Interventions for Fontan Pathway Obstruction in Patients Following Total Cavopulmonary Connection

<b>Background/Objectives</b>: Obstruction of the Fontan pathway is a severe morbidity after total cavopulmonary connection (TCPC). This study aimed to evaluate the incidence and location of TCPC pathway obstruction and corresponding interventions. <b>Methods</b>: In all patients undergoing TCPC between 1994 and 2023, postoperative interventions for TCPC pathway obstruction were evaluated. Risk factors for TCPC pathway interventions were identified, and the impact of TCPC pathway interventions on late outcomes was analyzed. <b>Results</b>: Among 650 patients, 136 (21%) needed catheter/surgical interventions for TCPC pathway obstructions during the median duration of 0.2 (0.03-6.1) years postoperatively. Interventions comprised 128 catheters and 10 surgeries. Catheter intervention included 107 left pulmonary arteries (PA), 8 right PAs, and 27 extracardiac conduits. Surgery included eight conduit revisions, four PA enlargements, and two SVC enlargements. Freedom from interventions at 1, 3, 5, and 10 years was 87.7, 85.3, 83.6, and 78.5%, respectively. Previous Norwood procedure (HR: 2.228, <i>p</i> = 0.003), previous ductal stent (HR: 2.574, <i>p</i> < 0.001), previous PA interventions (HR: 2.514, <i>p</i> < 0.001), and high PA pressure before TCPC (HR: 1.161, <i>p</i> = 0.004) were risk factors. Patients requiring interventions had a higher incidence of protein-losing enteropathy (16.0 vs. 2.0%, <i>p</i> < 0.001), plastic bronchitis (8.3 vs. 0.8%, <i>p</i> < 0.001), and failing Fontan (28.6 vs. 7.6%, <i>p</i> < 0.001), compared to those who did not. <b>Conclusions</b>: Interventions for Fontan pathway obstruction were needed in 21% of patients. The left-PA stenosis was the main lesion, most cases of which were treated by stent implantation. Norwood procedure, ductal stent, pre-TCPC PA intervention, and high pre-TCPC PA pressure were identified as risks factors.