Case report of an endovascular repair of a residual type A dissection using a not CE not FDA-approved Najuta thoracic stent graft system

Preliminary results from an Italian National Registry on the outcomes of the Najuta fenestrated aortic arch endograft

BACKGROUND

Arch pathology represents one of the last frontiers in aortic aneurysm endovascular management. Several companies recently developed dedicated branched and fenestrated endografts specifically designed for the aortic arch, aiming to overcome some of the issues associated with standard thoracic endograft and supra-aortic vessels extra-anatomic debranching. This study aimed to evaluate early outcomes obtained with a custom-made fenestrated endograft approved for thoracic aortic aneurysms exclusion.

METHODS

All consecutive patients treated with the Najuta endograft (Kawasumi Laboratories, Inc, Tokyo, Japan) in Italy were enrolled prospectively and included in the study population. Anatomic characteristics and perioperative data were analyzed retrospectively. Study end points were technical success, 30-day clinical success, overall survival, supra-aortic vessel patency, endoleak, and need for reintervention or surgical conversion.

RESULTS

Between 2018 and 2022, 76 patients received a Najuta endograft in Italy and were enrolled in the study. The median patient age was 72 years (interquartile range, 69-76 years) and 80.3% were male. Most of the patients received treatment for atherosclerotic aneurysms (80.3%); others were treated for postdissection aneurysms (7.9%), penetrating aortic ulcer (9.2%), or type I endoleak correction after previous thoracic endovascular repair (2.6%). Overall, 161 supra-aortic vessels were preserved through a dedicated fenestration. Technical success was achieved in 74 of 76 procedure (97.4%); both failures were associated with endoleak detection at final angiography (one type I and one type III endoleak). Two distal migrations occurred during the implanting procedure. Clinical success at 30 days was 94.7%. Two early reinterventions were needed within 30 days after index procedure: in one case, an aortic false lumen coils embolization was performed, because distal re-entry caused enlargement of the postdissection thoracic aneurysm. The other procedure consisted of a femoral pseudoaneurysm repair. The median follow-up was 7 months (interquartile range, 3-15 months); no supra-aortic vessel occlusions occurred and no patients needed surgical conversion.

CONCLUSIONS

Early results suggest that, in selected patients with aortic arch pathology needing a proximal landing, an endovascular approach with the Najuta system is safe and effective, especially for those at high surgical risk. A strict follow-up with high-quality computed tomography angiography images and eventual evaluation for long-term complications is needed to confirm these initial experience findings.

Alternative management of proximal aortic dissection: concept and application

Open surgery remains the mainstay of treatment for acute type A aortic dissection and should be offered to most patients. However, there are elderly patients in which surgical treatment may be deemed extremely high risk or futile. Endovascular treatment approaches have been applied to a small number of these patients and data are limited to case reports and small series. The application of endovascular therapies to ascending aorta is currently limited by anatomical and technical challenges posed by the dynamic motion of the ascending aorta and the proximity of vital structures to intended landing zones (aortic valve, coronary arteries, and supra-aortic branches) and lack of specially designed endografts to address these issues. While thoracic endovascular aortic repair (TEVAR) has replaced open aortic repair for a suitable lesion in distal aortic dissection, some selected patients with type A aortic dissection at high surgical may be candidates. Hence, there is potential because, in proximal (Stanford type A) dissections, 10-30% of patients are not accepted for surgery, and 30-50% are technically amenable for TEVAR. Recent experience has shown that carefully selected patients with favorable anatomical characteristics may be subject to endovascular stent-graft treatment as a last resort with mixed results. Technical improvement is necessary to offer. satisfactory endovascular options in non-surgical candidates.

Endovascular repair of ascending aorta pseudoaneurysm

We present a case of a 48-year-old female patient with Marfan syndrome and previous open surgeries for Bentall procedure and arch replacement with frozen elephant trunk (FET) technique, who was admitted at our Department with a diagnosis of ascending aorta pseudoaneurysm at the anastomosis-site between composite valve graft and arch prosthesis treated by endovascular procedure because of she was considered to be at high-risk for a third open surgery and for the patient's favorable anatomy for endovascular closure of the pseudoaneurysm. The patient was successfully treated with the positioning of two abdominal cuffs through the left axillary artery. The postoperative course was uneventful and at 2-month follow-up, the patient was free of complications with CT angiogram showing complete endovascular exclusion of the pseudoaneurysm.

Investigating the performance of four specific types of material grafts and their effects on hemodynamic patterns as well as on von Mises stresses in a grafted three-layer aortic model using fluid-structure interaction analysis

One of the important parts of the cardiac system is aorta which is the fundamental channel and supply of oxygenated blood in the body. Diseases of the aorta represent critical cardiovascular bleakness and mortality around the world. This study aims at investigation of hemodynamic parameters in a two-dimensional axisymmetric model of three-layer grafted aorta using fluid-structure interaction (FSI). It assumes that a damaged part of aorta, which may happen as a result of some diseases like aneurysm, dissection and post-stenotic dilatation, is replaced with a biomaterial graft. Four types of grafts materials so-called Polyurethane, Silicone rubber, Polytetrafluoroethylene (PTFE) and Dacron are considered in the present study. The assumption of linear elastic and isotropic material is set for the both aorta's wall and aforementioned grafts. Blood is considered as an incompressible and Newtonian fluid. The results indicate higher displacement in Polyurethane and silicone rubber in comparison with other two. Furthermore, results reveal that blood flow velocity has slightly higher values in PTFE and Dacron grafted models compared to Polyurethane and Silicone rubber ones. Even though there are some differences in hemodynamic patterns in these grafted models, they are not considerable as much as von Mises stresses across the graft-aorta intersections are. This study shows that the types of material grafts play an important role in the amount of stresses particularly at intersections of aorta and graft.

Minimally Invasive Techniques for Total Aortic Arch Reconstruction

The cumulative experience with endovascular aortic repair in the descending thoracic and infrarenal aorta has led to increased interest in endovascular aortic arch reconstruction. Open total arch replacement is a robust operation that can be performed with excellent results. However, it requires cardiopulmonary bypass and circulatory arrest and, therefore, may not be tolerated by all patients. Minimally invasive techniques have been considered as an alternative and include hybrid arch debranching, parallel stent graft deployment in the chimney and snorkel configurations, and complete endovascular branched reconstruction with multi-branched devices. This review discusses the evolving use of endovascular techniques in the management of aortic arch pathology and considers their relevance in an era of safe and durable open aortic arch reconstruction.

Aortic arch aneurysm repair using the Najuta stent graft in a challenging compromised seal zone

We report the case of a 67-year-old patient with an anatomically complex aneurysm of the aortic arch treated by fenestrated thoracic endovascular aortic repair with subclavian-carotid extrathoracic bypass. We used the Najuta thoracic stent graft, which was approved for use in January 2013 in Japan and successfully excluded the aneurysm. Our case shows that the Najuta stent graft procedure is a feasible treatment if open repair is unsuitable for cases of aortic arch aneurysm with a challenging compromised seal zone.

Endovascular Repair of Type A Aortic Dissection: Current Experience and Technical Considerations

Dissection of the ascending aorta, type A aortic dissection (TAAD), represents a surgical emergency with high morbidity and mortality. Current open surgical techniques, although state-of-the-art procedures and having improved outcomes for patients with TAAD over the last decades, confer significant risk of complications and death. Recently, endovascular techniques for repair of both the abdominal and thoracic aorta have gained acceptance within the vascular and cardiovascular surgical communities as a useful tool in select pathologies and patient populations. As development of endovascular technology proceeds ever closer to the aortic valve, thoracic endovascular repair for TAAD deserves special investigation. A comprehensive literature search for studies reporting outcomes of endovascular repair in the ascending aorta was performed. In this review, we compile the worldwide experience of thoracic endovascular repair for TAAD as well as imaging studies for patient selection and the use of hybrid (open plus endovascular) techniques. The authors discuss the remaining challenges that preclude its broader adoption in this role, namely patient selection and device specificity.