DISCUSSION
We recommend using the classification method mentioned above for evaluation. It was more accurate to measure the volume of the descending aorta with three-dimensional reconstruction technology than to measure the maximum diameter and area because the morphological changes of the aortic dissection can be monitored.
To prevent negative remodeling, the number of FL exits should be reduced [9]. Aortic remodeling was related to a persistent FL with partial or complete thrombosis in 90% of cases [10]. The FL of the descending aorta was more prone to thrombosis than the abdomen, due to the blood supply of the internal organs artery entering through the abdomen FL, which preventing the closure of the FL [11]. But it would not cause paraplegia or death by elongate the FET to increase the coverage, and it could promote larger thrombus in the distal FL of the descending aorta contrary[12]. Due to increased FL thrombosis, the extended FET strategy was better at avoiding negative remodeling than standard FET [13]. However, the patent abdominal aorta FL without the coverage of FET may require a second-stage intervention operation [14]. Thus, the ability to accurately identify the expansion of the lumen had a great significance, because the wrong classification may underestimate the rate of FL expansion, which may lead to an increased risk of rupture [7].
Kozlov et al[13]. reported the incident of SCI was 0%, and the ratio of non-negative remodeling that distant landed on Th9 was 67.5% in the short FET group and that distal landed on the L1 was 80% in the long FET group. Similarly, Hoffman et al [15]. reported that choosing a distal landing zone at Th10 to Th12 was safe for SCI in the FET procedure of ATAAD. They performed a more extensive repair of the dissected aorta and blocked the FL clearly in the first procedure. Consequently, we suggest that the landing position on Th8 to Th9 in the long FET group could indeed promote the non-negative remodeling of the descending aorta, and the proportion of positive remodeling in the long FET group was significantly higher than that in the short FET group.
In summary, our classification method can more detailed and accurately evaluate the remodeling results of the descending aorta for measuring the volume. Long FET can be used to treat patients with ATAAD to obtain acceptable remodeling of the descending aorta after measuring the aortic volume. The use of three-dimensional reconstruction technology to establish aortic models can effectively study the morphological changes of the aorta. Compared with the diameter measurement method, volumetric measurement methods can provide more precise evidence for assessing postoperative aortic remodeling.