Changes in suprarenal and infrarenal aortic angles after endovascular aneurysm repair

Abstract

PurposeWe investigated whether suprarenal and infrarenal aortic angles change after the endovascular aneurysm repair (EVAR) procedure and during follow-up, and investigated the correlation between infrarenal aortic angle after EVAR and type Ia endoleaks.MethodsData collected on 70 EVAR procedures for a fusiform infrarenal aortic aneurysm performed between May 2006 and December 2012 were supplemented with a retrospective review of charts and radiographs.ResultsThe greater the preoperative infrarenal aortic angle, the greater the suprarenal aortic angle (r = 0.72, P < 0.001). The infrarenal aortic angle decreased after the EVAR procedure and continued to decrease slowly thereafter (all P < 0.001). Suprarenal aortic angle decreased immediately after the EVAR procedure and continued to decrease during the first month (P < 0.001). No differences in angulation were observed based on stent graft type. Type Ia endoleaks occurred with significantly greater incidence in patients with a larger post EVAR infrarenal angle (P = 0.037).ConclusionThe infrarenal aortic angle decreased significantly immediately after the EVAR procedure and continued to decrease slowly thereafter. Suprarenal aortic angle decreased immediately after the EVAR procedure and continued to decrease during the first month. We found a correlation between infrarenal and suprarenal aortic angle. Type Ia endoleaks occurred with greater incidence in patients with a larger infrarenal angle immediately after EVAR.

Immediate Change in Suprarenal Neck Angulation After Endovascular Aneurysm Repair

“…The authors showed a statistically significant change in the mean suprarenal and infrarenal angles by a mean difference of 5°±1° and 8°±2°, respectively (p<0.01). Similarly, Lee et al 9 observed an immediate (1 month) decrease in the supra- and infrarenal angles after EVAR (32.1°±21.6° to 27.0°±17.8° and 43.4°±25.0° to 30.4°±17.6°, respectively). Interestingly, a recent bioengineering study by De Bock et al 10 demonstrated that the suprarenal angle can more adversely influence neck geometry as it was found to correlate with greater asymmetry in the forces distributed over the aortic neck, which is a relative measure of how these forces act to straighten the proximal neck.…”

“…Interestingly, Lee et al 9 reported a strong association between the preoperative suprarenal and infrarenal angulation in their study (r=0.72, p<0.001), which included stent-grafts with nitinol-based radial force involving a suprarenal fixation stent (Zenith, Endurant) or not (Excluder). According to their study, the suprarenal aortic angle decreased immediately after EVAR and continued to decrease during the first month, unlike the infrarenal aortic angle that continued to decrease slowly thereafter.…”

“…However, the role of post-EVAR infrarenal angulation change should not be underestimated, since it affects the flow recirculation and separation in the cephalad segment of the endograft, influences strongly the displacement forces acting on the endograft, and has been associated with the risk of migration and type Ia endoleak. 9,17–19…”

“…It has been shown that the neck angulation decreases immediately after EVAR and continues to decrease slowly thereafter. 8,9 van Keulen et al 8 investigated the alteration of aortic neck angulation immediately after EVAR using nitinol self-expanding endografts with either suprarenal (Talent; Medtronic CardioVascular, Santa Rosa, CA, USA) or infrarenal fixation (Excluder; W.L. Gore & Associates, Flagstaff, AZ, USA).…”

Changes in Neck Angle, Neck Length, Maximum Diameter, Maximum Area and Thrombus after Endovascular Aneurysm Repair

“…Many researchers reported the disadvantages and poor outcomes of EVAR in the treatment of aneurysms with hostile neck anatomy that did not meet the criteria [ 16 - 18 ]. The neck angle decreased significantly within 1 week after EVAR and then gradually decreased thereafter [ 6 , 7 , 19 ]. When the preoperative neck angle was greater than 60°, it decreased immediately after EVAR [ 19 ].…”