Development of a biventricular conversion program: A new paradigm

Abstract

Background Borderline small ventricular size or technical issues precluding the use of both ventricles may lead to single ventricle palliation. Fontan complications have led some centers to look for alternatives to the traditional pathway. The objective of this study is to evaluate the essential philosophy and outcomes of a new biventricular (BiV) conversion program. Methods The prospectively collected Children's Memorial Hermann Heart Institute Society of Thoracic Surgeon's Database was retrospectively reviewed between July 2017 and July 2020. Results Thirteen patients met inclusion criteria and underwent BiV conversion during that time. The most frequent diagnosis was malposed great arteries and a ventricular septal defect (VSD) in 4 (31%) patients. Seven (54%) patients were in the first interstage, and 1 (8%) patient had already undergone a Fontan operation before their BiV conversion operation. One or more risk factors for single ventricle palliation (genetic syndrome ≥ moderate atrioventricular valve regurgitation ≥ moderate ventricular dysfunction, presence of signs of Fontan failure) were present in 3 (23%) patients. The median left ventricular end diastolic pressure increased from 5.5 mmHg (4–10 mmHg) to 10 mmHg (6–20 mmHg) postoperatively (p < .05). The right ventricular pressure (RVP) was estimated as less than half systemic in all six patients who were able to be estimated. At a median follow‐up of 22.6 months (0.3–36.4 months), 12 (92%) patients are alive. Conclusions BiV conversion is feasible with reasonable short‐term clinical outcomes. Mortality risk is low, but as seen in other studies, the risk of reintervention is high.

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

“…In our experience, for all newborns with borderline left heart structures, the pathway towards a bi-ventricular circulation is considered, utilizing appropriate staging of surgical procedures (183,184). For other patients on a uni-ventricular pathway, either a Norwood, bidirectional Glenn, or Fontan completion, extensive imaging and functional investigations are performed before ruling out the possibility for a bi-ventricular conversion (183)(184)(185)(186)(187)(188)(189)(190)(191)(192)(193).…”

“…In our experience, for all newborns with borderline left heart structures, the pathway towards a bi-ventricular circulation is considered, utilizing appropriate staging of surgical procedures (183,184). For other patients on a uni-ventricular pathway, either a Norwood, bidirectional Glenn, or Fontan completion, extensive imaging and functional investigations are performed before ruling out the possibility for a bi-ventricular conversion (183)(184)(185)(186)(187)(188)(189)(190)(191)(192)(193). This decision-making process requires careful consideration of the size of inflow and outflow of the systemic ventricle, morphology and shunt direction through any interatrial and/or ventricular communication, right and left ventricular function and volumes, and morphology and flow of ascending aorta and aortic arch (183,184).…”

A Review of Biventricular Repair for the Congenital Cardiac Anesthesiologist

“…20 Although our program has undertaken an aggressive approach to EFE resection, we acknowledge that other institutions have chosen not to perform resection of EFE on the basis of concerns for persistent diastolic dysfunction despite adequate relief of EFE. 21 Additional Pulmonary Blood Flow ("Super Glenn")…”

Modern advances regarding interatrial communication in congenital heart defects

“…47 In recent years, various surgical approaches have been pursued to achieve a biventricular circulation. 43,[48][49][50][51][52] The presence of an interatrial communication in patients with borderline left heart structures has been utilized during the fetal life as factor to promote potential growth of the left heart structures. This strategy is based on observations of the correlation between the presence and flow direction through the patent foramen ovale, and the potential association with later biventricular repair.…”

“…With these observations in mind, the presence of an interatrial communication has been utilized, by some colleagues, during the process of left ventricular recruitment. [55][56][57][58][59] In our clinical practice, 51 complete patch closure of the interatrial septum (Figure 5) has been used to promote increased blood flow through the left heart, to favor the growth of the left heart structures, to make them capable of delivering the required systemic cardiac output. Our approach has been recently confirmed by an extensive review of the Congenital Heart Surgeons Society, where in patients with atrio-ventricular septal defect an atrial communication at biventricular repair was associated with significantly reduced long-term survival, after adjusting for other known associated factors, including unbalance.…”