Ranaboldo 1993.
| Study characteristics | ||
| Methods | Allocation concealment: opaque, sequentially numbered, sealed envelopes (arteries randomised) Blinding of outcome assessment: duplex and clinical FU blind Cross‐overs: 4 primary closure to patch (all analysed in original group) Exclusions during trial: none Participants lost to FU: 5 patch, 12 no patch (7.9%) | |
| Participants | Country: UK Number of participants: 199 Number of operations: 213 Sex: 69% male Mean age: 66 years % asymptomatic carotid disease: 8% % stenosis: > 75% stenosis in 60% of arteries Comparability: age, sex and vascular risk factors not reported by treatment group | |
| Interventions | Treatment: autologous vein patches (53 arteries) or Dacron patches (56 arteries); non‐random allocation Control: primary closure % shunted: shunt 'when technically possible' Medication: aspirin before surgery, unknown after surgery | |
| Outcomes | Death within 30 days and during FU; stroke within 30 days and during FU; perioperative occlusion (duplex); wound haemorrhage or infection; restenosis > 50% or occlusion at end of FU (duplex) | |
| Notes | Exclusion criteria: unknown FU: 12 months Funding sources for the study: none reported | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Sequentially numbered (artery randomised). |
| Allocation concealment (selection bias) | Low risk | Opaque sealed envelopes. |
| Blinding of participants and personnel (performance bias) All outcomes | High risk | Blinding of study participants not reported. Because of the nature of the intervention (patch or primary closure), the surgeon could not be blinded. |
| Blinding of outcome assessment (detection bias) All outcomes | Unclear risk | Blinding of outcome assessment not reported. |
| Incomplete outcome data (attrition bias) All outcomes | High risk | 7.9% of participants lost to follow‐up. |
| Selective reporting (reporting bias) | Unclear risk | Unclear whether study authors reported the results of all prestated outcomes. |
| Other bias | Low risk | None suspected. |
CABG: coronary artery bypass graft; CEA: carotid endarterectomy; DSA: digital subtraction angiography; FU: follow‐up; ICA: internal carotid artery; NIRS: near infrared spectroscopy; PTFE: polytetrafluoroethylene; RIND: reversible ischaemic neurological deficit; TIA: transient ischaemic attack.