Treatment Strategy of Intramural Hematoma
Patients with uncomplicated IMHBs received medical therapy to control their pain (intravenous opiate analgesia), heart rate (less than 80 beats per minute), and blood pressure (systolic blood pressure between 100 and 120 mmHg) [1] . The acute phase was defined as the first fourteen days from the onset of IMHB, and the disease was considered stable after an uneventful fourteen days (patient was discharged) [1] . Electrocardiographic-triggered CTA (GE Healthcare, Milwaukee, WI) was performed at least twice during the acute phase (once on admission and once before discharge) in patient without disease progression and with well-controlled blood pressure, heart rate and pain; in eventful cases (uncontrollable back pain combined with hemodynamic instability), CTA examinations were adjusted accordingly[1] . The patients were followed clinically according to standard surveillance protocols [1] [15-17] . During the follow-up, CTA was also performed at 1, 3, 6, and 12 months and then annually during the extended follow-up. Disease progression was defined as increased pleural effusion, hematoma thickening (thickness ≥10 mm), development of an aortic pseudoaneurysm, aortic dissection or signs of aortic rupture. Under the following situations, the patients would receive TEVAR treatment: during the acute phase, the expansion of the IMH and the development of pseudoaneurysms despite medical therapy, the disruption of intimal tears on CTA examinations with contrast enhancement, and signs of aortic rupture (uncontrollable back pain combined with a precipitous decrease in blood pressure); and during the chronic phase, the development of aortic dissection, the rapid growth of the ULP or aortic diameters (>5 mm/year), maximum aorta diameter > 55 mm, or signs of aortic rupture[1] . The diameter of the stent graft was based on the diameter of the proximal attachment site with no more than a 10% oversize. At least 1 week of medical therapy (if possible) was employed to provide the initially fragile acute-stage membrane with time to stabilize and become more fibrotic than it was before TEVAR [15] . Preoperative or concomitant arch reconstructive methods were also applied, including in situ laser fenestration technology, a sequential debranching procedure and the chimney technique.