Image of the Week: Dyspnea and sharp abdominal pain radiating to the back

A 66-year-old man with a history of hypertension presents to the emergency department with dyspnea and sharp abdominal pain radiating to his back. On examination, his blood pressure is 180/120 mm Hg. A CT scan demonstrates the findings seen here, and laboratory testing indicates that his renal function is preserved. Which of the following is the most appropriate next step ...