Short-term results in canines of novel stent-graft design for chimney technique in TEVAR

Introduction:Parallel stent-stent grafting is a major endovascular technique used to preserve the supra-aortic branches during thoracic endovascular aortic repair(TEVAR)of aortic pathologies involving the aortic arch.The short-and mid-term results of this technique are satisfactory;however,endoleak remains a major concern.Thus,here we designed a new chimney stent-graft to decrease the endoleak rate.Aim:To testify the feasibility and safety of the new chimney stent-graft system in a canine model.Material and methods:Six Labrador retrievers were used.Pre-operative data were collected and all operations were performed under general anesthesia.The main and chimney stent-grafts were implanted through the abdominal aorta and left subclavian artery approaches,respectively.Completion digital subtraction angiography(DSA)was performed to confirm the immediate outcomes.All dogs were fed separately for 6 months and sacrificed after aortic angiography.The thoracic aorta and the main and chimney stent-grafts were harvested for histopathologic examination.Results:No complications were found in follow-up DSA.All branch arteries were patent.In?ammatory responses were observed around the stent-grafts in 3 experimental animals,and slight hyperplasia was observed in the surrounding tissues compared with the normal vessels.There was no mural thrombus in the stent,endothelial cells were noted on the inner surface of the stent,and thrombus was formed in the outer skirt and gutter area.The histopathologic examinations revealed similar results to those of gross necropsy observations.Conclusions:This study demonstrated the feasibility and safety of the Longuette stent-graft and the first to report a revised stent-graft specific for chimney technique.

Outcomes of Chimney and/or Periscope Techniques in the Endovascular Management of Complex Aortic Pathologies

Background：The chimney/periscope technique has been used to address complex aortic pathologies.This study aimed to report the outcomes and experiences of chimney and/or periscope grafts （CPGs） used in the endovascular management of complex aortic pathologies.Methods：Twenty-two patients with complex aortic pathologies were retrospectively studied from January 2013 to August 2016 in two vascular centers of teaching hospitals.All patients were diagnosed using computed tomography angiography （CTA）.The patients were followed up at postoperative 1,3,6,and 12 months and yearly thereafter with X-ray,ultrasound,and/or CTA.Results：Twenty-two cases （17 males;mean age 60.7 ＆#177; 16.3 years） with complex aortic pathologies were analyzed.Nineteen patients underwent CPGs only,and the other three cases underwent the simultaneous implantation of chimney/periscope and fenestrated/scallop grafts.Twenty-six arteries were managed with forty CPGs during the procedures.Complete angiographies revealed two Type Ⅰ endoleaks,one Type Ⅲ endoleak,and one Type Ⅳ endoleak.Other intraoperative complications included brachial thrombosis,external iliac artery rupture,and left renal stenosis.The 30-day mortality was 0.The mean follow-up was 26.1 ＆#177; 10.1 months with a range of 2-39 months.During the follow-up,two Type Ⅰ endoleaks and one Type Ⅳ endoleak were observed.One right renal stent occlusion occurred in the 5th month and turned patent after reintervention.Three patients died during the follow-up,one due to an aneurysm rupture as a Type Ⅰ endoleak,and two due to myocardial infarction.The instant technical success was 96%.The primary and secondary patencies were 92%and 96%,respectively.The overall survival rates were 95%,84%,and 84% at 12,24,and 36 months,respectively.Stent migration was not observed in any patient.Conclusions：Chimney/periscope techniques could be used to tackle complex aortic pathologies,but the indications must be strictly controlled,and additional experiences are required.

Combined fenestrated/chimney thoracic endovascular repair for the treatment of blunt traumatic aortic injury:A case report

Blunt traumatic thoracic aortic injury(BTAI)is an extremely serious medical condition with a high rate of associated mortality.Recent advances in techniques such as thoracic endovascular repair offer new opportunities to manage the critical BTAI patients in an efficacious yet less invasive manner.A 65 year-old-male suffered from multiple injuries after a fall,including BTAI in the aortic arch,which resulted in dissection of the descending thoracic-abdominal aorta and iliac artery,development of an intimal flap in the left common carotid artery,and dissection of the left subclavian artery.Based on the imaging information of this patient and our clinical experience,the combined treatment of fenestrated thoracic endovascular repair and a chimney technique was immediately planned to fully repair these dissections and moreover prevent further dissection of the branching vessels,additionally to ensure sufficient blood flow in the left subclavian artery and left common carotid artery.The intervention yielded satisfactory early outcomes.Follow-up assessment at six months reported no symptoms or complications associated with the stent-graft.Computed tomography angiography further confirmed adequate stent-graft coverage of the aortic injury.

Endovascular Management of Aortic Arch Diseases:Current Status and Future Trends

Treatment of aortic arch(AA)diseases is challenging for surgeons.Conventional open surgery remains the“gold standard”but is associated with significant morbidity and mortality despite improvements in techniques.In the last 2 decades,thoracic endovascular aortic repair(TEVAR)has become the first-line treatment for diseases of the descending aorta,and its indications have expanded gradually.Various strategies have been proposed to preserve supra-aortic branches in TEVAR:hybrid technique,chimney technique,fenestration technique(including custom-made fenestrated or“scalloped”stent grafts,in situ fenestration,and physician-modified fenestration),and branched stent grafts.Though acceptable outcomes of endovascular aortic repair have been documented,the evidence regarding its long-term safety and efficacy is lacking,and concerns remain about the risk of cerebrovascular events,retrograde type-A dissection,endoleaks,and branch occlusion.This review discusses the current status and progress of endovascular repair of the AA,and looks toward future trends.We believe that multidisciplinary collaboration of a“HENDO”team(professionals in hybrid repair,endovascular repair,open surgery,cardiovascular anesthesia,and genetics)is essential for future repair of the AA to provide the optimal treatment.