One and One-Half Ventricle Repair: Results and Concerns

Right ventricular stiffness constant as a predictor of postoperative hemodynamics in patients with hypoplastic right ventricle: a theoretical analysis

“…Recently, 1.5VR has been proposed to reduce the surgical risk of 2VR. The use of 1.5VR has lowered the early or midterm mortality, and adequate growth of RV and the tricuspid valve has been documented in some patients [2]. However, the postoperative RV dysfunction or arrhythmic event has also been reported, in particular, when the patients are on the borderline of criteria between 1.5VR and Fontan operation [4,5].…”

“…This indicates that RVEDV might be independent of the venous return to RA. Since RAP becomes higher than the atrial pressure of TCPC even in 1.5VR, supraventricular arrhythmias caused by high RAP are liable to occur [2,5]. In this condition, 1.5VR is considered to have hemodynamics equivalent to APC and needs larger stressed blood volume than does TCPC to maintain systemic arterial pressure (Fig.…”

“…Although systemic cardiac output in 1.5VR is also greater than that in Fontan operation, SVC pressure (which is equal to PAP) is higher than that of APC. Accordingly, the upper part of the body is exposed to higher SVC pressure in 1.5VR, which may cause postoperative pleural effusion [2]. A large pressure gradient between SVC and IVC also results in abnormal venous collaterals from SVC to IVC [17][18][19][20], and they could effectively increase the venous return to RA in 1.5VR.…”

“…Therefore, the blood from SVC directly enters PA, whereas the blood from the inferior vena cava (IVC) is pumped by RV to PA. This procedure is clinically acceptable because of its low surgical risk [1,2]. However, the benefits of this procedure on postoperative hemodynamics in patients with a wide spectrum of RV hypoplasia compared to other procedures such as biventricular repair (2VR) and Fontan operation remain unsettled [3].…”

“…Although various authors reported an arbitrary selection scheme for the procedures based on RV morphology such as RV end-diastolic volume (RVEDV) [1,2,5], the longterm outcomes of 1.5VR have remained insufficiently known [5]. The previous criteria do not likely predict postoperative hemodynamics of these complex circulations accurately because morphological values measured preoperatively largely depend on the RV preload and afterload conditions, which change remarkably between subjects and between before and after the operation.…”