years (QALYs), cost-effectiveness, time to healing, and recurrence rate at 6 months and 1 year. RESULTS In total, 304 participants were recruited to the clinical trial: 213 to the RCT and 91 to the observational arm. Within the RCT 107 were randomised to antimicrobial dressings and 106 to the control dressings. There were no significant differences (p > 0.05) between the two groups for the primary outcome measure of proportion of ulcers healed at 12 weeks (59.6% for silver and 56.7% for control dressings). The overall median time to healing was also not significantly different between the two groups (p = 0.408). A total of 24 patients had recurrent ulcers within 1 year; the recurrence rates of 11.6% (n = 11) for the antimicrobial and 14.4% (n = 13) for the control dressings were not significant. Mean utility valuations for both the EuroQol 5 dimensions (EQ-5D) quality of life questionnaire and Short Form 6 dimensions (SF-6D) utility index showed no differences for either group at 1, 3, 6 or 12 months. Compared with the control group, the antimicrobial group had an incremental cost of 97.85 pounds and an incremental QALY gain of 0.0002, giving an incremental cost-effectiveness ratio for the antimicrobial dressings of 489,250 pounds. Cost-effectiveness modelling of the results of the RCT showed that antimicrobial dressings were not cost-effective. CONCLUSIONS No significant differences in either primary or secondary end points were found between the use of antimicrobial silver-donating dressings and the control group of low-adherent dressings. Modelling showed that antimicrobial silver dressings were not cost-effective. TRIAL REGISTRATION Current Controlled Trials ISRCTN72485131.

A systematic review of compression therapy for venous leg ulcers

The aim of the study was to determine the relative effectiveness of compression therapies used in the treatment of venous leg ulcers. Randomized controlled trials (RCT) were sought using a search strategy that aimed to identify relevant RCT by searching eight electronic databases (including Medline, Embase and CINHAL), conference proceedings and hand searching key journals. In addition, citations within papers were scrutinized to identify any relevant studies. Suitability for inclusion in this review was determined by a critical appraisal of key determinants of the quality of the trials. Trials that included patients of mixed ulcer aetiology were excluded unless the results of patients with venous disease were reported separately. Data was extracted independently by two reviewers and synthesized quantitatively and qualitatively. Losses to follow-up/withdrawals were assumed to be failures of treatment. A total of 132 articles were identified, and of these eight fulfilled the inclusion criteria. The remaining 126 trials were excluded due to trial design flaws, the inclusion of mixed/arterial aetiology ulcers or because they were non-RCT. Meta-analysis using a random-effects model showed the benefits of multi-layer and elastic compression bandages. It was concluded that more high-quality trials are required and that more emphasis should be placed on economic and quality of life data to try to ascertain the cost-effectiveness and utility of the treatment options available.