Fenestration Re-creation for Early Fontan Deterioration: Long-Term Hemodynamic and Clinical Outcomes.

Spontaneous closure of a Fontan fenestration may precipitate early hemodynamic deterioration in vulnerable patients. In such situations, fenestration re-creation may be considered as a rescue strategy when medical therapy is insufficient. However, the long-term hemodynamic consequences of this intervention remain poorly defined. We retrospectively reviewed 62 patients who underwent the Fontan procedure between January 2011 and December 2020 and subsequently experienced spontaneous fenestration closure. Patients were divided into two groups according to management strategy: those who underwent fenestration re-creation (Group 1, n = 19) and those managed without re-creation (Group 2, n = 43). Longitudinal hemodynamic data were analyzed using linear mixed models over a median follow-up of 10.2 years. Fenestration closed spontaneously at a median of 12 days (IQR 2.5-26.5) and initial re-creation was performed at the median of 42 days (IQR 11-213) postoperatively. Early and mide-term hemodynamic trends were broadly similar between groups, however, clear divergence emerged in the late follow-up. fenestration re-created patients demonstrated persistently higher central venous pressure and pulmonary vascular resistance, lower systemic vascular resistance, progressive increases in cardiac index, and declining oxygen saturation. Survival in this group remained above 80% during the mid-term follow-up but declined substantially in the late phase compared with patients without re-creation (52% vs. 85%, p = 0.043). This was accompanied by higher incidences of protein-losing enteropathy/plastic bronchitis, thromboembolism, and severe cyanosis. Fenestration re-creation may provide temporary hemodynamic stabilization in early Fontan deterioration; however, its benefits appear to diminish in the late phase. These findings highlight the need for hemodynamically tailored management strategies and alternative therapeutic options for patients with deteriorating Fontan circulation.