A Cochrane review included 10 studies with a total of 1 967 subjects undergoing 2 157 operations. Follow up varied from hospital discharge to 5 years. Carotid patch angioplasty was associated with a reduction in the risk of ipsilateral stroke during the perioperative period (OR 0.31, 95% CI 0.15 to 0.63, 7 studies, n=1201) and long-term follow up (OR 0.32, 95% CI 0.16 to 0.63, 6 studies, n=1141). It was also associated with a reduced risk of perioperative arterial occlusion (OR 0.18, 95% CI 0.08 to 0.41, 7 studies, n= 1435), and decreased restenosis during long-term follow up (OR 0.24, 95% CI 0.17 to 0.34, 8 studies, n= 1719). Very few arterial complications, including haemorrhage, infection, cranial nerve palsies and pseudo-aneurysm formation were recorded with either patch or primary closure. No significant correlation was found between use of patch angioplasty and the risk of either perioperative (RR 0.62, 95% CI 0.18 to 2.09; 9 studies, n=1869) or long-term (RR 0.78, 95% CI 0.54 to 1.12; 7 studies, n=1332) all-cause death rates. There was a statistically non-significant decrease in any stroke or death during the perioperative period (OR 0.58, 95% CI 0.33 to 1.01; 8 studies, n= 1769), and a significant decrease during long-term follow-up (OR 0.59, 95% CI 0.42 to 0.84; 6 studies, n=1019).
Comment: The quality of evidence is downgraded by study quality (inadequate or unclear allocation concealment and blinding, and inadequate intention-to-treat adherence) and by imprecise results (few outcome events).