Transrenal Fixation of Aortic Stent-Grafts:Current Status and Future Directions

Abstract

Aortic stent-graft repair has been widely used in clinical practice for more than a decade, achieving satisfactory results compared to open surgical techniques. Transrenal fixation of stent-grafts is designed to obtain secure fixation of the proximal end of the stent-graft to avoid graft migration and to prevent type I endoleak. Unlike infrarenal deployment of stent-grafts, transrenal fixation takes advantage of the relative stability of the suprarenal aorta as a landing zone for the uncovered struts of the proximal stent. These transostial wires have sparked concern about the patency of the renal arteries, interference with renal blood flow, and effects on renal function. Although short to midterm results with suprarenal stent-grafts have not shown significant changes in renal function, long-term effects of this technique are still not fully understood. This review will explore the current status of transrenal fixation of aortic stent-grafts, potential risks of stent struts relative to the renal ostium, alternative methods to preserve blood flow to the renal arteries, and future directions or developments in stent-graft design to prevent myointimal proliferation around the stent struts.

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Commentary: Evidence for Contrast-Enhanced Ultrasound in Fenestrated EVAR Surveillance

“…23–29,46 Despite the advantages of CTA in the identification of stent-graft details, the deleterious effect on renal function, radiation exposure, and significant cost of this surveillance procedure are considered problematic. As the authors recommended, 4-view abdominal radiographs should always be performed at the same time as ultrasound, 47 and the findings of both examinations should be interpreted together. This reduces the amount of radiation to <1 mSv (typical plain radiograph), thus significantly minimizing the radiation-induced risk of malignancy.…”

Influence of Suprarenal Stentgraft Fixation on Renal Function in Patients After Abdominal Aortic Aneurysm Endovascular Exclusion

“…Fixation is achieved by a special wire scaffold, which is suspended across the orfices of the renal arteries (11,12,13). Some concern is given to the fact that the stent expanded across the orfices of the renal arteries may lead towards impaired blood flow to the kidneys resulting in renal infarcts or an increased creatinine level (14,15).…”

“…Experimental studies have proven that enhancing the endograft construction with extra hooks and barbs increases thrombocyte activation, thrombus formation and stimulates neointimal growth (14).…”