|Routine stent implantation vs. percutaneous transluminal angioplasty in femoropopliteal artery disease: a meta-analysis of randomized controlled trials
|Kasapis C, Henke P K, Chetcuti S J, Koenig G C, Rectenwald J E, Krishnamurthy V N, Grossman P M, Gurm H S
This review concluded that, compared with percutaneous transluminal angioplasty, routine stenting therapy was associated with a higher rate of immediate success in patients with symptomatic superficial femoral-popliteal artery disease, but no significant reduction in the rate of restenosis or target vessel revascularisation. This conclusion is likely to be reliable.
To compare the effectiveness of routine stent implantation with percutaneous transluminal angioplasty in the treatment of symptomatic superficial femoral-popliteal artery disease.
The following databases were searched from 1960 to October 2007: MEDLINE, EMBASE, ISI Web of Knowledge, Current Contents, International Pharmaceutical Abstracts databases and the Cochrane Central Register of Controlled Trials. The search terms were reported. The reference lists of retrieved publications were screened. Conference proceedings of the American Heart Association, the American College of Cardiology, the European Society of Cardiology and the Transcatheter Cardiovascular Therapeutics were also searched for 2006 and 2007. Relevant publications and internet-based sources of information were also reviewed. Manufacturing companies were contacted for unpublished data.
Randomised controlled trials (RCTs) which compared routine stenting with percutaneous transluminal angioplasty in patients with symptomatic superficial femoral-popliteal artery disease, defined using recognised criteria, were eligible for inclusion. Only trials with at least six-month outcomes were eligible for inclusion. The primary outcomes were immediate technical success or failure, restenosis and target vessel revascularisation. Secondary outcomes were mortality, post-procedural ankle-brachial index, amputations, vascular complications, early thrombo-embolic complications and bleeding or haematomas.
All RCTs permitted concomitant therapy with aspirin, whilst a number of them also allowed the use of other antithrombotic agents. Included RCTs used the following stents: nitinol, Plamaz stainless steel, tantalum and nitinol-covered stent grafts.
The authors did not state how the papers were selected for the review, or how many reviewers performed the selection.
Assessment of study quality
The quality of studies was assessed using the Jadad scale, a five-point scale evaluating randomisation, blinding, withdrawal and allocation concealment. Studies scoring ≥3 points were classified as high quality.
The authors did not state how the validity assessment was performed, or how many reviewers performed the validity assessment.
Data on the outcomes of interest were extracted in standard forms. Dichotomous outcomes were extracted into 2x2 tables. Intention-to-treat data were extracted where possible.
Two reviewers independently extracted the data from trials, with any disagreements resolved by discussion. Trial authors were also contacted for resolving discrepancies in interpreting the reported data.
Methods of synthesis
Pooled risk ratios with 95% confidence intervals (CIs) were calculated using random-effects models. It was unclear which method was used to weight trials in these meta-analyses. Statistical heterogeneity was investigated using Cochran's Q-test.
Sensitivity analyses were conducted to assess the effect of individual studies on the summary estimate. Publication bias was assessed using funnel plots and Orwin fail-safe N analysis. Meta-regression was performed to assess the effect of lesion length on the possible benefit of stenting.
Results of the review
Ten RCTs (n=1,343 patients) were included in meta-analyses. The follow-up duration ranged from nine to 24 months. Five of RCTs were judged as high quality using the Jadad score.
When the trials were pooled, a significantly higher rate of immediate technical failure was associated with percutaneous transluminal angioplasty compared with routine stenting (risk ratio 0.28, 95% CI: 0.15, 0.54, p<0.001, eight RCTs). A trend towards reduced rate of restenosis during follow-up was observed in the routine stenting group, but this was not statistically significant. There was no statistically significant difference in the rate of target vessel revascularisation within nine to 24 months between the two groups.
Statistically significant heterogeneity was observed in the outcomes of immediate technical failure (p=0.027) and restenosis (p=0.019). Sensitivity analysis did not materially affect the results. No evidence of publication bias was found according to the funnel plot or the Orwin fail-safe N analysis. Meta-regression suggested that stenting may be beneficial in longer lesions.
Subgroup analyses assessing the effect of different types of stents were reported. Additional outcomes including mortality, amputation rate, vascular complications, early thrombo-embolic events and bleeding complications were also reported.
Compared with percutaneous transluminal angioplasty, routine stenting therapy was associated with a higher rate of immediate success in patients with symptomatic superficial femoral-popliteal artery disease, but no significant reduction in the rate of restenosis and target vessel revascularisation.
The review's inclusion criteria were clear. Several relevant databases were searched. Efforts were made to find published and unpublished studies to minimise the potential of publication bias. Publication bias was further evaluated and little evidence of it was found. The authors did not state whether language restrictions were applied in the search, which made it difficult to assess the risk of language bias. Steps were taken to minimise bias by having more than one reviewer undertake the data extraction, but it was unclear whether the processes of study selection and validity assessment were also performed in duplicate. Adequate details of the primary trials were provided and relevant criteria were used to examine the study quality. Appropriate statistical methods were used to pool the results. Statistical heterogeneity was assessed and, although significant statistical heterogeneity was found in the outcomes, the trials generally showed the same direction of treatment effects. This review was generally well conducted and the authors' conclusions are likely to be reliable.
Implications of the review for practice and research
Practice: The authors stated that percutaneous transluminal angioplasty with provisional stenting should remain the preferred endovascular therapy for patients with symptomatic superficial femoral-popliteal artery disease.
Research: The authors stated that large and high quality RCTs are required to evaluate the effects of primary stenting in the treatment of symptomatic superficial femoral-popliteal artery disease.
Kasapis C, Henke P K, Chetcuti S J, Koenig G C, Rectenwald J E, Krishnamurthy V N, Grossman P M, Gurm H S. Routine stent implantation vs. percutaneous transluminal angioplasty in femoropopliteal artery disease: a meta-analysis of randomized controlled trials European Heart Journal 2009; 30(1): 44-55
Other publications of related interest
Muradin GS, Bosch JL, Stijnen T, et al. Balloon dilation and stent implantation for treatment of femoropopliteal arterial disease: meta-analysis. Radiology 2001;221:137-45.
Subject indexing assigned by NLM
Aged; Angioplasty, Balloon; Blood Vessel Prosthesis Implantation; Female; Femoral Artery; Follow-Up Studies; Humans; Male; Middle Aged; Peripheral Vascular Diseases /surgery /therapy; Popliteal Artery; Randomized Controlled Trials as Topic; Recurrence; Risk; Stents; Treatment Outcome
Database entry date
This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.