Hybrid Palliation: Outcomes After the Comprehensive Stage 2 Procedure

Background: The comprehensive stage 2 procedure (CS2) follows initial hybrid stage 1 palliation for patients with single-ventricle physiology. The goal of this study was to describe CS2 outcomes and differences between survivors of CS2 (s-CS2) and nonsurvivors (nons-CS2). Method: All patients in The Society of Thoracic Surgeons Congenital Heart Surgery Database who underwent CS2 as index operation from 2010 to 2016 were included. Preoperative, operative, and postoperative data were analyzed, stratified by operative mortality (in-hospital or within 30 days of the operation), with univariate comparisons using χ², Fisher exact, or Wilcoxon rank sum tests. Results: Of 209 patients (49 centers) who met inclusion criteria, 141 patients had the diagnosis of hypoplastic left heart syndrome. Overall operative mortality was 12.4% (26 of 209). s-CS2 had a lower prevalence of preoperative extracorporeal membrane oxygenation use (0.0% vs 7.7%, p = 0.02) and less frequently underwent concomitant tricuspid valve procedures at the time of the operation (1.1% vs 11.5%, p = 0.01) than nons-CS2. Postoperatively, the prevalence of any of six The Society of Thoracic Surgeons Congenital Heart Surgery Database major complications was higher in nons-CS2 than in s-CS2 (53.9% vs 23.0%, p < 0.01), including a higher prevalence of renal failure (7.7% vs 0.6%, p = 0.04) and postoperative extracorporeal membrane oxygenation use (46.2% vs 2.7%, p < 0.01). There were no other preoperative, operative, or postoperative differences between the two groups. Conclusions: Operative mortality associated with the CS2 procedure is substantial, especially for patients receiving extracorporeal membrane oxygenation support after CS2. No obvious modifiable variables were noted between patients who died and those who survived.