The long-term outcome of extra cardiac lateral tunnel total cavopulmonary connection
Authors: Nishiori H N , Aoki M A , Hagino I H , Koshiyama H K , Ito T I , Kumae M K 
Published: October 2022

Abstract

Background
Although early results of total cavopulmonary connection (TCPC) using an extracardiac conduit are favorable, the patients' growth leads to linearization of the Fontan route causing energy loss by collision of blood flow from the SVC and the IVC, and PV compression. Use of oversized conduit in young children also causes energy loss due to caliber change, and a risk of thrombosis by flow stagnation. We have performed TCPC with the Extra Cardiac Lateral Tunnel (ECLT) technique using e-PTFE patch to make an angled route design for laminar IVC and SVC blood flow confluence, and to avoid caliber change of the IVC-Fontan route.

Purpose
To clarify the long-term outcome of the Extra Cardiac Lateral Tunnel TCPC (ECLT-TCPC) using e-PTFE patch.

Methods
Medical records of the patients who underwent staged ECLT-TCPC from April 2003 to March 2020 were reviewed retrospectively. The surgical technique consists of creation of IVC and PA opening connected by atrial appendage and free wall as a floor and suturing a cut-open e-PTFE graft over the anterior external wall of the right atrium to make a Fontan route 14–16 mm in diameter entering the PA from the ventral aspect to merge the SVC flow with an angle. Sixty five patients were included in the study: 46 cases of functional single ventricle, 10 HLHS, 9 tricuspid atresia. Age at surgery were 33.0±22.2 month and the weight was 11.1±3.7 kg. Preoperative catheterization data were following; PA pressure: 10.3±4.0 mmHg, PVR: 1.9±0.65 woods.

Results
We had one in-hospital death (1.8%) and three long-term deaths (6.2%) during a follow-up period of 7.3±4.3 years. Long-term complications included 6 cases of arrhythmias requiring medical or surgical treatment. Other complication included 2 cases of thrombotic complications, and 1 case of hemorrhagic complication. Two patients underwent re-operation for TCPC: 1 cyanosis due to residual shunt and 1 cases for occlusion of the Fontan route. The anticoagulant therapy was usually terminated eight months after surgery. At the latest follow-up, 55 (84.6%) patients were anticoagulantion-free. At the one-year follow-up, the diameters of the Fontan route were 11.0±2.4mm at the PA anastomosis level, 10.8±2.5mm at the middle level, 10.0±2.5mm at the IVC anastomosis level. At the latest follow-up, the diameters of the Fontan route at the three levels were 14.9±3.4mm, 13.0±3.2mm, and 13.6±4.9mm, respectively. Using the normal IVC diameter as a reference, the Fontan route diameter at the three levels were 127±35%, 123±28%, and 143±44% of Normal, respectively, remaining above 100%Normal. The pressure gradient between IVC and PA was 1.5±1.0mmHg at the latest follow-up, and no significant changes in the route design were noted.

Conclusion
The long-term results of ECLT TCPC using e-PTFE patch seemed acceptable. This technique may provide advantages of a long-term maintenance of the Fontan route diameter and design, and an option of a long-term freedom form anticoagulation.

Funding Acknowledgement
Type of funding sources: None.