Commentary on ‘Endovascular Aneurysm Sealing for Infrarenal Abdominal Aortic Aneurysms: 30 Day Outcomes of 105 Patients in a Single Centre’

Abstract

analysis of 30 day outcome in 105 patients with an abdominal aortic aneurysm (AAA) treated by endovascular aneurysm sealing (EVAS). EVAS is a novel treatment concept for patients with an infrarenal AAA, and is aimed at reducing type II endoleaks and at expanding the options for endovascular repair in that it has been claimed to have the potential to treat more patients with unfriendly anatomy than other devices for EVAR. In this non-consecutive series of predominantly elective patients with 69% having adverse neck anatomy, technical success was achieved in 97%, with four patients having a proximal type I endoleak, which was resolved by Onyx and coil embolization. Thirty day mortality was 1%, one patient suddenly died 18 days post-operatively at home. These excellent results are a reflection of the St George’s Vascular Institute’s (SGVI) wide experience with AAA repair. In their paper, the authors share technical difficulties and complications that were encountered during their learning curve with the device. Of interest, some 62 (59%) of the patients had adjunctive iliac stenting, which seems to be a high proportion, and may have been triggered by the author’s early experience. Three of the first 20 patients were treated post-operatively with additional stents because of >50% stenosis caused by inadequate stent dilatation or kinking. The operative technique was adapted by doing liberal pre-emptive stenting in order to avoid early stent occlusion. Another technical modification was to keep the balloons inflated during polymer curing. Finally, important lessons were learned from the occurrence of two iatrogenic ruptures in patients with narrow and calcified common iliac arteries, which were eventually resolved by insertion of covered stents. The current paper is the first of a series on early outcomes of EVAS that can be expected in the near future. Bockler et al. 2 reported similar good results of EVAS in a multicenter experience, including some patients from SGVI. Mortality was zero out of 171 patients, technical success was 99%. There were five type Ia and four type 1b endoleaks, and 11 (6%) patients had a re-intervention within 30 days, four for device occlusion.The early results of the EVAS Forward Registry (NCT02018744) with 300 patients and the EVAS Forward-IDE (investigational device exemption) in the United States (NCT01726257) with 179 patients are hopefully to be published shortly. It is important to realize that there will be some overlap in patients between the registries and reports of individual centers, and that results will be advertised as being achieved in real world patients. Yet, the results are a representation of real world patients treated in centers of excellence. Is the EVAS system going to change the practice of endovascular aneurysm repair? Although type II endoleaks occur in less than 1% of patients after EVAS, it is known that these have limited clinical significance in the absence of aneurysm growth. In a systematic review including 21,744 patients, a type II endoleak was present in 10.2% after EVAR, with spontaneous resolution in 35.4%. 3 Only 14 patients with an isolated type II endoleak had a ruptured AAA, six of them without aneurysm sac expansion. A more important advantage of EVAS might be the expansion of the indications for endovascular repair in patients with hostile necks, which is clearly illustrated in the paper by Brownrigg et al. and to a lesser degree in the Bockler paper. Yet, pushing the limits may lead to type I endoleaks that may be difficult to treat after EVAS. A novel technique introduces new complications and requires the building of experience with clinical and radiological follow up. AAA sack shrinkage is not to be expected after EVAS, and it has been noted that the appearance of type I endoleaks is different from that following conventional EVAR. 4,5 The definitive place of EVAS for AAA exclusion can only be defined after the robustness of the technique has been demonstrated after sufficient long term follow up.