Endovascular stent graft repair of abdominal aortic aneurysms: Current status and future directions (original) (raw)
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Korean Journal of …, 2009
Fenestrated endovascular repair of an abdominal aortic aneurysm has been developed to treat patients with a short or complicated aneurysm neck. Fenestration involves creating an opening in the graft fabric to accommodate the orifice of the vessel that is targeted for preservation. Fixation of the fenestration to the renal arteries and the other visceral arteries can be done by implanting bare or covered stents across the graft-artery ostia interfaces so that a portion of the stent protrudes into the aortic lumen. Accurate alignment of the targeted vessels in a longitudinal aspect is hard to achieve during stent deployment because rotation of the stent graft may take place during delivery from the sheath. Understanding the 3D relationship of the aortic branches and the fenestrated vessel stents following fenestration will aid endovascular specialists to evaluate how the stent graft is situated within the aorta after placement of fenestrations. The aim of this article is to provide the 2D and 3D imaging appearances of the fenestrated endovascular grafts that were implanted in a group of patients with abdominal aortic aneurysms, based on the multislice CT angiography. The potential applications of each visualization technique were explored and compared with the 2D axial images.
ANZ Journal of Surgery, 2009
Background: This study aimed to investigate the diagnostic value of computed tomography virtual intravascular endoscopy (VIE) in the follow-up of patients with abdominal aortic aneurysm (AAA) treated with fenestrated stent grafts. Methods: A total of 19 patients (17 males and 2 females; mean age: 75 years) with AAA undergoing fenestrated stent grafts were retrospectively studied. Pre-and postfenestration computed tomography data were reconstructed for the generation of VIE images of aortic ostia and fenestrated stents and compared with two-dimensional axial and multiplanar reformation (MPR) images. Serum creatinine was measured pre and post fenestration to evaluate the renal function. Results: The mean intra-aortic length measured by VIE, two-dimensional axial and MPR were 4.7, 4.4 and 4.6 mm, respectively, for the right renal stent; 5.0, 4.9 and 5.0 mm, respectively, for the left renal stent; and 5.9, 6.0 and 6.0 mm, respectively, for the superior mesenteric artery stent. Comparisons of these measurements did not show significant difference (P > 0.05). The mean diameters of renal artery ostia measured on VIE visualization pre and post fenestration were 9.2 ¥ 8.3 and 10 ¥ 8.9 mm for the right renal ostium; 8.3 ¥ 7.1 and 9.9 ¥ 8.9 mm for the left renal ostium, with significant changes observed (P < 0.01). No renal dysfunction was observed in this group. Conclusion: VIE is a valuable visualization tool in the follow-up of fenestrated stent graft repair of AAA by providing intraluminal appearance of fenestrated stents and measuring the length of stent protrusion.
2009
Background: Endovascular repair is fast becoming the treatment of choice for abdominal aortic aneurysms in anatomically suitable patients. Precise sizing of the stent-graft ensures correct fixation of the stent and therefore helps to increase the lifespan of the device. 3D reconstructions also allow further analyses of the problem using additional software to indicate possible rupture sites and unnatural flow patterns. Methods: CT scan data for four male patients awaiting endovascular repair were obtained. Thresholding and segmentation of images is performed based on pixel intensities allowing 3D reconstruction. Wall stress was determined on one particular case using finite element analysis. Results: 3D reconstruction allows measurement to be obtained than can be difficult to measure using 2D images, thus complimenting traditional 2D measurements, allowing the correct sizing of stent-grafts for each patient. Reconstructions also provided imaging of potential anatomical problems, for example, extreme tortuosity of the proximal neck and access vessel calcification. Wall stress results showed key regions that may be possible rupture sites. Conclusion: 3D reconstructions greatly aid surgical planning. As stent-graft devices evolve, anatomical difficulties previously considered contraindications to endovascular repair can now be overcome with careful planning. 3D reconstruction is a useful adjunct to assessment and planning of endovascular repair.
A critical appraisal of endovascular stent-grafts in the management of abdominal aortic aneurysms
La Radiologia medica, 2017
Endovascular repair of abdominal aortic aneurysms has widely replaced the open surgical repair due to its minimal invasive nature and the accompanying lower perioperative mortality and morbidity. During the past two decades, certain improvements and developments have provided a wide variety of endograft structural designs and geometric patterns, enabling the physician to approach a more patient-specific treatment of AAA. This review presents the currently available aortic endografts and describes the clinical, technical and mechanical characteristics of them.
Clinical Imaging, 2010
An aortic stent graft is frequently used to cure an abdominal aortic aneurysm (AAA). It is critical to accurately fit the size and shape of the stent graft to the target region on the aorta. Proper sizing and shaping require the measurement of the orthogonal diameter of the target region from medical images. The present study aimed to acquire an accurate three-dimensional (3D) reconstruction of the aorta to determine the shape of the cross-sectional area where the stent graft would be implanted. A conventional geometric-active contour model was enhanced to prevent blurring and to improve edge detection with high noise resistivity. After the segmentation of two-dimensional (2D) images using the model, a 3D-reconstructed configuration of the aorta was achieved using a surface-rendering technique. The model could segment several selected synthetic images more accurately than conventional methods. Also, a 3D-reconstructed configuration of the abdominal aorta could be achieved using boundary coordinates extracted from 2D image segmentation. This preliminary study indicates the utility of the approach in optimizing stent graft configuration for AAA patients, thus enhancing stent graft healing.
The Journal of cardiovascular surgery, 2012
The Endurant stent-graft (Medtronic, Inc., Minneapolis, MN, USA) is a latest generation device for the treatment of abdominal aortic aneurysm. The idea behind designing such a graft came from the intention to broad the instruction for use (IFU) and to enable it to treat more challenging anatomy including the 10mm neck lengths, and more severe suprarenal and infrarenal angulations. Endurant stent-graft has active fixation through suprarenal stent with anchoring pins to provide migration resistance, optimized heights of stents and spacing between them for improved flexibility and conformability, low-profile delivery system with hydrophilic coating and controlled simple deployment mechanism. Short term results are excellent. Technical and clinical success is confirmed in Regulatory trials (EU and USA), as well as in ENGAGE and the Canadian registry. Many current publications record the use of Endurant stent-graft outside the Instruction for use. The results in a group of patients outsi...
Endovascular Stent Graft Repair of Abdominal and Thoracic Aortic Aneurysms
Annals of Surgery, 2003
Objective:On November 23, 1992, the first endovascular stent graft (ESG) repair of an aortic aneurysm was performed in North America. Following the treatment of this patient, we have continued to evaluate ESG over the past 10 years in the treatment of 817 patients.Summary and Background Data:Abdominal (AAA) or thoracic (TAA) aortic aneurysms are a significant health concern traditionally treated by open surgical repair. ESG therapy may offer protection from aneurysm rupture with a reduction in procedure morbidity and mortality.Methods:Over a 10-year period, 817 patients were treated with ESGs for AAA (723) or TAA (94). Patients received 1 of 12 different stent graft devices. Technical and clinical success of ESGs was reviewed, and the incidence of procedure-related complications was analyzed.Results:The mean age was 74.3 years (range, 25–95 years); 678 patients (83%) were men; 86% had 2 or more comorbid medical illnesses, 67% of which included coronary artery disease. Technical success, on an intent-to-treat basis was achieved in 93.8% of patients. Primary clinical success, which included freedom from aneurysm-related death, type I or III endoleak, graft infection or thrombosis, rupture, or conversion to open repair was 65 ± 6% at 8 years. Of great importance, freedom from aneurysm rupture after ESG insertion was 98 ± 1% at 9 years. There was a 2.3% incidence of perioperative mortality. One hundred seventy five patients died of causes not related to their aneurysm during a mean follow-up of 15.4 months.Conclusions:Stent graft therapy for aortic aneurysms is a valuable alternative to open aortic repair, especially in older sicker patients with large aneurysms. Continued device improvements coupled with an enhanced understanding of the important role of aortic pathology in determining therapeutic success will eventually permit ESGs to be a more durable treatment of aortic aneurysms.
Acta chirurgica Belgica, 2003
Endovascular grafting of abdominal aortic aneurysms should be offered only to those patients with suitable anatomy. This is especially true at the level of the proximal aortic neck in order to secure long-term proximal fixation. Aortoiliac anatomy is easy to understand conceptually, however, it is difficult to define and measure quantitatively. In this article, we discuss the use of three dimensional computed tomographic angiography to determine aneurysm morphology and select patients for endovascular repair. Specifically, we apply our methods to define and measure angulation of the aorta and iliac arteries. The anatomic definition of the angulation of the proximal aortic neck is emphasized.
PURPOSE/AIM The purpose of the study was to explore the application of 3D stereoscopic visualization in the evaluation of patients with abdominal aortic aneurysm treated with fenestrated endovascular grafts. CONTENT ORGANIZATION A. Types of aortic aneurysms and aortic stent grafts B. Fenestrated stent grafting and its types of treatment C. Diagnostic imaging for follow-up of fenestrated stent grafts (CT) D. Conventional 2D and 3D CT imaging reconstructions E. Generation of 3D stereoscopic visualization F. 3D stereoscopic visualization in comparison to 2D/3D CT visualizations for assessment of fenestrated stent graft repair of abdominal aortic aneurysms SUMMARY 3D stereoscopic visualization enhances the endovascular specialists’ ability to accurately evaluate the treatment outcomes of fenestrated repair of abdominal aortic aneurysms. This exhibits reviews: a. Fenestrated stent graft repair of aortic aneurysms; b. Potential value of 3D stereoscopic views for the assessment of fenestra...