Open surgery remains the treatment of choice for ascending aortic disease. Its associated morbidity and mortality in emergency and complex cases, together with the fact that almost 20% of patients are considered inoperable, provide a rationale for exploring less invasive options. However, the aortic valve, coronary arteries, supra-aortic vessels, ascending aortic morphology, high pulsatility and lack of commercially available dedicated endografts currently make isolated endovascular treatment of this aortic segment challenging.
NAVIGATE is a retrospective multicentre registry covering 2023–2025. It includes high-risk or inoperable patients with isolated ascending aortic disease. Requirements include a sealing zone ≥15 mm, 10–20% oversizing, a distance of ≥10–15 mm from the coronary ostia and no aortic root involvement. ECG-gated CT angiography is performed before the procedure, before discharge and at 30 days. Thirty-day outcomes are assessed using descriptive statistics in what remains a small sample.
Eight patients were included: median age was 80 years and median EuroSCORE II was 24%; seven had undergone previous cardiac surgery, seven had pseudoaneurysms, including three mycotic lesions, and one had an acute type II dissection. Nexus® modules measuring 40, 55 and 70 mm in length and 36 and 40 mm in diameter were implanted transfemorally under rapid ventricular pacing. Two patients required an additional stent-graft to obtain a proximal seal. Median intensive care unit stay was one day and total postoperative hospital stay was five days. Technical success was achieved in every case. At 30 days, there were no deaths, strokes, type I or III endoleaks, tamponade, valvular or coronary dysfunction, or conversions to open aortic surgery. One patient experienced bleeding at the percutaneous femoral access site, which required conversion to surgical exposure during the procedure. During a median follow-up of 15 months, there was one unrelated death and one death from persistent infection in a patient with a mycotic pseudoaneurysm. An open conversion was also performed, with explantation of the Nexus® endograft and replacement with a homograft. The authors therefore conclude that this Nexus® platform may offer a useful therapeutic option for isolated endovascular zone 0 repair of suitable focal lesions in patients who are not candidates for open surgery, although further studies and larger series are needed.
COMMENTARY:
The Nexus® ascending aortic module (Endospan Ltd., Herzliya®, Israel) has several distinctive features. It is an off-the-shelf rather than a custom-made module, allowing rapid availability and even local stocking. Its delivery system is precurved to facilitate orientation and has a 20F outer profile. The nominal endograft lengths of 40, 55 and 70 mm are measured along the centreline. Because the stent-graft is asymmetric, 15 mm must be added to or subtracted from the nominal length to calculate its length along the greater or lesser curvature, respectively. Correct rotational orientation is therefore essential, with radiopaque marker B facing the greater curvature and fluoroscopy set to an appropriate working projection. There is a small fabric-free distal notch along the greater curvature. Three nominal diameters are available: 36, 40 and 43 mm. However, the distal 24 mm always has a diameter of 36 mm, as this segment was originally designed to seal within the 30-mm docking sleeve of the aortic arch–brachiocephalic component.
As the article partly acknowledges, these procedures should include ECG-gated CT angiography for planning and surveillance, transoesophageal echocardiography and cerebral oximetry for intraoperative monitoring, and immediate access to cardiopulmonary bypass, TAVI or brachiocephalic artery stenting if required.
NAVIGATE reduced the required sealing length to 15 mm, whereas the Nexus® instructions for use specify 30 mm. This seems reasonable for pseudoaneurysms, which accounted for seven of the eight cases and usually involve only part of the aortic circumference. A shorter sealing zone may therefore be acceptable, particularly given the high surgical risk, the minimally invasive nature of the procedure and the limited lengths available between adjacent anatomical structures. The early outcomes and 15-month follow-up in NAVIGATE appear to support this approach.
Endovascular treatment as a bridge to open surgery may be particularly valuable, as illustrated by case 7, a patient with a mycotic pseudoaneurysm who underwent surgery after completing antibiotic treatment. In selected cases, this strategy may make re-sternotomy safer and allow definitive treatment to be deferred while the patient’s condition is optimised. Numerous published cases describe definitive endovascular treatment combined with antibiotics for mycotic disease in different aortic segments. In this series, case 5 had a favourable outcome, whereas case 6 failed because of persistent infection, with death at four months.
This encouraging initial experience, with excellent early outcomes in highly selected patients with focal lesions and high surgical risk, makes a case for keeping Nexus® ascending modules in stock. It should also broaden our view of ascending aortic endovascular treatment as an evolving part of present-day practice. Technological adaptations, including new devices and endo-Bentall procedures, are likely to overcome progressively more anatomical obstacles, as has happened in other aortic segments. Cardiovascular surgeons should therefore be trained in these techniques and have them available around the clock, so that patients can be offered the option considered most appropriate without being constrained by access to a single treatment modality.
REFERENCE:
Mosquera VX, Ferreiro A, Abisi S, Riera L, Maßmann A, Pherwani A, et al. The NAVIGATE Registry: Early Endovascular Repair of the Ascending Aorta With the Nexus Ascending Module. Interdiscip Cardiovasc Thorac Surg. 2026 Jun 9;41(6):ivag128. doi: 10.1093/icvts/ivag128.
