Discussion:
This case presents a number of challenges that we had to tackle, one of which was vaso-occlusive crisis during aortic root replacement which is considered one of the major surgeries. To overcome this, our surgical plan included:
Exchange transfusion, which can aid in two ways, one is by reducing HbS, and the other is by increasing the preoperative hematocrit level. Thus, facilitating a better oxygen delivery to the tissues. [2, 7] This measure was taken preoperatively and reduced the HbS to 73.5. Also, perioperative exchange transfusion was done to reduce the vaso-occlusive Crisis.
Mild hypothermia (> 32°C) is traditionally used for myocardial preservation by decreasing the metabolic rate and reducing the oxygen demand. However, hypothermia in patients with sickle cell anemia is still controversial with almost half of the published reports’ patients were maintained on normothermia during CPB, the rest underwent a mild hypothermia (> 32°C). [1]
ln our case, aiming at minimizing the risk of vaso-occlusive crisis, we performed a mild hypothermia of 34°C during the surgery, CPB flows were maintained at a minimum cardiac index of 2.4 L/min, venous saturation was kept >70%, and no acidosis occurred during the CPB period. There was no major vaso-occlusive crisis occurred throughout the surgery
Another challenge is mechanical vs biological valve. Even though mechanical valves are superior in durability, they are linked with an increased risk of thrombosis, hemolysis, sickle cell crisis, and lifelong anticoagulation use, which can predispose the patient to hemorrhagic complications. [5] [1] In our case, when measuring the risk and benefits of both types and due to his young age, we prioritized the use of a mechanical valve.