Synthetic versus biological patches for carotid endarterectomy

Extracranial carotid artery stenosis is a major cause of stroke. Carotid endarterectomy with patch angioplasty is a widely used surgical technique to reduce the risk of stroke in people with carotid stenosis. Patch materials include biological materials, like autologous vein or bovine pericardium, and synthetic materials, such as polytetrafluoroethylene (PTFE), Dacron, polyurethane, and polyester. This review is an update of one first published 30 years ago and last updated in 2021, and it has been conducted in line with current Cochrane guidance. In this update, we incorporated an expanded search strategy using additional databases and restructured our analytical framework to group patch materials into biological and synthetic categories. We also reassessed our level of certainty about the evidence.

To assess the benefits and harms of synthetic patch materials and biological patch materials (autologous vein and bovine pericardium) used in carotid endarterectomy, particularly for pseudoaneurysm outcomes, stroke, and death.

To identify studies for inclusion in this updated Cochrane review, we searched Embase Ovid, CINAHL (EBSCO), PubMed, Scopus, the Cochrane Library, ClinicalTrials.gov, and the WHO International Clinical Trials Registry Platform (ICTRP) to 30 April 2025. We also searched reference lists of relevant articles and conference proceedings.

We included randomised controlled trials (RCTs) that compared one type of carotid patch with another for carotid endarterectomy.

We prespecified seven main outcomes: perioperative ipsilateral stroke, perioperative arterial rupture, long-term ipsilateral stroke, long-term stroke (any type), long-term stroke or death, long-term arterial occlusion/re-stenosis greater than 50%, and long-term pseudoaneurysm formation. We defined perioperative outcomes as those measured up to 30 days after surgery and long-term outcomes as those measured up to at least one year after the operation (including events in the first 30 days). We considered other complications as secondary outcomes, but we did not prioritise these for presentation in our summary of findings table.

Two review authors independently assessed the risk of bias in the studies using the original Cochrane risk of bias tool RoB 1. We judged each domain as having low, high, or unclear risk of bias, and we resolved any disagreements about these judgements by discussion.

We used random-effects meta-analysis for primary analyses, with the restricted maximum likelihood (REML) method to estimate between-study variance. For meta-analyses including three or more studies and with heterogeneity greater than zero, we used the Hartung-Knapp-Sidik-Jonkman method to calculate confidence intervals; otherwise, we used Wald-type confidence intervals. Where only one study contributed data for an outcome, or event counts were too sparse for pooling, we reported study-level estimates narratively. We used GRADE to assess the certainty of the evidence for the main outcomes.

We identified one new study for inclusion from our updated searches, as well as several reports of extended follow-up data from previously included studies. Therefore, we included 15 RCTs involving 4971 participants in this review update. These studies contributed data on 2473 relevant carotid endarterectomy procedures. Twelve of the studies had long-term follow-up (mean follow-up ranged from 6 to 80 months).

Twelve of the included studies (with 2021 carotid endarterectomy procedures) contributed data to our main comparison of synthetic and biological patches. The evidence is very uncertain about the effect of synthetic patches compared with biological patches on perioperative ipsilateral stroke (OR 2.12, 95% CI 0.77 to 5.88; 5 studies, 797 participants), perioperative arterial rupture (OR 0.67, 95% CI 0.10 to 4.28; 6 studies, 1068 participants), and long-term pseudoaneurysm formation (OR 0.11, 95% CI 0.00 to 10.02; 5 studies, 980 participants) (all very low certainty evidence). Synthetic patches may result in little or no difference in long-term ipsilateral stroke (OR 1.60, 95% CI 0.79 to 3.26; 5 studies, 971 participants), long-term stroke (any type) (OR 1.21, 95% CI 0.67 to 2.18; 7 studies, 1167 participants), and long-term arterial occlusion or re-stenosis greater than 50% (OR 0.78, 95% CI 0.40 to 1.50; 9 studies, 1431 participants) compared to biological patches (all low-certainty evidence). Synthetic patches probably result in little or no difference in long-term stroke or death compared with biological patches (OR 1.01, 95% CI 0.91 to 1.12; 6 studies, 1115 participants) (moderate-certainty evidence). For most outcomes, we judged the certainty of the evidence as low or very low because studies were small, events were few, and confidence intervals were wide. Our concerns about study limitations also reduced our certainty about some outcomes.

This 2026 updated review incorporates an expanded search strategy and a restructured analytical framework that groups patch materials into biological and synthetic categories. It also includes data from one newly identified trial (195 participants), together with extended follow-up data for some previously included trials. We believe that these changes have improved the completeness and methodological quality of our evidence synthesis. The available evidence suggests that the use of synthetic patches after carotid endarterectomy may result in little or no difference in long-term ipsilateral stroke and stroke of any type compared to the use of biological patches. Synthetic patches may result in little or no difference in long-term arterial occlusion or re-stenosis greater than 50% compared to biological patches, and probably result in little or no difference in long-term stroke or death. The evidence is very uncertain about the effect of synthetic compared with biological patches on perioperative ipsilateral stroke, perioperative arterial rupture, and long-term pseudoaneurysm formation. Most findings were affected by study design limitations and imprecision. Large, high-quality trials are needed to confirm or clarify these findings.

None REGISTRATION: DOIs of previous review versions: https://doi.org/10.1002/14651858.CD000071; https://doi.org/10.1002/14651858.CD000071.pub2; https://doi.org/10.1002/14651858.CD000071.pub3; https://doi.org/10.1002/14651858.CD000071.pub4.