Sustainability of Individual EndoAnchor Implants in Therapeutic Use to Treat Type Ia Endoleak After Endovascular Aneurysm Repair

Purpose: To investigate changes in penetration depths and angles of EndoAnchor implants with initially good penetration after therapeutic use in endovascular aneurysm repair. Materials and Methods: Patients were selected from the Aneurysm Treatment Using the Heli-FX Aortic Securement System Global Registry (ANCHOR; ClinicalTrials.gov identifier NCT01534819). Inclusion criteria were (1) EndoAnchor implantation to treat intraoperative or late type Ia endoleak and (2) at least 2 postoperative computed tomography angiography (CTA) scans. Exclusion criteria were the use of adjunct procedures. Based on these criteria, 54 patients (44 men) with 360 EndoAnchor implants were eligible for this analysis. Penetration depth of each EndoAnchor implant into the aortic wall was judged as (1) good (2-mm penetration), (2) borderline (</p

Effect of Different EndoAnchor Configurations on Aortic Endograft Displacement Resistance: An Experimental Study

Purpose: This study investigated the effect of different EndoAnchor configurations on aortic endograft displacement resistance in an in vitro model. Materials and Methods: An in vitro model was developed and validated to perform displacement force measurements on different EndoAnchor configurations within an endograft and silicone tube. Five EndoAnchor configurations were created: (1) 6 circumferentially deployed EndoAnchors, (2) 5 EndoAnchors within 120° of the circumference and 1 additional, contralateral EndoAnchor, (3) 4 circumferentially deployed EndoAnchors, (4) 2 rows of 4 circumferentially deployed EndoAnchors, and (5) a configuration of 2 columns of 3 EndoAnchors. An experienced vascular surgeon deployed EndoAnchors under C-arm guidance at the proximal sealing zone of the endograft. A constant force with increments of 1 newton (N) was applied to the distal end of the endograft. The force necessary to displace a part of the endograft by 3 mm was defined as the endograft displacement force (EDF). Two video cameras recorded the measurements. Videos were examined to determine the exact moment 3-mm migration had occurred at part of the endograft. Five measurements were performed after each deployed EndoAnchor for each configuration. Measurements are given as the median and interquartile range (IQR) Q1, Q3. Results: Baseline displacement force measurement of the endograft without EndoAnchors resulted in a median EDF of 5.1 N (IQR 4.8, 5.2). The circumferential distribution of 6 EndoAnchors resulted in a median EDF of 53.7 N (IQR 49.0, 59.0), whereas configurations 2 through 5 demonstrated substantially lower EDFs of 29.0 N (IQR 28.5, 30.1), 24.6 N (IQR 21.9, 27.2), 36.7 N, and 9.6 N (IQR 9.4, 10.0), respectively. Decreasing the distance between the EndoAnchors over the circumference of the endograft increased the displacement resistance. Conclusion: This in vitro study demonstrates the influence EndoAnchor configurations have on the displacement resistance of an aortic endograft. Parts of the endograft where no EndoAnchor has been deployed remain sensitive to migration. In the current model, the only configuration that rivaled a hand-sewn anastomosis was the one with 6 EndoAnchors. A circumferential distribution of EndoAnchors with small distances between EndoAnchors should be pursued, if possible. This study provides a quantification of different EndoAnchor configurations that clinicians may have to adopt in clinical practice, which can help them make a measured decision on where to deploy EndoAnchors to ensure good endograft fixation

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 2-mm gaps, EndoAnchor implants alone may not provide the intended sealing, and additional devices should be considered