Thepurposeofguidelinesistopresentevidence-basedinstructiontocliniciansonhowbesttotreattheirpatients.Guidelinesshouldprovideuswithatemplateforpracticeandsummarizetheevidenceinsuchawayastoprotectboththepatientandtheclinician.TheNationalInstituteforHealthandCareExcellence(NICE)guidelinesonabdominalaorticaneurysm(AAA)repairfailedmiserablyinthisrespect.Theyprovidequestionsbutfewanswers.Thewriting