Role of flow preference in decision making regarding the use of Blalock-Taussig shunt

I read with great interest the work by Arnaz et al. (1) published in your journal. I noticed that the authors did not comment on the flow preference in their study. I suggest that flow preference is an important factor influencing the success of shunt surgery. Notably, Blalock–Taussig shunt (BTS) surgeries are challenging in new-borns because of unpredictable short- and long-term outcomes in each patient (2). Surgical planning and decision making for the location of the shunt, graft diameter, and type of shunt are crucial for the success of surgery. The primary goal of shunt surgery is often to increase pulmonary blood flow and/or to promote pulmonary artery growth. Pulmonary blood flow is an important factor for vessel growth, which has been demonstrated especially in patients with shunts (3). Therefore, I suggest that flow preference is an important factor for surgeons to plan the shunt location and type. Although not discussed in this manuscript, right modified BTS flow preference is consistently toward the right pulmonary artery regardless of pulmonary artery diameter or resistance and anastomosis angle