A dramatic learning curve of extracardiac Fontan operation in the modern era.

Background: This study aimed to describe the learning curve of the extracardiac Fontan procedure in a single center and to analyze the changes in clinical applications and outcomes.

Methods: A retrospective chart review of all extracardiac Fontan patients in a single tertiary care center was undertaken. Patients with a diagnosis of hypoplastic left heart syndrome and those who had undergone a lateral tunnel modification, intra/extracardiac Fontan, Kawashima procedure, or inferior vena cava-to-azygous vein connection were excluded from the analysis.

Results: Between May 2004 and February 2018, data of 159 extracardiac Fontan patients were analyzed. The median age was 5.5 years (range 4.5-8.2 years). Based on a cumulative sum analysis, a hinge point was determined to divide the cohort into 2 phases. Phase 1 ( n = 70) represented the first learning phase and phase 2 ( n = 89) represented the later phase. Mortality decreased in phase 2 (2/89; 2%) compared to phase 1 (10/70; 14%; p = 0.004). Two (3%) patients had extracorporeal membrane oxygenation in phase 1, and 5 (6%) in phase 2 ( p = 0.47). More patients in phase 2 underwent a prior bidirectional Glenn procedure (83/89 vs. 57/70; p = 0.02), fenestration (80/89 vs. 9/70; p < 0.001), and pulmonary artery reconstruction (37/89 vs. 2/70; p < 001).

Conclusions: This study shows that increased use of extracorporeal membrane oxygenation, strict implementation of the three-stage management plan, routine fenestration, and a low threshold for pulmonary artery reconstruction may be associated with decreased mortality in the extracardiac Fontan procedure.