A 68-year-old man with a history of hypertension and smoking presents to the emergency department with sudden-onset severe back pain radiating to the left flank. He is diaphoretic and appears in distress. Blood pressure is 165/95 mmHg in the right arm and 140/85 mmHg in the left arm. Pulse is 110/min. On examination, a pulsatile abdominal mass is palpable. A stat CT angiography of the chest and abdomen with IV contrast shows a large infrarenal aortic aneurysm with active extravasation of contrast into the retroperitoneum. What is the most appropriate immediate management?