BackgroundThis meta-analysis aimed to consolidate existing data from randomised controlled trials on hypoplastic left heart syndrome.MethodsHypoplastic left heart syndrome specific randomised controlled trials published between January 2005 and September 2021 in MEDLINE, EMBASE, and Cochrane databases were included. Regardless of clinical outcomes, we included all randomised controlled trials about hypoplastic left heart syndrome and categorised them according to their results. Two reviewers independently assessed for eligibility, relevance, and data extraction. The primary outcome was mortality after Norwood surgery. Study quality and heterogeneity were assessed. A random-effects model was used for analysis.ResultsOf the 33 included randomised controlled trials, 21 compared right ventricle-to-pulmonary artery shunt and modified Blalock–Taussig-Thomas shunt during the Norwood …