3 - Comparison of Surgical Options for Patients with Apicocaval Juxtaposition

Friday, February 8

1:45 PM - 2:00 PM

Location: Auditorium

Presenter(s)

ZW

Zhenglun (Alan) Wei, PhD

Research Engineer
Georgia Insitute of Technology

Author Only(s)

AY

Ajit Yoganathan, PhD

Professor
Georgia Institute of Technology
PT

Phillip Trusty, MSc

Graduate Research Assistant
Georgia Institute of Technology
MS

Morgan Stephens, BSc

Undergraduate Research Assistant
Georgia Institute of Technology
RS

Ritchie Solomon, MD

Professor
Amrita Institute of Medical Sciences and Research Centre
MK

Mahesh Kappanayil, MD

PROFESSOR
AMRITA INSTITUTE OF MEDICAL SCIENCES AND RESEARCH CENTER

Background:

Apicocaval juxtaposition (ACJ) is a rare form of single ventricle congenital heart defects, where the cardiac apex points towards the same side as the inferior vena cava (IVC). The Fontan procedure is a common operation for ACJ patients, and possible surgical options include ipsilateral, contralateral, and lateral-tunnel conduits. Concerns about these surgical options include inferior hemodynamic performance or risks of compression by the cardiac mass. Unfortunately, little information is available in the previous literature. This study conducted a computational analysis on nine ACJ patients to assess fluid mechanics and explore possible surgical improvements.

Methods:

Nine consecutive ACJ patients are included. An additional nine patients without ACJ were included as a reference cohort. Cardiac magnetic resonance (CMR) and phase-contrast CMR data were obtained for all patients, and computational simulations were performed to assess clinically important hemodynamic metrics including indexed power loss (iPL) and hepatic flow distribution deviation from 50% (HFD_off). The deformation index (DI) of the conduits were obtained to assess the risks of compression by cardiac mass. Additionally, a “virtual” surgery was performed in SURGEM III by implanting a straight lateral-tunnel conduit. This procedure was performed for three ipsilateral patients and three contralateral patients. Hemodynamic differences were investigated between original and straightened conduits.

Results:

The DI for ACJ is 19.3%±3.6%, which is in the DI range of non-ACJ patients (16% to 28%). The iPL for contralateral conduits (0.070±0.058) is higher than that for ipsilateral conduits (0.04±0.033) and non-ACJ conduits (0.034±0.015), but was not statistically significant. The HFD_off show no significant difference between ipsilateral, contralateral, and non-ACJ Fontan conduits (21±8%, 26±85, and 18±15%, respectively). Moreover, in the “virtual” surgery, the straight conduit reduced HFD_off (3±1%) and iPL (3±2%) from the ipsilateral conduits. The straight conduit also reduced HFD_off (5±1%) and iPL (21±14%) when compared to the contralateral conduits.

Conclusion:

These findings indicate that the current three surgical options for ACJ patients are equivalent in terms of iPL and HFD_off. However, the contralateral conduits are prone to worse energy efficiency, although it is not statistically significant. Moreover, this study shows that the ipsilateral conduits are not at risk of compression by the cardiac mass, which is a previous concern regarding this type of conduit. Therefore, it is suggested that the ipsilateral lateral-tunnel conduits are preferable for future ACJ patients in terms of hemodynamic performance. Nevertheless, superiority of a conduit should not only consider the hemodynamic performance of the conduit but also feasibility of surgical implementations and associated complications.