Review of Management of the Borderline Left Ventricle: A Focus on Current Transcatheter and Hybrid Approaches

A borderline small left ventricle (LV), in which the LV is underdeveloped but not diminutive, represents an ongoing area of research and a challenge in clinical management. In this paper, the authors aimed to review the definition of borderline LV and recruitment strategies with a focus on hybrid, and wholly transcatheter approaches, to achieve the goal of two ventricle circulation.

Hampered by a lack of consensus definition; historically, patients with borderline LV were managed with single-ventricle palliation. However, due to the suboptimal long-term outcomes with single-ventricle palliation, many programs have adopted strategies to promote LV growth with the goal of achieving two-ventricle circulation with different outcomes. Initially dominated by surgical staging, there is growing evidence to support the use of hybrid or entirely transcatheter techniques to achieve first stage palliation in patients with borderline LV.

Regardless of technique used (surgical and/or transcatheter), recruiting the LV into a successful biventricular circulation typically requires multiple interventions aimed at improving blood flow through the left heart structures and increasing LV volume loading in an effort to promote LV remodeling. Scoring systems can be helpful tools in determining the candidacy for LV recruitment strategy; however, the optimal scoring system has yet to be established.