BACKGROUND: Since Fontan revision has been demonstrated to provide hemodynamic and symptomatic improvement in select patients with failing Fontan circulations, we now believe it is important to determine if one type of revision (lateral tunnel [LT] or extracardiac conduit [ECC]) provides superior outcomes. METHODS: Thirty-five Fontan revisions were performed (Jun 1997 to Dec 2004): 19 ECC (54%) and 16 LT. Preoperative variables were similar: New York Heart Association (NYHA) IV (LT = 4 vs ECC = 2, p = not significant [NS]), preoperative arrhythmias (LT = 13 vs ECC = 16, p = NS) and systemic right ventricle (LT = 4 vs ECC = 2, p = NS). Twenty-eight patients (80%) underwent a modified maze procedure (LT = 12 vs ECC = 16, p = NS) and 29 (83%) had pacemaker placement (LT = 11 vs ECC = 18, p < 0.05). RESULTS: There were no hospital deaths and no arrhythmias at hospital discharge. There were no differences in mean duration of intubation (LT 0.6 vs ECC 0.9 days, p = NS), inotropic support (LT 1.5 vs ECC 2.1 days, p = NS), intensive care unit stay (LT 2.6 vs ECC 3.5 days, p = NS), hospital stay (LT 8.8 vs ECC 9.7 days, p = NS), or episodes of acute postoperative arrhythmias (LT = 2 vs ECC = 4, p = NS). On intermediate follow-up (29 +/- 22 months), the overall cohort had 94% survival, 97% of survivors in NYHA class I/II, 91% freedom from late arrhythmias requiring medication, and no patient required cardiac transplantation. Follow-up revealed no differences in NYHA I/II (LT = 14 vs ECC = 18, p = NS), mortality (LT = 2 vs ECC = 0, p = NS), or late arrhythmia (LT = 4 vs ECC = 4, p = NS). CONCLUSIONS: Both the LT and ECC revisions provide symptomatic benefit for a failing Fontan connection and have equivalent early and intermediate results including arrhythmia recurrence.