On April 23, 2024 local time in London, at a meeting, Professor Fu Weiguo from Zhongshan Hospital affiliated to Fudan University shared the latest research progress of the Fabulous® thoracic aortic stent system jointly developed by the team and Hangzhou Weiqiang Medical Technology Co., Ltd., which is specially designed for aortic dissection. It is reported that the stent has been approved by the National Medical Products Administration (NMPA) for marketing.

Post-marketing retrospective study

Research Methods:

It is planned to collect 260 cases in eight centres starting in August 2022. So far, 44 patients with thoracic aortic dissection have been enrolled in two centers. Of these, 77% were in the acute phase, 16% in the subacute phase, and 7% in the chronic phase.

Aortic remodeling

Compared with the preoperative period, the naïve cavity was significantly enlarged at 7 days after surgery, and the expansion rate was 38%. Among them, the minimum diameter of the true lumen was 0 before surgery in 4 patients, and the true lumen was opened after stent implantation and blood flow was restored. In addition, the prosthetic cavity was reduced by 42% at 7 days after surgery and 78% at 3 months after surgery. The Fabulous® thoracic aortic stent system has been shown to have good long-term results, and the true cavity can be continuously expanded. With the progress of the study, it can be seen that at different follow-up nodes, the true cavity is expanding and the false cavity is shrinking.

Table 1. Aortic remodeling – diameter

Figure 2. True lumen, false lumen, and aortic truncus diameters

The false lumen has a high proportion of complete thrombosis

The investigator evaluates the presence of false lumen thrombosis based on CTA results. Most patients do not have intraoperative thrombosis in the pseudoluminal preoperatively. Three patients had complete thrombosis of the false cavity before surgery, and the false cavity shrank or disappeared completely after stent implantation. It is worth mentioning that the rate of complete thrombosis of the false lumen was 52% at 7 days after surgery and increased to 87.5% at 30 days after surgery. Compared to preoperatively, it increased to 80% at 3 months postoperatively. It can be seen that the Fabulous® thoracic aortic stent system has a significant effect on promoting pseudoluminal thrombosis.

Table 2. The false lumen has a high proportion of complete thrombosis

Based on previous TEVAR literature data [1], the rate of complete thrombosis was 46 percent, with a mean follow-up of 49 months. The complete thrombosis rate of the Fabulous® thoracic aortic stent system was 80% at 3 months postoperatively. Compared with TEVAR, the Fabulous® thoracic aortic stent system has a higher rate of false lumen thrombosis, which may be related to its design of a stent graft combined with a bare stent.

Table 3. Comparison with previous literature

Results of 1 month postoperative retrospective study showed that® compared with similar products [2], the rates of visceral ischemia, paraplegia and lower limb paralysis within 1 month after surgery were lower than those of similar products.

Table 4. Compare with similar products

As can be seen from Table 5, the false lumen complete thrombosis rate of the Fabulous® thoracic aortic stent system at 7 days, 1 month and 6 months after surgery is significantly higher than that of similar products. It can be seen that the Fabulous® thoracic aortic stent system is better than the international average of similar products in promoting complete thrombosis of the false lumen.

Table 5. Results were followed up at 7 days, 1 month, and 6 months

Case sharing

Medical history

This is one patient with acute type B dissection admitted to our hospital, with a wide range of dissection, stenosis of the true cavity, and obvious symptoms of lower limb ischemia. 3 days ago, chest and back pain suddenly occurred, and the blood pressure was controlled by the hospital and the pain was relieved. The patient developed numbness in the lower limbs, and the follow-up CT scan showed the progress of the dissection, so he was transferred to our hospital.

Surgical procedure

Surgical procedure (1): Immediately after admission, the angiography showed that there was no obvious blood flow in the right iliac artery, the blood flow in the left iliac artery was slow, and part of the abdominal aorta segment was missing.

Surgical procedure (2): After the first stent graft was implanted, the true cavity of the distal visceral area was not opened, and the abdominal aortic segment was still significantly narrowed.

Surgical procedure (3): The first bare stent was implanted, and the true cavity of the distal visceral area and the distal abdominal aorta were still stenosis. Therefore, it was decided to implant a second bare stent in the transvisal area. After the implantation of the second bare stent, the blood supply to the true lumen in the visceral area was restored, the foot temperature was restored, and the femoral artery and dorsalis pedis artery pulsate.

Preoperative versus postoperative CTA

Right renal artery ischemia before surgery and restoration of blood supply after surgery. Postoperative CTA showed partial thrombosis of the false lumen and patency of the stent.

Postoperative CTA

The true lumen of the stent segment was dilated, and the blood supply to the visceral area was well restored.

Summary

The Fabulous® stent is a stent system specially designed for aortic dissection, and its false lumen complete thrombosis rate is higher than that of similar TEVAR products. Post-marketing clinical studies have preliminarily proved that Fabulous® thoracic aortic stent does not affect the blood supply of splanchnic branch arteries, and the incidence of paraplegia and lower limb ischemia is lower than that of similar products. For patients with extensive dissection, special attention should be paid to the dilation of the distal true lumen after stent implantation, especially the dilation of the visceral true lumen. If the distal true lumen is not dilated well and the visceral ischemia does not improve after stent implantation, a second or even third bare stent should be implanted.

References

[1] Hofferberth SC, Newcomb AE, Yii MY, et al. Combined proximal stent grafting plus distal bare metal stenting for management of aortic dissection: Superior to standard endovascular repair? J Thorac Cardiovasc Surg. 2012 Oct;144(4):956-62. [2] Lombardi JV, Gleason TG, Panneton JM, et al. STABLE II clinical trial on endovascular treatment of acute, complicated type B aortic dissection with a composite device design. J Vasc Surg. 2020 Apr;71(4):1077-1087.e2.