Twenty-nine studies (n=2,286) were included in the review. Three were RCTs (n=234) and 26 were non-RCTs (n=2052). Two of the RCTs were of moderate to good quality, but the other was poor. Most of the non-RCTs used consecutive recruitment. Only five described how the surgical strategy was selected (a further nine reported this in part). Five studies addressed potential confounding, but none adjusted the results statistically for differences in important prognostic patient characteristics.
Of the 15 trials comparing one-stage with two- or three-stage procedures the mortality rates in eight were consistently in favour of one-stage surgery (up to a 27 per cent reduction), although only two actually reported a statistically significant difference between the procedures. Six studies reported similar results between the two groups. Only one study reported results favouring two- or three-stage procedures. There was no significant effect on perioperative morbidity rates (9 trials).
Of the studies comparing two- with three-stage procedures, one RCT showed no difference in mortality and four favoured a three-stage procedure. Of the eight studies comparing stenting with no stenting, all non-RCTs favoured stenting for mortality; the one RCT reported no deaths in both groups. Data on morbidity were inconsistent.