ObjectiveTo evaluate the long-term effects of fenestration on patients at different risk levels, who performed external conduit total cavo-pulmonary connection operation.MethodsThis was a retrospective analysis which enrolled 383 patients undergoing external conduit total cavo-pulmonary connection in Fuwai Hospital from 2008 to 2015. Based on the preoperative data and whether fenestration in the operation, the whole cohorts were divided into four subgroups: a high risk group with fenestration(mean age: 10.53±7.06 years, 55 males), a high risk group with non-fenestration(mean age: 9.30±7.83 years, 43 males), a low risk group with fenestration(mean age: 8.91±7.13 years, 65 males) and a low risk group with non-fenestration(mean age: 8.23±5.34 years, 67 males). Then we collected and analyzed the perioperative data and long-term prognosis of this cohorts in different risk levels.ResultIn the high-risk group, the duration of chest drainage in fenestration group was significantly shorter than that of the non-fenestration group (12.39±12.03 d vs. 23.30±15.36 d, P=0.001). The incidence of delayed chest drainage in the fenestration group was lower than that in the non-fenestration group (25.0% vs. 47.1%, P=0.002). In addition, the length of hospital stay was shorter than that of the non-fenestration group (18.91±12.79 d vs. 29.68±37.77 d, P=0.004), with significant statistical difference. In the low risk group, there were 3 (2.7%) and 2 (1.6%) deaths at the follow-up in the non-fenestration and fenestration groups respectively (P=0.761). And 1 patient (1.3%), 1 patient (1.4%) died in the fenestration and non-fenestration group (P=0.593) in high risk group. However, there was no statistically significant difference among the fenestration and non-fenestration groups in terms of long-term intestinal protein loss syndrome and arrhythmia in different risk level groups.ConclusionFenestration can reduce the incidence of early complications and hospital stay, effectively, especially for the high-risk patient. Fenestration is recommended for high-risk patients with external conduit total cavo-pulmonary connection operation.