A 34-year-old woman with a history of primary amenorrhea and infertility presents to the emergency department with sudden-onset, severe chest pain that she describes as “sharp and tearing.” The pain radiates to her back. She is diaphoretic and anxious. Blood pressure is 182/96 mm Hg in the right arm and 146/88 mm Hg in the left arm. Pulse is 110/min. A new early diastolic murmur is heard at the left sternal border. Chest radiograph shows a widened mediastinum. CT angiography demonstrates a dissection flap involving the ascending aorta.

Which of the following is the most appropriate definitive management?