Safety and efficacy of a novel, fenestrated aortic arch stent graft with a preloaded catheter for supraaortic arch vessels: an experimental study in Swine

Animal study on adjustable pre fenestration aortic stent graft

OBJECTIVES

To isolate aortic arch pathologies and keep the branches superior in arch patent, it always need physicians to do in-vivo fenestration or in-situ fenestration when performing the thoracic endovascular aortic repair (TEVAR). However, both of those fenestration techniques need structure modification of the stent-graft, which may affect their long-term stability. We designed an adjustable pre-fenestration aortic stent-graft to treat pathologies in this area and obtained a patent branch arteries. This study used this new designed stent-graft to perform fenestrated-TEVAR (f-TEVAR) in canine aorta. This study aims to identify its feasibility and safety through animal experiments, which might provide preliminary data for potential human implantation.

METHODS

A total of 8 Labrador Retrievers were underwent f-TEVAR by using the new devices. Digital subtraction angiography was performed before and after f-TEVAR to evaluate the success of the procedures. All the canines were divided into a 4-week group (feeding for 4 weeks after operation) and a 12-week group (feeding for 12 weeks after operation). Computed tomography angiography (CTA) were performed before euthanasia.

RESULTS

The success rate of operation was 100%. During the operation, there was no accident of major bleeding or failure to be released by fenestration. Adjustable fenestration worked well. No stent-graft migration was found in CTA at 4 weeks and 12 weeks after the operation. All branch arteries kept by the adjustable fenestration were patent.

CONCLUSIONS

The result of feasibility and safety of the new designed adjustable pre-fenestration aortic stent-graft in f-TEVAR of canine is acceptable. This study provides a reference for further optimization of this stent and human f-TEVAR implantation involving aortic arch lesions.

Safety and Feasibility Study of a Novel Stent-Graft for Thoracic Endovascular Aortic Repair: a Canine Model Experiment

Objective

To evaluate the safety and feasibility of a novel stent-graft for thoracic endovascular aortic repair (TEVAR) in a canine model, 9 adult hybrid dogs were used for the experiment.

Methods

All animals were implanted with a novel thoracic aortic stent-graft via femoral artery. Blood sample was collected at pre-operation and 1, 2, 4, 8 and 12 weeks after implantation for hematological examination. Moreover, tissues from randomly selected 4 dogs were subjected to histopathological analysis with the optical microscope after stent-grafts were implanted for 3, 6, 9, and 12 months respectively. The experimental period lasted for more than 2 years.

Results

A total of 9 stent-grafts were successfully implanted in the canine thoracic aortas and no migration or deformation occurred. Related indicators of blood routine, inflammatory factors, and immunology changes were not significantly (P>0.05), except the white blood cell (WBC) counts in the first week. Moreover, abnormal morphology was not found in all thoracic aortas via histopathological examination. Additionally, all stent-grafts were patent and did not migrate, and there was no thrombus in the lumens of stent-grafts.

Conclusion

The novel thoracic aortic stent-graft made in China was safe and feasible for thoracic endovascular aortic repair in a canine model.

Safety and Efficacy of an Aortic Arch Stent Graft with Window-Shaped Fenestration for Supra-Aortic Arch Vessels: an Experimental Study in Swine

Background and Objectives

Thoracic endovascular aortic repair exhibits limitations in cases where the aortic pathology involves the aortic arch. We had already developed a fenestrated aortic stent graft (FASG) with a preloaded catheter for aortic pathology involving the aortic arch. FASG was suitable for elective cases.

Materials and Methods

An aortic arch stent graft with a window-shaped fenestration (FASG-W) for supra-aortic arch vessels is suitable for emergent cases. This study aims to test a FASG-W for supra-aortic arch vessels and to perform a preclinical study in swine to evaluate the safety and efficacy of this device. Six FASG-Ws with 1 preloaded catheter were advanced through the iliac artery in 6 swine. The presence of endoleak and the patency and deformity of the grafts were examined with computed tomography (CT) at 4 weeks postoperatively. A postmortem examination was performed at 8 weeks. The mean procedure time for FASG-W was 27.15±4.02 minutes. The mean time for the selection of the right carotid artery was 5.72±0.72 minutes.

Results

Major adverse events were not observed in any of the 6 pigs who survived for 8 weeks. For the FASG-W, no endoleaks, no disconnection, and no occlusion of the stent grafts were observed in the CT findings or the postmortem gross findings.

Conclusion

The procedure with the FASG-W was able to be performed safely in a relatively short procedure time and involved an easy technique. The FASG-W was found to be safe and convenient for use in this preclinical study of swine.