In Vitro Quantification of Gutter Formation and Chimney Graft Compression in Chimney EVAR Stent-Graft Configurations Using Electrocardiography-Gated Computed Tomography

2018 ◽  
Vol 25 (3) ◽  
pp. 387-394 ◽  
Author(s):  
Simon P. Overeem ◽  
Esmé J. Donselaar ◽  
Jorrit T. Boersen ◽  
Erik Groot Jebbink ◽  
Cornelis H. Slump ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Stent Graft ◽  
Cardiac Cycle ◽  
Intraclass Correlation ◽  
Endovascular Aneurysm Repair ◽  
Enhanced Computed Tomography ◽  
Geometric Changes ◽  
Aneurysm Repair ◽  
Chimney Graft

Purpose: To assess the dynamic behavior of chimney grafts during the cardiac cycle. Methods: Three chimney endovascular aneurysm repair (EVAR) stent-graft configurations (Endurant and Advanta V12, Endurant and Viabahn, and Endurant and BeGraft) were placed in silicone aneurysm models and subjected to physiologic flow. Electrocardiography (ECG)-gated contrast-enhanced computed tomography was used to visualize geometric changes during the cardiac cycle. Endograft and chimney graft surface, gutter volume, chimney graft angulation over the center lumen line, and the D-ratio (the ratio between the lengths of the major and minor axes) were independently assessed by 2 observers at 10 time points in the cardiac cycle. Results: Both gutter volumes and chimney graft geometry changed significantly during the cardiac cycle in all 3 configurations (p<0.001). Gutters and endoleaks were observed in all configurations. The largest gutter volume (232.8 mm3) and change in volume (20.7 mm3) between systole and diastole were observed in the Endurant-Advanta configuration. These values were 2.7- and 3.0-fold higher, respectively, compared to the Endurant-Viabahn configuration and 1.7- and 1.6-fold higher as observed in the Endurant-BeGraft configuration. The Endurant-Viabahn configuration had the highest D-ratio (right, 1.26–1.35; left, 1.33–1.48), while the Endurant-BeGraft configuration had the lowest (right, 1.11–1.17; left, 1.08–1.15). Assessment of the interobserver variability showed a high correlation (intraclass correlation >0.935) between measurements. Conclusion: Gutter volumes and stent compression are dynamic phenomena that reshape during the cardiac cycle. Compelling differences were observed during the cardiac cycle in all configurations, with the self-expanding (Endurant–Viabahn) chimney EVAR configurations having smaller gutters and less variation in gutter volume during the cardiac cycle yet more stent compression without affecting the chimney graft surface.

Validation of a New Methodology to Determine 3-Dimensional Endograft Apposition, Position, and Expansion in the Aortic Neck After Endovascular Aneurysm Repair

2018 ◽  
Vol 25 (3) ◽  
pp. 358-365 ◽  
Author(s):  
Richte C. L. Schuurmann ◽  
Simon P. Overeem ◽  
Kim van Noort ◽  
Bastiaan A. de Vries ◽  
Cornelis H. Slump ◽  
...  
Keyword(s):  
Intraclass Correlation ◽  
Endovascular Aneurysm Repair ◽  
Slice Thickness ◽  
3 Dimensional ◽  
Aortic Neck ◽  
Radial Forces ◽  
Aneurysm Repair ◽  
Neck Diameter

Purpose: To validate a novel methodology employing regular postoperative computed tomography angiography (CTA) scans to assess essential factors contributing to durable endovascular aneurysm repair (EVAR), including endograft deployment accuracy, neck adaptation to radial forces, and effective apposition of the fabric within the aortic neck. Methods: Semiautomatic calculation of the apposition surface between the endograft and the infrarenal aortic neck was validated in vitro by comparing the calculated surfaces over a cylindrical silicon model with known dimensions on CTA reconstructions with various slice thicknesses. Interobserver variabilities were assessed for calculating endograft position, apposition, and expansion in a retrospective series of 24 elective EVAR patients using the repeatability coefficient (RC) and the intraclass correlation coefficient (ICC). The variability of these calculations was compared with variability of neck length and diameter measurements on centerline reconstructions of the preoperative and first postoperative CTA scans. Results: In vitro validation showed accurate calculation of apposition, with deviation of 2.8% from the true surface for scans with 1-mm slice thickness. Excellent agreement was achieved for calculation of the endograft dimensions (ICC 0.909 to 0.996). Variability was low for calculation of endograft diameter (RC 2.3 mm), fabric distances (RC 5.2 to 5.7 mm), and shortest apposition length (RC 4.1 mm), which was the same as variability of regular neck diameter (RC 0.9 to 1.1 mm) and length (RC 4.0 to 8.0 mm) measurements. Conclusion: This retrospective validation study showed that apposition surfaces between an endograft and the infrarenal neck can be calculated accurately and with low variability. Determination of the (ap)position of the endograft in the aortic neck and detection of subtle changes during follow-up are crucial to determining eventual failure after EVAR.

Changes in Apposition of Endograft Limbs in the Iliac Arteries After Endovascular Aneurysm Repair: Determination With New Computed Tomography–Applied Software

2019 ◽  
Vol 26 (6) ◽  
pp. 843-852 ◽  
Author(s):  
Seline R. Goudeketting ◽  
Richte C. L. Schuurmann ◽  
Cornelis H. Slump ◽  
Jean-Paul P. M. de Vries
Keyword(s):  
Computed Tomography ◽  
Ct Scan ◽  
Interobserver Agreement ◽  
Intraclass Correlation ◽  
Endovascular Aneurysm Repair ◽  
Accurate Analysis ◽  
Applied Software ◽  
Aneurysm Repair ◽  
And Control

Purpose: To validate new computed tomography (CT)–applied software used to determine endograft limb position and apposition after endovascular aneurysm repair (EVAR). Materials and Methods: Twelve EVAR patients (mean age 81±6 years; 10 men) with distal stent-graft extensions for 15 (3 bilateral) type Ib endoleaks during follow-up were selected based on the availability of the following CT studies: pre-EVAR, 1 month, and the penultimate scan prior to the scan disclosing the type Ib endoleak. Twelve patients (mean age 82±7 years; 11 men) without endoleak and a similar interval between the primary EVAR procedure and the penultimate CT scan of the endoleak group were selected as controls using measurements from both endograft limbs (n=21, 3 excluded). Prototype Vascular Imaging Analysis software was adapted to calculate 6 parameters for the distal apposition zone: fabric distance, shortest apposition length, endograft diameter, iliac seal surface (ISS), iliac endograft apposition surface (IEAS), and percentage of iliac surface coverage (IEAS/ISS × 100). Measurements were performed on the preoperative, first postoperative, and penultimate/matched follow-up CT scans. Interobserver variability was assessed with the intraclass correlation coefficient (ICC). Continuous data are presented as the median [interquartile range (IQR) Q1, Q3]. Results: CTA follow-up was not significantly different between the endoleak and control groups [30 months (IQR 18, 58) vs 36 months (IQR 21, 59), p=0.843]. Interobserver agreement was good to excellent for all parameters (ICC 0.879–0.985). Preoperative anatomy and endograft dimensions on the first follow-up CTA scan did not differ significantly between the groups. When the penultimate CTA scan was compared with the first postoperative CT scan, endograft dimensions had significantly changed in the endoleak group; importantly, apposition was significantly decreased, and fabric distance was significantly increased, indicating limb retraction. Differences in changes in endograft dimensions were significant between the groups. Conclusion: New CT-applied software was introduced to visualize apposition and position changes of endograft limbs during follow-up. The software demonstrated good-to-excellent interobserver agreement and enabled accurate analysis of post-EVAR endograft dimensions. Significant changes in apposition and position were observed with the software on the penultimate CT scan prior to diagnosis of type Ib endoleak.

Endoleaks: current concepts and treatments

2021 ◽  
Author(s):  
Zia Ur Rehman
Keyword(s):  
Stent Graft ◽  
Treatment Options ◽  
Endovascular Aneurysm Repair ◽  
Aneurysm Rupture ◽  
Special Situation ◽  
Type V ◽  
Aneurysm Repair ◽  
Benign Course ◽  
Selection Of

Endoleaks are the most common complications following endovascular aneurysm repair. Depending upon their origin, there are five types of endoleaks, types I-V, which can also be classified as direct and indirect endoleaks. Direct endoleaks type 1 and III have higher risk of aneurysm rupture due to rapid sac expansion, and require immediate correction.  Indirect endoleaks types II, IV and V have a relatively benign course compared to direct endoleaks. Most of them resolve with time and very few of them need interventions upon sac enlargement. Type V endotension is a special situation where there is sac enlargement despite no demonstrable endoleak. Proper planning and appropriate selection of stent-graft can prevent most of these endoleaks. With improvement in stent-graft technology, the incidence of endoleaks has been reduced. The current narrative review was planned to describe the pathophysiology, risk factors and treatment options for each type of endoleak. Continuous...

scholarly journals Endovascular Aneurysm Sealing of a Collapsed and Thrombosed Aortic Stent-Graft With Renovisceral Chimney Stent-Grafts

2018 ◽  
Vol 26 (1) ◽  
pp. 72-75
Author(s):  
Fabien Lareyre ◽  
Claude Mialhe ◽  
Carine Dommerc ◽  
Juliette Raffort
Keyword(s):  
Stent Graft ◽  
Mesenteric Artery ◽  
Endovascular Aneurysm Repair ◽  
Stent Grafts ◽  
Aortic Thrombosis ◽  
Aortic Stent Graft ◽  
Aneurysm Repair ◽  
Stent Graft Implantation ◽  
Graft Implantation

Purpose: To report the use of the Nellix endovascular aneurysm sealing (EVAS) system in the management of proximal stent-graft collapse associated with thrombosis following endovascular aneurysm repair (EVAR). Case Report: A 76-year-old man was admitted for proximal collapse of an aortic extension following bifurcated AFX stent-graft implantation associated with chimney grafts in both renal arteries and the superior mesenteric artery 1 month prior. Imaging identified thrombosis of the aortic stent-graft and the iliac limbs. A Nellix EVAS was placed into the AFX stent-graft to recanalize the aneurysm lumen and address the aortic thrombosis. There was no endoleak, and the renovisceral chimney stent-grafts remained patent over a follow-up of 25 months. Conclusion: While further studies are required to generalize its use, EVAS appears to be feasible in the management of aortic stent-graft collapse.

Sign in / Sign up

Export Citation Format

Share Document