Hybrid Procedures in the Management of Hypoplastic Left Heart Syndrome: A Systematic Review

Abstract Background/Objectives: HLHS is considered one of the most severe congenital heart defects and occurs in approximately 2-3% of all CHD cases. Hybrid procedures have been introduced as an alternative to traditional surgical techniques, such as the Norwood procedure, particularly for neonates at high risk. Although the hybrid approaches claim to reduce surgical risks and improve recovery, little is known regarding their comparative effectiveness and safety. This review aims to describe the contribution of hybrid procedures in HLHS management regarding survival rates, postoperative complications, and quality of life through recovery outcomes and long-term results in light of conventional surgical techniques. Methods: A systematic review was carried out following the PRISMA guidelines. Data will be retrieved from PubMed, Cochrane Library, Scopus, and ClinicalTrials.gov. The search will include articles published from January 2014 to November 2024. Inclusion will be focused on pediatric patients diagnosed with HLHS and studies comparing hybrid procedures versus traditional surgical methods. All screening, data extraction, and quality assessment will be done by two independent reviewers. Results: This review analyzed data from 11 studies comprising 934 neonates with Hypoplastic Left Heart Syndrome (HLHS), with 371 undergoing hybrid procedures and 563 receiving the Norwood procedure. The findings demonstrate that both approaches achieved comparable survival rates at 1, 3, and 5 years. Hybrid procedures were linked to slightly earlier interventions (SMD = -0.10, 95% CI: -0.61 to 0.41, p = 0.77) and were favored for high-risk neonates due to reduced invasiveness. However, hybrid procedures exhibited a higher rate of interstage mortality (SMD = 0.81, 95% CI: -0.62 to 2.25, p = 0.09) and pulmonary artery stenosis requiring reinterventions (30% vs. 18% for Norwood). Norwood procedures were associated with fewer reinterventions and lower interstage mortality, highlighting their effectiveness for stable patients. Conclusions: Hybrid procedures offer a practical alternative to the Norwood procedure, especially for high-risk neonates. Although both approaches show similar long-term survival rates, hybrid procedures are associated with a higher risk of complications, including increased interstage mortality. These challenges highlight the need for continued advancements to refine hybrid techniques and improve long-term outcomes. This review emphasizes the critical role of tailored patient selection and calls for further research to enhance hybrid procedure protocols and optimize their effectiveness for specific patient populations.