Impact of RIVP on GI Function in Patients Undergoing Surgical Repair for ATAAD

Retrograde inferior vena cava (RIVP) involves perfusing oxygenated blood into the inferior vena cava, which then flows towards the viscera, abdominal organs and lower extremities. By maintaining perfusion to these regions during cardiopulmonary bypass (CPB) and induced hypothermia, Retrograde inferior vena cava (RIVP) helps mitigate the risk of ischemic injury to the abdominal organs. Following the initiation of total cardiopulmonary bypass, the body temperature will be gradually lowered to achieve deep-moderate hypothermia ( 24-38°C). This procedure will involve the combination of selective antegrade cerebral perfusion and retrograde inferior vena cava perfusion. Antegrade perfusion will be maintained at a flow rate of 5-7mL/min/kg, while retrograde perfusion will be regulated to sustain the required pumm pressure and blood flow.

After mild to moderate hypothermia is achieved, a cannula will be inserted into the right axillary artery, brachiocephalic or innominate artery to provide continuous flow to the brain. A flow rate of 5-7mL/min/kg will be maintained.