Long-Term Outcomes of Chronic Type B Aortic Dissection Treated by Thoracic Endovascular Aortic Repair

Abstract

Background The treatment of chronic type B aortic dissection by thoracic endovascular aortic repair has some challenges, and its long-term outcomes remain unclear. This study aimed to analyze the 5-year clinical outcomes of thoracic endovascular aortic repair of chronic type B aortic dissection, compare the differences between patients with and without adverse aortic events (AAEs), and identify risk factors for AAEs. Methods and Results Patients who underwent thoracic endovascular aortic repair of chronic type B aortic dissection from January 2009 to June 2017 were retrospectively enrolled. The primary end points were AAEs, including aorta-related death, procedural complications, and disease progression requiring reintervention. Clinical outcomes were described at the 5-year follow-up visit. The secondary end point was the comparison of the results between patients with and without AAEs. Univariable and multivariable logistic analyses were used to identify potential risk factors for AAEs. A total of 214 patients were enrolled. AAEs occurred in 46 (21.5%) patients. Compared with patients without AAEs, those with AAEs had higher rates of residual type A aortic dissection (26.1% versus 4.2%, P<0.001) and aortic diameter ≥5.5 cm (69.6% versus 11.3%, P<0.001), and a lower rate of complete false lumen thrombosis (23.9% versus 89.9%, P<0.001). Meanwhile, the median interval from symptom onset to intervention was longer in patients with AAEs (26 months versus 12 months, P=0.004). Partial or no false lumen thrombosis (adjusted odds ratio [AOR], 14.71 [95% CI, 5.67-38.14; P<0.001]) and aortic diameter ≥5.5 cm (AOR, 10.16 [95% CI, 3.86-26.73; P<0.001]) were identified as independent risk factors for AAEs. Conclusions While thoracic endovascular aortic repair of chronic type B aortic dissection might be challenging in some cases, its long-term outcomes appeared promising as this treatment was effective in preventing catastrophic aortic events. Patients with AAEs showed higher rates of residual type A aortic dissection and aortic diameter ≥5.5 cm, a lower rate of complete false lumen thrombosis, and a longer median interval from symptom onset to intervention. Failure of complete false lumen thrombosis and an aortic diameter ≥5.5 cm were predictors of AAEs.

Keywords: aortic remodeling; chronic type B aortic dissection; long‐term outcomes; thoracic endovascular aortic repair.

Figure 1. Illustration of 2 levels of measurement.

Level A, the maximal aortic diameter; Level B, the distal end of the stent graft.

Figure 2. The annual diameter changes of the true lumen and false lumen at 2 levels.

A, At level A, the diameter of true lumen increased by 9.0±2.3, 2.7±1.0, 1.0±0.2, 0.5±0.1, and 0.6±0.1 mm, and the diameter of false lumen decreased by 7.1±1.1, 3.0±0.7, 1.5±0.4, 0.7±0.1, and 0.5±0.1 mm at 1, 2, 3, 4, 5 years after endovascular repair. B, At level B, the diameter of true lumen increased by 6.9±1.3, 2.5±0.5, 1.1±0.2, 0.6±0.1, and 0.5±0.1 mm, and the diameter of false lumen decreased by 3.8±0.9, 1.0±0.3, 0.6±0.1, 0.5±0.1, and 0.4±0.1 mm at 1, 2, 3, 4, and 5 years after endovascular repair.

Figure 3. The occurrence of stent‐induced new entry.

The chronic type B aortic dissection was confirmed in an 82‐year‐old man (A), and he underwent endovascular repair by a stent graft (38*200 mm, Zenith). The false lumen was completely thrombosed at 5 months (B), as well as 12 months (C). However, the distal stent‐induced new entry was observed at 24 months (D), and a stent graft (38*200 mm. Zenith) was deployed to seal the distal stent‐induced new entry. The aortic remodeling was satisfactory at 6 months (E) and 24 months (F) after reintervention.

Figure 4. The occurrence of retrograde type A aortic dissection. A 74‐year‐old man complained of chest pain for 2 years.

The computed tomography show aortic dissection with entry tear in the distal to the left subclavian artery (A) and the false lumen was patent (B). A stent graft (36*200 mm, Valiant Captivia) was deployed. However, he suffered acute refractory chest pain at 26 days, and the computed tomography showed retrograde type A aortic dissection (C) and the false lumen was partially thrombosed (D). Hence, he underwent ascending aorta and aortic arch replacement and survived.

Figure 5. The cumulative survival and freedom from reintervention rates calculated by Kaplan–Meier analysis.

A, The 5‐year and 10‐year cumulative survival rates were 86.6% (95% CI, 81.2%–90.5%) and 79.0% (95% CI, 71.7%–84.5%). B, The 5‐year and 10‐year freedom from reintervention rates were 95.3% (95% CI, 91.5%–97.5%) and 89.9% (95% CI, 84.6%–93.5%).