A 62-year-old man with long-standing hypertension presents to the emergency department with sudden-onset, severe "tearing" pain that began in the anterior chest and radiates to the back. He is diaphoretic and anxious. Vital signs: T 37.0°C (98.6°F), BP 196/108 mm Hg, HR 118/min, RR 22/min, SpO2 95% on room air. Exam shows diminished breath sounds at the left lung base. Chest radiograph demonstrates a new left-sided pleural effusion compared with a film from 6 months ago. ECG shows sinus tachycardia without ischemic changes. Which of the following best explains the mechanism of this pleural finding in this patient?

(Assume no recent trauma or anticoagulant use.)