Emergency Aorto-Pulmonary Shunt Using <i>Two IV Cannulas Technique</i>: A Rapid Stabilization Technique for Cyanotic Spells in Tetralogy of Fallot Before Cardiopulmonary Bypass

Perioperative cyanotic spells in Tetralogy of Fallot (TOF) patients during the initiation of surgery can lead to profound desaturation & hemodynamic unstability. These spells are characterized by acute desaturation due to increased right-to-left shunting, often triggered by anesthesia induction, stress, or changes in vascular resistance. In severe cases, standard medical management—including fluid boluses, vasopressors, and beta-blockers—may fail, necessitating urgent intervention to restore pulmonary blood flow or put patient immediately on cardiopulmonary bypass (CPB). We encountered such a scenario in a 5-year-old child scheduled for total correction of TOF. Preoperative imaging had revealed good-sized branch pulmonary arteries but significant right ventricular outflow tract (RVOT) obstruction at valvular level. Two large major aortopulmonary collateral arteries (MAPCAs) had been coiled preoperatively. During anesthesia induction, the child developed a severe cyanotic spell perioperatively, with saturations progressively dropping below 20%. Despite aggressive conventional management, including oxygenation, deep sedation, and vasoactive support, the spell remained refractory, and the patient’s condition deteriorated rapidly. These measures failed to improve oxygenation, and decision was taken to immediately put patient on CPB.<i>Recognizing the urgency, we immediately performed an emergency sternotomy to put patient on CPB, but as setting up CPB would take several minutes, meanwhile we also tried to stabilise the child by rapidly restore pulmonary circulation with our innovative novel Two IV Cannula technique: inserting a 14F IV cannula into the ascending aorta and another 14F IV cannula into the distal pulmonary artery, then connecting them with a standard IV tubing connector. This setup created a temporary aorto-pulmonary shunt within few seconds, functionally resembling a Blalock-Taussig-Thomas (BTT) shunt, allowing blood to bypass the obstructed outflow tract and directly perfuse the pulmonary circulation. This simple yet life-saving maneuver resulted in an immediate and dramatic improvement in oxygenation/saturation within few seconds, providing crucial time for controlled CPB initiation. </i>Within seconds, the patient’s oxygen saturation improved dramatically from 20% to 70%, and hemodynamic stability was restored and allowing a controlled transition to CPB. This rapid stabilization technique using IV cannula in perioperative spelling child provided crucial time for CPB initiation under controlled conditions. The IV cannulas were then removed, and the total correction was successfully performed with a transannular patch. <i>This simple, easily replicable </i>& <i>innovative Two IV cannulas technique offers a life-saving bridge to CPB in cases of refractory cyanotic spells. It is easy to implement, requires minimal equipment, achieved in few seconds and can be performed by an assistant while the primary surgeon continues with CPB cannulation. This approach may be especially useful in resource-limited settings & serves as an effective interim measure to stabilize the patient until bypass is established.</i>