Reply: Additional “customized” aortopulmonary shunt may increase “vis a tergo” to rescue a failing bidirectional cavopulmonary shunt

Abstract

The authors reported no conflicts of interest.The Journal policy requires editors and reviewers to disclose conflicts of interest and to decline handling or reviewing manuscripts for which they may have a conflict of interest. The editors and reviewers of this article have no conflicts of interest. The authors reported no conflicts of interest. The Journal policy requires editors and reviewers to disclose conflicts of interest and to decline handling or reviewing manuscripts for which they may have a conflict of interest. The editors and reviewers of this article have no conflicts of interest. I discussed in my first Commentary that the necessity of an unrestricted passive systemic blood flow to the pulmonary artery is of paramount importance for the optimal function of a Fontan circulation.1Luo S. Haranal M. Deng M.X. Varenbut J. Runeckles K. Fan C.P.S. et al.Low preoperative superior vena cava blood flow predicts bidirectional cavopulmonary shunt failure.J Thorac Cardiovasc Surg. 2020; 160: 1529-1540Abstract Full Text Full Text PDF PubMed Scopus (8) Google Scholar,2Carrel T. “Vis a tergo”—“A push from behind” is of paramount importance for the optimal function of a bidirectional cavo-pulmonary shunt.J Thorac Cardiovasc Surg. 2020; 160: 1541-1542Abstract Full Text Full Text PDF Scopus (1) Google Scholar As additional information, Türköz and Dogan3Türköz R. Dogan A. Management for bidirectional cavopulmonary shunt failure: adding aortopulmonary shunt without takedown.J Thorac Cardiovasc Surg. 2021; 161: e321-e322Abstract Full Text Full Text PDF PubMed Scopus (3) Google Scholar report on 2 cases in which an additional aorto-to-left pulmonary artery shunt with a banding performed between the Glenn anastomosis and the shunt to pulmonary artery anastomosis helped to manage a situation of a failing bidirectional cavopulmonary shunt. This shunt, with a minimal pulsatility, helped to increase the “vis a tergo” (a power from behind) that I had postulated as important feature for the success of a Glenn shunt. In fact, the solution proposed by the colleagues from Turkey was successful and contributed most probably to reduce the perioperative risks that may have been associated with a take-down. Both patients survived, had an improved oxygen saturation, and central venous pressure decreased slightly within hours. I believe there are important aspects that may be discussed in relation to this additional report: the size of the shunt (3 instead of 4 mm?) and the optimal technique to regulate the flow (and therefore the pressure gradient) across the shunt. Another important point would be to discuss the optimal time point to disconnect the main pulmonary artery from the pulmonary bifurcation during the index procedure. One advantage of preserving the continuity would be that the shunt could be anastomosed to the main pulmonary trunk (perhaps easier in some instances because of the size) and the banding could be placed proximal to the bifurcation. This would eliminate the risk of additional intervention on the left pulmonary artery, even though this was successfully performed in the described case. This may appear to be in contradiction to what I wrote in my first Commentary, eg, that one of the most important strategies to increase superior vena cava blood flow is probably the elimination of antegrade pulmonary blood flow that competes with superior vena cava flow. With the interposition of a tight banding, this contradiction may become relative only. Management for bidirectional cavopulmonary shunt failure: Adding aortopulmonary shunt without takedownThe Journal of Thoracic and Cardiovascular SurgeryVol. 161Issue 4PreviewWe read with great interest the article entitled “Low Preoperative Superior Vena Cava Blood Flow Predicts Bidirectional Cavopulmonary Shunt Failure” by Luo and colleagues.1 The authors appreciably demonstrated that low preoperative superior vena cava blood flow was associated with low arterial saturation and poor clinical outcome following bidirectional cavopulmonary shunt (BCPS). We congratulate the authors for this inspiring study; however, we would like to add some comments on one aspect. In this study, the authors performed BCPS takedown on the patients who had BCPS failure. Full-Text PDF