Significance of Initial Aortic Aneurysm Pressure Sensor Readings Varies with Aortic Endograft Design

Abstract

The differences in implantable pressure sensor aneurysm sac readings were compared following endovascular aneurysm repair (EVAR) among three different stent grafts. From January 2006 to March 2009, 51 aortic stent grafts were implanted along with the Endosure sensor. Grafts used were Zenith, Talent, and Excluder. In the present retrospective study, pulse ratios were measured intraoperatively before and after aneurysm sac exclusion and in follow-up (within 30days). Analysis of variance was used to determine significance. The average aneurysm size that was repaired was 5.75cm (range: 4-8.5cm); 41 patients (80.4%) being male with an average age of 76.3years (range: 58-90years). Thirty-four grafts were Zenith, 9 were Talent, and 8 were Excluder. The average pre-aneurysm exclusion pulse ratios for the Zenith, Talent, and Excluder were 1.00, 1.08, and 0.95 (p=0.18), respectively. The average post-aneurysm exclusion pulse ratios were 0.34, 0.67, and 0.35, respectively (p=0.003). Pulse ratios at the time of follow-up (within 30days) were 0.17, 0.22, and 0.11, respectively (p=0.44). Nine of 51 (17.6%) patients had a reduction of pulse ratio of less than 30% after endograft implantation. Five of those 9 patients (55.5%) had the Talent endograft, although there was no angiographic evidence of endoleak. The Talent graft has significantly higher pulse ratios following endograft implantation despite having no angiographic evidence of endoleak when compared to the Zenith and Excluder grafts. However, the pulse ratios decreased to levels similar to Zenith and Excluder within 30days of endograft implantation. This suggests that the Talent endograft may have increased porosity initially. If pulse ratios do not appropriately decrease immediately after device implantation, further angiographic imaging may not be necessary if no obvious endoleak is seen.