Angioplasty versus stenting for superficial femoral artery lesions
Abstract
This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:
The primary aim will be to determine the most efficacious treatment for TASC A and B superficial femoral artery stenoses in patients with symptomatic (Fontaine stages II to IV) (Fontaine 1954) lower limb peripheral vascular disease.
In addition, where data exist, the efficacy of angioplasty and stenting in improving quality of life, ankle brachial pressure index and treadmill walking distance will be assessed. Uncommon percutaneous interventions such as atherectomy will not be considered.
Background
Description of the condition
Lower limb peripheral arterial disease (PAD) is a common, important manifestation of systemic atherosclerosis. It occurs in 3% to 10% of the population, increasing to 15% to 20% in people over 70 years of age (Selvin 2004). The most common site of PAD is the superficial femoral artery (SFA) (Fowkes 1991). While most patients with PAD are asymptomatic, many have intermittent claudication, chronic critical limb ischaemia or acute critical limb ischaemia. As a result, PAD significantly impairs quality of life and is the most common cause of lower limb amputation in the western world. The prognosis for PAD patients following amputation is dismal, with a 70% overall two‐year survival and a 40% return to full mobility (Dormandy 1994).
Description of the intervention
Successful treatment of PAD is therefore of the utmost importance. Superficial femoral artery disease may be treated by a number of modalities depending on the length of lesion. For lesions less than 10 cm long in symptomatic patients, the most common treatment is currently percutaneous transluminal angioplasty (PTA) with or without the use of stents. Exercise therapy and operative intervention are also possible. While PTA can result in initial technical success rates of more than 95%, late clinical failure remains an important concern.
Why it is important to do this review
The recognition that treatment for PAD varied by centre has led to the creation of continually updated international guidelines (Norgen 2007). These guidelines currently recommend the use of PTA as a primary treatment in SFA lesions less than 10 cm long with stenting for acute primary failure. However, recent randomised control trials have results conflicting with these recommendations and in some cases, one another (Schllinger 2006; Zdanowski 1999).
Objectives
The primary aim will be to determine the most efficacious treatment for TASC A and B superficial femoral artery stenoses in patients with symptomatic (Fontaine stages II to IV) (Fontaine 1954) lower limb peripheral vascular disease.
In addition, where data exist, the efficacy of angioplasty and stenting in improving quality of life, ankle brachial pressure index and treadmill walking distance will be assessed. Uncommon percutaneous interventions such as atherectomy will not be considered.
Methods
Criteria for considering studies for this review
Types of studies
All randomised control trials of percutaneous angioplasty with or without stenting (of any type) will be included.
Types of participants
All patients with intermittent claudication or critical ischaemia (Fontaine stages II to IV) will be included.
Types of interventions
The angioplasty or stent insertion must be performed percutaneously or though a limited groin incision. The treatment must be primary unless angioplasty failed and stenting was then performed as part of the primary procedure. Antiplatelet therapy preceding and following intervention will be noted. Data will be stratified for whether the interventions tested were performed for claudication or critical limb ischaemia.
Types of outcome measures
Primary outcomes
-
Rates of restenosis (in trials with at least six months follow up and using techniques directly imaging the treatment site).
-
Clinical outcome.
Secondary outcomes
-
Ankle brachial pressure index.
-
Quality of life (by validated questionnaire only).
-
Treadmill walking distance (both absolute and initial claudication distance).
Search methods for identification of studies
The Cochrane Peripheral Vascular Diseases (PVD) Group will search their trials register and the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library for publications describing randomised controlled trials (RCTs) of percutaneous angioplasty with or without stenting. The PVD Group's trials register is compiled from ongoing electronic searches of MEDLINE (1966 to date), EMBASE (1980 to date), and CINAHL (1982 to date), and through handsearching relevant journals. The full list of journals that have been handsearched, as well as the search strategies used are described in the 'Search strategies for the identification of studies' section within the editorial information about the Cochrane PVD Group in The Cochrane Library.
In addition, we will run searches in PUBMED and bibliographies of papers found through these searches will be examined to identify further trials. There will be no restriction on language of publication.
Data collection and analysis
Selection of trials
Two authors (CT and JC) will independently select trials for inclusion, extract data, assess trial quality and analyse results. Disagreements will be resolved by ADM.
Quality of trials
The methodological quality of trials will be assessed independently by each review author using the checklist provided by the PVD Group, with emphasis on concealment of allocation. Any disagreements will be resolved by discussion.
Data extraction
Two authors (CT and JC) will extract assess and code data independently using a pro‐forma designed specifically for the review. Any disagreement will be resolved by discussion. Any additional information required will be obtained from trial authors. Data will be cross‐checked by AS and ADM. Data will be entered into RevMan by one author (CT) and cross checked by two authors (JC and ADM).
Statistical analysis
Statistical analysis will follow the standard method of the Cochrane PVD Group. All analysis will be based on endpoint data from the individual clinical trials. Publication bias will be tested using the funnel plot. Appropriate corrective analytical methods will be attempted depending on the number of trials included in the review. Data will be evaluated for overall freedom from procedures performed on the contralateral leg.
