Outcomes and Morphologic Changes of Immediate Type Ia Endoleak following Endovascular Repair of Acute Type B Aortic Dissection

Abstract

The clinical significance of immediate type Ia endoleaks after thoracic endovascular aortic repair (TEVAR) for aneurysms has been described in detail. However, this phenomenon is still controversial in TEVAR patients treated for acute type B aortic dissection. A single-institution study was conducted in 81 prospectively evaluated patients treated between January 2012 and June 2012 for acute type B aortic dissection. Preoperative and postoperative computed tomography angiography (CTA) images were analyzed using 3-dimensional reconstruction to measure the areas and indices of the true lumen, false lumen, and total aorta in the proximal, middle, and distal descending thoracic aorta. Data were analyzed and compared between the 2 groups of patients, with and without immediate type Ia endoleaks. The average follow-up period was 12 months (range 10-13 months) after the procedure. TEVAR was successfully performed in all patients (mean age 53 years; 86% men). Thirty-six of the 81 patients were diagnosed with complicated type B dissection, including persistent pain (19/36, 52.7%), refractory hypertension (4/36, 11.1%), and end-organ ischemia (13/36, 36.1%). Of all the patients, 37 (45.7%) were diagnosed with immediate type Ia endoleaks. The differences between the 30-day and 1-year all-cause mortality rates between the 2 groups were nonsignificant (13.5% vs. 2.2%, P = 0.08; 16.2% vs. 4.5%, P = 0.13). No stroke or paraplegia occurred during the follow-up. Reintervention was performed in 2 patients for delayed type I endoleaks in the group without immediate type Ia endoleaks. Pre- and postoperative CTA images were available for analysis in 54 patients. Among them, 24 patients had type Ia endoleaks. Patients with immediate type Ia endoleaks had a significantly larger preoperative distal false lumen area (498 ± 274 vs. 284 ± 213 mm(2), P = 0.02) and a larger distal aortic area (759 ± 275 vs. 624 ± 185 mm(2), P = 0.03). The 1-year follow-up CTA demonstrated significantly smaller true lumen indices and larger false lumen areas and false lumen indices in the proximal, middle, and distal sections in patients with immediate type Ia endoleaks. Differences in the postoperative morphological changes of the whole descending thoracic aorta were significant between the 2 groups, with the maximum area and the proximal, middle, and distal regions involved. The occurrence of endoleaks and the rates of postoperative false lumen thrombosis throughout the length of stent grafts were not significant at 1-year follow-up. The majority of immediate type Ia endoleaks following TEVAR in acute type B aortic dissections could seal spontaneously, without additional procedures needed. However, the appearance of such complications could be a risk factor of poorer aortic remodeling. Careful surveillance is recommended more frequently in patients with immediate type Ia endoleaks.