biostudies-literatureUnknown33(2)Ono M<h4>Objectives</h4>With improvements in early survival after the stage I palliation (S1P) Norwood procedure for hypoplastic left heart syndrome (HLHS) and its variants, inter-stage death accounts for an increasing proportion of mortality. Our aim was to identify the risk factors for inter-stage mortality.<h4>Methods</h4>The records of 322 neonates with HLHS or a variant who underwent the Norwood procedure at our centre between 2001 and 2019 were retrospectively analysed.<h4>Results</h4>The diagnoses included 271 neonates with HLHS (84%) and 51 with variants (16%). Aortic atresia was observed in 138 (43%) patients, mitral atresia in 91 (28%), extracardiac anomalies in 42 (13%) and genetic disorder in 14 (4%). The median age and weight of the patients at the S1P Norwood procedure were 9 (intInteractive cardiovascular and thoracic surgery218-226https://www.ebi.ac.uk/biostudies/studies/S-EPMC8691571biostudies-literaturePreoperative risk factors influencing inter-stage mortality after the Norwood procedure.PMC8691571Ono MHorer JWallner MEwert PCleuziou JBurri MHager ALemmer JStrbad MKido TfalsePreoperative risk factors influencing inter-stage mortality after the Norwood procedure.<h4>Objectives</h4>With improvements in early survival after the stage I palliation (S1P) Norwood procedure for hypoplastic left heart syndrome (HLHS) and its variants, inter-stage death accounts for an increasing proportion of mortality. Our aim was to identify the risk factors for inter-stage mortality.<h4>Methods</h4>The records of 322 neonates with HLHS or a variant who underwent the Norwood procedure at our centre between 2001 and 2019 were retrospectively analysed.<h4>Results</h4>The diagnoses included 271 neonates with HLHS (84%) and 51 with variants (16%). Aortic atresia was observed in 138 (43%) patients, mitral atresia in 91 (28%), extracardiac anomalies in 42 (13%) and genetic disorder in 14 (4%). The median age and weight of the patients at the S1P Norwood procedure were 9 (int2021-01-01T00:00:00Z2021 Jul2026-07-09T12:06:07.886Z2025-04-05T14:43:19.781ZS-EPMC86915713394864710.1093/icvts/ivab073