A 72-year-old man with a history of hypertension and chronic kidney disease (eGFR 35 mL/min/1.73m²) presents with a 2-month history of rest pain in the left foot. Duplex ultrasonography reveals a 4.5 cm infrarenal abdominal aortic aneurysm (AAA) with no evidence of dissection. His left lower limb shows critical limb ischemia with an ankle-brachial index (ABI) of 0.4. Which of the following is the most appropriate next step in management?