Treatment effectiveness of angioplasty versus stenting in atherosclerotic disease of the iliac arteries

Background

Atherosclerosis in the iliac artery (main pelvic artery towards the leg) may result in narrowing or obstruction (occlusion), leading to reduced blood flow to the leg. This is called iliac artery occlusive disease. Iliac artery occlusive disease may lead to symptoms of pain in the legs at walking (intermittent claudication), pain at rest, or even ulcers of the foot or leg. A range of surgical and endovascular (from inside the artery, e.g. angioplasty) treatment options are available. Open surgical procedures have excellent patency rates (percentage of the vessels that remain open) but at the cost of substantial illness and death. Endovascular treatment has good safety and short-term effectiveness with decreased illness, complications and costs compared with open surgical procedures. Percutaneous transluminal angioplasty (PTA; dilation of the artery with a balloon) and stenting (insertion of a small mesh tube) are widely used endovascular treatment options for iliac artery occlusive disease. A narrowing or obstruction of the iliac artery can be treated successfully by PTA alone. If PTA alone is not successful, an additional stent can be placed. Alternatively, a stent could be placed on its own to treat an iliac narrowing or obstruction (this is called primary stenting). However, there is limited evidence to prove which endovascular treatment strategy is better for stenotic and occlusive lesions of the iliac arteries. This review investigates whether it is better to place a stent primarily, or only on specific indications.

Key results

We identified only two studies with a combined total of 397 participants relevant to this topic. Combining of data was not possible due to the differences between the two included studies. We could not demonstrate that either of the two strategies was superior to the other. Five of the pre-planned outcomes were not reported in either study (improvement in walking distance as reported by the patient, measured claudication distance, ulcer healing, major amputation-free survival (survival without above-ankle amputation), delayed complications (more than 72 hours)). In most other pre-planned outcomes no differences were shown between the treatments (improvement in the stage of the classification of the severity of the arterial occlusive disease, resolution of symptoms and signs, improvement of quality of life, technical success of the procedure, patency of the treated vessel). However, in one study, which only included iliac artery occlusions, fewer complications were observed in the group of participants that were treated with primary stenting. The other study showed a slightly higher ankle brachial index (blood pressure in the leg compared to blood pressure in the arm, higher is better) at two years after the procedure, but not at other time points. This difference might not be clinically relevant. More research is necessary on this subject.

Quality of the evidence

Both studies had some risk of bias relating to selective reporting and non-blinding of participants and personnel. We consider the overall quality of the evidence to be low due to the small number of included studies, the differences in the types of patients that were included and the way outcomes were reported.

Authors' conclusions: 

There is insufficient evidence to assess the effects of PTA versus PS for stenotic and occlusive lesions of the iliac artery. From one study it appears that PS in iliac artery occlusions may result in lower distal embolisation rates. More studies are required to come to a firm conclusion.

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Background: 

Atherosclerosis of the iliac artery may result in a stenosis or occlusion, which is defined as iliac artery occlusive disease. A range of surgical and endovascular treatment options are available. Open surgical procedures have excellent patency rates but at the cost of substantial morbidity and mortality. Endovascular treatment has good safety and short-term efficacy with decreased morbidity, complications and costs compared with open surgical procedures. Both percutaneous transluminal angioplasty (PTA) and stenting are commonly used endovascular treatment options for iliac artery occlusive disease. A stenotic or occlusive lesion of the iliac artery can be treated successfully by PTA alone. If PTA alone is technically unsuccessful, additional stent placement is indicated. Alternatively, a stent could be placed primarily to treat an iliac artery stenosis or occlusion (primary stenting, PS). However, there is limited evidence to prove which endovascular treatment strategy is superior for stenotic and occlusive lesions of the iliac arteries.

Objectives: 

To assess the effects of percutaneous transluminal angioplasty versus primary stenting for stenotic and occlusive lesions of the iliac artery.

Search strategy: 

The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched April 2015) and Cochrane Register of Studies (CRS) (2015, Issue 3). The TSC searched trial databases for details of ongoing and unpublished studies.

Selection criteria: 

We included all randomised controlled trials (RCTs) comparing percutaneous transluminal angioplasty and primary stenting for iliac artery occlusive disease. We excluded quasi-randomised trials, case reports, case-control or cohort studies. We excluded no studies based on the language of publication.

Data collection and analysis: 

Two authors (JB, NA) independently selected suitable trials. JB and HJ independently performed data extraction and trial quality assessment. When there was disagreement, consensus would be reached first by discussion among both authors and, if still no consensus could be reached, through consultation with BF.

Main results: 

We identified two RCTs with a combined total of 397 participants as meeting the selection criteria. One study included mostly stenotic lesions (95%), whereas the second study included only iliac artery occlusions. Both studies were of moderate methodological quality with some risk of bias relating to selective reporting and non-blinding of participants and personnel. The overall quality of evidence was low due to the small number of included studies, the differences in study populations and definitions of the outcome variables. Due to the heterogeneity among these two studies it was not possible to pool the data. Percutaneous transluminal angioplasty (PTA) with selective stenting and primary stenting (PS) resulted in similar improvement in the stage of peripheral arterial occlusive disease according to Rutherford's criteria, resolution of symptoms and signs, improvement of quality of life, technical success of the procedure and patency of the treated vessel. Improvement in walking distance as reported by the patient, measured claudication distance, ulcer healing, major amputation-free survival and delayed complications (> 72 hours) were not reported in either of the studies. In one trial, PTA of iliac artery occlusions resulted in a significantly higher rate of major complications, especially distal embolisation. The other trial showed a significantly higher mean ankle brachial index (ABI) at two years in the PTA group (1.0) compared to the mean ABI in the PS group (0.91); mean difference (MD) 0.09 (95% confidence interval (CI) 0.04 to 0.14; P value = 0.001, analysis performed by review authors). However, at other time points there was no difference. We consider it unlikely that this difference is attributable to the study procedure, and also believe this difference may not be clinically relevant.

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