How ChEVAR changed our approach in hostile AAA necks

Cornelis JJM Sikkink and Lee H Bouwman detail how chimney endovascular aneurysm repair (ChEVAR) has changed their approach in hostile abdominal aortic aneurysm (AAA) neck management, summarising that a standardised approach has been a key factor to ensure procedural success.

CHEVAR HAS BEEN PRESENT IN

endovascular specialists’ armamentarium for many years, but has always been relegated to a bailout option due to lack of a standardised approach reflected in contradicting published evidence. Further resistance to the technique was due to concerns regarding gutters and intraoperative endoleaks.

The PERICLES study helped to clarify multiple aspects, such as the spontaneous resolution of gutter endoleaks when oversizing and new sealing zone requirements are correctly applied. Additionally, multiple benchmodel studies have reported Endurant (Medtronic) and Advanta V12 (Getinge) to morphologically adapt well to each other, reducing gutter areas and minimising stent compression.1–3

Further contribution to a standardised approach was achieved in 2016, when Medtronic received CE mark for the Endurant II/IIs stent graft system to treat patients with AAA using ChEVAR, based on the clinical findings of the PROTAGORAS trial.4 The ongoing ENCHANT multicentre prospective trial is set to add further robust evidence that might support future therapy guidelines.

At our hospital, we are participating in the ENCHANT trial and have enrolled several patients over the last three years. Early results of these patients are promising but more long-term outcomes are desired.

To be noted, 2019 AAA treatment guidelines from the European Society for Vascular Surgery now recommend ChEVAR in urgent cases and when fenestrated repair is unfeasible or contraindicated.

In our institution, we started to adopt ChEVAR because we were regularly confronted with patients with short Cornelis JJM Sikkink and hostile necks, who were not ideal candidates for open surgical repair. We wanted an easy off-theshelf alternative in cases with inadequate infrarenal sealing zones where EVAR was not feasible and fenestrated EVAR (FEVAR) was excluded due to anatomical or logistical factors, for instance in semi-emergency cases. Although not determinative, economic factors are also evident. The main advantages we see, compared to custom-made solutions, are the immediate availability, fewer access problems due to the smaller profile, and the

We feel that this technique is of particular value in the patients with infrarenal aortic necks between 3–8mm in length.”

possibility of gaining a long suprarenal sealing zone with a relatively easy approach compared to use of a fourfenestrated stent graft. We feel that this technique is Lee H Bouwman of particular value in patients with infrarenal aortic necks between 3–8mm in length.

In conclusion, in our experience the chimney technique remains an effective complementary alternative modality in inadequate infrarenal sealing zones and a standardised approach has been a key factor to ensure ChEVAR success.

References

1. Donas KP, Usai MV, Taneva GT, et al. Impact of aortic stentgraft oversizing on outcomes of the chimney endovascular technique based on a new analysis of the PERICLES registry.

Vascular 2019; 27: 175–180. 2. Donas KP, Lee JT, Lacaht M, et al. Collected world experience about the performance of the snorkel/chimney endovascular technique in the treatment of complex aortic pathologies: the PERICLES registry. Ann Surg 2015; 262: 546–553. 3. Mestres G, Uribe JP, Garcia-Madrid C, et al. The best conditions for parallel stenting during EVAR: an in vitro study.

Eur J Vasc Endovasc Surg 2012; 44: 468–473. 4. Donas KP, Torsello GB, Piccoli G, et al. The PROTAGORAS study to evaluate the performance of the Endurant stent graft for patients with pararenal pathologic processes treated by the chimney/snorkel endovascular technique. J Vasc Surg 2016; 63: 1–7.

Cornelis JJM Sikkink and Lee H Bouwman are vascular surgeons at the Zuyderland Medical Center in Heerlen, The Netherlands.

Figure 1. CT angiogram of a patient with a hostile neck 7mm long. Figure 2. Final intraoperative angiogram, with patent renal stents and the stent graft just below the SMA. Figure 3. 3D reconstruction, four weeks after the procedure; patent vessels/stents, no endoleak.