Biventricular Repair Enabled by Favorable Anatomy in Heterotaxy Syndrome with Interrupted Inferior Vena Cava: An Abstract from Akron Children’s Hospital Resident and Fellow Academic Day

Heterotaxy syndrome occurs in three percent of congenital heart disease patients and often precludes biventricular repair1. Biventricular repair can avoid the long-term sequelae of SV physiology, but is challenging, especially with atrioventricular canal defects with systemic or pulmonary venous anomalies2. We present a successful biventricular repair in a patient with a balanced complete atrioventricular septal defect (CAVSD), interrupted inferior vena cava (IVC) with azygous continuation, and anomalous left-sided hepatic venous return to the left atrium and right-sided hepatic venous drainage to the right atrium. The patient was prenatally diagnosed with heterotaxia, left atrial isomerism, and CAVSD. Postnatal echocardiography demonstrated a balanced Rastelli A CAVSD with favorable common atrioventricular valve (CAVV) function. At 3 months, echocardiography suggested more complex anatomy, prompting a computed tomography angiography scan and a three-dimensional volume rendering technique (Figures 1 and 2). Left ventricular hypertrophy prompted cardiac catheterization, which demonstrated a balanced CAVSD with normal filling pressures (LVEDP 7- 8 mmHg, RVEDP 3-8 mmHg). Common atrioventricular valve (CAVV) function was preserved with mild regurgitation, and pulmonary over-circulation (Qp:Qs 2.8:1) with elevated pulmonary vascular resistance (PVR); given these findings, pulmonary artery (PA) banding was indicated to reduce pulmonary pressures and allow somatic growth prior to biventricular repair. CT imaging enabled a 3D model for biventricular planning. Main PA banding achieved a Qp:Qs of 0.7:1 and saturations of 85%. At 11 months, repeat catheterization demonstrated improved hemodynamics, and biventricular repair was undertaken with PA de-banding. The operation included septation of the CAVSD with two autologous pericardial patches, with intra-atrial baffling of the challenging anomalous left hepatic vein to the right atrium. Intraoperative transesophageal echocardiography showed no residual shunt, excellent atrioventricular valve function, and RVOT <10 mmHg. The postoperative course was notable only for a transient junctional rhythm. At 12 months, the patient was doing well, and follow-up echocardiography demonstrated normal left and right systolic ventricular function, unobstructed hepatic venous flow, and no significant supravalvular pulmonary stenosis. Biventricular repair in heterotaxy is exceedingly rare and presents a technical surgical challenge when complex intracardiac and hepatic venous anomalies coexist. To our knowledge, this report represents the first reported successful biventricular repair in left atrial isomerism with isolated left hepatic drainage to the left atrium3,4. This case underscores the importance of a staged surgical strategy. PA banding enabled physiologic optimization and growth, facilitating definitive repair under improved hemodynamic conditions. Equally critical was the use of multimodality imaging, including three-dimensional modeling to facilitate construction of the complex intracardiac baffle. This approach expands the boundaries of biventricular repair in heterotaxy and demonstrates a case where the Fontan physiology and its long-term sequelae could be avoided. This case represents a rare and previously undescribed biventricular repair in left atrial isomerism with isolated left hepatic venous drainage to the left atrium. It demonstrates that complex venous anatomy alone should not preclude septation when ventricular balance and atrioventricular valve competence are favorable.