Mid and long-term evaluation of left modified blalock-taussig shunt after cavopulmonary shunts: A retrospective cohort study

. ABSTRACT Background: Congenital heart diseases are the most common type of congenital malformations. Some of them may pass unnoticeable in the first days or maybe years of life, but the others are pretty serious and life-threatening due to major malformations that lead to the mixing of oxygenated and deoxygenated blood. Most of these cases are not repairable and require separating the venous and arterial blood to help improve oxygen saturation (SpO 2 ). Aim: The study aims to evaluate the mid and long-term effects of left modified blalock-taussig (MBT) shunt after bidirectional cavopulmonary shunt. Patients and Methods: A retrospective cohort study was conducted on 20 patients who underwent MBTS after Bidirectional Glenn. We evaluated the mid and long-term effects of MBTS in those patients, especially SpO 2 and echocardiographic findings. The study considered the ethical principles of the Helsinki Declaration approval from the research ethics committee at our institution (MS 510/2023). Results: There was a significant increase in postoperative SpO 2 in comparison to preoperative SpO 2 ( P<0.001 ) with a mean difference of 20.95%. Conclusion: Congenital cyanotic heart disease represents a life-threatening condition where the main problem is desaturation due to the mixing of arterial and venous blood. Bidirectional Glenn is a step to separate the oxygenated and deoxygenated blood. But later on, SpO 2 continues to decline and further intervention is needed. In this study, we found that MBTS provides a postoperative significant increase in SpO 2 in a wide group of those patients even who are not candidates for other operations without significant complications.