Commentary: Are EndoAnchors up to the Challenge of a Hostile Proximal Neck?

Long-term data after endovascular aneurysm repair (EVAR) for infrarenal abdominal aortic aneurysms (AAAs) show similar results compared with open surgical treatment with a higher rate of reinterventions after EVAR. Therefore, EVAR patients require lifelong follow-up using ultrasound, radiography, and computed tomographic angiography (CTA) imaging to detect endoleaks, stent-graft nonalignment, migration, or fractures. These EVAR failures, and especially type Ia endoleaks and migration, are frequently attributed to insufficient sealing/fixation at the level of the infrarenal neck. In addition, a relevant number of EVAR reinterventions are attributed to a broader use of EVAR even in short, conical, or partially thrombosed infrarenal aortic necks outside the instructions for use. Therefore, infrarenal stent-graft fixation comparable to the anastomotic suture of an open surgical repair might improve the results of EVAR for infrarenal AAAs. One means of accomplishing this is through the use of EndoAnchors to prevent or repair proximal type Ia endoleak or migration. In the article by Jordan et al in this issue of the JEVT, the authors report their data from a subgroup analysis of patients in the ANCHOR prospective multicenter registry investigating prophylactic infrarenal EndoAnchor implantation for challenging aortic neck anatomy. The 208 patients analyzed were treated over a 28-month period at 43 centers. Type Ia endoleaks were identified in 1.5%, and the aneurysm diameter decreased by >5 mm in 43% after >1-year follow-up. Aneurysm-related reinterventions were performed in 8% of the patients. The authors concluded that EndoAnchor stent-graft fixation in patients with short hostile infrarenal necks is a valuable endovascular option. An important contribution of the ANCHOR registry is the definition of a hostile neck. Patients were enrolled in the registry based on the vascular interventionist’s subjective estimate of the risk of type Ia endoleak, migration, or stentgraft nonalignment according to per-institution hostile neck criteria. Retrospective reevaluation of infrarenal neck anatomy and indication for EndoAnchor fixation was performed by the core laboratory using the following criteria: neck length <10 mm, diameter >28 mm, angulation >60°, mural thrombus or calcium >2 mm in thickness or >180° in circumference, or a conical shape on assessable preoperative CTA scans from 157 patients. Approximately 20% (34/157) did not meet the anatomical thresholds for a hostile neck as assessed by the core laboratory. Therefore, while inclusion into the registry reflected the use of EndoAnchors in daily practice at each center, these results from the core laboratory suggest that the criteria used in the analysis might become a general recommendation for defining a hostile neck. Another matter of concern is that almost 25% of the patients (51/208) included in the study had preoperative CTA images that made it difficult for the core laboratory to identify the criteria for hostile neck anatomy and, most likely, also for the team performing the stent-graft implantation with EndoAnchor fixation. Therefore, to evaluate the best treatment for infrarenal AAAs with short or challenging necks, high resolution CTA with thin slices, usually ≤1 mm, are required, with a clear institutional definition for infrarenal hostile neck anatomy to consider infrarenal stent-graft implantation either with or without EndoAnchor fixation. EndoAnchor fixation was used in some centers even in patients with very short infrarenal aortic necks; almost 14% of the patients had neck lengths <5 mm, which is outside any instructions for use for infrarenal stent-grafts. In our opinion, this group of patients with very short infrarenal 574686 JETXXX10.1177/1526602815574686Journal of Endovascular TherapyKopp and Kasprzak research-article2015