The Mini-Cross Prefenestration for Endovascular Repair of Aortic Arch Pathologies

Abstract

Objective: To examine the feasibility, integrity, efficacy, and safety of endovascular repair of the aortic arch pathologies with the mini-cross prefenestration (MCPF) on stent grafts. Methods: First, to prove the feasibility of the MCPF, an in-vitro prefenestration experiment was conducted. Second, to examine the integrity of the MCPF stent grafts, a fatigue test was conducted. Then, the membranes and metal structures of stent grafts were examined by light microscopy and scanning electron microscopy (SEM). Third, a clinical experiment was conducted to investigate the efficacy and safety of this novel technique (ClinicalTrials.gov Identifier: NCT04544579). Results: All the 12 branch stents were successfully implanted and flared in vitro. After the fatigue test stimulating a 5-year cardiac cycle, no obvious disintegration or fracture was found in light microscopy or SEM. From December 2017 to February 2020, 26 patients with left subclavian arteries and/or left common carotid arteries involved received the novel technique. The endovascular repair with the MCPF was successfully performed on all the 26 (100%) patients. Eighteen (69.2%) patients underwent the reconstruction of the left subclavian artery (LSCA) only. The fenestrations of both the LSCA and left common carotid artery (LCCA) were conducted in 8 (30.8%) patients. Median operative time was 120 [interquartile range (IQR), 95-137.5] min and median revascularization time of the LSCA and LCCA was 30.5 (IQR, 22.8-42.0) s and 20.0 (IQR, 18.0-32.0) s separately. During the median follow-up duration of 38.9 (range, 18.8-44.2) months, one case needed an open surgery because of retrograde type A aortic dissection 3 months after implantation and no other complications or mortality occurred. The maximum aortic diameters were significantly decreased in patients with thoracic aortic dissection and thoracic aortic aneurysm (p < 0.05). Conclusion: The existing evidence demonstrated the safety, rapid branch artery revascularization, and positive aortic remodeling of the novel technique. Long-term observation is warranted to prove the durability.

Keywords: aortic arch pathologies; branch artery; in vitro fenestration; thoracic aortic aneurysm; thoracic aortic dissection; thoracic endovascular aortic repair.

Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Copyright © 2022 Pei, Zhu, Xiao, Zhou and Jing.

Figures

Figure 1

In-vitro experiment on the MCPF stent grafts in silicone models. (A) Release of the Valiant Stent Graft (diameter 34 mm and length 150 mm) with a 5 × 5 mm cross prefenestration (black square). (B) The hole of the fenestration is suitable to come through for an 8 Fr catheter delivery system (Fluency Plus Stent, diameter 80 mm and length 80 mm). (C) Release of the branch stent. (D) Top view of the branch stent after release. The hole was slightly expanded by the self-expanding force (white arrow). (E) The stent graft was flared with a peripheral angioplasty balloon at 4 atmospheres (Bard Mustang, diameter 10 mm and length 40 mm) (black arrows). (F) The stent graft was completely flared at 6 atmospheres (blue arrows). MCPF, mini-cross prefenestration.

Figure 2

In-vitro fatigue experiment on the MCPF stent grafts in silicone models. (A) The diagram of the silicone model. (B) The main and branch stent grafts were implanted into the silicone model. (C) After stent grafts implantation, all the silicone models were installed into the fatigue test machine to stimulate the relative movement of the aorta and branch artery with the aortic pulsation. (D) The parameters were automatically controlled by the computer, in which the temperature was 37°C, the average systolic/diastolic water pressure was 130/80 mm Hg, and the beating rate was 1,000 bpm. MCPF, mini-cross prefenestration.

Figure 3

Fluoroscopic demonstration of the fenestrated stent graft delivery and engagement. (A) Morphological feature of aortic dissection through the digital subtraction angiography. (B) Delivery and advancing of the main stent graft into the proper landing zone. A traction guidewire was established through the left subclavian artery (LSCA) (white arrows). An angioplasty balloon catheter was prepared for the expansion of the fenestration (yellow arrows). (C) The main stent graft was released and the LSCA was temporarily covered. The traction guidewire was still in the stent graft (blue arrow). (D) Angioplasty of the LSCA through the guidewire from left brachial access (green arrows). The duration from coverage of the LSCA and revascularization was 36 s (red arrows, 14:14:34–14:15:10). (E) Deployment and engagement of the LSCA branch stent graft. (F) Final aortogram demonstrating patent arch branches and exclusion of the false lumen.

Figure 4

Morphological analysis of main and branch stent grafts after a fatigue test. (A–D) The connections of main and branch stent grafts were estimated by light microscopy. (E–H) The fabrics around the fenestrations on the main stent grafts were estimated by light microscopy. (I–L) The fabrics around the fenestrations on the main stent grafts were estimated by scanning electron microscopy. The magnification was 100×. *, the inner side of fenestrations. (M–P) The membrane and metal structures of branch stent grafts were examined by scanning electron microscopy. The magnification was 100×.

Figure 5

Patency of the LSCA was followed-up in a patient receiving the MCPF technique. (A) Preoperative CTA showed that a patient suffered from thoracic aortic dissection, which involved the LSCA. (B) Intraoperative aortogram demonstrated that the LSCA was revascularized and false lumen was excluded. (C) Before discharge, CTA was conducted to confirm the patency of the LSCA and exclusion of false lumen. (D) CTA at follow-up of 6 months. (E) CTA at follow-up of 12 months. (F) CTA at follow-up of 24 months. LSCA, left subclavian artery; MCPF, mini-cross prefenestration; CTA, CT angiography.

Figure 6

Aortic remodeling and proximal thrombosis of false lumen/aneurysmal sac at follow-up. (A) The changes of maximum diameters of TAD before the operation, at 6-month, 12-month, and the last follow-up. (B) The changes of maximum diameters of TAA before the operation, at 6-month, 12-month, and the last follow-up. (C) The proximal thrombosis of false lumen in TAD (n = 15) before the operation, at 6-month, 12-month, and the last follow-up. One patient suffered from retrograde type A aortic dissection after 3 months and received the total arch replacement. (D) The proximal thrombosis of aneurysmal sac in TAA (n = 11) at 6-month, 12-month, and the last follow-up. *p < 0.05; **p < 0.01; ***p < 0.001. TAD, thoracic aortic dissection; TAA, thoracic aortic aneurysm; FU, follow-up.