Aalders 1992.

Methods	Site: Femoral to AK popliteal Study design: Single‐centre RCT Method of randomisation: sealed envelopes Blinding: unblinded, intention to treat Exclusions post randomisation: none Losses to follow up: none
Participants	Country: Holland No. of participants: 85 patients(93 limbs; 46 PTFE, 47 HUV) Age: 64 yrs Sex: 67 male, 18 female DM 16, critical 17 Inclusion criteria: AK femoro‐popliteal graft for IC (or limb salvage if vein unavailable) Exclusion criteria: those with previous femoro‐popliteal graft
Interventions	6 mm PTFE versus 6 mm HUV
Outcomes	Primary patency, secondary patency, complications
Notes	All had post‐op anticoagulants
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Random permuted blocks"
Allocation concealment (selection bias)	Unclear risk	Not specifically stated. Probably not done
Blinding of participants and personnel (performance bias) All outcomes	High risk	Operative blinding impossible in this type of trial
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Outcome assessors and patients not obviously blinded
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Some patients lost to follow‐up early on, but clear life table data
Selective reporting (reporting bias)	Low risk	All stated outcomes reported
Other bias	Low risk	No other obvious bias