This generally well-conducted review assessed the outcomes of subintimal angioplasty for the treatment of peripheral arterial occlusive disease and concluded that the procedure may be useful for wound healing and limb salvage in the treatment of critical limb ischaemia. Given the observational nature of the included studies, the findings should be interpreted with caution.

To assess the outcomes of subintimal angioplasty for the treatment of peripheral arterial occlusive disease.

MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, National Guideline Clearinghouse, TRIP database, Bandolier and British Medical Journal Clinical Evidence were searched to May 2007 without language restrictions. Search terms were reported.

Clinical studies comprising an original series of at least 10 patients receiving subintimal angioplasty for the treatment of femoral, popliteal or crural occlusion were eligible for inclusion. Those reporting a maximum of five per cent iliac occlusions were also included. Studies had to report technical success (good antegrade flow at procedure completion) and, at one year, primary patency assessed through an established imaging technique or limb salvage. Complications and survival were also assessed.

Mean or median patient age ranged between 59 to 81 years. Included studies comprised varying proportions of patients with diabetes (9% to 72%), hypertension (26% to 83%) and smokers (15% to 95%). Lesions were reported as being located in the crural, femoral, popliteal, femoropopliteal, iliac and infrainguinal arteries. Clinical grade of disease comprised critical limb ischaemia, intermittent claudication or a mixture of both.

Two reviewers independently screened studies for selection, with disagreements resolved by discussion or, where necessary, through consultation with a third reviewer.

Two independent reviewers assessed the studies for validity using criteria based on the Dutch Cochrane Collaboration checklist describing: patient selection and characteristics; description of the lesion and techniques; completeness of follow-up; objective assessment of patency; and patient outcome. For inclusion, studies had to describe in detail certain criteria (patient characteristics, description of the lesion and techniques that were assessed and definition of outcome). The maximum possible score was 14.

The authors did not state how disagreements were resolved.

Data for a list of pre-specified outcomes were extracted as percentages.

Two reviewers independently performed the data extraction. Disagreements were resolved by discussion or, where necessary, through consultation with a third reviewer.

A narrative synthesis was provided, supported by tables, with differences between studies discussed in the text. Study outcomes were grouped by the clinical grade of disease and location of lesion.

Twenty three studies were included in the review (n=1,549, range 27 to 148 patients): 11 retrospective studies; eight prospective studies; and four in which study design was unclear. Mean or median duration of follow-up was between three and 41 months. Study quality scores ranged from 8 to 14: two studies scored 8; and the remaining 21 scored 11 or more.

Technical success rates (23 studies) were mostly between 80 per cent and 90 per cent. Lower rates of success were reported for lesions in crural vessels for critical limb ischaemia patients and lower rates of success were reported for femoral or femoropopliteal lesions when intermittent claudication was assessed. Clinical success (nine studies) ranged between 56 per cent and 69 per cent for critical limb ischaemia patients and 50 per cent to 68 per cent for critical limb ischaemia and intermittent claudication patients. Primary (16 studies) and primary assisted patency (four studies) rates varied across studies from 22 per cent to 87 per cent. For limb salvage (13 studies), all studies reported rates over 80 per cent, except for one where it was 66 per cent. At one year, survival was between 50 per cent to 87 per cent in patients with critical limb ischaemia and 85 per cent to 100 per cent in patients with critical limb ischaemia and intermittent claudication. Complication rates (19 studies) ranged from two per cent to 20 per cent. The most frequently reported events included haematoma of the groin, perforation of the artery and distal embolism.

Subintimal angioplasty may be useful for peripheral arterial occlusive disease, particularly so for wound healing and limb salvage in the treatment of critical limb ischaemia.

The review question and inclusion criteria were clear. A thorough search for studies with no language restrictions was undertaken, which reduced the likelihood of language bias. There was no apparent search for unpublished studies, therefore, some studies may have been missed. All stages of the review process were undertaken in duplicate, reducing the potential for error and bias. Appropriate criteria were used to assess the quality of the included observational studies, which were generally of reasonable quality. Given the heterogeneity between the studies, the decision to employ a narrative synthesis was appropriate. Although this was a generally well-conducted review, and the authors' conclusions reflected the available evidence, limitations in study design for the included studies suggest that these findings should be interpreted with caution.

Practice: The authors did not state implications for practice.

Research: The authors stated that studies of greater methodological quality should comprise cohorts of patients admitted for critical limb ischaemia, rather than selected patients. Future studies should adhere to standards for reporting results of treatment for peripheral arterial disease, especially for lower-extremity arterial endovascular procedures.

Not stated.

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.