Long-term therapeutic effect of Fontan conversion with an extracardiac conduit

Abstract

OBJECTIVES The aim of this study was to identify the long-term therapeutic effect of total cavopulmonary connection (TCPC) conversion with an extracardiac conduit. METHODS Between 1991 and 2014, 36 patients underwent TCPC conversion with an extracardiac conduit. Half of these patients were diagnosed with tricuspid atresia or its variant. The left ventricle was dominant in 26 patients (72.2%). Median age at conversion and interval from initial Fontan operation to conversion were 24.1 years (interquartile range 18.9–29.2) and 17.8 years (15.4–20.9), respectively. Surgical cryoablation was concomitantly performed in 32 patients (88.9%). Cardiac catheter examination was performed preoperatively (36 patients, 100%) and at 1 year (31 patients, 86%), 5 years (25 patients, 69%) and 10 years (13 patients, 36%) after TCPC conversion. Symptom-limited treadmill exercise with expired gas analysis was performed preoperatively (32 patients, 88.9%) and at 1 year (27 patients, 75.0%), 5 years (20 patients, 55.6%) and 10 years (12 patients, 33.3%) after conversion. RESULTS All patients received follow-up; the mean follow-up period was 8.2 ± 4.8 years. Actuarial survival rate, protein-losing enteropathy-free survival rate and rate of survival with sinus rhythm maintenance at 10 years were 79.2%, 67.8% and 48.5%, respectively. The survival curve declined steeply when the duration of Fontan circulation exceeded 25 years. New cases of protein-losing enteropathy developed postoperatively in 2 patients. Permanent pacemakers were implanted in 12 patients (33%), but atrial tachyarrhythmia was not sustained in any of the remaining patients. Pulmonary arterial pressure (11.0 ± 3.1 to 9.5 ± 3.6 mmHg, P = 0.003), pulmonary vascular resistance (2.1 ± 0.7 to 1.3 ± 0.5 WU/m2, P < 0.0001) and cardiac index (2.0 ± 0.3 to 2.9 ± 0.6 l/min/m2, P < 0.0001) significantly improved from preoperative evaluation to 1 year after the conversion, and these improvements were maintained during the entire follow-up period. Peak oxygen uptake remained unchanged from the preoperative evaluation (49.7 ± 11.5% predicted) to 1 year (52.5 ± 12.0%), 5 years (56.2 ± 9.6%) and 10 years (51.2 ± 9.4%) after conversion (P = 0.19). CONCLUSIONS Owing to its anti-arrhythmic effect and Fontan pathway recruitment effect, TCPC conversion with an extracardiac conduit prevented the natural decline of exercise tolerance that is seen in classic Fontan patients.

Narrative review of single ventricle: where are we after 40 years?

“…The atrio-pulmonary connection for Fontan completion has been complicated by failures caused by its nonergonomic hemodynamics, elevated rates of energy loss rate and elevated kinetic energy maximum value, as demonstrated in computational simulations (146,213,214). In these instances of failure, the original atrio-pulmonary connection has been converted either to a lateral tunnel (215,216) or to an extracardiac conduit (217)(218)(219), with better outcomes. The most frequent reason for Fontan failure is the occurrence and recurrence of supraventricular or ventricular arrhythmias (220)(221)(222)(223)(224).…”

Recent advances in biological pumps as a building block for bioartificial hearts

“…The Fontan circulation is particularly relevant during the surgical management of congenital patients with hypoplastic left heart syndrome (HLHS) (Hoashi et al, 2020;Chowdhury et al, 2022). HLHS is a condition in which neonates are born with a missing or underdeveloped left ventricle (Roeleveld et al, 2018;Bejjani et al, 2021;Birla et al, 2022;Jacobs, 2022).…”

“…During the Fontan operation, the inferior vena cava is separate from the heart and connected to the pulmonary artery using an inert Gore-Tex conduit (Roeleveld et al, 2018;Arunamata et al, 2020;Danton, 2021;King et al, 2022). This conduit only serves to provide a length of inert tubing to support blood flow and does not have a contractile function (Hoashi et al, 2020;Daley and d'Udekem, 2021;Lee et al, 2007;Ochiai et al, 2009;Perez-Caballero et al, 2022). However, replacing this inert conduct with a pulsatile biological pump will add additional functionality; the pulsatile activity of the pump can be used to support the flow of blood through the interior vena cava to the pulmonary artery.…”

Computed Tomography in the Evaluation of Fontan Circulation

“…The pacemaker is a crucial factor in imaging Fontan circuit. A study by Hoashi et al 13) showed that approximately 33% of patients with Fontan procedure required pacemaker implantation later in the life. Recent guidelines recommend that MRI can be performed in patients with implanted devices (MRI conditional or not) as long as safety conditions are met, but the significant artifacts generated due to the device, mainly from the packing box implanted in the chest wall, make the study non-diagnostic.…”