Routine use of an aortic balloon to resolve possible inflow stenosis induced by the inflatable ring fixation mechanism of the Ovation endograft.

Abstract

To investigate if the routine use of an aortic balloon within 15-30min after Ovation stent graft ring inflation would resolve any inflow stenosis, which may reach 60%, at the level of the sealing rings. Moreover, we estimated the potential hemodynamic compromise in these patients during rest and exercise. Following 3-dimensional reconstruction of AAA models, cross-sectional area of the infrarenal aorta just proximal the sealing mechanism (A aort, R aort, respectively) and internal area at the site of stenosis (A int, R int, respectively) were measured for 83. Forty-nine patients were managed without and 34 with an aortic balloon use. Pressure drop during rest and exercise was estimated. Technical success was 98% and there were no perioperative deaths, one type-I endoleak, and 12 (14.5%) type-II endoleaks. Median A int and R int were significantly reduced compared to A aort [55% reduction, 143 (range 28-380) mm2 vs 314 (range 177-531) mm2, P value <0.001] and R aort [42% reduction, 6.75 (range 3-11) mm vs 10 (range 7.5-13) mm, P value <0.001]. The observed stenosis was significantly less for patients in whom an aortic balloon was used intraoperatively (area reduction 36 vs 59%, P value=0.009). This stenosis caused a statistically significant, but clinically insignificant ΔP in both groups during rest (0.13 vs 0.06mmHg, P value=0.02) and exercise (1 vs 0.5mmHg, P value=0.02). The advantages of the unique sealing mechanism of the Ovation device seem to be accompanied by an inflow stenosis which is significantly reduced when neck molding with an aortic balloon is used. Overall, the hemodynamic impact of this abnormality seems to be clinically insignificant at 1-month follow-up.