Analysis of the position of EndoAnchor implants in therapeutic use during endovascular aneurysm repair

Objective: The aim of this study was to analyze the penetration depth, angles, distribution, and location of deployment of individual EndoAnchor (Medtronic Vascular, Santa Rosa, Calif) implants.Methods: Eighty-six primary and revision arm patients (procedural success, 53; persistent type IA endoleak, 33) treated for type IA endoleaks with a total of 580 EndoAnchor implants from a subset of the Aneurysm Treatment Using the Heli-FX Aortic Securement System Global Registry (ANCHOR) were included in this study. Procedural success was defined as the absence of a type IA endoleak on the first postprocedural computed tomography scan after the EndoAnchor implantation procedure. Endograft malapposition along the circumference was assessed at the first postoperative computed tomography scans and expressed as clock-face range and width in degrees and normalized such that the center was translated to 0 degrees. The position and penetration of each EndoAnchor implant were measured as the clock-face orientation. EndoAnchor implant penetration into the aortic wall was categorized as follows: good penetration, >= 2 mm; borderline penetration, = 2-mm gap between the endograft and aortic wall; or no penetration. The orthogonal and longitudinal angles between the EndoAnchor implant and the interface plane of the aortic wall were determined. Location of deployment was investigated for each EndoAnchor implant and classified as maldeployed when it was above the fabric or in a gap >2mm between the endograft and aortic wall due to >2-mm thrombus or positioning of the EndoAnchor implant below the aortic neck.Results: A total of 170 (29%) EndoAnchor implants had maldeployment and were therefore beyond recommended use and not useful. After EndoAnchor implantation, the procedural success and persistent type IA endoleak groups had 3 (1%) and 4 (2%) EndoAnchor implants positioned above the fabric as well as 60 (18%) and 103 (42%) placed in a gap >2 mm, respectively. The amount of EndoAnchor implants with good, borderline, and no penetration was significantly different between both groups (success vs type IA endoleak) after exclusion of maldeployed EndoAnchor implants (235 [87.4%], 14 [5.2%], and 20 [7.4%] vs 97 [68.8%], 18 [12.8%], and 26 [18.4%], respectively; P <.001). Good penetration EndoAnchor implants were more closely aligned with a 90-degree orthogonal angle than the borderline penetration and non-penetrating EndoAnchor implants. The longitudinal angle was more distributed, which was observed through all three penetration groups.Conclusions: In this subcohort of ANCHOR patients, almost 30% of the EndoAnchor implants had maldeployment, which may be prevented by careful preoperative planning and measured intraoperative deployment. If endoleaks are due to >2-mm gaps, EndoAnchor implants alone may not provide the intended sealing, and additional devices should be considered.