Aortic remodeling with frozen elephant trunk technique for Stanford type A aortic dissection using Japanese J-graft open stent graft

Abstract

The frozen elephant trunk (FET) technique allows single-stage extended surgical repair of Stanford type A aortic dissection and has shown promotion of aortic remodeling by maintaining the true lumen flow and facilitating its expansion and by promoting false lumen thrombosis. However, few studies have compared the effectiveness of FET technique, in terms of the downstream aortic remodeling. Between 2005 and 2017, 50 patients underwent total arch replacement for Stanford type A aortic dissection, including that with (n = 22) and without FET technique (n = 28). We compared distal aortic remodeling in patients who underwent total arch replacement with (using a J-Graft open stent graft) or without the technique. The false lumen complete thrombosis rate and the ratio of true lumen area at three levels of the descending aorta were evaluated post operation. In FET group, the diameter and length of the stent graft were 29.0 ± 3.9 mm and 70.9 ± 17.4 mm, respectively. The in-hospital death with and without the FET technique was 0 and 3, respectively, with no late death in both groups. Eight patients (28.6%) only in the non-FET group required additional surgical treatment for downstream aorta. In the FET group, the ratio of true lumen area at the level of bronchial carina and false lumen complete thrombosis rate at the levels of bronchial carina and aortic valve were significantly higher than non-FET group. A more favorable remodeling in the descending aorta was observed in patients who underwent FET associated with a total arch replacement compared to those who underwent total arch replacement alone.

Keywords: Aortic dissection; Aortic remodeling; Frozen elephant trunk.

Fig. 1. a

The evaluated false lumen complete thrombosis rate and the ratio of true lumen area at three levels of bronchial carina (1), aortic valve (2), and diaphragm (3). b The false lumen was not enhanced, and therefore defined as “complete thrombosis.” The ratio of true lumen was 55.8%, which was calculated by dividing the traced area of true lumen (red line circle, 750 mm²) by the traced area of the whole aorta (dotted line circle, 1350 mm²). c The false lumen was enhanced, and therefore defined as patent false lumen. The ratio of true lumen was 17.2% (240/1395 mm²)

Fig. 2

The Kaplan-Meier time-related comparison was used for the freedom from additional surgical treatment after initial TAR in the two groups. The p value was not given because of the difference of follow-up duration and short follow-up of FET group, although Log-rank t-test was made

Fig. 3

CT scan of a patient treated with TAR with FET. Preoperative CT image (a–c), postoperative image before discharge from the hospital (d–f), and at 3 months after the operation (g–i) at the level of bronchial carina (a, d, g), aortic valve (b, e, h), and diaphragm (c, f, i), respectively. Note excellent aortic remodeling of downstream aorta after TAR with FET with the complete thrombosis of false lumen and expanded true lumen at each level

Fig. 4

CT scan of a patient treated with TAR without FET before 2015. Preoperative image (a–c), and postoperative image before discharge from the hospital (d–f) at the level of bronchial carina (a, d), aortic valve (b, e), and diaphragm (c, f), respectively. Note that, although the elephant trunk was inserted in the descending aorta, the false lumen is patent and the true lumen expansion is not observed at each level of downstream aorta