scholarly journals A Comparative Study on the Hemodynamic Performance Within Cross and Non-cross Stent-Grafts for Abdominal Aortic Aneurysms With an Angulated Neck

2021 ◽  
Vol 12 ◽  
Author(s):  
Ming Qing ◽  
Yue Qiu ◽  
Jiarong Wang ◽  
Tinghui Zheng ◽  
Ding Yuan

Objectives: Cross-limb stent grafts for endovascular aneurysm repair (EVAR) are often employed for abdominal aortic aneurysms (AAAs) with significant aortic neck angulation. Neck angulation may be coronal or sagittal; however, previous hemodynamic studies of cross-limb EVAR stent grafts (SGs) primarily utilized simplified planar neck geometries. This study examined the differences in flow patterns and hemodynamic parameters between crossed and non-crossed limb SGs at different spatial neck angulations.Methods: Ideal models consisting of 13 cross and 13 non-cross limbs were established, with coronal and sagittal angles ranging from 0 to 90°. Computational fluid dynamics (CFD) was used to capture the hemodynamic information, and the differences were compared.Results: With regards to the pressure drop index, the maximum difference caused by the configuration and angular direction was 4.6 and 8.0%, respectively, but the difference resulting from the change in aneurysm neck angle can reach 27.1%. With regards to the SAR-TAWSS index, the maximum difference caused by the configuration and angular direction was 7.8 and 9.8%, respectively, but the difference resulting from the change in aneurysm neck angle can reach 26.7%. In addition, when the aneurysm neck angle is lower than 45°, the configuration and angular direction significantly influence the OSI and helical flow intensity index. However, when the aneurysm neck angle is greater than 45°, the hemodynamic differences of each model at the same aneurysm neck angle are reduced.Conclusion: The main factor affecting the hemodynamic index was the angle of the aneurysm neck, while the configuration and angular direction had little effect on the hemodynamics. Furthermore, when the aneurysm neck was greatly angulated, the cross-limb technique did not increase the risk of thrombosis.

2019 ◽  
Vol 46 (3) ◽  
pp. 183-188 ◽  
Author(s):  
Edgar Luis Galiñanes ◽  
Eduardo A. Hernandez-Vila ◽  
Zvonimir Krajcer

Juxtarenal abdominal aortic aneurysms (AAAs) are difficult to treat because they often have little or no proximal aortic neck. Patients with this complex anatomy are not usually candidates for an endovascular aneurysm repair (EVAR). Chimney-graft EVAR has been introduced, but type Ia endoleak is a typical risk. We have begun using EndoAnchors to determine whether this risk can be reduced. From July 2013 through July 2014, we used the chimney-graft EVAR technique in 5 patients whose juxtarenal AAAs had a short or no proximal aortic neck. During the procedure, we implanted EndoAnchors as needed. Postprocedurally, at 30 days, and through end of follow-up (duration, 11–18 mo), all patients had patent endografts without type Ia endoleak (our primary endpoint), visceral stent-graft thrombosis, or renal complications. One patient who received 4 chimney grafts had a postprocedural type II endoleak, which was treated with embolization. We found it feasible to use EndoAnchors with the chimney-graft technique to prevent type Ia endoleaks in the treatment of juxtarenal AAAs. Further studies are needed to validate this adjunctive technique and to determine its durability.


2003 ◽  
Vol 10 (3) ◽  
pp. 453-457 ◽  
Author(s):  
Daniel F.G. Rose ◽  
Ian R. Davidson ◽  
Robert J. Hinchliffe ◽  
Simon C. Whitaker ◽  
Roger H. Gregson ◽  
...  

Purpose: To assess the anatomical suitability of ruptured abdominal aortic aneurysms (AAA) for emergency endovascular repair. Methods: All cases (46 patients [35 men; mean age 74 years, range 54–85]) in which computed tomographic angiography (CTA) confirmed AAA rupture over a 5-year period at our university hospital were reviewed for anatomical suitability for endovascular repair. Measurements were made by a radiologist experienced in anatomical assessment of CT criteria for elective endovascular aneurysm repair (EVAR). Results: The mean aneurysm neck length was 18 mm (range 0–59); 17 were conical, 13 straight, 4 barrel, and 6 reverse conical. Six cases had no proximal neck. Overall, 37 (80%) patients were unsuitable for EVAR according to our criteria. Nearly half the patients (22, 48%) had ≥2 adverse features. Unsuitable neck morphology (35, 76%) was the primary reason for exclusion, but CIA aneurysm (10, 22%) and EIA tortuosity (7, 15%) were secondary adverse features. Conclusions: With current stent-graft design, the majority of ruptured abdominal aortic aneurysms are anatomically unsuitable for endovascular repair.


Vascular ◽  
2017 ◽  
Vol 26 (3) ◽  
pp. 278-284 ◽  
Author(s):  
VP Bastiaenen ◽  
MGJ Snoeijs ◽  
JGAM Blomjous ◽  
J Bosma ◽  
VJ Leijdekkers ◽  
...  

Objectives Stent grafts for endovascular repair of infrarenal aneurysms are commercially available for aortic necks up to 32 mm in diameter. The aim of this study was to evaluate the feasibility of endovascular repair with large thoracic stent grafts in the infrarenal position to obtain adequate proximal seal in wider necks. Methods All patients who underwent endovascular aneurysm repair using thoracic stent grafts with diameters greater than 36 mm between 2012 and 2016 were included. Follow-up consisted of CT angiography after six weeks and annual duplex thereafter. Results Eleven patients with wide infrarenal aortic necks received endovascular repair with thoracic stent grafts. The median diameter of the aneurysms was 60 mm (range 52–78 mm) and the median aortic neck diameter was 37 mm (range 28–43 mm). Thoracic stent grafts were oversized by a median of 14% (range 2–43%). On completion angiography, one type I and two type II endoleaks were observed but did not require reintervention. One patient experienced graft migration with aneurysm sac expansion and needed conversion to open repair. Median follow-up time was 14 months (range 2–53 months), during which three patients died, including one aneurysm-related death. Conclusions Endovascular repair using thoracic stent grafts for patients with wide aortic necks is feasible. In these patients, the technique may be a reasonable alternative to complex endovascular repair with fenestrated, branched, or chimney grafts. However, more experience and longer follow-up are required to determine its position within the endovascular armamentarium.


Vascular ◽  
2005 ◽  
Vol 13 (6) ◽  
pp. 321-326 ◽  
Author(s):  
Jean-Noël Albertini ◽  
Maria-Angela DeMasi ◽  
Jan Macierewicz ◽  
Redouane El Idrissi ◽  
Brian R. Hopkinson ◽  
...  

Neck angulation (NA) is an important risk factor for type 1 proximal endoleaks following stenting of abdominal aortic aneurysms. The Aorfix (Lombard Medical, Oxon, UK) is a new flexible stent graft designed to overcome this issue. The aim of this study was to compare the endoleak flow rate (EFR) in relation to NA between the Aorfix and other manufactured stent grafts. A flow model with silicone proximal and distal necks was used. EFRs corresponding to 10 neck angles between 0 and 70° were measured. Eight stent grafts were tested: Aorfix, Ancure (Guidant, Indianapolis, IN), Powerlink (Endologix, Irvine, CA), AneuRx (Medtronic, Sunnyvale, CA), Excluder (W.L. Gore & Associates, Flagstaff, AZ), Zenith and Zenith-Flex (Cook Inc., Bloomington, IN), and Lifepath (Edwards Lifesciences, Irvine, CA). For all stent grafts except the Aorfix, the EFR was greater than at baseline for NA ≥ 30° ( p < .01). The EFR at NA ≥ 30° was lower with the Aorfix compared with the other stent grafts ( p < .01). NA had no influence on the EFR with the Aorfix. The Aorfix may decrease the incidence of proximal type 1 endoleak in patients with a severely angulated aortic neck.


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